sirolimus and Cholangiocarcinoma

Hepatocellular cancer (HCC), as well as cholangiocellular cancer (CCC), has an extremely poor prognosis due to the extent of tumor at diagnosis and the underlying liver disease. Sirolimus is used in the transplantation setting as an immunosuppressive agent, but it also possesses antiproliferative and antiangiogenic properties. The objective of the study was to evaluate the effect of sirolimus on HCC and CCC.. In a prospective single-arm protocol, the tumor response to sirolimus as the primary endpoint was studied in 21 patients with advanced HCC and nine with CCC. Sirolimus was administered once daily by mouth, with the dose adjusted to a serum trough level between 4 and 15 mug/ml. Tumor response was evaluated by computed tomography (CT) or magnetic resonance imaging (MRI), according to the Response Evaluation Criteria in Solid Tumors (RECIST), every third month. Secondary measures were overall survival, time to tumor progression, tumor markers, and side effects.. Of the patients with HCC, one had partial remission (PR) and fi ve patients had stable disease (SD) at 3 months. Of the patients with CCC, three had SD. The median survival for patients with HCC was 6.5 months (range, 0.2-36 months) and that for patients with CCC was 7 months (range, 2.6-35 months).. Treatment of HCC and CCC with sirolimus can induce temporary PD or SD. This pilot study indicates that sirolimus might be a promising drug for this treatment, but further clinical studies elucidating the biological effects are advocated.

Topics: Adult; Aged; Antibiotics, Antineoplastic; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Carcinoma, Hepatocellular; Cholangiocarcinoma; Female; Humans; Liver Neoplasms; Male; Middle Aged; Phosphoinositide-3 Kinase Inhibitors; Protein Kinases; Sirolimus; TOR Serine-Threonine Kinases

Topics: Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Survival; Cholangiocarcinoma; Humans; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases

The incidence of primary liver tumors, hepatocellular carcinoma (HCC), intrahepatic cholangiocellular carcinoma (ICC), and combined HCC/ICC (cHCC/CC) is increasing. For ICC, targeted therapy exists only for a small subpopulation of patients, while for HCC, Sorafenib and Lenvatinib are in use. Diagnosis of cHCC/CC is a great challenge and its incidence is underestimated, bearing the risk of unintended non-treatment of ICC. Here, we investigated effects of targeted inhibitors on human ICC cell lines (HUH28, RBE, SSP25), in comparison to extrahepatic (E)CC lines (EGI1, CCC5, TFK1), and HCC/hepatoblastoma cell lines (HEP3B, HUH7, HEPG2). Cells were challenged with: AKT inhibitor MK-2206; multikinase inhibitors Sorafenib, Lenvatinib and Dasatinib; PI3-kinase inhibitors BKM-120, Wortmannin, LY294002, and CAL-101; and mTOR inhibitor Rapamycin. Dosage of the substances was based on the large number of published data of recent years. Proliferation was analyzed daily for four days. All cell lines were highly responsive to MK-2206. Thereby, MK-2206 reduced expression of phospho(p)-AKT in all ICC, ECC, and HCC lines, which mostly corresponded to reduction of p-mTOR, whereas p-ERK1/2 was upregulated in many cases. Lenvatinib showed inhibitory effects on the two HCC cell lines, but not on HEPG2, ICCs and ECCs. Sorafenib inhibited proliferation of all cells, except the ECC line CCC5. However, at reduced dosage, we observed increased cell numbers in some ICC experiments. Dasatinib was highly effective especially in ICC cell lines. Inhibitory effects were observed with all four PI3-kinase inhibitors. However, cell type-specific differences were also evident here. Rapamycin was most effective in the two HCC cell lines. Our studies show that the nine inhibitors differentially target ICC, ECC, and HCC/hepatoblastoma lines. Caution should be taken with Lenvatinib and Sorafenib administration in patients with cHCC/CC as the drugs may have no effects on, or might even stimulate, ICC.

