紫草素逆转由肝细胞生长因子诱导的肺癌吉非替尼耐药

目的:研究肝细胞生长因子(hepatocyte growth factor,HGF)诱导人肺癌HCC827细胞对吉非替尼的耐药以及紫草素(shikonin)逆转此耐药作用的可能机制。方法:体外培养HCC827细胞,分别采用不同浓度的紫草素和吉非替尼单独/联合作用,MTT法检测细胞活力,并计算吉非替尼的半数抑制浓度(half maximal inhibitory concentration,IC₅₀); Transwell小室实验检测紫草素对HGF诱导的吉非替尼耐药HCC827细胞侵袭能力的影响; Western blot检测HGF诱导的吉非替尼耐药HCC827细胞中上皮间质转化(EMT)及相关信号通路蛋白水平的变化。结果:随着给药剂量的增加,紫草素对HCC827细胞的生长抑制率显著上升(P <0. 05),并呈一定的剂量依赖关系,其IC₅₀为3. 06μmol/L。肺癌吉非替尼敏感细胞HCC827对吉非替尼的IC₅₀为0. 51μmol/L。利用不同浓度的HGF诱导吉非替尼耐药,发现20μg/L HGF诱导耐药最为明显,在外源性HGF存在的情况下,HCC827细胞对吉非替尼的IC₅₀为12. 71μmol/L。紫草素能逆转由HGF诱导的吉非替尼耐药(P <0. 05)。Transwell小室实验结果显示,与对照组相比,HGF组能显著提高肺癌HCC827细胞的侵袭能力;同时,紫草素联合吉非替尼作用组则明显抑制由HGF诱导的侵袭(P <0. 01)。Western blot实验结果显示,HGF可诱导HCC827细胞发生EMT,使细胞中E-cadherin蛋白表达下调,vimentin蛋白表达上调,紫草素则能逆转EMT的发生(P <0. 01)。此外,HGF组可激活细胞中AKT蛋白的磷酸化;紫草素联合吉非替尼作用组则能明显抑制由HGF激活的AKT蛋白磷酸化水平(P <0. 01)。结论:紫草素能逆转由HGF诱导肺癌HCC827细胞的吉非替尼耐药,其分子机制可能与逆转EMT和抑制AKT蛋白通路的磷酸化水平有关。

Shikonin reverses HGF-induced resistance to gefitinib in lung cancer cells HCC827

AIM: To investigate the effect of shikonin on reversing hepatocyte growth factor(HGF)-induced resistance to gefitinib in lung cancer HCC827 cells, and to explore its possible mechanisms.METHODS: The gefitinib-resistant HCC827 cells induced by HGF were treated with shikonin and gefitinibthe alone or in combination. The inhibition rates of cell viability were determined by MTT assay. The invasive ability of HCC827 cells with HGF-induced resistance to gefitinib was determined by Transwell assay. The protein levels of epithelial-mesenchymal transition (EMT) and related signaling pathway in the HCC827 cells were detected by Western blot.RESULTS: The results of MTT assay showed that the cell activity of HCC827 cells was significantly inhibited by shikonin in a dose dependent manner. The IC₅₀ of shikonin in HCC827 cells was 3.06 μmol/L. And the IC₅₀ of gefitinib in HCC827 cells was 0.51 μmol/L. Under the condition of combined treatment with shikonin and gefitinib in the presence of HGF (20 μg/L), the IC₅₀ of gefitinib was 7.36 μmol/L, significantly lower than that treated with gefitinib alone (P<0.01), so did the result of the cell migration (P<0.01). HGF induced EMT, while shikonin reversed this effect. The protein expression level of p-AKT was significantly up-regulated by HGF, while markedly down-regulated treatment with shikonin and gefitinib compared with gefitinib alone (P<0.01).CONCLUSION: Shikonin reverses HGF-induced resistance to gefitinib in lung cancer HCC827 cells, and the mechanism may be likely related to the preventon of EMT and the inhibition of HGF-induced activation of p-AKT signaling pathway.