Global expression changes of constitutive and hormonally regulated genes during endometrial neoplastic transformation

TRIM29 hypermethylation drives esophageal cancer progression via suppression of ZNF750

Esophageal cancer (ESCA) is the seventh most frequent and deadly neoplasm. Due to the lack of early diagnosis and high invasion/metastasis, the prognosis of ESCA remains very poor. Herein, we identify skin-related signatures as the most deficient signatures in invasive ESCA, which are regulated by the transcription factor ZNF750. Of note, we find that TRIM29 level strongly correlated with the expression of many genes in the skin-related signatures, including ZNF750. TRIM29 is significantly down-regulated due to hypermethylation of its promoter in both ESCA and precancerous lesions compared to normal tissues. Low TRIM29 expression and high methylation levels of its promoter are associated with malignant progression and poor clinical outcomes in ESCA patients. Functionally, TRIM29 overexpression markedly hinders proliferation, migration, invasion, and epithelial-mesenchymal transition of esophageal cancer cells, whereas opposing results are observed when TRIM29 is silenced in vitro. In addition, TRIM29 inhibits metastasis in vivo. Mechanistically, TRIM29 downregulation suppresses the expression of the tumor suppressor ZNF750 by activating the STAT3 signaling pathway. Overall, our study demonstrates that TRIM29 expression and its promoter methylation status could be potential early diagnostic and prognostic markers. It highlights the role of the TRIM29-ZNF750 signaling axis in modulating tumorigenesis and metastasis of esophageal cancer.

KLF9 suppresses cell growth and induces apoptosis via the AR pathway in androgen-dependent prostate cancer cells

Kruppel-like factors (KLFs) play an important role in many biological processes including cell proliferation, differentiation and development. Our study showed that the level of KLF9 is lower in PCa cell lines compared to a benign prostate cell line; the androgen-independent cell line PC3 expresses significantly lower KLF9 than the androgen-dependent cell line, LNCaP. Forced overexpression of KLF9 suppressed cell growth, colony formation, and induced cell apoptosis in LNCaP cells. We also found that KLF9 expression was induced in response to apoptosis caused by flutamide, and further addition of dihydrotestosterone antagonized the action of flutamide and significantly decreased KLF9 expression. Furthermore, activation of the androgen receptor (AR) was inhibited by the overexpression of KLF9. Our research shows that KLF9 is lower in androgen-independent cell lines than in androgen-dependent cell lines; Overexpression of KLF9 dramatically suppresses the proliferation, anchorage-independent growth, and induces apoptosis in androgen-dependent cells; KLF9 inhibition on prostate cancer cell growth may be acting through the AR pathway. Our results therefore suggest that KLF9 may play a significant role in the transition from androgen-dependent to androgen-independent prostate cancer and is a potential target of prevention and therapy.

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KLF9 is lower in androgen-independent cell lines than in androgen-dependent cell lines.

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Overexpression of KLF9 suppresses the proliferation and induces apoptosis in androgen-dependent cells.

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KLF9 inhibition on androgen-dependent Pca growth may be associated with the inhibition of AR pathway.

The Tumor Suppressor Role of the Ras Association Domain Family 10

The Ras association domain family 10(RASSF10), a tumor suppressor gene, is located on human chromosome 11p15.2, which is one of the members homologous to other N-terminal RASSF families obtained through structural prediction. RASSF10 plays an important role in inhibiting proliferation, invasion, and migration, inducing apoptosis, making cancer cells sensitive to docetaxel, and capturing G2/M phase. Some studies have found that RASSF10 may inhibit the occurrence and development of tumors by regulating Wnt/β-catenin, P53, and MMP2. Methylation of tumor suppressor gene promoter is a key factor in the development and progression of many tumors. Various methylation detection methods confirmed that the methylation and downregulation of RASSF10 often occur in various tumors, such as gastric cancer, lung cancer, colon cancer, breast cancer, and leukemia. The status of RASSF10 methylation is positively correlated with tumor size, tumor type, and TNM stage. RASSF10 methylation can be used as a prognostic factor for overall survival and disease-free survival, and is also a sign of tumor diagnosis and sensitivity to docetaxel chemotherapy. In this review, we mainly elucidate the acknowledged structure and progress in the verified functions of RASSF10 and the probably relevant signaling pathways.

Prognostic Role of Krüppel-Like Factors 5, 9, and 11 in Endometrial Endometrioid Cancer

BACKGROUND AND OBJECTIVE

Krüppel-like factors (KLFs) are transcription factors with the ability to mediate cross-talk with signaling pathways involved in cell proliferation control, apoptosis, migration, and differentiation. They also appear to influence steroid hormone signaling through transcriptional networks involving steroid hormone receptors and members of the nuclear receptor family of transcription factors. Our study aims to evaluate the potential prognostic role of KLF5, KLF9, and KLF11 in endometrial cancer, and their correlation with hormonal receptor status and cellular proliferation.

MATERIALS AND METHODS

Retrospective observational study on cases of endometrioid endometrial adenocarcinoma collected in the period January 2000-December 2011 at the University of Udine. Formalin-fixed, paraffin-embedded tissue samples were all submitted to tissue microarray immunohistochemical study. A survival analysis was performed.

RESULTS

One hundred forty seven patients were included in the study with a mean age at surgery of 65.6 years (±10.2). 80.3% of endometrial malignancies were classified as stage FIGO I (118/147). Radiation therapy and chemotherapy were administered in 62.3% (91/146) and 6.2% (9/145) of patients respectively. Five-year overall survival and disease-free survival resulted 85.4% (95% CI, 79.8-91.4%) and 79.4% (95% CI, 73.0-86.4%) respectively. A high Ki-67, cytoplasmatic KLF5 (HR 4.72, CI.95 1.61-13.89, p < 0.05), and nuclear KLF11 (HR 3.04, CI.95 0.99-9.36, p = 0.053) scores correlated with a shorter overall survival. In addition, a high nuclear KLF11 (HR 2.59, CI.95 1.13-5.95, p < 0.05) score correlated with a shorter disease-free survival.

CONCLUSIONS

In patients affected by endometrioid endometrial carcinoma, higher staining levels of KLF5 and KLF11 correlated with a poorer prognosis. However, further studies are required in order to better clarify the role of KLFs in the natural history of endometrial cancer.

TRIM29 facilitates the epithelial-to-mesenchymal transition and the progression of colorectal cancer via the activation of the Wnt/β-catenin signaling pathway

Background

Tripartite Motif 29 (TRIM29) has been newly identified as being implicated in cancer progression. However, the biological role and molecular mechanism of TRIM29 in the invasion and metastasis of colorectal cancer (CRC) remain to be determined.

Methods

The expression levels of TRIM29 and β-catenin in CRC patient specimens were detected by immunohistochemistry. Recombinant lentivirus vectors containing the TRIM29 gene and its small hairpin interfering RNAs were constructed and transduced into CRC cells. Wound-healing and Transwell assays were performed to evaluate the migration and invasion abilities of CRC cells in vitro. Hepatic metastasis models in nude mice were established to validate the function of TRIM29 in vivo. Moreover, the expressions of epithelial-to-mesenchymal transition (EMT)-associated proteins were detected by qRT-PCR and Western blotting in CRC cells. Finally, Western blotting, qRT-PCR, luciferase reporter assays, and immunofluorescence assays were used to explore the molecular mechanisms of TRIM29 in CRC progression.

Results

Increased TRIM29 expression positively correlated with lymph node metastasis and β-catenin expression in patient CRC tissues. Overexpression of TRIM29 promoted invasion and metastasis of CRC cells in vitro and in vivo by regulating EMT, whereas the knockdown of TRIM29 had the opposite effect. Further mechanistic studies suggest that TRIM29 can activate the Wnt/β-catenin signaling pathway via up-regulating CD44 expression in colorectal cancer.

