MicroRNA-9 promotes tumorigenesis and mediates sensitivity to cisplatin in primary epithelial ovarian cancer cells

Silencing of lncRNA DLEU1 inhibits tumorigenesis of ovarian cancer via regulating miR-429/TFAP2A axis

Long non-coding RNAs (lncRNAs) are known as crucial regulators in the development of OC. In the current study, we aim to explore the function and molecular mechanism of lncRNA DLEU1 in OC. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to determine the expression of DLEU1, miR-429, and TFAP2A in OC cells and tissues. The relationship among DLEU1, miR-429, and TFAP2A was tested by dual-luciferase reporter (DLR) assay. Besides, the proliferative, migratory and invasive abilities of OC cells were analyzed by MTT, wound healing, and transwell assays, respectively. Western blot was performed to determine the protein expression of TFAP2A. The expression of lncRNA DLEU1 and TFAP2A were upregulated, and miR-429 was downregulated in OC tissues. Silencing of DLEU1 inhibited the proliferation, migration, and invasion of OC cells. Bioinformation and DLR assay showed that DLEU1 acted as the sponge for miR-429. Moreover, miR-429 could directly target TFAP2A and inhibit the proliferation, migration, and invasion of OC cells. Moreover, we observed a negative correlation between miR-429 and DLEU1, and between miR-429 and TFAP2A in OC tissues. The transfection of miR-429 inhibitor or pcDNA-TFAP2A reversed the inhibitory effects of si-DLEU1 on the proliferation, migration, and invasion of OC cells. Silencing of DLEU1 inhibited the proliferation, migration, and invasion of OC cells by regulating miR-429/TFAP2A axis, indicating a potential therapeutic target for OC.

LncRNA NEAT1 enhances the resistance of anaplastic thyroid carcinoma cells to cisplatin by sponging miR‑9‑5p and regulating SPAG9 expression

Anaplastic thyroid carcinoma (ATC) has a poor prognosis due to its resistance to all conventional treatments. The long non-coding RNA (lncRNA) nuclear paraspeckle assembly transcript 1 (NEAT1) serves a critical role in cancer chemoresistance; however, whether NEAT1 is associated with chemoresistance of ATC remains unclear. In the present study, reverse transcription-quantitative PCR assays were performed to detect the expression levels of NEAT1, microRNA (miR)-9-5p and sperm-associated antigen 9 (SPAG9). Western blot analysis was conducted to assess the protein expression levels of p62, microtubule-associated proteins 1A/1B light chain 3B and SPAG9. Cell proliferation was detected using the Cell Counting kit-8 assay, and cell apoptosis was determined by flow cytometry. Dual-luciferase reporter and RNA immunoprecipitation assays were performed to verify the interaction between NEAT1 and miR-9-5p, or miR-9-5p and SPAG9. Furthermore, an animal model was used to investigate the regulatory effects of NEAT1 on cisplatin (DDP)-resistance in tumors in vivo. The present results demonstrated that NEAT1 was upregulated in ATC tissues and cell lines, and NEAT1 silencing resulted in decreased DDP-resistance of ATC cells. In addition, NEAT1 suppressed miR-9-5p expression by binding to miR-9-5p and SPAG9 was a direct target of miR-9-5p. miR-9-5p overexpression sensitized ATC cells to DDP. Notably, NEAT1 silencing exerted its inhibitory effect on DDP-resistance of ATC via the miR-9-5p/SPAG9 axis in vitro and in vivo. In conclusion, the present study demonstrated that NEAT1 silencing ameliorated DDP-resistance of ATC, at least in part by reducing miR-9-5p sponging and regulating SPAG5 expression; therefore, NEAT1 may be considered a potential therapeutic target of ATC.

miR‑210‑3p regulates cell growth and affects cisplatin sensitivity in human ovarian cancer cells via targeting E2F3

