MicroRNA-935 acts as a prognostic marker and promotes cell proliferation, migration, and invasion in colorectal cancer

METTL3 promotes choriocarcinoma progression by activating the miR-935/GJA1 pathway in an m6A-dependent manner

The emerging role of microRNA-935 (miR-935) in modulating cancer progression has been recognized. However, its role in regulating choriocarcinoma (CCA) development and progression remains unknown. The present work aims to reveal the effect of miR-935 on CCA cell tumor properties and the related mechanism. The RNA expression of methyltransferase 3, N6-adenosine-methyltransferase complex catalytic subunit (METTL3), miR-935, and gap junction protein alpha 1 (GJA1) was detected by quantitative real-time polymerase chain reaction. Protein expression of GJA1, Ki67, and METTL3 was measured by western blotting and immunohistochemistry assays. CCK-8 and colony formation were used to analyze cell proliferation. Transwell assays were performed to assess cell migration and invasion. Angiogenesis was investigated by tube formation assay. Xenograft mouse model assay was used to determine miR-935-mediated effect on tumor formation in vivo. The luciferase reporter assay and RNA pull-down assay were used to verify the relationship between miR-935 and GJA1. MeRIP assay was used to analyze the m6A methylation of pri-miR-935. MiR-935 expression was significantly upregulated in CCA tissues and cells when compared with control groups. MiR-935 overexpression promoted CCA cell proliferation, migration, invasion, and tube formation and tumor tumorigenesis in vitro and in vivo, but miR-935 knockdown showed the opposite effects. In addition, miR-935 targeted GJA1 and mediated CCA cell tumor properties by negatively regulating GJA1 expression. METTL3 promoted miR-935 maturation by inducing m6A methylation of pri-miR-935, and its overexpression contributed to CCA cell tumor properties through the regulation of miR-935. METTL3 promoted choriocarcinoma progression by m6A-dependently activating the miR-935/GJA1 pathway.

Identification of a Twelve-microRNA Signature with Prognostic Value in Stage II Microsatellite Stable Colon Cancer

We aimed to identify and validate a set of miRNAs that could serve as a prognostic signature useful to determine the recurrence risk for patients with COAD. Small RNAs from tumors of 100 stage II, untreated, MSS colon cancer patients were sequenced for the discovery step. For this purpose, we built an miRNA score using an elastic net Cox regression model based on the disease-free survival status. Patients were grouped into high or low recurrence risk categories based on the median value of the score. We then validated these results in an independent sample of stage II microsatellite stable tumor tissues, with a hazard ratio of 3.24, (CI_95% = 1.05-10.0) and a 10-year area under the receiver operating characteristic curve of 0.67. Functional analysis of the miRNAs present in the signature identified key pathways in cancer progression. In conclusion, the proposed signature of 12 miRNAs can contribute to improving the prediction of disease relapse in patients with stage II MSS colorectal cancer, and might be useful in deciding which patients may benefit from adjuvant chemotherapy.

The Profile of MicroRNA Expression and Potential Role in the Regulation of Drug-Resistant Genes in Doxorubicin and Topotecan Resistant Ovarian Cancer Cell Lines

Epithelial ovarian cancer has the highest mortality among all gynecological malignancies. The main reasons for high mortality are late diagnosis and development of resistance to chemotherapy. Resistance to chemotherapeutic drugs can result from altered expression of drug-resistance genes regulated by miRNA. The main goal of our study was to detect differences in miRNA expression levels in two doxorubicin (DOX)- and two topotecan (TOP)-resistant variants of the A2780 drug-sensitive ovarian cancer cell line by miRNA microarray. The next aim was to recognize miRNAs as factors responsible for the regulation of drug-resistance genes. We observed altered expression of 28 miRNA that may be related to drug resistance. The upregulation of miR-125b-5p and miR-935 and downregulation of miR-218-5p was observed in both DOX-resistant cell lines. In both TOP-resistant cell lines, we noted the overexpression of miR-99a-5p, miR-100-5p, miR-125b-5p, and miR-125b-2-3p and decreased expression of miR-551b-3p, miR-551b-5p, and miR-383-5p. Analysis of the targets suggested that expression of important drug-resistant genes such as the collagen type I alpha 2 chain (COL1A2), protein Tyrosine Phosphatase Receptor Type K (PTPRK), receptor tyrosine kinase—EPHA7, Roundabout Guidance Receptor 2 (ROBO2), myristoylated alanine-rich C-kinase substrate (MARCK), and the ATP-binding cassette subfamily G member 2 (ABCG2) can be regulated by miRNA.

