The long-term objective of this proposal is to elucidate the role of Csk-homologous kinase (CHK) in the breast cancer-related ErbB-2 and Src signaling pathways.
The specific aims of this study are to determine 1) the effect of CHK on modification, activation, and function of the ErbB-2 tyrosine kinase receptor cytoplasmic active domain, 2) the effect of CHK on ErbB-2 modification of i) downstream signaling pathway participants; ii) interactions of ErbB-2 with the Src tyrosine kinase; iii) ErbB-2 activation of the ERK-1 and SAPK signaling pathways, and 3) comparative functional analysis of CHK isolated from breast cancer cells/tissues with that isolated from brain and hematopoietic tissues. The studies for specific aims 1 and 2 will utilize recombinant vaccinia virus expression of CHK in 1) NIH3T3 cells which stably express the ErbB-2 cytoplasmic active domain in ligand-dependent or constitutively active forms in the absence of other ErbB-2 pathway participants, and 2) MCF-7 cells, derived from a metastatic breast adenocarcinoma, which endogenously express ErbB-2 and are functional for the ErbB-2 signaling pathway.
Specific aim 3 will be accomplished by kinase assay (with known CHK substrates) of CHK-specific immunoprecipitates. Immunoprecipitates of endogenously expressed CHK from the T47D ductal breast carcinoma cell line, CHK-positive breast tumor tissues, brain, and hematopoietic cells will be compared for kinase activity to determine if CHK endogenously expressed in some breast cancers is deficient in kinase activity. The elucidation of the functional role of CHK in breast cancer-specific signal transduction will advance the current understanding of oncogenic signal transduction mechanisms.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
5F32CA076772-03
Application #
2872001
Study Section
Special Emphasis Panel (ZRG2-SSS-1 (02))
Program Officer
Lohrey, Nancy
Project Start
1999-02-01
Project End
Budget Start
1999-02-01
Budget End
2000-01-31
Support Year
3
Fiscal Year
1999
Total Cost
Indirect Cost
Name
Fox Chase Cancer Center
Department
Type
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19111
Avraham, Hava; Avraham, Shalom; Zagozdzon, Radoslaw (2004) Use of antisense oligonucleotide technology to investigate signaling pathways in megakaryocytes. Methods Mol Biol 273:397-406
McShan, Gina D; Zagozdzon, Radoslaw; Park, Shin-Young et al. (2002) Csk homologous kinase associates with RAFTK/Pyk2 in breast cancer cells and negatively regulates its activation and breast cancer cell migration. Int J Oncol 21:197-205