Cancer biology & therapy (Canc Biol Ther )

Publisher: Landes Bioscience


Cancer, the second leading cause of death, is a heterogenous group of over 100 diseases. Cancer is characterized by disordered and deregulated cellular and stromal proliferation accompanied by reduced cell death with the ability to survive under stresses of nutrient and growth factor deprivation, hypoxia, and loss of cell-to-cell contacts. At the molecular level, cancer is a genetic disease that develops due to the accumulation of mutations over time in somatic cells. The phenotype includes genomic instability and chromosomal aneuploidy that allows for acceleration of genetic change. Malignant transformation and tumor progression of any cell requires immortalization, loss of checkpoint control, deregulation of growth, and survival. A tremendous amount has been learned about the numerous cellular and molecular genetic changes and the host-tumor interactions that accompany tumor development and progression. It is the goal of the field of Molecular Oncology to use this knowledge to understand cancer pathogenesis and drug action, as well as to develop more effective diagnostic and therapeutic strategies for cancer. This includes preventative strategies as well as approaches to treat metastases. With the availability of the human genome sequence and genomic and proteomic approaches, a wealth of tools and resources are generating even more information. The challenge will be to make biological sense out of the information, to develop appropriate models and hypotheses and to translate information for the clinicians and the benefit of their patients. Cancer Biology & Therapy aims to publish original research on the molecular basis of cancer, including articles with translational relevance to diagnosis or therapy. We will include timely reviews covering the broad scope of the journal. The journal will also publish op-ed pieces and meeting reports of interest. The goal is to foster communication and rapid exchange of information through timely publication of important results using traditional as well as electronic formats. The journal and the outstanding Editorial Board will strive to maintain the highest standards for excellence in all activities to generate a valuable resource.

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    Cancer Biology and Therapy website
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    Cancer biology & therapy (Online), Cancer biology & therapy, Cancer biology and therapy
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    Internet Resource, Computer File, Journal / Magazine / Newspaper

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Landes Bioscience

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Publications in this journal

  • Lulu Farhana, Marcia I Dawson, Joseph A Fontana
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    ABSTRACT: Abstract Aberrant regulation of microRNA expression in pancreatic cancers has been shown to play an important role in its inherent poor prognosis and malignant potential. MicroRNAs have also been shown to inhibit translation of genes by targeting the 3'-untranslated region (3-UTR) of mRNAs resulting in the inhibition of translation and often destruction of the mRNA. In the present study we investigated the role of the microRNA miR-202 in the apoptotic pathways of pancreatic cancer cells. The adamantyl-related molecule, 3-Cl-AHPC down-regulated expression of miR-202 and miR-578 resulting in the increased expression of mRNA and protein expression of their target genes, Max dimerization protein 1 (Mxd1/Mad1) and the Sin3A associated protein 18 (SAP18). Overexpression of pre-miR-202 led to diminished levels of Mxd1 and blocked the 3-Cl-AHPC-mediated increase in Mxd1 mRNA expression. The addition of the microRNA inhibitor 2'-O-methylated miR-202 enhanced the 3-Cl-AHPC-mediated increase of Mxd1 mRNA levels as well as 3-Cl-AHPC-mediated apoptosis. We found increased Mxd1 bound to the Sin3A repressor protein complex through its increased binding with HDAC-2 and subsequently enhanced transcriptional repression in cells as evidenced by increased HDAC activity. Mxd1 also repressed human telomerase reverse transcriptase (hTERT) mRNA expression through its increased binding to the hTERT promoter site and resulted in decreased telomerase activity in cells. Our results demonstrate that down regulation of miR-202 increased the expression of its target Mxd1, followed by Mxd1 recruitment to the Sin3A repressor complex and through its dimerization with Max, and increased repression of Myc-Max target proteins.
