[Show abstract][Hide abstract] ABSTRACT: Higher standardized uptake value (SUV) detected by 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) correlates with proliferation of primary breast cancer. The purpose of this study is to identify specific molecules upregulated in primary breast cancers with a high SUV and to examine their clinical significance.
We compared mRNA expression profiles between 14 tumors with low SUVs and 24 tumors with high SUVs by cDNA microarray. We identified centromere protein F (CENP-F) and CDC6 were upregulated in tumors with high SUVs. RT-PCR and immunohistochemical analyses were performed to validate these data. Clinical implication of CENP-F and CDC6 was examined for 253 archival breast cancers by the tissue microarray.
The relative ratios of CENP-F and CDC6 expression levels to beta-actin were confirmed to be significantly higher in high SUV tumors than in low SUV tumors (p = 0.027 and 0.025, respectively) by RT-PCR. In immunohistochemical analysis of 47 node-negative tumors, the CENP-F expression was significantly higher in the high SUV tumors (74%) than the low SUV tumors (45%) (p = 0.04), but membranous and cytoplasmic CDC6 expressions did not significantly differ between both groups (p = 0.9 each). By the tissue microarray, CENP-F (HR = 2.94) as well as tumor size (HR = 4.49), nodal positivity (HR = 4.1), and Ki67 (HR = 2.05) showed independent impact on the patients' prognosis.
High CENP-F expression, correlated with high SUV, was the prognostic indicators of primary breast cancer. Tumoral SUV levels may serve as a pretherapeutic indicator of aggressiveness of breast cancer.
[Show abstract][Hide abstract] ABSTRACT: To identify molecular signatures and establish a new diagnostic model for progressive oral squamous cell carcinoma (OSCC). Total RNAs were isolated from primary OSCCs from both node-positive and -negative patients and used in cDNA microarray analysis. To identify marker genes representing a malignant phenotype, their expression was further examined by quantitative reverse transcription-PCR (QRT-PCR) in 64 OSCC tissues. Using Fisher's linear discriminant analysis (LDA) fitted with a stepwise increment method, we created discriminatory predictor models. The stability of these models was examined using leave-one-out cross validation. Immunohistochemical analysis was performed. Among the 16,600 possible target cDNAs in the array analysis, 83 genes demonstrated significantly differential signals (>2-fold). We further identified 53 marker genes that can be implicated in the Yamamoto-Kohama's (YKs) mode of invasion for OSCCs (P < 0.06). Using LDA fitted with a stepwise increment method, we created four discriminatory predictor models based on 16- to 25-gene signatures which could best distinguish the five established grades of YKs mode of invasion. Leave-one out validation demonstrated that the stability of these models was 92-95%. For validation, we also examined an independent set of 13 primary OSCCs; the predictor models determined the invasion status from 77% to 100% (on average, 85%) fidelity with the pathological observations. TGM3 protein expression was markedly suppressed in highly invasive OSCCs. We reveal novel gene expression alterations during the progression of OSCC, and have constructed prediction models for the evaluation of the invasion status of these cancers.
Full-text · Article · Oct 2008 · Molecular Carcinogenesis
[Show abstract][Hide abstract] ABSTRACT: To identify differentially expressed genes and thereby detect potential molecular targets for future therapies directed against hepatocellular carcinoma (HCC).
To isolate differentially expressed genes between HCC and adjacent non-cancerous liver tissues, cDNA microarray and quantitative reverse transcriptase polymerase chain reaction analyses were performed. Gene knockdown experiments in HepG2 cells were also performed using small interfering RNAs (siRNAs). Proteins were detected by immunostaining, and cell proliferation was analysed using the MTT/WST-8 assay. Apoptosis and cell cycle analyses were performed using flow cytometry.
After an intensive screening for differentially expressed genes in HCC tissues, we isolated 23 upregulated genes in these lesions. Among these, we focused on the replication factor C4 (RFC4) gene. The expression of endogenous RFC4 proteins in HepG2 cells was found to be significantly reduced by RFC4-specific siRNA. This inhibition of RFC4 expression correlated with a decrease in cellular proliferation, increased levels of apoptosis and a sensitizing of the cells to the DNA-damaging chemotherapeutic agents, doxorubicin and camptothecin.
