Yanfen Cui

Differential expression of decorin, EGFR and cyclin D1 during mammary gland carcinogenesis in TA2 mice with spontaneous breast cancer.

BackgroundThe Tientsin Albino 2 (TA2) mouse is an inbred strain originating from the Kunming strain. It has a high incidence of spontaneous breast cancer without the need for external inducers or carcinogens. Until now, the mechanism of carcinogenesis has remained unclear. In this study, we investigate differential gene expression, especially the expression of decorin, EGFR and cyclin D1, during mammary gland epithelial cell carcinogenesis in TA2 mice.MethodsGene expression profiles of spontaneous breast cancer and matched normal mammary gland tissues in TA2 mice were ascertained using an Affymetrix Mouse 430 2.0 array. Twelve mammary tissue samples from five month-old female TA2 mice (Group A), as well as 28 samples from mammary (Group B) and cancer tissues (Group C) of spontaneous breast cancer-bearing TA2 mice, were subsequently used to detect the expression of decorin, EGFR and cyclin D1 by real-time PCR and immunohistochemical methods.ResultsSeveral imprinted genes, oncogenes and tumor suppressor genes were differentially expressed between normal mammary gland tissues and breast cancer tissues of TA2 mice. The imprinted gene decorin and the oncogene EGFR were down-regulated in tumor tissues, while the oncogene cyclin D1 was up-regulated. Immunohistochemistry showed that samples in Group A showed high decorin expression more frequently than those in Group B (P < 0.05). More tissue samples in Group B than Group A were positive for nuclear EGFR, and tissue samples in Group B more frequently showed high nuclear EGFR expression than those in Group A or Group C (P < 0.05). The labeling index for cyclin D1 in Group C was significantly higher than in Group B. Mammary tissues of Group A expressed the highest level of decorin mRNA (P < 0.05), and mammary tissues of Group B expressed the highest level of EGFR mRNA (P < 0.05), while cancer tissues expressed the highest level of cyclin D1 mRNA (P < 0.05).ConclusionsThe expression of decorin, EGFR and cyclin D1 in mammary epithelial cells changes with increasing age. The abnormal expression of them may partly contribute to the genesis of spontaneous breast cancer in TA2 mice.

Secreted CLU is associated with the initiation of triple-negative breast cancer

Triple-negative breast cancer, which is negative for the estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2, represents about 15–26% of all breast cancer cases. However, because of its genotype, a triple-negative disease accounts for a remarkable metastasis and mortality. Moreover, no targeted treatment is available because the molecular mechanism of triple-negative breast cancer initiation is still unclear. Secreted clusterin (sCLU) is associated with the refractory to anti-estrogen in breast cancer cells. We investigated the sCLU expression in 384 human breast cancer cases, including 61 triple-negative cases, as well as the relationship between sCLU and clinical pathological characteristics. Triple-negative patients (75.4%) were positive for sCLU based on immunohistochemical analysis, and sCLU expression in this subtype was proven related to a larger tumor size, an axillary node status, and a higher clinical stage. Furthermore, we used a spontaneous breast cancer mouse strain with a triple-negative genotype to detect the sCLU dynamic expression in breast cancer oncogenesis using western blot and real-time polymerase chain reaction. The sCLU mRNA and protein expression in the tumor and hyperplastic epithelium were upregulated and reached a peak compared with those of a normal mammary gland. These results suggest that sCLU is involved in the initiation of triple-negative breast cancer, which is beneficial for the clinical trial design of an anti-CLU treatment for triple-negative breast cancer.

The effect of high gravidity on the carcinogenesis of mammary gland in TA2 mice.

Citation Wang X, Huang C, Sun B, Gu Y, Cui Y, Zhao X, Li Y, Zhang S. The effect of high gravidity on the carcinogenesis of mammary gland in TA2 mice. Am J Reprod Immunol 2010

ORIGINAL ARTICLE: The Effect of High Gravidity on the Carcinogenesis of Mammary Gland in TA2 Mice

Citation Wang X, Huang C, Sun B, Gu Y, Cui Y, Zhao X, Li Y, Zhang S. The effect of high gravidity on the carcinogenesis of mammary gland in TA2 mice. Am J Reprod Immunol 2010

Study on mouse model of triple-negative breast cancer: association between higher parity and triple-negative breast cancer

To investigate the association between high parity and triple-negative breast cancer (TNBC), and explore the etiologic mechanisms of TNBC in Tientsin Albinao 2 (TA2) mice model. After the TA2 mice model with high parity and TNBC had been established, the cell proliferation and apoptosis were detected by immunohistochemical and TUNEL staining in mammary epithelia from different conditions, which included non-pregnancy, low and high gravidity in pregnancy, and carcinogenesis. Apoptotic signaling was analyzed by measuring bcl-2, bax, caspase-3, and caspase-9 expression using immunohistochemistry (IHC), western blot, and real-time PCR technique. Estrogen receptor α (ERα) and progesterone receptor (PR) were determined by immunohistochemical staining and real-time PCR. Both proliferation and apoptosis in mammary epithelia changed with the increasing of parity. Immunohistochemistry revealed increased cell proliferation and apoptosis were related with upregulation of ERα, PR, bcl-2, bax, caspase-3, and caspase-9 expression, especially during the fourth pregnancy. Mammary gland in the fourth pregnancy stage was the closest to precancerous. In precancerous mammary gland, cell proliferation rate was much higher than apoptosis rate. High parity could increase the ovarian hormones level and alter ovarian hormone receptor levels in TA2 mice, and their sensitivity to ovarian hormones result in the imbalance between cell proliferation and apoptosis in precancerous mammary epithelial cells.

ORIGINAL ARTICLE: The Effect of High Gravidity on the Carcinogenesis of Mammary Gland in TA2 Mice: GRAVIDITY ON THE CARCINOGENESIS OF MAMMARY GLAND

Citation Wang X, Huang C, Sun B, Gu Y, Cui Y, Zhao X, Li Y, Zhang S. The effect of high gravidity on the carcinogenesis of mammary gland in TA2 mice. Am J Reprod Immunol 2010