    Cancer biology & therapy 01/2015;
  • Stefano Indraccolo, Giovanni Randon, Elisabetta Zulato, Margherita Nardin, Camillo Aliberti, Fabio Pomerri, Alessandra Casarin, Maria Ornella Nicoletto
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    ABSTRACT: ABSTRACT Background: Recurrent type I endometrial cancer (EC) has poor prognosis and demands novel therapeutic approaches. Bevacizumab, a VEGF-A neutralizing monoclonal antibody, has shown clinical activity in this setting. To our knowledge, however, although some diabetic cancer patients treated with bevacizumab may also take metformin, whether metformin modulates response to anti-VEGF therapy has not yet been investigated. Here, we report the case of a patient with advanced EC treated, among other drugs, with bevacizumab in combination with metformin. Case presentation: The patient affected by relapsed EC G3 type 1, presented in march 2010 with liver, lungs and mediastinic metastases. After six cycles of paclitaxel and cisplatin she underwent partial response. Later on, she had disease progression notwithstanding administration of multiple lines of chemotherapy. In march 2013, due to brain metastases with coma, she began steroid therapy with development of secondary diabetes. At this time, administration of Bevacizumab plus Metformin improved her performance status. CT scans performed in this time window showed reduced radiologic density of the lung and mediastinic lesions and of liver disease, suggestive of increased tumor necrosis. Strong (18)F-FDG uptake by PET imaging along with high levels of monocarboxylate transporter 4 and lack of liver kinase B1 expression in liver metastasis, highlighted metabolic features previously associated with response to anti-VEGF therapy and phenformin in preclinical models. However, clinical benefit was transitory and was followed by rapid and fatal disease progression. Conclusion: These findings - albeit limited to a single case - suggest that tumors lacking LKB1 expression and/or endowed with an highly glycolytic phenotype might develop large necrotic areas following combined treatment with metformin plus bevacizumab. As metformin is widely used among diabetes patients as well as in ongoing clinical trials in cancer patients, these results deserve further clinical investigation.
    Cancer biology & therapy 01/2015;
  • Cancer biology & therapy 01/2015;
  • Kowit Yu Chong, Chih-Jung Hsu, Tsai-Hsien Hung, Han-Shu Hu, Tsung-Teng Huang, Tzu-Hao Wang, Chihuei Wang, Chuan-Mu Chen, Kong Bung Choo, Ching-Ping Tseng
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    ABSTRACT: ABSTRACT Multiple drug resistance (MDR) is a major obstacle to attenuating the effectiveness of chemotherapy to many human malignancies. Proteasome inhibition induces apoptosis in a variety of cancer cells and is recognized as a novel anticancer therapy approach. Despite its success, some multiple myeloma patients are resistant or become refractory to ongoing treatment by bortezomib suggesting that chemoresistant cancer cells may have developed a novel mechanism directed against the proteasome inhibitor. The present study aimed to investigate potential mechanism(s) of attenuation in a MDR cell line, MES-SA/Dx5. We found that compared to the parental human uterus sarcoma cell line MES-SA cells, MES-SA/Dx5 cells highly expressed the ABCB1 was more resistant to MG132 and bortezomib, escaping the proteasome inhibitor-induced apoptosis pathway. The resistance was reversed by co-treatment of MG132 and the ABCB1 inhibitor verapamil. The data indicated that ABCB1 might play a role in the efflux of MG132 from the MES-SA/Dx5 cells to reduce MG132-induced apoptosis. Furthermore, the canonical Wnt pathway was found activated only in the MES-SA/Dx5 cells through active β-catenin and related transactivation activities. Western blot analysis demonstrated that Wnt-targeting genes, including c-Myc and cyclin D1, were upregulated and were relevant in inhibiting the expression of p21 in MES-SA/Dx5 cells. On the other hand, MES-SA cells expressed high levels of p21 and downregulated cyclin D1 and caused cell cycle arrest. Together, our study demonstrated the existence and participation of ABCB1 and the Wnt pathway in an MDR cell line that attenuated proteasome inhibitor-induced apoptosis.
