[Heterogeneity of epithelial ovarian carcinomas and their clinical significance]

Epithelial ovarian cancer is one of the most lethal gynecological malignant tumors despite improvement of the treatment. Recent molecular studies show that ovarian cancer is a heterogeneous disease which is reflected by different histologic types. These subtypes differ from their origin, pathogenesis and molecular alterations and can be divided in two major groups. The type I cancer (low grade) evolves from precursor lesions in a step-wise process. In contrast, the type II cancer (high grade) grows rapidly without any identifiable precursors. Among all subtypes is heterogeneity in the biological behavior which has implications in patient prognosis and treatment especially for individualized therapies in the future.

An in vivo model for the study of ovarian cancer and the persistence of characteristic mutations in xenografts

OBJECTIVE

To identify factors affecting xenograft growth of epithelial ovarian cancer (EOC) cells in nude mice and to detect characteristic mutations occurring in the xenografts following serial passage.

MATERIALS AND METHODS

A total of 64 human EOCs were subcutaneously inoculated in Balb/c nude mice in order to obtain a series of xenografts. Whole-exome sequencing was analyzed with Agilent SureSelect targeted enrichment capture system and Illumina Solexa Hiseq 2000 sequencing platform. Mutations were confirmed by comparison against the reference genome build 37.3.

RESULTS

The tumor take rate was 50% (32/64). TP53 mutation was detected in nine often Type II tumors. BRAF and CTNNB1 were not mutated in any of the samples, and PTEN mutation occurred in only one sample. The present data indicate that advanced stage serous EOCs and early stage non-serous EOCs were easy to grow in nude mice, and xenografts maintained the characteristic mutations.

CONCLUSIONS

Advanced stage serous EOCs and early stage non-serous EOCs were easy to grow in nude mice, and xenografts maintained the characteristic mutations. Xenografts in nude mice are useful in vivo models for the study of human EOCs.

Aberrant microRNA expression in endometrial carcinoma using formalin-fixed paraffin-embedded (FFPE) tissues

This study aimed to identify the candidate miRNAs in the carcinogenesis of endometrial carcinoma, and to explore whether FFPE material would be suitable for miRNA profiling. We identified the differences between miRNA expression profiles using human miRNA microarray in endometrioid endometrial adenocarcinomas (EECs) and normal endometria. Of those tested, miR-200a*, miR-200b*, miR-141, miR-182, and miR-205 were greatly enriched. The expressions of these five miRNAs were validated using quantitative real-time reverse transcription-PCR (qRT-PCR). We then performed qRT-PCR miR expression profiling in 30 FFPE specimens (20 EECs, 10 normal endometria) and re-confirmed the results of differential expression between cancer and normal tissue. Following this, we tested whether the specific inhibition of overexpressed miRNAs would alter chemosensitivity. In the in vitro cell viability assay, anti-miR200b* showed a trend toward enhanced cytotoxicity slightly in cisplatin compared to the negative control (p = 0.07). This information provided the candidate miRNAs for further confirmation of the role of miRNAs in the carcinogenesis of EECs, potentially serving as a diagnostic or therapeutic tool. FFPE specimens of endometrial tissues are suitable as a source for miRNA microarray profiling.

Down-regulation of miR-145 and miR-143 might be associated with DNA methyltransferase 3B overexpression and worse prognosis in endometrioid carcinomas

The aim of this study was to determine the clinicopathologic significance of miR-145 and miR-143 down-regulation in endometrial cancers. The microRNA profiles were analyzed by microRNA microarray. The expression levels of miR-145 and miR-143 in 73 endometrial cancers were further determined by quantitative real-time polymerase chain reaction. Potential targets of miR-145/143 were defined. The status of DNA methyltransferase 3B (DNMT3B), mutL homologs 1, and phosphatase and tensin homolog was assessed using immunohistochemistry. miR-145 and miR-143 frequently co-down-regulated in endometrial cancers, but the expression levels varied greatly between endometrioid carcinomas (ECs) and non-ECs (NECs); they were significantly lower in ECs than in NECs (P < .05). DNMT3B was defined as a potential target of miR-145/143 by Internet algorithms. In ECs, DNMT3B overexpression occurred more often in the miR-145 and miR-143 down-regulation subgroups, and the correlation between DNMT3B and miR-145 status reached statistical significance (P = .021), whereas such phenomena were not present in NECs (P > .05). In univariate analysis, the combination of DNMT3B overexpression and miR-145 or miR-143 down-regulation was more powerful in predicting shorter survival (P < .05) than use of the biomarkers individually (P > .05). In multivariate analysis, such combination was not an independent predictor of disease-free survival (P > .05). Our findings suggest that the target and function of miR-145 and miR-143 may differ in ECs versus NECs. DNMT3B might be a potential target of miR-145 and miR-143 in ECs. Furthermore, the combined miR-145 or miR-143 and DNMT3B status may have a prognostic impact on ECs.

Expression of type 2 orexin receptor in human endometrium and its epigenetic silencing in endometrial cancer

CONTEXT

Orexins A and B are neuropeptides that bind and activate 2 types of receptors. In addition to direct action in the brain, the orexinergic system has broader implications in peripheral organs, and it has been proposed to have a role in the induction of apoptosis. There are very few data on the endometrium.

OBJECTIVE

The expression and epigenetic regulation of type 2 orexin receptor (OX2R) was investigated in the human endometrium as well as in endometrial endometrioid carcinoma (EEC).

METHODS

OX2R localization was studied by immunohistochemistry in normal endometrium (n = 24) and in EEC (n = 32). The DNA methylation status of a CpG island located in the first exon of OX2R was analyzed by bisulfite sequencing in normal (n = 18), EEC (n = 34), and 3 endometrial cell lines. On the latter, mRNA expression and Western blotting as well as in vitro induction with orexin were performed.

RESULTS

Expression of the OX2R protein was detected in normal endometrial epithelia, whereas it was frequently lacking in EEC. This loss was associated with hypermethylation of OX2R in EEC in comparison with normal endometrium (median CpG methylation percentages of 48.85% and 5.85%, respectively). In cell lines, hypermethylation correlated with weak OX2R expression. Additionally, in vitro treatment of the 3 EEC cell lines with orexins A and B did not result in proliferation change

CONCLUSIONS

Altogether our data provide evidence for the epigenetic silencing of OX2R in EEC. The implication of the OX2R loss in tumoral progression remains to be elucidated.

Functional analysis of genes in regions commonly amplified in high-grade serous and endometrioid ovarian cancer

PURPOSE

Ovarian cancer has the highest mortality rate of all the gynecologic malignancies and is responsible for approximately 140,000 deaths annually worldwide. Copy number amplification is frequently associated with the activation of oncogenic drivers in this tumor type, but their cytogenetic complexity and heterogeneity has made it difficult to determine which gene(s) within an amplicon represent(s) the genuine oncogenic driver. We sought to identify amplicon targets by conducting a comprehensive functional analysis of genes located in the regions of amplification in high-grade serous and endometrioid ovarian tumors.

EXPERIMENTAL DESIGN

High-throughput siRNA screening technology was used to systematically assess all genes within regions commonly amplified in high-grade serous and endometrioid cancer. We describe the results from a boutique siRNA screen of 272 genes in a panel of 18 ovarian cell lines. Hits identified by the functional viability screen were further interrogated in primary tumor cohorts to determine the clinical outcomes associated with amplification and gene overexpression.

RESULTS

We identified a number of genes as critical for cellular viability when amplified, including URI1, PAK4, GAB2, and DYRK1B. Integration of primary tumor gene expression and outcome data provided further evidence for the therapeutic use of such genes, particularly URI1 and GAB2, which were significantly associated with survival in 2 independent tumor cohorts.

CONCLUSION

By taking this integrative approach to target discovery, we have streamlined the translation of high-resolution genomic data into preclinical in vitro studies, resulting in the identification of a number of genes that may be specifically targeted for the treatment of advanced ovarian tumors.

PTEN loss and HOXA10 expression are associated with ovarian endometrioid adenocarcinoma differentiation and progression

Epithelial ovarian cancer is a heterogeneous disease that is subdivided into five major histotypes but the mechanisms driving their differentiation are not clear. Mutations in adenomatous polyposis coli (APC) and β-catenin are commonly observed in the human ovarian endometrioid adenocarcinoma (OEA) patients. However, the mechanisms subsequent to APC deletion in ovarian tumorigenesis have not been well characterized. We have conditionally deleted APC in the murine ovarian surface epithelium (OSE) and showed that its loss leads to development of epithelial inclusion cysts. High-grade OEAs with tightly packed villoglandular histology were observed in older APC-deleted mice. Phosphatase and tensin homolog (PTEN) expression was elevated in the early lesions but lost after progression to the more advanced tumors. Knockdown of APC or expression of a gain-of-function β-catenin similarly induced human OSE cells to develop tumors with endometrioid histology in xenografts. Expression of HOXA10 was induced in both the advanced APC-deleted murine tumors and in the tumor xenografts of human OSE cells with knocked-down APC. These results show that reduced APC activity is sufficient to induce formation of epithelial inclusion cysts and support OEA development and suggest that induced HOXA10 expression and loss of PTEN are key mechanisms driving endometrioid histotype differentiation and progression.

