Thus, the extensive GAG modification of APLP2 in pancreatic cancer cells may have a pro-migratory influence. Figure 1 APLP2 expression and post-translational modification are elevated in pancreatic cancer. (A) GAG-modified APLP2, full-length APLP2 and APLP2 C-terminal http://www.selleckchem.com/products/Perifosine.html fragments were found to be highly expressed in several human pancreatic cancer cell lines by western … In addition to APLP2, APP was expressed in each of the pancreatic cancer cell lines (Fig. 1A). The two bands of APP represent immature (bottom) and mature (upper) full-length protein, with the higher molecular mass of the mature form due to glycosylation (47). APP has been shown to promote proliferation of the BxPC3 pancreatic cancer cell line, conferring this activity through the soluble N-terminal fragment (24,48), and soluble APLP2 has been identified in the secretome of another pancreatic cancer cell line, SUIT-2 (49).

Liberation of soluble APP and soluble APLP2 occurs following secretase cleavage of the full-length proteins, simultaneously creating 12�C15 kDa intracellular C-terminal fragments (1,20�C23). We determined the expression of C-terminal fragments for APP and APLP2 in our panel of pancreatic cancer cell lines by western blot analysis. APLP2 C-terminal fragments were present in all cell lines examined, whereas APP C-terminal fragments were only substantially present in the BxPC3 cell line (Fig. 1A). In some cell types, APLP2 or APP C-terminal fragments have been shown to be additionally be cleaved by ��-secretase, generating smaller, 4 kDa C-terminal fragments (1,2,20).

These smaller fragments of APLP2 or APP were not observed in our panel of pancreatic Dacomitinib cancer cell lines, even when samples were electrophoresed on 18% Tris-glycine gels and the film was exposed overnight (data not shown). These data implicate APLP2 as the primary cleavage target of secretases in the majority of pancreatic cancer cells, rather than APP. We therefore pursued the function of APLP2 expression and cleavage in transformed pancreatic cells. Oncogene expression increases the presence of APLP2 and of APLP2 C-terminal fragments Our identification of GAG-modified APLP2 and APLP2 C-terminal fragment expression in pancreatic cancer cell lines did not clarify whether these forms of APLP2 occur only in the transformed state, or if GAG-APLP2 and APLP2 C-terminal fragments are also endogenously present in untransformed pancreatic ductal cells. To address this question, we determined the expression of APLP2 in a series of cell lines generated from the hTERTHPNE cell line, which has been well characterized and used previously in several pancreatic cancer studies (42�C46).