Loss of heterozygosity on 7q31 occurs early during breast tumorigenesis

✍ Scribed by Marie-Hélène Champème; Ivan Bièche; Michèle Beuzelin; Rosette Lidereau

• Book ID: 102222043
• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 265 KB
• Volume: 12
• Category: Article
• ISSN: 1045-2257
• DOI: 10.1002/gcc.2870120411

✦ Synopsis

Although human breast tumorigenesis is associated with the accumulation of mutations both in oncogenes and in tumor suppressor genes, the identity of the genetic alterations that are critical in the early stages of the breast tumorigenic process remains obscure. A high frequency (27-41%) of loss of heterozygosity (LOH) occurrence has been shown at the MET locus on chromosome band 7q31 and this specific alteration is associated with poorer survival. Here, we report that restriction fragment length polymorphism (RFLP) analysis on 22 I informative (heterozygous) primary breast tumors and 57 informative relapses ( I 3 local recurrences and 44 distant metastases) revealed a similar frequency of 7q3 I LOH as tumors progress from primary cancer to relapse, in marked contrast to other changes such as I I p 15.5 LOH. This finding suggests that inactivation of a putative tumor suppressor gene located in 7q31 is a very early event in breast tumorigenesis. Our results also show that metastatic potential is an induced phenomenon that occurs at a relatively early stage, rather than a marker of tumor progression.