The potential role of microRNA (miR)‑210‑3p in carcinogenesis and the cisplatin sensitivity of ovarian cancer were evaluated in the present study. The relative expression levels of miR‑210‑3p in cisplatin‑sensitive SKOV‑3 cells and cisplatin‑resistant SKOV‑3/DDP cells were determined using reverse transcription‑quantitative polymerase chain reaction analysis. miR‑210‑3p mimics and inhibitors were transfected into SKOV‑3/DDP cells. Cell Counting Kit‑8, scratch and Transwell invasion assays and flow cytometry were conducted to evaluate the role of miR‑210‑3p in ovarian cancer cells. A luciferase reporter assay was used to verify the association between miR‑210‑3p and E2F transcription factor 3 (E2F3). Drug sensitivity was evaluated by treating the cells with cisplatin. The expression level of miR‑210‑3p was lower in SKOV‑3/DDP cells than in SKOV‑3 cells. Compared with the untransfected control, SKOV‑3 cells transfected with miR‑210‑3p exhibited a significantly higher survival rate. The overexpression of miR‑210‑3p inhibited SKOV‑3/DDP cell proliferation, migration and invasion, and promoted cell apoptosis. By contrast, the inhibition of miR‑210‑3p promoted cell migration and invasion. The luciferase reporter assay confirmed that E2F3 was a direct target gene of miR‑210‑3p. Cisplatin treatment resulted in a sharp decrease in the survival rate of SKOV‑3/DDP cells transfected with the miR‑210‑3p mimics. The decrease in cell survival rate caused by the overexpression of miR‑210‑3p was rescued by the overexpression of E2F3 in SKOV‑3/DDP cells. Taken together, these results suggest that miR‑210‑3p may act as a tumor suppressor in ovarian cancer cells and affect the sensitivity of cells to cisplatin by directly targeting E2F3. This indicates its potential use as a therapeutic target for improving drug resistance in ovarian cancer.

MicroRNA-9 functions as a tumor suppressor and enhances radio-sensitivity in radio-resistant A549 cells by targeting neuropilin 1

Radiotherapy is commonly used to treat lung cancer but may not kill all cancer cells, which may be attributed to the radiotherapy resistance that often occurs in non-small cell lung cancer (NSCLC). At present, the molecular mechanism of radio-resistance remains unclear. Neuropilin 1 (NRP1), a co-receptor for vascular endothelial growth factor (VEGF), was demonstrated to be associated with radio-resistance of NSCLC cells via the VEGF-phosphoinositide 3-kinase-nuclear factor-κB pathway in our previous study. It was hypothesized that certain microRNAs (miRs) may serve crucial functions in radio-sensitivity by regulating NRP1. Bioinformatics predicted that NRP1 was a potential target of miR-9, and this was validated by luciferase reporter assays. Functionally, miR-9-transfected A549 cells exhibited a decreased proliferation rate, increased apoptosis rate and attenuated migratory and invasive abilities. Additionally, a high expression of miR-9 also significantly enhanced the radio-sensitivity of A549 cells in vitro and in vivo. These data improve understanding of the mechanisms of cell radio-resistance, and suggest that miR-9 may be a molecular target for the prediction of radio-sensitivity in NSCLC.

Molecular mechanisms of drug resistance in ovarian cancer

Ovarian cancer is the most lethal malignancy among the gynecological cancers, with a 5-year survival rate, mainly due to being diagnosed at advanced stages, recurrence and resistance to the current chemotherapeutic agents. Drug resistance is a complex phenomenon and the number of known involved genes and cross-talks between signaling pathways in this process is growing rapidly. Thus, discovering and understanding the underlying molecular mechanisms involved in chemo-resistance are crucial for management of treatment and identifying novel and effective drug targets as well as drug discovery to improve therapeutic outcomes. In this review, the major and recently identified molecular mechanisms of drug resistance in ovarian cancer from relevant literature have been investigated. In the final section of the paper, new approaches for studying detailed mechanisms of chemo-resistance have been briefly discussed.

