Induction of scattering and cellular invasion by trefoil peptides in src‐ and RhoA‐transformed kidney and colonic epithelial cells

Abstract

Trefoil factors (TFFs) are protease-resistant peptides that promote epithelial cell migration and mucosal restitution during inflammatory conditions and wound healing in the gastrointestinal tract. To date, the molecular mechanism of TFFs action and their possible role in tumor progression are unclear. In the present study, we observed that premalignant human colonic PC/AA/C1 and canine kidney MDCK epithelial cells are not competent to invade collagen gels in response to exogenously added TFFs (pS2, spasmolytic polypeptide, and intestinal trefoil factor). In contrast, activated src and RhoA exert permissive induction of invasion by the TFFs that produce similar parallel dose-response curves in src-transformed MDCKts.src and PCmsrc cells (EC50=20-40 nM). Cell scattering is also induced by TFFs in MDCKts.src cells. Stable expression of the pS2 cDNA promotes constitutive invasiveness in MDCKts.src-pS2 cells and human colonic HCT8/S11-pS2 cells established from a sporadic tumor. Furthermore, we found that TFF-mediated cellular invasion is dependent of several signaling pathways implicated in cell transformation and survival, including phosphoinositide PI3'-kinase, phospholipase C, protein kinase C, and the rapamycin target TOR. Constitutive and intense expression of pS2 was revealed by Western blot analyses and immunohistochemistry in human colorectal tumors and their adjacent control mucosa during the neoplastic progression, from the adenoma to the liver metastases. Our studies indicated that TFFs can be involved in cell scattering and tumor invasion via autocrine loops and may serve as potential targets in the control of colon cancer progression.

Induction of the adenoma-carcinoma progression and Cdc25A-B phosphatases by the trefoil factor TFF1 in human colon epithelial cells

“…This immunohistochemical analysis clearly illustrates that TFF1 is progressively induced at the transitions between normal mucosa and adenomas. In agreement with previous studies on sporadic colon cancers (Shousha et al, 1993;Emami et al, 2001), TFF1 staining remains persistent during further progression to aggressive carcinomas (Figure 1d and f). Thus, our data support the idea that TFF1 protein induction and persistence in transformed colon epithelial cells may contribute to the early and late stages of the neoplastic progression.…”

“…Interestingly, forced expression of TFF1 in PC cells is associated with the induction of the invasive phenotype ( Figure 2a, left panel). Similar response was observed after transfer of the TFF1 expression vector in parental MDCK epithelial cells (not shown), srctransformed MDCKts.src kidney cancer cells (Figure 2a,right panel), and HCT8/S11 colon cancer cells (Emami et al, 2001). These invasive responses observed in PC-TFF1 and MDCKts.src-TFF1 cells are blocked by pharmacological inhibitors targeting several oncogenic pathways implicated in cell motility, invasion and survival, including Rho GTPases (C3T, 3 mg/ml), Rho-kinase (Y27632, 10 mM), PI3 0 -kinase (WORT, 10 nM), PLCb (U73122, 1 mM), and COX-2 (NS398, 25 mM).…”

“…The transforming functions of TFFs in the digestive tract and other solid tumors are supported by their positive actions on tumor cell invasion, angiogenesis and survival (Emami et al, 2001;Bossenmeyer-Pourie et al, 2002;Rodrigues et al, 2003a, b). To our knowledge, the status and biological significance of TFF1 at the adenoma and carcinoma transitions in the intestine has not been elucidated.…”

“…Recent advances in TFF research indicate their implication in protein folding, intermolecular associations, TFF1 transforming functions and Cdc25 phosphatases S Rodrigues et al signal transduction and transcription of target genes (Tomasetto et al, 2000;Emami et al, 2001;Torres et al, 2002). For example, we have recently demonstrated that TFF3 initiated STAT-3 signalling and cellular invasion through STAT-3-dependent signalling pathways in HCT8/S11 cells (Rivat et al, 2005).…”

“…In contrast, TFF1 is absent in normal colon but is induced at high levels in Crohn disease and colorectal cancers (Emami et al, 2004). Recent studies incriminate TFF1 and other TFFs in the neoplastic progression of the digestive system, according to their scattering, proinvasive and proangiogenic activities in vitro and in vivo (Emami et al, 2001;Rodrigues et al, 2001Rodrigues et al, , 2003bRivat et al, 2005). All TFF members are implicated in cancer cell survival, suggesting that they participate to the aggressive behavior and metastatic potential of colon cancer cells (Taupin et al, 2000;BossenmeyerPourie et al, 2002;Yio et al, 2005).…”