Clinicopathological significance of S100 protein expression in cholangiocarcinoma

Recent Advancement in Diagnosis of Biliary Tract Cancer through Pathological and Molecular Classifications

Biliary tract cancers (BTCs), including intrahepatic, perihilar, and distal cholangiocarcinomas, as well as gallbladder cancer, are a diverse group of cancers that exhibit unique molecular characteristics in each of their anatomic and pathological subtypes. The pathological classification of BTCs compromises distinct growth patterns, including mass forming, periductal infiltrating, and intraductal growing types, which can be identified through gross examination. The small-duct and large-duct types of intrahepatic cholangiocarcinoma have been recently introduced into the WHO classification. The presentation of typical clinical symptoms, as well as the extensive utilization of radiological, endoscopic, and molecular diagnostic methods, is thoroughly detailed in the description. To overcome the limitations of traditional tissue acquisition methods, new diagnostic modalities are being explored. The treatment landscape is also rapidly evolving owing to the emergence of distinct subgroups with unique molecular alterations and corresponding targeted therapies. Furthermore, we emphasize the crucial aspects of diagnosing BTC in practical clinical settings.

Diagnostic Challenges during Inflammation and Cancer: Current Biomarkers and Future Perspectives in Navigating through the Minefield of Reactive versus Dysplastic and Cancerous Lesions in the Digestive System

In the setting of pronounced inflammation, changes in the epithelium may overlap with neoplasia, often rendering it impossible to establish a diagnosis with certainty in daily clinical practice. Here, we discuss the underlying molecular mechanisms driving tissue response during persistent inflammatory signaling along with the potential association with cancer in the gastrointestinal tract, pancreas, extrahepatic bile ducts, and liver. We highlight the histopathological challenges encountered in the diagnosis of chronic inflammation in routine practice and pinpoint tissue-based biomarkers that could complement morphology to differentiate reactive from dysplastic or cancerous lesions. We refer to the advantages and limitations of existing biomarkers employing immunohistochemistry and point to promising new markers, including the generation of novel antibodies targeting mutant proteins, miRNAs, and array assays. Advancements in experimental models, including mouse and 3D models, have improved our understanding of tissue response. The integration of digital pathology along with artificial intelligence may also complement routine visual inspections. Navigating through tissue responses in various chronic inflammatory contexts will help us develop novel and reliable biomarkers that will improve diagnostic decisions and ultimately patient treatment.

Bile liquid biopsy in biliary tract cancer

Biliary tract cancers are heterogeneous in etiology, morphology and molecular characteristics thus impacting disease management. Diagnosis is complex and prognosis poor. The advent of liquid biopsy has provided a unique approach to more thoroughly understand tumor biology in general and biliary tract cancers specifically. Due to their minimally invasive nature, liquid biopsy can be used to serially monitor disease progression and allow real-time monitoring of tumor genetic profiles as well as therapeutic response. Due to the unique anatomic location of biliary tract cancer, bile provides a promising biologic fluid for this purpose. This review focuses on the composition of bile and the use of these various components, ie, cells, extracellular vesicles, nucleic acids, proteins and metabolites as potential biomarkers. Based on the disease characteristics and research status of biliary tract cancer, considerable effort should be made to increase understanding of this disease, promote research and development into early diagnosis, develop efficient diagnostic, therapeutic and prognostic markers.

Novel cell subtypes of SPP1 + S100P+, MS4A1-SPP1 + S100P+ were key subpopulations in intrahepatic cholangiocarcinoma

BACKGROUND

In this study, we integrated single-cell RNA sequencing (scRNA-seq) data to investigate cell heterogeneity and utilized MSigDB and CIBERSORTx to explore the pathways of major cell types and the relationships between different cell subtypes. Subsequently, we explored the correlation of cell subtypes with survival and used Gene Set Enrichment Analysis (GSEA) analyses to assess the pathways associated with the infiltration of specific cell subtypes. Finally, multiplex immunohistochemistry in tissue microarray cohort were performed to validate differences in protein level and their correlation with survival.

RESULTS

iCCA presented a unique immune ecosystem, with increased proportions of Epi (epithelial)-SPP1-2, Epi-S100P-1, Epi-DN (double negative for SPP1 and S100P expression)-1, Epi-DN-2, Epi-DP (double positive for SPP1 and S100P expression)-1, Plasma B-3, Plasma B-2, B-HSPA1A-1, B-HSPA1A-2 cells, and decreased proportions of B-MS4A1. High level of Epi-DN-2, Epi-SPP1-1, Epi-SPP1-2, B-MS4A1, and low level of Epi-DB-1, Epi-S100P-1, and Epi-S100P-2 was significantly associated with longer overall survival (OS), and high level of B-MS4A1_Low_Epi-DN-2_Low was associated with the shortest OS. Moreover, the results of MsigDB and GSEA suggest that bile acid metabolism is a crucial process in iCCA. Finally, we found that S100P+, SPP1+, SPP1 + S100P+, and MS4A1-SPP1 + S100P+ were highly expressed, whereas MS4A1 was lowly expressed in iCCA, and patients with high level of S100P+, SPP1 + S100P+, and MS4A1-SPP1 + S100P+ exhibited shorter survival.

CONCLUSIONS

We identified the cell heterogeneity of iCCA, found that iCCA is a unique immune ecosystem with many cell subtypes, and showed that the novel cell subtypes of SPP1 + S100P+ and MS4A1-SPP1 + S100P+ were key subpopulations in iCCA.

