OBJECTIVETo explore the effects of adenovirus-delivered tissue inhibitor of metalloprotein- ases-3 (Ad-TIMP-3) on the irradiation sensitivity of human papillomavirus (HPV)-positive cervical cancer cells.

METHODSAn adenovirus expressing TIMP-3 (Ad-TIMP-3), alone or in combination with irradiation,was used to treat HPV-positive cervical cancer cells HeLa-Luc and CaSki. The effects of Ad-TIMP-3 on the proliferation of HeLa-Luc and CaSki cells were detected with MTT assay. The effect of the combination of Ad-TIMP-3 and X-ray on the proliferation of cells were determined by clone formation assay. Twenty nude mice were equally randomly divided into four groups: normal control group,Ad-TIMP-3 group,X-ray group,and combination group. The size of tumor was measured separately,and tumor growth curves were drawn.

RESULTSAd-TIMP-3 significantly inhibited the proliferation of HPV-positive cervical cancer cells in a dose-dependent manner. Combination of Ad-TIMP-3 and X-ray significantly decreased the clones of HeLa-Luc and CaSki than Ad-TIMP-3 or X-ray alone (P<0.05). The tumor weights were (0.216±0.098), (0.276±0.073), and (0.044±0.043) g, respectively, in Ad-TIMP-3 group, X-ray group,and combination group, which were all significantly lower than that in normal control group [(0.534±0.218) g] (all P<0.05). In addition,the tumor weight in the combination group was significantly lower than that in Ad-TIMP-3 group and X-ray group (both P<0.05). The tumor inhibition rate was 59.60%, 48.30%, and 91.80% in X-ray group, Ad-TIMP-3 group and combination group, respectively.

CONCLUSIONSAd-TIMP-3 can effectively inhibit the proliferation of cervical cancer cells. When combined with X-ray,it can remarkably increase the irradiation sensitivity of HPV-positive cervical cancer cells,and thus suppress the tumorigenesis capability of these cells in vivo.