Article

Lipocalin 2 as A Potential Diagnostic and/or Prognostic Biomarker in Prostate, Lung and Liver Cancer

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Abstract

Lipocalin 2 (LCN2) is a 25 kDa secreted protein, initially purified from neutrophil granules, and mainly expressed in immune cells, hepatocytes, renal cells, prostate, cells of the respiratory tract and cardiomyocytes. LCN2 belongs to the family of lipocalins known for their ability to traffic small hydrophobic molecules such as lipids and retinoids. Due to its ability to sequester iron-containing bacterial siderophores, LCN2 plays an essential part in the innate immunity as well as in the regulation of the cellular iron metabolism. Altered LCN2 expression occurs in di- verse pathological conditions, including kidney disease, obesity, steatohepatitis, inflammation and malignant transformation. In recent years, LCN2 gained attention as a potential biomarker in cancer as it is protease resistant and thus easily detectable in blood, urine, tissue and other body fluids. In line, numerous peer-reviewed reports established the LCN2 overexpression in cancers of diverse histological background. Apparently, LCN2 has contradictory roles in dif- ferent types of cancers. While it facilitates tumorigenesis by promoting survival, growth, inva- sion and metastasis, other studies report a negative correlation of LCN2 and disease outcome. Particularly, LCN2 suppression promoted cell proliferation, migration, invasion as well as the switch from epithelial to mesenchymal state. The underlying molecular mechanisms of the complex and ambiguous role of LCN2 in malignant tumor development and progression are not completely clarified yet. The following review focuses on major findings of LCN2 as a po- tential diagnostic and/or prognostic biomarker in prostate, lung and liver cancer, representing worldwide three of the cancers with the highest estimated incidence, mortality, and prevalence. In addition, we will highlight the progress of knowledge in understanding molecular pathways and regulation processes of LCN2 in those cancer types.

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... LCN2 is a 25-kDa secreted glycoprotein with various physiological and pathophysiological functions [18]. Furthermore, LCN2 has been discussed as a prognostic and/or diagnostic marker in various types of cancer including PCa [19,20]. Nevertheless, the exact mechanism on how LCN2 is connected to metastatic spread still remains unclear. ...
... Previously, we reviewed LCN2 studies performed in prostate, lung and liver cancer highlighting the contradictory role of LCN2 in those cancer types [19]. Human PC-3 cells are suitable as a metastatic model to investigate PCa progression [42,45], whereas A549 carcinoma cells are a common model to study lung cancer [46]. ...
... LCN2 is involved in various physiological and pathophysiological cellular processes. It is discussed as a prognostic and/or diagnostic marker in different types of cancer [19]. Nevertheless, there are only limited studies investigating regulatory aspects of LCN2 expression in PCa [21,22,36,41,51,62]. ...
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Prostate cancer (PCa) is one of the most common and deadly cancers in men worldwide. The surrounding tumor microenvironment (TME) is important in tumor progression, as cytokines and soluble mediators including tumor necrosis factor (TNF-α) or lipocalin-2 (LCN2) can influence tumor growth and formation of metastasis. The exact mechanisms on how these pleiotropic factors affect PCa are still unknown. In this study, we showed for the first time that LCN2 mRNA and protein expression are strongly inducible by TNF-α in the highly metastatic human PCa cell line PC-3. In addition, we observed higher levels of secreted LCN2 in cell culture medium of TNF-α-treated PC-3 cells. We found that different signaling pathways such as p38, NF-κB or JNK were activated shortly after TNF-α treatment. Moreover, the mRNA levels of IL-1β and IL-8 were also significantly increased after 24 h stimulation. Mechanistically, the NF-κB pathway and the JNK signaling axis are directly responsible for LCN2 upregulation. This was shown by the fact that pretreatment with the JNK inhibitors SP600125 or JNK-IN-8 strongly downregulated phosphorylation of c-Jun protein and markedly reduced TNF-α-mediated LCN2 upregulation in PC-3 cells. Likewise, the NF-κB inhibitor QNZ was able to repress TNF-α-induced LCN2 expression in PC-3 cells. Taking into consideration that LCN2 has been described as a tumor promoting factor in PCa, our results indicate that JNK regulates LCN2 expression and unmasks the JNK signaling axis as a possible therapeutic target for patients with PCa.
... LCN2 has recently attracted the attention to its role in prognosis and diagnosis in various cancers, including colorectal and breast cancer [16,17]. We recently reviewed the potential roles of LCN2 in diagnosis and prognosis in prostate, pulmonary and hepatic cancer [18]. We came to the conclusion that LCN2 has widely heterogeneous roles in different cancer types, affecting frequently in a contradictory manner the cell proliferation, migration, invasion and metastasis pathways, leaving the presence of LCN2 in the tumor environment under the need of vast investigation [18]. ...
... We recently reviewed the potential roles of LCN2 in diagnosis and prognosis in prostate, pulmonary and hepatic cancer [18]. We came to the conclusion that LCN2 has widely heterogeneous roles in different cancer types, affecting frequently in a contradictory manner the cell proliferation, migration, invasion and metastasis pathways, leaving the presence of LCN2 in the tumor environment under the need of vast investigation [18]. ...
... Specifically in HCC, LCN2 expression has been described in several in vivo and in vitro studies, where it is always higher expressed in the tissue as well as in the serum of HCC patients compared to healthy subjects [18]. LCN2 expression inhibits proliferation, invasion and metastasis, with the ability to reverse the epithelial to mesenchymal transition process, suggesting LCN2 as a potential metastasis suppressor and a therapeutic target against HCC [19]. ...