TMT-based quantitative proteomic analysis reveals the underlying mechanisms of glycidyl methacrylate-induced 16HBE cell malignant transformation

Glycidyl methacrylate (GMA) has been widely used as tackifying/crosslinking copolymer monomer in the industrial section. Occupational and environmental exposure to GMA is inevitable. GMA is classified as a Group 2 A carcinogen. However, it still lacks a sufficient understanding of its carcinogenicity at the protein level. The major pathways and players during the malignant transformation process remain unknown. In this study, we first established and characterized a malignant transformation model using human bronchial epithelial (16HBE) cells exposed to 8 μg/mL GMA. Then the proteomics approach, western-blot analysis as well as quantitative PCR (qPCR) analysis were employed to investigate its underlying mechanisms of carcinogenicity. Our results showed that the 16HBE cells exposed to GMA and passaged to the 40th generation had undergone a malignant transformation. Proteomic analysis revealed that 123 proteins were significantly up-regulated while 160 proteins were down-regulated during the process of malignant transformation. Importantly, further pathway analysis identified the extracellular matrix-receptor (ECM-receptor) interaction pathway to be one of the major players mediating the process and most of the differentially expressed proteins (DEPs) were up-regulated, including two vital proteins, CD44 and MMP14, as well as members from integrin family. These results provide direct proteomic evidence that DEPs related to the ECM-receptor interaction pathway play an active role in reinforcing the carcinogenicity of GMA. The findings of this study might deepen our understanding of the underlying mechanisms of GMA carcinogenicity and thus facilitate the risk assessment of GMA.

Bile duct dysplasia and associated invasive carcinoma: clinicopathological features, diagnosis, and practical challenges

Cholangiocarcinoma represents the second most frequent type of primary liver cancer that develops through a multistep histopathologic sequence. Dysplasia in the biliary tract epithelium is a precursor lesion of cholangiocarcinoma. This review provides a practical overview of bile duct dysplasia in relation to invasive carcinoma, covering clinicopathological features, diagnostic criteria, differential diagnosis, useful testing modalities, and challenges in daily practice. The key features of biliary intraepithelial neoplasia, intraductal papillary neoplasm, intraductal tubulopapillary neoplasm, and mucinous cystic neoplasm are described. Important differential diagnoses are included. Common pitfalls in histopathologic interpretation of bile duct biopsies and frozen sections are discussed.

Research progress of bile biomarkers and their immunoregulatory role in biliary tract cancers

Biliary tract cancers (BTCs), including cholangiocarcinoma and gallbladder carcinoma, originate from the biliary epithelium and have a poor prognosis. Surgery is the only choice for cure in the early stage of disease. However, most patients are diagnosed in the advanced stage and lose the chance for surgery. Early diagnosis could significantly improve the prognosis of patients. Bile has complex components and is in direct contact with biliary tract tumors. Bile components are closely related to the occurrence and development of biliary tract tumors and may be applied as biomarkers for BTCs. Meanwhile, arising evidence has confirmed the immunoregulatory role of bile components. In this review, we aim to summarize and discuss the relationship between bile components and biliary tract cancers and their ability as biomarkers for BTCs, highlighting the role of bile components in regulating immune response, and their promising application prospects.

Influence of S100A2 in Human Diseases

S100 proteins are a family of low-molecular-weight proteins characterized by two calcium-binding sites with a helix-loop-helix (“EF-hand-type”) domain. The S100 family of proteins is distributed across various organs and can interact with diverse molecules. Among the proteins of the S100 family, S100 calcium-binding protein A2 (S100A2) has been identified in mammary epithelial cells, glands, lungs, kidneys, and prostate gland, exhibiting various physiological and pathological actions in human disorders, such as inflammatory diseases and malignant tumors. In this review, we introduce basic knowledge regarding S100A2 regulatory mechanisms. Although S100A2 is a tumor suppressor, we describe the various influences of S100A2 on cancer and inflammatory diseases.

Bile cytology diagnosis in challenging cases: Validation of diagnostic bile cytology criteria and extensive study for immunocytochemical markers

BACKGROUND

Bile cytology is useful in diagnosing biliary tract lesions, albeit often challenging due to equivocal findings. To achieve better diagnoses for clinical decisions, we conducted cytomorphological and immunocytochemical studies of bile cytology cases.

MATERIALS AND METHODS

We re-evaluated 40 bile cytology cases with initial equivocal diagnoses, taken from the cytology records of Jichi Medical University Hospital, including 1778 bile cytology specimens. First, we assessed the cases by the diagnostic bile cytology criteria of the Japanese Society of Clinical Cytology. Second, we searched for useful immunocytochemical markers by extensive immunohistochemical analyses using tissue microarray for 10 antibodies: S100P, IMP3, GLUT1, p53, S100A4, Mapsin, MUC17, CD10, MDM2, and SMAD4. Microarrays were from 257 extrahepatic bile duct carcinoma cases. To elucidate the utility of immunocytochemistry, we applied selected markers to immunocytochemical evaluation of the equivocal cases after cell transfer.

RESULTS

The criteria indicated a sensitivity 60%, specificity 87%, and accuracy 70%. Irregularly overlapping (88%), arranged (96%), and shaped (76%) nuclei were more common in malignant cases, while enlarged nuclei were more frequent in benign cases (67% vs. 28%). We applied S100P and IMP3, which showed higher accuracy (88% and 77%) in tissue microarray, to immunocytochemistry. The sensitivity of S100P and IMP3 were 69% and 70%, respectively. The specificity of S100P and IMP3 were 50% and 100%, respectively.

