title: Study of nm23 gene expression in an N-methyl-N-nitrosourea transformed human breast epithelial cell line.
abstract: In the present study we pinpoint the time of nm23 down-regulation during the chemical transformation of the human breast epithelial cell line HBL100. The non-malignant HBL100 was transformed by exposing it to N-methyl-N-nitrosourea (MNU). We subsequently injected the transformed cells (HBL-T-MNU) into nude mice, resulting in tumor growth. With a second passage of these tumors in mice we observed lung and extra-regional node metastases. The expression of nm23 in the non-tumorigenic HBL100 cells was compared to the tumorigenic KBL-T-MNU cells as well as to the metastatic cell line HBL-T2(MNU) derived from the tumor induced by HBL-T-MNU cells. By using immunohistochemistry and Western blot analysis we documented the downregulation of nm23 expression in the tumorigenic HBL-T-MNU and metastatic HBL-T2(MNU) cell lines, as compared to the parental line HBL100. Once downregulated, nm23 expression in this model remains constant during the subsequent progression. These results suggest that nm23 down-regulation may indeed be associated with early neoplastic transformation and is maintained throughout neoplastic progression and metastatic stage.
authors.affiliation: UNIV ILLINOIS,DEPT SURG ONCOL,COLL MED,CHICAGO,IL 60612.
authors.forename: G
authors.initials: G
authors.lastname: Lazzaro
authors.forename: S
authors.initials: S
authors.lastname: Sharpless
authors.forename: W
authors.initials: W
authors.lastname: Qing
authors.forename: R
authors.initials: R
authors.lastname: Mehta
authors.forename: T
authors.initials: T
authors.lastname: Dasgupta