Conclusions

TRIM29 induces EMT through activating the Wnt/β-catenin signaling pathway via up-regulating CD44 expression, thus promoting invasion and metastasis of CRC.

Identification of nasopharyngeal carcinoma metastasis-related biomarkers by iTRAQ combined with 2D-LC-MS/MS

To identify metastasis-related proteins in nasopharyngeal carcinoma (NPC), iTRAQ-tagging combined with 2D LC-MS/MS analysis was performed to identify the differentially expressed proteins (DEPs) in high metastatic NPC 5-8F cells and non-metastatic NPC 6-10B cells, and qRT-PCR and Western blotting were used to confirm DEPs. As a result, 101 DEPs were identified by proteomics, and 12 DEPs were selectively validated. We further detected expression of three DEPs (RAN, SQSTM1 and TRIM29) in a cohort of NPC tissue specimens to assess their value as NPC metastatic biomarkers, and found that combination of RAN, SQSTM1 and TRIM29 could discriminate metastatic NPC from non-metastatic NPC with a sensitivity of 88% and a specificity of 91%. TRIM29 and RAN expression level were closely correlated with lymph node and distant metastasis and clinical stage (P <0.05) in NPC patients. Finally, a combination of loss-of-function and gain-of-function approaches was performed to determine the effects of TRIM29 on NPC cell proliferation, migration, invasion and metastasis. The results showed that TRIM29 knockdown significantly attenuated while TRIM29 overexpression promoted NPC cell in vitro proliferation, migration and invasion and in vivo metastasis. The present data first time show that SQSTM1, RAN and TRIM29 are novel potential biomarkers for predicting NPC metastasis, demonstrate that TRIM29 is a metastasis-promoted protein of NPC.

TRIM29 promotes DNA virus infections by inhibiting innate immune response

Many double-stranded DNA viruses, such as Epstein-Barr virus, can establish persistent infection, but the underlying virus-host interactions remain poorly understood. Here we report that in human airway epithelial cells Epstein-Barr virus induces TRIM29, a member of the TRIM family of proteins, to inhibit innate immune activation. Knockdown of TRIM29 in airway epithelial cells enhances type I interferon production, and in human nasopharyngeal carcinoma cells results in almost complete Epstein-Barr virus clearance. TRIM29 is also highly induced by cytosolic double-stranded DNA in myeloid dendritic cells. TRIM29 ^-/- mice have lower adenovirus titers in the lung, and are resistant to lethal herpes simplex virus-1 infection due to enhanced production of type I interferon. Mechanistically, TRIM29 induces K48-linked ubiquitination of Stimulator of interferon genes, a key adaptor in double-stranded DNA-sensing pathway, followed by its rapid degradation. These data demonstrate that Epstein-Barr virus and possible other double-stranded DNA viruses use TRIM29 to suppress local innate immunity, leading to the persistence of DNA virus infections.Proteins of the TRIM family have regulatory functions in immune signaling, often via ubiquitination of target proteins. Here, the authors show that TRIM29 is induced upon infection with DNA viruses, resulting in degradation of STING, decreased interferon signaling and increased pathogenicity in mice.

Meta-analysis of gene expression studies in endometrial cancer identifies gene expression profiles associated with aggressive disease and patient outcome

Although endometrioid endometrial cancer (EEC; comprising ~80% of all endometrial cancers diagnosed) is typically associated with favourable patient outcome, a significant portion (~20%) of women with this subtype will relapse. We hypothesised that gene expression predictors of the more aggressive non-endometrioid endometrial cancers (NEEC) could be used to predict EEC patients with poor prognosis. To explore this hypothesis, we performed meta-analysis of 12 gene expression microarray studies followed by validation using RNA-Seq data from The Cancer Genome Atlas (TCGA) and identified 1,253 genes differentially expressed between EEC and NEEC. Analysis found 121 genes were associated with poor outcome among EEC patients. Forward selection likelihood-based modelling identified a 9-gene signature associated with EEC outcome in our discovery RNA-Seq dataset which remained significant after adjustment for clinical covariates, but was not significant in a smaller RNA-Seq dataset. Our study demonstrates the value of employing meta-analysis to improve the power of gene expression microarray data, and highlight genes and molecular pathways of importance for endometrial cancer therapy.

Immunomodulatory and Transcriptional Effects of Progesterone Through Progesterone A and B Receptors in Hec50co Poorly Differentiated Endometrial Cancer Cells

OBJECTIVE

Derivatives of progesterone, progestins, are used to treat endometrial cancer; however, the pathways activated by the hormone have not been fully investigated. Progesterone acts through two receptor isoforms, progesterone receptors A and B (PRA and PRB), transcription factors that control the expression of downstream genes leading to endometrial differentiation. The purpose of this study was to perform an expression analysis to identify the mechanisms underlying progesterone's growth suppressive and immunomodulatory effects in endometrial cancer.

METHODS

To study the molecular effects of progesterone, PRs were introduced into Hec50co cells. Expression array analyses followed by confirmatory semiquantitive reverse-transcriptase polymerase chain reaction (RT-PCR) experiments were performed.

RESULTS

Expression analysis demonstrated a significant effect of progesterone after 12 hours of treatment on a number of genes, including cell signaling, DNA remodeling, apoptotic, tumor-suppressor, and transcription factors. Of particular interest was the consistent modulation of cytokines, which generally predicted for a powerful anti-inflammatory effect of progesterone through PR. Specifically, pro-inflammatory genes such as TNFalpha, IL-1beta, and MCP-1/MCAF-1 were down-regulated and anti-inflammatory genes such as TRAP1 and SMAD4 were induced.

CONCLUSION

We have discovered that progesterone has a modulatory effect on inflammation and many other important cellular functions. These effects likely underlie the inhibitory effects of progesterone on tumor growth and invasion.

Five endometrial cancer risk loci identified through genome-wide association analysis

We conducted a meta-analysis of three endometrial cancer genome-wide association studies (GWAS) and two follow-up phases totaling 7,737 endometrial cancer cases and 37,144 controls of European ancestry. Genome-wide imputation and meta-analysis identified five new risk loci of genome-wide significance at likely regulatory regions on chromosomes 13q22.1 (rs11841589, near KLF5), 6q22.31 (rs13328298, in LOC643623 and near HEY2 and NCOA7), 8q24.21 (rs4733613, telomeric to MYC), 15q15.1 (rs937213, in EIF2AK4, near BMF) and 14q32.33 (rs2498796, in AKT1, near SIVA1). We also found a second independent 8q24.21 signal (rs17232730). Functional studies of the 13q22.1 locus showed that rs9600103 (pairwise r(2) = 0.98 with rs11841589) is located in a region of active chromatin that interacts with the KLF5 promoter region. The rs9600103[T] allele that is protective in endometrial cancer suppressed gene expression in vitro, suggesting that regulation of the expression of KLF5, a gene linked to uterine development, is implicated in tumorigenesis. These findings provide enhanced insight into the genetic and biological basis of endometrial cancer.

Upregulated TRIM29 promotes proliferation and metastasis of nasopharyngeal carcinoma via PTEN/AKT/mTOR signal pathway

Tripartite motif-containing 29 (TRIM29) has been reported to be dysregulated in human cancers. Up-regulation of TRIM29 was first observed in NPC cell lines by a genome-wide transcriptome analysis in our previous study. However, its expression biological function and clinical significance in nasopharyngeal carcinoma (NPC) remain unclear. In this study, TRIM29 expression was validated by qRT-PCR and immunohistochemistry in 69 NPC samples. Notably, TRIM29 protein expression was significantly and positively correlated with the tumor size, clinical stage and metastasis. TRIM29 was identified as the direct target of miR-335-5p and miR-15b-5p, both of which were down-regulated and negatively associated with TRIM29 expression in NPC cell lines and clinical samples. Ectopic TRIM29 expression promoted proliferation, epithelial-mesenchymal transition (EMT), migration and invasion in NPC cells, while its depletion inhibited cell invasion and EMT phenotype. Mechanistically, TRIM29 overexpression reduced PTEN expression and increase phosphorylated protein level of AKT, p70S6K and 4E-BP1. Correspondingly, AKT inhibitor and Rapamycin blocked the effect of TRIM29 on cell invasion. In conclusion, our results suggest that miR-335-5p and miR-15b-5p down-regulation results in TRIM29 over-expression, which induces proliferation, EMT and metastasis of NPC through the PTEN/AKT/mTOR signaling pathway.

