Shuanghuang Shengbai granule cures myelosuppression and suppresses lung cancer progression: mechanism and therapeutic targets from the aspect of microRNAs.

BACKGROUND: Shuanghuang Shengbai granule is effective in curing cyclophosphamide-induced myelosuppression without promoting lung cancer development. This study aims to investigate its mechanism and therapeutic targets.

METHODS: Nude mice with lung cancer were treated with physiological saline (control), cyclophosphamide, or cyclophosphamide + Shuanghuang Shengbai. MicroRNA microarray was used to investigate the differentially expressed microRNAs in lung cancer stem cells or bone marrow hematopoietic stem cells between the three groups. MicroRNA expressions were confirmed using quantitative real time-polymerase chain reaction.

RESULTS: Cyclophosphamide suppressed tumor growth and decreased the ratio of SP(+) lung cancer stem cells (P<0.05). Shuanghuang Shengbai further decreased the ratios of SP(+) and CD24(+)IGF1R(+) lung cancer stem cells (P<0.05). Shuanghuang Shengbai completely reversed the cyclophosphamide-induced decreases in white blood cells, proliferation index of bone marrow cells, and the ratio of CD34(+)SCA1(+) bone marrow hematopoietic stem cells (P<0.05). We found 45 and 343 altered microRNAs for SP(+) lung cancer stem cells and CD34(+)SCA1(+) bone marrow hematopoietic stem cells, respectively. Moreover, miR-32*, miR-466i-5p, and mmu-miR-669c in SP(+) lung cancer stem cells were confirmed, as well as mmu-miR-106b*, mmu-miR-144, mmu-miR-669k*, mmu-miR-142-3p, mmu-miR-210, and mmu-miR-223 in CD34(+)SCA1(+) bone marrow hematopoietic stem cells.

CONCLUSION: Shuanghuang Shengbai might promote the proliferation of CD34(+)SCA1(+) bone marrow hematopoietic stem cells via up-regulating mmu-miR-106b*, mmu-miR-144, and mmu-miR-669k*, as well as down-regulating mmu-miR-142-3p, mmu-miR-210, and mmu-miR-223. Shuanghuang Shengbai might further inhibit the proliferation of SP(+) lung cancer stem cells via enhancing the expressions of miR-32*, miR-466i-5p, and mmu-miR-669c. These might be the mechanism and therapeutic targets of Shuanghuang Shengbai granule.