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Hepatocellular carcinoma (HCC) is one of the most prevalent and deadly cancers worldwide. Therefore, current global research focuses on molecular tools for early diagnosis of HCC, which can lead to effective treatment at an early stage. Perilipin 5 (PLIN5) has been studied as one of the main proteins of the perilipin family, whose role is to maintain lipid homeostasis by inhibiting lipolysis. In this study, we show for the first time that PLIN5 is strongly expressed in tumors of human patients with HCC as well as in mouse livers, in which HCC was genetically or experimentally induced by treatment with the genotoxic agent diethylnitrosamine. Moreover, the secreted acute phase glycoprotein Lipocalin 2 (LCN2) established as a biomarker of acute kidney injury, is also proven to indicate liver injury with upregulated expression in numerous cases of hepatic damage, including steatohepatitis. LCN2 has been studied in various cancers, and it has been assigned roles in multiple cellular processes such as the suppression of the invasion of HCC cells and their metastatic abilities. The presence of this protein in blood and urine, in combination with the presence of α -Fetoprotein (AFP), is hypothesized to serve as a biomarker of early stages of HCC. In the current study, we show in humans and mice that LCN2 is secreted into the serum from liver cancer tissue. We also show that AFP-positive hepatocytes represent the main source for the massive expression of LCN2 in tumoral tissue. Thus, the strong presence of PLIN5 and LCN2 in HCC and understanding their roles could establish them as markers for diagnosis or as treatment targets against HCC
... Knockdown of LCN2 is known to affect tumorigenic markers and the EMT process in various cancers [12,17]. Our results show decreased protein expression of fibronectin, connexin 43 (Cx43) and nuclear factor kappa inhibitor zeta (IκBζ) when LCN2 was transiently downregulated with 35 nM siLCN2 in PC-3 cells ( Figure 2C). ...
... Presently, simple somatic mutations and copy number variations of LCN2 are more frequent described in other malignancies than PCa (Table S3). Although there is already discussion whether LCN2 can be used as a reliable biomarker [17,19], there is still a lack of understanding on its exact function in tumor progression, especially in PCa. ...
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... Structurally, it belongs to the lipocalin protein family sharing a highly compact hydrophobic β-barrel fold adapted to bind and transport a variety of hydrophobic ligands. Altered LCN2 expression occurs under diverse pathological conditions, including kidney disease, obesity, and acute and chronic inflammatory liver disease [2][3][4]. Upon intoxication, infection, inflammation, and other forms of cellular stress, LCN2 is rapidly induced in injured hepatocytes [5]. As a characteristic of an acute phase protein, LCN2 expression is stimulated by inflammatory cytokines including IL-6, IL-1β, and TNF-α [6,7]. ...
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Cancer remains one of the major cause of death in the Western world. Although, it has been demonstrated that new therapies can improve the outcome of cancer patients, still many patients relapse after treatment. Therefore, there is a need to identify novel factors involved in cancer development and/or progression. Recently, neutrophil gelatinase-associated lipocalin (NGAL) has been suggested as a key player in different cancer types. Its oncogenic effect may be related to the complex NGAL/MMP-9. In the present study, NGAL was analyzed at both transcript and protein levels in different cancer types by analysing 38 public available microarray datasets and the Human Protein Atlas tool. NGAL transcripts were significantly higher in the majority of solid tumors compared to the relative normal tissues for every dataset analyzed. Furthermore, concordance of NGAL at both mRNA and protein levels was observed for 6 cancer types including bladder, colorectal, liver, lung, ovarian, and pancreatic. All metastatic tumors showed a decrease of NGAL expression when compared to matched primary lesions. According to these results, NGAL is a candidate marker for tumor growth in a fraction of solid tumors. Further investigations are required to elucidate the function of NGAL in tumor development and metastatic processes.
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The EGFR tyrosine kinase inhibitors (TKIs) demonstrate efficacy in NSCLC patients whose tumors harbor activating EGFR mutations. However, patients who initially respond to EGFR TKI treatment invariably develop resistance to the drugs. Known mechanisms account for approximately 70% of native and acquired EGFR TKI resistance. In the current study we investigated a novel mechanism of NSCLC resistance to erlotinib. Experimental Design: The mechanisms of acquired erlotinib resistance were evaluated by microarray analysis in thirteen NSCLC cell lines and in vivo in mice. Correlations between plasma neutrophil gelatinase associated lipocalin (NGAL) levels, erlotinib response and the EGFR mutational status were assessed in advanced stage NSCLC patients treated with erlotinib. In 5 of 13 NSCLC cell lines NGAL was significantly upregulated. NGAL knockdown in erlotinib-resistant cells increased erlotinib sensitivity in vitro and in vivo. NGAL overexpression in erlotinib-sensitive cells augmented apoptosis resistance. This was mediated by NGAL-dependent modulation of the pro-apoptotic protein Bim levels. Evaluation of the plasma NGAL levels in NSCLC patients that received erlotinib revealed that patients with lower baseline NGAL demonstrated a better erlotinib response. Compared to patients with wild type EGFR, patients with activating EGFR mutations had lower plasma NGAL at baseline and weeks 4 and 8. Our studies uncover a novel mechanism of NGAL-mediated modulation of Bim levels in NSCLC that might contribute to TKI resistance in lung cancer patients. These findings provide the rationale for the further investigations of the utility of NGAL as a potential therapeutic target or diagnostic biomarker.
