Targeted therapy for biliary tract cancers

Optimal tissue sampling during ERCP and emerging molecular techniques for the differentiation of benign and malignant biliary strictures

Patients with cholangiocarcinoma have poor survival since the majority of patients are diagnosed at a stage precluding surgical resection, due to locally irresectable tumors and/or metastases. Optimization of diagnostic strategies, with a principal role for tissue diagnosis, is essential to detect cancers at an earlier stage amenable to curative treatment. Current barriers for a tissue diagnosis include both insufficient tissue sampling and a difficult cyto- or histopathological assessment. During endoscopic retrograde cholangiopancreatography, optimal brush sampling includes obtaining more than one brush within an individual patient to increase its diagnostic value. Currently, no significant increase of the diagnostic accuracy for the new cytology brush devices aiming to enhance the cellularity of brushings versus standard biliary brush devices has been demonstrated. Peroral cholangioscopy with bile duct biopsies appears to be a valuable tool in the diagnostic work-up of indeterminate biliary strictures, and may overcome current technical difficulties of fluoroscopic-guided biopsies. Over the past years, molecular techniques to detect chromosomal instability, mutations and methylation profiling of tumors have revolutionized, and implementation of these techniques on biliary tissue during diagnostic work-up of biliary strictures may be awaited in the near future. Fluorescence in situ hybridization has already been implemented in routine diagnostic evaluation of biliary strictures in several centers. Next-generation sequencing is promising for standard diagnostic care in biliary strictures, and recent studies have shown adequate detection of prevalent genomic alterations in KRAS, TP53, CDKN2A, SMAD4, PIK3CA, and GNAS on biliary brush material. Detection of DNA methylation of tumor suppressor genes and microRNAs may evolve over the coming years to a valuable diagnostic tool for cholangiocarcinoma. This review summarizes optimal strategies for biliary tissue sampling during endoscopic retrograde cholangiopancreatography and focuses on the evolving molecular techniques on biliary tissue to improve the differentiation of benign and malignant biliary strictures.

Enhancer of zeste homolog 2 (EZH2) regulates tumor angiogenesis and predicts recurrence and prognosis of intrahepatic cholangiocarcinoma

BACKGROUND

Enhancer of zeste homolog 2 (EZH2) is the catalytic subunit of the polycomb repressive complex 2 (PRC2) and regulates tumor malignancy by gene silencing via histone methylation. In this study we investigate the role of EZH2 in angiogenesis of intrahepatic cholangiocarcinoma (ICC).

METHODS

The influence of EZH2 on tumor angiogenesis was examined by bioinformatics analysis of a public database. We also assessed the correlation between EZH2 and vasohibin 1 (VASH1) expression in 47 patients with ICC by immunohistochemical (IHC) staining and in vitro gene silencing assays. The prognostic significance of EZH2 and VASH1 expression by IHC was also examined in the ICC cohort.

RESULTS

Bioinformatics analysis showed that EZH2 was associated with several angiogenesis gene sets in the public database. EZH2 suppressed VASH1 expression in in vitro assays and IHC studies. EZH2-high/VASH1-low status was independently associated with poor disease-free survival (P = 0.019) and poor overall survival (P = 0.0055).

CONCLUSION

The current study demonstrated that high EZH2 expression was associated with activation of tumor angiogenesis, and activation of the EZH2-mediated angiogenesis pathway predicted the prognosis of patients with ICC.

Anti-tumor effects of NVP-BKM120 alone or in combination with MEK162 in biliary tract cancer

There are currently no clinically validated therapeutic targets for biliary tract cancer (BTC). Despite promising results in other cancers, compounds targeting the phosphatidylinositol 3-kinase (PI3K)/AKT pathway, alone or in combination with Ras/Raf/MEK pathway inhibitors, have not been evaluated in BTC. Here, we examined the effects of a pan-PI3K inhibitor (BKM120) with or without a MEK inhibitor (MEK162), on eight human BTC cell lines carrying mutations in K-Ras and/or the PI3K catalytic subunit, PI3KCA. BKM120 inhibited the colony-forming ability and migration of BTC cells carrying wild-type (WT) PI3KCA and either mutant (MT) or WT K-Ras, but not of cells carrying mutations in both genes. In K-Ras-WT cells, BKM120 decreased the phosphorylation of Akt, its downstream effector kinase p70S6K, and the translational repressor 4E-BP1. Interestingly, BKM120 did not induce cell cycle arrest or suppress PI3K signaling via restoration of p-4E-BP1 in cells with PIK3CA and K-Ras double mutations. Notably, the resistance of dual K-Ras/PI3KCA-mutant cells to BKM120 was overcome by treatment with a combination of BKM120 and MEK162. Our findings thus support the clinical development of BKM120 monotherapy or BKM120/MEK162 combination therapy for the treatment of BTC.