Molecular imaging reveals a role for AKT in resistance to cisplatin for ovarian endometrioid adenocarcinoma

PURPOSE

Ovarian cancer is the fifth leading cause of cancer-related deaths among American women. Platinum-based chemotherapy, such as cisplatin, represents the standard-of-care for ovarian cancer. However, toxicity and acquired resistance to cisplatin have proven challenging in the treatment of patients with ovarian cancer.

EXPERIMENTAL DESIGN

Using a genetically engineered mouse model of ovarian endometrioid adenocarcinoma (OEA) in combination with molecular-imaging technologies, we studied the activation of the AKT serine/threonine kinase in response to long-term cisplatin therapy.

RESULTS

Treatment of cells in culture and tumor-bearing animals with cisplatin resulted in activation of AKT, a key mediator of cell survival. On the basis of these results, we investigated the therapeutic use of AKT inhibition in combination with cisplatin, which resulted in enhanced and prolonged induction of apoptosis and in significantly improved tumor control as compared with either agent alone.

CONCLUSION

These results provide an impetus for clinical trials using combination therapy. To facilitate these trials, we also show the use of diffusion-weighted MRI as an imaging biomarker for evaluation of therapeutic efficacy in OEA.

Variants in DENND1A and LHCGR are associated with endometrioid adenocarcinoma

OBJECTIVE

The aim of this study was to explore the polycystic ovary syndrome (PCOS) related single nucleotide polymorphisms (SNPs) rs13405728 (in gene LHCGR), rs13429458 (in gene THADA) and rs2479106 (in gene DENND1A) in women with endometrial carcinoma.

METHODS

We conducted a case-control study comprising 96 Han Chinese women with endometrial carcinoma, and 192 healthy controls. SNPs rs13405728, rs13429458 and rs2479106 were genotyped by polymerase chain reaction (PCR) and direct sequencing. The effects of body mass index (BMI) and age were evaluated using an unconditional logistic regression model adjusted for potential confounders.

RESULTS

The allele frequencies of SNPs rs2479106 and rs13405728 were significantly different (P<0.05) between endometrial carcinoma group and control group, and the difference was especially significant in the subgroup of endometrioid adenocarcinoma. Genotyping analysis showed that allele G in rs2479106 and allele A in rs13405728 could confer risk to endometrioid adenocarcinoma.

CONCLUSIONS

Our results suggest that SNPs rs2479106 in gene DENND1A and rs13405728 in gene LHCGR are associated with endometrioid adenocarcinoma.

PRKAR1A gene analysis and protein kinase A activity in endometrial tumors

PRKAR1A codes for the type 1a regulatory subunit (RIα) of the cAMP-dependent protein kinase A (PKA), an enzyme with an important role in cell cycle regulation and proliferation. PKA dysregulation has been found in various tumors, and PRKAR1A-inactivating mutations have been reported in mostly endocrine neoplasias. In this study, we investigated PKA activity and the PRKAR1A gene in normal and tumor endometrium. Specimens were collected from 31 patients with endometrial cancer. We used as controls 41 samples of endometrium that were collected from surrounding normal tissues or from women undergoing gynecological operations for other reasons. In all samples, we sequenced the PRKAR1A-coding sequence and studied PKA subunit expression; we also determined PKA activity and cAMP binding. PRKAR1A mutations were not found. However, PKA regulatory subunit protein levels, both RIα and those of regulatory subunit type 2b (RIIβ), were lower in tumor samples; cAMP binding was also lower in tumors compared with normal endometrium (P<0.01). Free PKA activity was higher in tumor samples compared with that of control tissue (P<0.01). There are significant PKA enzymatic abnormalities in tumors of the endometrium compared with surrounding normal tissue; as these were not due to PRKAR1A mutations, other mechanisms affecting PKA function ought to be explored.

Molecular links between endometriosis and cancer

Endometriosis is the leading cause of morbidity among premenopausal women affecting about 1 in 10 females. The features shared by endometriosis and cancer include the ability to evade apoptosis, the stem cell-like ability and angiogenic potential. As such characteristics are encoded by the cell's genetic constitution, acquired mutations are responsible for the malignant transformation of endometriosis. Indeed, a number of tumour-suppressor genes and proto-oncogenes, such as protein 53 (P53) and B-cell lymphoma 2 (BCL-2) respectively, are mutated and as a result differentially expressed between endometriotic and malignant tissue associated with endometriosis. Moreover, cytokines and macrophages, both of which are inflammatory mediators have been implicated in the transformation process. The angiogenic properties possessed by cancer arising from endometriosis signifies a bad prognosis, while the stem cell-like activity possessed by both endometriosis and cancer has been attributed to the effect of oestrogen. A number of differences between endometriosis and cancer are found at the molecular level. Considering the link between these two pathologies, the three components which fuel the malignant transformation of endometriosis can be embodied in the endometriosis-induced carcinoma (EIC) triangle which shows the intricate relationship between endocrinologic, immunologic and genetic components.

Endometrial miR-181a and miR-98 expression is altered during transition from normal into cancerous state and target PGR, PGRMC1, CYP19A1, DDX3X, and TIMP3

CONTEXT

Evidence suggests that a number of microRNA (miRNA) are aberrantly expressed in endometrial disorders with potential posttranscriptional regulation of their specific target genes, including ovarian steroid receptors.

OBJECTIVES

Our objective was to assess the endometrial expression of miR-98 and miR-181a and their respective target genes, progesterone (P4) receptor membrane component 1 (PGRMC1) and P4 receptor (PGR).

DESIGN, SETTING, AND PATIENTS

We evaluated tissue expression and in vitro regulation at an academic university medical center in endometrial biopsies and endometrial tissues from follicular and luteal phases with and without exposure to hormonal therapies and grade I-III endometrial cancer (n = 52).

INTERVENTIONS

INTERVENTIONS included endometrial biopsies and in vitro transfection.

MAIN OUTCOME MEASURES

We evaluated expression and function of miR-98 and miR-181a.

RESULTS

Aberrant expression of miR-98 and miR-181a is associated with endometrial transition from normal into cancerous states, which to some extent is influenced by hormonal milieu, and exhibited an inverse relationship with PGMRC1 and PGR expression, respectively. Treatments of Ishikawa cells with 17β-estradiol, P4, or medroxyprogesterone acetate had limited effects on miR-98, miR-181a, and PGRMC1 expression, whereas 17β-estradiol treatment increased PGR expression. In Ishikawa cells, gain of function of miR-98 repressed PGRMC1 and CYP19A1, and miR-181a repressed PGR, DDX3X, and TIMP3 at mRNA and protein levels through direct interactions with their respective 3'-untranslated regions and CCNE1 through miR-181a-induced DDX3X repression, with miR-98 reducing the rate of cell proliferation as compared with controls.

CONCLUSION

miR-98 and miR-181a through their regulatory functions on PGRMC1, PGR, CYP19A1, TIMP3, and DDX3X expression may influence a wide range of endometrial cellular activities during normal menstrual cycle and transition into disease states, including endometrial cancer.

[Ovarian cancer--modern approach to its origin and histogenesis]

Ovarian cancers (OC) belong to a heterogeneous group of pathologies and are traditionally classified with regard to histological type and degree of differentiation. OC was hypothesized to originate from ovarian surface epithelium (OSE) and inclusion cysts epithelium (IC). Unfortunately this theory was never supported by any clinical or molecular evidence linking carcinogenesis with OSE and was refuted. OC subtypes demonstrate morphologic features that resemble Müllerian duct-derived epithelia of the genital tract. Investigations of the HOX gene family Müllerian epithelial differentiation markers, confirmed the HOX genes expression in many subtypes of OC but not in OSE. The first step towards connecting OC origin with other than OSE genital tract structures were epidemiological observations indicating a minor OC risk after tubal ligation in women with the BRCA mutation. The first in situ carcinoma was found in the Fallopian tube fimbriae. Further research confirmed the same mechanism in sporadic OC. Endometriosis and endometrium cells may be a highly probable place of endometrioid OC initiation. Mucinous types share common futures with gastrointestinal tract cancers and there one needs to search for their precursors. Clear cell carcinoma may arise from glandular epithelium of endocervix or from endometrioid foci. The new classification of OC was proposed in 2004, suggesting to divide all OC into two types: I and II. Type II includes serous and endometrioid G3 subtypes, carcinosarcomas and undifferentiated OC. They are responsible for 75% of OC morbidity identified usually in FIGO stages Ill or IV, have poor prognosis and relapse early The remaining hystiotypes, with better prognosis and earlier FIGO stages at time of diagnosis, were classified as type I. Serous and endometrioid poorly differentiated ovarian cancers demonstrate mutation in TP53 gene (type II) and highly differentiated ones, generally in BRAS and KRAS genes (type I). The differences in molecular pathways also confirm different patterns of carcinogenesis of both OC types. Modern approach to OC histogenesis and origin emphasizes the necessity to verify OC screening, detection and treatment methods.

Prognostic importance of DNA ploidy and DNA index in stage I and II endometrioid adenocarcinoma of the endometrium

BACKGROUND

We evaluated the prognostic importance of DNA ploidy in stage I and II endometrioid adenocarcinoma (EAC) of the endometrium with a focus on DNA index.

