[Role of endoplasmic reticulum protein folding molecular chaperones in floxuridine-resistance choriocarcinoma JeG-3/FUDRA cell line].

OBJECTIVE: To investigate changes of protein expression profiles between human choriocarcinoma JeG-3 cell line and its floxuridine (FUDR)-resistant sub-line. METHODS: The differentially expressed proteins were identified by using two dimension difference gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) approaches. Gene ontology (GO) analysis and Pathway analysis were used to screen the candidate proteins. The levels of the proteins in chemo-resistant sub-lines were validated by western blot. Ribonucleic acid interference (RNAi) was used to knockdown the expression of calreticulin (CALR) and (or) protein disulfide-isomerase A3 (PDIA3) respectively. RESULTS: Forty-six proteins spots were found to be significantly different in spot intensity by statistical analysis between chemo-resistance sub-line and parent cell line, of which 31 proteins were identified by MALDI-TOF-MS. Comparing to the parent cell lines, three endoplasmic reticulum (ER) protein folding molecular chaperones: CALR, PDIA3 and 78 000 glucose-regulated protein (GRP78) screened out were increased significantly in floxuridine-resistant sub-line and were verified by western blot. The resistance index decreased by knockdown the CALR and/or PDIA3 expression in FUDR-resistant sub-line 76.3% (36.7 ± 2.0 vs. 8.7 ± 3.1, P < 0.05) and 51.4% (36.7 ± 2.0 vs. 17.8 ± 1.2, P < 0.05) respectively. CONCLUSION: These ER protein folding molecular chaperones, CALR, PDIA3 and GRP78, may involved in the mechanism of FUDR-resistance choriocarcinoma.

[Effect of adenovirus delivered tissue inhibitor of metalloproteinases 3 on the irradiation sensitivity of human papillomavirus positive cervical cancer cells].

OBJECTIVE: To 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. METHODS: An 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. RESULTS: Ad-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. CONCLUSIONS: Ad-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.