Background and purpose: Since there is no unified and effective treatment for patients with advanced colorectal cancer currently

exploring the factors that affect the occurrence and development of colorectal cancer is beneficial to elderly patients. The effect of hypoxia-inducible factor-1α (HIF-1α) on the proliferation of human colorectal cancer cells was investigated by nude mice xenograft experiments. Methods: The expression of HIF-1α was down-regulated by RNA interference

and the cell transfection rate was verified by Western blot and reverse transcription polymerase chain reaction (RT-PCR). Apoptosis in blank

experimental and negative control cells was detected by Annexin Ⅴ-fluorescein isothiocyanate (FITC)/propidium iodide (PI) flow cytometry. The cells from the blank control

the experimental and the negative control groups were separately injected into the nude mice to perform tumorigenic experiments. Then the volume and weight of each group of transplanted tumors were measured

and the effect of inhibiting HIF-1α expression on the proliferation of human colorectal cancer cells was evaluated. Results: After transfection

the expression of HIF-1α in the si-HIF-1α group was decreased. Compared with the blank control group

the apoptotic rate of the experimental group was significantly increased (P0.05)

and the volume and weight of the tumor in the experimental group were significantly decreased (P0.05). However

there was no significant difference in tumor volume and weight changes between the negative control group and the nude control group (P0.05). Conclusion: Down-regulation of the expression level of HIF-1α can inhibit the proliferation and tumorigenic ability of human colorectal cancer cells.