Characterization of SIRPs in Prostate Cancer Cells
Abstract
Signal regulatory proteins (SIRPs) include SIRPbeta1, which activates cells, and SIRPalpha1, which inhibits the response to several growth factors and which regulates cell adhesion and spreading. We demonstrated by PCR that 3 of 3 prostate cancer cell lines (PC-3, DU-145 and LNCaP) express transcripts for SIRPalphal. We have generated monoclonal antibodies (mAbs) against SIRPs and thereby demonstrated SIRPs on PC-3 and DU- 145 cells. Northern blotting also reveals SIRP transcripts in these lines. By RT-PCR of RNA from PC-3 cells, we have found transcripts only for SIRPalphal, not SIRPbeta1. In support of this, pervanadate treatment of PC-3 cells reveals an association of SIRP with SHP-2 (characteristic of SIRPalpha) but not with DAP12 (characteristic of SIRPbeta). We have overexpressed epitope (FLAG)-tagged SIRPalpha in PC-3 cells to examine the effect on response to growth factors and on cell adhesion/spreading. With IRB approval, we have tested for the expression of SIRPs in fresh-frozen biopsies of prostrate tumors. These studies suggest the expression of SIRPs in prostate tumor cells, but our antibody lacks the sensitivity to be certain. We have made good progress in our Objectives, and we expect to complete all of our objectives by the end of this contract.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 2002
- Accession Number
- ADA405290
Entities
People
- William E. Seaman
Organizations
- Northern California Institute for Research and Education