    Cancer biology & therapy 01/2015;
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    ABSTRACT: Abstract Plasminogen activator inhibitor (PAI)-1 is predictive of poor outcome in several types of cancer. The present study investigated the biological role for PAI-1 in ovarian cancer and potential of targeted pharmacotherapeutics. In patients with ovarian cancer, PAI-1 mRNA expression in tumor tissues was positively correlated with poor prognosis. To determine the role of PAI-1 in cell proliferation in ovarian cancer, the effects of PAI-1 inhibition were examined in PAI-1-expressing ovarian cancer cells. PAI-1 knockdown by small interfering RNA resulted in significant suppression of cell growth accompanied with G2/M cell cycle arrest and intrinsic apoptosis. Similarly, treatment with the small molecule PAI-1 inhibitor TM5275 effectively blocked cell proliferation of ovarian cancer cells that highly express PAI-1. Together these results suggest that PAI-1 promotes cell growth in ovarian cancer. Interestingly, expression of PAI-1 was increased in ovarian clear cell carcinoma compared with that in serous tumors. Our results suggest that PAI-1 inhibition promotes cell cycle arrest and apoptosis in ovarian cancer and that PAI-1 inhibitors potentially represent a novel class of anti-tumor agents.
    Cancer biology & therapy 01/2015;
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    ABSTRACT: Abstract The androgen receptor (AR) is central to the initiation and progression of prostate cancer, even after castration. There has been some success in therapies targeting AR signaling which have been shown to extend survival in men with castration-resistant prostate cancer (CRPC). Enzalutamide is a potent AR antagonist that was initially approved in 2012 for men with CRPC who had previously failed chemotherapy treatment with docetaxel. Herein, we reviewed two key manuscripts that have recently appeared in the New England Journal of Medicine regarding enzalutamide. The PREVAIL Phase 3 trial was designed to evaluate enzalutamide before chemotherapy in men with CRPC. The study illustrated that 65% of patients receiving enzalutamide had radiographic-progression free survival. There was a significant risk reduction of radiographic progression or death, compared with the placebo group. The enzalutamide group's median overall survival was 32.4 months vs. 30.2 months in the placebo group.
    Cancer biology & therapy 01/2015;
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    ABSTRACT: Abstract Several microRNAs (miRNA) have been implicated in H. pylori related gastric cancer (GC). However, the molecular mechanism of miRNAs in gastric cancer has not been fully understood. In this study, we reported that miR-101 is significantly down-regulated in H. pylori positive tissues and cells and in tumor tissues with important functional consequences. Ectopic expression of miR-101 dramatically suppressed cell proliferation and colony formation by inducing G1-phase cell-cycle arrest. We found that miR-101 strongly reduced the expression of SOCS2 oncogene in GC cells. Similar to the restoring miR-26 expression, SOCS2 down-regulation inhibited cell growth and cell-cycle progression, whereas SOCS2 over-expression rescued the suppressive effect of miR-101. Mechanistic investigations revealed that miR-101 suppressed the expression of c-myc, CDK2, CDK4, CDK6, CCND2, CCND3, and CCNE2, while promoted tumor suppressor p14, p16, p21 and p27 expression. In clinical specimens, SOCS2 was over-expressed in tumors and H. pylori positive tissues and its mRNA levels were inversely correlated with miR-101 expression. Taken together, our results indicated that miR-101 functions as a growth-suppressive miRNA in H. pylori related GC, and that its suppressive effects are mediated mainly by repressing SOCS2 expression.
