[Effects of adenoviral-mediated mda-7/IL-24 gene infection on the growth and drug-resistance of drug-resistant].

Objective: To study the effects of tumor suppressor gene mda-7/IL-24 on the growth and drug-resistance of two drug-resistant ovarian cancer cell lines OVCAR-3, OVCAR-8/TR.

Methods: Adenoviral-mediated mda-7/IL-24 (Ad. mda-7/IL-24) was constructed in our previous study, and then applied to infect two cell lines. Western blot analysis was used to detect the expression of MDA-7/IL-24 protein. The cell viability and resistance against four chemotherapeutic drugs, including DDP, ADM, 5-FU and Taxol, were examined with methyl thiazolyl tetrazolium (MTT) rapid photocolorimetric assay.

Results: All OVCAR-8/TR and OVCAR-3 cells were infected under the condition that Ad. mda-7/IL-24 was 10 microL, and successfully infected cells could express the MDA-7/IL-24 protein. OVCAR-3 and OVCAR-8/TR cell growth were significantly inhibited after cells infected by Ad. mda-7/IL-24. The cell viability decreased to 10. 5% and 35. 8% respectively in the fifth day. The sensitivity of infected OVCAR-3 or OVCAR-8/TR to Taxol was increased up to 2. 76 or 1. 52 times, as compared with the control. The infected OVCAR-3 cells also had higher sensitivity to ADM and 5-FU, which digitally increased respectively 1. 6 and 3. 01 times when compared to the sensitivities before cells infected.

Conclusion: The mda-7/IL-24 gene shows cancer growth inhibition on drug-resistance ovarian caner cell lines. Ad. mda-7/IL-24 infecting cell may have the capability of reversing the resistance of tumor cell against Taxol.