CONCLUSION

The criteria showed a certain effectiveness even in challenging cases, and some pitfalls associated with reactive changes of benign cells. Although comprehensive diagnosis including cytomorphology seems preferable, S100P and IMP3 are promising immunocytochemical markers.

The interaction between S100A2 and KPNA2 mediates NFYA nuclear import and is a novel therapeutic target for colorectal cancer metastasis

Nucleocytoplasmic transport of proteins is disrupted and dysregulated in cancer cells. Nuclear pore complexes and cargo proteins are two main transportation regulators. However, the mechanism regulating nucleocytoplasmic transport in cancer remains elusive. Here, we identified a S100A2/KPNA2 cotransport complex that transports the tumor-associated transcription factor NFYA in colorectal cancer (CRC). Through the S100A2/KNPA2 complex, depending on its interaction with S100A2, NFYA is transported to the nucleus and inhibits the transcriptional activity of E-cadherin, which in turn promotes CRC metastasis. Targeting the S100A2/KPNA2 binding sites with the specific inhibitor delanzomib is a potential therapeutic approach for CRC.

The S100 protein family in lung cancer

The S100 protein family is involved in the pathogenesis of several malignancies including lung cancer. Recent studies have shown that one member, S100A2, was over-expressed in advanced stage non-small cell lung cancer (NSCLC). Another, S100A6, demonstrated variable expression in different lung cancer subtypes. Research using NSCLC cell lines reported that SIX3 inhibited cell metastasis and proliferation via S100P down-regulation. This review represents an update on S100 proteins in lung cancer from 2017 to 2021 and includes the aforementioned as well as S100A4, S100A7, and S100B. Inconsistencies in mechanisms of action for S100A8/S100A9 are highlighted and a comprehensive evaluation of the most recent evidence for the S100 proteins in lung cancer is presented.

Dysplasia and carcinoma of the gallbladder: pathological evaluation, sampling, differential diagnosis and clinical implications

Pathological evaluation of gallbladder neoplasia remains a challenge. A significant proportion of cases presents as clinically and grossly inapparent lesions, and grossing protocols are not well established. Among epithelial alterations, pseudo-pyloric gland metaplasia is ubiquitous and of no apparent consequence, whereas goblet cell metaplasia and a foveolar change in surface cells require closer attention. Low-grade dysplasia is difficult to objectively define and appears to be clinically inconsequential by itself; however, extra sampling is required to exclude the possibility of accompanying more significant lesions. For high-grade dysplasia ('high-grade BilIN', also known as 'carcinoma in situ'), a complete sampling is necessary to rule out invasion. Designating in-situ or minimally invasive carcinomas limited to muscularis or above as early gallbladder carcinoma (EGBC) helps to alleviate the major geographical differences (West/East) in the criteria for 'invasiveness' to assign a case to pTis or pT1. Total sampling is crucial in proper diagnosis of such cases. A subset of invasive GBCs (5-10%) arise from the intracholecystic neoplasm (ICN, 'adenoma-carcinoma sequence') category. Approximately two-thirds of ICNs have invasive carcinoma. However, this propensity differs by subtype. True 'pyloric gland adenomas' (> 1 cm) are uncommon and scarcely associated with invasive carcinoma. A distinct subtype of ICN composed of tubular, non-mucinous MUC6⁺ glands [intracholecystic tubular non-mucinous neoplasm (ICTN)] forms a localised pedunculated polyp. Although it is morphologically complex and high-grade, it appears to be invasion-resistant. Some of the invasive carcinoma types in the gallbladder have been better characterised recently with adenosquamous, neuroendocrine, poorly cohesive and mucinous carcinomas often being more advanced and aggressive.

Increased Expression of S100B and RAGE in a Mouse Model of Bile Duct Ligation-induced Liver Fibrosis

BACKGROUND

Liver fibrosis is defined as the accumulation of the extracellular matrix and scar formation. The receptor for advanced glycation end products (RAGE) has been demonstrated to participate in fibrogenesis. S100B is a ligand of RAGE and exerts extracellular functions by inducing a series of signal transduction cascades. However, the involvement of S100B and RAGE in cholestasis-induced liver fibrosis remains unclear. In this study, we investigated S100B and RAGE expression during liver fibrosis in mice that underwent common bile duct ligation (BDL).

METHODS

BDL was performed in 10-week-old male C57BL/6J mice with sham control (n = 26) and BDL (n = 26) groups. Expression levels of S100B, RAGE and fibrotic markers in the livers from both groups at week 1 and 3 after BDL were examined by western blot and quantitative real-time reverse transcription polymerase chain reaction analysis. Liver fibrotic changes were examined by histological and ultrastructural analysis.

RESULTS

Histological staining with Sirius Red and the evaluation of the messenger RNA expression of fibrotic markers showed noticeable periportal fibrosis and bile duct proliferation. S100B was mainly present in bile duct epithelial cells, and its expression was upregulated in proportion to the ductular reaction during fibrogenesis by BDL. RAGE expression was also increased, and interestingly, triple immunofluorescence staining and transmission electron microscopy showed that both S100B and RAGE were expressed in proliferating bile duct epithelial cells and activated hepatic stellate cells (HSCs) of the BDL livers. In addition, in rat HSCs (HSC-T6), treatment with recombinant S100B protein significantly increased fibrotic markers in a dose-dependent manner, and RAGE small interfering RNA (siRNA) suppressed S100B-stimulated upregulation of fibrotic markers compared with cells treated with scramble siRNA and S100B.

