Wnt signaling is often constitutively active in colorectal cancer cells. The expression of the intestinal specific transcription factor CDX2 is found to be transiently decreased in invasive cells at the tumor/stroma interface. A recent ChIP-Seq study has indicated that several Wnt signaling-related genes are regulated by CDX2. The aim was to investigate the role of decreased CDX2 level on the expression of APC, AXIN2 and GSK3β in migrating colon cancer cells at the invasive front. CDX2-bound promoter and enhancer regions from APC, AXIN2 and GSK3β were analyzed for gene regulatory activity and the expression pattern of APC and GSK3β at the invasive front was evaluated by immunohistochemical procedures. Transfection of intestinal and non-intestinal cell lines demonstrated that CDX2 activated APC and AXIN2 promoter activities via intestinal cell-specific enhancer elements. Suppressed CDX2 expression was associated with endogenous downregulation of APC and AXIN2 expression in Caco-2 cells but did not affect GSK3β expression. Furthermore, elevated levels of nuclear β-catenin and reduced levels of cytoplasmic APC were correlated to a low CDX2 expression in migrating colon cancer cells in vivo. These results suggest that a low CDX2 level has influence on the Wnt signaling in invasive colon cancer cells possibly promoting cellular migration.

No abstract

Peptide receptor radionuclide therapy (PRRT) is a relatively new mode of internally targeted radiotherapy currently in clinical trials. In PRRT, ionizing radioisotopes conjugated to somatostatin analogues are targeted to neuroendocrine tumors (NETs) via somatostatin receptors. Despite promising clinical results, very little is known about the mechanism of tumor control. By using NCI-H727 cells in an in vivo murine xenograft model of human NETs, we showed that 177Lu-DOTATATE PRRT led to increased infiltration of CD86+ antigen presenting cells into tumor tissue. We also found that following treatment with PRRT, there was significantly increased tumor infiltration by CD49b+/FasL+ NK cells potentially capable of tumor killing. Further investigation into the immunomodulatory effects of PRRT will be essential in improving treatment efficacy.

Purpose. The indication for liver transplantation in malignant liver tumors has been controversial due to disappointing results and shortage of donor organs. The authors evaluated the experience and results of a single center in order to define present indications and selection criteria in hepatobiliary malignancy. Patients and Methods. Retrospective analysis of 212 patients who underwent liver transplantation for malignant tumors between 1972 and 1995: Primary hepatobiliary tumors: hepatocellular carcinoma, n = 124 (with underlying cirrhosis, n = 86; fibrolamellar subtype, n = 8); intrahepatic bile duct (cholangiocellular) carcinoma, n = 24; proximal bile duct carcinoma, n = 29; other uncommon entities (n = 15); secondary liver tumors: neuroendocrine, n = 11, and nonendocrine, n = 9. Results. Survival rates in primary liver cancer were correlated to International Union Against Cancer (UICC) tumor stage. For hepatocellular and proximal bile duct carcinoma significantly better outcome was found in UICC‐tumor stage I and II versus III and IV. No long‐term survival was found after transplantation for intrahepatic bile duct carcinoma, hemangiosarcoma and nonendocrine liver metastases. Comparison of transplant and resected patients with hepatocellular carcinoma stage I and II with underlying cirrhosis showed better survival after transplantation: 1‐, 3‐, 5‐year survival rate of 83.3% versus 76.9%, 75.8% versus 44.0%, 60.6% versus 44.0%, and median survival 96.5 versus 23.2 months. Although this difference was not significant, no patient died from tumor recurrence in the transplant group versus three in the resection group. Discussion and Conclusions. Patients with malignant tumors can be selected for transplantation with predictable likelihood for long‐term survival. According to the present data, liver transplantation can be considered in unresectable UICC‐stage II hepatocellular and proximal bile duct carcinoma, the uncommon entities fibrolamellar carcinoma, epithelioid hemangioendothelioma and hepatoblastoma as well as liver metastases from neuroendocrine tumors. UICC‐stage III and IV hepatocellular carcinoma as well as intrahepatic bile duct carcinoma, hemangiosarcoma and metastases from nonendocrine tumors should be excluded from transplantation alone. For hepatocellular carcinoma, multimodality treatment protocols have had a proven impact on the prevention of early recurrence and prolongation of survival. There is evidence that liver transplantation in still resectable hepatocellular carcinoma with underlying cirrhosis might be more appropriate in order to cure the cancer‐bearing disease.

View related articles View Crossmark data Citing articles: 8 View citing articles DNA methyltransferases expression in normal tissues and various human cancer cell lines, xenografts and tumors.