The primary interest of my group is mouse genetics and mammary gland tumorigenesis using animal model systems. We have been studying three groups of genes, including functions of fibroblast growth factor receptors (FGFRs), Smad genes, and breast tumor suppressor gene (BRCA1). We are currently focusing on functional analysis of BRCA1 in cell cycle checkpoint, genetic stability, aging and tumorigenesis. Breast cancer is the most common cancer and the second leading cause of cancer mortality in women, with approximately one in 9 being affected over their lifetime. In the past several years, we have introduced a series of mutations-including a null mutation, an isoform mutation, and a conditional mutation-into the mouse BRCA1 locus. Mutational analyses at both cellular and whole animal levels demonstrated that the primary function of BRCA1 is to maintain genome integrity through its control over the G2-M cell cycle checkpoint, spindle checkpoint, and centrosome duplication. BRCA1 mutations result in genetic instability, which then activates cellular protection mechanisms, including cell-cycle checkpoints and programmed cell death, to eliminate the mutant cells. This is why BRCA1 mutant cells fail to grow in culture. On the other hand, the genetic instability in BRCA1 mutant cells theoretically increases mutation rates of all genes, including tumor suppressors and oncogenes, which ultimately overcomes the proliferation defects caused by the BRCA1 loss and results in tumor formation. We are continuing to study mechanisms of BRCA1 associated tumorigenesis and seeking efficient ways of prevention and therapeutic treatment of this deadly disease.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Intramural Research (Z01)
Project #
1Z01DK056001-08
Application #
7337500
Study Section
(GDDB)
Project Start
Project End
Budget Start
Budget End
Support Year
8
Fiscal Year
2006
Total Cost
Indirect Cost
Name
U.S. National Inst Diabetes/Digst/Kidney
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Lahusen, Tyler J; Deng, Chu-Xia (2015) SRT1720 induces lysosomal-dependent cell death of breast cancer cells. Mol Cancer Ther 14:183-92
Cao, Liu; Xu, Xiaoling; Cao, Longyue L et al. (2007) Absence of full-length Brca1 sensitizes mice to oxidative stress and carcinogen-induced tumorigenesis in the esophagus and forestomach. Carcinogenesis 28:1401-7
Tominaga, Y; Wang, A; Wang, R-H et al. (2007) Genistein inhibits Brca1 mutant tumor growth through activation of DNA damage checkpoints, cell cycle arrest, and mitotic catastrophe. Cell Death Differ 14:472-9
De Soto, Joseph A; Wang, Xianyan; Tominaga, Yohei et al. (2006) The inhibition and treatment of breast cancer with poly (ADP-ribose) polymerase (PARP-1) inhibitors. Int J Biol Sci 2:179-85
Smolen, Gromoslaw A; Muir, Beth; Mohapatra, Gayatry et al. (2006) Frequent met oncogene amplification in a Brca1/Trp53 mouse model of mammary tumorigenesis. Cancer Res 66:3452-5
Overholtzer, Michael; Zhang, Jianmin; Smolen, Gromoslaw A et al. (2006) Transforming properties of YAP, a candidate oncogene on the chromosome 11q22 amplicon. Proc Natl Acad Sci U S A 103:12405-10
Kim, Byung-Gyu; Li, Cuiling; Qiao, Wenhui et al. (2006) Smad4 signalling in T cells is required for suppression of gastrointestinal cancer. Nature 441:1015-9
Gautam, Dinesh; Han, Sung-Jun; Hamdan, Fadi F et al. (2006) A critical role for beta cell M3 muscarinic acetylcholine receptors in regulating insulin release and blood glucose homeostasis in vivo. Cell Metab 3:449-61
Kim, Sang Soo; Cao, Liu; Lim, Sung-Chul et al. (2006) Hyperplasia and spontaneous tumor development in the gynecologic system in mice lacking the BRCA1-Delta11 isoform. Mol Cell Biol 26:6983-92
Xu, Xiaoling; Kobayashi, Shogo; Qiao, Wenhui et al. (2006) Induction of intrahepatic cholangiocellular carcinoma by liver-specific disruption of Smad4 and Pten in mice. J Clin Invest 116:1843-52

Showing the most recent 10 out of 96 publications