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HER2-positive breast cancer initially responds to trastuzumab treatment, but over time, resistance develops and rapid cancer progression occurs, for which various explanations have been proposed. Here we tested the hypothesis that induction of the unfolded protein response (UPR) could override HER2 inhibition by trastuzumab, leading to the re-activation of growth signaling and the activation of the downstream target Lipocalin 2 (LCN2). Trastuzumab significantly inhibited the basal expression of LCN2 in HER2(+) SKBr3 human breast cancer cells. The induction of the UPR completely abrogated trastuzumab-mediated LCN2 downregulation, and, in fact caused an increase in transcription and secretion of LCN2 over baseline. Reduction of the UPR using 4-phenyl butyric acid (PBA) a chemical chaperone that ameliorates ER stress, restored trastuzumab-mediated inhibition. Inhibition of the PI3K/AKT signaling pathway in trastuzumab-treated/UPR-induced SKBr3 cells partially reduced the upregulation of LCN2. These results suggest that the UPR is a possible way to override the effect of trastuzumab in HER2(+) cancer cells.
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Tumor cells adapt to endoplasmic reticulum (ER) stress through a set of conserved intracellular pathways, as part of a process termed the unfolded protein response (UPR). The expression of UPR genes/proteins correlates with increasing progression and poor clinical outcome of several tumor types, including prostate cancer. UPR signaling can activate NF-κB, a master regulator of transcription of pro-inflammatory, tumorigenic cytokines. Previous studies have shown that Lipocalin 2 (Lcn2) is upregulated in several epithelial cancers, including prostate cancer, and recently Lcn2 was implicated as a key mediator of breast cancer progression. Here, we hypothesize that the tumor cell UPR regulates Lcn2 production. We interrogated Lcn2 regulation in murine and human prostate cancer cells undergoing pharmacological and physiological ER stress, and tested UPR and NF-κB dependence by using pharmacological inhibitors of these signaling pathways. Induction of ER stress using thapsigargin (Tg), a canonical pharmacologic ER stress inducer, or via glucose deprivation, a physiologic ER stressor present in the tumor microenvironment, upregulates LCN2 production in murine and human prostate cancer cells. Inhibition of the UPR using 4-phenylbutyric acid (PBA) dramatically decreases Lcn2 transcription and translation. Inhibition of NF-κB in prostate cancer cells undergoing Tg-mediated ER stress by BAY 11-7082 abrogates Lcn2 upregulation. We conclude that the UPR activates Lcn2 production in prostate cancer cells in an NF-κB-dependent manner. Our results imply that the observed upregulation of Lipocalin 2 in various types of cancer cells may be the direct consequence of concomitant UPR activation, and that the ER stress/Lipocalin 2 axis is a potential new target for intervention in cancer progression.
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Neutrophil gelatinase-associated lipocalin (NGAL a.k.a lipocalin 2, lnc2) is a secreted protein which can form a complex with matrix metalloproteinase-9 (MMP9). This MMP9/NGAL complex has been associated with metastasis. MMP9 and NGAL are detected in the urine of patients afflicted with many different types of cancer, including prostate cancer. The effects of p53, NF-κB and the androgen receptor (AR) on the expression of NGAL was examined in four prostate cancer cell lines. Prostate cancer cell lines that are AR negative and expressed either mutant or no p53 (DU145 and PC3) displayed higher levels of NGAL expression compared to the prostate cancer cell lines (LNCaP and 22Rv-1) which are AR positive and express wild type (WT) p53. Introduction of WT-p53 into the PC3 prostate cancer cell line, resulted in reduction of the levels of NGAL expression. Conversely, introduction of dominant negative (DN) p53 or a retroviral construct expressing NF-κB into LNCaP cells increased NGAL expression. NGAL expression had functional effects on the ability of the cells to form colonies in soft agar. Whereas suppression of WT-53 in LNCaP cells increased NGAL expression, the introduction of WT-p53 suppressed NGAL transcription activity in PC3 prostate cells which normally express high level of NGAL. NF-κB and p53 were determined to regulate NGAL expression by positive and negative mechanisms, respectively. Our data indicate that prostate cancer growth, progression and sensitivity to chemotherapeutic drugs are regulated in part by NGAL and may involve complex interactions between NGAL, MMP9, NF-κB and p53.
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Bile salts containing vesicles (bilosomes) represent a portentous vesicular carrier that showed prosperous results in delivering active moieties in the gastrointestinal tract (GIT). In this study, bilosomes were exploited to deliver sulphated polysaccharide-protein complexes of Enteromorpha intestinalis (EHEM) and enhance its activity against hepatocellular carcinoma as well as resist harsh GIT conditions. Bilosomes were prepared using the sodium salt of three different bile acids (cholic, deoxycholic, taurodeoxycholic) and two different non-ionic surfactants (Span 40 and 65). The effects of experimental variables were thoroughly studied to obtain an optimum formulation loading EHEM. The selected formulation (EH-Bilo-2) prepared with sodium cholate and Span 65 displayed nano-sized (181.1±16.80 nm) spherical vesicles with reasonable entrapment efficiency (71.60 ± 0.25%) and controlled release properties; and thus was investigated as anti-hepatocarcinogenic candidate for in vivo studies. Treatment of hepatocellular carcinoma (HCC) bearing rats with EH-Bilo-2 experienced significant decrease in serum α-fetoprotein, endoglin, lipocalin-2 and heat shock protein 70 levels versus the untreated counterparts. Furthermore, the photomicrographs of their liver tissue sections showed focal area of degenerated pleomorphic hepatocytes with fine fibrosis originating from the portal area. Thus, the optimized bilosomal formulation is a promising delegate for tackling hepatocellular carcinoma owing to its powerful anti-cancer and anti-angiogenic activity.
