The Inhibitory Effect Of C210 On The Quiescent Breast Cancer Cells Under Hypoxia And Glucose Deprive Conditions And Its Mechanism

Tumor dormancy is a poorly understood stage in cancer progression characterized by mitotic cycle arrest in G0/G1 phase and low metabolism.In breast cancer patients,there is a subgroup of cancer cells with slow proliferation,static or dormant state.Although this group of cells is relatively small in number,it is related to chemotherapy resistance,tumor metastasis and recurrence.The cells survive in a quiescent state and wait for appropriate environmental conditions to begin proliferation again giving rise to metastasis.Despite their key role in cancer development and metastasis,the knowledge about their biology and origin is still very limited due to the poorness of established in vitro models that faithfully recapitulated tumor dormancy.Objective:The effect and mechanism of C210 eliminate of quiescent breast cancer cells by inhibiting energy metabolism under low oxygen and low glucose conditions.Method:(1)Under the condition of hypoxia(1%O2)and low glucose(1g/L)for 48 hours,breast cancer MCF-7 and MDA-MB-231 cells were induced to slow proliferation and quiescent state.The proliferation of breast cancer cells and the expression of proliferating protein p38,ERK1/2 and Ki67 were detected by Edu incorporation test,Western blotting test and cellular immunofluorescence assay.(2)Flow cytometry was used to detect the effect of C210 on the apoptosis of quiescent breast cancer cells induced by the above conditions.(3)Distribution of C210 in breast cancer cells by laser confocal microscopy.(4)MTT method was used to detect the cytotoxicity of C210 and doxorubicin to MDA-MB-231 and MCF-7 cells in normoxic culture(21% O2,5% CO2)and hypoxic culture(1% O2,5% CO2).The cytotoxicity of C210 to MDA-MB-231 and MCF-7 cells in serum-free medium and low-glucose medium were detected by MTT method.(5)The action of C210 and known mitochondrial transport chain complex under the above different conditions was detected by MTT method.(6)Construction of TRAP1 knockout breast cancer cell lines by lentivirus transfection.(7)Chemiluminescence method was used to detect the change of ATP level of C210 on breast cancer cells induced by hypoxia and glucose deprive conditions.(8)Western blotting was used to detect the expression of P-AMPK of C210 on breast cancer cells induced by hypoxia and glucose deprive conditions.Result:(1)It was proved that hypoxia(1%O2)and low glucose(1g/L)could induce 80% of MDA-MB-231 and MCF-7 cells to enter the quiescent phase.(2)The chemotherapeutic drug doxorubicin is less sensitive to breast cancer cells induced by hypoxia and low glucose,while C210 can still inhibit the growth of breast cancer cells under hypoxia and hypoglycemia.(3)C210 can distribute and accumulate in the mitochondria of breast cancer cells,and the inhibition of C210 on proliferation of breast cancer cells induced by hypoxia and hypoglycemia may be related to mitochondrial respiration.(4)C210 can inhibit the increase of ATP level and P-AMPK expression in quiescent breast cancer cells induced by hypoxia and low glucose condition.(5)TRAP1 may be related to C210 inhibition of energy metabolism in quiescent breast cancer cells induced by hypoxia and low glucose.Conclusion:Our study provides a promising method to use hypoxia and low glucose conditions to induce breast cancer cells to enter a slow proliferation and quiescent state.Our drug curcumin derivative C210 can reduce the level of cellular ATP by inhibiting mitochondrial respiration,giving priority to inhibiting quiescent breast cancer cells induced by hypoxia and low glucose,resulting in cell death,achieving the effect of clearing quiescent breast cancer cells and improving the effect of chemotherapy on breast cancer.