CONCLUSION

These findings suggest that the increased expression of S100B and RAGE and the interaction between S100B and RAGE may play an important role in ductular reaction and liver fibrosis induced by BDL.

Prognostic Value of S100P Expression in Patients With Digestive System Cancers: A Meta-Analysis

Background

Digestive system cancers (DSCs) are associated with high morbidity and mortality. S100P has been reported as a prognostic biomarker in DSCs, but its prognostic value remains controversial. Accordingly, we conducted a meta-analysis to investigate whether S100P is correlated with overall survival (OS) of patients with DSCs. The relationship between S100P and clinicopathological features was also evaluated.

Methods

We systematically searched PubMed, Embase, Web of Science and Cochrane Library for eligible studies up to January 2020. In total, 16 publications with 1,925 patients were included.

Results

S100P overexpression was associated with poor OS of patient with DSCs (HR=1.54, 95% CI: 1.14–2.08, P=0.005). When stratified by anatomic structure, S100P overexpression was associated with poor prognosis in non-gastrointestinal tract cancers (HR=1.98, 95% CI: 1.44–2.72, P<0.001) but not in gastrointestinal tract cancers (HR=1.09, 95% CI: 0.66–1.81, P=0.727). When stratified by tumor type, S100P overexpression predicted poor OS in cholangiocarcinoma (HR=2.14, 95% CI: 1.30–3.50, P=0.003) and hepatocellular carcinoma (HR=1.91, 95% CI: 1.22–2.99, P =0.005) but not in gastric cancer (HR=0.97, 95% CI: 0.65–1.45, P=0.872), colorectal cancer (HR=1.18, 95% CI: 0.32–4.41, P=0.807), gallbladder cancer (HR=1.40, 95% CI: 0.84-2.34, P=0.198), and pancreatic cancer (HR=1.92, 95% CI: 0.99–3.72, P=0.053). Furthermore, high S100P expression was significantly associated with distant metastasis (OR=3.58, P=0.044), advanced clinical stage (OR=2.03, P=0.041) and recurrence (OR=1.66, P=0.007).

Conclusion

S100P might act as a prognostic indicator of non-gastrointestinal tract cancers.

Precancerous Lesions and Liver Atrophy as Risk Factors for Hepatolithiasis-Related Death after Liver Resection for Hepatolithiasis

BACKGROUND

Cholangiocarcinoma and secondary biliary cirrhosis can develop after liver resection for hepatolithiasis and are causes of hepatolithiasis-related death. We determined potential risk factors for hepatolithiasis-related death and subsequent cholangiocarcinoma, including precancerous lesions such as biliary intraepithelial neoplasia (BilIN) and intraductal papillary neoplasm of the bile duct, in patients undergoing liver resection for hepatolithiasis.

METHODS

The study cohort included 62 patients who underwent liver resection for hepatolithiasis without concomitant cholangiocarcinoma and had surgical specimens available for pathological examination. Univariate and multivariate analyses were conducted to examine risk factors associated with subsequent cholangiocarcinoma after hepatolithiasis and hepatolithiasis-related death. In 28 patients with BilIN lesions, the specimens were immunohistochemically stained for γ-H2AX and S100P.

RESULTS

In the study cohort, the causes of death were subsequent cholangiocarcinoma, biliary cirrhosis, and other diseases in 5, 3, and 7 patients, respectively. Liver atrophy, precancerous lesions, postoperative repeated cholangitis, and jaundice for ≥1 week during the follow-up period were risk factors for hepatolithiasis-related death. Multivariate analysis showed that liver atrophy and precancerous lesions were independent risk factors for hepatolithiasis-related death. Liver atrophy or precancerous lesions were also risk factors for subsequent cholangiocarcinoma by univariate analysis. The positive expression of γ-H2AX and S100P was observed in 18 and 14 of the 28 BilIN lesions, respectively.

CONCLUSIONS

Liver atrophy and precancerous lesions with malignant transformation were risk factors not only for subsequent cholangiocarcinoma but also hepatolithiasis-related death after liver resection for hepatolithiasis, indicating that long-term follow-up is necessary even after liver resection in patients harboring these risk factors.<br />.

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.

Common features between neoplastic and preneoplastic lesions of the biliary tract and the pancreas

the bile duct system and pancreas show many similarities due to their anatomical proximity and common embryological origin. Consequently, preneoplastic and neoplastic lesions of the bile duct and pancreas share analogies in terms of molecular, histological and pathophysiological features. Intraepithelial neoplasms are reported in biliary tract, as biliary intraepithelial neoplasm (BilIN), and in pancreas, as pancreatic intraepithelial neoplasm (PanIN). Both can evolve to invasive carcinomas, respectively cholangiocarcinoma (CCA) and pancreatic ductal adenocarcinoma (PDAC). Intraductal papillary neoplasms arise in biliary tract and pancreas. Intraductal papillary neoplasm of the biliary tract (IPNB) share common histologic and phenotypic features such as pancreatobiliary, gastric, intestinal and oncocytic types, and biological behavior with the pancreatic counterpart, the intraductal papillary mucinous neoplasm of the pancreas (IPMN). All these neoplastic lesions exhibit similar immunohistochemical phenotypes, suggesting a common carcinogenic process. Indeed, CCA and PDAC display similar clinic-pathological features as growth pattern, poor response to conventional chemotherapy and radiotherapy and, as a consequence, an unfavorable prognosis. The objective of this review is to discuss similarities and differences between the neoplastic lesions of the pancreas and biliary tract with potential implications on a common origin from similar stem/progenitor cells.

