Increasing numbers of studies have confirmed that long noncoding RNA (lnc RNA ) play a critical role in epithelial ovarian cancer ( EOC ) progression. However, the potential function of the lnc RNA tumor protein translationally controlled 1 ( TPT 1) antisense RNA 1 ( TPT 1‐ AS 1) in EOC is unclear. In this study, we aimed to uncover the biological roles and regulatory mechanisms of TPT 1‐ AS 1 in EOC progression and metastasis. First, TPT 1‐ AS 1 expression was significantly higher in EOC metastatic tissue and cell lines than in their respective control counterparts. In addition, ectopic TPT 1‐ AS 1 expression was strongly associated with unfavorable EOC clinicopathological features, including FIGO stage, tumor size and tumor differentiation. TPT 1‐ AS 1 overexpression remarkably induced cell proliferation, migration and invasion, and significantly attenuated cell adhesion ability in vitro and facilitated nude mouse subcutaneous xenograft growth and intraperitoneal metastasis in vivo, while the downregulation of TPT 1‐ AS 1 expression produced the opposite effect in vitro. Mechanistically, TPT 1‐ AS 1 was proven to be primarily distributed in EOC cell nuclei and positively modulated TPT 1 promoter activity and transcription. Moreover, the oncogenic effects of TPT 1‐ AS 1 could be reversed by TPT 1 depletion, and the PI 3K/ AKT signaling pathway downstream of TPT 1 was also altered. These results suggested that TPT 1‐ AS 1 induced EOC tumor growth and metastasis through TPT 1 and downstream PI 3K/ AKT signaling and that TPT 1‐ AS 1 may be a promising therapeutic target for EOC .

Epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy, with typically extensive intraperitoneal implantation leading to poor prognosis. Our previous study preliminarily demonstrated β-hCG can promote tumorigenesis in immortalized nontumorigenic ovarian epithelial cells. In this study, the roles and mechanisms of β-hCG in regulating EOC proliferation and metastasis were thoroughly explored. First, histologically, β-hCG was aberrantly overexpressed in human EOC metastatic tissues, and significantly correlated with FIGO stage, tumor size, differentiation, histologic grade and high grade serous ovarian carcinoma (HGSOC) (P < 0.05). However, serologically, β-hCG expression showed no significant difference between EOC and nonmalignant ovarian patients. Second, β-hCG was confirmed to have no significant effects on EOC proliferation in vitro and in vivo, while β-hCG upregulation was proven to promote migration and invasion ability in ES-2 and OVCAR-3 cells in vitro (P < 0.05), and β-hCG downregulation in SKOV3 cells had the opposite effect. Moreover, more invadopodia protrusions, mitochondria accumulations and cytoskeletal rearrangements were observed in β-hCG-overexpressing ES-2 cells, while β-hCG-depleted SKOV3 cells produced the opposite effect. Furthermore, β-hCG was confirmed to clearly facilitate intraperitoneal metastasis in nude mouse orthotopic ovarian xenograft models. Importantly, these effects of β-hCG were mediated by activation of the ERK/MMP2 signaling pathway, independently of luteinizing hormone/chorionic gonadotropin receptor (LHCGR) presence, and inhibition the pathway with the p-ERK1/2 inhibitor SCH772984 significantly impaired the tumor-promoting effects induced by β-hCG. Collectively, these data provide new insight into the roles and mechanisms of β-hCG in regulating EOC metastasis through ERK/MMP2 signaling pathway and may become a new target for therapeutic intervention.

Myeloid‐derived suppressor cells (MDSCs) are known to contribute to tumour immune evasion, and studies have verified that MDSCs can induce cancer stem cells (CSCs) and promote tumour immune evasion in breast cancers, cervical cancers and glioblastoma. However, the potential function of MDSCs in regulating CSCs in epithelial ovarian cancer (EOC) progression is unknown. Our results indicated that compared to nonmalignant ovarian patients, EOC patients showed a significantly increased proportion of MDSCs in the peripheral blood. In addition, MDSCs dramatically promoted tumour sphere formation, cell colony formation and CSC accumulation, and MDSCs enhanced the expression of the stemness biomarkers NANOG and c‐MYC in EOC cells during coculture. Moreover, the mechanisms by which MDSCs enhance EOC stemness were further explored, and 586 differentially expressed genes were found in EOC cells cocultured with or without MDSCs; during coculture, the expression level of colony‐stimulating factor 2 (CSF2) was significantly increased in EOC cells cocultured with MDSCs. Furthermore, the depletion of CSF2 in EOC cells was successfully performed, the promotive effects of MDSCs on EOC cell stemness could be markedly reversed by downregulating CSF2 expression, p‐STAT3 signalling pathway molecules were also altered, and the p‐STAT3 inhibitor could markedly reverse the promotive effects of MDSCs on EOC cell stemness. In addition, the CSF2 expression level was correlated with EOC clinical staging. Therefore, MDSCs enhance the stemness of EOC cells by inducing the CSF2/p‐STAT3 signalling pathway. Targeting MDSCs or CSF2 may be a reasonable strategy for enhancing the efficacy of conventional treatments. Database Gene expression data files are available in the GEO databases under the accession number(s) GSE145374 .

