Genomic Sub-Classification of Ovarian Clear Cell Carcinoma Revealed by Distinct Mutational Signatures

Ovarian clear cell carcinoma (OCCC) is characterized by dismal prognosis, partially due to its low sensitivity to standard chemotherapy regimen. It is also well-known for presenting unique molecular features in comparison to other epithelial ovarian cancer subtypes. Here, we aim to identify potential subgroups of patients in order to (1) determine their molecular features and (2) characterize their mutational signature. Furthermore, we sought to perform the investigation based on a potentially clinically relevant setting. To that end, we assessed the mutational profile and genomic instability of 55 patients extracted from the Gynecologic Cancer Database (DGCD) by using a panel comprised of 409 cancer-associated genes and a microsatellite assay, respectively; both are currently used in our routine environment. In accordance with previous findings, ARID1A and PIK3CA were the most prevalent mutations, present in 49.1% and 41.8%, respectively. From those, the co-occurrence of ARID1A and PIK3CA mutations was observed in 36.1% of subjects, indicating that this association might be a common feature of OCCC. The microsatellite instability frequency was low across samples. An unbiased assessment of signatures identified the presence of three subgroups, where “PIK3CA” and “Double hit” (with ARID1A and PIK3CA double mutation) subgroups exhibited unique signatures, whilst “ARID1A” and “Undetermined” (no mutations on ARID1A nor PIK3CA) subgroups showed similar profiles. Those differences were further indicated by COSMIC signatures. Taken together, the current findings suggest that OCCC presents distinct mutational landscapes within its group, which may indicate different therapeutic approaches according to its subgroup. Although encouraging, it is noteworthy that the current results are limited by sample size, and further investigation on a larger group would be crucial to better elucidate them.

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miR-29b regulates cell proliferation and invasion in human ovarian clear cell carcinoma by targeting Lysyl oxidase (LOX)

Archives of Biological Sciences ◽

10.2298/abs150420020w ◽

2016 ◽

Vol 68 (1) ◽

pp. 155-163

Author(s):

Xuan Wang ◽

Yan Wang ◽

Guichan Wang ◽

Peishu Liu

Keyword(s):

Ovarian Cancer ◽

Cell Carcinoma ◽

Clear Cell ◽

Clear Cell Carcinoma ◽

Lysyl Oxidase ◽

Gynecologic Cancer ◽

Tumor Formation ◽

Migration And Invasion ◽

Ovarian Clear Cell Carcinoma ◽

Proliferation And Invasion

Ovarian cancer is the leading cause of death from gynecologic cancer, reflecting its chemoresistance and frequent late diagnosis, and suggesting that a more effective treatment approach is needed. Lysyl oxidase (LOX) is involved in important biological processes such as gene regulation, cell signaling and cell motility, its deregulation contributing to tumor formation and development. Although it is known that LOX is involved in proliferation, migration and invasion in several types of tumors, studies of LOX in ovarian cancers are scarce. To explore the molecular regulation mechanisms in ovarian cancer tumorigenesis, the expression change and the function of LOX was confirmed in ovarian tissues and cells, which suggested that LOX is a tumor suppressor gene. To further understand how LOX expression is regulated in ovarian cancer, microRNAs(miRNAs) were considered because of their role in post-transcriptional regulation of many genes. Recent work has described differential expression of mature miRNAs in human cancers. Bioinformatics prediction which was used to find the appropriate miRNA regulating LOX, revealed that miR-29b regulates LOX protein level via its binding site on the 3'UTR of LOX mRNAin ES-2 cells, a human ovarian clear cell carcinoma cell line. miR-29b knockdown inhibited proliferation and invasion in ES-2 cells. Taken together, these findings suggest that influencing LOX regulation bychanging the level of miR-29b expression could provide a novel potential approachfor treating human ovarian clear cell carcinoma.

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Expression of the chrXq27.3 miRNA cluster in recurrent ovarian clear cell carcinoma and its impact on cisplatin resistance

Oncogene ◽

10.1038/s41388-020-01595-3 ◽

2021 ◽

Author(s):

Kosuke Yoshida ◽

Akira Yokoi ◽

Mai Sugiyama ◽

Shingo Oda ◽

Kazuhisa Kitami ◽

...

Keyword(s):

Cell Carcinoma ◽

Cisplatin Resistance ◽

Clear Cell ◽

Clear Cell Carcinoma ◽

Critical Role ◽

Molecular Characteristics ◽

Mirna Cluster ◽

Ovarian Clear Cell Carcinoma ◽

Dismal Prognosis ◽

Cancer Tissues

AbstractOvarian clear cell carcinoma (OCCC) is a histological subtype of epithelial ovarian cancer and exhibits dismal prognosis due to chemoresistance. Moreover, only few effective therapeutic options exist for patients with recurrent OCCC, and an understanding of its molecular characteristics is essential for the development of novel therapeutic approaches. In the present study, we investigated unique MicroRNAs (miRNA) profiles in recurrent/metastatic OCCC and the role of miRNAs in cisplatin resistance. Comprehensive miRNA sequencing revealed that expression of several miRNAs, including miR-508-3p, miR-509-3p, miR-509-3-5p, and miR-514a-3p was remarkably less in recurrent cancer tissues when compared with that in paired primary cancer tissues. These miRNAs are located in the chrXq27.3 region on the genome. Moreover, its expression was negative in omental metastases in two patients with advanced OCCC. In vitro analyses revealed that overexpression of miR-509-3p and miR-509-3-5p reversed cisplatin resistance and yes-associated protein 1 (YAP1) was partially responsible for the resistance. Immunohistochemistry revealed that YAP1 expression was inversely correlated with the chrXq27.3 miRNA cluster expression. In conclusion, these findings suggest that alteration of the chrXq27.3 miRNA cluster could play a critical role in chemoresistance and miRNAs in the cluster and their target genes can be potential therapeutic targets.

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