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Intrahepatic cholangiocarcinoma (iCCA) is a highly aggressive cancer with marked resistance to chemotherapeutics without therapies. The tumour microenvironment of iCCA is enriched of Cancer-Stem-Cells expressing Epithelial-to-Mesenchymal Transition (EMT) traits, being these features associated with aggressiveness and drug resistance. Treatment with the anti-diabetic drug Metformin, has been recently associated with reduced incidence of iCCA. We aimed to evaluate the anti-cancerogenic effects of Metformin in vitro and in vivo on primary cultures of human iCCA. Our results showed that Metformin inhibited cell proliferation and induced dose- and time-dependent apoptosis of iCCA. The migration and invasion of iCCA cells in an extracellular bio-matrix was also significantly reduced upon treatments. Metformin increased the AMPK and FOXO3 and induced phosphorylation of activating FOXO3 in iCCA cells. After 12 days of treatment, a marked decrease of mesenchymal and EMT genes and an increase of epithelial genes were observed. After 2 months of treatment, in order to simulate chronic administration, Cytokeratin-19 positive cells constituted the majority of cell cultures paralleled by decreased Vimentin protein expression. Subcutaneous injection of iCCA cells previously treated with Metformin, in Balb/c-nude mice failed to induce tumour development. In conclusion, Metformin reverts the mesenchymal and EMT traits in iCCA by activating AMPK-FOXO3 related pathways suggesting it might have therapeutic implications.

Cholangiocarcinoma (CCA) and its subtypes (mucin- and mixed-CCA) arise from the neoplastic transformation of cholangiocytes, the epithelial cells lining the biliary tree. CCA has a high mortality rate owing to its aggressiveness, late diagnosis and high resistance to radiotherapy and chemotherapeutics. We have demonstrated that CCA is enriched for cancer stem cells which express epithelial to mesenchymal transition (EMT) traits, with these features being associated with aggressiveness and drug resistance. TGF-β signaling is upregulated in CCA and involved in EMT. We have recently established primary cell cultures from human mucin- and mixed-intrahepatic CCA. In human CCA primary cultures with different levels of EMT trait expression, we evaluated the anticancer effects of: (i) CX-4945, a casein kinase-2 (CK2) inhibitor that blocks TGF-β1-induced EMT; and (ii) LY2157299, a TGF-β receptor I kinase inhibitor. We tested primary cell lines expressing EMT trait markers (vimentin, N-cadherin and nuclear catenin) but negative for epithelial markers, and cell lines expressing epithelial markers (CK19-positive) in association with EMT traits. Cell viability was evaluated by MTS assays, apoptosis by Annexin V FITC and cell migration by wound-healing assay., Results: at a dose of 10 μM, CX4945 significantly decreased cell viability of primary human cell cultures from both mucin and mixed CCA, whereas in CK19-positive cell cultures, the effect of CX4945 on cell viability required higher concentrations (>30μM). At the same concentrations, CX4945 also induced apoptosis (3- fold increase vs controls) which correlated with the expression level of CK2 in the different CCA cell lines (mucin- and mixed-CCA). Indeed, no apoptotic effects were observed in CK19-positive cells expressing lower CK2 levels. The effects of CX4945 on viability and apoptosis were associated with an increased number of γ-H2ax (biomarker for DNA double-strand breaks) foci, suggesting the active role of CK2 as a repair mechanism in CCAs. LY2157299 failed to influence cell proliferation or apoptosis but significantly inhibited cell migration. At a 50 μM concentration, in fact, LY2157299 significantly impaired (at 24, 48 and 120 hrs) the wound-healing of primary cell cultures from both mucin-and mixed-CCA. In conclusion, we demonstrated that CX4945 and LY2157299 exert relevant but distinct anticancer effects against human CCA cells, with CX4945 acting on cell viability and apoptosis, and LY2157299 impairing cell migration. These results suggest that targeting the TGF-β signaling with a combination of CX-4945 and LY2157299 could have potential benefits in the treatment of human CCA.

Importance: The prognostic value of lymph node (LN) assessment after liver resection for hilar cholangiocarcinoma (HC) is still controversial, and the number of LNs required to be removed to obtain adequate staging is not well defined., Objectives: To evaluate the LN status in patients after liver resection for HC and to clarify which prognostic factor (the number of positive LNs or the LN ratio [LNR]) was most accurate for staging and what minimum number of retrieved LNs was required for adequate staging., Design, Setting, and Participants: Retrospective multicenter study of patients who underwent resection for HC between January 1, 1992, and December 31, 2007, at 8 hepatobiliary Italian centers. The last follow-up was assessed in July 2014., Main Outcome and Measures: Differences in overall survival (OS) according to the LN status were analyzed. The OS results were defined as actual because all included patients completed a 5-year follow-up., Results: One-hundred seventy-five patients with 1133 retrieved LNs were analyzed. The mean (SD) age of the cohort was 63 (10) years, and 42.9% (75 of 175) were female. The median number of LNs examined per patient was 6.5. Forty percent (70 of 175) had LN metastasis. An LNR exceeding 0.20 was associated with significantly lower 5-year OS than an LNR of 0.20 or less (10.6% vs 24.4%; odds ratio, 2.434; 95% CI, 1.020-5.810; P = .04). On multivariable analysis, the LNR was the only independent prognostic factor for OS but was influenced by the total number of retrieved LNs. The LNR was greater than 0.20 in all patients (30 of 30) with 1 to 4 retrieved LNs and in 52.5% (21 of 40) of patients with at least 5 retrieved LNs. Five-year OS in patients with 1 to 5 retrieved LNs was significantly lower than that in those with 6 to 7 retrieved LNs and those with at least 8 retrieved LNs (34.2%, 64.5%, and 62.7%, respectively; P = .047). Five-year OS did not significantly improve when the number of retrieved LNs was greater than 6. These results were confirmed in a receiver operating characteristic curve analysis performed among N0R0 patients, in whom 5 retrieved LNs was the most accurate cutoff to predict 5-year actual OS (area under the curve, 0.624; P = .004)., Conclusions and Relevance: An LNR exceeding 0.20 was the only independent prognostic factor for OS in N1 patients after liver resection for HC. However, the LNR was influenced by the total number of retrieved LNs, and removal of more than 5 LNs was the minimum number of LNs required for adequate staging.