Human chorionic gonadotropin β (β-hCG) is a well-known and accurate marker for the diagnosis and monitoring of pregnancy, trophoblastic tumors and ovarian germ cell tumors. Recently, β-hCG has been found to be closely related to poor prognosis and metastasis in various other malignant tumors, while its role and mechanism in ovarian cancer is still unclear. In the present study, lentiviral-mediated transfection and small interfering RNA (siRNA) were used to alter β-hCG expression in the ovarian cancer cell lines ES-2 and SKOV3, respectively. Then, migration and invasion activity regulated by β-hCG were evaluated by wound-healing and Transwell assays in vitro and in a peritoneal xenograft nude mouse model in vivo. EDTA and trypsin were utilized to investigate the attachment ability of these cells. Moreover, the expression of epithelial mesenchymal transition (EMT) markers (β-catenin, Slug, vimentin, Snail, claudin, E-cadherin and N-cadherin) was assessed by western blotting and immunofluorescence in ES-2 and SKOV3 cells. Furthermore, β-hCG and EMT markers were evaluated in human ovarian cancer specimens by IHC. The results showed that overexpression of β-hCG clearly promoted migration and invasion in ES-2 and SKOV3 cells (P<0.05) and facilitated metastasis in peritoneal xenografts, while silencing of β-hCG led to the opposite effect. Moreover, β-hCG was closely associated with cell morphology, attachment ability and EMT marker expression in ES-2 and SKOV3 cells and human ovarian cancer specimens. Upregulation of β-hCG promoted cells from an epithelial-like morphology to a mesenchymal-like phenotype, decreased the adhesion ability (P<0.05), and reduced the expression of epithelial markers (E-cadherin) while inducing the expression of mesenchymal markers (vimentin, N-cadherin, β-catenin and Slug). Furthermore, the converse effects were confirmed by knockdown of β-hCG. These findings strongly suggest that β-hCG may regulate metastasis of ovarian cancer through EMT, and it may become a new target for therapeutic intervention.

Epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy, and its vulnerability to metastasis contributes to the poor outcomes of EOC patients. Long noncoding RNAs (lncRNAs) were verified to play a pivotal role in EOC metastasis. However, the potential role of lncRNA membraneassociated guanylate kinase inverted 1 (MAGI1) intronic transcript (MAGI1-IT1) in EOC is largely unknown. In this study, the function and mechanisms of MAGI1-IT1 in EOC metastasis were explored profoundly. First, MAGI1-IT1 expression was found to be significantly decreased in overexpressing miR-200a EOC cells. Second, MAGI1-IT1 expression was remarkably increased in metastatic EOC tissues, and high MAGI1-IT1 was dramatically associated with EOC FIGO III-IV stage; in addition, MAGI1-IT1 might be related to EOC dissemination via epithelial-mesenchymal transition (EMT). Next, a series of gain-and loss-of-function assays verified that, although MAGI1-IT1 has no significant role in EOC proliferation and subcutaneous xenograft growth, the upregulation of MAGI1-IT1 can remarkably facilitate EOC EMT phenotype, cells migration and invasion ability and intraperitoneal metastasis in nude mice, while downregulation of MAGI1-IT1 led to the opposite effect in vitro. Moreover, MAGI1-IT1 was validated to promote EOC metastasis through upregulation of ZEB1 and ZEB2 by competitively binding miR-200a, and the restrictive effects of MAGI1-IT1 depletion on EOC metastasis could be reversed by inhibition of miR-200a and upregulation of ZEB1 and ZEB2. Collectively, these results suggest that MAGI1-IT1 may work as a ceRNA in promoting EOC metastasis through miR-200a and ZEB1/2 and may be a potential therapeutic target for EOC.