Biliary cancer: Utility of next-generation sequencing for clinical management

BACKGROUND

Biliary tract cancers (BTCs) typically present at an advanced stage, and systemic chemotherapy is often of limited benefit.

METHODS

Hybrid capture-based comprehensive genomic profiling (CGP) was performed for 412 intrahepatic cholangiocarcinomas (IHCCAs), 57 extrahepatic cholangiocarcinomas (EHCCAs), and 85 gallbladder carcinomas (GBCAs). The mutational profile was correlated with the clinical outcome of standard and experimental therapies for 321 patients. Clinical variables, detected mutations, and administered therapies were correlated with overall survival (OS) in a Cox regression model.

RESULTS

The most frequent genetic aberrations (GAs) observed were tumor protein 53 (TP53; 27%), cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B; 27%), KRAS (22%), AT-rich interactive domain-containing protein 1A (ARID1A; 18%), and isocitrate dehydrogenase 1 (IDH1; 16%) in IHCCA; KRAS (42%), TP53 (40%), CDKN2A/B (17%), and SMAD4 (21%) in EHCCA; and TP53 (59%), CDKN2A/B (19%), ARID1A (13%), and ERBB2 (16%) in GBCA. Fibroblast growth factor receptor (FGFR; 11%) and IDH mutations (20%) were mostly limited to IHCCA but appeared to be mutually exclusive. In the IHCCA group, TP53 and KRAS mutations were associated significantly with poor OS, whereas FGFR2 mutations were associated with improved OS (P = .001), a younger age at onset, and female sex. IDH1/2 mutations were not prognostic. In a multivariate model, the effects of TP53 and FGFR GAs remained significant (P < .05). Patients with FGFR GAs had superior OS with FGFR-targeted therapy versus standard regimens (P = .006). Targeted therapy in IHCCA was associated with a numerical OS improvement (P = .07).

CONCLUSIONS

This is the largest clinically annotated data set of BTC cases with CGP and indicates the potential of CGP for improving outcomes. CGP should be strongly considered in the management of BTC patients. Cancer 2016;122:3838-3847. © 2016 American Cancer Society.

A case of advanced intrahepatic cholangiocarcinoma accidentally, but successfully, treated with capecitabine plus oxaliplatin (CAPOX) therapy combined with bevacizumab: a case report

Although surgical resection is the only way to cure biliary tract cancer (BTC), most BTCs are unresectable by the time they are diagnosed. Chemotherapy is usually used to treat unresectable BTC, but its impact on survival is small. Here, we report the case of a 70-year-old woman with a locally advanced intrahepatic cholangiocarcinoma that was initially diagnosed as an unresectable liver metastasis from colon cancer that had invaded all of the major hepatic veins. However, the tumor was noticeably reduced after treatment with CAPOX plus bevacizumab, which is an uncommon therapy for BTC. The tumor was finally resected by inferior right hepatic vein-preserving left hepatic trisectionectomy combined with a resection of the right hepatic vein after a right hepatic vein embolization.

Clinical aspects and perspectives of erlotinib in the treatment of patients with biliary tract cancer

INTRODUCTION

Patients with non-resectable biliary tract cancer have a poor prognosis even if treated with systemic chemotherapy. One hope for improving treatment is through molecular biology and the characterization of specific cancer driving alterations followed by the design of targeted drugs. The epidermal growth factor receptor system is upregulated in many cancers and can be targeted by the protein kinase inhibitor erlotinib. Erlotinib has demonstrated a clinically applicable effect in pancreatic and lung cancer Areas covered: In this review, the author presents the published clinical data about erlotinib in biliary tract cancer. The data is interpreted with respect to its clinical value and in regards to its future development.

EXPERT OPINION

Erlotinib has low activity as a monotherapy, but has shown synergistic effects when combined with bevacizumab. The only phase III trial with erlotinib was negative, but suggested improved progression free survival in cholangiocarcinoma patients when added to gemcitabine and oxaliplatin. There is no clinical, radiological or molecular marker to guide therapy, but genomic profiling and basket or umbrella trials may be useful in identifying the subset of patients benefitting from erlotinib. Until this subgroup has been defined, erlotinib has no value to biliary tract cancer patients in the daily clinic.

