MicroRNA-26b Reduces Cell Viability by Inhibition of Nicotinamide Phosphoribosyltransferase in Breast Cancer Cells.

Breast cancer (BC) is one of the most common causes of cancer in women worldwide and it is found to be associated with an increased level of Nicotinamide phosphoribosyltransferase (NAMPT), which plays an important role in nicotinamide adenine dinucleotide (NAD) pathway, both in blood and tumor tissues. This enzyme is also essential for the growth and survival of cancer cells. The short noncoding RNA microRNAs miR-26b is an important gene regulator and a tumor suppressor in different human cancers, including BC. In this study, bioinformatics analysis was evaluated to find the miRNAs targeting NAMPT 3' untranslated regions (3' UTRs), which was confirmed by luciferase assay. Next, we evaluate NAMPT and microRNA-26b (miR-26b) expression by using polymerase chain reaction (PCR) in BC. miR-26b effect on cell viability was also evaluated by Cell Counting Kit-8 (CCK-8). Following transfection with miR-613 mimic, the expression of miR-613 was elevated in the BC cells leading to inhibition of NAMPT expression at both mRNA and protein level as measured by real-time PCR and western blotting. Our result identified a significant tumor suppressor role of miR-26b on NAMPT, NAD concentration, and cell viability in BC. Overall, based on our finding, miR-26b mimic transfection could elevate miR-26b levels in BC cells via downregulating the NAMPT expression, NAD expression levels, and cell growth, whereas miR-26b inhibitor had the opposite function. In conclusion, miR-26b can become a promising target for BC treatment through targeting NAMPT and inhibiting the NAD production.

The inhibitory role of stigmasterol on tumor growth by inducing apoptosis in Balb/c mouse with spontaneous breast tumor (SMMT).

BACKGROUND: Breast cancer is one of the most common types of cancer in women worldwide. Anti-apoptotic activity of cancer cells is considered the main reason for drug resistance in BC which reduces the 5-year survival rate of patients and is still considered the main obstacle for cancer therapy. Stigmasterol (SS) is natural phytosterols compound in the plant which has been proved to play an important role to lower cholesterol and inducing anti-inflammatory, and anticancer properties. METHODS: In this, study, we aimed to evaluate the effect of SS on the expression of anti-apoptotic genes (Bcl-2 and BCL-XL), and also evaluate its effects on cell apoptosis and cell viability using MCF-7 cell line as well as evaluating its effect on tumor growth of spontaneous breast tumor (SMMT) in vivo. RESULT: SS significantly decreased the expression of Bcl-2 and BCL-XL genes (*P < 0.05), induced apoptosis, and reduced cell proliferation in MCF-7 cell lines. Our in vivo study also indicated that SS could inhibit tumor size after treatment with (0, 10, 20 µM) compared to the normal control. CONCLUSION: SS can be suggested as a potential agent in BC cancer treatment or as an adjuvant based on its ability to decrease the expression of Bcl-2 and BCL-XL genes and induce apoptosis.

Circular RNA circ_0051620 sponges miR-338-3p and regulates ADAM17 to promote the gastric cancer progression.

BACKGROUND: Gastric cancer (GC) is the fifth most common threatening cancer-related death globally. Recent studies indicate that circRNAs play a critical role in various biological and pathogenesis processes, including proliferation, apoptosis, and invasion of GC through sponging different miRNAs. However, the in-depth investigations of circRNAs in the progression of GC remains unclear, therefore in the current study, we aimed to investigate the mechanism behind the circular RNA circ_0051620 in the progression of GC through spooning the miR-338-3p and ADAM17. METHODS: At first, circRNA microarray was used to identify the expression profiles of circRNA in GC tissues. Further, qRT-PCR was performed to detect genes expression. Then, the clinical significance of circ_0051620 was evaluated. Afterward, bioinformatical database, dual-luciferase reporter assays were used to determine the regulatory networks of circ_0051620 and miR-338-3p in GC cells respectively. The Transwell experiments were used to explore the effects of circ_0051620, miR-338-3p, ADAM17 on the migration and invasion of GC cells. RESULTS: qRT-PCR results indicated that circ_0051620 in GC was over-expressed in tumoral tissues and cell lines compared to the normal controls. Moreover, miR-338-3p was confirmed to be the target of circ_0051620. Overall overexpression of miR-338-3p inhibited the cell migration, invasion through inhibiting ADAM17 in GC cells. CONCLUSION: The overexpression of circ_0051620 is found to be associated with progress and poor prognosis of GC, promoting the development and metastasis via sponging miR-338-3p and decoying ADAM17.

Long Non-coding RNA snaR Promotes Proliferation in EGFR Wild Type Non-Small Cell Lung Cancer Cells.

Lung cancer is the second most common cancer and has high morbidity and mortality worldwide with non-small cell lung cancer (NSCLC) accounting for 85% of the cases. Over-expression of epidermal growth factor receptor (EGFR) has been clarified in different cancers, and has been shown to have a crucial role in tumor progression. In this study, we evaluated long non-coding RNA small NF90-associated RNA (snaR) expression in different EGFR-statue cell lines. Knockdown experiments were conducted to analyze snaR expression in selected cell lines. MTT and transwell assays were respectively employed to evaluate the proliferative and invasive abilities of NSCLC cells. The expression of snaR was remarkably up-regulated in SPC-A1 and A549 wild-type EGFR cell lines. Down regulation of snaR with small interfering RNA significantly inhibited cell invasion as well as proliferation of SPC-A1 and A549 cells. Our results indicate that snaR may be a potential therapeutic biomarker for NSCLC.