The Experimental Study Of Iodine-125 Seeds Brachytherapy Influence HIF-1α Expression And Apoptosis Of Human Colorectal Cancer (HCT-116)

Ojective:The study is desired to investigate the effect of the iodine-125 seeds brachytherapy on poorly differentiated colorectal cancer. we explor the mechanism of this therapy. Make clear the efficiency of this therapy on poorly differentiated colorectal cancer Methods:The BALB/c-nu/nu nude mice are randomly divided into two groups (n=24).One is controrl group, which to be implanted empty seeds, without iodine-125 radioelement(OMBq); The other is experiment group, which to be implanted iodine-125 seeds (14.8MBq). Then we observed the condition of tumor growth after implanting iodine-125. In 7th,14th,21th,28th day after implantation, we killed 6 nude mice per group. And observe the changes of the tumor cells ultrastructural by TEM, detect the change of PCNA by immunohistochemical SP method, and detect the mRNA levels of HIF-la at different time-point by RT-PCR. Results:The inhibitary rate of transplanted tumors in experiment group was 47.12%. we observe the early-mid-late period cell apoptosis in the experiment group by TEM, few cells apoptosis were found in the control group. The expressions of HIF-1αmRNA in tumor tissue are lower than that of in control group.There were significantly difference compared with the controls(P＜0.05). Conclusions:l.This study verifies the efficiency of the iodine-125 seeds brachytherapy in inhibiting the growth of colorectal cancer cell. Iodine-125 interstitial brachytherapy also can inhibite vascularization in colorectal cancer.2. It inhibite the proliferation and induce the apoptosis of HCT-116 cell.