MicroRNA-224 is implicated in lung cancer pathogenesis through targeting caspase-3 and caspase-7

MicroRNA-223 Promotes Tumor Progression in Lung Cancer A549 Cells via Activation of the NF-κB Signaling Pathway

THIS ARTICLE WAS WITHDRAWN BY THE PUBLISHER IN NOVEMBER 2020

Over-Expressed miR-224 Promotes the Progression of Cervical Cancer via Targeting RASSF8

Cervical cancer is the most common cause of cancer-related deaths in women from developing countries. Identification of novel prognostic predictors or therapeutic targets may improve patient prognosis. In the current study, we demonstrated by real-time PCR that miR-224 expression was significantly upregulated (1.82-fold, P = 0.0025) in cervical cancer tissues (n = 126) compared with in normal cervical tissues (n = 64). Higher expression of miR-224 was significantly associated with poorer prognostic factors, including advanced FIGO stage, nodal metastasis, larger tumor size, vascular involvement and deep stromal invasion (all P < 0.05). Enforced expression of miR-224 promoted cell proliferation, migration and invasion in SiHa and CaSki cancer cell lines. Bioinformatic analysis indicated that RASSF8 (RAS-association domain family 8) was a potential target of miR-224. Western blot analysis and luciferase reporter assay showed that overexpressed miR-224 inhibited RASSF8 protein expression and decreased the activity of a luciferase reporter containing the 3′ untranslated region (UTR) of RASSF8, respectively. Further, RASSF8 knockdown by specific RNAi showed similar effects in cervical cancer cells transfected with miR-224 mimic. Our findings suggest that miR-224 directly targets RASSF8 and thereby acts as a tumor promoter in cervical cancer progression.

MiR-155 and its functional variant rs767649 contribute to the susceptibility and survival of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) ranks the fourth common cancer and the third common cause of cancer mortality among Chinese population. The development of hepatocellular carcinoma (HCC) were confirmed to be involved in complex interactions between environmental and genetic factors. MicroRNAs (miRNAs) have been found to play an important role in tumorigenesis and metastasis. Emerging evidence suggested that upregulation of miR-155, one of the best characterized miRNAs, could serve as a promising marker for the diagnosis and prognosis of many cancers, except for HCC. In current we tested the hypothesis that functional variant rs767649 located in the flanking region of miR-155 gene contributes to the development and survival of HCC. We identified that functional variant rs767649 in miR-155 regulation region was associated with risk and survival of HCC. The minor allele of rs767649 was significantly associated with an increased risk of HCC (OR=1.23, 95% CI=1.11-1.36, P = 7.97x10-5). The genotype TT of rs767649 was significantly associated with a 1.94 fold poor survival of HCC (HR=1.94, 95% CI=1.01-3.79), while 1.15 fold for genotype AT (HR=1.15, 95% CI=1.06-1.25). Results showed that miR-155 was highly overexpressed in HCC tissues, compared with the adjacent normal tissues (P<0.001). The allele T contributes to higher expression of miR-155 in both the HCC tissues and the adjacent non-tumor tissues (P< 0.01). Our findings suggested that miR-155 and its functional variant rs767649 might contribute to the increased risk and poor prognosis of HCC, highlighting the importance of miR-155 in the prevention and prognosis of HCC.

miR-224-3p inhibits autophagy in cervical cancer cells by targeting FIP200

Cervical cancer (CC) is a malignant solid tumor, which is one of the main causes of morbidity and mortality in women. Persistent High-risk human papillomavirus (hrHPV) infection is closely related to cervical cancer and autophagy has been suggested to inhibit viral infections. miRNAs have been reported to regulate autophagy in many solid tumors with many studies implicating miR-224-3p in the regulation of autophagy. In this study, we performed a miRNA microarray analysis on CC tissues and found that a large number of miRNAs with differential expressions in hrHPV-infected tissues. We identified miR-224-3p as a candidate miRNA selectively up regulated in HPV-infected tissues and cell lines. Further analysis revealed that miR-224-3p regulates autophagy in cervical cancer tissues and cell lines. While the overexpression of miR-224-3p inhibits autophagy in HPV-infected cells, knocking down endogenous miR-224-3p increases autophagy activity in the same cells. In addition, we found that miR-224-3p directly inhibits the expression of autophagy related gene, FAK family-interacting protein of 200 kDa (FIP200). In summary, we found that miR-224-3p regulates autophagy in hrHPV-induced cervical cancer cells through targeting FIP200 expression.

