Evaluation of Radiotherapy on miR-374 Gene Expression in Colorectal Cancer Patient Blood Samples.

Background: Current cancer treatments include surgery, radiotherapy, chemotherapy, and immunotherapy. Despite these treatments, a main issue in cancer treatment is early detection. microRNAs (miRNAs) can be used as markers to diagnose and treat cancers. This study investigated the effect of radiotherapy on miR-374 expression, and APC and GSK-3ß, two of its target genes, in the WNT pathway, in peripheral blood samples from radiotherapy-treated colorectal cancer (CRC) patients. Methods: Peripheral blood was collected from 25 patients before and after radiotherapy. RNA was extracted from the blood and cDNA synthesized. miR-374, APC, and GSK-3ß expression was determined by real-time polymerase chain reaction (RT-PCR) and the amplicons were sequenced. Finally, the data were statistically evaluated. Results: Quantitative RT-PCR revealed significant down-regulation of miR-374 (0.63-fold) and up-regulation of APC (1.12-fold) and GSK-3ß (1.22-fold) in CRC patients after five weeks of radiotherapy. Sequencing of PCR-produced amplicons confirmed the conservation of mature and precursor sequences encoding miR-374. miR-374 expression changed with time after radiotherapy treatment and related tumor grading. Increased age and tumor grade positively correlated with decreased miR-374 expression. Conclusion: miR-374 expression, and that of its two target genes, APC and GSK-3ß, changed after radiotherapy. These genes can likely be used as diagnostic radiotherapy markers in CRC.

trfA1 Gene in clinical isolates of Mycobacterium tuberculosis.

OBJECTIVE/BACKGROUND: The incidence of resistant strains of Mycobacterium tuberculosis (MTB), including multi-drug resistant, extensively drug resistant, or totally drug resistant, is one of the major problems of health policies worldwide. The accumulation of mutations causes multi-drug resistant strains. Mycobacterium abscessus has a plasmid called pMab2401 containing the trfA1 gene in its integron part. The aim of the present study was to investigate the possible existence of the trfA1 gene in clinical strains of MTB for the first time. METHODS: Bioinformatics analysis in GenBank revealed an absence of any integrons or internal components in MTB. Several specific primers for different genes and the trfA1 gene of M. abscessus were used in a touch-down (60-52) amplification program and followed by loading on gel electrophoresis. Products were extracted and were sequenced. Sequencing results were analyzed carefully and compared with those in the databank. RESULTS: Bands of 500bp were resulted with pair primers in an amplification reaction by clinical MTB that has 94% identity with a fragment in most plasmids and phages M13. It should be noted that such an independent replication system-like structure has not been reported to date in MTB strains. CONCLUSION: The trfA1 gene is depends on the replication process. It is necessary to investigate other probable new areas that may be of concern with drug resistance in clinical isolates of MTB.