PATIENTS AND METHODS

High-resolution DNA ploidy analysis was carried out in tumor material from 937 consecutive patients with International Federation of Gynecology and Obstetrics (FIGO) stage I and II EAC of the endometrium.

RESULTS

Patients with diploid (N = 728), aneuploid tumor with DNA index ≤ 1.20 (N = 118), aneuploid tumors with DNA index >1.20 (N = 39) and tetraploid tumor (N = 52) had 5-year recurrence rates 8%, 14%, 20% and 12%, respectively. Patients with aneuploid tumor with DNA index >1.20 had a poorer 5-year progression-free survival (67%) and overall survival (72%) compared with the patients with aneuploid tumor with DNA index ≤ 1.20 (81% and 89%, respectively). Aneuploid tumors with DNA index ≤ 1.20 relapsed mainly in the vagina and pelvis, whereas aneuploid tumors with DNA index >1.20 relapsed predominantly outside pelvis.

CONCLUSIONS

The recurrence risk for the patients with aneuploid tumor is higher than the patients with diploid tumor in EAC of the endometrium. Based on DNA index with cut-off 1.20, aneuploid tumors can be separated into two subgroups with different recurrence pattern and survival.

HNF1B and endometrial cancer risk: results from the PAGE study

We examined the association between HNF1B variants identified in a recent genome-wide association study and endometrial cancer in two large case-control studies nested in prospective cohorts: the Multiethnic Cohort Study (MEC) and the Women's Health Initiative (WHI) as part of the Population Architecture using Genomics and Epidemiology (PAGE) study. A total of 1,357 incident cases of invasive endometrial cancer and 7,609 controls were included in the analysis (MEC: 426 cases/3,854 controls; WHI: 931 cases/3,755 controls). The majority of women in the WHI were European American, while the MEC included sizable numbers of African Americans, Japanese and Latinos. We estimated the odds ratios (ORs) per allele and 95% confidence intervals (CIs) of each SNP using unconditional logistic regression adjusting for age, body mass index, and four principal components of ancestry informative markers. The combined ORs were estimated using fixed effect models. Rs4430796 and rs7501939 were associated with endometrial cancer risk in MEC and WHI with no heterogeneity observed across racial/ethnic groups (P ≥ 0.21) or between studies (P ≥ 0.70). The OR(per allele) was 0.82 (95% CI: 0.75, 0.89; P = 5.63 × 10(-6)) for rs4430796 (G allele) and 0.79 (95% CI: 0.73, 0.87; P = 3.77 × 10(-7)) for rs7501939 (A allele). The associations with the risk of Type I and Type II tumors were similar (P ≥ 0.19). Adjustment for additional endometrial cancer risk factors such as parity, oral contraceptive use, menopausal hormone use, and smoking status had little effect on the results. In conclusion, HNF1B SNPs are associated with risk of endometrial cancer and that the associated relative risks are similar for Type I and Type II tumors.

Prognostic importance of selected molecular immunohistochemical markers and DNA ploidy in endometrial cancer

The aim of the study was the analysis of the new molecular genetic immunomarkers (p53, c-erbB-2, Ki 67, bcl-2) hormonal receptors (ER, PR) and ploidy disturbances and their relation to the most important prognostic factors for endometrial cancer. The study group consisted of 135 endometrial cancer patients. Biopsies of the tumours obtained at operations were routinely histopathologically examined. Subsequenly, the immunohistochemical tumour markers were determined. The same biopsies were examined by microdissection and flow cytometric ploidy analysis and karyotyping. The findings were compared with the most important prognostic factors for endometrial cancer, mainly with clinical stage of the disease and grade.

RESULTS

High expression of p53, Ki 67, c-erbB-2 and low rate of progesterone receptors was found in the prognostically unfavourable group (G 3). Aneuploidy was found in 72% in the group of poorly differentiated endometrial cancers (G 3) in contrast to 27% in the group of G1 and G2 tumours, but this difference was not statistically significant.

CONCLUSIONS

Identification of p53, Ki 67, c-erbB-2, PR and determination of DNA ploidy is a useful tool to specify a group of prognostically unfavourable patients.

[Significance of phosphoinositide 3 kinase/AKT pathway alterations in endometrial carcinoma]

OBJECTIVE

To investigate the clinicopathologic and prognostic implications of phosphoinositide 3 kinase (PI3K)/AKT pathway alterations in endometrial cancers of Chinese women.

METHODS

The expression of PTEN, p-AKT, and ER/PR was assessed in 71 cases of endometrial carcinoma by immunohistochemistry (EnVision method). The PIK3CA mutation at exon 9 and exon 20 was analyzed by PCR and direct sequencing in 34 tumors.

RESULTS

(1) Of the 71 cases of endometrial carcinoma, 65 cases were endometrioid adenocarcinoma (EEC) and 6 cases were nonendometrioid adenocarcinoma (NEEC). PTEN loss of expression was found in 63.4% (45/71) of tumors, and more commonly occurred in EEC (66.2%, 43/65) than that in NEEC (2/6, P = 0.18). Patients with PTEN loss in their tumors (45 cases) had a better survival than those without (26 cases, P = 0.07). In ER negative subgroup, the patients with PTEN loss of expression (12 cases) had longer survival than those with normal PTEN expression (7 cases; P = 0.04). (2) The frequency of PIK3CA mutation was 41.2% (14/34) with a hot mutation spot at T544 in exon 9. PIK3CA mutations more commonly occurred in EEC (44.8%, 13/29) than in NEEC (1/5, P > 0.05). The mutations at exon 9 more commonly occurred in EEC, well- and moderately-differentiated EEC, and tumors at early stage (P > 0.05). On the contrary, in tumors at early stages, the frequency of mutations in exon 20 (14.3%, 4/28) was significantly lower than that at late stages (4/6, P = 0.01). (3) p-AKT was positive in 59.2% (42/71) of tumors that were more frequently found in EEC (60.0%, 39/65) than that in NEEC (3/6, P = 0.68). However, the significant difference of p-AKT expression was found between well- and moderately-differentiated EEC (75.0%, 21/28; 53.6%, 15/28) and poorly-differentiated EEC (3/9, P = 0.02). Moreover, p-AKT expression was significantly correlated with positive ER (r = 0.339, P = 0.00).

CONCLUSIONS

Endometrial carcinoma patients with loss of PTEN and p-AKT positivity have a favorable prognosis. PIK3CA mutations at exon 9 or 20 may have different impact on the prognosis. The function of PTEN loss and p-AKT expression may vary according to different hormone status.

[Epigenetic inactivation of SPOCK2 in the malignant transformation of ovarian endometriosis]

OBJECTIVE

To investigate epigenetic inactivation of SPOCK2 gene in the malignant transformation of ovarian endometriosis (EM) by comparing the methylation status and protein expression of SPOCK2 gene in the malignant tissues, ectopic endometria and the eutopic endometria of endometriosis.

METHODS

From Jan. 2005 to Jan. 2011, 22 paraffin-embedded specimens diagnosed as malignant transformation of ovarian endometriosis (EAOC) including 11 cases with ovarian endometrioid carcinoma, 8 cases with clear cell carcinoma, 2 cases with serous cystadenocarcinoma and 1 case with mucous cystoadenocarcinoma matched with 22 cases with ovarian endometriosis and 16 cases with normal endometrium form cervical intraepithelial neoplasia(CIN) patients as controls in Department of Obstetrics and Gynecology of Shengjing Hospital. Twenty-two malignant tissues, 15 ectopic endometria and 10 eutopic endometria were captured by microdissection in EAOC group; 22 ectopic endometria and 17 eutopic endometria were captured in EM group; 22 endometrium were captured in the NE group. The methylation statue of SPOCK2 was determined by combined bisulfite restriction analysis, and the protein expression of SPOCK2 was evaluated by immunohistochemistry.

RESULTS

(1) Methylation of SPOCK2: in the EAOC group, the frequency of SPOCK2 hypermethylation in malignant tissue was 45% (10/22), which was significantly higher than 1/15 in the ectopic endometrium (P < 0.05). There was no statistical difference of the frequency of SPOCK2 hypermethylation in ectopic endometrium in the EAOC group (1/15) and EM group (5%, 1/22) (P > 0.05). (2) SPOCK2 protein: the loss rate of SPOCK2 was 44% (11/22) in malignant tissue in EAOC group, which were significantly higher than 2/15 of in ectopic endometrium of EAOC (P < 0.05). However, there was no remarkable difference in loss rate of SPOCK2 protein between ectopic endeometrium of EAOC and endometrium of EM [2/15 vs. 5% (1/22), P > 0.05]. No significantly difference in loss rate of SPOCK2 in eutopic endometrium was observed among three groups (P > 0.05). (3) The abnormal methylation of SPOCK2 could lead to loss expression of protein (P < 0.05).

CONCLUSION

Epigenetic inactivation of SPOCK2 gene is involved in the malignant transformation of ovarian endometriosis.

