Research Of The Relationship Between LAMC1 And Clinicopathological Characteristics Of Breast Cancer And The Mechanism Of Regulating Breast Cancer Invasion And Metastasis

Objective:To investigate the relationship between laminin ?1(LAMC1)and the clinicopathological characteristics of breast cancer,and to study the mechanism of breast cancer cell proliferation,invasion and metastasis.Method:1.The expression of LAMC1 protein in 200 breast cancer tissues was detected by immunohistochemistry,and the relationship between LAMC1 protein and clinicopathological characteristics was analyzed.2.Western blot was used to detect the expression of LAMC1 protein in normal breast cells(MCF-10A)and four breast cancer cell lines(MCF-7,T-47 D,MDA-MB-231,BT549).3.The LAMC1 overexpressing cell line was constructed by transfecting the LAMC1 overexpression plasmid in breast cancer cell BT549(experimental group B)and the corresponding negative control cell line was established(control group A);A cell line with low expression of LAMC1 gene was constructed by Using shRNA interference technology in breast cancer cell BT549(experimental group C)and the corresponding negative control cell line was established(control group D);CCK-8 assay and Transwell migration and invasion experiments were used to detect the cell proliferation,migration and invasion ability of each group,and Western blot was used to detect the expression levels of MMP9,E-cadherin and N-cadherin in breast cancer cells of each group.Results:1.Immunohistochemistry: The expression of LAMC1 protein in breast cancer tissues was positively correlated with Ki-67 expression,tumor diameter,histological grade,and lymph node metastasis,and the differences were statistically significant(P<0.05).There was no significant correlation between age,ER expression,PR expression,and HER-2 expression,and the differences were not statistically significant(P> 0.05).2.Western blot experiment: The relative expression of LAMC1 protein in normal breast cells MCF-10A(1.000±0.079)was significantly lower than the four breast cancer cell lines MCF-7(1.451±0.062),T-47D(1.653±0.067),MDA-MB-231(1.733±0.082),and BT549(2.078±0.094)(P <0.05),the differences were statistically significant.3.CCK-8 assay:Compared with the control group A(0.383±0.045),the differences of the OD value at the 24 th hour in the experimental group B(0.420±0.054)was not statistically significant(P> 0.05);the OD values at 48h(0.723±0.068)and 72h(1.063±0.102)in the experimental group B were higher than those in the control group A(0.488±0.071)(0.675±0.084)(P<0.05),the difference was statistically significant.Compared with the control group D(0.432±0.057),the differences of the OD value at the 24 th hour in the experimental group C(0.378±0.043)was not statistically significant(P>0.05);the OD values at 48h(0.459±0.066)and 72h(0.583±0.044)in the experimental group C were lower than those in the control group D(0.628±0.073)(0.873±0.052)(P<0.05),the difference was statistically significant.4.Transwell migration experiment: Compared with control group A(185.746±9.823),the number of migrating cells in experimental group B(267.242±13.493)was significantly increased(P<0.01);while compared with control group D(234.201±8.960),the number of migrating cells in experimental group C(154.361±12.917)was significantly reduced(P<0.01),the difference has statistical significane.5.Transwell invasion experiment: Compared with control group A(146.417±9.071),the number of invaded cells in experimental group B(189.392±12.161)was significantly increased(P<0.01);while compared with control group D(186.323±7.290),the number of invaded cells in experimental group C(111.932±10.121)with LAMC1 gene knockdown was significantly reduced(P<0.01),the difference is statistically significant.6.Western blot experiment(detection of three proteins):Compared with control group A(1.000±0.063)(1.000±0.091)(1.000±0.075),the relative expression of MMP9 protein(1.671±0.079)and N-cadherin protein(1.833±0.072)increased and the relative expression of E-cadherin protein(0.481 ± 0.053)decreased(P<0.01)in breast cancer cells of experimental group B(P <0.01);Compared with control group D(1.000±0.087)(1.000±0.081)(1.000±0.055),the relative expression of MMP9 protein(0.532±0.083)and N-cadherin protein(0.453±0.089)decreased and the relative expression of E-cadherin protein(1.703±0.067)increased(P<0.01)in breast cancer cells of experimental group C(P <0.01).Conclusions:1.The expression of LAMC1 protein in breast cancer tissues was positively correlated with Ki-67 expression,tumor diameter,histological grade,and lymph node metastasis.2.The high expression of LAMC1 can promote the proliferation of breast cancer cells and may promote the invasion and migration of breast cancer cells by promoting the expression of MMP9 protein and N-cadherin protein and inhibiting the expression of E-cadherin protein.