Aberrantly expressed microRNAs in bladder cancer and renal cell carcinoma

Bladder cancer (BC) and renal cell carcinoma (RCC) are frequently diagnosed urinary tract cancers. Recently developed molecular-targeted therapies for RCC have shown remarkable therapeutic efficacy; however, no targeted therapeutics are currently approved for the treatment of BC, and few effective treatment options exist. Current studies have shown that small noncoding RNA molecules have major roles in cancer cells. MicroRNAs (miRNAs) are endogenous small noncoding RNA molecules that regulate protein-/nonprotein-coding RNAs in human cells. A large body of evidence suggests that aberrantly expressed miRNAs are deeply involved in the pathogenesis of human cancers. In this paper, we review recently published miRNA expression signatures of BC and RCC. We focus on downregulated or upregulated miRNAs in multiple signatures and discuss putative target genes of miRNAs. Comparisons of RCC and BC expression signatures revealed that the two types of cancer showed opposite expression patterns for miR-200 family miRNAs (i.e., miR-141/200c and miR-200a/200b/429). We discuss in silico analysis of genes targeted by miR-200 family miRNAs and the molecular mechanisms underlying BC and RCC.

microRNA regulators of apoptosis in cancer

This brief review summarizes our current knowledge on the microRNAs that regulate apoptosis machinery and are potentially involved in the dysregulation or deregulation of apoptosis, a well known hallmark of cancer. microRNAs are critical regulators of the most important cellular processes, including apoptosis. Expression of microRNAs is found to be dysregulated in many malignancies, leading to apoptosis inhibition in cancer, or resistance to current therapies. To date, there are over 80 microRNAs directly involved in apoptosis regulation or dysregulation that can impact cancer detection, initiation, progression, invasion, metastasis or resistance to anti-cancer therapy. Development of microRNA-based therapeutic strategies is now taking shape in the clinic. Thus, these microRNAs represent potential targets or tools for cancer therapy in the future.

miR-935 promotes gastric cancer cell proliferation by targeting SOX7

Gastric cancer is the most common cancer in the world, miRNAs have been demonstrated to play critical role in the development and progression of gastric cancer, such as miR-7, miR-217 and miR-335. Here, we found miR-935 was upregulated in gastric cancer tissues and cells. Overexpression of miR-935 promoted cell proliferation and tumorigenesis in vitro determined by MTT analysis, colony formation analysis, BrdU cell proliferation analysis and soft agar growth analysis, knockdown of miR-935 reduced these effects. Tumor suppressor sex-determining region Y-box 7 (SOX7) was the direct target of miR-935, overexpression of miR-935 inhibited SOX7 expression, but promoted the levels CCND1 and C-MYC which promotes cell proliferation and tumorigenesis, knockdown of miR-935 increased SOX7 level, and inhibited CCND1 and C-MYC expression. Synchronous knockdown of miR-935 and SOX7 promoted cell proliferation and tumorigenesis in vitro, confirming miR-935 regulated gastric cancer cell proliferation by inhibiting SOX7. In summary, we found miR-935 contributed to cell proliferation of gastric cancer through targeting SOX7.

Galectin-9: An anticancer molecule for gallbladder carcinoma

Gallbladder cancer (GBC) is the most common and aggressive type of biliary tract cancer. There are various histological types of GBC, and the vast majority of GBC cases are adenocarcinomas. Squamous and adenosquamous carcinomas are rare GBC subtypes that are traditionally considered to be more aggressive and to be associated with a poorer prognosis than adenocarcinoma. Galectin-9 (Gal-9), a tandem-repeat-type galectin, has been reported to induce apoptosis-mediated elimination of various cancers, including hepatocellular carcinoma, cholangiocarcinoma, and hematologic malignancies. Therefore, we investigated the antitumor effects of Gal-9 on GBC in vitro and in vivo. In our in vitro experiments, Gal-9 suppressed cell proliferation in various GBC cell lines but not in the OCUG-1 cell line, which represents a poorly differentiated type of adenosquamous carcinoma. Gal-9 induced the apoptosis of Gal-9-sensitive GBC cells by increasing the levels of caspase-cleaved keratin 18 and phosphorylated p53. However, Gal-9 did not affect the expression of various cell cycle-related proteins. In addition, Gal-9 suppressed tumor growth by implanted human GBC cells in a xenograft model. Furthermore, Gal-9 induced the phosphorylation of the Ephrin type-B receptor, and the microRNA (miRNA) expression profile was markedly altered by Gal-9. Based on these results, various miRNAs might contribute to the suppression of tumor growth. Our data reveal that Gal-9 suppresses the growth of GBC, possibly by inducing apoptosis and altering miRNA expression. Thus, Gal-9 might serve as a therapeutic agent for the treatment of GBC.