Pim-1 kinase expression during murine mammary development

• Published in: Biochemical and biophysical research communications Vol. 345; no. 3; pp. 989 - 997
• Main Authors: Gapter, Leslie A., Magnuson, Nancy S., Ng, Ka-yun, Hosick, Howard L.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 07.07.2006
• Subjects: 60 APPLIED LIFE SCIENCES; Animals; APOPTOSIS; Breast; Breast - metabolism; CARCINOMAS; Cell Differentiation; Cell Line, Tumor; Cell Proliferation; Cyclin-Dependent Kinase Inhibitor p21 - metabolism; Gene Expression Regulation, Developmental; Gene Expression Regulation, Enzymologic; Growth and development; Humans; IN VITRO; Kinase; LYMPHOKINES; Mammary cell line; MAMMARY GLANDS; Mammary Glands, Animal - embryology; Mammary Glands, Animal - enzymology; Mammary Neoplasms, Animal - embryology; Mammary Neoplasms, Animal - enzymology; MICE; MONOCLINIC LATTICES; P21 CIP/Waf1; Pim-1; PROGESTERONE; Proto-Oncogene Proteins c-pim-1 - biosynthesis; SUBSTRATES; Pim-1; Growth and development; Kinase; P21 CIP/Waf1; Breast; Mammary cell line; Progesterone
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2006.04.110

Pim-1 kinase phosphorylates substrates whose activities are linked to proliferation, survival, differentiation, and apoptosis. Although pim-1 is induced by hormones and cytokines, the hormonal control and contribution of Pim-1 to mammary gland development have not been evaluated. We examined Pim-1 expression in mammary cell lines, investigated whether Pim-1 levels could be altered in breast epithelia by mammogenic hormones, and evaluated Pim-1 expression during mammary development. We found that Pim-1 was elevated in most mammary carcinoma cell lines and progesterone increased Pim-1 protein to some extent in non-tumorigenic mammary epithelia. Pim-1 expression in situ was consistent with the documented profile of progesterone activity in mouse mammary glands. Pim-1 nuclear localization correlated with cytoplasmic distribution for its substrate, p21 CIP/Waf1, and we found that Pim-1 and p21 associate in vitro. Our results suggest that Pim-1 expression may be regulated by progesterone during mammary development and Pim-1 associates with p21 in mammary epithelial cells.