Evaluation and management of intrahepatic and extrahepatic cholangiocarcinoma

Cholangiocarcinomas are rare biliary tract tumors that are often challenging to diagnose and treat. Cholangiocarcinomas are generally categorized as intrahepatic or extrahepatic depending on their anatomic location. The majority of patients with cholangiocarcinoma do not have any of the known or suspected risk factors and present with advanced disease. The optimal evaluation and management of patients with cholangiocarcinoma requires thoughtful integration of clinical information, imaging studies, cytology and/or histology, as well as prompt multidisciplinary evaluation. The current review focuses on recent advances in the diagnosis and treatment of patients with cholangiocarcinoma and, in particular, on the role of endoscopy, surgery, transplantation, radiotherapy, systemic therapy, and liver-directed therapies in the curative or palliative treatment of these individuals. Cancer 2016;122:1349-1369. © 2016 American Cancer Society.

Macrophage migration inhibitory factor - a therapeutic target in gallbladder cancer

Background

Poor prognosis in gallbladder cancer is due to late presentation of the disease, lack of reliable biomarkers for early diagnosis and limited targeted therapies. Early diagnostic markers and novel therapeutic targets can significantly improve clinical management of gallbladder cancer.

Methods

Proteomic analysis of four gallbladder cancer cell lines based on the invasive property (non-invasive to highly invasive) was carried out using the isobaric tags for relative and absolute quantitation labeling-based quantitative proteomic approach. The expression of macrophage migration inhibitory factor was analysed in gallbladder adenocarcinoma tissues using immunohistochemistry. In vitro cellular assays were carried out in a panel of gallbladder cancer cell lines using MIF inhibitors, ISO-1 and 4-IPP or its specific siRNA.

Results

The quantitative proteomic experiment led to the identification of 3,653 proteins, among which 654 were found to be overexpressed and 387 were downregulated in the invasive cell lines (OCUG-1, NOZ and GB-d1) compared to the non-invasive cell line, TGBC24TKB. Among these, macrophage migration inhibitory factor (MIF) was observed to be highly overexpressed in two of the invasive cell lines. MIF is a pleiotropic proinflammatory cytokine that plays a causative role in multiple diseases, including cancer. MIF has been reported to play a central role in tumor cell proliferation and invasion in several cancers. Immunohistochemical labeling of tumor tissue microarrays for MIF expression revealed that it was overexpressed in 21 of 29 gallbladder adenocarcinoma cases. Silencing/inhibition of MIF using siRNA and/or MIF antagonists resulted in a significant decrease in cell viability, colony forming ability and invasive property of the gallbladder cancer cells.

Conclusions

Our findings support the role of MIF in tumor aggressiveness and suggest its potential application as a therapeutic target for gallbladder cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1855-z) contains supplementary material, which is available to authorized users.

Gallbladder cancer in Chile: what have we learned?

PURPOSE OF REVIEW

Gallbladder cancer (GBC) should be considered an orphan disease in oncology and represent a unique carcinogenetic model. This review will analyse some of the current aspects of GBC.

RECENT FINDINGS

Chile has the highest incidence and mortality of GBC in the world. Most patients are diagnosed in advanced stages with few treatment options. During the last two decades, little progress has been made in early diagnosis and treatment. At the molecular level, recent access to next-generation sequencing and other techniques for detecting the mutations of multiple genes have made advances in this area.

SUMMARY

The use of therapies targeted according to the detection of specific molecular alterations is in the early stages of evaluation and could represent a significant advance in the treatment of a large number of patients from developing countries.

Prognostic value of neutrophil distribution in cholangiocarcinoma

AIM: To explore the relationship of clinicopathological features and the distribution of neutrophils in the tumor microenvironment with the prognosis of cholangiocarcinoma.

METHODS: Two hundred and fifty-four formalin-fixed and paraffin embedded tissue blocks were analyzed, including tissues from cholangiocarcinoma (n = 254), and tumor adjacent tissues (n = 238). Tissue sections were stained for CD15 using immunohistochemical staining. CD15 expression was detected to identify the distribution of neutrophils in the local tumor microenvironment. The neutrophil density of the tumor tissues and the adjacent tumor tissues was detected to reflect their inflammatory status. Clinical data and follow-up information of cholangiocarcinoma patients who underwent surgery from January 2004 to December 2010 were analyzed retrospectively. The relationship between clinicopathological features and the distribution of neutrophils with prognosis of the patients were analyzed.