The replication factor C4 gene may be a novel target for developing cancer therapeutics, which can enhance the antitumour activity of chemotherapeutic agents that induce DNA damage.
No preview · Article · Jun 2008 · Liver international: official journal of the International Association for the Study of the Liver
[Show abstract][Hide abstract] ABSTRACT: To identify new target marker genes in renal cell carcinoma (RCC), we compared the gene expression profiles of clear cell RCC (cc-RCC) and normal kidney tissue using serial analysis of gene expression. Our results revealed that the transforming growth factor beta induced 68 kDa protein (TGF-betaI: beta ig-h3 (BIGH3), plasminogen activator inhibitor-1 (PAI-1) and transforming growth factor beta1 (TGF-beta1) genes are up-regulated in cc-RCC. To further assess the role of BIGH3 in RCC, we investigated the mRNA expression levels of BIGH3, TGFbeta1, PAI-1 and also of TGF-beta1 related genes in 53 RCC and 30 normal kidney tissues by quantitative real-time RT-PCR (QRT-PCR). We further determined the BIGH3 protein levels in 52 cc-RCC paraffin-embedded tissue samples by immunohistochemistry. BIGH3 mRNA was found to be highly overexpressed in cc-RCC compared with normal tissues with an average ratio of 27. The mRNA levels of TGF-beta1 and PAI-1 were also detected at significantly elevated levels in these cancers. Immunohistochemical analysis of BIGH3 also revealed strong staining in the majority of the cc-RCC samples. In addition, the up-regulation of BIGH3 and PAI-1 was found to correlate with the clinicopathological parameters associated with a poorer patient outcome, whereas TGF-beta1 expression was determined to be unrelated to cancer progression. Strong BIGH3 staining thus tended to be associated with a poor prognosis. BIGH3 was also induced in some RCC cell lines by TGF-beta1 stimulation and this correlated well with PAI-1 up-regulation, suggesting that these enhancements are regulated by a similar mechanism in these tumors.
No preview · Article · May 2008 · Oncology Reports
[Show abstract][Hide abstract] ABSTRACT: Using integrated 18F-fluorodeoxyglucose positron emission tomography/computed tomography fusion imaging (18F-FDG PET/CT), the clinical significance of 18F-FDG uptake was evaluated in patients with primary breast cancer.
Clinicopathological correlation with the level of maximum standardized uptake values (SUV) 60 min obtained from preoperative 18F-FDG PET/CT were examined in 152 patients with primary breast cancer. The prognostic impact of the level of SUV was explored using simulated prognosis derived from computed program Adjuvant! in 136 (89%) patients with invasive ductal carcinoma (IDC).
High SUV level was significantly correlated with tumor invasive size (< or = 2 cm) (P < 0.0001), higher score of nuclear grade (P < 0.0001), nuclear atypia (P < 0.0001) and mitosis counts (P < 0.0001), negative hormone receptor status (P = 0.001), high score of c-erbB-2 expression (P = 0.006), lymph node metastasis (P = 0.002), and IDC in comparison with invasive lobular carcinoma (P = 0.004). Multivariate analyses showed tumor invasive size, nuclear grade and estrogen receptor negativity were significantly correlated with SUV in primary breast cancer (P < 0.0001,< 0.0001, and < 0.012, respectively), and nuclear grade was significantly correlated with SUV in tumors of invasive size 2 cm or less (P < 0.0001). Tumors with high SUV (cutoff value 4.0) showed higher relapse and mortality rate compared to those with low SUV (P < 0.0001).
High uptake of 18F-FDG would be predictive of poor prognosis in patients with primary breast cancer, and aggressive features of cancer cells in patients with early breast cancer. 18F-FDG PET/CT could be a useful tool to pre-therapeutically predict biological characteristics and baseline risk of breast cancer.