    Cancer biology & therapy 01/2015;
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    ABSTRACT: Abstract Multiple myeloma (MM), a plasma cell malignancy, remains incurable despite the development of new therapies. Curcumin anti-tumor effects were previously characterized in multiple myeloma, however only few MM cell lines were included in these studies. Since myeloma is a heterogeneous disease it is important to address the impact of myeloma molecular heterogeneity in curcumin cell death induction. In the present study, a large panel of human myeloma cell lines (HMCLs) (n = 29), representing the main molecular MM subgroups, was screened for curcumin sensitivity. We observed that curcumin cell death induction was heterogeneous, of note 16 HMCLs were highly sensitive to curcumin (LD50 < 20.5μM), 6 HMCLs exhibited intermediate LD50 values (20.5μM ≤ LD50 < 32.2μM) and only 7 HMCLs were weakly sensitive (35 < LD50 < 56μM). Cell lines harboring the t(11;14) translocation were less sensitive (median LD50 32.9μM) than non-t(11;14) (median LD50 17.9μM), which included poor prognosis t(4;14) and t(14;16) cells. Interestingly, curcumin sensitivity was not dependent on TP53 status. For the first time we showed that primary myeloma cells were also sensitive, even those displaying del(17p), another poor prognosis factor. We also unravel the contribution of anti-apoptotic Bcl-2 family molecules in curcumin response. We found that down-regulation of Mcl-1, an essential MM survival factor, was associated with curcumin-induced cell death and its knockdown sensitized myeloma cells to curcumin, highlighting Mcl-1 as an important target for curcumin-induced apoptosis. Altogether, these results support clinical trials including curcumin in association with standard therapy.
    Cancer biology & therapy 12/2014;
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    ABSTRACT: Abstract SCLIP, a microtubule-destabilizing phosphoprotein, is known to be involved in the development of the central nervous system (CNS). It has been well established that there are notable parallels between normal development and tumorigenesis, especially in glioma. However, no studies have examined the significance of SCLIP in gliomagenesis. To address this, we investigated the expression of SCLIP and its roles in the development of gliomas. Notably, we found that SCLIP was highly expressed in various grades of glioma samples, as compared with normal brain tissues. Overexpression of SCLIP dramatically stimulated tumor cell migration and invasion as well as proliferation and downregulation of SCLIP showed opposite effects, establishing an important oncogenic role for this gene. Furthermore, we revealed that STAT3 was required to maintain SCLIP stability, suggesting that overexpression of STAT3 may be a critical step to facilitate microtubule dynamics and subsequently promotes migration and invasion of glioma cells. Taken together, our findings demonstrate that SCLIP plays an important role in glioma pathology, and may represent a novel therapeutic strategy against human glioma.
    Cancer biology & therapy 12/2014;
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    ABSTRACT: ABSTRACT Gemcitabine based treatment is currently a standard first line treatment for patients with advanced pancreatic cancer, however overall survival remains poor, and few options are available for patients that fail gemcitabine based therapy. To identify potential molecular targets in gemcitabine refractory pancreatic cancer, we developed a series of gemcitabine resistant (GR) cell lines. Initial drug exposure selected for an early resistant phenotype that was independent of drug metabolic pathways. Prolonged drug selection pressure after 16 weeks, led to an induction of cytidine deaminase (CDA) and enhanced drug detoxification. Cross resistance profiles demonstrate approximately 100-fold cross resistance to pyrimidine nucleoside cytarabine, but no resistance to the same in class agents, azacytidine and decitabine. GR cell lines demonstrated a dose dependent collateral hypersensitivity to class I and II histone deacetylase (HDAC) inhibitors and decreased expression of three different global heterochromatin marks, as detected by H4K20me3, H3K9me3 and H3K27me3. Cell morphology of the drug resistant cell lines demonstrated a fibroblastic type appearance with loss of cell-cell junctions and an altered microarray expression pattern, using Gene Ontology (GO) annotation, consistent with progression to an invasive phenotype. Of particular note, the gemcitabine resistant cell lines displayed up to a 15 fold increase in invasive potential that directly correlates with the level of gemcitabine resistance. These findings suggest a mechanistic relationship between chemoresistance and metastatic potential in pancreatic carcinoma and provide evidence for molecular pathways that may be exploited to develop therapeutic strategies for refractory pancreatic cancer.
