The Study Of DPP3 In Luminal A Breast Cancer

1.Research Background:Breast cancer is a malignant tumor that seriously threatens human life and health,and the latest cancer statistics show that breast cancer has replaced lung cancer as the cancer with the highest diagnosis rate in the world,and breast cancer is also one of the malignant tumors with the highest fatality rate.Although the current molecular typing of breast cancer(Luminal A,Luminal B,HER2-positive,triple-negative breast cancer,etc.)has shown significant clinical application value and brought benefits to the majority of breast cancer patients,there are still large differences in efficacy in patients with the same type of breast cancer when receiving the same treatment.Among them,Luminal type A breast cancer,as the most common type of breast cancer,has achieved certain therapeutic results clinically,but it still plagues the majority of women as a malignant tumor,so Luminal type A breast cancer has great research significance.Further exploring the mechanism of breast cancer occurrence and development and finding novel molecular markers will have long-term significance for solving the individualized and precise treatment of Luminal type A breast cancer.Dipeptidyl peptidase Ⅲ(DPP3),the sole representative of the M49 metallopitidase family,is a zinc-dependent aminopeptidase.DPP3 is cytoplasmic and membrane localized,can bind to specific zinc-binding motifs(HELLGH),and has postproline dipeptide aminopeptidase activity.,can cleave and degrade bioactive peptides,including angiotensin,leucine enkephalin,enkephalin.DPP3 is expressed in a variety of organs and affects a variety of physiological and pathological processes.The literature has verified that DPP3 has a cancer-promoting effect in colon cancer,glioblastoma,esophageal cancer and liver cancer.However,the role and mechanism of DPP3 in breast cancer are still poorly studied.Therefore,based on the database analysis results and Western Blot experimental results,this project selected the Luminal A breast cancer cell line to study and analyze the biological function of DPP3 on Luminal A breast cancer,and explore the signaling pathways of DPP3 in the biological function of Luminal A breast cancer cell line,and further study the influence mechanism of DPP3 on the occurrence and development of Luminal A breast cancer.2.Methods:(1)A variety of databases were used to analyze the upregulation of DPP3 expression in breast cancer,and the correlation between DPP3 and the prognosis of various types of breast cancer was further clarified.(2)Seven existing breast cancer cell lines in the laboratory were selected for culture,and the DPP3 expression profile was verified by Western Blot experiment and q PCR experiment.(3)The si RNA corresponding to DPP3 was constructed,and the si RNA was transferred into MCF-7 and T47 D cell lines to knock down DPP3 by instantaneous,and then the transfection efficiency was verified from the protein and m RNA levels.(4)The changes of cell proliferation before and after DPP3 knockdown were compared by CCK-8 experiment and colony formation experiment;The apoptosis experiment was performed to detect apoptosis before and after DPP3 knockdown,and the effect of DPP3 on apoptosis in Luminal type A breast cancer was analyzed.(5)The effect of DPP3 on iron death in Luminal A breast cancer cells was analyzed by cell lipid peroxidation(Lipid ROS)level detection experiment.(6)The ELISA experiment was used to detect the content of IL-18 in the cell culture supernatant,and the Western blot experiment was used to detect the related proteins of the classical pyrozoosis pathway relying on Caspase-1,and the effect of DPP3 on pyroptosis in Luminal A breast cancer cells was analyzed.(7)Prediction of DPP3-related signaling pathways by RNA sequencing(RNA-seq)analysis.The Western blot experiment was used to detect the correlation between DPP3 expression levels and related proteins of the NOD-like receptor signaling pathway.3.Results:(1)The results of database analysis showed that the expression of DPP3 in breast cancer tissues was upregulated compared with normal breast tissue,and was associated with poor prognosis of Luminal type A breast cancer.(2)The results of Western blot showed that DPP3 was significantly expressed in MCF-7 and T47 D cell lines,and the DPP3 knockdown cell line was constructed,CCK8 experiments showed that knocking down DPP3 could significantly inhibit the proliferation of breast cancer cells,while the flow cytometry results showed that knocking down DPP3 could promote apoptosis of T47 D cells,and the results of ELISA and Western blot experiments showed that knocking down DPP3 could promote coke of T47 D cells.(3)The results of RNA sequencing analysis showed that DPP3 was closely related to NOD-like receptor signaling pathway,and it was further verified by Western blot that DPP3 can promote NOD-like receptor signaling pathway and thus promote the occurrence and development of breast tumors.4.Conclusions:(1)Upregulation of DPP3 expression was associated with poor prognosis of Luminal type A breast cancer;(2)The expression level of DPP3 in Luminal type A breast cancer cell line was increased;(3)Knockdown DPP3 inhibits the proliferation of Luminal type A breast cancer cell lines;(4)Knocking out DPP3 promotes apoptosis of T47 D cells;(5)Knocking out DPP3 promotes pyroptosis in T47 D cells(6)DPP3 achieves its cancer-promoting effect in T47 D cells by affecting the NOD-like receptor signaling pathway.