[RelE toxin protein of Mycobacterium tuberculosis induces growth inhibition of lung cancer A-549 cell].

Objective To investigate whether the RelE toxin protein of mycobacterium tuberculosis has a growth inhibition effect on lung cancer A-549 cell. Methods The complete open-reading frame sequences of RelE, RelB and RelBE genes were amplified by PCR with using M.tuberculosis H37Rv genomic DNA as the template. The RelE, RelB and RelBE genes were subcloned into PcDNA3.1(+). After being verified with restriction endonuclease digestion and DNA sequence determination, the recombinant vectors were applied to transfect lung cancer A-549 cells by liposome transfection method. By determining the growth curve and protein level of living cells, MTT cell proliferation assay, the apoptosis of cells with HE staining and the apoptosis rate of transient transfection cells detected by Flow Microfluorimetry, it was observed and analyzed whether the RelE toxin protein of mycobacterium tuberculosis had a growth inhibition and apoptosis effects on lung cancer A-549 cell. Results The cell proliferation rate of lung cancer A-549 cells effected by the RelE toxin protein of mycobacterium tuberculosis was lower than that of the other groups, and this group cells with RelE protein effect showed more sensitive to nutrition starving. HE staining revealed that this group cells which included the transient transfection with RelE expression plasmid appeared to have more apoptosis cells and higher apoptotic rate than other groups did(P0.05). Conclusion The RelE toxin protein of mycobacterium tuberculosis has growth inhibition and apoptotic effect on lung cancer A-549 cell.