Role of MiRNAs in Inflammatory Bowel Disease

Inflammatory bowel diseases (IBD), mainly including Crohn's disease and ulcerative colitis, are characterized by chronic inflammation of the gastrointestinal tract. Despite improvements in detection, drug treatment and surgery, the pathogenesis of IBD has not been clarified. A number of miRNAs have been found to be involved in the initiation, development and progression of IBD, and they may have the potential to be used as biomarkers and therapeutic targets. Here, we have summarized the recent advances about the roles of miRNAs in IBD and analyzed the contribution of miRNAs to general diagnosis, differential diagnosis and activity judgment of IBD. Furthermore, we have also elaborated the promising role of miRNAs in IBD-related cancer prevention and prognosis prediction.

Clinical validation of chemotherapy predictors developed on global microRNA expression in the NCI60 cell line panel tested in ovarian cancer

OBJECTIVE

Ovarian cancer is the leading cause of death among gynecologic malignancies. This is partly due to a non-durable response to chemotherapy. Prediction of resistance to chemotherapy could be a key role in more personalized treatment. In the current study we aimed to examine if microRNA based predictors could predict resistance to chemotherapy in ovarian cancer, and to investigate if the predictors could be prognostic factors for progression free and overall survival.

METHODS

Predictors of chemotherapy-resistance were developed based on correlation between miRNA expression and differences in measured growth inhibition in a variety of human cancer cell lines in the presence of Carboplatin, Paclitaxel and Docetaxel. These predictors were then, retrospectively, blindly validated in a cohort of 170 epithelial ovarian cancer patients treated with Carboplatin and Paclitaxel or Docetaxel as first line treatment.

RESULTS

In a multivariate cox proportional analysis the predictors of chemotherapy-resistance were not able to predict time to progression after end of chemotherapy (hazard ratio: 0.64, 95% CI: 0.36-1.12, P = 0.117). However, in a multivariate logistic analysis, where time to progression was considered as either more or less than 6 months, the predictors match clinical observed chemotherapy-resistance (odds ratio: 0.19, 95% CI: 0.05-0.73, P = 0.015). Neither univariate nor multivariate, time-dependent, cox analysis for progression free survival (PFS) or overall survival (OS) in all 170 patients showed to match predicted resistance to chemotherapy (PFS: hazard ratio: 0.69, 95% CI: 0.40-1.19, P = 0.183, OS: hazard ratio: 0.76, 95% CI: 0.42-1.40, P = 0.386).

CONCLUSION

In the current study, microRNA based predictors of chemotherapy-resistance did not demonstrate any convincing correlation to clinical observed chemotherapy-resistance, progression free survival, or overall survival, in patients with epithelial ovarian cancer. However the predictors did reflect relapse more or less than 6 months.

Interactions between anticancer active platinum complexes and non-coding RNAs/microRNAs

Platinum(II) complexes such as cisplatin, carboplatin and oxaliplatin are clinically approved for the therapy of various solid tumors. Challenging pathogenic properties of cancer cells and the response of cancers towards platinum-based drugs are strongly influenced by non-coding small RNA molecules, the microRNAs (miRNAs). Both increased platinum activity and formation of tumor resistance towards platinum drugs are controlled by miRNAs. This review gives an overview of the interactions between platinum-based drugs and miRNAs, and their influence on platinum activity in various cancer types is discussed.

Experimental study on the inhibition effect of miR-106a inhibitor on tumor growth of ovarian cancer xenografts mice

OBJECTIVE

To study the inhibition effect of miR-106a inhibitor on tumor growth of ovarian cancer xenografts mice.

METHODS

BALB/c mice were selected as experimental animals, ovarian cancer SKOV-3 cells transfected with miR-106a inhibitor and its negative control were inoculated subcutaneously, intratumoral injection of miR-106a inhibitor and its negative control were continued after tumor formation, and they were enrolled as treatment group and model group, respectively. Tumor volume and weight as well as Ki-67 and programmed cell death 4 (PDCD4) expression were determined; miR-106a inhibitor and its negative control as well as miR-106a mimic and its negative control were transfected into SKOV-3 cells, and expression of PDCD4 in cells was determined.