    Cancer biology & therapy 12/2014;
  • Cancer biology & therapy 12/2014;
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    ABSTRACT: Metastatic colon cancer has a 5-year survival of less than 10% despite the use of aggressive chemotherapeutic regimens. As signaling from epidermal growth factor receptor (EGFR) is often enhanced and epigenetic regulation is often altered in colon cancer, it is desirable to enhance the efficacy of EGFR-directed therapy by co-targeting an epigenetic pathway. We showed that the histone methyltransferase EZH2, which catalyzes methylation of histone H3 lysine 27 (H3K27), was upregulated in colon cancers in The Cancer Genome Atlas (TCGA) database. Since co-inhibition of both EGFR and EZH2 has not been studied in colon cancer, we examined the effects of co-inhibition of EGFR and EZH2 on 2 colon cancer cell lines, HT-29 and HCT-15. Co-inhibition of EZH2 and EGFR with the small molecules UNC1999 and gefitinib, led to a significant decrease in cell number and increased apoptosis compared to inhibition of either pathway alone, and similar results were noted after EZH2 shRNA knockdown. Moreover, co-inhibition of EZH2 and EGFR also significantly induced autophagy, indicating that autophagy may play a role in the observed synergy. Together, these findings suggest that inhibition of both EZH2 and EGFR serves as an effective method to increase the efficacy of EGFR inhibitors in suppressing colon cancer cells.
    Cancer biology & therapy 12/2014; 15(12):1677-87.
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    ABSTRACT: Mcl-1, a pro-survival member of the Bcl-2 protein family, is an attractive target for cancer therapy. We have recently identified the natural product marinopyrrole A (maritoclax) as a novel small molecule Mcl-1 inhibitor. Here, we describe the structure-activity relationship study of pyoluteorin derivatives based on maritoclax. To date, we synthesized over 30 derivatives of maritoclax and evaluated their inhibitory actions and cytotoxicity toward Mcl-1-dependent cell lines. As a result, several functional groups were identified in the pyoluteorin motif that significantly potentiate biological activity. A number of such derivatives, KS04 and KS18, interacted with Mcl-1 in a conserved fashion according to NMR spectroscopy and molecular modeling. KS04 and KS18 induced apoptosis selectively in Mcl-1-dependent but not Bcl-2-dependent K562 cells through selective Mcl-1 down-regulation, and synergistically enhanced apoptosis in combination with ABT-737. Moreover, the intraperitoneal administration of KS18 (10 mg/kg/d) and ABT-737 (20 mg/kg/d) significantly suppressed the growth of ABT-737-resistant HL-60 xenografts in nude mice without apparent toxicity. Overall, we identified the pharmacophore of pyoluteorin derivatives that act as potent and promising Mcl-1 antagonists against Mcl-1-dependent hematological cancers.
    Cancer biology & therapy 12/2014; 15(12):1688-99.
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    ABSTRACT: Checkpoint kinase 2 (Chk2) has been implicated in DNA damage signaling. By using BJ human fibroblasts, HCT116 colorectal cancer cells and HeLa cervical cancer cells, we further detailed phosphorylation kinetics of Chk2 under treatment with neocarcinostatin (NCS) or doxorubicin (Dox). After NCS treatment, phosphorylation of Chk2 Thr68 occurs in 3 min, followed by phosphorylation of Ser19 and Ser33/35. In ATM deficient fibroblasts, NCS does not induce phosphorylation of NBS1 Ser343 and Chk2 Ser19 and Ser33/35, however Chk2 Thr68 is still phosphorylated, indicating that ATM is essential for phosphorylation of these residues when treated with NCS. By using Chk2-deficient HCT116 cells re-expressing phospho-mutant Chk2 (T68A), we found that inhibition of Thr68 phosphorylation enhances Ser19 phosphorylation in NCS treated cells. Interestingly, in contrast to NCS, Dox does not induce Ser33/35 phosphorylation in HeLa and HCT116 cells. Phosphorylation of Thr68 is sustained until 3 to 4 hours, and phosphorylation of Ser19 occurs 70 to 80 min after Dox treatment. These results demonstrate that Chk2 s involved in the early stages of DNA damage response. Differential phosphorylation kinetics of these residues suggests that DNA damage determines intermolecular and intramolecular interaction of Chk2, which may regulate phosphorylation.