Full-text · Article · May 2008 · Japanese Journal of Clinical Oncology
[Show abstract][Hide abstract] ABSTRACT: Human immunodeficiency virus type 1 (HIV-1) utilizes the macromolecular machinery of the infected host cell to produce progeny virus. The discovery of cellular factors that participate in HIV-1 replication pathways has provided further insight into the molecular basis of virus-host cell interactions. Here, we report that the suppressor of cytokine signaling 1 (SOCS1) is an inducible host factor during HIV-1 infection and regulates the late stages of the HIV-1 replication pathway. SOCS1 can directly bind to the matrix and nucleocapsid regions of the HIV-1 p55 Gag polyprotein and enhance its stability and trafficking, resulting in the efficient production of HIV-1 particles via an IFN signaling-independent mechanism. The depletion of SOCS1 by siRNA reduces both the targeted trafficking and assembly of HIV-1 Gag, resulting in its accumulation as perinuclear solid aggregates that are eventually subjected to lysosomal degradation. These results together indicate that SOCS1 is a crucial host factor that regulates the intracellular dynamism of HIV-1 Gag and could therefore be a potential new therapeutic target for AIDS and its related disorders.
Full-text · Article · Feb 2008 · Proceedings of the National Academy of Sciences
[Show abstract][Hide abstract] ABSTRACT: The molecular mechanisms of growth suppression by retinoic acid (RA) were examined. Our results suggest that the cytostatic effects of RA could be mediated by the activation of endogenous CBR3 gene in oral squamous cell carcinomas (OSCCs), and the expression is a potential marker for oral malignancy.
Full-text · Article · Feb 2008 · The Open Dentistry Journal
[Show abstract][Hide abstract] ABSTRACT: The Ets family of transcription factors is implicated in malignant transformation and tumor progression, including invasion, metastasis and neo-angiogenesis. In the present study, we found that the Fli-1 gene, a member of the Ets family, was highly expressed in several breast cancer cell lines (MDA-MB231, MDA-MB436, BT-549 and HCC1395). To investigate the functional roles of Fli-1 in breast cancer malignancy, we introduced an expression plasmid containing full-length Fli-1 cDNA into MCF7 breast cancer cells in which endogenous expression of Fli-1 was barely detectable.Overexpression of Fli-1 in MCF7 cells led to inhibition of apoptosis induced by serum depletion or ultraviolet irradiation, although it did not affect cell growth rate in liquid media, colony formation in soft agar or the in vitro invasion capacity of the cells. Expression of Fli-1 and antiapoptotic bcl-2 was coordinately upregulated by serum depletion in MCF7 cells, and the upregulation was inhibited by treatment of the cells with a c-Jun-NH(2)-terminal kinase-specific inhibitor. Furthermore, expression of the bcl-2 gene and protein was enhanced in Fli-1-overexpressing MCF7 cells compared with mock-transfected cells. In addition, human bcl-2 promoter activity was transactivated by Fli-1. These results suggest that Fli-1 contributes to the malignancy of human breast cancer by inhibiting apoptosis through upregulated expression of the bcl-2 gene.
[Show abstract][Hide abstract] ABSTRACT: The expression of amino acid transporter (AT) mRNAs including A system (ATA1/SNAT1/SLC38A1, ATA2/SNAT2/SLC38A2 and ATA3/SNAT3/SLC38A4), L system (LAT1/SLC7A5 and LAT2/SLC7A8), and y+ (CAT2/SLC7A2) genes, were compared among hepatocellular carcinoma (HCC) and non-cancerous liver cells. Among them the ATA1 mRNA expression was significantly elevated in all HCC cell lines (HepG2, HLF, HuH7 and JHH4) examined compared with normal liver tissue. We further discovered that the expression of ATA1 mRNA was significantly activated in HCC tissues and also elevated in pre-malignant cirrhotic livers from HCC patients, compared with normal livers from non-HCC patients. The ATA1 protein was extensively accumulated in the cytoplasm of pre-malignant liver and most HCCs, while being weak or undetectably low in normal liver tissues. SiRNA-mediated suppression of endogenous ATA1 lowered the viability of HepG2 cells. Thus, the activation of ATA1 confers growth and survival advantages in pre-malignant and malignant liver lesions.