Prognostic role of BAP-1 and PBRM-1 expression in intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) has universally poor outcome, mainly due to its late clinical presentation. Identification of specific biomarkers and development of effective treatment are still urgently required. Mutations in PBRM-1 and BAP-1 genes, and the expression of S100P have been related to survival in ICC. miR-31 seems also to play important regulatory functions in ICC and it directly regulates BAP-1 expression in lung cancer. In this study, tissue expression of BAP-1, PBRM-1, S100P, and miR-31 was investigated in ICC and correlated with clinical-pathological features. Sixty-one consecutive patients who underwent curative hepatic resection for ICC were enrolled. None received any therapy prior to surgery. Immunostaining for BAP-1, PBRM-1, and S100P, and in situ hybridization for miR-31 were performed, using tissue microarray slides. A strong retained expression of BAP-1 and PBRM-1 was associated with a reduced overall (p = 0.04 and p = 0.002, respectively) and disease-free survival (p = 0.05 and p = 0.02, respectively). An overexpression of S100P was related to a reduced overall survival (p = 0.005). The multivariate analyses identified the presence of perineural invasion and the retained PBRM-1 expression as independent predictors of worse overall [p = 0.02, hazard ratio (HR) = 2.25 (1.16-4.39) and p = 0.001, HR = 3.13 (1.56-6.28), respectively] and disease-free survivals [p = 0.03, HR = 2.43 (1.09-5.4) and p = 0.03, HR = 2.51 (1.11-5.67), respectively]. An overexpression of S100P was predictive of a worse overall survival [p = 0.02, HR = 1.66 (1.08-2.55)]. High levels of miR-31 were significantly associated to a low expression of BAP-1 protein (p = 0.03). In ICC, a retained expression of BAP-1 and PBRM-1, and an overexpression of S100P are related to a poor prognosis.

Thyroid-Like Intrahepatic Cholangiocarcinoma: Report of a Case and Review of the Literature

Intrahepatic cholangiocarcinoma is a relatively uncommon malignant neoplasm. We recently encountered an unusual case of intrahepatic cholangiocarcinoma that histologically resembled a thyroid carcinoma. A thorough review of the English literature revealed only 2 similar cases that have been previously reported. Immunohistochemical studies are imperative to confirm the diagnosis of cholangiocarcinoma and to exclude the possibility of metastatic thyroid carcinoma and other malignancies with thyroid-like features.

Depletion of S100A4+ stromal cells does not prevent HCC development but reduces the stem cell-like phenotype of the tumors

There is a pressing need for the development of novel approaches to treat and prevent hepatocellular carcinoma (HCC). The S100 calcium-binding protein S100A4 is associated with poor prognosis and metastasis in several human cancers. In addition, a role for S100A4 in modulating cancer-initiating cells stemness properties was recently proposed in head and neck and gastric cancers. Whether S100A4⁺ stromal cells contribute to tumor onset remains, however, an unanswered question. To address that question, we generated a new mouse model allowing for the depletion of S100A4⁺ cells in a mouse model of HCC with stemness properties, by crossing mice with hepatic deletion of phosphatase and tensin homolog (PTEN) with mice expressing viral thymidine kinase under the control of S100A4 promoter. Depletion of S100A4⁺ cells by ganciclovir injection did not prevent the development of HCC but reduced the stemness phenotype of the tumor as measured by the expression of progenitor cell, biliary cell and hepatocyte markers. The results were further confirmed by histology analysis showing reduction of cholangiolar tumor components and degree of oval cell hyperplasia in the adjacent liver. Depletion of S100A4⁺ cells had also some beneficial effect on the underlying liver disease with a reduction of NAS score, largely due to the reduction of inflammation. In conclusion, this study demonstrated that S100A4⁺ cells do not contribute to HCC onset but maintain the stemness phenotype of the tumor. This study also suggests for the first time a crosstalk between inflammation and stemness.

A review of S100 protein family in lung cancer

S100 protein family, representing 25 relatively small calcium binding proteins, has been reported to be involved in multiple stages of tumorigenesis and progression. These proteins are considered having potential value to be adopted as novel biomarkers in the detection and accurate prediction of many kinds of tumors, including lung cancer. As the one having the highest morbidity and mortality among all cancers, lung carcinoma is still occult for detection, especially at early stage. S100 proteins take participation in the lung neoplasia through playing intracellular and/or extracellular functions, therefore getting involved in a variety of biological processes such as differentiation, proliferation, and migration. A few members have also been testified to modulate TGF-β/Smad-3 mediated transcriptional activity of target genes involved in tumor promotion. In addition to that, a number of proteins in this family have already been reported to experience an abnormal trend in lung cancer at cell, serum and tissue levels. Thus, S100 proteins may serve as effective biomarkers for suspected or already diagnosed lung cancer patients. In future, S100 protein family might be applied as therapeutic targets in clinical treatment of lung cancer. In this review, we firstly summed up the biological and clinical evidence connecting S100 proteins and lung cancer, which has not been summarized before.

High Expression of S100A6 Predicts Unfavorable Prognosis of Lung Squamous Cell Cancer

Background

S100 family of proteins is mainly involved in regulation of intracellular calcium homeostasis. Aberrant expression of S100 family members has been reported in many types of cancers. However, as a member of S100 family, the prognostic value of S100A6 for lung squamous cell carcinoma (SCC) has not been well-studied.