Statistical Issues in the Design and Analysis of nCounter Projects

Numerous statistical methods have been published for designing and analyzing microarray projects. Traditional genome-wide microarray platforms (such as Affymetrix, Illumina, and DASL) measure the expression level of tens of thousands genes. Since the sets of genes included in these array chips are selected by the manufacturers, the number of genes associated with a specific disease outcome is limited and a large portion of the genes are not associated. nCounter is a new technology by NanoString to measure the expression of a selected number (up to 800) of genes. The list of genes for nCounter chips can be selected by customers. Due to the limited number of genes and the price increase in the number of selected genes, the genes for nCounter chips are carefully selected among those discovered from previous studies, usually using traditional high-throughput platforms, and only a small number of definitely unassociated genes, called control genes, are included to standardize the overall expression level across different chips. Furthermore, nCounter chips measure the expression level of each gene using a counting observation while the traditional high-throughput platforms produce continuous observations. Due to these differences, some statistical methods developed for the design and analysis of high-throughput projects may need modification or may be inappropriate for nCounter projects. In this paper, we discuss statistical methods that can be used for designing and analyzing nCounter projects.

Nationwide high prevalence of CTX-M and an increase of CTX-M-55 in Escherichia coli isolated from patients with community-onset infections in Chinese county hospitals

BACKGROUND

In order to investigate the epidemiology, molecular characteristics, and distribution of extended-spectrum β-lactamase (ESBL)- and AmpC-producing Escherichia coli from community-onset infections in Chinese county hospitals.

METHODS

E. coli isolates were collected from patients with community-onset infections in 30 county hospitals. ESBL activity was confirmed by double-disc diffusion. Genetic confirmation and molecular typing of ESBL- and AmpC-producing isolates was determined by PCR and DNA sequencing. ESBL-positive isolates were further characterised by multi-locus sequence typing.

RESULTS

Of 550 E. coli isolates, 256 (46.5%) carried ESBL genes and all were of the CTX-M type. The prevalence of ESBL-producing strains varied from 30.2% to 57.0% across different regions of China. Overall, 12 bla CTX-M subtypes were detected; the most abundant were bla CTX-M-14 (163/256 isolates, 64.5%), bla CTX-M-55 (47/256, 18.4%), and bla CTX-M-15 (31/256, 12.1%). CMY-2-like AmpC β-lactamases were detected in 11 strains, three of which co-existed with bla CTX-M. A total of 64 sequence types (STs) were detected in 256 ESBL-producing strains, including nine that were new. ST131 was the most abundant type (27 isolates, 12.7%), followed by ST69 (14 isolates, 6.6%), ST405 (14 isolates, 6.6%), and ST38 (12 isolates, 5.6%).

CONCLUSIONS

This study revealed that the widespread prevalence of ESBLs among outpatient infections has reached a high level in county hospitals. The CTX-M genotype was most dominant, comprising a variety of subtypes. This is the first time the incidence of CTX-M-55 has exceeded that of CTX-M-15 in China. No predominant ST was detected, suggesting that ESBL-producing E. coli strains originate in different clones.

L-Carnitine: a new insight into the pathogenesis of endometrial cancer

OBJECTIVES

The present study aims to specify the role of L-carnitine in the pathogenesis of endometrial cancer by comparing the serum total L-carnitine levels of endometrial cancer patients with those of healthy women.

METHODS

Serum total L-carnitine concentrations were measured in patients with endometrioid-type endometrial cancer (n = 20) and healthy controls (n = 20) who were matched with respect to age and body mass index (BMI).

RESULTS

Stage I endometrial cancer was diagnosed in 12 women (60.0%) whereas three women (15.0%) had stage II disease, three women (15.0%) had stage III disease and two women (10.0%) had stage IV disease. The healthy controls and endometrial cancer patients were statistically similar in aspect of age, gravidity, parity, BMI, waist-to-thigh ratio, waist-to-hip ratio, menopause, complete blood count parameters, and serum biochemistry. Serum total L-carnitine levels of women with endometrial cancer were significantly lower than those of healthy women (respectively, 5,519.4 ± 2,712.5 vs 7,940.8 ± 3,566.6 ng/dl, p = 0.021). Moreover, serum total L-carnitine levels decreased significantly and progressively with advancing stage (stage I vs II vs III vs IV; 6,294.0 ± 2,885.1 vs 5,800.0 ± 441.2 vs 4,016.0 ± 2,833.3 vs 2,560.0 ± 67.9 ng/dl; p = 0.021).

CONCLUSIONS

This is the first study to hypothesize that L-carnitine deficiency participates in the pathogenesis of endometrial cancer by means of a mechanism which is unrelated with obesity and increased amount of fat in human body.

Clinical significance of CTNNB1 mutation and Wnt pathway activation in endometrioid endometrial carcinoma

BACKGROUND

Endometrioid endometrial carcinoma (EEC) is the most common form of endometrial carcinoma. The heterogeneous clinical course of EEC is an obstacle to individualized patient care.

METHODS

We performed an integrated analysis on the multiple-dimensional data types including whole-exome and RNA sequencing, RPPA profiling, and clinical data from 271 EEC cases in The Cancer Genome Atlas (TCGA) to identify molecular fingerprints that may account for this clinical heterogeneity. Significance analysis of microarray was used to identify marker genes of each subtype that were subject to pathway analysis. Association of molecular subtypes with clinical features and mutation data was analyzed with the Mann Whitney, Chi-square, Fisher's exact, and Kruskal-Wallis tests. Survival analysis was evaluated with log-rank test. All statistical tests were two-sided.

RESULTS

Four transcriptome subtypes with distinct clinicopathologic characteristics and mutation spectra were identified from the TCGA dataset and validated in an independent sample cohort of 184 EEC cases. Cluster II consisted of younger, obese patients with low-grade EEC but diminished survival. CTNNB1 exon 3 mutations were present in 87.0% (47/54) of Cluster II (P < .001) that exhibited a low overall mutation rate; this was statistically significantly associated with Wnt/β-catenin signaling activation (P < .001). High expression levels of CTNNB1 (P = .001), MYC (P = .01), and CCND1 (P = .01) were associated with poorer overall survival in low-grade EEC tumors.

CONCLUSIONS

CTNNB1 exon 3 mutations are likely a driver that characterize an aggressive subset of low-grade and low-stage EEC occurring in younger women.

KLF9, a transcription factor induced in flutamide-caused cell apoptosis, inhibits AKT activation and suppresses tumor growth of prostate cancer cells

BACKGROUND

Kruppel-like factors (KLFs) are involved in various biological processes; emerging studies have indicated that KLF9 plays a critical role in regulating tumorigenesis. The role of KLF9 in prostate cancer (PCa), however, has not yet been investigated.

METHODS

The expression of KLF members, AKT- and apoptosis-related proteins were analyzed by Western blot or qRT-PCR. Tet-On inducible KLF9 expression was established for the evaluation of the effects of KLF9 on cell proliferation, apoptosis, and xenograft tumor growth in nude mice. Cell cycle and apoptosis were determined by flow cytometry.