Preview · Article · Aug 2007 · International Journal of Oncology
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study is to generate a classifier for oral squamous cell carcinoma (OSCC) and leukoplakias (LPs), and evaluate its diagnostic potential. In order to identify marker gene candidates, differential gene expression between LPs and OSCCs were examined by cDNA microarray. The expression of 118 marker gene candidates was further evaluated by quantitative reverse transcription-PCR (QRT-PCR) analyses of 27 OSCC and 19 LP tissues. We identified 12 up-regulated and 15 down-regulated marker genes in OSCCs compared to LPs. Using Fisher's linear discriminant analysis (LDA), we demonstrated that 11-gene predictors among this novel marker set could best distinguish OSCCs from LPs (>97% accuracy), whereas a further seven of these gene predictors could be utilized to distinguish higher grade (higher than moderate) from lower grade (lower than mild) dysplasias (>95% accuracy). These predictor gene sets provide multigene classifiers for the diagnosis of pre-cancerous to cancerous transition of oral malignancy.
[Show abstract][Hide abstract] ABSTRACT: We have previously reported that the endoplasmic reticulum (ER) stress-regulated transmembrane transcription factor 6 alpha (ATF6alpha) is implicated in the pathogenesis of hepatocellular carcinomas (HCCs). In order to further identify genes that are regulated by ATF6alpha, the global gene expression profiles of the ATF6alpha-transfected and untransfected HCC cell line, HLF, were analyzed. These results were then compared with the differential gene expression patterns of poorly differentiated HCC and control non-tumorous liver tissue. Our findings demonstrate that at least 18 genes are specifically upregulated by ATF6alpha, while another UPR mediator, XBP1 or ER-stress inducer, thapsigargin could partially stimulate or even repress some of them in HCC cells. Moreover, six of these identified genes contain potential ER stress-responsive elements and/or unfolded protein response elements in their 5' regulatory regions.
[Show abstract][Hide abstract] ABSTRACT: We have previously reported that significantly higher levels of Keratin 14 (Ker-14) was observed in oral squamous cell carcinoma (OSCC) and severely dysplastic tissues, whereas this expression was reversed in hyperplasia and in mild to moderate dysplasia. In this study, the mechanism of Keratin 14 activation in oral squamous cell carcinoma (OSCC) cell lines (HSC-2, HSC-3 and Ca9-22) was investigated. Reporter analysis demonstrated that an upstream region (-1759/-1629) accounted for efficient promoter activity. Furthermore, electromobility sift and supershift assay demonstrated that interactions of the SP-1/SP-3 complex at the elements resided in -1737/-1702 and -1680/-1652 and may be essential for this activation in OSCC cells.
No preview · Article · Jan 2006 · Oncology Reports
[Show abstract][Hide abstract] ABSTRACT: To identify differentially expressed genes during the development of oral malignancy, differential display, northern blotting, reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemical analyses were undertaken using oral squamous cell carcinoma (OSCC) and leukoplakia tissues. Significantly higher levels of keratin (Ker)-14 and -17 mRNAs, combined with lower levels of Ker-4, Ker-13 and transglutaminase 3 (TG-3) transcripts, were observed in OSCC and severely dysplastic tissues, whereas this expression profile was reversed in hyperplasia and in mild to moderate dysplasia. The expression of Ker-4 and Ker-13 was elevated in density-arrested OSCC cell lines (Ca9-22, HSC-2, -3 and -4) but the expression of Ker-17 mRNA was elevated in these cells, regardless of the growth conditions. In addition, Ker-4 and Ker-13 proteins were predominantly expressed in moderate dysplasia and hyperplasia, whereas Ker-17 was markedly expressed in OSCC tissues. The expression patterns of these genes could therefore be an important determinant of the manifestation of oral malignancy.