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Lipocalin-2 (LCN2) is a secreted adipokine that transports small hydrophobic molecules such as fatty acids and steroids. LCN2 limits bacterial growth by sequestering iron-containing siderophores and in mammalian liver protects against inflammation, infection, injury and other stressors. Because LCN2 modulates hepatic fat metabolism and homeostasis, we performed a comparative profiling of proteins and lipids of wild type (WT) and Lcn2-deficient mice fed either standard chow or a methionine- and choline-deficient (MCD) diet. Label-free proteomics and 2D-DIGE protein expression profiling revealed differential expression of BRIT1/MCPH1, FABP5, HMGB1, HBB2, and L-FABP, results confirmed by Western blotting. Gene ontology enrichment analysis identified enrichment for genes associated with mitochondrial membrane permeabilization and metabolic processes involving carboxylic acid. Measurements of mitochondrial membrane potential, mitochondrial chelatable iron pool, intracellular lipid peroxidation, and peroxisome numbers in primary hepatocytes confirmed that LCN2 regulates mitochondrial and peroxisomal integrity. Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight (MALDI-TOF) mass spectrometry imaging identified significant changes to sphingomyelins, triglycerides, and glycerophospholipids in livers of mice fed an MCD diet regardless of LCN2 status. However, two arachidonic acid-containing glycerophospholipids were increased in Lcn2-deficient livers. Thus, LCN2 influences peroxisomal and mitochondrial biology in the liver to maintain triglyceride balance, handle oxidative stress, and control apoptosis.
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Background: Some studies have reported differentially altered neutrophil gelatinase-associated lipocalin (NGAL) levels in several malignancies. We evaluated NGAL measured in plasma or urine as both prognostic and diagnostic marker for different types of human tumors. Methods: We performed systematic electronic searches in Medline, Embase and CRDTAS. Studies were included if they evaluated NGAL as a prognostic or diagnostic marker for human cancers. The selection of the studies, screening of the full texts and data extraction were conducted independently by 2 authors. We used the random-effects model for the meta-analyses. A methodological assessment was completed. Results: We included 35 studies dedicated to colorectal, pancreas, breast, thyroid, gastric, kidney, endometrial, brain, liver, lung, esophageal, oral and ovarian cancers. Our meta-analyses showed that, in patients with colorectal and breast cancer, positive NGAL expression was associated with a decrease of disease-free survival (hazard ratio [HR] = 2.27, 95% confidence interval [95% CI], 1.54-3.36; HR = 1.78, 95% CI, 1.33-2.38, respectively). NGAL was a negative prognostic marker of overall survival in colorectal (HR = 2.37, 95% CI, 1.68-3.34) and endometrial (HR = 4.38, 95% CI, 1.9-10.12) cancers. Discriminative power of NGAL between cancer patients and control was moderate in colorectal cancer (area under the curve [AUC] = 0.6; pooled sensitivity 0.56; pooled specificity 0.72), acceptable in pancreatic cancer (AUC = 0.8; pooled sensitivity 0.6; pooled specificity 0.8) and good in thyroid cancer (AUC = 0.9; pooled sensitivity 0.85; pooled specificity 0.96). Conclusions: NGAL determination in plasma and urine could be useful in the prognosis of colorectal and breast cancer, but its prognostic accuracy remains uncertain for other human tumors.
Article
Objective: Prostate specific antigen (PSA) with digital rectal examination is used for diagnosis of prostate cancer (PCa), where definite diagnosis can only be made by prostate biopsy. Recently neutrophil gelatinase-associated lipocalin (NGAL), a lipocalin family member glycoprotein, come into prominence as a cancer biomarker. This study is aimed to test serum NGAL as a diagnostic biomarker for PCa and discriminate PCa from benign prostatic hyperplasia (BPH). Material and methods: In this prospective study, 90 patients who underwent transrectal ultrasound-guided 12-core prostate biopsy between May 2015 and September 2015, were evaluated. Histopathologically diagnosed 45 PCa and 45 BPH patients were enrolled in this study. Serum NGAL and PSA levels of all participants were measured, then these data were evaluated by statistical programs. Results: When sensitivity fixed to 80% specificity of NGAL was better than PSA (49%, 31% respectively). Receiver operating characteristic (ROC) curve analysis showed that NGAL alone or its combined use with PSA have better area under curve (AUC) results than PSA alone (0.662, 0.693, and 0.623 respectively). Conclusion: In conclusion NGAL gave promising results such as increased sensitivity and a better AUC values in order to distinguish PCa from BPH. NGAL showed a potential to be a non-invasive biomarker which may decrease the number of unnecessary biopsies.
Article
Various, diverse molecules contribute to the tumor microenvironment and influence invasion and metastasis. In this review, the roles of neutrophil gelatinase-associated lipocalin (NGAL) and matrix metalloproteinase-9 (MMP-9) in the tumor microenvironment and sensitivity to therapy will be discussed. The lipocalin family of proteins has many important functions. For example when NGAL forms a complex with MMP-9 it increases its stability which is important in cancer metastasis. Small hydrophobic molecules are bound by NGAL which can alter their entry into and efflux from cells. Iron transport and storage are also influenced by NGAL activity. Regulation of iron levels is important for survival in the tumor microenvironment as well as metastasis. Innate immunity is also regulated by NGAL as it can have bacteriostatic properties. NGAL and MMP-9 expression may also affect the sensitivity of cancer cells to chemotherapy as well as targeted therapy. Thus NGAL and MMP-9 play important roles in key processes involved in metastasis as well as response to therapy. This article is part of a Special Issue entitled: Tumor Microenvironment Regulation of Cancer Cell Survival, Metastasis, Inflammation, and Immune Surveillance. Copyright © 2015. Published by Elsevier B.V.
Article
The lipocalins were originally classified as a widespread group of transport proteins for small hydrophobic molecules. Although they only share a limited sequence homology their 3D fold is conserved. This group of proteins has been implicated in a multitude of biological processes that most often become visible during disease formation. Lipocalin 2 (LCN2) serves as a siderocalin and protects against bacterial infections. In the liver, LCN2 expression is upregulated during inflammation and in response to cellular stress evolving protective effects during acute and chronic injury. LCN2 was shown to act as an adipokine in the pathogenesis of nonalcoholic fatty liver disease and in control of brown adipose tissue activation. In a nutritional model of nonalcoholic steatohepatitis, LCN2 was identified as a key factor that controls the expression of the perlipin 5 regulating cellular lipid droplet formation. We here summarize experimental and clinical findings linking LCN2 to fatty liver disease.
