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.

piRNA: A promising biomarker in early detection of gastrointestinal cancer.

Gastrointestinal (GI) cancer has become the primary concern of today's society due to its aggressive nature and poor prognosis. PIWI-interacting RNAs (piRNAs), a subgroup of non-coding RNAs, are mainly expressed in the germline and have emerged as a critical regulator in gene expression and the epigenetic silencing of DNA transposable elements by interacting with PIWI proteins. piRNAs' dysregulations were reported to promote or suppress the initiation and development of different malignancies, especially gastrointestinal cancers. Recently, several studies suggested the use of piRNAs as potential cancer biomarkers associated with the progression and chemoresistance of GI cancer. Hence, this review article aims to focus on the role of piRNAs in GI cancer progression, metastasis, and their molecular mechanisms as therapeutic markers for GI cancer patients.

The effective function of circular RNA in colorectal cancer.

Colorectal cancer (CRC) is the 3rd most common type of cancer worldwide. Late detection plays role in one-third of annual mortality due to CRC. Therefore, it is essential to find a precise and optimal diagnostic and prognostic biomarker for the identification and treatment of colorectal tumorigenesis. Covalently closed, circular RNAs (circRNAs) are a class of non-coding RNAs, which can have the same function as microRNA (miRNA) sponges, as regulators of splicing and transcription, and as interactors with RNA-binding proteins (RBPs). Therefore, circRNAs have been investigated as specific targets for diagnostic and prognostic detection of CRC. These non-coding RNAs are also linked to metastasis, proliferation, differentiation, migration, angiogenesis, apoptosis, and drug resistance, illustrating the importance of understanding their involvement in the molecular mechanisms of development and progression of CRC. In this review, we present a detailed summary of recent findings relating to the dysregulation of circRNAs and their potential role in CRC.

Circular RNA hsa_circ_0005046 and hsa_circ_0001791 May Become Diagnostic Biomarkers for Breast Cancer Early Detection.

Breast cancer (BC) is one of the most common lethal diseases in women worldwide. Recent evidence has shown that covalently closed Circular RNA (circRNA) deregulation is observed in different human malignancies and cancers. Lately, circRNAs are being considered as a new diagnostic biomarker; however, the mechanism and the correlation of action between circRNAs and BC are still unclear. In the present study, we try to investigate the expression level of hsa_circ_0005046 and hsa_circ_0001791 in BC. By using quantitative real-time polymerase chain reaction (qRT-PCR), expression profiles of candidate circRNAs were detected in 60 BC tissue and paired adjacent normal tissues. Furthermore, the clinicopathological relation and diagnostic value were estimated. Our results showed the higher expression levels of hsa_circ_0005046 and hsa_circ_0001791 in BC tissues compared to paired adjacent normal tissues with P value (P < 0.0001) for both circRNAs, and the area under the receiver operating characteristic (ROC) curve was 0.857 and 1.0, respectively; in addition, a total 10 miRNAs that can be targeted by each candidate circRNAs was predicted base on bioinformatics databases. Taken together, for the first time, the results of our study presented high expression levels of hsa_circ_0005046 and hsa_circ_00017916 in BC; although there was no direct correlation between the high expression level of both circRNAs with clinic pathological factors, except hsa_circ_0001791 association with estrogen receptors (ER), high ROC curve in expressed samples indicated that both circRNAs could be used as a new diagnostic biomarker for BC. Moreover, miRNAs selection tools predicted that miR-215 and mir-383-5p which have a tumor suppressor role in BC can be targeted by our candidate circRNAs to affect the PI3K/AKT pathway; in conclusion, further studies are required to validate the oncogene role of our candidate circRNAs through the PI3k pathway.

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.