RESULTS

KLF9 was induced in a time-dependent manner in flutamide-caused apoptosis, and knockdown of KLF9 significantly decreased flutamide-induced growth inhibition and apoptosis in LNCaP cells. The levels of KLF9 were relatively lower in PCa cell lines, particularly in androgen-independent cell lines compared with those in nontumorous prostate epithelial cell lines. Overexpression of KLF9 dramatically suppressed cell proliferation and caused cell cycle arrest in the G2/M phase and cell apoptosis in the androgen-independent cell lines, PC3 and DU145. Intriguingly, KLF9 expression severely suppressed the activation of AKT and its downstream targets. AKT reactivation partially rescued the KLF9-mediated inhibitory effects on the proliferation of PCa cells. More importantly, we found that KLF9 overexpression efficiently inhibited the xenograft tumor growth of PCa cells.

CONCLUSIONS

These data collectively showing that KLF9 substantially inhibits AKT activation and abrogates tumor growth of PCa cells, suggest the potential of either genetic or pharmacological activation of KLF9 in the therapeutic treatment of castration-resistant PCa.

TRIM29 as a novel prostate basal cell marker for diagnosis of prostate cancer

Tripartite motif protein 29 (TRIM29) is one of the TRIM family proteins, some of which function as E3 ubiquitin ligases. In this study, we investigated the usefulness of TRIM29 for diagnosis of prostate cancer. Prostate tissues including carcinoma and non-carcinoma tissues obtained by needle biopsy and radical prostatectomy were used. Immunohistochemistry was performed according to standard procedures using an antibody against TRIM29. Immunohistochemical staining with an antibody against 34βE12, which recognizes cytokeratins 1, 5, 10 and 14, was performed as a control. Basal cells of normal prostatic glands were stained with anti-TRIM29 antibody in all cases, whereas prostate cancer tissues had no or little staining with anti-TRIM29 antibody. TRIM29 is selectively expressed in basal cells of the normal prostate gland, and immunohistochemical staining with anti-TRIM29 antibody showed the same expression pattern as that with 34βE12 in prostate cancer and its benign mimics. Our data indicate that TRIM29 may be useful for distinguishing prostate cancers from benign tissues.

TRIM29 as a novel biomarker in pancreatic adenocarcinoma

Background and Aim. Tripartite motif-containing 29 (TRIM29) is structurally a member of the tripartite motif family of proteins and is involved in diverse human cancers. However, its role in pancreatic cancer remains unclear. Methods. The expression pattern of TRIM29 in pancreatic ductal adenocarcinoma was assessed by immunocytochemistry. Multivariate logistic regression analysis was used to investigate the association between TRIM29 and clinical characteristics. In vitro analyses by scratch wound healing assay and invasion assays were performed using the pancreatic cancer cell lines. Results. Immunohistochemical analysis showed TRIM29 expression in pancreatic cancer tissues was significantly higher  (n = 186) than that in matched adjacent nontumor tissues. TRIM29 protein expression was significantly correlated with lymph node metastasis (P = 0.019). Patients with positive TRIM29 expression showed both shorter overall survival and shorter recurrence-free survival than those with negative TRIM29 expression. Multivariate analysis revealed that TRIM29 was an independent factor for pancreatic cancer over survival (HR = 2.180, 95% CI: 1.324–4.198, P = 0.011). In vitro, TRIM29 knockdown resulted in inhibition of pancreatic cancer cell proliferation, migration, and invasion. Conclusions. Our results indicate that TRIM29 promotes tumor progression and may be a novel prognostic marker for pancreatic ductal adenocarcinoma.

RASSF10 is an epigenetically silenced tumor suppressor in gastric cancer

To better understand the role of the N-Terminal Ras association domain family (RASSF) genes in the development of gastric cancer, we examined the expression of RASSF7 and RASSF10 and RASSF10 methylation in gastric cancer. We found that RASSF10 expression was lost in six gastric cancer cell lines, and was rescued by a DNA demethylating agent and a histone deacetylase inhibitor. However, RASSF7 expression was strong in four cancer cell lines as well as in 87% of primary gastric cancer tissues. In contrast, RASSF7 expression was moderate in the GES-1 cell line and negative in 33.3% of the corresponding non-cancerous tissues. Analysis of RASSF10 methylation by methylation-specific PCR (MSP) and sequencing revealed that the methylation frequency in primary gastric carcinoma tissues was significantly higher compared to that in adjacent non-carcinoma tissues (61.6 vs. 38.4%; p<0.01). The methylation frequency in the tumor with invasion depth at T3 and T4 was significantly higher compared to that with invasion depth at T1 and T2 (67.1 vs. 37.5%; p<0.05). Hypermethylation of RASSF10 was found in the patients with lymph node metastasis, compared to those with unaffected lymph nodes (68.8 vs. 40.9%; p<0.05). Among the 4 gross types of the Borrmann classification, i.e. EGC, Borrmann Ⅰ, Borrmann Ⅱ, Borrmann Ⅲ and Borrmann Ⅳ, the last one was more frequently methylated (85.7 vs. 56.9%; p<0.05). The present study revealed that RASSF10 is an epigenetically silenced gene involved in tumor invasion and metastasis in gastric cancer, suggesting that the methylation status of RASSF10 may be a useful indicator to predict the malignant degree of gastric cancer.

Patterns of TPD52 overexpression in multiple human solid tumor types analyzed by quantitative PCR

Tumor protein D52 (TPD52) is located at chromosome 8q21, a region that is frequently gained or amplified in multiple human cancer types. TPD52 has been suggested as a potential target for new anticancer therapies. In order to analyze TPD52 expression in the most prevalent human cancer types, we employed quantitative PCR to measure TPD52 mRNA levels in formalin-fixed tissue samples from more than 900 cancer tissues obtained from 29 different human cancer types. TPD52 was expressed at varying levels in all tested normal tissues, including skin, lymph node, lung, oral mucosa, breast, endometrium, ovary, vulva, myometrium, liver, pancreas, stomach, kidney, prostate, testis, urinary bladder, thyroid gland, brain, muscle and fat tissue. TPD52 was upregulated in 18/29 (62%) tested cancer types. Strongest expression was found in non-seminoma (56-fold overexpression compared to corresponding normal tissue), seminoma (42-fold), ductal (28-fold) and lobular breast cancer (14-fold). In these tumor types, TPD52 upregulation was found in the vast majority (>80%) of tested samples. Downregulation was found in 11 (38%) tumor types, most strongly in papillary renal cell cancer (-8-fold), leiomyosarcoma (-6-fold), clear cell renal cell cancer (-5-fold), liposarcoma (-5-fold) and lung cancer (-4-fold). These results demonstrate that TPD52 is frequently and strongly upregulated in many human cancer types, which may represent candidate tumor types for potential anti-TPD52 therapies.

Up-regulation of tripartite motif-containing 29 promotes cancer cell proliferation and predicts poor survival in colorectal cancer

Tripartite motif-containing 29 (TRIM29), also known as ataxia-telangiectasia group D, is structurally a member of the tripartite motif family of proteins, which characterized by the conserved RING finger, B-box, and coiled-coil domains. TRIM29 functions as an oncogene or a tumor suppressor depending on the tumor types. In this study, we aim to evaluate whether TRIM29 affects the tumorigenesis and progression of colorectal cancer. The expression of TRIM29 was investigated using real-time PCR in 40 pairs of colorectal cancer tissues and immunohistochemistry on a tissue microarray containing 203 cases of primary colorectal cancer paired with non-cancerous tissues. Down-regulation of TRIM29 was achieved by transient transfection in RKO cell lines, and the effects of TRIM29 on tumor proliferation were evaluated by MTT and plate colony formation assays. Results indicated that TRIM29 expression was much higher in colorectal cancer tissues and significantly associated with the depth of tumor invasion, lymph node metastasis, distant metastasis, histological differentiation, vascular invasion, ki-67 index, and advanced tumor stage. Patients with TRIM29-positive tumors had a higher recurrence rate and poorer survival than patients with TRIM29-negative tumors. In multivariate analyses, the TRIM29 expression was an independent factor for determining colorectal cancer prognosis after surgery. Moreover, down-regulation of TRIM29 inhibited tumor cell proliferation in vitro. In conclusion, TRIM29 plays an important role in promoting colorectal cancer progression. Our findings suggest that TRIM29 may serve as a novel biomarker for tumor recurrence and survival for colorectal cancer patients.

