cDNA microarray analysis and immunohistochemistry reveal a distinct molecular phenotype in serous endometrial cancer compared to endometrioid endometrial cancer

Intra-tumor heterogeneity for endometrial cancer and its clinical significance

BACKGROUND

Management of tumors has become more complex owing to tumor heterogeneity. Fewer studies have been performed on intra-tumor heterogeneity of endometrial cancer (EC) until now. Therefore, it is of great clinical value to explore the intra-tumor heterogeneity of EC based on clinical features and gene expression profiles.

METHODS

A total of 1688 patients with EC were screened and 114 patients were finally selected, including specimens from 84 patients with primary EC without relapse (PE) and the paired metastases (P-M) specimens, as well as specimens from 30 patients with primary EC with relapse (RPE) and the paired relapsed EC (P-RE) specimens. Microarray and RNA-seq were used to detect gene expression of EC samples. Clinicopathological characteristics and molecular data were compared between PE and P-M groups and between RPE and P-RE groups to explore the intra-tumor heterogeneity of EC.

RESULTS

The clinical intra-tumor spatial heterogeneity of pathological type, grade, ER status, and PR status between PE and P-M were 17.9%, 13.1%, 28.6%, and 28.6%, respectively. The clinical intra-tumor spatiotemporal heterogeneity of pathological type, grade, ER status, and PR status between RPE and P-RE were 16.7%, 33.3%, 25.0%, and 37.5%, respectively. Cluster analysis sorts EC samples based on progression type of lesion and their pathological type. There were differentially expressed genes between PE and P-M and between RPE and P-RE, of which gene ontology and Kyoto Encyclopedia of Genes and Genomes analysis were mainly enriched in cell proliferation, the p53 signaling pathway, etc. CONCLUSIONS:: Clinical and molecular data showed that there was spatiotemporal heterogeneity in intra-tumor of EC, which may add to the complexity of diagnosis and therapeutics for EC. Considering the intra-tumor heterogeneity, sequential chemotherapy and precision medicine may be a more suitable treatment plan for EC.

Identification of Potential Crucial Genes Associated With the Pathogenesis and Prognosis of Endometrial Cancer

Background and Objective

Endometrial cancer (EC) is a common gynecological malignancy worldwide. Despite advances in the development of strategies for treating EC, prognosis of the disease remains unsatisfactory, especially for advanced EC. The aim of this study was to identify novel genes that can be used as potential biomarkers for identifying the prognosis of EC and to construct a novel risk stratification using these genes.

Methods and Results

An mRNA sequencing dataset, corresponding survival data and expression profiling of an array of EC patients were obtained from The Cancer Genome Atlas and Gene Expression Omnibus, respectively. Common differentially expressed genes (DEGs) were identified based on sequencing and expression as given in the profiling dataset. Pathway enrichment analysis of the DEGs was performed using the Database for Annotation, Visualization, and Integrated Discovery. The protein-protein interaction network was established using the string online database in order to identify hub genes. Univariate and multivariable Cox regression analyses were used to screen prognostic DEGs and to construct a prognostic signature. Survival analysis based on the prognostic signature was performed on TCGA EC dataset. A total of 255 common DEGs were found and 11 hub genes (TOP2A, CDK1, CCNB1, CCNB2, AURKA, PCNA, CCNA2, BIRC5, NDC80, CDC20, and BUB1BA) that may be closely related to the pathogenesis of EC were identified. A panel of 7 DEG signatures consisting of PHLDA2, GGH, ESPL1, FAM184A, KIAA1644, ESPL1, and TRPM4 were constructed. The signature performed well for prognosis prediction (p < 0.001) and time-dependent receiver-operating characteristic (ROC) analysis displayed an area under the curve (AUC) of 0.797, 0.734, 0.729, and 0.647 for 1, 3, 5, and 10-year overall survival (OS) prediction, respectively.

Conclusion

This study identified potential genes that may be involved in the pathophysiology of EC and constructed a novel gene expression signature for EC risk stratification and prognosis prediction.