Article
Background: Metastasis is the primary cause of prostate cancer (PCa) lethality and poses a huge clinical obstacle. Lipocalin 2 (LCN2), a member of the lipocalin family, is aberrantly expressed in some human cancers and has been implicated in the progression of some tumors. However, the role of LCN2 in the metastatic capacity of prostate cancer (PCa) is poorly understood. Methods: LCN2 expression was examined by RT-qPCR and/or immunoblotting in human prostate tissue specimens and prostate cancer cell lines LNCaP, C4-2, 22RV1, PC3, DU-145, and PC3MM2. LCN2 protein level in human serum samples was determined by ELISA. Lentiviruses-mediated over-expression of LCN2 and knockdown of LCN2 was conducted to evaluate the role of LCN2 in cell migratory and invasive capacities of prostate cancer cells. Cell migration and invasion was examined by transwell chamber assay. Knockdown of SLUG by lentivirus was performed to investigate its role in LCN2-promoted cell migration and invasion in vitro (22RV1 cell line) and metastasis in vivo (tail vein metastasis assay in nude mice). Role of ERK signaling in LCN2-mediated up-regulation of SLUG was assayed by using ERK inhibitor U0126. Results: We confirmed that LCN2 levels were correlated positively with invasive prostate cancer in human tissue and serum samples, and were also consistently associated with the invasive capacity of prostate cancer cell lines. The over-expression of LCN2 in 22RV1 cells (not highly invasive) promoted the epithelial-mesenchymal transition (EMT), increasing cell motility and invasiveness, while the knockdown of LCN2 in PC3 cells (highly invasive) inhibited EMT, decreasing cell motility and invasiveness. Among the multiple EMT transcription factors, LCN2 specifically induces the expression of SLUG, which was shown here to be required for the LCN2-induced increase in the invasive capacity of prostate cancer cells both in vitro and in vivo. Mechanistically, LCN2 promoted SLUG expression via activating ERK signaling pathway. Conclusion: LCN2 plays an important role in promoting cell migration and invasion of prostate cancer by inducing EMT through the ERK/SLUG axis. Therefore, targeted inhibition of LCN2 may represent a therapeutic strategy to prevent the metastasis of prostate cancer.
Article
Prognosis in patients with lung cancer is poor. Neutrophil gelatinase-associated lipocalin (NGAL) and matrix metalloproteinase-9 (MMP-9) are proteins involved in the invasion and metastases of cancer. The objective of this study is to determine if there is a relationship between tumor expression of NGAL and MMP-9 in lung adenocarcinoma patients with prognosis and overall survival. Retrospective analysis was made of patients with lung adenocarcinoma treated at Medica Sur Hospital between 2005 and 2013. Tumor tissue was analyzed for NGAL and MMP-9 expression by immunohistochemistry. We identified 41 patients. Mean overexpression in tumoral tissue of NGAL was 70 % and 30 % for MMP-9. Univariate analysis revealed that prognostic factors associated with overall survival (OS) were NGAL expression and stage at diagnosis. Median OS for NGAL expression <70 % was 45.7 months (95 % CI; 15.2–76.2) and for patients with ≥70 % 4.6 months (95 % CI; 0.5–18.8; P < 0.0001), and for stage at diagnosis (stages I and II mean not reached), stage III mean OS 15.57 months (95 % CI; 9.8–21.2) and stage IV 9.6 months (95 % CI; 0.8–18.4. P = 0.002). No differences in OS were found for expression of MMP-9. Multivariate analysis revealed significance for OS in NGAL expression (HR 5.01 [95 % CI; 1.68–14.93] P = 0.004) and stage at diagnosis (HR 2.05 [95 % CI 1.30–3.22] P = 0.002). Tumoral tissue expression of NGAL ≥70 % confers a worse prognosis compared to those who did not. NGAL is an independent prognostic factor of stage at diagnosis.
Article
We investigated urinary nerve growth factor (NGF) as a novel urinary biomarker for high-grade prostate cancer (PCa). After institutional review board approval for a prospective pilot study, we enrolled men at the preoperative visit before robotic-assisted radical prostatectomy. Demographics, urinary flow parameters, and urine samples were collected. Urinary NGF and urinary creatinine were obtained in the translational science laboratory. Pathologic and postoperative demographics were collected after surgery. NGF is the primary outcome variable (dependent variable). The pathologic Gleason score (ordinal variable≤6, 7, and ≤8) served as an independent grouping variable. Multivariate analysis using a general linear model was conducted to investigate associations between independent variables and NGF (dependent variable) after adjusting for urinary concentration and volume. We enrolled and analyzed urine samples and pathologic data from 115 subjects. Patient pathology included 24% (n = 28) Gleason score 6 or less, 68% (n = 78) Gleason score 7, and 8% (n = 9) Gleason score 8 or greater. Perineural invasion was more prevalent in higher-grade disease (P<0.001). The median NGF level was 24.1pg/ml (range: 0.16-270.5pg/ml) and was transformed to the log base 10 scale. Total bladder volume, urinary creatinine level, prostate-specific antigen level, and diabetes were correlated with the Log NGF. In a general linear model, adjusting for bladder volume and urinary creatinine, increasing Log10 NGF was associated with higher Gleason score (Gleason category≤6, 7, and≥8; P = 0.003). Urinary NGF may be a biomarker for higher-grade PCa. Our pilot study suggests further investigation is warranted to determine whether urinary NGF could provide unique additional information in patients with PCa.
