Prognostic value genotypes and LOH at TP53 codon 72 and TP53mutations in primary breast cancer
Breast Cancer Research
There is compelling evidence from transgenic mouse studies and analysis of mutations in human carcinomas indicating that the TGF-β signal transduction pathway is tumor suppressive. We have shown that overexpression of TGF-β1 in mammary epithelial cells suppresses the development of carcinomas and that expression of a dominant negative type II TGF-β receptor (DNIIR) in mammary epithelial cells under control of the MMTV promoter/enhancer increases the incidence of mammary carcinomas. Studies of
... man tumors have demonstrated inactivating mutations in human tumors of genes encoding proteins involved in TGF-β signal transduction, including DPC4/Smad4, Smad2, and the type II TGF-β receptor (TβRII). There is also evidence that TGF-β can enhance the progression of tumors. This hypothesis is being tested in genetically modified mice. To attain complete loss of TβRII, we have generated mice with loxP sites flanking exon 2 of Tgfbr2 and crossed them with mice expressing Cre recombinase under control of the MMTV promoter/enhancer to obtain Tgfbr2 mgKO mice. These mice show lobuloalveolar hyperplasia. Mice are being followed for mammary tumor development. Tgfbr2 mgKO mice that also express polyoma virus middle T antigen under control of the MMTV promoter (MMTV-PyVmT) develop mammary tumors with a significantly shorter latency than MMTV-PyVmT mice and show a marked increase in pulmonary metastases. Our data do not support the hypothesis that TGF-β signaling in mammary carcinoma cells is important for invasion and metastasis, at least in this model system. The importance of stromal-epithelial interactions in mammary gland development and tumorigenesis is well established. These interactions probably involve autocrine and paracrine action of multiple growth factors, including members of the TGF-β family, which are expressed in both stroma and epithelium. Again, to accomplish complete knockout of the type II TGF-β receptor gene in mammary stromal cells, FSP1-Cre and Tgfbr2 flox/flox mice were crossed to attain Tgfbr2 fspKO mice. The Despite over a decade of scrutiny and over 20 published reports from various countries, the degree to which ATM mutations lead to breast References 1. Gatti RA, Tward A, Concannon P: Cancer risk in ATM heterozygotes: a model of phenotypic and mechanistic differences between missense and truncating mutations. Mol Biol Metab 1999, 68:419-423. 2. Spring K, Ahangari F, Scott SP, Waring P, Purdie DM, Chen PC, Hourigan K, et al.: Mice heterozygous for mutation in Atm, the gene involved in ataxia-telangiectasia, have heightened susceptibility to cancer. Nat Genet 2002, 32:185-190. 3. Scott SP, Bendix R, Chen P, Clark R, Dork T, Lavin MF: Missense mutations but not allelic variants alter the function of ATM by dominant interference in patients with breast cancer. Proc Natl Acad Sci USA 2002, 99:925-930. 4. Concannon P: ATM heterozygosity and cancer risk. Nat Genet 2002, 32:89-90. 5. Chenevix-Trench G, Spurdle AB, Gatei M, Kelly H, Marsh A, Chen X, Donn K, et al.: Dominant negative ATM mutations in breast cancer families.