Expression And Promoter Methylation Of FEZ1/LZTS1 Gene In Invasive Micropapillary Carcinoma Of The Breast

ObjectiveStudy the expression of Fez1/Lzts1 protein and the association with clinicopathologic feature in invasive micropapillary carcinoma of the breast(IMPC). And we focused our attention on the epigenetics about the methylation of Fez1/Lzts1 gene promoter to investigate the mechanism of lymph node metastasis of IMPC.MethodsWe analyzed Fez1/Lzts1 protein expression in IMPC and invasive ductal carcinoma,no specific type(IDC-NOS) by IHC.Moreover,we examined and compared the association between Fez1/Lzts1 protein expression and pathological parameters of those two sub-type of the breast cancers.To understand the mechanism of the downregulation of the Fez1/Lzts1 expression,we assessed Fez1/Lzts1 gene promoter methylation status by bisufite sequencing methods,and evaluated the somatic mutation status of Fez1/Lzts1 gene's coding region frame by using DHPLC in amount of cases.Results1.Lymph node metastasis of IMPC was much more severe than that of IDC-NOS(Z=-5.655,P=0.000).2.The expression of Fez1/Lzts1 protein was downregulated both in IMPC and IDC-NOS,and as well as lymph node metastasis,the downregulation of Fez1/Lzts1 was much more significance than that in IDC-NOS(x2=-4.500, P=0.034).3.Downregulation of Fez1/Lzts1 protein was positively correlated with lymph node metastasis both in IMPC and IDC-NOS(P=0.036,P=0.000).4.The AMLs of the 18 CpG islands of FEZ1/LZTS1 promoter in pure-IMPC and IDC-NOS were all significant higher than these of normal tissues (P=0.000,P=0.000).And the AML of pure-IMPC was higher than that of IDC-NOS(t=2.692,P=0.011).Moreover,the AMLs of CpG sites 47,87,127 in pure-IMPC were higher than those in IDC-NOS(P=0.048,P=0.040,P=0.045).5.This was no difference between pure-IMPC and mixed-IMPC samples in the AML of the 18 CpG sites.According to the percentage of IMPC components, mixed-IMPC was devided into two groups.The p AML of the 18 promoter CpG sites was not significantly associated with the percentage of IMPC components.6.Furthermore,the differences of the AML of the 18 CpG islands of FEZ1/LZTS1 were significant in IDC group with metastases and without unmetastases cases(t=2.061,P=0.047).7.Two somatic mutantions were detected in one case amongs the 53 breast cancer cases and the control nomal breast tissues,they were C3927G (Leu＞Val) and G3540A.Conclusion1.Reduced expression of Fezl/Lzts1 protein was significant correlation with lymph node metastases in breast IMPC.2.Promoter methylation would result in downregulation expression of FEZ1/LZTS1.3.The methylation of some CpG sites which were close to transcription initiation might play a more important role in lymph node metastasis of IMPC than in IDC-NOS.5.Mutation is not the main reason of the reduced expression of FEZ1/LZTS1.