Identification of Novel Secreted Molecules Prostate Cancer.

摘要

We have developed an approach to isolate new tumor markers of prostate cancer. In order to identify genes encoding secrete protein, we have modified the signal sequence trap technique, using the SUC 2 gene encoding a secrete protein of yeast. Only the yeast which have been transformed with cDNAs containing secretory signal sequences ca row into colonies on the plates which contain sucrose as the only source of sugar. Early difficulties identifying positive clones with our initial vector system were problematic; we obtained a new vector system to reduce the possibility of enzymatically inactive fusion invertase and enhance the sensitivity of this signal trap system which allowed us to obtain positive clones. We successfully constructed and subtracted a prostate specific cDNA library We, however, found the at this technique gave too many false-positive and false-negative results. Therefore, We turned using another molecular biology technique RDA, and we were fortunate to find TMEFF2. It is gene that we have discovered to be highly expressed in prostate cancers and to be under androgen control. It is highly expressed in AD but not Al prostate cancer cells. Forced expression of this protein markedly decreases growth of prostate cancer cell oth in vitro and in nude mice. In addition, other investigators have suggested TMEFF2 may be a tumor suppresso ene in bladder and colon cancers. Thus, loss of expression of this gene may be associated with progression t ndrogen independence. TMEFF2 could be a target for therapeutic manipulation of this disease and may be used a tumor marker for early diagnosis of prostate cancer because it is a secreted protein. will continue to pursue th election of positive clones, make RNA ot blots from various tissues to establish tissue specificity of the cDNA an erform homology searches to determine if we have found a novel gene.