Article
Background: Lipocalin-2 (LCN2) is a member of the lipocalin superfamily, and it has an important role in the regulation of cellular oncogenesis and apoptosis. However, the role for LCN2 in prostate cancer remains unclear. Method: LCN2 expression has been determined by Western blotting, qRT-PCR, and immunohistochemistry in the human prostate cell lines PC3, DU145, LNCaP, and 22Rv, and in human prostate tissue array. In this study, we identified shRNA-LCN2 to determine the role of LCN2 in prostate-cancer cell proliferation, migration, and invasion. Cell proliferative ability was measured by MTT, colony-formation, and cell-cycle analysis. The role of LCN2 in prostate-cancer cell migration and invasion was analyzed by cell-migration assay and Matrigel invasion assay. The effect of LCN2 knockdown on prostate tumor growth was assessed in a subcutaneous xenograft model. Results: LCN2 protein and mRNA expression are higher in PC3 and DU145 cells than in LNCaP and 22Rv cells, and prostate cancer tissue correlated significantly with tumor differentiation (P < 0.017) and Gleason's grade (P < 0.02). LCN2 knockdown in PC3 and DU145 cells decreased cell proliferation, colony formation, cell cycle arrest, migration, and invasion. Conversely, LCN2 overexpression in 22Rv cells produced the opposite effect. Subcutaneous xenografts in mice models showed decreased tumor growth in the LCN2-knockdown mice. Conclusions: Our results suggest that LCN2 might play an important role in regulation of proliferation and invasion of human prostate cancer, and that it can be a valuable marker of prostate cancer progression.
Article
Matrix metalloproteinases (MMPs) play a central role in tumor invasion and metastasis. Increased expression of MMPs occurs during development of hepatocellular carcinoma (HCC) in humans following infection with hepatitis B virus (HBV). Woodchucks are used as an animal model for hepadnavirus-induced HCC. All woodchucks infected chronically with woodchuck hepatitis virus (WHV), a virus that is closely related to HBV, develop HCC. In the present study MMPs and related molecules were investigated in woodchucks to better understand the mechanisms of extracellular matrix remodeling in HCC. Three groups of samples were studied: liver and HCC tissues from animals infected with WHV and age- and gender-matched normal liver from animals not infected with WHV. New partial gene sequences for woodchuck MMP-2, MMP-7, and MMP-9 as well as their inhibitors NGAL, TIMP-1, and TIMP-2 were identified and used for determination of expression levels in liver and HCC by qRT-PCR. Compared to liver of WHV-naïve woodchucks, high levels of MMP-1, MMP-2, MMP-7, NGAL, and TIMP-1 were detected in liver of animals infected with WHV. However, no differences were found for TIMP-2. MMP-9 expression was higher in HCC than in liver of animals not infected with WHV. Immunohistochemical staining demonstrated that MMP-9 immunoreactivity was most intense in HCC, correlating with the progression of liver disease. Upregulation of MMP-9 in HCC was confirmed by Western blotting and zymography analysis. Furthermore, the activity of woodchuck MMPs was suppressed by BiPS, a common inhibitor of mammalian MMPs. These results suggest the use of MMP inhibitors as a potential HCC treatment strategy that could be explored in woodchucks. J. Med. Virol. 9999:XX-XX, 2013. © 2013 Wiley Periodicals, Inc. J. Med. Virol. © 2013 Wiley Periodicals, Inc.
Article
Iron is an essential nutrient that facilitates cell proliferation and growth. However, iron also has the capacity to engage in redox cycling and free radical formation. Therefore, iron can contribute to both tumour initiation and tumour growth; recent work has also shown that iron has a role in the tumour microenvironment and in metastasis. Pathways of iron acquisition, efflux, storage and regulation are all perturbed in cancer, suggesting that reprogramming of iron metabolism is a central aspect of tumour cell survival. Signalling through hypoxia-inducible factor (HIF) and WNT pathways may contribute to altered iron metabolism in cancer. Targeting iron metabolic pathways may provide new tools for cancer prognosis and therapy.
Article
Aim of the study was to investigate the value of serum and bile neutrophil gelatinase-associated lipocalin (NGAL) for distinguishing malignant strictures caused by cholangiocarcinoma (CCA) or pancreatic cancer from benign biliary strictures. The study was performed prospectively on patients admitted for endoscopic or radiologic biliary decompression. Forty patients with dilated biliary ducts, including 16 cases of CCA, 6 cases of pancreatic cancer, and 18 cases of benign biliary stricture were enrolled. Their sera and bile were collected to measure NGAL. Routine biochemistry including measurement of serum levels of carbohydrate antigens (CA) 19-9 and carcinoembryonic antigen (CEA) was also performed. The serum CA19-9, serum CEA, and bile NGAL levels were significantly increased in patients with malignant strictures as compared with patients with benign biliary diseases. Serum NGAL had no significant value for discriminating between malignant and benign biliary strictures. Bile NGAL levels had a receiver characteristic area under the curve of 0.74, sensitivity 77.3, and specificity 72.2% for discriminating between pancreatobiliary cancer and benign biliary diseases. Bile NGAL and serum CA19-9 were independent parameters and their combined use improved diagnostic accuracy (sensitivity 91%, negative predictive value 85.7%). We conclude that measurement of biliary, but not serum NGAL, may differentiate malignant pancreatobiliary from benign biliary strictures, serving as a complementary biomarker for serum CA19-9.