[Show abstract][Hide abstract] ABSTRACT: We applied serial analysis of gene expression (SAGE) to the mouse testis to reveal the global gene expression profile and to identify senescence-dependent changes in that profile. A total of 61,929 SAGE tags, including 19,323 unique tags, were obtained from 3- and 29-month-old BDF1 mice and 14-month-old SAMP1 mice. Genes highly expressed in the testis included those associated with spermatogenesis, protein metabolism, energy metabolism, growth and differentiation, and signal transduction. Testes from old mice of both strains appeared atrophied. Morphological examination of aged testes revealed extremely thin seminiferous epithelia and significantly decreased numbers of spermatids and spermatocytes. Despite the physical deterioration, no gross changes in the gene expression profile were apparent in the testes of old BDF1 mice. However, in 14-month-old SAMP1 mice, protamine 2 gene transcription was approximately 50% lower than in BDF1 mice. This reduction may be associated with the oligozoospermia and early decline in reproductive performance of SAMP1 mice. Our SAGE results are the first quantitative gene expression profile of the mouse testis and provide a reliable transcriptome reference for this organ.
No preview · Article · Jul 2004 · Mammalian Genome
[Show abstract][Hide abstract] ABSTRACT: The expression of Galectin-1 (Gal-1) mRNA was activated in primary hepatocellular carcinomas (HCCs) compared to matched non-tumorous liver tissues. To elucidate the mechanism of Gal-1 activation in HCC cells, DNA methylation encompassing the transcriptional start site (-165/+151) was examined. Among 12 CpG dinucleotides on both DNA strands, those at positions -116, -109, -52, -41, -36, +35 and +43 were preferentially methylated in non-tumorous liver tissue, while hypomethylated in the matched HCC tissue. Transient transfection of a series of deleted GAL-1 promoters revealed that both an upstream (-57/-31) and a downstream (+10/+57) elements accounted for efficient promoter activity. Electrophoretic mobility shift assay of the upstream element (-63/-30) using nuclear extracts from three HCC cell lines (HLF, HuH7 and HepG2) and normal liver cells revealed at least two complexes (alpha and (beta) interacted with the upstream element in all of the nuclear extracts. Competition experiments revealed that the complex beta preferentially attached to the upstream element harboring unmethylated CpGs. On the other hand, at least three complexes (I, II and III) interacted with the downstream element in all of the nuclear extracts. Competition experiments revealed that complex I specifically attached to the downstream element harboring unmethylated CpG at +35. Furthermore, a DNase I protection assay revealed that a methylation-associated conformational alteration occurred near the CpG site at +35 in HLF cells. Thus, the specific interaction of methylation-sensitive factors to the upstream and downstream elements may be essential for the activation of the Gal-1 gene in HCC cells.
No preview · Article · Jan 2004 · International Journal of Oncology
[Show abstract][Hide abstract] ABSTRACT: Ihara epileptic rat (IER) is an animal model of temporal lobe epilepsy (TLE) with genetically programmed microdysgenesis in the hippocampal formation. The neuronal microdysgenesis is thought to be a cause for recurrent spontaneous seizures. To identify differentially expressed genes in the hippocampus of IER in comparison to control Wistar rat, we performed serial analysis of gene expression (SAGE). As many as 21 differentially expressed genes were identified.
No preview · Article · Nov 2003 · Molecular Brain Research
[Show abstract][Hide abstract] ABSTRACT: We identified the glucose-regulated protein (grp) 78 as a transformation-associated gene in hepatocellular carcinoma (HCC). Grp78 is a molecular chaperone involved in the unfolded protein response, the expression of which can be regulated by the transcription factors ATF6 and XBP1. Thus, we investigated the regulatory mechanisms of the grp78 gene in liver malignancy.
Expression of grp78, ATF6 and XBP1 was examined by Northern blot, RT-PCR, immunoblot and immunohistochemical analyses. A reporter assay of the grp78 promoter was also performed.
Elevation of grp78 and ATF6 mRNAs and the splicing of XBP1 mRNA, resulting in the activation of XBP1 product, occurred in HCC tissues with increased histological grading. Higher accumulation of the grp78 product in the cytoplasm, concomitantly with marked nuclear localization of the activated ATF6 product (p50ATF6), was observed in moderately to poorly differentiated HCC tissues. Cooperation between the distal DNA segment and the proximal endoplasmic reticulum stress response elements was essential for maximum transcription of the grp78 promoter in HCC cells.
