Long noncoding RNAs (lncRNAs) have been implicated in the regulation of resistance to radiotherapy in cervical cancer, which is a type of gynecological disease with high mortality in women around the world. Hence, our purpose is to delineate the involvement of LINC00958 in regulating cell sensitivity to radiotherapy in cervical cancer. LINC00958 expression in cervical cancer was assayed, followed by verification of the relationship among LINC00958, microRNA-5095 (miR-5095) and ribonucleotide reductase subunit M2 (RRM2). Hela cells were transduced with up-/downregulation of miR-5095 or RRM2, or LINC00958 silencing, respectively, and then treated with or without a 6 Gy dose of X-ray irradiation. Then the cell proliferation, apoptosis, survival fraction rate, as well as sensitivity to radiotherapy, were assessed. Finally, xenograft tumor in nude mice was established by transplanting Hela cells transfected with sh-LINC00958 and irradiated with 6 Gy of X-ray. High expression of LINC00958 was revealed in The Cancer Genome Atlas and GeneExpression Profiling Interactive Analysis, as well as in radiation-resistant patients, which was associated with lower sensitivity to radiotherapy in cervical cancer. Moreover, cervical cancer patients with higher LINC00958 expression exhibited a shorter overall survival according to Kaplan-Meier analysis. In addition, LINC00958 could regulate the expression of RRM2 by competing for miR-5095. A combination of radiotherapy with LINC00958 silencing, RRM2 downregulation or miR-5095 overexpression was found to inhibit cervical cancer cell proliferation and tumor growth, while promoting cell apoptosis both in vitro and in vivo. Collectively, our results suggest that LINC00958 could regulate RRM2 by competing to miR-5095, which regulates cell sensitivity to radiotherapy in cervical cancer. K E Y W O R D S cervical cancer, long noncoding RNA LINC00958, microRNA-5095, ribonucleotide reductase subunit M2, sensitivity to radiotherapy 1 | BACKGROUND Cervical cancer, one of the commonest types of gynecological malignancies, presents an increased incidence in the younger population in recent years (Wu et al., 2018). Current treatment approaches for cervical cancer include surgery, radiotherapy and cytotoxic chemotherapy (Lin et al., 2018). However, the 5-year survival rate remains unsatisfactory due to the fact that the majority of the patients with cervical cancer is often diagnosed at an advanced stage with distant and lymph node metastasis occurred (Dong, Wang, Li, & Xiao-Jin, 2018).

Cervical cancer (CC) remains a highly prevalent cancer and mortality globally among women globally. The aim of the present study was to assess the ability of miR-374b to regulate CC cells through JAM-2, whilst exploring whether the underlying mechanism and its relation to the p38/ERK signaling pathway. During the study, microRNA-374b (miR-374b) was observed to have been expressed at a low level among CC tissues. Hence, a series of miR-374b mimics, miR-374b inhibitors, siRNA against JAM-2, SB202190 (an inhibitor for p38), and PD98059 (an inhibitor for ERK) were introduced to treat CC Siha cells and normal cervical Ect1/E6E7 cells. MTT, flow cytometry, scratch test, and transwell assays were applied to determine cell viability, apoptosis, migration, and invasion. The inhibitory role of the p38/ERK signaling pathway was observed in the CC cells treated with miR-374b mimics or siRNA against JAM-2. miR-374b mimic exposure was found to reduce cell viability, migration, and invasion, but induce apoptosis. MiR-374b inhibitor exposure was observed to have induced effects on the CC cells in a contrary manner to those induced by that of the miR-374b mimics. The key findings of the study demonstrated that miR-374b significantly inhibits cell proliferation, migration, and invasion through the blockade of the p38/ERK signaling pathway activation, as well as negatively binding to JAM-2, highlighting its potential as a therapeutic target for CC.

Ovarian cancer characterizes as the fourth leading consequence of death associated with cancer for women. Accumulating evidence underscores the vital roles of microRNAs (miRNAs) in preventing ovarian cancer development. Besides, induction of the phosphatidylinositol-3 kinase/serine/threonine kinase (PI3K/Akt) pathway associated with the ovarian cancer cell migration and invasion. The study aims to examine the effects of miR-15b on the proliferation, apoptosis, and senescence of human ovarian cancer cells by binding to lysophosphatidic acid receptor 3 (LPAR3) with the involvement of the PI3K/Akt pathway. The positive expression of LPAR3 protein was detected by immunohistochemistry. Then the interaction between miR-15b and LPAR3 was examined. The possible role of miR-15b in ovarian cancer was explored using gain-and loss-of-function experiments. Subsequently, the functions of miR-15b on PI3K/Akt pathway, proliferation, migration, invasion, senescence and apoptosis of ovarian cancer cells were assessed. Furthermore, in vivo tumorigenicity assay in nude mice was performed. LPAR3 was overexpressed, whereas miR-15b was poorly expressed in ovarian cancer tissues. LPAR3 is a direct target of miR-15b.Restored miR-15b promoted Bax expression, apoptosis, and senescence, inhibited expression of LPAR3 and Bcl-2, the extent of PI3K and Akt phosphorylation, as well as ovarian cancer cell proliferation, migration, and invasion. Further, tumor growth was observed to be prevented by miR-15b overexpression. Collectively, our study demonstrates that miR-15b represses the proliferation and drives the senescence and apoptosis of ovarian cancer cells through the suppression of LPAR3 and the PI3K/Akt pathway, highlighting an antitumorigenic role of miR-15b.

The functional roles of individual large intervening noncoding RNAs in carcinogenesis and progression of cervical cancer have been uncovered in previous studies. In this study, we aimed to identify the role of long intervening noncoding 00467 (LINC00467) in epithelial-mesenchymal transition (EMT), invasion and migration of cervical cancer cells by regulating miR-107 and kinesin family member 23 (KIF23). Microarray analyses were used to detect cervical cancererelated differentially expressed genes, followed by determination of LINC00467, miR-107, and KIF23 levels and subcellular location of LINC00467. Cervical cancer cells were treated with a series of siRNA and mimics to measure the regulatory role of LINC00467, miR-107, and KIF23 in EMT, cell invasion, migration and proliferation, and tumorigenic ability in vivo and in vitro. LINC00467 and KIF23 were highly expressed, whereas miR-107 was poorly expressed, in cervical cancer. LINC00467 was found to be primarily located in the cytoplasm and function as a competing endogenous RNA against miR-107 to suppress KIF23. Cell proliferation, migration, invasion, and EMT in vitro were inhibited as a result of lentiviral-mediated LINC00467 knockdown and miR-107 overexpression in cervical cancer. In addition, LINC00467 silencing or miR-107 up-regulation repressed tumorigenic ability in xenograft tumor-bearing nude mice in cervical cancer in vivo. LINC00467 silencing or miR-107 up-regulation may serve as novel potential strategies for the treatment of cervical cancer.

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