Background & Aims: Expression of mucin MUC2, the structural component of the colonic mucus layer, is lowered in inflammatory bowel disease. Our aim was to obtain insight in the role of Muc2 in epithelial protection. Methods: Muc2 knockout (Muc2^−/−) and Muc2 heterozygous (Muc2^+/−) mice were characterized and challenged by a colitis-inducing agent, dextran sulfate sodium (DSS). We monitored clinical symptoms, intestinal morphology, and differences in intestine-specific protein and messenger RNA levels. Results: The Muc2^−/− mice showed clinical signs of colitis (as of 5 weeks), aggravating as the mice aged. Microscopic analysis of the colon of Muc2^−/− mice showed mucosal thickening, increased proliferation, and superficial erosions. Colonic goblet cells in the Muc2^−/− mice were negative for Muc2, but trefoil factor 3 was still detectable. In Muc2^−/− mice, transient de novo expression of Muc6 messenger RNA was observed in the distal colon. On day 2 of DSS treatment, the histologic damage was more severe in Muc2^+/− versus wild-type (Muc2^+/+) mice, but the disease activity index was not yet different. By day 7, the disease activity index and histologic score were significantly elevated in Muc2^+/− versus Muc2^+/+ mice. The disease activity index of the Muc2^−/− mice was higher (versus both Muc2^+/+ and Muc2^+/− mice) throughout DSS treatment. The histologic damage in the DSS-treated Muc2^−/− mice was different compared with Muc2^+/+ and Muc2^+/− mice, with many crypt abscesses instead of mucosal ulcerations. Conclusions: This study shows that Muc2 deficiency leads to inflammation of the colon and contributes to the onset and perpetuation of experimental colitis.

SCFAs (short-chain fatty acids), fermentation products of bacteria, influence epithelial-specific gene expression. We hypothesize that SCFAs affect goblet-cell-specific mucin MUC2 expression and thereby alter epithelial protection. In the present study, our aim was to investigate the mechanisms that regulate butyrate-mediated effects on MUC2 synthesis. Human goblet cell-like LS174T cells were treated with SCFAs, after which MUC2 mRNA levels and stability, and MUC2 protein expression were analysed. SCFA-responsive regions and cis-elements within the MUC2 promoter were identified by transfection and gel-shift assays. The effects of butyrate on histone H3/H4 status at the MUC2 promoter were established by chromatin immunoprecipitation. Butyrate (at 1 mM), as well as propionate, induced an increase in MUC2 mRNA levels. MUC2 mRNA levels returned to basal levels after incubation with 5–15 mM butyrate. Interestingly, this decrease was not due to loss of RNA stability. In contrast, at concentrations of 5–15 mM propionate, MUC2 mRNA levels remained increased. Promoter-regulation studies revealed an active butyrate-responsive region at −947/−371 within the MUC2 promoter. In this region we identified an active AP1 (c-Fos/c-Jun) cis-element at −818/−808 that mediates butyrate-induced activation of the promoter. Finally, MUC2 regulation by butyrate at 10–15 mM was associated with increased acetylation of histone H3 and H4 and methylation of H3 at the MUC2 promoter. In conclusion, 1 mM butyrate and 1–15 mM propionate increase MUC2 expression. The effects of butyrate on MUC2 mRNA are mediated via AP-1 and acetylation/methylation of histones at the MUC2 promoter.