RESULTS: The positive expression level of CD15 was only significantly related to the TNM stage. CD15 expression was higher in tumor tissues than in adjacent tissues (73.6% vs 54.6%), with significant differences. Patients with high expression of CD15 had significantly shorter overall survival (OS) than those with low expression of CD15 (median overall survival time 39.77 mo vs 16.87 mo, P = 0.008). Patients with high CD15 expression had significantly shorter disease free survival time (DFS) than those with low expression of CD15 (median DFS 38.27 mo vs 16.83 mo, P = 0.029). COX multivariate analysis indicated that high CD15 expression in tumor tissues was an independent risk factor for predicting OS for patients with cholangiocarcinoma [P = 0.012, relative risk (RR) = 1.601], but it was not an independent risk factor for predicting DFS (P = 0.073, RR = 1.462).

CONCLUSION: Patients with high CD15 expression in cancer tissues had shorter DFS and OS. High expression of CD15 is an independent risk factor for OS.

Anticancer activity of streptochlorin, a novel antineoplastic agent, in cholangiocarcinoma

BACKGROUND

The aim of this study is to investigate the anticancer activity of streptochlorin, a novel antineoplastic agent, in cholangiocarcinoma.

METHODS

The anticancer activity of streptochlorin was evaluated in vitro in various cholangiocarcinoma cell lines for apoptosis, proliferation, invasiveness, and expression of various protein levels. A liver metastasis model was prepared by splenic injection of HuCC-T1 cholangiocarcinoma cells using a BALB/c nude mouse model to study the systemic antimetastatic efficacy of streptochlorin 5 mg/kg at 8 weeks. The antitumor efficacy of subcutaneously injected streptochlorin was also assessed using a solid tumor xenograft model of SNU478 cells for 22 days in the BALB/c nude mouse.

RESULTS

Streptochlorin inhibited growth and secretion of vascular endothelial growth factor by cholangiocarcinoma cells in a dose-dependent manner and induced apoptosis in vitro. In addition, streptochlorin effectively inhibited invasion and migration of cholangiocarcinoma cells. Secretion of vascular endothelial growth factor and activity of matrix metalloproteinase-9 in cholangiocarcinoma cells were also suppressed by treatment with streptochlorin. Streptochlorin effectively regulated metastasis of HuCC-T1 cells in a mouse model of liver metastasis. In a tumor xenograft study using SNU478 cells, streptochlorin significantly inhibited tumor growth without changes in body weight when compared with the control.

CONCLUSION

These results reveal that streptochlorin is a promising chemotherapeutic agent to the treatment of cholangiocarcinoma.

Multigene mutational profiling of cholangiocarcinomas identifies actionable molecular subgroups

One-hundred-fifty-three biliary cancers, including 70 intrahepatic cholangiocarcinomas (ICC), 57 extrahepatic cholangiocarcinomas (ECC) and 26 gallbladder carcinomas (GBC) were assessed for mutations in 56 genes using multigene next-generation sequencing. Expression of EGFR and mTOR pathway genes was investigated by immunohistochemistry. At least one mutated gene was observed in 118/153 (77%) cancers. The genes most frequently involved were KRAS (28%), TP53 (18%), ARID1A (12%), IDH1/2 (9%), PBRM1 (9%), BAP1 (7%), and PIK3CA (7%). IDH1/2 (p=0.0005) and BAP1 (p=0.0097) mutations were characteristic of ICC, while KRAS (p=0.0019) and TP53 (p=0.0019) were more frequent in ECC and GBC. Multivariate analysis identified tumour stage and TP53 mutations as independent predictors of survival. Alterations in chromatin remodeling genes (ARID1A, BAP1, PBRM1, SMARCB1) were seen in 31% of cases. Potentially actionable mutations were seen in 104/153 (68%) cancers: i) KRAS/NRAS/BRAF mutations were found in 34% of cancers; ii) mTOR pathway activation was documented by immunohistochemistry in 51% of cases and by mutations in mTOR pathway genes in 19% of cancers; iii) TGF-ß/Smad signaling was altered in 10.5% cancers; iv) mutations in tyrosine kinase receptors were found in 9% cases. Our study identified molecular subgroups of cholangiocarcinomas that can be explored for specific drug targeting in clinical trials.