PIK3R1 (p85α) is somatically mutated at high frequency in primary endometrial cancer

Phosphoinositide 3-kinase (PI3K) is an important therapeutic target. Mutations in PIK3CA, which encodes p110α, the catalytic subunit of PI3K, occur in endometrioid endometrial cancers (EEC) and nonendometrioid endometrial cancers (NEEC). The goal of this study was to determine whether PIK3R1, which encodes p85α, the inhibitory subunit of PI3K, is mutated in endometrial carcinoma. We carried out exonic sequencing of PIK3R1 from 42 EECs and 66 NEECs. The pattern of PIK3R1 mutations was compared with the patterns of PIK3CA, PTEN, and KRAS mutations. The biochemical effect of seven PIK3R1 mutations was examined by stable expression in U2OS cells, followed by coimmunoprecipitation analysis of p110α, and Western blotting of phospho-AKT(Ser473) (p-AKT(Ser473)). We found that PIK3R1 was somatically mutated in 43% of EECs and 12% of NEECs. The majority of mutations (93.3%) were localized to the p85α-nSH2 and -iSH2 domains. Several mutations were recurrent. PIK3R1 mutations were significantly (P = 0.0015) more frequent in PIK3CA-wild type EECs (70%) than in PIK3CA mutant EECs (18%). Introduction of wild-type p85α into U2OS cells reduced the level of p-AKT(Ser473) compared with the vector control. Five p85α mutants, p85αdelH450-E451, p85αdelK459, p85αdelY463-L466, p85αdelR574-T576, and the p85αN564D positive control, were shown to bind p110α and led to increased levels of p-AKT(Ser473). The p85αR348X and p85αK511VfsX2 mutants did not bind p110α and showed no appreciable change in p-AKT(Ser473) levels. In conclusion, our study has revealed a new mode of PI3K alteration in primary endometrial tumors and warrants future studies to determine whether PIK3R1 mutations correlate with clinical outcome to targeted therapies directed against the PI3K pathway in EEC and NEEC.

Association of CYP1B1 gene polymorphisms and the positive expression of estrogen alpha and estrogen beta with endometrial cancer risk

To investigate the relationship between the CYP1B1 L432V polymorphism, ERalpha and ERbeta positivities and the incidence of endometrial cancer. The relationship between CYP1B1 L432V polymorphism, ERalpha and ERbeta positivities and endometrial cancer was investigated using the allele-specific polymerase chain reaction method to analyze gene polymorphism in exon 3 codon 432 (C-G) of CYP1B1. Our results are as follows: in endometrial cancer cases the prevalence rates of CYP1B1 L432V genotypes C/C, C/G, and G/G were 47.2%, 36.1%, and 16.7%, respectively, and 68.8%, 23.8% and 7.5% in the control group, respectively. The frequencies of CYP1B1 C and G alleles were 65.3% and 34.7% in endometrial cancer patients and 80.6% and 19.4% in the control group. A significant difference was found in the genotype distributions or allele frequencies of CYP1B1 L432V polymorphism between the two groups (p < 0.05). Compared with wild-type C/C, the susceptibility of endometrial cancer with homozygotic mutation G/G and heterozygotic mutation C/G increased by 3.235 (95%CI 1.111-9.425) and 2.214 (95% CI 1.067-4.593). Moveover, the positive expression of ERalpha in genotypes G/G and C/G was higher than in the wild genotype C/C (p < 0.05). In conclusion, allelic polymorphism of CYP1B1 L432V increases the risk of endometrial cancer and has a positive correlation with ERalpha expression.

A study of the methylation status of opioid binding protein/cell adhesion molecule-like gene in ovarian cancer using nested methylation-specific polymerase chain reaction detection

BACKGROUND

The goal was to improve the methylation-specific PCR (MSP) method and investigate the methylation status of the OPCML gene in carcinoma tissues from ovarian cancer patients.

METHODS

MSP and nested MSP methods were used to examine the methylation status of the OPCML gene promoter in ovarian cancer, borderline tumor, and normal ovary tissues.

RESULTS

Methylation of the OPCML gene was detected in 58.3% (14/24) and 83.3% (20/24) of the specimens from ovarian cancer patients using MSP and nested MSP methods, respectively. No methylation was observed in normal ovarian tissues using either method.

CONCLUSIONS

The modified nested MSP method showed better sensitivity. The methylation of the OPCML gene was significantly higher in ovarian cancer than in normal tissue. The detection of OPCML gene methylation could serve as one of the molecular markers for the diagnosis of ovarian cancer.

Microarray analysis reveals distinct gene expression profiles among different tumor histology, stage and disease outcomes in endometrial adenocarcinoma

BACKGROUND

Endometrial cancer is the most common gynecologic malignancy in developed countries and little is known about the underlying mechanism of stage and disease outcomes. The goal of this study was to identify differentially expressed genes (DEG) between late vs. early stage endometrioid adenocarcinoma (EAC) and uterine serous carcinoma (USC), as well as between disease outcomes in each of the two histological subtypes.

METHODOLOGY/PRINCIPAL FINDING

Gene expression profiles of 20 cancer samples were analyzed (EAC = 10, USC = 10) using the human genome wide illumina bead microarrays. There was little overlap in the DEG sets between late vs. early stages in EAC and USC, and there was an insignificant overlap in DEG sets between good and poor prognosis in EAC and USC. Remarkably, there was no overlap between the stage-derived DEGs and the prognosis-derived DEGs for each of the two histological subtypes. Further functional annotation of differentially expressed genes showed that the composition of enriched function terms were different among different DEG sets. Gene expression differences for selected genes of various stages and outcomes were confirmed by qRT-PCR with a high validation rate.

CONCLUSION

This data, although preliminary, suggests that there might be involvement of distinct groups of genes in tumor progression (late vs. early stage) in each of the EAC and USC. It also suggests that these genes are different from those involved in tumor outcome (good vs. poor prognosis). These involved genes, once clinically verified, may be important for predicting tumor progression and tumor outcome.

Microarray analysis reveals distinct gene expression profiles among different tumor histology, stage and disease outcomes in endometrial adenocarcinoma

Background

Endometrial cancer is the most common gynecologic malignancy in developed countries and little is known about the underlying mechanism of stage and disease outcomes. The goal of this study was to identify differentially expressed genes (DEG) between late vs. early stage endometrioid adenocarcinoma (EAC) and uterine serous carcinoma (USC), as well as between disease outcomes in each of the two histological subtypes.

Methodology/Principal Finding

Gene expression profiles of 20 cancer samples were analyzed (EAC = 10, USC = 10) using the human genome wide illumina bead microarrays. There was little overlap in the DEG sets between late vs. early stages in EAC and USC, and there was an insignificant overlap in DEG sets between good and poor prognosis in EAC and USC. Remarkably, there was no overlap between the stage-derived DEGs and the prognosis-derived DEGs for each of the two histological subtypes. Further functional annotation of differentially expressed genes showed that the composition of enriched function terms were different among different DEG sets. Gene expression differences for selected genes of various stages and outcomes were confirmed by qRT-PCR with a high validation rate.

Conclusion

This data, although preliminary, suggests that there might be involvement of distinct groups of genes in tumor progression (late vs. early stage) in each of the EAC and USC. It also suggests that these genes are different from those involved in tumor outcome (good vs. poor prognosis). These involved genes, once clinically verified, may be important for predicting tumor progression and tumor outcome.

Synchronous ovarian endometrioid adenocarcinoma with a functioning stroma and endometrial endometrioid adenocarcinoma by different loss of heterozygosity findings

PURPOSE

Mucinous epithelial ovarian tumors generally have estrogenic stroma, although the frequency of endometrioid adenocarcinoma with functioning stroma is very low. And while synchronous development of carcinomas in the endometrium and ovaries is a fairly common phenomenon, the distinction of a single clonal tumor with metastasis from two independent primary tumors may present a diagnostic challenge. We present a rare case of a 31-year-old woman with endometrioid adenocarcinoma of the ovary with functioning stroma and endometrial endometrioid adenocarcinoma who showed symptoms of virilization. Her preoperative levels of serum testosterone and estradiol were as high as 553 ng/dL and 177 pg/mL, respectively, and her serum gonadotropin levels were suppressed. After surgery, the serum levels of testosterone and estradiol decreased and that of follicle-stimulating hormone increased.

METHODS

To develop a mean of differentiating a single tumor with metastasis from synchronous primary ovarian and endometrial cancers, we performed a microsatellite analysis. Twenty-five dinucleotide microsatellite markers were selected, and microsatellite analysis was performed by a high-resolution method using fluorescence-labeled polymerase chain reaction and laser scanning.

RESULTS

In this case, both ovarian carcinoma and endometrial carcinoma demonstrated loss of heterozygosity (LOH). However, the LOH findings of the ovarian tumor and endometrial tumor were different.

CONCLUSIONS

Loss of heterozygosity analysis may be helpful to differentiate synchronous primary ovarian and endometrial cancers from a single tumor with metastasis.

