RESUMO
Gene structure alterations, such as chromosomal rearrangements that develop fusion genes, often contribute to tumorigenesis. It has been shown that the fusion genes identified in public RNA-sequencing datasets are mainly derived from intrachromosomal rearrangements. In this study, we explored fusion transcripts in clinical ovarian cancer specimens based on our RNA-sequencing data. We successfully identified an in-frame fusion transcript SPON1-TRIM29 in chromosome 11 from a recurrent tumor specimen of high-grade serous carcinoma (HGSC), which was not detected in the corresponding primary carcinoma, and validated the expression of the identical fusion transcript in another tumor from a distinct HGSC patient. Ovarian cancer A2780 cells stably expressing SPON1-TRIM29 exhibited an increase in cell growth, whereas a decrease in apoptosis was observed, even in the presence of anticancer drugs. The siRNA-mediated silencing of SPON1-TRIM29 fusion transcript substantially impaired the enhanced growth of A2780 cells expressing the chimeric gene treated with anticancer drugs. Moreover, a subcutaneous xenograft model using athymic mice indicated that SPON1-TRIM29-expressing A2780 cells rapidly generated tumors in vivo compared to control cells, whose growth was significantly repressed by the fusion-specific siRNA administration. Overall, the SPON1-TRIM29 fusion gene could be involved in carcinogenesis and chemotherapy resistance in ovarian cancer, and offers potential use as a diagnostic and therapeutic target for the disease with the fusion transcript.
Assuntos
Resistencia a Medicamentos Antineoplásicos/genética , Proteínas de Fusão Oncogênica , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Animais , Apoptose/genética , Sequência de Bases , Linhagem Celular Tumoral , Proliferação de Células/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Ovarianas/tratamento farmacológico , RNA Mensageiro/genética , RNA Mensageiro/metabolismoRESUMO
Estrogen-responsive endometrial cancer (EC) is prevalent in uterine cancer. Its precise molecular mechanisms remain to be elucidated partly because of limited availability of estrogen-sensitive EC models recapitulating clinical pathophysiology. We previously established EC patient-derived cancer cell (EC-PDC) spheroid culture with high expression of estrogen receptor α (ERα). Using this EC-PDC, we study the transcriptional regulation and function of estrogen-responsive finger protein (Efp), a prototypic tripartite motif (TRIM) protein that modulates protein degradation and RNA processing. Intense estrogen-dependent EFP mRNA induction and high ERα occupancy to EFP estrogen responsive element (ERE) were observed in EC-PDC. Luciferase reporter gene assay showed that the ERE facilitates EFP transcriptional activity estrogen-dependently. siRNA-mediated Efp silencing in EC-PDC resulted in suppressed spheroid proliferation and altered gene expression profile, featuring downregulation of genes related to cell cycle (e.g., CDK6) and inflammation/immune responses (e.g., IL10RA, IL26, and IL6ST) while unaffected expression of cancer stemness-related markers. Taken together, EC-PDC spheroid culture is a powerful EC tool that enables to dissect Efp-mediated ERα signaling pathways as an estrogen-sensitive EC model. This study provides an insight into alternative EC therapeutic strategies targeting ERα-Efp axis.
Assuntos
Neoplasias do Endométrio/genética , Neoplasias do Endométrio/patologia , Estrogênios/farmacologia , Perfilação da Expressão Gênica , Esferoides Celulares/patologia , Fatores de Transcrição/metabolismo , Proteínas com Motivo Tripartido/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Sequência de Bases , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Neoplasias do Endométrio/imunologia , Receptor alfa de Estrogênio/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Fatores de Transcrição/genética , Transcrição Gênica/efeitos dos fármacos , Proteínas com Motivo Tripartido/genética , Ubiquitina-Proteína Ligases/genéticaRESUMO
Endometrial cancer (EC) is a common gynecological malignancy with relatively favourable prognosis, although alternative diagnostic and therapeutic options remain to be explored for advanced disease. Recent studies enabled to apply microRNAs (miRs) to clinical cancer management as promising diagnostic and therapeutic biomarkers. We here aimed to identify proliferation-associated miRNAs and characterize their functions in EC cells. Our small RNA-sequencing analysis showed that miR-191 is abundantly expressed in HEC-1A and Ishikawa EC cells along with the high expression of miR-182, which was previously characterized as an EC proliferation-related miRNA in EC. We showed that miR-191 was upregulated in EC tissues than in adjacent normal tissues and its knockdown repressed EC cell proliferation. In silico miRNA target screening identified that ten-eleven translocation 1 (TET1) is one of the putative miR-191 targets. TET1 expression could be downregulated by miR-191 through the mRNA-miRNA interaction in the 3'-untranslated region of TET1. In line with TET1 functions as a methylcytosine dioxygenase, which removes genome-wide DNA methylation marks, decreased TET1 expression resulted in hypermethylation in the promotor region of tumour suppressor adenomatous polyposis coli. Taken together, miR-191 could function as an oncogenic miRNA in EC and serve as a prospective diagnostic and therapeutic target for advanced disease.