Identification of a Soluble Factor that Induces Cell Death and Growth Inhibition in Prostate Carcinoma Cells

摘要

This project is to identify an unknown soluble factor, PCIF, which has prostate tumor suppressive potential. We proposed three aims in this grant, which are to identify PCIF, to determine the efficacy of recombinant PCIF on prostate carcinoma cells, and to analyze expression profiles of PCIF in normal and cancerous prostate tissues. During the third year, We have analyzed seven out of eight PCIF candidates, which were identified in year 2, by producing recombinant proteins and testing them in a cell-based assay using LNCaP. None of these candidates exhibited PCIF activity as a recombinant protein when tested singly or in combination with each other. We still need to analyze one candidate. In the meantime, we continued optimization of PCIF purification using the techniques of liquid chromatography and increased the purity of PCIF fraction. We now can produce PCIF fractions that contain less heterogeneous protein composition than previous purification fractions. These fractions are currently being analyzed by mass spectrometry to identify their protein composition. In the extended period (until July 2010), we expect that we will decisively obtain the identity of PCIF and determine the tumor suppressive potential of its recombinant protein on prostate cancer cell lines in culture.