A patient with cholangiocarcinoma demonstrating pathologic complete response to chemotherapy: exploring the role of neoadjuvant therapy in biliary tract cancer

The role of neoadjuvant chemotherapy and/or radiation for localized or potentially resectable cholangiocarcinoma (CCA) has not been well established. We present here the case of a patient with an extrahepatic CCA who achieved a pathologic complete response after undergoing preoperative gemcitabine-based chemotherapy, without sequential or concurrent use of radiation. Further evaluation of neoadjuvant strategies in CCA, including not only combined-modality therapy but also the use of chemotherapy exclusively, is warranted in prospective study design.

Hilar cholangiocarcinoma: diagnosis, treatment options, and management

Hilar cholangiocarcinoma (HC) is a rare disease with a poor prognosis which typically presents in the 6(th) decade of life. Of the 3,000 cases seen annually in the United States, less than one half of these tumors are resectable. A variety of risk factors have been associated with HC, most notably primary sclerosing cholangitis (PSC), biliary stone disease and parasitic liver disease. Patients typically present with abdominal pain, pruritis, weight loss, and jaundice. Computed topography (CT), magnetic resonance imaging (MRI), and ultrasound (US) are used to characterize biliary lesions. Endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic cholangiography (PTC) assess local ductal extent of the tumor while allowing for therapeutic biliary drainage. MRCP has demonstrated similar efficacies to PTC and ERCP in identifying anatomic extension of tumors with less complications. Treatment consists of surgery, radiation, chemotherapy and photodynamic therapy. Biliary drainage of the future liver remnant should be performed to decrease bilirubin levels thereby facilitating future liver hypertrophy. Standard therapy consists of surgical margin-negative (R0) resection with extrahepatic bile duct resection, hepatectomy and en bloc lymphadenectomy. Local resection should not be undertaken. Lymph node invasion, tumor grade and negative margins are important prognostic indicators. In instances where curative resection is not possible, liver transplantation has demonstrated acceptable outcomes in highly selected patients. Despite the limited data, chemotherapy is indicated for patients with unresectable tumors and adequate functional status. Five-year survival after surgical resection of HC ranges from 10% to 40% however, recurrence can be as high as 50-70% even after R0 resection. Due to the complexity of this disease, a multi-disciplinary approach with multimodal treatment is recommended for this complex disease.

Cholangiocarcinoma cell line TK may be useful for the pharmacokinetic study of the chemotherapeutic agent gemcitabine

Cholangiocarcinoma is a disease with a poor prognosis. A human cholangiocarcinoma cell line, TK, was previously established to enable further understanding of the disease. We conducted this investigation to determine whether or not the TK line is useful for pharmacokinetic study of the chemotherapeutic agent gemcitabine (GEM). Along with the BXPC3 human pancreatic adenocarcinoma cell line, the sensitivity to and effects on the TK cell line of GEM were compared. The influence of deoxycytidine kinase (dCK) transduction was also comparatively investigated. The effects of GEM in terms of drug sensitivity of the TK cell line, cell cycle and levels of transcripts of key enzymes were comparable to the BXPC3 cell line. Responses to the drug were similar in both cell lines. In contrast to pancreatic carcinoma, cell lines for research on cholangiocarcinoma have been limited. This study suggests the application of the TK cell line to the pharmacokinetic study of the chemosensitization of therapeutic drugs, such as GEM.

Morphological study of the TK cholangiocarcinoma cell line with three-dimensional cell culture

Cholangiocarcinoma is an intractable carcinoma originating from the bile duct epithelium. To gain an understanding of the cell biology of cholangiocarcinoma, in vitro cell culture is valuable. However, well‑characterized cell lines are limited. In the present study, the morphology of the TK cholangiocarcinoma cell line was analyzed by three‑dimensional culture. Dispersed TK cells were injected into a gelatin mesh scaffold and cultivated for 3‑20 days. The morphology of the TK cells was investigated by phase‑contrast microscopy, optical microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). TK cells were observed to proliferate three-dimensionally in the scaffold. The cells exhibited a globoid structure and attached to the scaffold. The SEM observation demonstrated typical microvilli and plicae on the surface of the structure. Light microscopy and TEM confirmed intercellular and cell‑to‑scaffold attachment in the three‑dimensional mesh. The culture also exhibited the formation of a duct-like structure covered by structured microvilli. In conclusion, three‑dimensional culture of TK cells demonstrated the morphological characteristics of cholangiocarcinoma in vitro. Production of high levels of carbohydrate antigen (CA)19‑9, CA50 and carcinoembryonic antigen was previously confirmed in the TK cell line. As a characteristic morphology was demonstrated in the present study, the TK cholangiocarcinoma cell line may be useful as an experimental model for further study of cholangiocarcinoma.

