Progress of Epigenetic Study on Nasopharyngeal Carcinoma / 生物化学与生物物理进展

Epigenetics is the important component of functional genomics. It can be defined as the study of the interplay between environment and genetics, and the study of the heritable change that is not strictly dependent on DNA sequence. Nasopharyngeal carcinoma (NPC) is the common malignant tumor in south China. As a polygenetic inheritance tumor, NPC has the characteristic of obvious tendency of familial aggregation, possesses genomic instability, and is vulnerable to physical, chemical and biological carcinogenic factors. This specific etiological system of NPC refers that it is one of the best model for studying cancer epigenetics. The main point of this review focuses on the progress of studying on the effects of DNA methylation, histone modification, chromatin remodeling and non-coding RNA regulation on the pathologenesis of NPC, and suggests future directions to thoroughly explore the epigenetic pathologenesis of NPC. Moreover, it will open a new prerequisite foundation for finding the epigenetic molecular marks for screening the high-risk susceptibility population, early diagnosis, treatment and prognostic indentification of NPC.

Expression of vascular basement membrane-derived multifunctional peptide in Pichia pastoris and identification of its bioactivity / 中国肿瘤生物治疗杂志

Objective: To express vascular basement membrane-derived multiple peptide (VBMDMP) in Pichia pastoris and to identify its bioactivity. Methods: PCR technique was used to obtain the target fragment GST-VBMDMP, which was then cloned into pPIC9K vector. The resultant vector pPIC9K-GST-VBMDMP was transfected into Pichia pastoris cells with spheroplast and the positive recons was identified. The His + Muts transformant was shake-cultured in MGY at 30 ℃. The culture supernatant (1 ml) was collected for preservation at-70 ℃ every 24 hours while maintaining the concentration of methanol at 0.5% in the culture medium. SDS-PAGE analysis was used to detect the protein expression after 8 days and then animal and cell experiments were performed with GST-VBMDMP. Results: SDS-PAGE analysis found that protein express increased during 1-7 days and decreased after 8 days in MGY medium; GST-VBMDMP fused protein was obtained by Glutathione Sepharose 4B and it inhibited the artery endothelial cell tube structure formation in C57BL/6 mouse; GST-VBMDMP( 2, 6, 10 mg/kg)also significantly inhibited the primary cancer Lewis mouse (tumor inhibitor rates being 96.6%, 82.1%, and 61.2%, respectively)and metastatic lung tumors(tumor inhibitor rates being 96.8 %, 87.9 %, and 75.3%, respectively)(P