    Cancer biology & therapy 12/2014; 15(12):1700-4.
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    ABSTRACT: Abstract Carcinogenesis is etiologically associated with somatic mutations of critical genes. Recently, a number of somatic mutations and key molecules have been found to be involved in functional networks affecting cancer progression. Suitable animal models are required to validate cancer-promoting or -inhibiting capacities of these mutants and molecules. Sleeping Beauty transposon system consists of a transposon that carries gene(s) of interest and a transposase that recognizes, excises, and reinserts genes in given location of the genome. It can create both gain-of-function and loss-of-function mutations, thus being frequently chosen to investigate the etiological mechanisms and gene therapy for cancers in animal models. In this review, we summarized current advances of Sleeping Beauty transposon system in revealing molecular mechanism of cancers and improving gene therapy. Understanding molecular mechanisms by which driver mutations contribute to carcinogenesis and metastasis may pave the way for the development of innovative prophylactic and therapeutic strategies against malignant diseases.
    Cancer biology & therapy 12/2014;
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    ABSTRACT: Abstract Cancer cachexia is a progressive metabolic disorder that results in depletion of adipose tissue and skeletal muscle. A growing body of literature suggests that maintaining adipose tissue mass in cachexia may improve quality-of-life and survival outcomes. Studies of lipid metabolism in cachexia, however, have generally focused on later stages of the disorder when severe loss of adipose tissue has already occurred. Here, we investigated lipid metabolism in adipose, liver and muscle tissues during early stage cachexia - before severe fat loss - in the colon-26 murine model of cachexia. White adipose tissue mass in cachectic mice was moderately reduced (34 - 42%) and weight loss was less than 10% of initial body weight in this study of early cachexia. In white adipose depots of cachectic mice, we found evidence of enhanced protein kinase A - activated lipolysis which coincided with elevated total energy expenditure and increased expression of markers of brown (but not white) adipose tissue thermogenesis and the acute phase response. Total lipids in liver and muscle were unchanged in early cachexia while markers of fatty oxidation were increased. Many of these initial metabolic responses contrast with reports of lipid metabolism in later stages of cachexia. Our observations suggest intervention studies to preserve fat mass in cachexia should be tailored to the stage of cachexia. Our observations also highlight a need for studies that delineate the contribution of cachexia stage and animal model to altered lipid metabolism in cancer cachexia and identify those that most closely mimic the human condition.
    Cancer biology & therapy 12/2014;
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    ABSTRACT: The goal of adjuvant hormonal therapy for breast cancer is to prevent recurrence by eradicating micrometastatic disease. Recent studies have shown that the use of aromatase inhibitors (AIs) as adjuvant therapy improves outcomes for postmenopausal women with estrogen receptor (ER)-positive breast cancer compared to adjuvant endocrine therapy with tamoxifen alone. The research question has been raised whether AIs would have similar improvements in disease-free survival (DFS) in premenopausal women with ER-positive breast cancer. Combining 2 phase 3 clinical trials (n = 4,690), Pagani and colleagues randomized premenopausal women with ER-positive early breast cancer to exemestane plus ovarian suppression or tamoxifen plus ovarian suppression for a period of 5 y. After a median follow-up of 68 months, DFS was 91.1% in the AI group and 87.3% in the tamoxifen group. In premenopausal women with hormone-receptor-positive early breast cancer, adjuvant treatment with exemestane plus ovarian suppression, as compared with tamoxifen plus ovarian suppression, significantly reduced recurrence.
