Deregulated expression of the Per1 and Per2 in human gliomas

• Published in: Canadian journal of neurological sciences Vol. 37; no. 3; p. 365
• Main Authors: Xia, He-chun, Niu, Zhan-feng, Ma, Hui, Cao, Shuan-zhu, Hao, Shao-cai, Liu, Zhong-tao, Wang, Fan
• Format: Journal Article
• Language: English
• Published: England 01.05.2010
• Subjects: Adolescent; Adult; Aged; Brain Neoplasms - genetics; Brain Neoplasms - physiopathology; Child; Female; Gene Expression Regulation, Neoplastic - physiology; Glioma - genetics; Glioma - physiopathology; Humans; Male; Middle Aged; Period Circadian Proteins - genetics; Period Circadian Proteins - metabolism; Retrospective Studies; RNA, Messenger - metabolism; Young Adult
• ISSN: 0317-1671; 2057-0155
• DOI: 10.1017/s031716710001026x

Growing evidence shows that the deregulation of the circadian clock plays an important role in the development of malignant tumors, including gliomas. However, the molecular mechanisms of genes controlling circadian rhythm in glioma cells have not been explored. Using reverse transcription polymerase chain reaction and immunohistochemistry techniques, we examined the expression of two important clock genes, Per1 and Per2, in 33 gliomas. In this study, out of 33 gliomas, 28 were Per1-positive, and 23 were Per2-positive. The expression levels of Per1 and Per2 in glioma cells were significantly different from the surrounding non-glioma cells (P<0.01). The difference in the expression rate of Per1 and Per2 in high-grade (grade III and IV) and low-grade (grade 1 and II) gliomas was insignificant (P>0.05). While there was no difference in the intensity of immunoactivity for Per2 between high-grade gliomas and low-grade gliomas (r=-0.330, P=0.061), the expression level of Per1 in high-grade gliomas was significantly lower than that in low-grade gliomas(r=-0.433, P=0.012). In this study, we found that the expression of Per1 and Per2 in glioma cells was much lower than in the surrounding non-glioma cells. Therefore, we suggest that disturbances in Per1 and Per2 expression may result in the disruption of the control of normal circadian rhythm, thus benefiting the survival of glioma cells. Differential expression of circadian clock genes in glioma and non-glioma cells may provide a molecular basis for the chemotherapy of gliomas.