Objective:To investigate the regulatory mechanism of myoepithelial cells on glandular epithelial cells during the invasive process of ductal carcinoma in situ of breast.Methods:A total of 157 patients with ductal carcinoma in situ of breast,treated at the Tianjin Medical University Cancer Hospital from May 2008 to July 2010,were randomly selected(including 63 high nuclear grade patients,51 middle nuclear grade patients,and 43 low nuclear grade patients).Immunohistochemical staining for epithelial-mesenchymal transition(EMT)-related markers(Snail and ZEB1)was performed on tumor tissue specimens from these patients to explore the correlation between tumor cell nuclear grade,EMT process,and expression status of myoepithelial cells.To further investigate the regulatory role of myoepithelial cells on glandular epithelial cells during the invasive process of ductal carcinoma in situ of breast,a co-culture model of human myoepithelial cell line Hs578Bst and adenomatous epithelial cell line MCF-7 was established using Transwell chambers.Experimental,blank control,positive control,and negative control groups were designed by combining co-cultured Hs578Bst and MCF-7 cells with exogenous TGFβ1 and TGFβ1 inhibitors.After 72 hours of culture,morphological changes,migration and proliferation capabilities of MCF-7,as well as the changes in protein and mRNA expression levels of EMT-related genes(Snail and ZEB1),were observed in each group.Results:Immunohistochemical staining results demonstrated a positive correlation between tumor nuclear atypia,EMT activation,and myoepithelial cell expression in ductal carcinoma in situ tissues.The model of ductal carcinoma in situ of breast demonstrated that myoepithelial cells Hs578Bst promoted morphological changes in glandular epithelial cells MCF-7 by stimulating TGFβ1 expression.Wound healing and cell proliferation assays revealed that myoepithelial cells Hs578Bst can enhance migration and proliferation of glandular epithelial cells MCF-7 via TGFβ1 activation.Western blot and real-time quantitative PCR confirmed that myoepithelial cells Hs578Bst can upregulate the protein and mRNA expression levels of EMT-related genes(Snail and ZEB1)in glandular epithelial cells MCF-7 by through TGFβ1 stimulation.Conclusion:Breast myoepithelial cells promote EMT in glandular epithelial cells by secreting/stimulating TGFβ1,thereby contributing to the occurrence of invasion in ductal carcinoma in situ of the breast.

Objective:To investigate the regulatory mechanism of myoepithelial cells on glandular epithelial cells during the invasive process of ductal carcinoma in situ of breast.Methods:A total of 157 patients with ductal carcinoma in situ of breast,treated at the Tianjin Medical University Cancer Hospital from May 2008 to July 2010,were randomly selected(including 63 high nuclear grade patients,51 middle nuclear grade patients,and 43 low nuclear grade patients).Immunohistochemical staining for epithelial-mesenchymal transition(EMT)-related markers(Snail and ZEB1)was performed on tumor tissue specimens from these patients to explore the correlation between tumor cell nuclear grade,EMT process,and expression status of myoepithelial cells.To further investigate the regulatory role of myoepithelial cells on glandular epithelial cells during the invasive process of ductal carcinoma in situ of breast,a co-culture model of human myoepithelial cell line Hs578Bst and adenomatous epithelial cell line MCF-7 was established using Transwell chambers.Experimental,blank control,positive control,and negative control groups were designed by combining co-cultured Hs578Bst and MCF-7 cells with exogenous TGFβ1 and TGFβ1 inhibitors.After 72 hours of culture,morphological changes,migration and proliferation capabilities of MCF-7,as well as the changes in protein and mRNA expression levels of EMT-related genes(Snail and ZEB1),were observed in each group.Results:Immunohistochemical staining results demonstrated a positive correlation between tumor nuclear atypia,EMT activation,and myoepithelial cell expression in ductal carcinoma in situ tissues.The model of ductal carcinoma in situ of breast demonstrated that myoepithelial cells Hs578Bst promoted morphological changes in glandular epithelial cells MCF-7 by stimulating TGFβ1 expression.Wound healing and cell proliferation assays revealed that myoepithelial cells Hs578Bst can enhance migration and proliferation of glandular epithelial cells MCF-7 via TGFβ1 activation.Western blot and real-time quantitative PCR confirmed that myoepithelial cells Hs578Bst can upregulate the protein and mRNA expression levels of EMT-related genes(Snail and ZEB1)in glandular epithelial cells MCF-7 by through TGFβ1 stimulation.Conclusion:Breast myoepithelial cells promote EMT in glandular epithelial cells by secreting/stimulating TGFβ1,thereby contributing to the occurrence of invasion in ductal carcinoma in situ of the breast.

Objective To study the effects of single nucleotide polymorphisms (SNP) in Plasminogen activator inhibitor 1 (PAI-1) on breast cancer susceptibility and patients' prognosis among a Chinese Han women population.Methods Six tag SNP (tSNP) of PAI-1 were selected according to HapMap CHB population,and TaqMan realtime PCR method was used to genotype the 6 tSNP in 1 160 breast cancer cases and 1 318 age-matched controls among Chinese Han women.Haplotypes and diplotypes were inferred according to genotyping data and linkage disequilibrium.Finally,the associations of tSNP,haplotypes and diphypes with breast cancer susceptibility and patients' prognosis were analyzed.Results Regarding to breast cancer susceptibility,for rs6090 (G ＞ A),AA genotype carriers had 3.79 times higher risk of develoPing breast cancer (OR =4.79,95％ CI =1.01-22.64,P =0.048 0) than GG or GA genotype carriers.For rs2227672 (G ＞ T),TT genotype carriers had 1.52 times higher breast cancer risk than GG or GT genotype carriers (OR =2.52,95％ CI =1.26-5.01,P =0.008 6).Regarding to breast cancer prognosis,women who carried rs2227692 (C ＞ T) CT genotype had 46％ lower risk of developing recurrence,metastasis or death than CC genotype carriers (HR =0.54,95％ CI =0.30-0.97,P =0.040 4).Using stratified association analysis,among BMI ＜ 23 patients,those women who carried AA genotype of rs2227631 (G ＞ A) had 3.99 times higher risk of developing the events (recurrence,metastasis or death) than GG or GA genotype carriers (HR =4.99,95％ CI =1.66-15.02,P =0.004 2).Among HER2 positive patients,those women who carried AA genotype of rs2227667 (G ＞ A) had 2.98 times higher risk of developing the events (recurrence,metastasis or death) than GG or GA genotype carriers (HR =3.98,95％ CI =1.47-10.80,P =0.006 7).Among patients with tumors ＞ 2 cm,those women who carried rs2227692 (C ＞ T) CT or TT genotype had 51％ lower risk of developing the events (recurrence,metastasis or death) than CC genotype carriers (HR =0.49,95％ CI =0.27-0.88,P =0.017 0).Conclusions The study indicates that single nucleotide polymorphisms in PAI-1 may affect breast cancer susceptibility and survival in Chinese Han women.The study may contribute to individualized evaluation of breast cancer risk and patients' prognosis if these data are validated in some other Chinese Han populations.