Bioinformatics analysis of key differentially expressed genes in well and poorly differentiated endometrial carcinoma

Endometrial carcinoma (EC) is one of the most common gynecological malignancies. The malignant degree increases between grade (G)1 and G3, and EC of G3 usually presents a high recurrence rate and poor prognosis. Therefore, the present study aimed to examine the principal genes associated with the degree of differentiation in EC. The microarrays GSE17025, GSE24537 and GSE35784, representing data of Type I EC samples of G1 and G3, were downloaded from the Gene Expression Omnibus. The differentially expressed genes (DEGs) and differentially expressed micro (mi)RNAs (DEMs) were identified, followed by functional enrichment analyses and interaction network construction. In total, 83 upregulated and 130 downregulated DEGs with the same expression trends in two mRNA datasets were screened. The upregulated DEGs were primarily enriched in 'mitotic cell cycle process', 'cell cycle process' and 'mitotic cell cycle'; while the downregulated DEGs were enriched in 'cellular component assembly involved in morphogenesis', 'cell projection organization' and 'microtubule‑based movement'. From the protein‑protein interaction network, DNA topoisomerase IIα, kinesin family member 11, cyclin B1 and BUB1 mitotic checkpoint serine/threonine were identified as foremost hub genes. One module was extracted and involved in 'mitotic cell cycle process' and 'cell cycle process'. Based on the analysis of DEMs and the miRNA‑target regulatory network, miRNA‑9 may be the most important upregulated DEM, and the DEGs forkhead box P1 and cyclin E1 may serve vital roles in the differentiation of EC. In conclusion, principal genes were identified that may be determinants of the carcinogenesis of poorly differentiated EC, which may facilitate the examination of potential molecular mechanisms. These genes may additionally help identify candidate biomarkers and novel therapeutic targets for poorly differentiated EC.

Dual-specificity Phosphatase 1 Deficiency Induces Endometrioid Adenocarcinoma Progression via Activation of Mitogen-activated Protein Kinase/Extracellular Signal-regulated Kinase Pathway

Background:

Previously, we reported that dual-specificity phosphatase 1 (DUSP1) was differentially expressed in endometrioid adenocarcinoma (EEA). However, the role of DUSP1 in EEA progression and the relationship between DUSP1 and medroxyprogesterone (MPA) are still unclear.

Methods:

The expression of DUSP1 in EEA specimens was detected by immunohistochemical analysis. The effect of DUSP1 on cell proliferation was analyzed by Cell Counting Kit 8 and colony formation assay, and cell migration was analyzed by transwell assay. MPA-induced DUSP1 expression in EEA cells was measured by Western blot.

Results:

DUSP1 expression was deficient in advanced International Federation of Gynecology and Obstetrics stage, high-grade and myometrial invasive EEA. In EEA cell lines (Hec1A, Hec1B, RL952, and Ishikawa), the DUSP1 expression was substantially higher in Ishikawa cells than in other cell lines (P < 0.05). Knockdown of DUSP1 promoted Ishikawa cells proliferation, migration, and activation of mitogen-activated protein kinases/extracellular signal-regulated kinase (MAPK/Erk) pathway. MPA-induced DUSP1 expression and inhibited MAPK/Erk pathway in Ishikawa cells.

Conclusions:

Our data suggest that DUSP1 deficiency promotes EEA progression via MAPK/Erk pathway, which may be reversed by MPA, suggesting that DUSP1 may serve as a potential therapeutic target for the treatment of EEA.