Topics: Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Carcinoma, Hepatocellular; Cholangiocarcinoma; Dasatinib; Hepatoblastoma; Humans; Liver Neoplasms; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Sirolimus; Sorafenib

The loss of contact inhibition is a hallmark of a wide range of human cancer cells. Yet, the precise mechanism behind this process is not fully understood. c‑Myc plays a pivotal role in carcinogenesis, but its involvement in regulating contact inhibition has not been explored to date. Here, we report that c‑Myc plays an important role in abrogating contact inhibition in human cholangiocarcinoma (CCA) cells. Our data show that the protein level of c‑Myc obviously decreased in contact-inhibited normal biliary epithelial cells. However, CCA cells sustain high protein levels of c‑Myc and keep strong proliferation ability in confluent conditions. Importantly, the suppression of c‑Myc by inhibitor or siRNA induced G0/G1 phase cell cycle arrest in confluent CCA cells. We demonstrate that the inhibition of c‑Myc suppressed the activity of mammalian target of rapamycin (mTOR) in confluent CCA cells, and mTOR inhibition induced G0/G1 phase cell cycle arrest in confluent CCA cells. In confluent CCA cells, the activity of Merlin is downregulated, and Yes-associated protein (YAP) sustains high levels of activity. Furthermore, YAP inhibition not only induced G0/G1 phase cell cycle arrest, but also decreased c‑Myc expression in confluent CCA cells. These results indicate that Merlin/YAP/c‑Myc/mTOR signaling axis promotes human CCA cell proliferation by overriding contact inhibition. We propose that overriding c‑Myc‑mediated contact inhibition is implicated in the development of CCA.

Topics: Carcinogenesis; Cell Cycle Checkpoints; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Cholangiocarcinoma; Contact Inhibition; Gene Expression Regulation, Neoplastic; Humans; Neurofibromin 2; Nuclear Proteins; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Transcription Factors

Less is known about the roles of eukaryotic initiation factor alpha (eIF2α) in cholangiocarcinoma (CCA). Here, we report that eIF2α inhibitor salubrinal inhibits the proliferation of human CCA cells. Clinical application of mammalian target of rapamycin (mTOR) inhibitors only has moderate antitumor efficacy. Therefore, combination approaches may be required for effective clinical use of mTOR inhibitors. Here, we investigated the efficacy of the combination of salubrinal and rapamycin in the treatment of CCA. Our data demonstrate a synergistic antitumor effect of the combination of salubrinal and rapamycin against CCA cells. Rapamycin significantly inhibits the proliferation of CCA cells. However, rapamycin initiates a negative feedback activation of Akt. Inhibition of Akt by salubrinal potentiates the efficacy of rapamycin both in vitro and in vivo. Additionally, rapamycin treatment results in the up-regulation of Bcl-xL in a xenograft mouse model. It is notable that salubrinal inhibits rapamycin-induced Bcl-xL up-regulation in vivo. Taken together, our data suggest that salubrinal and rapamycin combination might be a new and effective strategy for the treatment of CCA.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; bcl-X Protein; Bile Duct Neoplasms; Cell Line, Tumor; Cell Proliferation; Cholangiocarcinoma; Cinnamates; Drug Synergism; Eukaryotic Initiation Factor-2; Humans; Male; Mice, Nude; Phosphorylation; Proto-Oncogene Proteins c-akt; Signal Transduction; Sirolimus; Thiourea; Time Factors; TOR Serine-Threonine Kinases; Tumor Burden; Xenograft Model Antitumor Assays

After liver transplantation for cholangiocarcinoma (CCC), patients have a poor prognosis without use of specific therapeutic strategies. Accordingly, recipients with incidental CCC might have the highest risk of recurrent disease; however, sparse data on the long-term outcome of unselected patients with incidental CCC have been published. The aim of this study was to evaluate the post-transplantation outcomes of patients with incidental CCC with special focus on tumor localization.. There were 11 primary liver transplantations in patients with incidental CCC of 1310 liver transplantation procedures performed between December 1994 and August 2013. All patients with incidental CCC received a chemotherapy regiment including gemcitabine/5 fluorouracil, doxorubicin, and mitomycin. The patients were switched from calcineurin inhibitors to mammalian target of rapamycin inhibitor-based immunosuppression shortly after CCC diagnosis.. Intra- and extrahepatic tumors were found in 6 and 5 patients, respectively. At median follow-up examination of 26.3 months there were 8 CCC recurrences and 7 patient deaths. Overall survival after liver transplantation for incidental CCC was 88.9% at 1 year, 44.4% at 2 years, and 14.8% at 3 years. The corresponding rates of recurrence-free survival were 45.7%, 45.7%, and 0.0%, respectively. Post-transplantation CCC recurrences were universal with 0% 3-year recurrence-free survival both in patients with intra- and extrahepatic tumors (P = .475).. Incidental CCC in liver transplantation is associated with poor outcomes irrespective of tumor localization. Introduction of new adjuvant multimodal treatment concepts is necessary to improve the prognosis for this subgroup of patients.