Article
Lung cancer is the leading worldwide cause of cancer deaths. Smoking is the dominant cause of lung cancer and smoking cessation is the established method to reduce lung cancer mortality. While lung cancer risk is reduced in former smokers, they have a lifelong increase in risk, compared to never-smokers. Novel chemoprevention strategies, such as oral or inhaled prostacyclin analogs, hold promise for these subjects. Low-dose spiral computed tomography screening reduced lung cancer mortality by 20% in high-risk heavy smokers older than 50 years. However, the high false-positive rate (96%) means that screened patients required controlled follow-up in experienced centers. An increasing percentage of patients with advanced lung cancer have molecular drivers in genes for which oral tyrosine kinase inhibitors have been developed.
Article
Neutrophil gelatinase-associated lipocalin (NGAL), a member of the lipocalin family, has been found to be overexpressed in a variety of tumors, including lung adenocarcinomas. However, the mechanism by which NGAL expression is regulated in lung carcinoma needs further evaluation. In this study, immunohistochemistry was employed to analyze the expression of NGAL in lung carcinoma tissue samples, including lung squamous carcinomas, adenocarcinomas, adenosquamous carcinomas and bronchial alveolar cell carcinomas. The results showed that NGAL was expressed in 82.61% (19/23) of the samples. RT-PCR and immunofluorescent staining showed that NGAL was localized to the cytoplasm in lung carcinoma cell lines. To explore the transcriptional regulation mechanism of NGAL basal expression in lung carcinoma, a 1515-bp fragment (-1431 to +84) of the NGAL promoter region was cloned and a series of deletion and mutation constructs were generated. These constructs were analyzed using the luciferase reporter assay. The results indicated that the cis-acting elements important for the basal activity of NGAL transcription were likely located between -152 and -141. Further analysis using site-directed mutagenesis and the luciferase reporter assay suggested that the C/EBP binding sites were responsible for the activity of the NGAL promoter. Finally, the binding ability and specificity of the transcription factors were determined by electrophoretic mobility-shift assay (EMSA). The results showed that C/EBPβ was able to bind to the -152 and -141 segments. Taken together, these findings suggest that NGAL is expressed in lung carcinomas and that NGAL expression is mediated by the binding of C/EBPβ to the -152 and -141 segment of the NGAL promoter.
Article
The Northeastern region of Thailand is well known to have high incidence of bile duct cancer known as cholangiocarcinoma. So there is a continued need to improve diagnosis and treatment, and discovery of biomarkers for early detection of bile duct cancer should greatly improve treatment outcome for these patients. The secretome, a collection of proteins secreted from cells, is a useful source for identifying circulating biomarkers in blood secreted from cancer cells. Here a Hollow Fiber Bioreactor culture system was used for enrichment of cholangiocarcinoma secretomes, since this culture system mimics the dense three-dimensional microenvironment of the tumor found in vivo. Two-dimensional fluorescence difference gel electrophoresis using a sensitive Fluor saturation dye staining, followed by LC/MS/MS, was used to compare protein expression in the secretomes of cells cultured in the Hollow Fiber system and cells cultured in the monolayer culture system. For the first time, the 2D-patterns of cholangiocarcinoma secretomes from the two culture systems could be compared. The Hollow Fiber system improved the quality and quantity of cholangiocarcinoma secreted proteins compared to conventional monolayer system, showing less interference by cytoplasmic proteins and yielding more secreted proteins. Overall, 75 spots were analyzed by LC/MS/MS and 106 secreted proteins were identified. Two novel secreted proteins (C19orf10 and cystatin B) were found only in the Hollow Fiber system and were absent from the traditional monolayer culture system. Among the highly expressed proteins, 22 secreted soluble proteins were enriched by 5 fold in Hollow Fiber system compared to monolayer culture system. The Hollow Fiber system is therefore useful for preparing a wide range of proteins from low-abundance cell secretomes.
Article
Aim: Neutrophil gelatinase-associated lipocalin (NGAL) and its cell surface receptor, NGALR, have been implicated in tumorigenesis and tumor progression of various human malignant neoplasms. In particularly, it has been demonstrated that NGAL is overexpressed in hepatocellular carcinoma (HCC) tissues and closely associated with the proliferation and invasion of HCC cells. The aim of this study was to investigate the clinical significance of NGAL and NGALR in HCC. Methods: Expression of NGAL and NGALR was evaluated by immunohistochemistry in tumor tissues from 138 patients who underwent curative resection of HCC. The association of NGAL or NGALR expression with the clinicopathologic features was analyzed. Univariate and multivariate analyses were performed to evaluate the prognostic value of NGAL and/or NGALR expression for HCC patients. Results: The expression levels of NGAL and NGALR were both up-regulated in HCC tissues, and to be associated with vascular invasion (both P=0.03), TNM stage (both P=0.004), and tumor recurrence (both P<0.001). A positive correlation between expression of the two markers was also observed (r=0.89; P<0.001). Additionally, survival analysis showed that high expression of NGAL or NGALR was significantly associated with poor prognosis for patients with HCC (both P=0.003). Patients with high expression of both NGAL and NGALR had a shorter overall survival (P<0.001) than those with low expression of both. Furthermore, multivariate analysis showed both NGAL and NGALR were independent predictors of overall survival. Conclusion: Our data demonstrate for the first time that the up-regulations of NGAL and NGALR expression in HCC were both significantly correlated with unfavorable clinicopathologic features and independent poor prognostic factor for overall survival in patients. These findings suggest that NGAL and NGALR expression might be served as novel prognostic factors and potential therapeutic targets in HCC.