Epigenetic therapy with the histone methyltransferase EZH2 inhibitor 3-deazaneplanocin A inhibits the growth of cholangiocarcinoma cells

Enhancer of zeste homolog 2 (EZH2) is involved in malignant transformation and the biological aggressiveness of several human malignancies. Growing evidence indicates that EZH2 may be an appropriate therapeutic target for malignancies, including cholangiocarcinoma. Recently, an S-adenosyl-L-homocysteine hydrolase inhibitor, 3-deazaneplanocin A (DZNep) was shown to deplete and inhibit EZH2. The aim of this study was to determine the effect of DZNep and the combination of gemcitabine and DZNep in cholangiocarcinoma cells. The effects of DZNep and its combination with gemcitabine were assessed in the cholangiocarcinoma cell lines RBE and TFK-1. DZNep depleted the cellular levels of EZH2 and inhibited the associated histone H3 lysine 27 trimethylation. DZNep treatment resulted in the inhibition of proliferation in the cholangiocarcinoma cell lines, and the combination of DZNep and gemcitabine showed synergistic inhibition of cell proliferation. DZNep induced apoptosis and G1 phase cell cycle arrest in cholangiocarcinoma cells, and the combination of DZNep and gemcitabine enhanced the induced apoptosis and G1 arrest when compared with gemcitabine alone. Inhibition of cell proliferation by DZNep was partially associated with upregulation of p16INK4a and p17KIP1. The present study shows that DZNep inhibits cell proliferation by inducing G1 arrest and apoptosis. These results indicate that an epigenetic therapy that pharmacologically targets EZH2 via DZNep may constitute a novel approach for the treatment of cholangiocarcinoma.

A perspective on molecular therapy in cholangiocarcinoma: present status and future directions

Cholangiocarcinoma (CCA) is an orphan cancer with limited understanding of its genetic and genomic pathogenesis. Typically, it is highly treatment-refractory and patient outcome is dismal. Currently, there are no approved therapeutics for CCA and surgical resection remains the only option with curative intent. Clinical trials are currently being performed in a mixed cohort of biliary tract cancers that includes intrahepatic CCA, extrahepatic/perihilar CCA, distal extrahepatic CCA, gallbladder carcinoma and, in rare cases, even pancreatic cancers. Today, clinical trials fail primarily because they are underpowered mixed cohorts and designed without intent to enrich for markers to optimize success for targeted therapy. This review aims to emphasize current clinical attempts for targeted therapy of CCA, as well as highlight promising new candidate pathways revealed by translational genomics.

A phase II trial of gemcitabine, irinotecan and panitumumab in advanced cholangiocarcinoma

BACKGROUND

Current data suggest that chemotherapy combinations may be superior to single agents in biliary tract cancer. The epidermal growth factor receptor (EGFR) pathway appears to be associated with tumor stage, prognosis and response to therapy. This trial was designed to evaluate the tolerability and efficacy of the combination of panitumumab, a monoclonal anti-EGFR antibody, with gemcitabine and irinotecan.

PATIENTS AND METHODS

Patients with advanced (unresectable or metastatic) cholangiocarcinoma, ECOG PS 0-2, and adequate organ function were treated with panitumumab (9 mg/kg) on day 1, and gemcitabine (1000 mg/m(2)) and irinotecan (100 mg/m(2)) on days 1 and 8 of a 21-day cycle. The primary objective was to evaluate the 5-month progression-free survival (PFS). Secondary objectives included overall response rate (ORR) and overall survival (OS). Mutational analyses of EGFR, KRAS and BRAF were carried out when feasible.