Material/Methods

Using immunohistochemistry, we investigated the expression of S100A6 in 177 patients with SCC and further divided the cohort into a high S100A6 expression group and a low S100A6 expression group. The chi-square test was applied to analyze the correlation between S100A6 expression and clinicopathological factors. Univariate analysis using the Kaplan-Meier method was performed to compare the difference in survival rates between the high S100A6 expression group and the low S100A6 expression group; multivariate analysis with Cox regression model was used to identify independent prognostic risk factors.

Results

In our experiment, we demonstrated that the expression of S100A6 was significantly associated with patient age and tumor differentiation. High-expression of S100A6 was shown to be substantially related to the unfavorable prognosis of SCC. Moreover, our results confirmed that S100A6 was an independent risk factor for SCC prognosis, and could predict unfavorable prognosis.

Conclusions

High-expression of S100A6 was identified as an independent unfavorable prognostic factor for SCC, suggesting that targeting S100A6 may result in the development of potential targeted drug for SCC.

Intrahepatic cholangiocarcinoma: Molecular markers for diagnosis and prognosis

Intrahepatic cholangiocarcinoma (iCCA) is the second most common primary liver tumor with increasing incidence worldwide. The outcome of patients with iCCA is dismal owing to tumor's aggressiveness, late diagnosis and lack of effective treatment options. Detection of the tumor at early stages may make surgical resection, as only potential curative treatment, more feasible. Unfortunately, despite recent developments in imaging modalities and laboratory tests, the diagnosis of iCCA remains challenging and patients often present in advanced stages when surgery cannot be offered. Moreover, accurate assessment of disease burden is critical to optimize management strategy, including the use of adjuvant therapies and clinical trials. Identifying iCCA specific diagnostic and prognostic biomarkers has been a focus of interest among many investigators with a progressive increase in data on iCCA related to advances in "omics" technologies. We herein summarize iCCA biomarkers and define the molecular mechanisms underlying iCCA carcinogenesis, as well as highlight potential diagnostic and prognostic application of molecular biomarkers.

Pathology of intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCC) is a primary carcinoma of the liver with increasing significance and major pathogenic, clinical and therapeutic challenges. Classically, it arises from malignant transformation of cholangiocytes bordering small portal bile duct (BD) to second-order segmental large BDs. It has three major macroscopic growth pattern [mass-forming (MF), periductal infiltrative (PI), and intraductal growth (IG)] and histologically is a desmoplastic stroma-rich adenocarcinoma with cholangiocyte differentiation. Recent data pointed out noteworthy degree of heterogeneity in regards of their epidemiology and risk factors, pathological and molecular features, pathogenesis, clinical behaviors and treatment. Notably, several histological variants are described and can coexist within the same tumor. Several different cells of origin have also been depicted in a fraction of iCCs, amongst which malignant transformation of ductules, of hepatic stem/progenitor cells, of periductal glands or through oncogenic reprogramming of adult hepatocytes. A degree of pathological overlap with hepatocellular carcinoma (HCC) may be observed in a portion of iCC. A series of precursor lesions are today characterized and emphasize the existence of a multistep carcinogenesis process. Overall, these new data have brought up in proposal of new histological or molecular classifications, which could soon replace current anatomic-based classification and could have major impact on establishment of prognosis and on development of novel target treatment approaches.

Expression and clinicopathological significance of S100 calcium binding protein A2 in lung cancer patients of Chinese Han ethnicity

BACKGROUND

S100 family of calcium-binding proteins plays a significant role in the process of many kinds of tumors, including lung cancer. As an important member of this family, S100 calcium binding protein A2 (S100A2) has been confirmed to be associated with many biological processes, and has an abnormal expression in non-small cell lung cancer (NSCLC). However, the S100A2 status in lung cancer is still controversial and undefined.

METHODS

We evaluated the pattern and distribution of S100A2 in 109 cases of lung cancer, including five histological types (47 adenocarcinoma, 46 squamous cell carcinoma, 7 small cell carcinoma, 3 large cell carcinoma, and 6 atypical carcinoid), and 30 cases of paired adjacent normal lung tissues by means of immunohistochemistry.

RESULTS

Compared with the normal tissues (0/30), S100A2 experienced a dramatically upward trend of positive expression in lung cancer, with a positive rate of 68/109 (P<0.001). Specifically, squamous cell carcinoma, with 34/12, had the highest expression ratio, followed by large cell carcinoma (2/1), adenocarcinoma (31/16), and atypical carcinoid (1/5) respectively, while no S100A2 protein was detected in small cell carcinoma. Meanwhile, we firstly demonstrated that the high expression of S100A2 was significantly associated with the incidence of lymph node metastasis in adenocarcinoma (P=0.013).

CONCLUSIONS

The association between high S100A2 expression and NSCLC at the level of tissue, and S100A2 may serve as an effective biomarker for the diagnosis and prognosis of NSCLC in future.

An S100P-positive biliary epithelial field is a preinvasive intraepithelial neoplasm in nodular-sclerosing cholangiocarcinoma

Nodular-sclerosing cholangiocarcinoma (NS-CCA) is a common CCA of the intrahepatic large, perihilar, and distal bile ducts. Intraepithelial biliary neoplasms, such as the mucosal extension of carcinoma and preinvasive neoplastic lesions (ie, biliary intraepithelial neoplasia) reportedly occur in the bile ducts around CCA. In the present study, we collectively refer to these intraepithelial lesions as "intraepithelial neoplasms of the bile duct (IENBs)". We examined the IENBs in 57 surgically resected cases of NS-CCA. S100P immunostaining was used to help detect IENBs. The IENBs formed field(s) of continuous neoplastic biliary epithelial cells and showed a flat, micropapillary, or papillotubular configuration. IENBs could be classified into 3 categories based on their atypia: group A (neoplastic but not enough for malignancy), B (neoplastic and sufficiently well differentiated for high-grade dysplasia), and C (overtly malignant and variably differentiated). IENB was found in 31 of 57 cases, with group C the most common (26 cases) followed by group B (22 cases) and group A (16 cases). The expression of cancer-related molecules and MIB-1 index of groups A and B differed from those of invasive CCA, whereas these features of group C were relatively similar to those of invasive CCA. In conclusion, IENB was not infrequently found in NS-CCA and could be classified into 3 grades. Preinvasive lesions (biliary intraepithelial neoplasias) are likely to be found in groups A and B, whereas cancerization would be included in group C. The classification of IENB may be useful for future studies of the preinvasive intraepithelial neoplastic lesions of NS-CCAs.