Wnt/Β-catenin and sex hormone signaling in endometrial homeostasis and cancer

A delicate balance between estrogen and progestagen signaling underlies proper functioning of the female reproductive tract and, in particular, the monthly re- and degenerative phases characteristic of the menstrual cycle. Here, we propose that the canonical Wnt/β-catenin signaling pathway may underlie this finely tuned hormonal equilibrium in endometrial homeostasis and, upon its constitutive activation, lead to neoplastic transformation of the endometrium. During the menstrual cycle, estradiol will enhance Wnt/β-catenin signaling in the proliferative phase, while progesterone inhibits Wnt/β-catenin signaling, thus restraining estrogens' proliferative actions, during the secretory phase. In case of enhanced or unopposed estrogen signaling, constitutive activation of Wnt/β-catenin signaling will trigger endometrial hyperplasia, which may develop further into endometrial cancer.

ARID1A mutations in endometriosis-associated ovarian carcinomas

BACKGROUND

Ovarian clear-cell and endometrioid carcinomas may arise from endometriosis, but the molecular events involved in this transformation have not been described.

METHODS

We sequenced the whole transcriptomes of 18 ovarian clear-cell carcinomas and 1 ovarian clear-cell carcinoma cell line and found somatic mutations in ARID1A (the AT-rich interactive domain 1A [SWI-like] gene) in 6 of the samples. ARID1A encodes BAF250a, a key component of the SWI–SNF chromatin remodeling complex. We sequenced ARID1A in an additional 210 ovarian carcinomas and a second ovarian clear-cell carcinoma cell line and measured BAF250a expression by means of immunohistochemical analysis in an additional 455 ovarian carcinomas.

RESULTS

ARID1A mutations were seen in 55 of 119 ovarian clear-cell carcinomas (46%), 10 of 33 endometrioid carcinomas (30%), and none of the 76 high-grade serous ovarian carcinomas. Seventeen carcinomas had two somatic mutations each. Loss of the BAF250a protein correlated strongly with the ovarian clear-cell carcinoma and endometrioid carcinoma subtypes and the presence of ARID1A mutations. In two patients, ARID1A mutations and loss of BAF250a expression were evident in the tumor and contiguous atypical endometriosis but not in distant endometriotic lesions.

CONCLUSIONS

These data implicate ARID1A as a tumor-suppressor gene frequently disrupted in ovarian clear-cell and endometrioid carcinomas. Since ARID1A mutation and loss of BAF250a can be seen in the preneoplastic lesions, we speculate that this is an early event in the transformation of endometriosis into cancer. (Funded by the British Columbia Cancer Foundation and the Vancouver General Hospital–University of British Columbia Hospital Foundation.).

Isomorph expression of BAG-1 gene, ER and PR in endometrial cancer

BACKGROUND

BAG-1 isomorphs are regulating proteins with antiapoptotic action in endometrium. ERa and PRA isomorphs seem to have an important role in endometrial cancer.

PATIENTS AND METHODS

We investigated the expression of BAG-1, ERa and PRA isomorphs in endometrioid adenocarcinoma and we correlated them with clinicopathological findings of the tumor. Fresh endometrial tissues were obtained from 33 patients with endometrial carcinoma and 191 paraffin-embedded tissues were analyzed by real-time PCR and immunochemistry for BAG-1, ER and PR.

RESULTS

BAG-1 protein is expressed in both nucleus and cytoplasm. Grade 3 tumors were considered to have the highest intensity. Only 4 out of 79 samples showed intense expression of ERa, while 37 samples out of 72 samples strongly expressed PRA.

CONCLUSION

BAG-1 nuclear isomorph appeared more frequently in grade 2 tumors than in grade 1 and 3 tumors, and the cytoplasmatic isomorph was expressed more strongly than the nuclear one.

Methylation profiles of endometrioid and serous endometrial cancers

Promoter methylation is a gene- and cancer type-specific epigenetic event that plays an important role in tumour development. As endometrioid (endometrioid endometrial carcinoma, EEC) and serous endometrial cancers (uterine papillary serous carcinoma, UPSC) exhibit different clinical, histological and molecular genetic characteristics, we hypothesized that these differences may be reflected in epigenetic phenomena as well. Identification of a panel of methylation biomarkers could be helpful in a correct histological classification of these two subtypes, which solely on the basis of morphology is not always easy. Methylation-specific multiplex ligation-dependent probe amplification was used to assess the extent of promoter methylation of different tumour suppressor genes in EEC and UPSC. Methylation results were correlated with histology and survival. The median cumulative methylation index of all genes was significantly higher in EEC (124) than in UPSC (93) (P<0.001). Promoter methylation of CDH13 and MLH1 was more frequently present in EEC, while CDKN2B and TP73 were more frequently methylated in UPSC. Almost 90% of EEC and 70% of UPSC could be predicted by CDH13 and TP73. In EEC, methylation of MLH1 was associated with a shorter disease-free survival (DFS; P<0.0001) and overall survival (OS; P=0.005). In a multivariate model, MLH1 methylation emerged as an additional prognostic factor to stage for DFS (P=0.002). In conclusion, promoter methylation is more common in EEC than UPSC. A panel of methylation biomarkers could be useful to distinguish between the two histological subtypes of endometrial cancer. Furthermore, methylation of MLH1 may have prognostic value in EEC.

[Expression of EVEC in ovarian carcinoma and its biological significance]

OBJECTIVE

To investigate the expression of EVEC in ovarian carcinoma and explore its biological significance.

METHODS

The expression of EVEC in 22 specimens of normal ovarian tissues and 63 specimens of ovarian cancers was detected by RT-PCR and Western blotting analysis, respectively.

RESULTS

RT-PCR showed that the expression level of EVEC in stage I-II ovarian cancer (0.199 ± 0.014) was significantly higher than that in stage III-IV ovarian cancer (0.155 ± 0.015, P < 0.05), and significantly lower than that in normal ovarian tissues (0.415 ± 0.055, P < 0.05). There was no significant difference between the expression levels of EVEC in primary sites and that in corresponding metastatic sites of ovarian cancer (P > 0.05). Furthermore, the results of Western blot also showed that the protein expression level of EVEC in stage I-II ovarian cancer was also significantly lower than that in normal ovarian tissues (0.179 ± 0.026 vs. 0.543 ± 0.032, P < 0.05), and higher than that in stage III-IV ovarian cancer (0.179 ± 0.026 vs. 0.115 ± 0.023, P < 0.05). The EVEC expression level in the epiploic metastasis of stage I-II ovarian cancer was significantly higher than that of stage III-IV ovarian cancer (0.201 ± 0.028 vs. 0.101 ± 0.037, P < 0.05). The expression of EVEC in ovarian carcinoma had no correlation with age, pathologic classification and histological grade (P > 0.05).

CONCLUSIONS

EVEC is closely related with carcinoma metastasis. The expression of EVEC in ovarian cancer and its metastatic sites was remarkably decreased. EVEC may play a negative role in the development and metastasis of ovarian cancer and may be a valuable marker in estimation of the prognosis for patients.

Vascular endothelial growth factor-D over-expressing tumor cells induce differential effects on uterine vasculature in a mouse model of endometrial cancer

BACKGROUND

It has been hypothesised that increased VEGF-D expression may be an independent prognostic factor for endometrial cancer progression and lymph node metastasis; however, the mechanism by which VEGF-D may promote disease progression in women with endometrial cancer has not been investigated. Our aim was to describe the distribution of lymphatic vessels in mouse uterus and to examine the effect of VEGF-D over-expression on these vessels in a model of endometrial cancer. We hypothesised that VEGF-D over-expression would stimulate growth of new lymphatic vessels into the endometrium, thereby contributing to cancer progression.

METHODS

We initially described the distribution of lymphatic vessels (Lyve-1, podoplanin, VEGFR-3) and VEGF-D expression in the mouse uterus during the estrous cycle, early pregnancy and in response to estradiol-17beta and progesterone using immunohistochemistry. We also examined the effects of VEGF-D over-expression on uterine vasculature by inoculating uterine horns in NOD SCID mice with control or VEGF-D-expressing 293EBNA tumor cells.

RESULTS

Lymphatic vessels positive for the lymphatic endothelial cell markers Lyve-1, podoplanin and VEGFR-3 profiles were largely restricted to the connective tissue between the myometrial circular and longitudinal muscle layers; very few lymphatic vessel profiles were observed in the endometrium. VEGF-D immunostaining was present in all uterine compartments (epithelium, stroma, myometrium), although expression was generally low. VEGF-D immunoexpression was slightly but significantly higher in estrus relative to diestrus; and in estradiol-17beta treated mice relative to vehicle or progesterone treated mice. The presence of VEGF-D over-expressing tumor cells did not induce endometrial lymphangiogenesis, although changes were observed in existing vessel profiles. For myometrial lymphatic and endometrial blood vessels, the percentage of profiles containing proliferating endothelial cells, and the cross sectional area of vessel profiles were significantly increased in response to VEGF-D in comparison to control tumor cells. In contrast, no significant changes were noted in myometrial blood vessels. In addition, examples of invading cells or tumor emboli were observed in mice receiving VEGF-D expressing 293EBNA cells.

CONCLUSIONS

These results illustrate that VEGF-D over-expression has differential effects on the uterine vasculature. These effects may facilitate VEGF-D's ability to promote endometrial cancer metastasis and disease progression.

