Effect and mechanisms of curcumin on the radiosensitivity of human ACHN renal cell carcinoma xenografts / 西安交通大学学报(医学版)

ABSTRACT

Objective: To investigate the effect and mechanisms of curcumin on the radiosensitivity of human ACHN renal cell carcinoma xenografts. Methods: ACHN cells were xenografted into nude mice subcutaneously. Preliminary experiments were conducted to observe the tolerance of curcumin and radiation, and the appropriate dose of curcumin for subsequent experiments was selected. The nude mice were divided into different groups randomly. Tumor growth was monitored following intervention. The radiosensitization ratio (E/O) of curcumin and tumor inhibition rate were calculated. Flow cytometry was employed to detect apoptosis of xenografts cells in different groups. The expression of NF-κB signaling related proteins in ACHN cells and xenografts was detected by Western blot. Results: The method of tumor cell suspensions inoculation manifested a good tumor-take rate of 85.7%. Curcumin (25 mg/kg) could enhance the radiosensitivity of ACHN transplanted human renal carcinoma in nude mice. The E/O ratio was 1.64 (>1.4). Compared with that in the radiation group, the apoptosis rate in curcumin + radiation group was markedly increased (P<0.05). The expression levels of NF-κB, DNA-PKcs and downstream regulatory proteins, including VEGF, COX2 and Bcl-2, were obviously suppressed by curcumin in combination with IR treatment (all P<0.05 vs. IR group). Conclusion: Curcumin enhanced radiosensitivity of ACHN RCC xenografts by inhibiting DNA damage repair, inducing apoptosis and suppressing IR-induced NF-κB signaling.