Cholangiocarcinoma--current classification and challenges towards personalised medicine

Mass spectrometry-based analysis of formalin-fixed, paraffin-embedded distal cholangiocarcinoma identifies stromal thrombospondin-2 as a potential prognostic marker

Background

Distal cholangiocarcinoma is an aggressive malignancy with a dismal prognosis. Diagnostic and prognostic biomarkers for distal cholangiocarcinoma are lacking. The aim of the present study was to identify differentially expressed proteins between distal cholangiocarcinoma and normal bile duct samples.

Methods

A workflow utilizing discovery mass spectrometry and verification by parallel reaction monitoring was used to analyze surgically resected formalin-fixed, paraffin-embedded samples from distal cholangiocarcinoma patients and normal bile duct samples. Bioinformatic analysis was used for functional annotation and pathway analysis. Immunohistochemistry was performed to validate the expression of thrombospondin-2 and investigate its association with survival.

Results

In the discovery study, a total of 3057 proteins were identified. Eighty-seven proteins were found to be differentially expressed (q < 0.05 and fold change ≥ 2 or ≤ 0.5); 31 proteins were upregulated and 56 were downregulated in the distal cholangiocarcinoma samples compared to controls. Bioinformatic analysis revealed an abundance of differentially expressed proteins associated with the tumor reactive stroma. Parallel reaction monitoring verified 28 proteins as upregulated and 18 as downregulated in distal cholangiocarcinoma samples compared to controls. Immunohistochemical validation revealed thrombospondin-2 to be upregulated in distal cholangiocarcinoma epithelial and stromal compartments. In paired lymph node metastases samples, thrombospondin-2 expression was significantly lower; however, stromal thrombospondin-2 expression was still frequent (72%). Stromal thrombospondin-2 was an independent predictor of poor disease-free survival (HR 3.95, 95% CI 1.09–14.3; P = 0.037).

Conclusion

Several proteins without prior association with distal cholangiocarcinoma biology were identified and verified as differentially expressed between distal cholangiocarcinoma and normal bile duct samples. These proteins can be further evaluated to elucidate their biomarker potential and role in distal cholangiocarcinoma carcinogenesis. Stromal thrombospondin-2 is a potential prognostic marker in distal cholangiocarcinoma.

Expression of peritumoral SPARC during distal cholangiocarcinoma progression and correlation with outcome

Objectives: Distal cholangiocarcinoma (dCCA) is a malignancy with a dismal prognosis. One of the hallmarks is the presence of a rich desmoplastic stroma believed to contribute to tumor progression and treatment resistance. Secreted protein acidic and rich in cysteine (SPARC) is a matricellular glycoprotein implicated in tumor-stroma interaction with prognostic correlation across several malignancies. The aim of the present study was to evaluate the expression pattern and prognostic significance of SPARC in resected dCCA and paired lymph node metastasis.Materials and methods: SPARC expression was evaluated in 59 resected dCCA samples and 25 paired lymph node metastases as well as 10 benign bile duct samples using immunohistochemistry. Stromal SPARC expression was scored semi quantitatively. Survival was estimated using the Kaplan-Meier method with associated log-rank test.Results: SPARC expression was absent in normal bile ducts. In dCCA, peritumoral stromal SPARC was detectable in 47/59 (80%) of samples with 40/59 (68%) classified as high stromal SPARC expression. There was a significantly lower proportion of SPARC positive stroma in paired lymph node metastasis 17/25 (68%) than the corresponding primary tumors 24/25 (96%) (p = .016). Stromal SPARC expression was associated with the presence of lymph node metastasis; high SPARC expression 31/40 (78%) versus low SPARC expression 9/19 (47%) (p = .013). In the present material there was no significant association between stromal SPARC expression and survival.Conclusions: Stromal SPARC expression occurs frequently in dCCA. Although significantly lower than in primary tumors stromal SPARC is frequently retained in paired lymph node metastasis suggesting a possible role in the metastatic process of dCCA.

Expression of fibroblast activation protein and the clinicopathological relevance in distal cholangiocarcinoma

Objectives: The current survival of patients with distal cholangiocarcinoma (dCCA) is poor. There is a need to develop new prognostic and predictive biomarkers to improve the survival of patients. Fibroblast activation protein (FAP) expression has been associated with survival in several solid malignancies. The goal of this study was to evaluate the expression pattern and prognostic significance of FAP in dCCA.Materials and methods: FAP expression was examined in 57 resected dCCA specimens and 28 paired lymph node metastasis specimens, as well as 10 benign bile ducts using immunohistochemistry. FAP expression was scored in the epithelial and stromal component of the dCCA specimens. The association between FAP expression and prognosis was evaluated using univariable and multivariable statistical modeling.Results: FAP expression was absent in the benign controls. FAP expression was evident in the epithelial 43 (75%) and stromal compartment 34 (60%) of dCCA. There was no association between epithelial or stromal FAP expression and clinicopathological factors. Epithelial FAP expression (HR 0.4 95% CI 0.20-0.78; p=.007) but not stromal FAP expression was significantly associated with better survival in univariable and multivariable analysis.Conclusions: FAP overexpression is evident in dCCA. There was a positive association between epithelial FAP expression and better survival which merits further evaluation.

Establishment of cholangiocarcinoma cell lines from patients in the endemic area of liver fluke infection in Thailand

Cholangiocarcinoma is a rare type of cancer which is an increasingly discernible health threat. The disease is usually very difficult in diagnosis and various treatment modalities are typically not effective. Cholangiocarcinoma is a complex and very heterogeneous malignancy characterized by tumor location, different risk factors, molecular profiling, and prognosis. Cancer cell lines represent an important tool for investigation in various aspects of tumor biology and molecular therapeutics. We established two cell lines, KKU-452 and KKU-023, which were derived from patients residing in the endemic area of liver fluke infection in Thailand. Both of tumor tissues have gross pathology of perihilar and intrahepatic mass-forming cholangiocarcinoma. Two cell lines were characterized for their biological, molecular and genetic properties. KKU-452 and KKU-023 cells are both adherent cells with epithelium morphology, but have some differences in their growth pattern (a doubling time of 17.9 vs 34.8 h, respectively) and the expression of epithelial bile duct markers, CK7 and CK19. Cytogenetic analysis of KKU-452 and KKU-023 cells revealed their highly complex karyotypes; hypertriploid and hypotetraploid, respectively, with multiple chromosomal aberrations. Both cell lines showed mutations in p53 but not in KRAS. KKU-452 showed a very rapid migration and invasion properties in concert with low expression of E-cadherin and high expression of N-cadherin, whereas KKU-023 showed opposite characters. KKU-023, but not KKU-452, showed in vivo tumorigenicity in xenografted nude mice. Those two established cholangiocarcinoma cell lines with unique characters may be valuable for better understanding the process of carcinogenesis and developing new therapeutics for the patients

Transforming big data into computational models for personalized medicine and health care

Health care systems generate a huge volume of different types of data. Due to the complexity and challenges inherent in studying medical information, it is not yet possible to create a comprehensive model capable of considering all the aspects of health care systems. There are different points of view regarding what the most efficient approaches toward utilization of this data would be. In this paper, we describe the potential role of big data approaches in improving health care systems and review the most common challenges facing the utilization of health care big data.