Pathological spectrum of bile duct lesions from chronic bile duct injury to invasive cholangiocarcinoma corresponding to bile duct imaging findings of occupational cholangiocarcinoma

BACKGROUND

We aimed to identify the pathological characteristics of occupational cholangiocarcinoma.

METHODS

We examined the location and distribution of the carcinomas: atypical epithelium including biliary intraepithelial neoplasia (BilIN) and intraductal papillary neoplasm of the bile duct (IPNB); and chronic bile duct injuries in operative or autopsy liver specimens from 16 patients. We examined the detailed pathological findings and diagnostic imaging of three patients. Immunohistochemical analysis using primary antibodies against γH2AX and S100P was performed.

RESULTS

BilIN and chronic bile duct injury were observed in 16 patients, and IPNB or invasive IPNB was observed in 11 patients. BilIN, IPNB, and/or chronic bile duct injury were observed in almost all the large bile ducts. Regional dilatation of the bile ducts without tumor-induced obstruction revealed such pathological changes. Highly positive results for the γH2AX and S100P markers were noted in invasive carcinoma, BilIN, and IPNB, whereas positive results for γH2AX and negative results for S100P were noted in non-neoplastic biliary epithelium.

CONCLUSIONS

The carcinogenic process of occupational cholangiocarcinoma comprised chronic bile duct injury and DNA damage in almost all the large bile ducts, along with induction of precancerous lesions and development of invasive carcinoma. Such pathological findings reflected radiological changes on diagnostic imaging.

Comparative Proteomic Analysis of Human Cholangiocarcinoma Cell Lines: S100A2 as a Potential Candidate Protein Inducer of Invasion

Cholangiocarcinoma (CCA) is a bile duct cancer, commonly found in Asia including Thailand and especially in the northeastern region of Thailand. To identify the proteins involved in carcinogenesis and metastasis of CCA, protein expression profiles of high-invasive KKU-M213 and low-invasive KKU-100 cell lines were compared using a comparative GeLC-MS/MS proteomics analysis. A total of 651 differentially expressed proteins were detected of which 27 protein candidates were identified as having functions involved in cell motility. A total of 22 proteins were significantly upregulated in KKU-M213, whereas 5 proteins were downregulated in KKU-M213. S100A2, a calcium-binding protein in S100 protein family, is upregulated in KKU-M213. S100A2 is implicated in metastasis development in several cancers. The protein expression level of S100A2 was verified by Western blot analysis. Intriguingly, high-invasive KKU-M213 cells showed higher expression of S100A2 than KKU-100 cells, consistent with proteomic data, suggesting that S100A2 may be a key protein involved in the progression of CCA. However, the biological function of S100A2 in cholangiocarcinoma remains to be elucidated. S100A2 might be a potential biomarker as well as a novel therapeutic target in CCA metastasis.

Molecular diagnosis of intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinomas (iCCA) are primary intrahepatic malignancies originating from biliary epithelia. While both hepatocellular cancer and iCCA can present as mass lesions within the liver, these cancers are distinct in their morphology, etiology, pathology, natural history and response to therapy. There is a need for accurate and sensitive molecular markers for the diagnosis of iCCA. Recent advances in elucidating molecular and genetic characteristics of iCCA offer the potential of molecular-based diagnosis of iCCA. Specific genetic mutations of IDH1/2, BAP1, p53, and KRAS, FGFR gene fusions and alterations in microRNA have all been described in iCCA. Although there are no accurate serum or biliary biomarkers currently available for diagnosis of iCCA, several potential candidates have been identified. Knowledge of specific genetic or molecular abnormalities offers potential for individualized approaches for the treatment of patients with iCCA in the future.

The expression of S100A4 protein in human intrahepatic cholangiocarcinoma: clinicopathologic significance and prognostic value

Intrahepatic cholangiocarcinoma(ICC) is a highly malignant adenocarcinoma arising from bile duct epithelial cells of the intrahepatic biliary system with early hematogenous and lymphatic extrahepatic spread. The current treatment methods for ICC are far from ideal. Identifying novel effective prognostic biomarkers which might be related to the development and progression of ICC may help provide new therapeutic strategies. Both calcium-binding protein S100A4 and Matrix metalloproteinase-9(MMP-9) are correlated with development and progression of many carcinomas. In the present study, we investigated expression of S100A4 as well as MMP-9 in ICC tissues from 65 patients using immunohistochemistry. The correlation of S100A4 and MMP-9 expression with clinicopathological features and prognosis of patients were analyzed. S100A4 and MMP-9 were positively expressed in 32(49.2 %) and 35(53.8%) patients, respectively. The positive correlation between S100A4 and MMP-9 expression was statistically significant (P = 0.018). S100A4 positive expression was significantly correlated with vascular invasion (P = 0.008), lymph node metastasis (P = 0.029) and the TNM stage (P = 0.008). MMP-9 expression was not found to be correlated with any clinicopathological parameter. Patients with S100A4 positive expression had a significantly poorer overall survival rate than those with S100A4 negative expression (P = 0.000). MMP-9 positive expression was also correlated with poor survival (P = 0.044). However, only S100A4 expression (P = 0.004) and the surgical margin (P = 0.024) were significantly independent prognostic predictors by multivariate analysis. In conclusion, expression of S100A4 is correlated with MMP-9 expression and it could be a useful marker for predicting the progression, metastasis and prognosis of ICC.