Identification of a gene expression signature for survival prediction in type I endometrial carcinoma

Endometrial cancer is the most common malignancy of the female reproductive tract. In many cases the prognosis is favorable, but 22% of affected women die from the disease. We aimed to study potential differences in gene expression between endometrioid adenocarcinomas from survivors (5-year survival) and nonsurvivors. Forty-five patients were included in the investigation, of which 21 were survivors and 24 were nonsurvivors. The tumors were analyzed with genome-wide expression array analysis, represented by 13,526 genes. Distinct differences in gene expression were found between the groups. A t-test established that 218 genes were significantly differentially expressed (p < 0.001) between the two survival groups, and in a cross-validation test 40 of the 45 (89%) tumors were classified correctly. The 218 differentially expressed genes were subjected to hierachical clustering analysis, which yielded two clusters both exhibiting over 80% homogeneity with respect to survival. When the additional constraint of fold change (FC > 2) was added the hierachical clustering yielded similar results. Stage I tumors are expected to have a favorable prognosis. However, in our tumor material there were six nonsurvivors with stage I tumors. Five out of six stage I nonsurvivors clustered in the nonsurvival fraction. Our findings suggest that a subgroup of early stage endometroid adenocarcinomas can be correctly classified as potentially aggressive by using molecular biology in combination with conventional markers, thereby providing a tool for a more accurate classification and risk evaluation of the individual patient.

High frequency microsatellite instability has a prognostic value in endometrial endometrioid adenocarcinoma, but only in FIGO stage 1 cases

OBJECTIVES

to analyze the prognostic value of microsatellite instability (MSI) in a population-based study of FIGO stage 1-4 endometrial endometrioid adenocarcinomas.

STUDY DESIGN

survival analysis in 273 patients of MSI status and clinico-pathologic features. Using a highly sensitive pentaplex polymerase chain reaction to establish MSI status, cases were divided into microsatellite stable (MSS), MSI-low (MSI-L, 1 marker positive) and MSI-high (MSI-H, 2-5 markers positive).

RESULTS

after 61 months median follow-up (1-209), 34 (12.5%) of the patients developed metastases but only 6.4% of the FIGO 1. MSI (especially as MSI-H vs. MSS/MSI-Lcombined) was prognostic in FIGO 1 but not in FIGO 2-4. The 5 and 10 year recurrence-free survival rates were 98% and 95% in the MSS/MSI-L vs. 85% and 73% in the MSI-H patients (p=0.005).

CONCLUSIONS

MSI-H status assessed by pentaplex polymerase chain reaction is an indicator of poor prognosis in FIGO 1, but not in FIGO 2-4 endometrial endometrioid adenocarcinomas.

Adenocarcinoma corpus uteri stage I-II: results of a treatment programme based upon cytometry

The results of a treatment method on adenocarcinoma corpus uteri stage I-II based upon cytometrically measured DNA ploidy are presented. All patients had a simple hysterectomy. Adjuvant treatment (postoperative vaginal brachytherapy) were given only to those patients with non-diploid tumours regardless of stage and grade. A total of 1,634 women with endometroid adenocarcinoma corpus uteri stage I-II were included where 1,396 patients were followed-up for at least 5 years or until death and the remaining 238 patients were followed-up 3.5-5 years or until death. By using cytometry only, we identified a low-risk group comprising 83% of the patients (with 5.2% dead from their disease) and a high-risk group of 17% (with 15.7% dead from their disease). By using grade only (well- and moderately differentiated vs poorly differentiated), the low-risk group comprised 87% of the patients (with 4.6% dead from their disease) and the high-risk group 13% (with 13% dead from their disease). By using stage only (stage Ia and Ib vs stage Ic and II), the low-risk group comprised 78% of the patients (with 3.6% dead from their disease) and the high risk group 22% (with 14.5% dead from their disease). By combining these prognostic parameters, we were able to identify small subgroups with increased mortality rates in need of adjuvant therapy. As ploidy still had a strong prognostic strength regardless of given adjuvant radiotherapy, we do not believe that this treatment was effective. We therefore recommend future research to be directed toward cytostatics as an alternative adjuvant treatment.

[Mutation and protein expression of PTEN gene in cervical adenocarcinoma and glandular intraepithelial neoplasia]

OBJECTIVE

To investigate PTEN expression and mutation status in the development of cervical adenocarcinoma.

METHODS

Immunohistochemistry study of PTEN protein was performed on 42 cases of cervical adenocarcinoma, 20 cases of cervical glandular intraepithelial neoplasia and 28 cases of normal cervix tissue samples. Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) was used to detect the presence of mutation of exons 5 and 8 of PTEN gene.

RESULTS

Positive expression rates of PTEN protein were 54.8% (23/42), 25.0% (5/20) and 100% (28/28) in cervical adenocarcinoma, cervical glandular intraepithelial neoplasia and normal cervix tissues, respectively. There were significant differences among the 3 groups (P < 0.05). Positive expression rates of PTEN protein were 47.4% (9/19), 20.0% (2/10) and 92.3% (12/13) in mucinous, endometrioid and the other variants of cervical adenocarcinoma, respectively. Mutation rates at exon 5 and exon 8 of PTEN gene were 19.0% (8/42), 45.0% (9/20) and 0 in cervical adenocarcinoma, cervical glandular intraepithelial neoplasia and normal cervix tissue, respectively. There were significant differences among 3 groups (chi(2) = 4.29, chi(2) = 12.70; P < 0.05). The mutation rates were 21.1% (4/19) and 40.0% (4/10) in mucinous and endometrioid variants of cervical adenocarcinoma, respectively. There was no mutation at exons 5 and 8 of PTEN gene detected in other variants of cervical adenocarcinoma.

CONCLUSION

The development of cervical adenocarcionomas is correlated with the mutation and absence of the protein expression of PTEN, likely in the early phase of their carcinogenesis.

The study of phosphate transporter NAPI2B expression in different histological types of epithelial ovarian cancer

The identification of markers that are specifically expressed by different histological types of epithelial ovarian cancer (EOC) may lead to the development of novel and more specific diagnostic and therapeutic strategies. Sodium-dependent phosphate transporter NaPi2b (or MX35 ovarian cancer antigen) is a novel perspective marker of EOC. To date, the studies on NaPi2b/MX35 expression in different histological types of EOC are limited.

AIM

To examine NaPi2b/MX35 expression in different histological types of epithelial ovarian tumors.

METHODS

Here, we describe the analysis of NaPi2b expression in serous (n = 17), endometrioid (n = 8), and mucinous ovarian tumors (n = 3) by Western-blotting (WB), immunohistochemistry and RT-PCR.

RESULTS

The results of immunohistochemical and WB analysis showed that benign and well-differentiated malignant papillary serous tumors as well as well-differentiated malignant endometriod tumors overexpress NaPi2b protein. However, no overexpression of NaPi2b was detected in benign and malignant mucinous tumors as well as in poorly differentiated endometriod tumors. Notably, the expression NaPi2b mRNA was detected in all investigated histological types of EOC.

CONCLUSION

We have shown the differential expression profile of NaPi2b phosphate transporter at protein level in various histological types of epithelial ovarian cancer. This finding might facilitate the development of more effective approaches for diagnosis and treatment of this disease.

[Expression and methylation of adenomatous polyposis coli gene in endometrioid adenocarcinoma]

BACKGROUND & OBJECTIVE

Endometrial carcinoma is a common malignant tumor of female reproductive system, with an increasing incidence in China. Adenomatous polyposis coli (APC) gene, a tumor suppressor gene, is expressed in many tissues, and has a certain relationship with ovarian cancer. This study was to observe the expression and DNA methylation of APC gene in endometrioid adenocarcinoma, and explore its correlations to the occurrence and development of this disease.

METHODS

The methylation, mRNA and protein expression of APC gene were detected by methylation-specific polymerase chain reaction (PCR), reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry in 30 specimens of normal proliferative endometrium, 30 specimens of atypical hyperplastic endometrium and 60 specimens of endometrioid adenocarcinoma.

RESULTS

The methylation rate of APC gene was significantly higher, the positive rates of APC mRNA and protein were significantly lower in endometrioid adenocarcinoma than in atypical hyperplastic endometrium and normal proliferative endometrium (65.0% vs. 33.3% and 23.3%, 33.3% vs. 63.3% and 73.3%, 30.0% vs. 50.0% and 66.7%,P<0.05). There was no significant difference between atypical hyperplastic endometrium and normal endometrium (P>0.05). APC methylation was positively correlated to APC mRNA expression.

CONCLUSION

The expression and DNA methylation of APC gene are certainly related with the occurrence and development of endometrioid adenocarcinoma.

