The role of miRNA125b in the progression of hepatocellular carcinoma

Interaction between miR‑206 and lncRNA MALAT1 in regulating viability and invasion in hepatocellular carcinoma

MicroRNAs (miRNAs) are strongly associated to the progression of hepatocellular carcinoma (HCC), which presents a high potential for diagnosis and treatment; however, the role of miRNAs is still largely unknown. The aim of the present study was to examine the expression and the biological role of miRNA (miR)-206 in the development of HCC, and to identify the underlying molecular mechanism. Results from this study show that miR-206 was significantly downregulated in HCC tissues and cell lines. It was observed that low expression of miR-206 was linked to advanced TNM stage, tumor nodularity and venous infiltration in patients with HCC; low miR-206 expression was associated with shorter survival times. miR-206 overexpression using miR-206 mimics notably decreased the proliferative ability and increased apoptosis of MHCC97-H and HCCLM3 HCC cell lines. Overexpression of miR-206 suppressed invasiveness associated with reduced epithelial-mesenchymal transition. Moreover, the c-Met oncogene, which is upregulated in HCC tissues, was negatively associated with the expression of miR-206. Notably, it was shown that miR-206 may exert its antitumor effect through suppressing c-Met/Akt/mTOR signaling. Low expression of miR-206 was shown to be regulated by lncRNA MALAT1 in HCC. Collectively, this study presented evidence that miR-206 was controlled by lncRNA MALAT1 and partially suppressed the proliferation and invasion of HCC through the c-Met/Akt/mTOR signaling pathway. According to these results, understanding MALAT1/miR-206-dependent regulation may lead to potential approaches for diagnosis and prospective treatment of HCC.

Biological impact and therapeutic perspective of targeting PI3K/Akt signaling in hepatocellular carcinoma: Promises and Challenges

Cancer progression results from activation of various signaling networks. Among these, PI3K/Akt signaling contributes to proliferation, invasion, and inhibition of apoptosis. Hepatocellular carcinoma (HCC) is a primary liver cancer with high incidence rate, especially in regions with high prevalence of viral hepatitis infection. Autoimmune disorders, diabetes mellitus, obesity, alcohol consumption, and inflammation can also lead to initiation and development of HCC. The treatment of HCC depends on the identification of oncogenic factors that lead tumor cells to develop resistance to therapy. The present review article focuses on the role of PI3K/Akt signaling in HCC progression. Activation of PI3K/Akt signaling promotes glucose uptake, favors glycolysis and increases tumor cell proliferation. It inhibits both apoptosis and autophagy while promoting HCC cell survival. PI3K/Akt stimulates epithelial-to-mesenchymal transition (EMT) and increases matrix-metalloproteinase (MMP) expression during HCC metastasis. In addition to increasing colony formation capacity and facilitating the spread of tumor cells, PI3K/Akt signaling stimulates angiogenesis. Therefore, silencing PI3K/Akt signaling prevents aggressive HCC cell behavior. Activation of PI3K/Akt signaling can confer drug resistance, particularly to sorafenib, and decreases the radio-sensitivity of HCC cells. Anti-cancer agents, like phytochemicals and small molecules can suppress PI3K/Akt signaling by limiting HCC progression. Being upregulated in tumor tissues and clinical samples, PI3K/Akt can also be used as a biomarker to predict patients' response to therapy.

Potential role of circulating miR-21 in the diagnosis of hepatocellular carcinoma: a systematic review and meta-analysis

OBJECTIVE

Identify original articles that analyzed the diagnostic value of miR-21 in hepatocellular carcinoma without language restriction or publication date.

METHODOLOGY

We performed structured searches on PubMed, Web of Science, VHL, and EMBASE. The Standard Quality Assessment Criteria for Evaluating Primary Research Papers from a Variety of Fields was used to assess the quality of each study. Random effect models were used to study heterogeneity, evaluated based on the Higgins I2 statistic.

RESULTS

12 articles were evaluated and contained raw data from 1,329 individuals, of which 617 had HCC, 473 were healthy, and 239 had Chronic liver disease. The combined sensitivity and combined specificity of miR-21 for diagnosing HCC were, respectively, 0.83(95% CI:0.78-0.89) and 0.85(95% CI:0.80-0.90). The sensitivity and specificity, in that order, by type of control were 0.81 (95% CI: 0.71-0.91) and 0.88 (95% CI: 0.82-0.93) for CLDs and 0.86(95% CI: 0.81-0.91) and 0.83(95% CI:0.74-0.91) for Healthy controls.

CONCLUSION

miR-21 has a moderate overall performance in diagnosing HCC and may serve as a potential non-invasive marker for this early-stage disease. Thus, it may contribute to complementing the results of alpha-fetoprotein in the diagnosis and help to detect HCC at an earlier stage, increasing the survival chances of these patients.

MiR-125b-5p is targeted by curcumin to regulate the cellular antioxidant capacity

As a natural polyphenolic food supplement and the principal curcuminoid in turmeric, curcumin shows antioxidant, anti-inflammatory, and antitumor activities. However, its specific functional mechanism remains unclear. Our preliminary study indicated that miR-125b-5p was downregulated by a curcumin extract. This study aimed to determine whether miR-125b-5p is involved in the antioxidant regulation of curcumin. The results showed that miR-125b-5p overexpression had a pro-oxidant effect by reducing the cellular antioxidant capacity, as well as decreasing the activities of catalase (CAT) and superoxide dismutase (SOD) in the normal liver cell line LO2. However, miR-125b-5p repression significantly increased the cellular antioxidant capacity and enhanced the activities of CAT and SOD. Further investigation demonstrated that the cellular antioxidant capacity induced by curcumin extract was inhibited by miR-125b-5p overexpression. Thus, curcumin may exhibit antioxidant effects by repressing miR-125b-5p expression, which provides new insights into the molecular antioxidant mechanism of curcumin and other functional food components.

The Emerging Role of EVA1A in Different Types of Cancers

Eva-1 homolog A (EVA1A), also known as transmembrane protein 166 (TMEM166) and regulator of programmed cell death, is an endoplasmic reticulum associated protein, which can play an important role in many diseases, including a variety of cancers, by regulating autophagy/apoptosis. However, the related mechanism, especially the role of EVA1A in cancers, has not been fully understood. In this review, we summarize the recent studies on the role of EVA1A in different types of cancers, including breast cancer, papillary thyroid cancer, non-small cell lung cancer, hepatocellular carcinoma, glioblastoma and pancreatic cancer, and analyze the relevant mechanisms to provide a theoretical basis for future related research.