RESULTS

Thirty-five patients received a median of 7 (0-30) cycles. The most common grade 3/4 toxic effects were neutropenia (10 patients, 29%), thrombocytopenia (10 patients, 29%), skin rash (13 patients, 37%) and dehydration (9 patients, 26%). Two patients had CR, 9 had partial response (PR), and 15 had SD for a disease-control rate of 74% (by RECIST) in 28 assessable patients. Two patients went on to have surgical resection. The 5-month PFS was 69%. The median PFS was 9.7 months and the median OS was 12.9 months. In 17 testable samples, no EGFR or BRAF mutations were identified; there were 7 KRAS mutations, with no difference in OS by KRAS status.

CONCLUSIONS

This study showed encouraging efficacy of this regimen with good tolerability. Further study in this area is warranted. Clinical Trials Number: The trial was registered with the National Cancer Institute (www.clinicaltrials.gov identifier NCT00948935).

Clinical significance of L-type amino acid transporter 1 expression as a prognostic marker and potential of new targeting therapy in biliary tract cancer. BMC Cancer. 2013;13:482. [PMID: 24131658 PMCID: PMC4016614 DOI: 10.1186/1471-2407-13-482]

BACKGROUND

The expression of L-type amino acid transporter 1 (LAT1) has been described to play essential roles in tumor cell growth and survival. However, it remains unclear about the clinicopathological significance of LAT1 expression in biliary tract cancer. This study was conducted to determine biological significance of LAT1 expression and investigate whether LAT1 could be a prognostic biomarker for biliary tract cancer.

METHODS

A total of 139 consecutive patients with resected pathologic stage I-IV biliary tract adenocarcinoma were retrospectively reviewed. Tumor specimens were stained by immunohistochemistry for LAT1, Ki-67, microvessel density determined by CD34, and p53; and prognosis of patients was correlated. Biological significance of LAT1 expression was investigated by in vitro and in vivo experiments with LAT inhibitor, 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH) using cholangiocarcinoma cell line.

RESULTS

In total patients, high LAT1 expressions were recognized in 64.0%. The expression of LAT1 was closely correlated with lymphatic metastases, cell proliferation and angiogenesis, and was a significant indicator for predicting poor outcome after surgery. LAT1 expression was a significant independent predictor by multivariate analysis. Both in vitro and in vivo preliminary experiments indicated that BCH significantly suppressed growth of the tumor and yielded an additive therapeutic efficacy to gemcitabine and 5-FU.

CONCLUSIONS

High expression of LAT1 is a promising pathological marker to predict the outcome in patients with biliary tract adenocarcinoma. Inhibition of LAT1 may be an effective targeted therapy for this distressing disease.

AKT/mTOR substrate P70S6K is frequently phosphorylated in gallbladder cancer tissue and cell lines

Background

Gallbladder carcinoma is a highly malignant tumor and a public health problem in some parts of the world. It is characterized by a poor prognosis and its resistance to radio and chemotherapy. There is an urgent need to develop novel therapeutic alternatives for the treatment of gallbladder carcinoma. The mammalian target of the rapamycin (mTOR) signaling pathway is activated in about 50% of human malignancies, and its role in gallbladder carcinoma has previously been suggested. In the present study, we investigated the phosphorylation status of the mTOR substrate p70S6K in preneoplastic and neoplastic gallbladder tissues and evaluated the effect of three mTOR inhibitors on cell growth and migration in gallbladder carcinoma cell lines.

Methods

Immunohistochemical staining of phospho-p70S6K was analyzed in 181 gallbladder carcinoma cases, classified according to lesion type as dysplasia, early carcinoma, or advanced carcinoma. Protein expression of AKT/mTOR members was also evaluated in eight gallbladder carcinoma cell lines by Western blot analysis. We selected two gallbladder carcinoma cell lines (G415 and TGBC-2TKB) to evaluate the effect of rapamycin, RAD001, and AZD8055 on cell viability, cell migration, and protein expression.

Results

Our results showed that phospho-p70S6K is highly expressed in dysplasia (66.7%, 12/18), early cancer (84.6%, 22/26), and advanced cancer (88.3%, 121/137). No statistical correlation was observed between phospho-p70S6K status and any clinical or pathological features, including age, gender, ethnicity, wall infiltration level, or histological differentiation (P < 0.05). In vitro treatment with rapamycin, RAD001, and AZD8055 reduced cell growth, cell migration, and phospho-p70S6K expression significantly in G-415 and TGBC-2TKB cancer cells (P < 0.001).

Conclusion

Our findings confirm the upregulation of this signaling pathway in gallbladder carcinoma and provide a rationale for the potential use of mTOR inhibitors as a therapeutic strategy for human gallbladder carcinoma.