    Cancer biology & therapy 12/2014; 15(12):1586-7.
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    ABSTRACT: Our previous studies have showed that Gli2 played a predominant role in proliferation and apoptosis resistance to TRAIL in hepatoma cells. The purpose of this study was to explore whether Gli2 silencing enhances efficiency of TRAIL for hepatoma in vivo. SMMC-7721-shRNA cells were implanted subcutaneously into nude mices and TRAIL was injected into the peritoneal space. TUNEL assay was used to detect apoptosis of tumor cells. The expression of Gli2, c-FLIPL, c-FLIPS, and Bcl-2 protein was determined by immunohistochemistry, respectively. Apoptosis and the level of caspases proteins in SMMC-7721 and HepG2 cells were detected by Flow cytometry and Western blot. Transcriptional activity of c-FLIP induced by Gli2 was measured by luciferase reporter gene assay. The results showed that lower volumes and weights of tumor were found in mice xenografted with SMMC-7721-shRNA cells as compared with control cells in the presence of TRAIL (P < 0.05). TUNEL assay showed significantly higher apoptosis index (AI) in the SMMC-7721-shRNA group than in the control groups (P < 0.05). There were remarkable positive correlations between Gli2 and c-FLIPL, c-FLIPS, Bcl-2 protein expression. Over-expression of c-FLIP or Bcl-2 in HepG2 cells attenuated TRAIL-induced apoptosis via suppression of caspase-8 or caspase-9 activity, respectively. Luciferase reporter gene assay found a regulatory sequence by which Gli2 activated transcription between -1007 to -244 in the c-FLIP promoter region. This study demonstrates that Gli2 showed regulatory activity on transcription of c-FLIP gene, and Gli2 silencing enhances TRAIL-induced apoptosis via down-regulation of c-FLIP and Bcl-2 in human hepatoma cells in vivo.
    Cancer biology & therapy 12/2014; 15(12):1667-76.
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    ABSTRACT: Abstract Reductions in both expression of the dystroglycan core protein and functional glycosylation of the alpha-dystroglycan (αDG) subunit have been reported in a number of cancers and may contribute to disease progression. In the case of prostate cancer, one mechanism that contributes to αDG hypoglycosylation is transcriptional down-regulation of LARGE2 (GYLTY1B), a glycosyltransferase that produces the functional (laminin-binding) glycan on αDG, but the mechanism(s) underlying reduction of LARGE2 mRNA remain unclear. Here, we show that αDG hypoglycosylation is associated with epithelial-to-mesenchymal transition (EMT)-like status. We examined immunoreactivity for both functionally-glycosylated αDG and E-cadherin by flow cytometry and the relative expression of ZEB1 mRNA and the αDG glycosyltransferase LARGE2 mRNA in prostate and other cancer cell lines by quantitative RT-PCR. To study the role of ZEB1 and other transcription factors in the regulation of LARGE2, we employed overexpression and knockdown approaches. Snail- or ZEB1-driven EMT caused αDG hypoglycosylation by repressing expression of the LARGE2 mRNA, with both ZEB1-dependent and -independent mechanisms contributing to Snail-mediated LARGE2 repression. To examine the direct regulation of LARGE2 by Snail and ZEB1 we employed luciferase reporter and chromatin immunoprecipitation assays. Snail and ZEB1 were found to bind directly to the LARGE2 promoter, specifically to E/Z-box clusters. Furthermore, analysis of gene expression profiles of clinical samples in The Cancer Genome Atlas reveals negative correlation of LARGE2 and ZEB1 expression in various cancers. Collectively, our results suggest that LARGE2 is negatively regulated by Snail and/or ZEB1, revealing a mechanistic basis for αDG hypoglycosylation during prostate cancer progression and metastasis.
    Cancer biology & therapy 12/2014;