Gene expression analysis of early stage endometrial cancers reveals unique transcripts associated with grade and histology but not depth of invasion

Endometrial cancer is the most common gynecologic malignancy in the United States but it remains poorly understood at the molecular level. This investigation was conducted to specifically assess whether gene expression changes underlie the clinical and pathologic factors traditionally used for determining treatment regimens in women with stage I endometrial cancer. These include the effect of tumor grade, depth of myometrial invasion and histotype. We utilized oligonucleotide microarrays to assess the transcript expression profile in epithelial glandular cells laser microdissected from 79 endometrioid and 12 serous stage I endometrial cancers with a heterogeneous distribution of grade and depth of myometrial invasion, along with 12 normal post-menopausal endometrial samples. Unsupervised multidimensional scaling analyses revealed that serous and endometrioid stage I cancers have similar transcript expression patterns when compared to normal controls where 900 transcripts were identified to be differentially expressed by at least fourfold (univariate t-test, p < 0.001) between the cancers and normal endometrium. This analysis also identified transcript expression differences between serous and endometrioid cancers and tumor grade, but no apparent differences were identified as a function of depth of myometrial invasion. Four genes were validated by quantitative PCR on an independent set of cancer and normal endometrium samples. These findings indicate that unique gene expression profiles are associated with histologic type and grade, but not myometrial invasion among early stage endometrial cancers. These data provide a comprehensive perspective on the molecular alterations associated with stage I endometrial cancer, particularly those subtypes that have the worst prognosis.

Ataxia-telangiectasia group D complementing gene (ATDC) promotes lung cancer cell proliferation by activating NF-κB pathway

Previous studies suggested Ataxia-telangiectasia group D complementing gene (ATDC) as an oncogene in many types of cancer. However, its expression and biological functions in non-small cell lung cancer (NSCLC) remain unclear. Herein, we investigated its expression pattern in 109 cases of human NSCLC samples by immunohistochemistry and found that ATDC was overexpressed in 62 of 109 NSCLC samples (56.88%). ATDC overexpression correlated with histological type (p<0.0001), tumor status (p = 0.0227) and histological differentiation (p = 0.0002). Next, we overexpressed ATDC in normal human bronchial epithelial cell line HBE and depleted its expression in NSCLC cell lines A549 and H1299. MTT and colony formation assay showed that ATDC overexpression promoted cell proliferation while its depletion inhibited cell growth. Furthermore, cell cycle analysis showed that ATDC overexpression decreased the percentage of cells in G1 phase and increased the percentage of cells in S phase, while ATDC siRNA treatment increased the G1 phase percentage and decreased the S phase percentage. Further study revealed that ATDC overexpression could up-regulate cyclin D1 and c-Myc expression in HBE cells while its depletion down-regulated cyclin D1 and c-Myc expression in A549 and H1299 cells. In addition, ATDC overexpression was also associated with an increased proliferation index, cyclin D1 and c-Myc expression in human NSCLC samples. Further experiments demonstrated that ATDC up-regulated cyclin D1 and c-Myc expression independent of wnt/β-catenin or p53 signaling pathway. Interestingly, ATDC overexpression increased NF-κB reporter luciferase activity and p-IκB protein level. Correspondingly, NF-κB inhibitor blocked the effect of ATDC on up-regulation of cyclin D1 and c-Myc. In conclusion, we demonstrated that ATDC could promote lung cancer proliferation through NF-κB induced up-regulation of cyclin D1 and c-Myc.

Expression and roles of steroidogenic acute regulatory (StAR) protein in 'non-classical', extra-adrenal and extra-gonadal cells and tissues

The activity of the steroidogenic acute regulatory (StAR) protein is indispensable and rate limiting for high output synthesis of steroid hormones in the adrenal cortex and the gonads, known as the 'classical' steroidogenic organs (StAR is not expressed in the human placenta). In addition, studies of recent years have shown that StAR is also expressed in many tissues that produce steroid hormones for local use, potentially conferring some functional advantage by acting via intracrine, autocrine or paracrine fashion. Others hypothesized that StAR might also function in non-steroidogenic roles in specific tissues. This review highlights the evidence for the presence of StAR in 17 extra-adrenal and extra-gonadal organs, cell types and malignancies. Provided is the physiological context and the rationale for searching for the presence of StAR in such cells. Since in many of the tissues the overall level of StAR is relatively low, we also reviewed the methods used for StAR detection. The gathered information suggests that a comprehensive understanding of StAR activity in 'non-classical' tissues will require the use of experimental approaches that are able to analyze StAR presence at single-cell resolution.

Upregulated ataxia-telangiectasia group D complementing gene correlates with poor prognosis in patients with esophageal squamous cell carcinoma

The ataxia-telangiectasia group D complementing gene (ATDC) plays significant roles in various human cancers. However, the clinical significance of ATDC in esophageal squamous cell carcinoma (ESCC) has not been investigated. The ATDC messenger RNA level of 40 paired ESCC and nonneoplastic tissues were evaluated using quantitative real-time polymerase chain reaction, 10 pairs of which were also used for Western blot analysis. In addition, immunohistochemical staining was performed to detect the ATDC expression in 118 paraffin-embedded cancerous and matched nonneoplastic tissues, and the correlation of ATDC expression with the clinicopathological parameters and prognosis of the ESCC patients was analyzed. The quantitative real-time polymerase chain reaction, immunohistochemical staining, and Western blot results demonstrated that the expression level of ATDC was significantly higher in ESCC tissue than in matched noncancerous tissues. Both ATDC messenger RNA and protein expression in the ESCC tissue were significantly correlated with tumor differentiation, stage, and lymph node metastasis. However, there was no significant difference in ATDC expression based on patient age or gender. Moreover, the results of both univariate and multivariate analyses showed that increased ATDC expression was correlated with a shorter 5-year survival time for ESCC patients after surgery. We concluded that increased ATDC expression is associated with poor clinical outcomes and that this marker might be a useful indicator for prognosis and a promising target for therapy in ESCC patients.

Plasma membrane proteomics identifies bone marrow stromal antigen 2 as a potential therapeutic target in endometrial cancer

This report utilizes a novel proteomic method for discovering potential therapeutic targets in endometrial cancer. We used a biotinylation-based approach for cell-surface protein enrichment combined with isobaric tags for relative and absolute quantitation (iTRAQ) technology using nano liquid chromatography-tandem mass spectrometry analysis to identify specifically overexpressed proteins in endometrial cancer cells compared with normal endometrial cells. We identified a total of 272 proteins, including 11 plasma membrane proteins, whose expression increased more than twofold in at least four of seven endometrial cancer cell lines compared with a normal endometrial cell line. Overexpression of bone marrow stromal antigen 2 (BST2) was detected and the observation was supported by immunohistochemical analysis using clinical samples. The expression of BST2 was more characteristic of 118 endometrial cancer tissues compared with 59 normal endometrial tissues (p < 0.0001). The therapeutic effect of an anti-BST2 antibody was studied both in vitro and in vivo. An anti-BST2 monoclonal antibody showed in vitro cytotoxicity in BST2-positive endometrial cancer cells via antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity. In an in vivo xenograft model, anti-BST2 antibody treatment significantly inhibited tumor growth of BST2-positive endometrial cancer cells in an NK cell-dependent manner. The anti-BST2 antibody had a potent antitumor effect against endometrial cancer both in vitro and in vivo, indicating a strong potential for clinical use of anti-BST2 antibody for endometrial cancer treatment. The combination of biotinylation-based enrichment of cell-surface proteins and iTRAQ analysis should be a useful screening method for future discovery of potential therapeutic targets.