Prolonged survival among women with BRCA germline mutations and advanced endometrial cancer: a case series

It is unclear if BRCA mutation carriers diagnosed with advanced endometrial cancer have a better prognosis compared to sporadic cases. From a population database of BRCA1 and 2 mutation carriers in Southwestern Ontario, Canada, we identified three women with advanced-stage endometrial cancer. They were 57, 59, and 64 years of age, and of English/Scottish, Ashkenazi Jewish, and English heritage, respectively. They had different mutations in BRCA1 (Q1240X:C3837T; 68_69delAG; 1961delA). One had a sarcomatoid carcinoma and two had uterine papillary serous carcinoma. All had stage IVB disease, with surgery followed by adjuvant chemotherapy and/or radiotherapy. Follow-up has ranged from 3.3 to 14.6 years. They are still alive and well with no evidence of recurrent disease. This observation raises the question as to whether BRCA mutations may be associated with a better prognosis in patients with advanced endometrial cancer

N-myc downstream-regulated gene 1 as a downregulated target gene of PTEN in the controlling of tumourigenesis in endometrioid carcinoma

BACKGROUND & OBJECTIVE

Mutation/deletion of PTEN has been known to be involved in the development of many cancers including endometrial carcinoma. NDRG1 (N-myc downstream-regulated gene 1) is reported to be associated with tumourigenesis. PTEN expression has been shown to be correlated with NDRG1 in both prostate and breast cancer. In this study, we explored the possibility that PTEN alteration may cause carcinogenesis of endometrioid carcinoma by regulating the expression of the NDRG1 gene.

METHODS

Tissue blocks of 103 patients with pathologically confirmed endometrioid carcinoma were included. All the carcinoma tissues were accompanied with varied degree of necrosis. Using two-step method and avidin-biotin peroxidase complex immunohistochemistry method, the correlation of the two genes expression in ischaemic area and the relationship of NDRG1 expression between ischaemic and non-ischaemic area in endometrioid carcinomas was evaluated.

RESULTS

PTEN alteration and NDRG1 expressions were significantly increased in the ischaemic area of endometrioid carcinoma compared with their expressions in the normal endometrium respectively (P<0.001, P<0.001). A positive correlation was found between PTEN alteration and NDRG1 expression in the ischaemic area of endometrioid carcinoma.

INTERPRETATION & CONCLUSION

We suggest that NDRG1 may be an important candidate gene in facilitating endometrium carcinogenesis in the adaptation of hypoxia for survival. Alteration of PTEN may upregulate NDRG1 expression, which plays an important role in the process leading to endometrial carcinogenesis.

[Expression of mesothelin mRNA and protein in ovarian carcinomas]

OBJECTIVE

To investigate the expression of mesothelin (MESO) mRNA and protein and its significance in ovarian carcinomas.

METHODS

Semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry were used to detect the expression level of MESO mRNA and protein, respectively, in 124 samples of ovarian tumor and normal tissues, including 84 epithelial ovarian carcinomas, 12 borderline ovarian tumors, 16 benign ovarian tumors and 12 normal ovarian tissues.

RESULTS

The expression of MESO mRNA and protein in epithelial ovarian carcinomas (1.4005 +/- 0.4646, 2.7857 +/- 2.2712) and borderline ovarian tumors (1.0650 +/- 0.3100, 2.9167 +/- 2.391) were significantly higher than that in benign ovarian tumors (0.6463 +/- 0.2419, 1.2500 +/- 1.6125) and normal ovarian tissues (0.6439 +/- 0.2729, 0.9167 +/- 1.2401) (P < 0.05), and also significantly higher in serous cystadenocarcinoma (1.5255 +/- 0.4151, 3.3036 +/- 2.6141) and endometrioid carcinoma (1.5250 +/- 0.5419, 3.0000 +/- 2.3094) than that in mucinous cystadenocarcinoma (1.0675 +/- 0.3149, 1.0556 +/- 1.9242) (P < 0.05). The expression of MESO mRNA and protein in stages II and IV carcinomas (1.5100 +/- 0.4142, 3.6087 +/- 3.3959) was significantly higher than that in stages I and II carcinomas (1.1190 +/- 0.4909, 1.7895 +/- 2.6320; P < 0.05), and also significantly higher in grade 3 carcinomas than that in grade 1 and 2 ones (P < 0.05), but was not correlate with age or serum CA125 of the patients (P > 0.05).

CONCLUSION

The results of this study demonstrated that the expression of MESO mRNA and protein is increased in ovarian carcinomas and borderline ovarian tumors, and MESO may play a role in the adhesion and dissemination of ovarian carcinomas.

Expression of keratinocyte growth factor and its receptor in human endometrial cancer in cooperation with steroid hormones

The keratinocyte factor (KGF) and its receptor (KGFR) are implicated in tissue development and repair. We studied the expression and functions of KGF and KGFR in association with estrogen and progesterone in human endometrial tissues and cells. In non-cancerous human endometrial tissues in the secretory phase, a strong immunoreactivity of KGF in glands, stromal cells, and smooth muscle cells of spiral arteries was detected; however, in proliferative-phase tissues, the immunoreactivity of KGF or KGFR was weak or absent. Most of the 32 endometrioid adenocarcinoma cases showed positive KGF and KGFR stainings (90.6 and 71.9%, respectively). We then studied, using Ishikawa well-differentiated human endometrial cancer cell line that expresses estrogen receptor (ER) and progesterone receptor (PR), the expression of KGF and KGFR in conjunction with estrogen and progesterone, and observed that the KGFR expression of Ishikawa cells was upregulated by estrogen and that this upregulation was markedly enhanced by the coadministration of progesterone. We also observed that KGF administration to cells, with KGFR upregulated expression, stimulated ERK1/2 phosphorylation and cell adhesion to fibronectin. The implications of the hormone-stimulated KGF-KGFR expressions in the regulation of cell behavior associated with human endometrial cancer are discussed.

Novel molecular profiles of endometrial cancer-new light through old windows

Endometrial carcinoma (EC) is the most common gynecological malignancy in the western world. A widely accepted dualistic model, which has been established on a morphological basis, differentiates EC into two broad categories: Type I oestrogen-dependent adenocarcinoma with an endometrioid morphology and Type II non-oestrogen-dependent EC with a serous papillary or clear cell morphology. Molecular genetic evidence indicates that endometrial carcinoma, as described in other malignancies, likely develops as the result of a stepwise accumulation of alterations in cellular regulatory pathways, such as oncogene activation and tumor suppressor gene inactivation, which lead to dysfunctional cell growth. These molecular alterations appear to be specific in Type I and Type II cancers. In type I endometrioid endometrial cancer, PTEN gene silencing in conjunction with defects in DNA mismatch repair genes, as evidenced by the microsatellite instability phenotype, or mutations in the K-ras and/or beta-catenin genes, are recognized major alterations, which define the progression of the normal endometrium to hyperplasia, to endometrial intraepithelial neoplasia, and then on to carcinoma. In contrast, Type II cancers show mutations of TP53 and Her-2/neu and seem to arise from a background of atrophic endometrium. Nevertheless, despite the great effort made to establish a molecularly-based histological classification, the following issues must still be clarified: what triggers the tumor cells to invade the myometrium and what causes vascular or lymphatic dissemination, finally culminating in metastasis? RUNX1, a transcription factor, was recently identified as one of the most highly over-expressed genes in a microarray study of invasive endometrial carcinoma. Another candidate gene, which may be associated with an initial switch to myometrial infiltration, is the transcription factor ETV5/ERM. These studies, as well as those conducted for other genes possibly involved in the mitotic checkpoint as a major mechanism of carcinogenesis in non-endometrioid endometrial cancer, could help in understanding the differences in the biology and the clinical outcome among histological types.

Folate receptor alpha as a tumor target in epithelial ovarian cancer

OBJECTIVES

Folate receptor alpha (FRalpha) is a folate-binding protein overexpressed on ovarian and several other epithelial malignancies that can be used as a target for imaging and therapeutic strategies. The goal of this study is to improve historical data that lack specific information about FRalpha expression in rare histological subtypes, primary disease versus metastatic foci, and recurrent disease.

METHODS

FRalpha expression was analyzed by immunohistochemistry on 186 primary and 27 recurrent ovarian tumors, including 24 pairs of samples obtained from the same individuals at diagnosis and at secondary debulking surgery. For 20 of the 186 primaries, simultaneous metastatic foci were also analyzed. FRalpha staining was analyzed in light of disease morphology, stage, grade, debulking status, and time from diagnosis to recurrence and death.

RESULTS

FRalpha expression was apparent in 134 of 186 (72%) primary and 22 of 27 (81.5%) recurrent ovarian tumors. In 21 of 24 (87.5%) matched specimens, recurrent tumors reflected the FRalpha status detected at diagnosis. Metastatic foci were similar to primary tumors in FRalpha staining. FRalpha status was not associated with time to recurrence or overall survival in either univariate or multivariable analyses.

CONCLUSION

FRalpha expression occurs frequently, especially in the common high-grade, high-stage serous tumors that are most likely to recur. New findings from this study show that FRalpha expression is maintained on metastatic foci and recurrent tumors, suggesting that novel folate-targeted therapies may hold promise for the majority of women with either newly diagnosed or recurrent ovarian cancer.

