塞来昔布对宫颈癌HeLa细胞的放射增敏作用观察及机制探讨

目的观察环氧合酶2（COX-2）抑制剂塞来昔布对宫颈癌HeLa细胞的放射增敏作用，并探讨其机制。方法将对数生长期的HeLa细胞分为3组，阴性对照组单纯培养液培养，单纯放射组采用6MV的x线照射治疗，放射加药组先用20、40umol／L塞来昔布作用72h，再行x线照射。采用克隆形成实验测算细胞放射敏感性参数平均致死剂量（Do）、准域剂量（Dq）、2Gy照射存活分数（SF2）及放射增敏比（SERDo），采用免疫细胞化学法检测HeLa细胞中的COX-2、VEGF—C。结果放射加药组Do、Dq和SF2值小于单纯放射组（P均〈0．05），其SERDo由2．01±0．06增至2．41±0．08；与阴性对照组、单纯放射组比较，放射加药组HeLa细胞的COX-2、VEGF—C表达显著降低（P均〈0．05）。结论塞来昔布能增强宫颈癌HeLa细胞的放射敏感性，可能与下调宫颈癌细胞的COX-2、VEGF—C表达有关。

Effect and mechanism of celecoxib on radiosensitivity enhancement in cervical cancer HeLa cells

Objective To observe the effect of celecoxib on radiosensitivity enhancement in cervical cancer HeLa cells and explore its mechanism. Methods Logarithmic phase HeLa cells were divided into 3 groups, the negative control group were culture medium, radiotherapy alone group was treated with 6 MV X ray radiation therapy, radiation plus drug group was treated with 20,40 umol / L of celecoxib, for 72 h before radiation therapy. The average lethal dose （ Do）, Quasi-field dose （ Dq）, 2 Gy irradiation of the surviving fraction （ SF2 ） and radiosensitization ratio （SER） was measured by colony formation assay cells radiosensitivity parameters, the expression of cyclooxygenase-2,VEGF-C ,antigen were detected by immunohistochemistry. Results Do , Dq and SF2 in radiation plus drug group were less than the control group （P all 〈 0.05）, its SERDo increased from 2.01 ±0.06 to 2.41 ±0.08. The expression of COX-2, VEGF-C was significantly decreased in radiotherapy plus drug group HeLa cells （ P all 〈 0. 05 ）, compared with the negative control group and radiotherapy alone. Condusion Celecoxib can increase the radiosensitivity of HeLa cells in cancer of the cervix, which might be related to the influence of celecoxib down-regulated the COX-2 ,VEGF-C expression of HeLa cell.