The Experimental Study Of Iodine-125Seeds With The Human Colon Cancer P16Gene Methylation Effects

Objective:We established human colon cancer cells (HCT-8) transplanted into nude mice model. From iodine-125seeds radiation therapy, to research ocolon cancer p16gene methylation abnormalities, we explor the possiblly molecular mechanisms of treatment colon cancer to use iodine-125seeds.Methods:The BALB/c-nu/nu nude mice are randomly divided into three groups (n=25).One is blank controrl group, which to be implanted empty seeds, without iodine-125radioelement(OMBq); The second is experiment group, which to be implanted iodine-125seeds (14.8MBq). The third group is a control group,which is nothing implantation. The experimental group was implanted dose of1251seeds0.6mCi (1mCi=37MBq when implanted1251seeds28days, Put to death all nude mice and obtain tumor specimens. And using an electronic balance to weight the tumor,stored samples at-80℃C refrigerator.Through every3days to measure the size of the tumor,And get the tumor weight after put to death all nude. Compare the inhibition rate of the experimental group and control group and blank control group. Tumor specimens extracted DNA, sodium bisulfite modification of genomic DNA, use the MSP ways to detected influences about iodine-125seeds about colon cancer p16geneResults:1. Experimental group on the inhibitory rate of the blank control group was43%, experimental group on the inhibitory rate of the control group was38%.2. Iodine-125seeds inter-organizational implantation of colon cancer, The experimental group P16gene methylation rate (56%), methylation was significantly lower than the control group (84%) and the control group (80%). Experimental group compared with the control group and blank control group, the difference was statistically significant (P<0.05). Conclusions:1. Iodine-125seeds can inhibited colon cancer tumor growth significantly.2. This experiment is cinfirm that iodine-125seeds radiation treatment human colon cancer have evidence effective.after iodine-125seeds radiation therapy reduced the methylation rate of tumor p16gene, iodine-125seeds can significantly decreased the p16gene methylation colon cancer.3. p16gene methylation decrease lead suppression tumor may be one of the molecular mechanisms.