Promoter hypermethylation contributes to frequent inactivation of a putative conditional tumor suppressor gene connective tissue growth factor in ovarian cancer

Connective tissue growth factor (CTGF) is a secreted protein belonging to the CCN family, members of which are implicated in various biological processes. We identified a homozygous loss of CTGF (6q23.2) in the course of screening a panel of ovarian cancer cell lines for genomic copy number aberrations using in-house array-based comparative genomic hybridization. CTGF mRNA expression was observed in normal ovarian tissue and immortalized ovarian epithelial cells but was reduced in many ovarian cancer cell lines without its homozygous deletion (12 of 23 lines) and restored after treatment with 5-aza 2'-deoxycytidine. The methylation status around the CTGF CpG island correlated inversely with the expression, and a putative target region for methylation showed promoter activity. CTGF methylation was frequently observed in primary ovarian cancer tissues (39 of 66, 59%) and inversely correlated with CTGF mRNA expression. In an immunohistochemical analysis of primary ovarian cancers, CTGF protein expression was frequently reduced (84 of 103 cases, 82%). Ovarian cancer tended to lack CTGF expression more frequently in the earlier stages (stages I and II) than the advanced stages (stages III and IV). CTGF protein was also differentially expressed among histologic subtypes. Exogenous restoration of CTGF expression or treatment with recombinant CTGF inhibited the growth of ovarian cancer cells lacking its expression, whereas knockdown of endogenous CTGF accelerated growth of ovarian cancer cells with expression of this gene. These results suggest that epigenetic silencing by hypermethylation of the CTGF promoter leads to a loss of CTGF function, which may be a factor in the carcinogenesis of ovarian cancer in a stage-dependent and/or histologic subtype-dependent manner.

Coexpression index of estrogen receptor alpha mRNA isoforms in simple, complex hyperplasia without atypia, complex atypical hyperplasia and adenocarcinoma

OBJECTIVE

Estrogen receptor isoforms are postulated to play an important role in modulating the estrogen response. To clarify the molecular mechanisms through which malignant changes are activated in endometrium, this study aims to examine the expression profiles of wild-type ER-alpha and their splice variants and to assess the number of coexisting mRNA isoforms of ER-alpha in normal endometrium as well as in endometrial hyperplasia and endometrial endometrioid adenocarcinoma.

METHODS

Human endometrium and specimens including endometrial hyperplasia and endometrial cancer were obtained during surgery. Endometrial data were classified into four groups: simple hyperplasia (n=24), complex hyperplasia (n=15), atypical hyperplasia (n=11), endometrial endometrioid adenocarcinoma (n=19) (grade 1, grade 2 morphological degree) and proliferative endometrium (n=24) as a control group. Total cellular RNA was extracted from endometrial tissues using Total RNA Prep Plus. A real-time quantitative RT-PCR assay was developed to quantify the wild-type ER-alpha and ER-alpha mRNA isoforms copy numbers. We have evaluated the variation in ERs mRNA level between normal endometrium and endometrial hyperplasia and adenocarcinoma. We also evaluated the "sharing indicator". It is a factor of mRNA ER-alpha holding shares in whole mRNA it assume quotient of ER-alpha slicing variant to all variants of mRNA ER-alpha.

RESULTS

It was found that the number of coexisting mRNA isoforms was significantly higher in adenocarcinoma endometrium than that evaluated for various degrees of hyperplasia endometrium and normal proliferative endometrium (p<0.05, the Kruskal-Wallis test).

CONCLUSION

The risk for progression of endometrial hyperplasia to atypical hyperplasia and eventually endometrioid adenocarcinoma may be accompanied by an increase in the number of alternative splicing variants of mRNA ER-alpha.

The Role of p53 Mutation in the Carcinomas Arising from Endometriosis

To probe the mechanism of the development of ovarian cancer from endometriosis, which is a multistep process that involves the activation of oncogenes and inactivation of tumor suppressor genes, we evaluated p53 mutations in solitary endometriosis and endometriosis coexisting with ovarian clear cell carcinoma (OCCA) and ovarian endometrioid carcinoma (OEC). We examined 7 cases of solitary ovarian endometriosis, 13 cases of OCCA, and 9 cases of OEC. Cancer tissue specimens that also contained endometriosis without atypia were chosen. Using a laser microdissection system, epithelial cells from the areas of endometriosis were isolated, and DNA was extracted. We amplified exons 5, 6, 7, and 8 of the p53 gene, and direct sequencing was performed. p53 mutation was observed in 4 (30.8%) of 13 specimens of endometriosis coexisting with OCCA, whereas no mutations were detected in solitary endometriosis or endometriosis coexisting with OEC. We thought that some genetic alterations, which induce p53 mutations in endometriosis, may affect malignant transformation of endometriosis into OCCA.

Estrogen receptor ?1 and the ?2/?cx isoforms in nonneoplastic endometrium and in endometrioid carcinoma

Estrogen receptor beta (ERbeta) has five carboxyl-terminal (C-terminal) isoforms derived from alternative splicing. ERbeta1 is the wild-type receptor whereas ERbeta2/betacx lacks the activation function (AF)-2 core essential for ligand-dependent transcriptional activation and so behaves as a dominant-negative receptor affecting the function of ERalpha. The objective of this study was to analyze the expression of ERbeta1 and ERbeta2/betacx isoforms in nonneoplastic endometrium and endometrioid carcinoma. The study was conducted on samples of 22 proliferative endometrium, 15 secretory endometrium, 20 simple hyperplasia (without atypia), and 26 endometrioid carcinomas. The transcript and protein levels were determined by semiquantitative reverse transcriptase-polymerase chain reaction and immunohistochemistry, respectively. For the detection of ERbeta2/betacx protein, a polyclonal antibody was raised to its unique C-terminus, characterized, and used in immunohistochemistry. The two ERbeta isoforms are expressed in the proliferative and secretory phase endometrium with no significant change in their relative levels. The levels of the ERbeta1 isoform were lower as compared to the levels of ERbeta2 in all the groups studied. Expression of ERbeta2/betacx was decreased in endometrioid carcinoma as compared to proliferative endometrium (P < 0.01). A significant decrease of the ERbeta2/ERbetacx transcript was observed with higher grade tumors (P = 0.041). Progesterone receptor (PR) expression was not influenced by either of the ERbeta isoforms which was observed by logistic regression analysis in all the groups. The coexpression of ERbeta2/betacx with ERalpha did not affect PR levels (logistic regression analysis). Thus, we conclude in the human endometrium, there is significant ERbeta2/betacx isoform expression and alterations in its levels could be involved in endometrial cancer progression.

Mechanism and functional consequences of loss of FOXO1 expression in endometrioid endometrial cancer cells

The forkhead transcription factor FOXO1, a downstream target of phosphatidylinositol-3-kinase/Akt signalling pathway, regulates cyclic differentiation and apoptosis in normal endometrium, but its role in endometrial carcinogenesis is unknown. Screening of endometrial cancer cell lines demonstrated that FOXO1 is expressed in HEC-1B cells, but not in Ishikawa cells, which in turn highly express the FOXO1 targeting E3-ubiquitin ligase Skp2. FOXO1 transcript levels were also lower in Ishikawa cells and treatment with the proteasomal inhibitor was insufficient to restore expression. Lack of FOXO1 expression in Ishikawa cells was not accounted for by differential promoter methylation or activity, but correlated with increased messenger RNA (mRNA) turnover. Comparative analysis demonstrated that HEC-1B cells proliferate slower, but are more resistant to paclitaxel-mediated cell death than Ishikawa cells, which were partially reversed upon silencing of FOXO1 in HEC-1B cells or its re-expression in Ishikawa cells. We further show that FOXO1 is required for the expression of the growth arrest- and DNA-damage-inducible gene GADD45alpha. Analysis of biopsy samples demonstrated a marked loss of FOXO1 and GADD45alpha mRNA and protein expression in endometrioid endometrial cancer compared to normal endometrium. Together, these observations suggest that loss of FOXO1 perturbs endometrial homeostasis, promotes uncontrolled cell proliferation and increases susceptibility to genotoxic insults.

Soluble isoforms but not the transmembrane form of coxsackie-adenovirus receptor are of clinical relevance in epithelial ovarian cancer

The coxsackie-adenovirus receptor (hCAR) has been extensively studied in context of adenoviral-based gene therapy for cancer. However, there is strong evidence that besides its decisive role in coxsackie and adenovirus cell-entry, hCAR is a component of epithelial tight junctions and involved in cell-cell adhesions in normal and cancer cells. Furthermore, this adhesion molecule behaves like a cell surface receptor endowed with tumor suppressive properties via signal transduction. Moreover, 3 truncated soluble isoforms of hCAR were recently identified. We investigated the quantitative expression of all known CAR isoforms in a training set of 140 ovarian cancer samples and 21 controls by RT-PCR. The expression levels of the various isoforms were compared with clinicopathologic parameters and their prognostic significance was assessed. Expression levels of all CAR isoforms were elevated in ovarian carcinomas as compared with those of non-malignant controls. mRNA-expression correlated with protein levels. Moreover, expression of the soluble isoforms CAR 3/7 and CAR 4/7 but not that of hCAR was significantly increased in advanced ovarian cancer as revealed by a highly significant correlation with FIGO stage and residual disease > 2 cm in diameter after debulking surgery. High expression of CAR 3/7 and 4/7 was shown to be of independent prognostic relevance for progression-free (CAR 4/7) and overall survival (CAR 3/7 and CAR 4/7). In conclusion, soluble CAR isoforms 3/7 and 4/7 may play a pivotal role in ovarian cancer biology, possibly by counteracting migration- and growth-inhibitory properties of the membranous hCAR and thus favoring cancer cell dissemination throughout the peritoneal cavity.