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The pathogenesis of colon cancer is not well understood. This common type of cancer is generally believed to occur in a multistep process which involves alterations of various tumor suppressor genes and oncogenes during the progression through benign lesions towards carcinoma. TFF3 is a product of the colonic epithelium and has been implicated in colonic mucosal protection and also in the aggressiveness of colon cancer cells. The aim of this study was to analyze the expression of TFF3 during propagation towards cancer development in the human colon. Colonic tissues representing colitis, adenomatous polyposis, tubulovillous adenoma, and mucoid/adeno-carcinomas were processed for immunohistochemistry using an antibody specific for human TFF3. The results were correlated with those of PCNA-labeling, quantified, and compared with those of control tissues obtained from the safe margin of macroscopically normal colonic mucosa of patients with colon cancer. The data showed marked down-regulation of TFF3 expression in adenomatous polyposis, then TFF3 expression returns to about control level during adenoma and remains high during mucoidand adeno-carcinomas. Colonic tissues with highly invasive cancer cells were characterized by statistically significant down-regulation of TFF3 expression. The changes observed in expression of TFF3 showed an inverse correlation with cell proliferation and suggest that it might play a protective role against colon carcinogenesis. Key words

Circulating proteinic biomarkers are secreted by tumor cells or by their environmental cells and they have a variable specificity. In case of breast cancer, carcino-embryonic antigen (CEA) was for a long time the only circulating biomarker used. Nowadays, the most useful biomarkers measure circulating levels of fragments of MUC1-polymorphic epithelial mucin (MUC1-PEM): cancer antigen (CA) 15.3, mucin-like carcinoma-associated antigen (MCA), CA 27-29, CA 549... They are useful for general disease follow-up. Other circulating markers belonging to keratins (tissue polypeptide antigen, TPA, TPS or Cyfra 21.1) are correlated with proliferative activity of breast tumors. More recently, the measure of the c-erb B2 circulating part (extra cellular domain, ECD) was proposed as a prognostic biomarker for breast tumors with c-erb B2 overexpression. Moreover, the determination of urinary level of trefoil factor1 (PS2-TFF1) might be useful for the follow-up of hormonodependent breast cancers. The present review describes the clinical interest of these different circulating biomarkers in case of breast cancer, emphasizing their biological characteristics.

International audience; Trefoil Factor 1 (TFF1), the first member of the trefoil factor family, is normally expressed in the stomach mucosa. Ectopic expression is also observed in various human pathological conditions, notably in numerous carcinomas and gastrointestinal acute inflammatory disorders. In vivo experimental data using TFF1-deficient mice highlight the pleiotropic functions of TFF1: (i) it is a gastric tumor suppressor gene involved in gastric ontogenesis and homeostasis; (ii) it protects gut mucosa from aggression; (iii) it participates in folding secreted proteins inside the endoplasmic reticulum. At the cellular level, it limits cell proliferation and apoptosis, and favors cell differentiation. Collectively, these data suggest that TFF1 may provide an alternative pharmacological tool for the prevention and treatment of human gastrointestinal diseases.

The trefoil factor (TFF) family includes three members : TFF1 also called pS2, TFF2 or spasmolytic peptide (SP) and TFF3 or intestinal trefoil factor (ITF). TFFs are associated with mucin-secreting epithelial cells and play a crucial role in mucosal defense and healing. In case of mucosa aggression (due to bacteria, virus or medication), inflammatory diseases and ulcerous pathology, they are involved in epithelium restitution and regeneration. In comparison with the other TFFs, pS2/TFF1 has particular functions. Notably, it acts like a suppressor gene for gastric tumors. Evidence of pS2/TFF1 overexpression has been found in a range of carcinomas (breast, bowel, prostate, pancreas, thyroid, lung...). In breast cancer, pS2/TFF1 overexpression contributes to a favorable prognosis. Moreover, it is a predictive factor of hormonotherapy response.

Several phosphinic pseudo-tripeptides of general formula R-XaaΨ(PO2- CH2)Xaa'-Yaa'-NH2 were synthesized and evaluated for their in vitro activities to inhibit stromelysin-3, gelatinases A and B, membrane type-1 matrix metalloproteinase, collagenases 1 and 2, and matrilysin. With the exception of collagenase-1 and matrilysin, phosphinic pseudo-tripeptides behave as highly potent inhibitors of matrix metalloproteinases, provided they contain in P1' position an unusual long aryl-alkyl substituent. Study of structure-activity relationships regarding the influence of the R and Xaa' substituents in this series may contribute to the design of inhibitors able to block only a few members of the matrix metalloproteinase family.