Bachelier Richard, Vincent Anne, Mathevet Patrice, Magdinier Frédérique, Lenoir Gilbert M, Frappart Lucien
Laboratoire de génétique, UMR 5641 CNRS, Université Claude Bernard Lyon I, Faculté de Médecine, 8 avenue Rockefeller, 69373 Lyon cedex 08, France.
Virchows Arch. 2002 Mar;440(3):261-6. doi: 10.1007/s004280100500. Epub 2001 Sep 22.
We have investigated the effects of the expression of wild-type and mutant Brca1 alleles on the murine mammary gland morphogenesis and carcinogenesis. Primary cultures of mammary cells from BALB/cByJIco mice were infected with recombinant Babe Puro retroviruses expressing lacZ, full-length Brca1, splice variant Brca1-Delta11, or mutant Brca1-W1777Stop alleles. Infected cells were reinjected into the mammary fat pad of a syngeneic virgin mouse whose endogenous epithelium had previously been removed. Four months after reinjection, nulliparous and postlactating mice were checked for the reconstitution of the mammary gland. Stable expression of beta-galactosidase was observed in the ducts formed by epithelial mammary cells infected with Babe Puro/ lacZ retrovirus. Epithelial mammary cells transduced with full-length Brca1 developed normally, whereas those transduced with Brca1-Delta11 or Brca1-W1777Stop formed atypical duct hyperplasia associated with reduced branching. These results suggest that ectopically expressed splice variant Brca1-Delta11 and mutant Brca1-W1777Stop have dominant negative effects.
我们研究了野生型和突变型Brca1等位基因的表达对小鼠乳腺形态发生和致癌作用的影响。用表达lacZ、全长Brca1、剪接变体Brca1-Delta11或突变型Brca1-W1777Stop等位基因的重组Babe Puro逆转录病毒感染来自BALB/cByJIco小鼠的乳腺细胞原代培养物。将感染的细胞重新注射到同基因处女小鼠的乳腺脂肪垫中，该小鼠的内源性上皮细胞先前已被去除。重新注射四个月后，检查未生育和哺乳后的小鼠乳腺的重建情况。在用Babe Puro/lacZ逆转录病毒感染的乳腺上皮细胞形成的导管中观察到β-半乳糖苷酶的稳定表达。用全长Brca1转导的乳腺上皮细胞正常发育，而用Brca1-Delta11或Brca1-W1777Stop转导的细胞形成与分支减少相关的非典型导管增生。这些结果表明，异位表达的剪接变体Brca1-Delta11和突变型Brca1-W1777Stop具有显性负效应。