The endoplasmic reticulum stress pathway mediated by ATF6 and by IRE1-XBP1 systems seems essential for the transformation-associated expression of the grp78 gene in HCCs.
No preview · Article · Jun 2003 · Journal of Hepatology
[Show abstract][Hide abstract] ABSTRACT: The gene expression patterns of primordial germ cells (PGCs) and embryonic stem cells were analyzed by a modified serial analysis of gene expression. During the process, we cloned a novel gene, PGC7, which was preferentially expressed in PGCs. Immunohistochemical analysis revealed that PGC7 was specifically expressed in early pre-implantation embryos, PGCs and oocytes. These results suggest that PGC7 might play an important role in the development of PGCs and oocytes.
Full-text · Article · May 2002 · Mechanisms of Development
[Show abstract][Hide abstract] ABSTRACT: Anchorage independence is an important hallmark of the transformation that correlates with tumorigenicity. We have isolated a variant clone of HT1080 human fibrosarcoma cells (cl-2) that is specifically defective in anchorage-independent growth. Interestingly, 10(-7) M dexamethasone (DEX) substantially rescued the anchorage-independent growth of cl-2 cells in semisolid culture. DEX also promoted the anchorage-independent growth of parental HT1080 cells. However, the agent had no effect on the anchorage-dependent growth of cl-2 and parental cells in ordinary liquid culture. Cell cycle analysis demonstrated that the population of G0/G1 cells increased, whereas that of S and G2/M cells decreased in growth-arrested cl-2 cells in suspension culture. However, such an effect of anchorage loss on cell cycle progression was alleviated by adding 10(-7) M DEX. In cl-2 cells in semisolid culture, DEX suppressed the expression of P27Kip1, whereas it stimulated the expression of cyclin A and hyperphosphorylated retinoblastoma (Rb) proteins. On the other hand, DEX had no effect on cyclin D1 and P21Cap1 expression. These effects of DEX, except for the suppression of P27Kip1, were blocked by an antimicrofilament drug, cytochalasin D. Our results suggest that the stimulation of anchorage-independent growth by DEX involves at least two regulatory mechanisms, i.e., one that leads to the suppression of P27Kip1 protein without requiring cytoskeletal integrity, and another that requires cytoskeletal integrity, leading to stimulation of cyclin A and hyperphosphorylation of Rb protein.
No preview · Article · Mar 2002 · In Vitro Cellular & Developmental Biology - Animal
[Show abstract][Hide abstract] ABSTRACT: The B cell lymphoma WEHI231 has been used as a model for studying clonal deletion of B cells on the basis of its ability to undergo growth arrest and apoptosis by B cell antigen receptor (BCR) cross-linking. To comprehensively analyze the genes involved in BCR-mediated apoptosis, we applied the technique of serial analysis of gene expression (SAGE) to WEHI231. Comparison of expression patterns revealed that BCR cross-linking caused coordinate changes in the expression of genes involved in polyamine metabolism. Polyamines are ubiquitous compounds required for cell proliferation and homeostasis. The coordinate expression of the polyamine-related genes was confirmed by semiquantitative reverse transcriptase–polymerase chain reaction analysis. During apoptosis, the genes involved in polyamine biosynthesis were downregulated, whereas those involved in polyamine catabolism were upregulated, suggesting that intracellular polyamines play a role in BCR-mediated apoptosis. Levels of intracellular putrescine, spermidine, and spermine were reduced after BCR cross-linking. These effects were prevented by concurrent CD40 stimulation, which blocked BCR-mediated apoptosis. Furthermore, addition of spermine could repress the BCR-mediated apoptosis by attenuating the mitochondrial membrane potential (Δψm) loss and activation of caspase-7 induced by BCR signaling. These findings strongly suggest that polyamine regulation is involved in apoptosis during B cell clonal deletion.
No preview · Article · May 2001 · Experimental Cell Research