RASSF Signalling and DNA Damage: Monitoring the Integrity of the Genome?

The RASSF family of proteins has been extensively studied in terms of their genetics, structure and function. One of the functions that has been increasingly studied is the role of the RASSF proteins in the DNA damage response. Surprisingly, this research, which encompasses both the classical and N-terminal RASSF proteins, has revealed an involvement of the RASSFs in oncogenic pathways as well as the more familiar tumour suppressor pathways usually associated with the RASSF family members. The most studied protein with respect to DNA damage is RASSF1A, which has been shown, not only to be activated by ATM, a major regulator of the DNA damage response, but also to bind to and activate a number of different pathways which all lead to and feedback from the guardian of the genome, p53. In this review we discuss the latest research linking the RASSF proteins to DNA damage signalling and maintenance of genomic integrity and look at how this knowledge is being utilised in the clinic to enhance the effectiveness of traditional cancer therapies such as radiotherapy.

TRIM proteins and cancer

Emerging clinical evidence shows that the deregulation of ubiquitin-mediated degradation of oncogene products or tumour suppressors is likely to be involved in the aetiology of carcinomas and leukaemias. Recent studies have indicated that some members of the tripartite motif (TRIM) proteins (one of the subfamilies of the RING type E3 ubiquitin ligases) function as important regulators for carcinogenesis. This Review focuses on TRIM proteins that are involved in tumour development and progression.

β-catenin as a potential key target for tumor suppression

β-catenin is a multifunctional protein identified to be pivotal in embryonic patterning, organogenesis and adult homeostasis. It plays a critical structural role in mediating cadherin junctions and is also an essential transcriptional co-activator in the canonical Wnt pathway. Evidence has been documented that both the canonical Wnt pathway and cadherin junctions are deregulated or impaired in a plethora of human malignancies. In the light of this, there has been a recent surge in elucidating the mechanisms underlying the etiology of cancer development from the perspective of β-catenin. Here, we focus on the emerging roles of β-catenin in the process of tumorigenesis by discussing novel functions of old players and new proteins, mechanisms identified to mediate or interact with β-catenin and the most recently unraveled clinical implications of β-catenin regulatory pathways toward tumor suppression.

Krüppel-like factor 9 loss-of-expression in human endometrial carcinoma links altered expression of growth-regulatory genes with aberrant proliferative response to estrogen

Endometrial cancer is the most commonly diagnosed female genital tract malignancy. Krüppel-like factor 9 (KLF9), a member of the evolutionarily conserved Sp family of transcription factors, is expressed in uterine stroma and glandular epithelium, where it affects cellular proliferation, differentiation, and apoptosis. Deregulated expression of a number of Sp proteins has been associated with multiple types of human tumors, but a role for KLF9 in endometrial cancer development and/or progression is unknown. Here, we evaluated KLF9 expression in endometrial tumors and adjacent uninvolved endometrium of women with endometrial carcinoma. KLF9 mRNA and protein levels were lower in endometrial tumors coincident with decreased expression of family member KLF4 and growth-regulators FBJ murine osteosarcoma viral oncogene homolog (FOS) and myelocytomatosis viral oncogene homolog (MYC) and with increased expression of telomerase reverse transcriptase (TERT) and the chromatin-modifying enzymes DNA methyltransferase 1 (DNMT1) and histone deacetylase 3 (HDAC3). Expression of estrogen receptor alpha (ESR1) and the tumor-suppressor phosphatase and tensin homolog deleted in chromosome 10 (PTEN) did not differ between tumor and normal tissue. The functional relevance of attenuated KLF9 expression in endometrial carcinogenesis was further evaluated in the human endometrial carcinoma cell line Ishikawa by siRNA targeting. KLF9 depletion resulted in loss of normal cellular response to the proliferative effects of estrogen concomitant with reductions in KLF4 and MYC and with enhancement of TERT and ESR1 gene expression. Silencing of KLF4 did not mimic the effects of silencing KLF9 in Ishikawa cells. We suggest that KLF9 loss-of-expression accompanying endometrial carcinogenesis may predispose endometrial epithelial cells to mechanisms of escape from estrogen-mediated growth regulation, leading to progression of established neoplasms.

TRIM29 negatively regulates p53 via inhibition of Tip60

Ataxia-telangiectasia (AT) is an autosomal recessive genetic disease characterized by immunological deficiencies, neurological degeneration, developmental abnormalities and an increased risk of cancer. Ataxia-telangiectasia group D (ATDC) was initially described as a gene related to AT. Ataxia-telangiectasia group D, also known as TRIM29, is structurally a member of the tripartite motif (TRIM) family of proteins, some of which have been reported to be highly expressed in some human carcinomas, but the involvement of TRIM29 in carcinogenesis has not been fully elucidated. In this study, we found by using yeast two-hybrid screening that TRIM29 binds to Tip60, which has been reported as a cellular acetyltransferase protein. Overexpression of TRIM29 promoted degradation and changed localization of Tip60 and reduced acetylation of p53 at lysine 120 by Tip60, resulting in enhancement of cell growth and transforming activity. In addition, we found that TRIM29 suppresses apoptosis induced by UV irradiation in HCT116 cell lines. These findings suggest that TRIM29 functions as an oncogene that promotes tumor growth.

Proteomic analysis of stage I endometrial cancer tissue: identification of proteins associated with oxidative processes and inflammation

OBJECTIVE

The present study aimed to identify differentially expressed proteins employing a high resolution mass spectrometry (MS)-based proteomic analysis of endometrial cancer cells harvested using laser microdissection.

METHODS

A differential MS-based proteomic analysis was conducted from discrete epithelial cell populations gathered by laser microdissection from 91 pathologically reviewed stage I endometrial cancer tissue samples (79 endometrioid and 12 serous) and 10 samples of normal endometrium from postmenopausal women. Hierarchical cluster analysis of protein abundance levels derived from a spectral count analysis revealed a number of proteins whose expression levels were common as well as unique to both histologic types. An independent set of endometrial cancer specimens from 394 patients were used to externally validate the differential expression of select proteins.

RESULTS

209 differentially expressed proteins were identified in a comparison of stage I endometrial cancers and normal post-menopausal endometrium controls (Q<0.005). A number of differentially abundant proteins in stage I endometrial cancer were identified and independently validated by western blot and tissue microarray analyses. Multiple proteins identified with elevated abundance in stage I endometrial cancer are functionally associated with inflammation (annexins) and oxidative processes (peroxiredoxins). PRDX1 and ANXA2 were both confirmed as being overexpressed in stage I cancer compared to normal endometrium by independent TMA (Q=0.008 and Q=0.00002 respectively).

CONCLUSIONS

These data provide the basis for further investigation of previously unrecognized novel pathways involved in early stage endometrial carcinogenesis and provide possible targets for prevention strategies that are inclusive of both endometrioid and serous histologic subtypes.

Progesterone: the ultimate endometrial tumor suppressor

The uterine endometrium is exquisitely sensitive to steroid hormones that act through well-described nuclear receptors. Estrogen drives epithelial proliferation, and progesterone inhibits growth and causes cell differentiation. The importance of progesterone as a key inhibitor of carcinogenesis is reflected by the observation that women who ovulate and produce progesterone almost never get endometrial cancer. In this review we describe seminal research findings that define progesterone as the major endometrial tumor suppressor. We discuss the genes and diverse signaling pathways that are controlled by progesterone through progesterone receptors (PRs) and also the multiple factors that regulate progesterone/PR activity. By defining these progesterone-regulated factors and pathways we identify the principal therapeutic opportunities to control the growth of endometrial cancer.

