Effect Of PGC-1α On Mitochondria-mediated Tumor-associated Macrophage Polarization Status On Breast Cancer Cell Metastatic Potential And Its Possible Mechanism

Objective: To investigate the polarization status of TAMs and mouse breast cancer cells by peroxisome proliferator-activated receptor γcoactivator-1α(PGC-1α)in tumor associated macrophages(TAMs)(4T1)Effects of biological characteristics.Methods:(1)To determine the expression of PGC-1α,mitochondrial function and polarization of TAMs in TAMs: mouse peritoneal macrophages(PMs)were used as the research object,and TAMs were established by co-culture with 4T1 cells for 24 hours.Cells;sh RNA transfection to construct TAMs cells with transient low expression of PGC-1α;the experiment was divided into three groups: control group(PMs group),TAMs group,sh-PGC-1α TAMs group;Western blot detection of PGC-1α,TAMs in TAMs The mt DNA levels of TAMs were detected by Real-time PCR(q RT-PCR);the polarized markers of TAMs were detected by flow cytometry,and the ROS levels were changed;ATP assay kit was used to detect ATP in TAMs.The level of change.(2)To determine the effect of PGC-1α on the biological characteristics of 4T1 cells in TAMs cells: 4T1 cells were co-cultured with PMs cells or PMs cells with low PGC-1α to establish TAMs or sh-PGC.-1α TAMs cells;the experimental group was divided into 3 groups: control group(4T1 group),TAMs group,sh-PGC-1α TAMs group.Western Blot was used to detect the expression of E-cadherin and vimentin in epithelial-mesenchymal transition(EMT)of4T1 cells;Transwell invasion and migration assay to detect invasion and migration of 4T1 Ability;wound healing assay to detect the cell healing ability of 4T1 cells.Results: PMs cells were used as research objects.Compared with PMs group,PGC-1α protein expression was up-regulated in TAMs group(P<0.05)and M2-type secreted cytokine protein(TGF-β1,IL-10)expression was increased(P<0.05),mitochondrial function-related protein(NRF-1).TFAM)increased expression(P<0.05),M2 type polarization marker(CD206)expression increased(P<0.05),and M1 type secreted cytokine protein(TNF-α,IL-1β)expression decreased(P< 0.05);sh-PGC-1α TAMs group had opposite changes compared with TAMs group,ie,PGC-1α protein expression decreased(P<0.05),and M2 type secreted cytokine protein(TGF-β1,IL-10)expression decreased(P<0.05).<0.05),decreased expression of mitochondrial function-related protein(NRF-1,TFAM)(P<0.05),decreased expression of M2-type polarization marker(CD206)(P<0.05),M1-type secreted cytokine protein(TNF-α)The expression of IL-1β)was increased(P<0.05),and the expression of M1 type polarization marker(CD86)was increased(P<0.05).4T1 cells were used as research objects.Transwell invasion test showed that the difference of 4T1 invasion ability between the three groups was statistically significant(F=29.668,P<0.05).Transwell migration assay showed that the difference in migration ability of 4T1 cells was statistically significant(F=13.193,P<0.05).The results of wound healing experiments showed that the difference in cell healing ability of 4T1 cells was statistically significant(F=42.435,P<0.05).Western blot analysis showed that the expression of EMT epithelial markers(E-cadherin)and EMT interstitial markers(vimentin)were statistically significant(F=87.295,79.058,P<0.05).Compared with the control group(4T1 group),the expression of E-cadherin was significantly decreased in the TAMs group(1 vs 0.44±0.11,P<0.05).Compared with the TAMs group,the expression of E-cadherin was significantly increased in the sh-PGC-1α TAMs group(0.44 ±0.11 vs2.51±1.67,P<0.05).Compared with the control group(4T1 group),the expression of vimentin was significantly increased in the TAMs group(1 vs2.20±0.15,P<0.05).Compared with the TAMs group,the vimentin expression in the sh-PGC-1α TAMs group was significantly decreased(2.20±0.15 vs 0.36 ±0.10,P<0.05).Conclusion: PGC-1α is involved in the polarization of breast TAMs to M2.The mechanism may be that cancer cells interact with TAMs,enhance the mitochondrial function of PGC-1α in TAMs,promote cell differentiation to M2,and produce M2 cells.factor.At the same time,it promoted the EMT process of 4T1 cells and enhanced the invasion,migration and cell healing ability of 4T1 cells.