Tanshinone IIA enhances the inhibitory effect of imatinib on proliferation and motility of acute leukemia cell line TIB-152 in vivo and in vitro by inhibiting the PI3K/AKT/mTOR signaling pathway

Acute lymphoblastic leukemia (ALL) is a malignant hematological disease. Tanshinone IIA (Tan IIA) has antitumor activity in vitro and in vivo. The aim of the present study was to investigate the effects of Tan IIA in combination with imatinib (IM) on the proliferation, apoptosis, migration and invasion of acute T lymphocytic leukemia TIB-152 cells in vivo and in vitro, and analyze the potential underlying mechanism. Tan IIA and IM, alone and in combination, significantly inhibited proliferation, migration and invasion of TIB-152 cells, and promoted apoptosis; the effect of co-treatment with Tan IIA plus IM was enhanced. IGF-1 promoted the proliferation, migration and invasion of TIB-152 cells and inhibited apoptosis, while Tan IIA treatment significantly reversed these effects. In vivo experiments demonstrated that treatment with Tan IIA and IM, alone or in combination, significantly inhibited tumor growth in TIB-152 ×enograft mice; the growth inhibition of Tan IIA plus IM was the strongest observed. Western blot analysis revealed that the combination of Tan IIA and IM resulted in significantly lower levels of p-PI3K, p-AKT and p-mTOR in cells and tissues compared with the IM and Tan alone treatment groups. In addition, the combination of Tan IIA and IM significantly decreased the levels of Ki67, cleaved caspase-3, VEGF and MMP-9 in cells and tissues, and the level of caspase-3 was significantly increased. Taken together, the results revealed that Tan IIA enhanced the inhibitory effect of imatinib on TIB-152 cell proliferation, migration and invasion, and induced apoptosis, which may be associated with inhibition of the PI3K/AKT/mTOR signaling pathway.