N-terminal RASSF family: RASSF7-RASSF10

Epigenetic inactivation of tumor suppressor genes is a hallmark of cancer development. RASSF1A (Ras Association Domain Family 1 isoform A) tumor suppressor gene is one of the most frequently epigenetically inactivated genes in a wide range of adult and children's cancers and could be a useful molecular marker for cancer diagnosis and prognosis. RASSF1A has been shown to play a role in several biological pathways, including cell cycle control, apoptosis and microtubule dynamics. RASSF2, RASSF4, RASSF5 and RASSF6 are also epigenetically inactivated in cancer but have not been analysed in as wide a range of malignancies as RASSF1A. Recently four new members of the RASSF family were identified these are termed N-Terminal RASSF genes (RASSF7-RASSF10). Molecular and biological analysis of these newer members has just begun. This review highlights what we currently know in respects to structural, functional and molecular properties of the N-Terminal RASSFs.

CDC23 regulates cancer cell phenotype and is overexpressed in papillary thyroid cancer

Cancer gender disparities have been observed for a variety of human malignancies. Thyroid cancer is one such example where there is a dramatic difference in the incidence, aggressiveness, and death rate by gender. The molecular basis for gender disparity is poorly understood. To address this, we performed genome-wide gene expression profiling in matched papillary thyroid cancer (PTC) samples and identified nine candidate genes differentially expressed by gender. One of these genes was CDC23 that was upregulated in PTC in men compared with women. Because the function and expression of CDC23 is unknown in eukaryotic cells, we further characterized the expression of CDC23 in normal, hyperplastic, and PTC tissue samples. We found CDC23 was overexpressed in PTC and absent in normal and hyperplastic thyroid tissue. In thyroid cancer cells, functional knockdown of CDC23 resulted in an increase in the number of cells in both the S and G(2)M phases of the cell cycle, and an inhibition of cellular proliferation, tumor spheroid formation, and anchorage-independent growth. Cellular arrest in both S and G(2)M phases was associated with significant cyclin B1 and securin protein accumulation after CDC23 knockdown. Moreover, the effect of CDC23 on cellular proliferation and cell cycle progression was reversed on triple knockdown studies of CDC23, cyclin B1, and securin. Our data taken together suggests CDC23 has important biologic effects on cell proliferation and cell cycle progression. The effect of CDC23 on cellular proliferation and cell cycle progression is mediated, at least in part, by cyclin B1 and securin protein levels. Therefore, we propose that CDC23 is a critical regulator of cell cycle and cell growth, and may be involved in thyroid cancer initiation and progression, and may explain the different tumor biology observed by gender.

Gene expression profiling and cancer-related pathways in type I endometrial carcinoma

INTRODUCTION

Malignant transformation of type I endometrium involves alteration in gene expression with subsequent uncontrolled proliferation of altered cells.

OBJECTIVE

The main objective of the present study was to identify the cancer-related genes and gene pathways in the endometrium of healthy and cancer patients.

MATERIALS AND METHODS

Thirty endometrial tissues from healthy and type I EC patients were subjected to total RNA isolation. The RNA samples with good integrity number were hybridized to a new version of Affymetrix Human Genome GeneChip 1.0 ST array. We analyzed the results using the GeneSpring 9.0 GX and the Pathway Studio 6.1 software. For validation assay, quantitative real-time polymerase chain reaction was used to analyze 4 selected genes in normal and EC tissue.

RESULTS

Of the 28,869 genes profiled, we identified 621 differentially expressed genes (2-fold) in the normal tissue and the tumor. Among these genes, 146 were up-regulated and 476 were down-regulated in the tumor as compared with the normal tissue (P < 0.001). Up-regulated genes included the v-erb-a erythroblastic leukemia viral oncogene homolog 3 (ErbB3), ErbB4, E74-like factor 3 (ELF3), and chemokine ligand 17 (CXCL17). The down-regulated genes included signal transducer and activator transcription 5B (STAT5b), transforming growth factor A receptor III (TGFA3), caveolin 1 (CAV1), and protein kinase C alpha (PKCA). The gene set enrichment analysis showed 10 significant gene sets with related genes (P < 0.05). The quantitative polymerase chain reaction of 4 selected genes using similar RNA confirmed the microarray results (P < 0.05).

CONCLUSIONS

Identification of molecular pathways with their genes related to type I EC contribute to the understanding of pathophysiology of this cancer, probably leading to identifying potential biomarkers of the cancer.

Assessing Population Level Genetic Instability via Moving Average

Tumoral tissues tend to generally exhibit aberrations in DNA copy number that are associated with the development and progression of cancer. Genotyping methods such as array-based comparative genomic hybridization (aCGH) provide means to identify copy number variation across the entire genome. To address some of the shortfalls of existing methods of DNA copy number data analysis, including strong model assumptions, lack of accounting for sampling variability of estimators, and the assumption that clones are independent, we propose a simple graphical approach to assess population-level genetic alterations over the entire genome based on moving average. Furthermore, existing methods primarily focus on segmentation and do not examine the association of covariates with genetic instability. In our methods, covariates are incorporated through a possibly mis-specified working model and sampling variabilities of estimators are approximated using a resampling method that is based on perturbing observed processes. Our proposal, which is applicable to partial, entire or multiple chromosomes, is illustrated through application to aCGH studies of two brain tumor types, meningioma and glioma.

RASSF7 negatively regulates pro-apoptotic JNK signaling by inhibiting the activity of phosphorylated-MKK7

Members of the Ras-association domain family (RASSF) of proteins influence apoptosis and cell cycling but little is known about the mechanisms. Here, we show that RASSF7 interacts with N-Ras and mitogen-activated protein kinase kinase 7 (MKK7) to negatively regulate c-Jun N-terminal kinase (JNK) signaling. Stress-induced JNK activation and apoptosis were markedly enhanced in cells depleted of RASSF7 or N-Ras by RNAi knockdown. An interaction with RASSF7 promoted the phosphorylated state of MKK7 but inhibited this kinase's ability to activate JNK. RASSF7 required its RA domain for both interaction with GTP-bound N-Ras and the anti-apoptotic response to stress stimuli. Following prolonged stress, however, RASSF7's anti-apoptotic effect was eliminated because of degradation of RASSF7 protein via the ubiquitin-proteasome pathway. Our results indicate that RASSF7 acts in concert with N-Ras to constitute a stress-sensitive temporary mechanism of apoptotic regulation. With initial stress, RASSF7/N-Ras promotes cell survival by inhibiting the MKK7/JNK pathway. However, with prolonged stress, RASSF7 protein undergoes degradation that allows cell death signaling to proceed. Our findings may account for the association of elevated RASSF7 with tumorigenesis.

Human RASSF7 regulates the microtubule cytoskeleton and is required for spindle formation, Aurora B activation and chromosomal congression during mitosis

RASSF7, a member of the N-terminal Ras association domain family, has increased expression in various cancers and, on the basis of our previous work in Xenopus embryos, may be a regulator of mitosis. In the present study, we address, for the first time, the role of human RASSF7 in mitosis. We demonstrate that RASSF7 is expressed in a broad range of different cell types and that this expression could be enhanced following exposure to hypoxia. Knocking down RASSF7 in human cell lines inhibited cell growth and induced defects in mitosis, including aberrant spindle formation and a failure in chromosomal congression. In order to understand the molecular basis of the defects in more detail, we analysed the activity of mitotic signalling proteins and found that activation of Aurora B did not occur in cells in which RASSF7 was knocked down. We also show that endogenous RASSF7 protein localizes to the centrosome and demonstrate using microtubule-regrowth assays that RASSF7 is an important regulator of microtubule dynamics. On the basis of these observations, we propose that, owing to its key role in regulating the microtubule cytoskeleton, RASSF7 is required for mitosis in human cells.