MicroRNA-935 Directly Targets FZD6 to Inhibit the Proliferation of Human Glioblastoma and Correlate to Glioma Malignancy and Prognosis

MicroRNAs (miRNAs) are involved in human glioblastoma (GB). MiR-935 has been reported to have both tumor-inhibiting and tumorigenesis effects, but its role in GB remains unclear. Because of the high mortality and morbidity associated with the malignancy of GB, a deeper understanding of the molecular crosstalk that occurs in GB is needed to identify new potential targets for treatment. At present, the mechanism of GB at the molecular level is not fully understood. With the aid of bioinformatic analysis, miR-935 was significantly downregulated in GB, and it presented a poorer outcome. In the glioma cell line and in the nude mice model, the miR-935 inhibited cell proliferation by modulating cell circles in vitro and in vivo. Then, the target genes of miR-935 were analyzed by using the online database, and the direct binding was tested with a luciferase analysis. FZD6 was found to be the direct target of miR-935. The effect of miR-935 was recovered by the overexpression of FZD6 in vitro. In addition, the negative correlation of miR-935 and the expression of FZD6 were confirmed in our clinical samples, and the expression of FZD6 has a strong correlation with tumor malignancy and prognosis. This study showed that miR-935 directly inhibited the expression of FZD6 and inhibited the cell proliferation, thereby suppressing the development of GB, suggesting that miR-935 is a cancer suppressor miRNA and may become a prognostic biomarker or a promising potential therapeutic target for human GBs.

The role of SOX family transcription factors in gastric cancer

Gastric cancer (GC) is a leading cause of death worldwide. GC is the third-most common cause of cancer-related death after lung and colorectal cancer. It is also the fifth-most commonly diagnosed cancer. Accumulating evidence has revealed the role of signaling networks in GC progression. Identification of these molecular pathways can provide new insight into therapeutic approaches for GC. Several molecular factors involved in GC can play both onco-suppressor and oncogene roles. Sex-determining region Y (Sry)-box-containing (SOX) family members are transcription factors with a well-known role in cancer. SOX proteins can bind to DNA to regulate cellular pathways via a highly conserved domain known as high mobility group (HMG). In the present review, the roles of SOX proteins in the progression and/or inhibition of GC are discussed. The dual role of SOX proteins as tumor-promoting and tumor-suppressing factors is highlighted. SOX members can affect upstream mediators (microRNAs, long non-coding RNAs and NF-κB) and down-stream mediators (FAK, HIF-1α, CDX2 and PTEN) in GC. The possible role of anti-tumor compounds to target SOX pathway members in GC therapy is described. Moreover, SOX proteins may be used as diagnostic or prognostic biomarkers in GC.

MiR-935/HIF1α Feedback Loop Inhibits the Proliferation and Invasiveness of Glioma

Objective

The biological functions and molecular mechanisms of miR-935 have been widely investigated in various types of cancer. The aim of the present study was to explore the function of miR-935 in glioma.

Methods

Bioinformatic analysis and quantitative real-time fluorescent PCR (qRT-PCR) were used to determine the expression of miR-935 in glioma tissues and glioma cell lines. Chi-square test was performed to analyze the relationship between the expression of miR-935 and clinical traits. CCK-8 assay, colony formation assay, cell cycle analysis and subcutaneous tumorigenesis model in nude mice were conducted to determine the effects of miR-935 on the proliferation of glioma cells both in vitro and in vivo. Wound healing and transwell assays were used to detect the effects of miR-935 on the migration and invasion of glioma cells in vitro. The relationship between miR-935 and HIF1α was analyzed using bioinformatics, luciferase reporter assay and Western blotting.

