Department of Experimental Therapeutics, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030-4009, USA.
Cancer. 2010 Nov 1;116(21):4980-90. doi: 10.1002/cncr.25426.
Dasatinib, an inhibitor of Src/Abl family kinases, can inhibit tumor growth of several solid tumors. However, the effect and mechanism of action of dasatinib in human ovarian cancer cells remains unknown.
Dasatinib-induced autophagy was determined by acridine orange staining, punctate localization of GFP-LC3, LC3 protein blotting, and electron microscopy. Significance of beclin 1, AKT, and Bcl-2 in dasatinib-induced autophagy and growth inhibition was assayed by small interfering RNA (siRNA) silencing and/or overexpression of the gene of interest.
Dasatinib inhibited cell growth by inducing little apoptosis, but substantial autophagy in SKOv3 and HEY ovarian cancer cells. In vivo studies showed dasatinib inhibited tumor growth and induced both autophagy and apoptosis in a HEY xenograft model. Knockdown of beclin 1 and Atg12 expression with their respective siRNAs diminished dasatinib-induced autophagy, whereas knockdown of p27Kip1 with specific siRNAs did not. Small hairpin RNA knockdown of beclin 1 expression reduced dasatinib-induced autophagy and growth inhibition. Dasatinib reduced the phosphorylation of AKT, mTOR, p70S6K, and S6 kinase expression. Constitutive expression of AKT1 and AKT2 inhibited dasatinib-induced autophagy in both HEY and SKOv3 cells. Dasatinib also reduced Bcl-2 expression and activity. Overexpression of Bcl-2 partially prevented dasatinib-induced autophagy.
Dasatinib induces autophagic cell death in ovarian cancer that partially depends on beclin 1, AKT, and Bcl-2. These results may have implications for clinical use of dasatinib.
达沙替尼是一种Src/Abl 家族激酶抑制剂，可抑制多种实体肿瘤的肿瘤生长。然而，达沙替尼在人卵巢癌细胞中的作用和作用机制尚不清楚。
通过吖啶橙染色、GFP-LC3 点状定位、LC3 蛋白印迹和电子显微镜观察确定达沙替尼诱导的自噬。通过小干扰 RNA（siRNA）沉默和/或感兴趣基因的过表达测定 beclin 1、AKT 和 Bcl-2 在达沙替尼诱导的自噬和生长抑制中的意义。
达沙替尼通过诱导少量细胞凋亡但大量自噬抑制 SKOv3 和 HEY 卵巢癌细胞的生长。体内研究表明，达沙替尼抑制肿瘤生长并在 HEY 异种移植模型中诱导自噬和凋亡。用相应的 siRNA 敲低 beclin 1 和 Atg12 的表达可减少达沙替尼诱导的自噬，而用特异性 siRNA 敲低 p27Kip1 则不会。beclin 1 表达的短发夹 RNA 敲低减少了达沙替尼诱导的自噬和生长抑制。达沙替尼降低了 AKT、mTOR、p70S6K 和 S6 激酶表达的磷酸化。AKT1 和 AKT2 的组成型表达抑制了 HEY 和 SKOv3 细胞中达沙替尼诱导的自噬。达沙替尼还降低了 Bcl-2 的表达和活性。Bcl-2 的过表达部分阻止了达沙替尼诱导的自噬。
达沙替尼在卵巢癌中诱导自噬性细胞死亡，部分依赖于 beclin 1、AKT 和 Bcl-2。这些结果可能对达沙替尼的临床应用有意义。
