NPAS2 gene expression in gastric cancer

The circadian clock refers to the inherent biological rhythm of an organism, which, is accurately regulated by numerous clock genes. It has been reported that the abnormal expression of clock genes is ubiquitous in common malignant tumors. Circadian clock regulation in mammals is controlled by feedback loops of a set of circadian genes. One of these circadian genes, NPAS2, encodes for a member of the bHLH-PAS class of transcription factors and is expressed in the forebrain and in some peripheral organs. NPAS2, an essential component of the feedback loop, dimerizes with ARNTL, another core circadian protein, and binds to DNA sequences to activate gene transcription. NPAS2/ ARNTL heterodimer controls the transcription of two other circadian genes PER and CRY, which are required for maintaining biologic rhythms in many organisms. It has been shown that the NPAS2 is involved in cell proliferation, DNA damage repair and malignant transformation. The objective of this study was to study the relative expression level of NPAS2 in gastric cancer compare with normal gastric mucosa. RNA was extracted from 30 resected tumor and 30 normal gastric specimens. The expression levels of NPAS2 mRNA were determined by qRT-PCR. The results showed that there was a significant difference in the expression of NPAS2 gene between patient and control groups (P<0.05). In conclusion, our findings in this research suggest that the altered gene expression in NPAS2 gene is related to gastric tumor formation. However, further studies with a larger sample size are required to verify these results.

کلیدواژه ها:

Gastric cancer ، NPAS2 ، Circadian rhythm