Joint loss of PAX2 and PTEN expression in endometrial precancers and cancer

Latent endometrial carcinoma precancers are normal-appearing endometrial glands with sporadic loss of tumor suppressor gene function such as PTEN. Progression to carcinoma is inefficient and requires additional genetic damage that creates a histologic precursor lesion called endometrial intraepithelial neoplasia (EIN). In this study, we examined loss of PAX2 expression, a gene required for embryonic uterine development, during endometrial carcinogenesis. Normal proliferative, EIN, and malignant (endometrial adenocarcinoma) endometrial tissues were immunostained for PTEN and PAX2. Proliferative samples with loss of protein in at least one gland were scored as latent precancers. EIN and cancer lesions were scored by the majority pattern. Overall prevalence and topography of joint PAX2-PTEN expression loss was examined. The prevalence of PAX2 protein loss in the sequence of normal to precancer to cancer was 36%, 71%, and 77%, respectively, and for PTEN, it was 49%, 44%, and 68%, respectively. The normal endometrial prevalence of PAX2- or PTEN-deficient latent precancers was unaffected by biopsy indication, but increased significantly with age. Coincident loss of PAX2 and PTEN expression in an individual normal endometrium was seen in 21% of patients, but usually involved different glands. Coincident loss was more common in precancers (31%) and carcinoma (55%), in which case, both markers were protein null in an overlapping clonal distribution. PAX2 and PTEN protein loss occurs independently and accumulates with increasing age in latent precancers of normal premenopausal endometrium. Loss of function of both genes in an overlapping distribution characterizes the clinical emergence of a premalignant lesion which is carried forward to carcinoma.

Down-regulation of CD9 expression and its correlation to tumor progression in B lymphomas

Histological transformation, a pivotal event in the natural history of cancers including lymphomas, is typically associated with more aggressive clinical behavior. L3055, a B lymphoma cell line of germinal center (GC) origin, is dependent on follicular dendritic cells (FDCs) for survival and proliferation, similar to GC-B cells. However, L3055 cells become less FDC-dependent after prolonged culture, which is analogous to transformation in vivo. Comparison of two L3055 subclones (i.e., the FDC-dependent indolent clone 12 and the FDC-independent aggressive clone 33) by DNA microarray revealed that CD9 was the most differentially expressed gene (P = 0.05). L3055-12 expresses high levels of CD9 while L3055-33 does not. Reduced levels or loss of CD9 expression is also observed in other CD9-positive B lymphoma cell lines. The resultant CD9-negative cells grow faster than CD9-positive cells due to their greater resistance to apoptosis. Furthermore, CD9-negative cells are less dependent on FDCs for their survival and growth compared with CD9-positive cells. CD9 down-regulation in B lymphomas appears to be controlled epigenetically, mainly through histone modifications. These findings imply that CD9 is inversely correlated with B lymphoma progression, and CD9 inactivation may play an important role in B lymphoma transformation.

Gene expression profiles and microsatellite instability in uterine corpus endometrioid adenocarcinoma

AIM

We examined corpus cancer to identify whether there are distinctive patterns of global gene expression and microsatellite instability, and to gain molecular understanding of its carcinogenesis and progression.

METHODS

Thirty endometrioid corpus cancer tissue samples (21 of G1 and nine of G2/3) were analyzed by cDNA microarray based on 637 cancer-associated genes and by a polymerase chain reaction method for microsatellite instability.

RESULT

Of the 30 cases, 10 (33%) were recognized as having microsatellite instability. In all cases, four genes were overexpressed and five genes were underexpressed. There were six microsatellite instability-specific overexpressed or high-frequency genes and 15 underexpressed or low-frequency genes. Furthermore, we identified several genes by grade analysis.

CONCLUSIONS

These results may be useful resources for the development of diagnostic assays, prognostic factors, or therapeutic targets for corpus endometrioid cancer.

Response of adult mouse uterus to early disruption of estrogen receptor-alpha signaling is influenced by Krüppel-like factor 9

Inappropriate early exposure of the hormone-responsive uterus to estrogenic compounds is associated with increased risk for adult reproductive diseases including endometrial cancers. While the dysregulation of estrogen receptor-alpha (ESR1) signaling is well acknowledged to mediate early events in tumor initiation, mechanisms contributing to sustained ESR1 activity later in life and leading to induction of oncogenic pathways remain poorly understood. We had shown previously that the transcription factor Krüppel-like factor 9 (KLF9) represses ESR1 expression and activity in Ishikawa endometrial glandular epithelial cells. We hypothesized that KLF9 functions as a tumor suppressor, and that loss of its expression enhances ESR1 signaling. Here, we evaluated the contribution of KLF9 to early perturbations in uterine ESR1 signaling pathways elicited by the administration of synthetic estrogen diethylstilbestrol (DES) to wild-type (WT) and Klf9 null (KO) mice on postnatal days (PNDs) 1-5. Uterine tissues collected at PND84 were subjected to histological, immunological, and molecular analyses. Compared with WT mice, KO mice demonstrated larger endometrial glands and lower endometrial gland numbers; DES exposure exacerbated these differences. Loss of KLF9 expression resulted in increased glandular ESR1 immunoreactivity with DES, without effects on serum estradiol levels. Quantitative RT-PCR analyses indicated altered expression of uterine genes commonly dysregulated in endometrial cancers (Akt1, Mmp9, Slpi, and Tgfbeta1) and of those involved in growth regulation (Fos, Myc, Tert, and Syk), with loss of Klf9, alone or in concert with DES. Our data support a molecular network between KLF9 and ESR1 in the uterus, and suggest that silencing of KLF9 may contribute to endometrial dysfunctions initiated by aberrant estrogen action.

The ATDC (TRIM29) protein binds p53 and antagonizes p53-mediated functions

The ataxia telangiectasia group D-complementing (ATDC) gene product, also known as TRIM29, is a member of the tripartite motif (TRIM) protein family. ATDC has been proposed to form homo- or heterodimers and to bind nucleic acids. In cell cultures, ATDC expression leads to rapid growth and resistance to ionizing radiation (IR), whereas silencing of ATDC expression decreases growth rates and increases sensitivity to IR. Although ATDC is overexpressed in many human cancers, the biological significance of ATDC overexpression remains obscure. We report here that ATDC increases cell proliferation via inhibition of p53 nuclear activities. ATDC represses the expression of p53-regulated genes, including p21 and NOXA. Mechanistically, ATDC binds p53, and this interaction is potentially fine-tuned by posttranslational acetylation of lysine 116 on ATDC. The association of p53 and ATDC results in p53 sequestration outside of the nucleus. Together, these results provide novel mechanistic insights into the function of ATDC and offer an explanation for how ATDC promotes cancer cell proliferation.

The emerging role of Krüppel-like factors in endocrine-responsive cancers of female reproductive tissues

Krüppel-like factors (KLFs), of which there are currently 17 known protein members, belong to the specificity protein (Sp) family of transcription factors and are characterized by the presence of Cys(2)/His(2) zinc finger motifs in their carboxy-terminal domains that confer preferential binding to GC/GT-rich sequences in gene promoter and enhancer regions. While previously regarded to simply function as silencers of Sp1 transactivity, many KLFs are now shown to be relevant to human cancers by their newly identified abilities to mediate crosstalk with signaling pathways involved in the control of cell proliferation, apoptosis, migration, and differentiation. Several KLFs act as tumor suppressors and/or oncogenes under distinct cellular contexts, underscoring their prognostic potential for cancer survival and outcome. Recent studies suggest that a number of KLFs can influence steroid hormone signaling through transcriptional networks involving steroid hormone receptors and members of the nuclear receptor family of transcription factors. Since inappropriate sensitivity or resistance to steroid hormone actions underlies endocrine-related malignancies, we consider the intriguing possibility that dysregulation of expression and/or activity of KLF members is linked to the pathogenesis of endometrial and breast cancers. In this review, we focus on recently described mechanisms of actions of several KLFs (KLF4, KLF5, KLF6, and KLF9) in cancers of the mammary gland and uterus. We suggest that understanding the mode of actions of KLFs and their functional networks may lead to the development of novel therapeutics to improve current prospects for cancer prevention and cure.