Mina Lashkarboloki; Amin Jahanbakhshi; Seyed Javad Mowla; Bahram Mohammad Soltani
Abstract
Cancer is one of the most challenging diseases in the world. It is widely accepted that knowing the molecular aspects of diseases, including cancers, helps to develop methods for their therapy and diagnosis. Long non-coding RNAs (lncRANs) are a novel category of regulatory genes known to be involved ...
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Cancer is one of the most challenging diseases in the world. It is widely accepted that knowing the molecular aspects of diseases, including cancers, helps to develop methods for their therapy and diagnosis. Long non-coding RNAs (lncRANs) are a novel category of regulatory genes known to be involved in cancer incidence. The expression of these genes is said to be suitable of using in prognosis, diagnosis, targeted therapy, etc. The RT-qPCR method that is widely used for analyzing the gene expression requires the application of appropriate reference genes as the internal control. The expression status of a proper housekeeping reference gene is not supposed to change under experimental circumstances. This study aimed to find a suitable reference gene in the U87 cells after overexpression of a gene of interest. To this aim, the expression status of four common reference genes (ACTB, β2M, GAPDH, and HPRT1) was examined in the transfected U87 cells. The U87 cells were transfected with a vector overexpressing YWHAE-lncRNA and an empty vector (mock). After total RNA extraction and cDNA synthesis, RT-qPCR was applied using the aforementioned internal control genes. Data were analyzed, and their graphs were plotted in GraphPad Prism 8.2 software. Β2M showed the most change; accordingly, GAPDH and HPRT1 expression levels were changed about 5 and 4 times, respectively. Of the candidate genes, only the ACTB gene had a consistent expression level in two different modes of transfection, and therefore, it is suggested as an appropriate reference gene for the study of gene expression in the transfected U87 cell line. It is remained to be tested if β2M, GAPDH, and HPRT1 common internal controls are specifically affected by YWHAE-lncRNA overexpression or other lncRNAs may affect their expression as well.
Sara Soltanian; Mahboubeh Sheikhbahaei
Abstract
Real-time quantitative PCR (qRT-PCR) is often used as an effective experimental method for analyzing gene expression. In this method, normalization of target gene expression levels must be performed using housekeeping genes (HKGs). HKGs are used to compensate for difference between ...
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Real-time quantitative PCR (qRT-PCR) is often used as an effective experimental method for analyzing gene expression. In this method, normalization of target gene expression levels must be performed using housekeeping genes (HKGs). HKGs are used to compensate for difference between samples due to diverse quality and quality of RNAs and different reverse transcription yield. For an ideal reference gene, constant expression levels across different samples of one experiment is necessary. In the current study, expression stability of four candidate references genes including Beta actin (ACTB), glyceraldeyde-3-phosphate dehydrogenase (GAPDH), hypoxanthine guanine phosphoribosyl transferase (HPRT1) and Beta-2-Microglobulin (β2M) following retinoic acid (RA) treatment in embryonal carcinoma NCCIT cells were evaluated.NCCIT cells were exposed to RA (10 µM) for 14 days to induce differentiation. RT-qPCR for candidate references genes was performed and normalization between untreated and RA-treated cells was performed using identical sample input amounts. Expression of OCT4, SOX2, NANOG during RA-induced differentiation was assessed by quantitative real-time PCR. RT-qPCR results indicated significant difference in expression level of GAPDH between untreated (Ct mean: 19.36667± 0.28) and RA-treated (Ct mean: 28.94± 0.18) NCCIT cells. However, transcriptional level of ACTB, HPRT and β2M remained unchanged after RA treatment. qRT-PCR analysis using ACTB, HPRT and β2M showed treatment of NCCIT cells with RA lead to significant down regulation of OCT4 (79%), NANOG (71%) and SOX2 (96%) transcript. ACTB, HPRT and β2M were recognized as valid reference genes for analysis of gene expression during RA-induced differentiation of NCCIT cells, while GAPDH was not suitable.
