Mechanism Of Id4 Gene Expression In Nano-Magnetic Hyperthermia Of Breast Cancer MCF-7 Cells

Breast cancer is the most common cancer in women,and mortality is lower than of lung cancer.At present,the breast cancer clinical treatment is mainly surgery combined with radiotherapy and chemotherapy,as well as endocrine and targeted therapy.The main obstacle to the treatment of breast cancer is recurrence and drug resistance,making breast cancer patients with poor prognosis.In recent years,magnetic hyperthermia play an important role in the clinical treatment of tumors.Magnetic hyperthermia kills cancer cells by heating the tumor area,and has been applied in the clinical treatment of glioma.Although magnetic hyperthermia is developing rapidly,the biological effects of magnetic hyperthermia are unclear.Using Fe₃O₄ nanoparticles as a thermotherapy agent,we explored the mechanism of magnetic hyperthermia treatment of breast cancer MCF-7 cells.Combining transcriptome sequencing to analyze the difference of gene expression during magnetic hyperthermia,we looked for effective magnetic hyperthermia molecular markers.Experimental results show:The Fe₃O₄ nanoparticles prepared by high-temperature synchronous thermal decomposition method have uniform size,good dispersibility,and the average particle size is 16 nm;Cytotoxicity experiments showed that the prepared Fe3O4nanoparticles exhibited good cell compatibility when the Fe concentration less than 100μg/mL.Extracellular-MHT and Intracellular-MHT have the same temperature,reaching46℃after 10 minutes.However,in the I-MHT group,cell death was 80%,and in the E-MHT group,only 20%died.In the whole transcriptome sequencing,compared with the control group（MCF-7 cells without any treatment）,396 genes in the I-MHT group were up-regulated,and the E-MHT group was not significantly different.By enriching the differentially expressed genes in the I-MHT group,it was found that the Id4 gene in the TGF-beta signaling pathway involved in cell proliferation,differentiation,and cancer development was significantly down-regulated and was performed.We interfered with the expression of Id4 gene by siRNA and found that the magnetic hyperthermia effect of MCF-7 cells was further enhanced;and using Lentivirus to overexpress of Id4 in MCF-7cells results in the acquisition of resistance to magnetic hyperthermia.This study suggests that down-regulation of Id4 gene expression can enhance magnetic hyperthermia in breast cancer MCF-7 cells,and Id4 gene plays an important role in tumor magnetic hyperthermia.