Purpose: After the advent of targeted therapies for hepatocellular carcinoma (HCC), much work is being done to provide a comprehensive description of the different signaling pathways contributing to cell survival and proliferation in this tumor. Apoptotic signaling mediated by tumor necrosis factorrelated apoptosis-inducing ligand (TRAIL) represents an important mechanism of tumor surveillance, but its importance in the development of HCC is not known. We thus investigated the cellular distribution and the prognostic importance of TRAIL receptors in HCC.Experimental Design: Immunohistochemical staining for TRAIL receptors was evaluated in HCC tissues and in matched surrounding nontumor tissues of 157 HCC patients treated with liver transplantation or partial hepatectomy. Survival was analyzed in 93 patients who underwent partial hepatectomy.Results: The fraction of HCC samples with positive membrane staining for TRAIL receptor 1 (TRAIL-R1) and 2 (TRAIL-R2) was 1.4-and 2.7-fold lower compared with that of hepatocytes from surrounding tissues (P = 0.01). Loss of either TRAIL-R1 or TRAIL-R2, as confirmed by a multivariate analysis, significantly worsened 5-year survival of HCC patients {survival, 27% versus 52% and 15% versus 43%; hazard ratio (HR), 2.3 [95% confidence interval (CI), 1.1-4.4] and 2.4 (95% CI, 1.1-5.2), respectively}. Loss of both TRAIL receptors further decreased survival of patients [HR, 5.72 (95% CI, 2.1-15.5) versus double-negative staining; P = 0.001], indicating an additive effect on survival of TRAIL-R1 and TRAIL-R2.Conclusions: This pilot study suggests that loss of TRAIL receptors is a frequent feature of HCCs and an independent predictor of survival in patients undergoing partial hepatectomy. Future therapeutic protocols are likely to profit from the characterization of their expression and cellular distribution.

BackgroundMost colorectal carcinomas are driven by an activation of the canonical Wnt signalling pathway, which promotes the expression of multiple target genes mediating proliferation inavasion and invasion. Upon activation of the Wnt signalling pathway its key player β-catenin translocates from the cytoplasm to the nucleus and binds to members of the T-cell factor (TCF)/lymphoid enhancer factor (LEF-1) family namely LEF-1 and TCF4 which are central mediators of transcription. In this study we investigated the expression of β-Catenin, LEF1 and TCF4 in colorectal carcinomas and their prognostic significance.MethodsImmunohistochemical analyses of LEF-1, TCF4 and nuclear β-Catenin were done using a tissue microarray with 214 colorectal cancer specimens. The expression patterns were compared with each other and the results were correlated with clinicopathologic variables and overall survival in univariate and multivariate analysis.ResultsLEF-1 expression was found in 56 (26%) and TCF4 expression in 99 (46%) of colorectal carcinomas and both were heterogenously distributed throughout the tumours. Comparing LEF-1, TCF4 and β-catenin expression patterns we found no correlation. In univariate analysis, TCF4 expression turned out to be a negative prognostic factor being associated with shorter overall survival (p = 0.020), whereas LEF-1 expression as well as a LEF-1/TCF4 ratio were positive prognostic factors and correlated with longer overall survival (p = 0.015 respectively p = 0.001). In multivariate analysis, LEF-1 and TCF4 expression were confirmed to be independent predictors of longer respectively shorter overall survival, when considered together with tumour stage, gender and age (risk ratio for LEF-1: 2.66; p = 0.027 risk ratio for TCF4: 2.18; p = 0.014).ConclusionsThis study demonstrates different prognostic values of LEF-1 and TCF4 expression in colorectal cancer patients indicating different regulation of these transcription mediators during tumour progression. Moreover both factors may serve as new potential predictive markers in low stage colon cancer cases in advance.

(2012) Human telomerase reverse transcriptase (hTERT) is a target gene of β-catenin in human colorectal tumors, Cell Cycle, 11:17,[3331][3332][3333][3334][3335][3336][3337][3338]

A mutually compatible vector system was developed for the bench-top fermenter production of mouse and rabbit Fab fragments comprising pASK85-pro-K411B and pASK85Rab-pro-WR13. These vectors provide a mouse- and rabbit-specific cloning site, respectively, the tetA promoter/operator and the proBA operon that complements the Pro biosynthetic deficiency of the Escherichia coli strain JM83 and can serve as an additional selection marker. Fermentation at elevated cell density (OD600 = 2040) of the atrazine-specific mouse Fab fragment K411B using JM83 harboring pASK85-pro-K411B in a 2 L bench-top vessel resulted in a yield of 240 g/L OD600 affinity-purified protein (13.8 mg). In contrast, expression of leporid Fab fragments using pASK85Rab-pro-WR13 was unsuccessful due to the aggregation of rabbit light chains, which probably relates to a general problem of this specific class of immunoglobulins with their additional Cys residues. Coexpression of rabbit Fab fragments together with four periplasmic folding-helper proteins encoded on pTUM4 led to a significantly improved folding efficiency, resulting in a yield of 50 µg/L OD600 affinity-purified rabbit Fab fragment (3.3 mg) from the 2 L bench-top fermenter.

3519^ Background: We investigated the expression of the EGFR ligands amphiregulin (AREG) and epiregulin (EREG) as well as the amplification of the EGFR-gene in tumor specimens of mCRC patients (pts) treated first-line with anti-EGFR targeted cetuximab together with CAPOX or CAPIRI. Expression levels were correlated with overall response rate (ORR), progression free survival (PFS) and overall survival (OS) to determine their relationship with effectiveness in this setting. Methods: A total of 185 mCRC pts were randomized to cetuximab (400mg/m² day 1, followed by 250mg/m² weekly) plus CAPIRI (irinotecan 200mg/m², day 1; capecitabine 800mg/m² twice daily days 1-14, every 3 weeks; 20% dose reduction of both agents for pts older than 65 years) or plus CAPOX (oxaliplatin 130mg/m² day 1; capecitabine 1000mg/m² twice daily days 1-14, every three weeks). The primary study endpoint was ORR. KRAS mutational status did not correlate with treatment outcome. The cut-offs for EGFR-amplification using FISH, AREG and EREG levels determined by RT-qPCR were calculated using ROC analysis for ORR. Results: Within the subgroup of KRAS wildtype tumors, analysis of EREG- and AREG-expression was possible in 99 pts and of EGFR-amplification in 63 pts. Higher AREG levels correlated significantly with higher ORR (83% vs 46%, p=0.006, OR 0.31), longer PFS (9.6mo vs 4.9, p<0.001, HR 0.35) and longer OS (39.9mo vs 17.2mo, p<0.001, HR 0.36). Higher EREG levels showed a significant correlation with ORR (74% vs 47%, p=0.036, OR 0.54), longer PFS (7.9mo vs 4.9mo, p=0.026, HR 0.57) and OS (33.0mo vs 20.2mo, p=0.041, HR 0.57). EGFR-amplification correlated significantly with higher ORR (71% vs 33%, p=0.004, OR 0.49), longer PFS (8.4mo vs 4.6mo, p=0.004, HR 0.50) and longer OS (30.5mo vs 15.2mo, p=0.001, HR 0.44). Conclusions: In the treatment setting of cetuximab combined with CAIPIRI or CAPOX, AREG, EREG and EGFR-amplification predicted treatment efficacy. Within the subgroup of pts with KRAS wildtype tumors, EGFR-FISH and AREG expression have the strongest relationship with treatment efficacy.