RESULTS

Tumor tissue volume and weight as well as mRNA expression and protein expression of Ki-67 in treatment group were significantly lower than those in the model group while mRNA expression and protein expression of PDCD4 were significantly higher than those in the model group; transfection of miR-106a mimic could decrease mRNA expression and protein expression of PDCD4 in SKOV-3 cells, and transfection of miR-106a inhibitor could increase mRNA expression and protein expression of PDCD4 in SKOV-3 cells.

CONCLUSIONS

Transfection of miR-106a inhibitor can inhibit the growth of tumor in ovarian cancer xenografts mice through increasing the expression of PDCD4.

A Comparative Analysis of Genetic and Epigenetic Events of Breast and Ovarian Cancer Related to Tumorigenesis

Breast cancer persists as the most common cause of cancer death in women worldwide. Ovarian cancer is also a significant source of morbidity and mortality, as the fifth leading cause of cancer death among women. This reflects the continued need for further understanding and innovation in cancer treatment. Though breast and ovarian cancer usually present as distinct clinical entities, the recent explosion of large-scale -omics research has uncovered many overlaps, particularly with respect to genetic and epigenetic alterations. We compared genetic, microenvironmental, stromal, and epigenetic changes common between breast and ovarian cancer cells, as well as the clinical relevance of these changes. Some of the most striking commonalities include genetic alterations of BRCA1 and 2, TP53, RB1, NF1, FAT3, MYC, PTEN, and PIK3CA; down regulation of miRNAs 9, 100, 125a, 125b, and 214; and epigenetic alterations such as H3K27me3, H3K9me2, H3K9me3, H4K20me3, and H3K4me. These parallels suggest shared features of pathogenesis. Furthermore, preliminary evidence suggests a shared epigenetic mechanism of oncogenesis. These similarities, warrant further investigation in order to ultimately inform development of more effective chemotherapeutics, as well as strategies to circumvent drug resistance.

Carboplatin with Decitabine Therapy, in Recurrent Platinum Resistant Ovarian Cancer, Alters Circulating miRNAs Concentrations: A Pilot Study

Objective

Plasma miRNAs represent potential minimally invasive biomarkers to monitor and predict outcomes from chemotherapy. The primary goal of the current study—consisting of patients with recurrent, platinum-resistant ovarian cancer—was to identify the changes in circulating miRNA concentrations associated with decitabine followed by carboplatin chemotherapy treatment. A secondary goal was to associate clinical response with changes in circulating miRNA concentration.

Methods

We measured miRNA concentrations in plasma samples from 14 patients with platinum-resistant, recurrent ovarian cancer enrolled in a phase II clinical trial that were treated with a low dose of the hypomethylating agent (HMA) decitabine for 5 days followed by carboplatin on day 8. The primary endpoint was to determine chemotherapy-associated changes in plasma miRNA concentrations. The secondary endpoint was to correlate miRNA changes with clinical response as measured by progression free survival (PFS).

Results

Seventy-eight miRNA plasma concentrations were measured at baseline (before treatment) and at the end of the first cycle of treatment (day 29). Of these, 10 miRNAs (miR-193a-5p, miR-375, miR-339-3p, miR-340-5p, miR-532-3p, miR-133a-3p, miR-25-3p, miR-10a-5p, miR-616-5p, and miR-148b-5p) displayed fold changes in concentration ranging from -2.9 to 4 (p<0.05), in recurrent platinum resistant ovarian cancer patients, that were associated with response to decitabine followed by carboplatin chemotherapy. Furthermore, lower concentrations of miR-148b-5p after this chemotherapy regimen were associated (P<0.05) with the PFS.

Conclusions

This is the first report demonstrating altered circulating miRNA concentrations following a combination platinum plus HMA chemotherapy regiment. In addition, circulating miR-148b-5p concentrations were associated with PFS and may represent a novel biomarker of therapeutic response, with this chemotherapy regimen, in women with recurrent, drug-resistant ovarian cancer.