Abstract:

Objective： To investigate the effects of different concentrations of traditional Chinese medicine indirubin derivative E804 on the proliferation， apoptosis and differentiation of non-small cell lung cancer （NSCLC） A549 cells， and to clarify its possible mechanism. Methods The NSCLC A549 cells were cultured in vitro and divided into control group （0 μmol·L^－1 E804） and different concentrations（2.5， 5.0 and 10.0 μmol·L^－1） of E804 groups. MTT assay was used to detect the proliferation rates of cells in various groups； cell scratch assay was used to detect cell migration abilities in various groups； soft agar cloning assay was performed to observe cell differentiation and colony formation abilities in various groups； flow cytometry was used to detect apoptotic rates of cells in various groups； Western blotting method was used to detect the expression levels of apoptosis-related proteins and Janus kinase 1 （JAK1）/signal transducer and activator of transcription 3 （STAT3） signaling pathway-related proteins in the cells in various groups. Results The MTT assay results showed that compared with control group，the proliferation rates of A549 cells in 2.5， 5.0 and 10.0 μmol·L^－1 E804 groups were significantly decreased（P<0.05 or P<0.01） in a time- and concentration-dependent manner； the cell scratch and soft agar cloning methods results showed that compared with control group， the migration distance and the number of colony formation of the cells in 2.5， 5.0 and 10.0 μmol·L^－1 E804 groups were decreased（P<0.05 or P<0.01）. The flow cytometry results showed that compared with control group， the apoptotic rates in 2.5， 5.0 and 10.0 μmol·L^－1 E804 groups were increased（P<0.05 or P<0.01）.The Western blotting method results showed that compared with control group， the expression levels of B-cell lymphoma-2（Bcl-2），phosphorylated JAK1（p-JAK1） and phosphorylated STAT3（p-STAT3） proteins in the cells in 2.5， 5.0 and 10.0 μmol·L^－1 E804 groups were decreased（P<0.05 or P<0.01）， while the expression levels of Bcl-2 related X protein（Bax）， cleaved cysteinyl aspartate specific proteinase-3（cleaved caspase-3） and cleaved cysteinyl aspartate specific proteinase-9（cleaved caspase-9）proteins were increased（P<0.05 or P<0.01）. Conclusion E804 can inhibit the proliferation， migration and differentiation of A549 cells in vitro， and induce their apoptosis， and its mechanism may be related to the down-regulation of expressions of JAK1/STAT3 signaling pathway-related proteins.

Key words: Lung naoplasms, Chinese medicine indirubin derivatives, Apoptosis, Janus kinase 1, Signal transducer and activator of transcription 3