The Role Of FTL Induced By Snail In The Development Of The Breast Cancer

Objective: Breast cancer is the most common cancer and the leading cause of cancer-related death among female,worldwide.Metastasis is a major cause of breast cancer-associated mortality,which means primary tumors metastasis to secondary metastatic sites.In recent years,studies in the association of iron metabolism with breast cancer suggest that the expression of genes and proteins of iron metabolism could be used to evaluate cancer prognosis and to guide therapy.The ferritin light chain(FTL)is overexpressed in several malignancies including breast cancer,liver cancer,colorectal cancer,and pancreatic cancer.However,a number of molecular mechanisms of FTL and breast cancer remain to be elucidated.Snail is a strong inducer of tumor progression and metastasis,and recent study suggest that Snail is also important for the regulation of tumor metabolism.Previous studies have found that Snail can up regulate the expression of FTL in normal breast cells MCF-10 A and breast cancer cells MCF-7,indicating that Snail may induce the expression of FTL in the development and progression of breast cancer.Therefore,we investigated the role of FTL and Snail in breast cancer,and the role of FTL in tumor cell migration and growth.Methods: In order to investigate the real function of Snail and FTL in breast cancer,and the mechanism of how Snail induced the expression of FTL,we first overexpressed and knocked down Snail in multiple cancer cell lines and tested the mRNA levels of FTL by using Real-time PCR.In order to further investigate whether FTL is regulated by Snail,we cloned FTL wild type promoter-luciferase.Snail was cotransfected with FTL promoter into HEK293 T cells and FTL promoter activity was tested by luciferase assay.Next,we first overexpressed and knocked down FTL in MCF-10 A,MCF-7,MDA-MB-231,MCF-10A-plu-vector/snail(Snail overexpressed),MCF-7-plu-vector/snail(Snail overexpressed).Finally,the cell growth and motility were checked by CCK8,Flow cytometry detection and transwell assay.Results: In normal breast cells MCF-10 A and breast cancer cells MCF-7,Snail can increase the expression of the FTL and knockdown Snail can reduce FTL's expression,which not in the MDA-MB-231 cell lines.But Luciferase assay show that Snail may not directly regulate FTL.In FTL overexpressed cell lines,the cell growth and migration ability was enhanced.Consistently,in the cells of knockdown FTL,the growth and migration ability of the cells decreased and the cell cycle was blocked in the G2/M phase.Conclutions: Our result show that Snail can upregulate the expression of FTL,but not through directly bind to the promoter of the FTL.And FTL can promote the growth and migration of breast cancer cell lines.