Results

The expression of miR-935 was lower in glioma tissues than in the adjacent tissues, and in cell lines than in the normal human astrocytes (NHAs), and the low expression levels of miR-935 predicted a poor outcome. Exogenous overexpression of miR-935 inhibited the proliferation of glioma cells both in vitro and in vivo, and suppressed the migration and invasion of glioma cells in vitro. HIF1α was identified as the target of miR-935, whereas miR-935 overexpression decreased the expression of HIF1α and its target genes VEGF, MCL1 and GLUT1. Strikingly, overexpression of HIF1α significantly decreased the expression of miR-935, whereas silencing HIF1α increased the expression of miR-935. Similarly, HIF1α overexpression remarkably reversed the inhibitory effects of miR-935 on the proliferation, migration and invasion of glioma cells.

Conclusion

Overall, present study reveals the presence of miR-935/HIF1α feedback loop in glioma, which inhibits the development of glioma. This feedback loop may be a potential target for the treatment of glioma.

Identification of miR-135b as a novel regulator of TGFβ pathway in gastric cancer

Gastric cancer (GC) is a common malignant tumor worldwide, with a high incidence and low survival rate. The transforming growth factor-beta (TGFβ) signaling pathway usually plays a tumor-suppressive role and is normally quietened in GC. The downregulation of transforming growth factor-beta receptor II (TGFBR2) affects TGFβ signaling pathway, which exerts an immense effect on tumor cell proliferation and metastasis. Although the effect of the TGFβ signaling pathway on cancer cells is well studied, little is known about the mechanism by which TGFBR2 expression is downregulated. Here, we showed that TGFBR2 protein, but not TGFBR2 mRNA, was consistently downregulated in GC, suggesting that post-transcriptional mechanism is involved in the regulation of TGFBR2. Bioinformatics analysis and luciferase reporter analysis proved that miR-135b combines precisely with the 3'-UTR of TGFBR2 mRNA. EdU assays and cell migration assays respectively showed that miR-135b overexpression induced the growth and invasion of GC cells. However, the overexpression of TGFBR2 had the opposite effect. TGFBR2 acted as the direct target for miR-135b and was downregulated in gastric cancer cells. Therefore, miR-135b promotes proliferation and migration of GC cells by negatively regulating TGFBR2 expression, displaying an oncomiR effect. Altogether, this conclusive evidence supported that miR-135b mediates the progression of GC by targeting TGFBR2 and miR-135b/TGFBR2 axis can be used in future targeted therapy for GC.

MiR-935 Promotes Clear Cell Renal Cell Carcinoma Migration and Invasion by Targeting IREB2

Purpose

Clear cell renal cell carcinoma (ccRCC) has the highest rate of metastasis and invasion in RCC and is the third most common adult urinary malignancy. miRNA may serve a critical role in human cancer development and progression, has been confirmed to play a pivotal role in RCC cell invasion and migration. Since miR‑935 had been verified to be an oncogene or tumor suppressor in various cancers, the role of miR‑935 in RCC was unclear.

Methods

Real-time quantitative polymerase chain reaction (qRT-PCR) was used to verify miR-935 expression. CCK-8 assay, wound healing assay and transwell assay were used to investigate the cell proliferation, migration and invasion of miR-935. Receiver operating characteristic (ROC) curve analysis was applied to discriminate different clinical classifications. Gain or loss of function approaches were used to investigate the cell proliferation, migration and invasion of miR-935 in vitro. Bioinformatics analysis and dual-luciferase reporter assay were used to identify the target of miR-935.

Results

MiR-935 had a higher expression level in RCC cells and cancer tissues. MiR-935 mimics promoted cell proliferation, migration and invasion, and miR-935 inhibitor inhibited cell inhibit malignancy of cancer cells. Bioinformatics analysis and dual-luciferase reporter assay identified iron-responsive element-binding protein 2 (IREB2) as a direct target of miR-935. qRT-PCR showed IREB2 expression was downregulated in ccRCC cancer tissues and high IREB2 expression had a longer overall survival (OS) and disease-free survival (DFS). Silencing IREB2 could reverse the function of miR-935 inhibitor on cell proliferation and metastasis in renal cancer cells.

Conclusion

The study indicated that miR-935 may act as an oncomiRNA and influenced migration and invasion progress of ccRCC by targeting IREB2. Oncogene miR-935 may be a molecular marker and uncover new strategies for ccRCC.