Circulating Let-7 Family Members as Non-Invasive Biomarkers for Predicting Hepatocellular Carcinoma Risk after Antiviral Treatment among Chronic Hepatitis C Patients

Let-7a-3p overexpression increases chemosensitivity to carmustine and synergistically promotes autophagy and suppresses cell survival in U87MG glioblastoma cancer cells

In terms of primary brain tumors, glioblastoma is one of the most aggressive and common brain tumors. The high resistance of glioblastoma to chemotherapy has made it vital to find alternative treatments and biological mechanisms to reduce the survival of cancer cells. Given that, the objective of the present research was to explore the potential of let-7a-3p when used in combination with carmustine in human glioblastoma cancer cells. Based on previous studies, the expression of let-7a is downregulated in the U87MG cell line. Let-7a-3p transfected into U87MG glioblastoma cells. Cell viability of the cells was assessed by MTT assay. The apoptotic induction in U87MG cancerous cells was determined through the utilization of DAPI and Annexin V/PI staining techniques. Moreover, the induction of autophagy and cell cycle arrest was evaluated by flow cytometry. Furthermore, cell migration was evaluated by the wound healing assay while colony formation assay was conducted to evaluate colony formation. Also, the expression of the relevant genes was evaluated using qRT-PCR. Transfection of let-7a-3p mimic in U87MG cells increased the expression of the miRNA and also increased the sensitivity of U87MG cells to carmustine. Let-7a-3p and carmustine induced sub-G1 and S phase cell cycle arrest, respectively. Combination treatment of let-7a-3p and carmustine synergistically increased arrested cells and induced apoptosis through regulating involved genes including P53, caspase-3, Bcl-2, and Bax. Combined treatment with let-7a-3p and carmustine also induced autophagy and increased the expression of the ATG5 and Beclin 1 (ATG6). Furthermore, let-7a-3p combined with carmustine inhibited cell migration via decreasing the expression of MMP-2. Moreover, the combination therapy decreased the ability of U87MG to form colonies through downregulating CD-44. In conclusion, our work suggests that combining let-7a-3p replacement therapy with carmustine treatment could be considered a promising strategy in treatment and can increase efficiency of glioblastoma chemotherapy.

Dual mechanism of Let-7i in tumor progression

Let-7i regulates tumors primarily by binding to the 3' untranslated region (3' UTR) of mRNA, which indirectly regulates post-transcriptional gene expression. Let-7i also has an epigenetic function via modulating DNA methylation to directly regulate gene expression. Let-7i performs a dual role by inducing both the promotion and inhibition of various malignancies, depending on its target. The mechanism of Let-7i action involves cancer cell proliferation, migration, invasion, apoptosis, epithelial-mesenchymal transition, EV transmission, angiogenesis, autophagy, and drug resistance sensitization. Let-7i is closely related to cancer, and hence, is a potential biomarker for the diagnosis and prognosis of various cancers. Therapeutically, it can be used to promote an anti-cancer immune response by modifying exosomes, thus exerting a tumor-suppressive effect.

Research progress of circulating non-coding RNA in diagnosis and treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a highly malignant tumor that carries a significant risk of morbidity and mortality. This type of cancer is prevalent in Asia due to the widespread presence of risk factors. Unfortunately, HCC often goes undetected until it has reached an advanced stage, making early detection and treatment critical for better outcomes. Alpha-fetoprotein (AFP) is commonly used in clinical practice for diagnosing HCC, but its sensitivity and specificity are limited. While surgery and liver transplantation are the main radical treatments, drug therapy and local interventions are better options for patients with advanced HCC. Accurately assessing treatment efficacy and adjusting plans in a timely manner can significantly improve the prognosis of HCC. Non-coding RNA gene transcription products cannot participate in protein production, but they can regulate gene expression and protein function through the regulation of transcription and translation processes. These non-coding RNAs have been found to be associated with tumor development in various types of tumors. Noncoding RNA released by tumor or blood cells can circulate in the blood and serve as a biomarker for diagnosis, prognosis, and efficacy assessment. This article explores the unique role of circulating noncoding RNA in HCC from various perspectives.

The Application of Liquid Biopsy Techniques in High-Risk Population for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors of the digestive system and has a 5-year overall survival rate of 14.1%. Many HCC patients are diagnosed at an advanced stage, and thus early screening is essential for reducing the mortality of HCC. In addition to commonly used detection indicators such as serum alpha-fetoprotein (AFP), lens culinaris agglutinin-reactive fraction of alpha-fetoprotein (AFP-L3) and abnormal prothrombin (protein induced by vitamin K absence II, PIVKA-II), liquid biopsy techniques have been demonstrated to have diagnostic value in HCC detection. Compared with invasive procedures, liquid biopsy can detect circulatory metabolites of malignant neoplasms. Liquid biopsy techniques can detect circulating tumor cells, circulating tumor DNA, circulating RNA and exosomes and have been used in the early screening, diagnosis and prognostic evaluation of HCC. This paper reviews the molecular biological characteristics and application of different liquid biopsy techniques, and aim to highlight promising biomarkers that may be feasible options for early-stage HCC evaluation to improve early screening in populations at high risk for HCC.