DNA ploidy may be a prognostic marker in stage I and II serous adenocarcinoma of the endometrium

In patients with serous adenocarcinoma (SAC) of the endometrium, we evaluated the prognostic importance of clinicopathological parameters, DNA ploidy, and immunoexpression of p53, estrogen receptor (ER), progesterone receptor (PR), and Ki-67. In a series of 73 stage I and II SAC, DNA ploidy analysis was performed on hysterectomy specimens using DNA image cytometry. Immunohistochemical analysis of p53, ER, PR, and Ki-67 expression was additionally performed. In the review of the histological slides by three gynecologic pathologists, the presence of a serous component was not agreed upon in 17 (23 %) cases. The remaining 56 cases, consisting of pure SAC or SAC mixed with endometrioid adenocarcinoma, were further analyzed. Tumor recurrence was observed in 14 patients, and 28 patients died during the follow-up period. Patients with diploid (n = 19), aneuploid (n = 29), and tetraploid (n = 8) tumor had 5-year recurrence rates of 10, 38, and 53 %, respectively (p = 0.09). A DNA ploidy parameter, 5c exceeding rate, was found to be a prognostic marker for recurrence (p = 0.03), progression-free survival (p < 0.01), and overall survival (p = 0.02). Immunoexpression of p53, ER, PR, and Ki-67 did not have prognostic value, and the same was true for FIGO stage, lymphovascular invasion, the extent of myometrial invasion, and lymphadenectomy. The histological diagnosis of SAC may be difficult in some cases. Established clinicopathological parameters do not seem to be strong prognosticators in stage I and II disease. A DNA ploidy parameter, 5c exceeding rate, may be a prognostic marker in this patient group and should be further validated in larger series.

GRP78 induced by estrogen plays a role in the chemosensitivity of endometrial cancer

OBJECTIVE

Molecular chaperone 78 kDa glucose-regulated protein (GRP78) is a residential protein in the endoplasmic reticulum (ER) that is induced by an unfolded-protein response triggered under many kinds of stress against a cell. GRP78 is also known to act as an anti-apoptotic factor by protecting ER-stress-induced cell death. In this study, we examined the significance of GRP78 expression in endometrial cancer.

METHODS

Tissue samples obtained from patients with a diagnosis of enodometrial cancer were subjected to immunohistochemistry and RT-PCR to determine protein and mRNA expression levels of GRP78 and estrogen receptor α. We used Western blot and RT-PCR to examine whether estrogen induced GRP78 expression in cancer cell lines. Western blots and MTT assays of GRP78 siRNA transfected Ishikawa and HHUA cells were used to demonstrate whether GRP78 is involved in chemoresistence.

RESULTS

GRP78 was highly expressed in well and moderately differentiated endometrial carcinoma. Estrogen induced GRP78 expression, which was correlated with cell viability and resistance to paclitaxel and cisplatin. Western blot analysis indicated that active caspase-3 and the 85-kDa protein poly (ADP-ribose) polymerase (PARP) were increased by incubation with either paclitaxel or cisplatin, suggesting that the apoptotic pathway was involved in cancer-drug-induced cell death.

CONCLUSIONS

These results may open up a novel therapeutic strategy for endometrial cancer: namely, the targeting of GRP78 to sensitize the tumor cell to chemotherapy.

Endometrial carcinoma: molecular alterations involved in tumor development and progression

In the western world, endometrial carcinoma (EC) is the most common cancer of the female genital tract. The annual incidence has been estimated at 10-20 per 100,000 women. Two clinicopathological variants are recognized: the estrogen related (type I, endometrioid) and the non-estrogen related (type II, non-endometrioid).The clinicopathological differences are paralleled by specific genetic alterations, with type I showing microsatellite instability and mutations in phosphatase and tensin homologue deleted on chromosome 10, PIK3CA, K-RAS and CTNNB1 (β-catenin), and type II exhibiting TP53 mutations and chromosomal instability. Some non-endometrioid carcinomas probably arise from pre-existing endometrioid carcinomas as a result of tumor progression and, not surprisingly, some tumors exhibit combined or mixed features at the clinical, pathological and molecular levels. In EC, apoptosis resistance may have a role in tumor progression. Understanding pathogenesis at the molecular level is essential in identifying biomarkers for successful targeted therapies. In this review, the genetic changes of endometrial carcinogenesis are discussed in the light of the morphological features of the tumors and their precursors.