title: Selection of early-occurring mutations dictates hormone-independent progression in mouse mammary tumor lines.
abstract: Mice harboring three mouse mammary tumor virus (MMTV) variants develop pregnancy-dependent (PD) tumors that progress to pregnancy-independent (PI) behavior through successive passages. Herein, we identified 10 predominant insertions in PI transplants from 8 independent tumor lines. These mutations were also detected in small cell populations in the early PD passages. In addition, we identified a new viral insertion upstream of the gene Rspo3, which is overexpressed in three of the eight independent tumor lines and codes for a protein very similar to the recently described protein encoded by Int7. This study suggests that during progression towards hormone independence, clonal expansion of cells with specific mutations might be more relevant than the occurrence of new MMTV insertions.
authors.affiliation: IFIBYNE-CONICET, Facultad de Ciencias Exactas y Naturales, UBA Ciudad Universitaria, Pabellón 2, 2do piso, (1428) Buenos Aires, Argentina.
authors.forename: Albana
authors.initials: A
authors.lastname: Gattelli
authors.forename: María N
authors.initials: MN
authors.lastname: Zimberlin
authors.forename: Roberto P
authors.initials: RP
authors.lastname: Meiss
authors.forename: Lucio H
authors.initials: LH
authors.lastname: Castilla
authors.forename: Edith C
authors.initials: EC
authors.lastname: Kordon
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D008325:Mammary Neoplasms, Experimental / Q000235:genetics* / Q000821:virology*; D008324:Mammary Tumor Virus, Mouse / Q000235:genetics*; D051379:Mice; D009154:Mutation; D011995:Recombination, Genetic; D012192:Retroviridae Infections / Q000821:virology*; D012641:Selection, Genetic; D014412:Tumor Virus Infections / Q000821:virology*