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Lipocalin 2 (LCN2) is a secreted, iron-binding glycoprotein that is abnormally expressed in some malignant human cancers. However, the roles of LCN2 in hepatocellular carcinoma (HCC) cells are unknown. In this study, we suggested the LCN2 and LCN2R were weak detected in the HCC cell lines, LCN2 and LCN2R were found to be down-regulated in tumor tissues in 16 HCC patients. MTT, DAPI, TUNEL, and flow cytometry analyses revealed that LCN2 overexpression dramatically inhibited cell viability, induced apoptosis features of cell-cycle arrest in sub-G1 phase, in DNA fragmentation, and in condensation of chromatin in Huh-7 and SK-Hep-1 cells. Western blots were used to detect the activation of caspase, pro-apoptosis, and anti-apoptosis protein expression in overexpress-LCN2 HCC cells. LCN2-induced apoptosis was characterized by cleavage of caspase-9, -8, -3, and PARP protein, and a reduction in the mitochondrial membrane potential (MMP). Furthermore, LCN2 also enhanced the down-regulated Bcl-2 and up-regulated the expression of Bax. In addition, our experiments with caspase inhibitors LEHD-FMK and IETD-FMK prevent LCN2-induced apoptosis. We also demonstrated that treatment of overexpress-LCN2 HCC cells with the LCN2 neutralized antibody also significantly attenuated LCN2-induced cell apoptosis. These findings indicate that LCN2 overexpression can effectively induce apoptosis of HCC cells and may be used as a potent therapy against human HCC.
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Distant metastasis is one of the leading causes of lung cancer death. Detecting the early-stage molecular alternations in primary tumors, such as gene expression differences, provides a "prognostic" value to the precaution of tumor metastasis. The aim of this article is to screen and identify the metastasis-related genes in human squamous cell lung carcinoma. Primary tumor tissues of nine patients with subsequent metastasis and eight patients without metastasis were selected to perform the gene microarray experiment. GO and pathway analyses were used to determine the differentially expressed genes. Two identified genes were further validated by real-time quantitative reverse transcription polymerase chain reaction (PCR) (real-time qRT-PCR). Two hundred and thirty-eight differentially expressed genes were detected in gene chip experiment, including 51 up-regulated genes and 187 down-regulated genes. These genes were involved in several cellular processes, including cell adhesion, cell cycle regulation, and apoptosis. GO analysis showed that the differentially expressed genes participated in a wide ranging of metastasis-related processes, including extracellular region and regulation of liquid surface tension. In addition, pathway analysis demonstrated that the differentially expressed genes were enriched in pathways related to cell cycle and Wnt signaling. Real-time qRT-PCR validation experiment of LCN2 and PDZK1IP1 showed a consistent up-regulation in the metastasis group. The metastasis of human squamous cell lung carcinoma is a complex process that is regulated by multiple gene alternations on the expression levels. The 238 differentially expressed genes identified in this study presumably contain a core set of genes involved in tumor metastasis. The real-time qRT-PCR results of PDZK1IP1 and LCN2 validated the reliability of this gene microarray experiment.
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Cancer is one of the leading causes of death, and there is an urgent need for new biomarkers and therapeutic targets. The progesterone receptor membrane component 1 (Pgrmc1) protein is upregulated in multiple types of cancer, and Pgrmc1 is required for tumor cell proliferation, motility and tumor formation in vivo. Furthermore, a small molecule inhibitor of Pgrmc1 suppressed the growth of lung, breast and cervical cancer cell lines. Recently, Pgrmc1 was identified as the sigma-2 receptor, a putative type of opioid receptor, and sigma-2 receptors are induced in cancers. However, Pgrmc1 shares no homology with known opioid or hormone receptors but is related to cytochrome b(5), and Pgrmc1 binds to heme and has reducing activity. In this study, we have analyzed Pgrmc1 levels in clinical tumor samples from squamous cell lung cancers (SCLC) and lung adenocarcinomas compared to corresponding nonmalignant tissue. Pgrmc1 levels increased significantly (p ≤ 0.05) in 12/15 SCLC samples and was elevated in poorly differentiated tumors. Pgrmc1 was highly expressed in SCLC cell lines, and SCLC cell survival was inhibited by siRNA knockdown of Pgrmc1 or the Pgrmc1 inhibitor AG-205. In adenocarcinomas, 6/15 tumors significantly had elevated Pgrmc1 levels, which correlated with patient survival. Pgrmc1 localizes to secretory vesicles in cancer cells, and Pgrmc1 was secreted by lung cancer cells. Furthermore, Pgrmc1 was significantly elevated in the plasma of lung cancer patients compared to noncancer patients. Together, the results demonstrate that Pgrmc1 is a potential tumor and serum biomarker, as well as a therapeutic target, for lung cancer.
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Prostate-specific antigen (PSA) is a protein produced by the prostate, and this protein may be elevated for several reasons, including prostatitis, benign prostatic hypertrophy and/or cancer. PSA is not cancer-specific, cannot be used as a cancer marker and it has been demonstrated that there is no level of PSA that is definitive for prostate cancer. The value of the PSA test varies when used for screening, diagnosis, prognosis or as a signal of disease recurrence. Misuse of the test for screening has created unnecessary anxiety and costs, and has led to the significant overdiagnosis and overtreatment of men. More important than whether or not to screen is how one acts upon the data from a single test; with the exception of extremely high double- or triple-digit levels of PSA, it is prudent only to use a single PSA determination as a baseline, with biopsy and cancer treatment reserved for those with significant PSA changes over time, or for those with clinical manifestations mandating immediate therapy. Using the PSA test to monitor disease progression or recurrence is appropriate, provided one understands that absolute levels of PSA are rarely meaningful; it is the relative change in PSA levels over time that provides insight, but not definitive proof of a cancerous condition necessitating therapy. PSA secretion is under hormonal control and thus PSA levels may be affected differently by the type of drug therapy, by the stage of a patients' disease, and by genetic factors suggesting some men are 'high PSA producers'. Until a validated alternative test for prostate cancer is found and adopted, the current flawed PSA test needs to be used more judiciously and not used for routine screening as studies have demonstrated that screening, as defined, does not lead to a reduction in patient mortality. All men, their families and their physicians need to understand the significant limitations of PSA testing.