BACKGROUND: Despite increasingly radical surgery for esophageal carcinoma, a large number of patients still experience recurrent disease soon after operation. The current study was undertaken to evaluate the pattern of recurrence after curative esophagectomy for cancer of the thoracic esophagus and to identify factors predictive of recurrent disease.METHODS: A total of 439 consecutive patients discharged from the authors' institution following R0 resection between January 1982 and July 2002 were followed for evidence of recurrence over a mean interval of 37.3 (range, 1–207) months.RESULTS: Overall 1‐, 3‐ and 5‐years survival rates were 91%, 54%, and 41%, respectively. Some 230 patients (52.4%) developed proven recurrence, of whom 24 were alive and 206 were dead at the time of writing. The median time to recurrence was 12.0 (range, 6–96) months, with a median survival thereafter of 7.0 (range, 0–83) months. The pattern of recurrence was local in 12.1%, regional in 20.5% (cervical 3.6%, mediastinal 14.8%, and abdominal 2.1%), and distant in 19.8%, respectively. The overall pattern of dissemination was significantly different according to the histologic subtype (P = 0.021). One hundred five (45.7%) of all recurrences occurred within 12 months of surgery, with local, regional, and distant recurrence occurring at a median of 14.0 (range, 6–77), 13.5 (range, 6–73), and 11.0 (range, 6–96) months, respectively; A factor predictive of recurrent disease was histologic tumor depth invasion (P = 0.001).CONCLUSIONS: Depth of tumor invasion should be used to identify patients who will have recurrence within 12 months of operation, so that these patients may be either entered into trials of multimodality treatment or offered nonsurgical palliation. Cancer 2003;97:1616–23. © 2003 American Cancer Society.DOI 10.1002/cncr.11228

Purpose: Metastasis and drug resistance are the major limitations in the survival and management of patients with cancer. This study aimed to identify the mechanisms underlying HT29 colon cancer cell chemoresistance acquired after sequential exposure to 5-fluorouracil (5FU), a classical anticancer drug for treatment of epithelial solid tumors. We examined its clinical relevance in a cohort of patients with colon cancer with liver metastases after 5FU-based neoadjuvant chemotherapy and surgery. Results: We show that a clonal 5F31 cell population, resistant to 1 μmol/L 5FU, express a typical cancer stem cell–like phenotype and enter into a reversible quiescent G₀ state upon reexposure to higher 5FU concentrations. These quiescent cells overexpressed the tyrosine kinase c-Yes that became activated and membrane-associated upon 5FU exposure. This enhanced signaling pathway induced the dissociation of the Yes/YAP (Yes-associated protein) molecular complex and depleted nuclear YAP levels. Consistently, YES1 silencing decreased nuclear YAP accumulation and induced cellular quiescence in 5F31 cells cultured in 5FU-free medium. Importantly, YES1 and YAP transcript levels were higher in liver metastases of patients with colon cancer after 5FU-based neoadjuvant chemotherapy. Moreover, the YES1 and YAP transcript levels positively correlated with colon cancer relapse and shorter patient survival (P < 0.05 and P < 0.025, respectively). Conclusions: We identified c-Yes and YAP as potential molecular targets to eradicate quiescent cancer cells and dormant micrometastases during 5FU chemotherapy and resistance and as predictive survival markers for colon cancer. Clin Cancer Res; 20(4); 837–46. ©2013 AACR.

The 11p15 mucin genes (MUC2, MUC5AC, MUC5B and MUC6) possess a cell-specific pattern of expression in normal lung that is altered during carcinogenesis. Growth factors of the epidermal growth factor family are known to target key genes that in turn may affect the homeostasis of lung mucosae. Our aim was to study the regulation of the 11p15 mucin genes both at the promoter and protein levels to assess whether their altered expression may represent a key event during lung carcinogenesis. Studies were performed in the mucoepidermoid NCI-H292 lung cancer cell line. Cell treatment with epidermal growth factor (EGF), transforming growth factor alpha (TGF-alpha), or tumor necrosis factor alpha (TNF-alpha) resulted in a dramatic increase of MUC2 and MUC5AC mRNAs levels, promoter activity, and apomucin expression, whereas those of MUC5B and MUC6 were unchanged. pGL3 deletion mutants of MUC2, MUC5AC, and MUC5B promoters were constructed and used in transient transfection assays to characterize EGF- and TGF-alpha-responsive regulatory regions within the promoters. They were located in the -2627/-2097 and -202/-1 regions of MUC2 and MUC5AC promoters, respectively. Finally, we demonstrate that transcription factor Sp1 not only binds and activates MUC2 and MUC5AC promoters but also participates to their EGF- and TGF-alpha-mediated up-regulation. We also show that Sp3 is a strong inhibitor of 11p15 mucin gene transcription. In conclusion, MUC2 and MUC5AC are two target genes of EGFR ligands in lung cancer cells, and up-regulation of these two genes goes through concomitant activation of the EGFR/Ras/Raf/Extracellular Signal-regulated Kinase-signaling pathway and Sp1 binding to their promoters.