Topics: Adult; Antineoplastic Combined Chemotherapy Protocols; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Calcineurin Inhibitors; Cholangiocarcinoma; Combined Modality Therapy; Deoxycytidine; Doxorubicin; Female; Fluorouracil; Gemcitabine; Humans; Immunosuppressive Agents; Incidental Findings; Liver Neoplasms; Liver Transplantation; Male; Middle Aged; Mitomycin; Neoplasm Recurrence, Local; Prognosis; Sirolimus; Survival Analysis; Treatment Outcome

Cholangiocarcinoma (CCA) is a rare, but devastating disease arising from the epithelium of intrahepatic and extrahepatic bile ducts. There are neither effective systemic therapies nor satisfying treatment options for inoperable CCA. Histopathological and biochemical studies of CCA show frequent dysregulation of the phosphatidylinositol 3-kinase/AKT/mammalian target of rapamycin (mTOR) pathway. Therefore, we investigated the efficacy of the mTOR inhibitor RAD001 and the impact of AKT signaling following mTOR inhibition in the treatment of CCA. RAD001 significantly inhibits proliferation of CCA cell lines, however, a concentration-dependent and isoform specific feedback activation of the three AKT isoforms (AKT1, AKT2 and AKT3) was observed after mTOR inhibition. As activation of AKT might limit the RAD001-mediated anti-tumor effect, the efficacy of combined mTOR and AKT inhibition was investigated using the allosteric AKT inhibitor MK-2206. Our results show that inhibition of AKT potentiates the efficacy of mTOR inhibition both in vitro and in a xenograft mouse model in vivo. Mechanistically, the antiproliferative effect of the pan-AKT inhibitor MK2206 in the CCA cell line TFK-1 was due to inhibition of AKT1 and AKT2, because knockdown of either AKT1 or AKT2, but not AKT3, showed a synergistic reduction of cell proliferation in combination with mTOR treatment. Finally, using an AKT isoform specific in vitro kinase assay, enzymatic activity of each of the three AKT isoforms was detected in all tissue samples from CCA patients, analyzed. In summary, our preclinical data suggest that combined targeting of mTOR and AKT using RAD001 and MK-2206 might be a new, effective strategy for the treatment of CCA.

Topics: Animals; Apoptosis; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Blotting, Western; Cell Cycle; Cell Proliferation; Cholangiocarcinoma; Drug Synergism; Everolimus; Flow Cytometry; Heterocyclic Compounds, 3-Ring; Humans; Immunoprecipitation; Mice; Phosphatidylinositol 3-Kinase; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Tumor Cells, Cultured; Tumor Stem Cell Assay

Cholangiocarcinoma (CC) is a malignant epithelium neoplasm that originates from the bile epithelium and for which there are few therapeutic strategies. The mTOR pathway involved in many cellular processes was reported to be up-regulated in various cancers. We investigated the activation of the AKT/mTOR pathway in CC cell lines with different degrees of dedifferentiation and found that rapamycin could suppress the motility and the peritoneal dissemination of sarcomatoid SCK cells. Inhibition of the mTOR pathway with rapamycin decreased significantly the number of tumor nodules and prolonged the survival rates of nude mice inoculated with sarcomatoid CC cells. Prolonged treatments with rapamycin were found to disrupt the mTORC2 assembly and to reduce the phosphorylation of STAT3 at Ser 727. Rapamycin decreased both mRNA and protein levels of MMP2 and Twist1, which are regulated by STAT3 and associated with cancer metastasis. The overexpression of STAT3 S727A lacking the phosphorylation site resulted in significantly less sensitivity to rapamycin than the overexpression of STAT3 WT. Taken together, our results suggest that rapamycin could suppress the motility of sarcomatoid CC by down-regulating p-STAT3 (S727) through the impairment of mTORC2 assembly.

Topics: Animals; Apoptosis; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Blotting, Western; Cell Adhesion; Cell Movement; Cell Proliferation; Cholangiocarcinoma; Down-Regulation; Humans; Immunoenzyme Techniques; Immunoprecipitation; Male; Mechanistic Target of Rapamycin Complex 2; Mice; Mice, Nude; Multiprotein Complexes; Peritoneal Neoplasms; Phosphorylation; Proto-Oncogene Proteins c-akt; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Sirolimus; STAT3 Transcription Factor; TOR Serine-Threonine Kinases; Tumor Cells, Cultured