| BackgroundHuman bone marrow-derived mesenchymal stem cells(MSCs)are closely related to tumor.MSCs not only has the potential of malignant transformation to tumor cells,but also has a significant tumor tendency.MSCs can gather around the tumor through blood circulation to participate in the formation of tumor microenvironment,thus supporting the tumor process.It can be seen that MSCs interact with tumor cells in tumor microenvironment.So,it is not clear whether lung cancer cells can induce MSCs malignant transformation and whether MSCs affect the drug sensitivity of lung cancer or liver cancer cells.ObjectiveIn this paper,we study the malignant transformation of MSCs induced by lung adenocarcinoma cell A549 condition medium,the effect and potential mechanism of MSCs-induced chemotherapy resistance in Non-small cell lung cancer(NSCLC)HCC827 cell line or Hepatocellular Carcinoma(HCC)Hep3B cell line and the intervention effect of effective components from Traditional Chinese Medicine on MSCs-induced chemotherapy resistance in HCC cells,through the interaction between MSCs and tumor cells.MethodsFirstly,MSCs were induced by A549 condition medium(A549-CM),and the effect of A549-CM on MSCs' malignant transformation was studied by detection of cell proliferation and migration,evaluation of the activity of tumor related signaling pathway and tumorigenicity in vivo.Secondly,HCC827 or Hep3 B cells were cultured with MSCs condition medium(MSCs-CM)and treated with Erlotinib or Adriamycin(ADM),respectively.The effect and potential mechanism of MSCs-induced chemotherapy resistance were analyzed by detecting cell survival and apoptosis rate,observing cell morphology,evaluating the activity change of key molecules in chemotherapy resistance related signaling pathways and conducting in vivo experiments.Finally,we treated Hep3 B cells cultured in MSCs-CM with combination of Traditional Chinese Medicine dihydroartemisinin(DHA)and ADM to evaluate the effect of DHA on reversing chemotherapy tolerance induced by MSCs.Results1 MSCs induced by A549-CM exert a certain degree of malignant transformation,which is manifested as: cells with high proliferation phenotype,high migration ability,and obvious tumorigenicity in vivo;significantly improved phosphorylation level of tumor related signal molecules STAT3 and p65 in cells.2 MSCs-CM significantly improves the tolerance of HCC827 cells to Erlotinib,which shows that MSCs CM-cultured HCC827 cells exert increased cell survival rate and decreased apoptosis rate in response to Erlotinib treatment.Mechanism studies show that MSCs enhance AKT and ERK1/2 phosphorylation in HCC827 cells by secreting hepatocyte growth factor(HGF),and then activate the expression of downstream spp1 gene and secretion of osteopontin(OPN).HGF antibody can enhance the killing effect of Erlotinib on MSCs CM-induced HCC827 cells.In the same way,OPN antibody can significantly improve the killing effect of Erlotinib on MSCs CM-induced HCC827 cells.The solid tumors of MSCs and HCC827 cells mixture co-transplanted in mice exert Erlotinib resistance,which is manifested as:significantly increased tumor volume and weight.3 Both MSCs-CM(external cause)and p53(R248Q)mutant(internal cause)can induce the expression of P-glycoprotein(P-gp)in HCC cells.On this basis,HCC cells show a certain degree of ADM tolerance,such as: increased cell survival rate,decreased apoptosis rate and increased ADM efflux.Yet,the comparison results showed that the ADM tolerance induced by MSCs-CM is slightly lower than that induced by p53(R248Q)mutant.The mechanism study shows that MSCs can enhance phosphorylation level of ERK1/2 by secreting HGF,thus promoting expression of P-gp in HCC cells.HGF antibody can enhance the killing efficiency of ADM on HCC cells.4 DHA enhances the sensitivity of HCC cells induced by MSCs-CM or p53(R248Q)mutant to ADM,which is manifested as: decreased survival rate and increased apoptosis rate in HCC cells.The mechanism study shows that DHA inhibit the expression of P-gp by regulating the phosphorylation level of ERK1/2 and p65,thus weakening the ADM efflux in HCC cells.Conclusions1 A549-CM can induce malignant transformation of MSCs to some extent.2 MSCs enhance phosphorylation of AKT and ERK1/2 molecules in NSCLC cells by secreting HGF,thus independent of EGFR's control of PI3K-AKT and MAPK-ERK1/2 signaling pathways,weakening inhibition effect of Erlotinib on AKT and ERK1/2 signals and inducing the expression of drug resistance-related gene spp1,finally leading to Erlotinib resistance in NSCLC cells.3 MSCs induce phosphorylation of ERK1/2 in HCC cells by secreting HGF,which promotes expression of P-gp and ADM efflux,finally enhancing the tolerance of HCC cells to ADM.4 DHA reduces expression of P-gp and ADM efflux efficiency by inhibiting the phosphorylation of ERK1/2 and NF-?B signal molecules,so as to enhance the sensitivity of MSCs or mutant p53(R248Q)-induced HCC cells to chemotherapeutic drugs. |
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