Expression and diagnostic values of calretinin and CK5/6 in cholangiocarcinoma

BACKGROUND

Mesothelin, a mesothelial marker, has been found expressed in and as a potential treatment target of cholangioacarcinoma (CC). It is possible that CC may be derived from the cells sharing mesothelial markers. However, the expression of other mesothelial markers in CC is largely unknown.

METHODS

Thirty CC cases (10 extrahepatic and 20 intrahepatic) were retrieved from our institutional archive. The immunohistochemical study of Calretinin (DC8), WT1 (6F-H2), Lymphatic Endothelial Marker (D2-40), CK5/6 (D5/16 B4) and CK19 (b170) was done on formalin fixed paraffin embedded sections for 2-3 blocks of each case. We compared the expression levels between CC and normal bile duct (NBD) on the same block.

RESULTS

All of the CC and NBD are positive for CK19 (23/23) and negative for WT1 (0/23) and D2-40 (0/23), except one CC positive for D2-40(1/30, 3.3%) and one NBD positive for WT1 (1/23, 4.3%). Calretinin immunoreactivity was detected in 52.2% (12/23) of CC, but none in NBD (0/23). CK5/6 was also detectable in 73.3% (22/30) of CC and all NBD (30/30). Increased expression of calretinin and reduced expression of CK5/6 were more likely associated with CC than NBD (P < 0.001 and P = 0.002, respectively). The sequential staining pattern of positive calretinin and negative CK5/6 in calretinin negative cases has a sensitivity of 69.57% and a specificity of 100% for differentiating CC from NBD. CK5/6 expression was also more likely associated with well-differentiated CC (7/7 versus 12/20 in moderately differentiated, and 9/10 in poorly differentiated, P = 0.019) and extrahepatic CC (10/10 versus 12/20 in intrahepatic, P = 0.029), but there was no association between the calretinin expression and the CC grade or location.

CONCLUSION

Calretinin and CK5/6 immunohistochemical stains may be useful for diagnosing a CC. Their immunohistochemical results should be interpreted with caution in the cases with differential diagnoses of mesothelioma and CC. A full mesothelioma panel, including WT1 and/or D2-40, is recommended to better define a mesothelial lineage. The biology of calretinin and CK5/6 expression in CC is unclear, but might shed light on identifying therapeutic targets for CC.

Tumor necrosis factor-α modulates epithelial mesenchymal transition mediators ZEB2 and S100A4 to promote cholangiocarcinoma progression

BACKGROUND

The epithelial-mesenchymal transition (EMT) process strongly contributes to cancer metastasis. This study was to investigate the alteration of EMT-related proteins (ZEB1, ZEB2 and S100A4) in cholangiocarcinoma (CCA) tissues. The effect of tumor necrosis factor-α (TNF-α) on the expression of those molecules in CCA cells was investigated.

METHODS

The quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay was used to quantify ZEB1, ZEB2 and S100A4 mRNA levels in 50 CCA tissues and related its expression to clinicopathological data. ZEB2 protein immunostaining was investigated in 165 CCA tissues. The effect of TNF-α on EMT-related CCA cell migration was evaluated using qRT-PCR, immunofluorescence and transwell migration assays.

RESULTS

ZEB2 and S100A4 mRNA levels were found to be higher in CCA tissues. High levels of S100A4 mRNA and ZEB2 protein were significantly associated with CCA metastasis (P = 0.04 and P = 0.03). Moreover, a trend toward statistical association was found with high levels of both ZEB2 mRNA and protein with shorter survival time (P = 0.10 and P = 0.19). In addition, TNF-α induced CCA cell migration by the induction of transforming growth factor-β (TGF-β) resulting in ZEB2 and S100A4 mRNA and protein activation.

CONCLUSIONS

These studies demonstrate that TNF-α plays crucial role in the progression of CCA by activating TGF-β signaling and the induction of ZEB2 and S100A4, EMT-related proteins expression.

S100A2 protein and non-small cell lung cancer. The dual role concept

S100A2 is a member of the EF-hand motif family S100. Its role has been recently implicated in carcinogenesis and metastasis. Although its precise role in NSCLC patients is debated and conflicting results have been published, it has been associated with patient survival. S100A2 expression was downregulated in some studies while others disagree that S100A2 is strongly expressed in lung cancer. It has been recently published by Hountis et al. that there is a significant association between nuclear S100A2 positivity and better disease-free interval. Intensity of expression was the highest in the early and advanced stages, and equally distributed in the middle stages. This is indicative for a dual role of this protein in carcinogenesis. The expression of S100A2 in operable NSCLC varies widely, and this differential location and expression pattern (nuclear or cytoplasmic or both) seem to correlate with prognosis. The precise role for the movement of S100A2 protein between cytoplasm and nucleus is still unclear. We present here a literature review, and we propose the dual concept on its substantial role as a prognostic or predictive indicator in this unfavorable group of patients.

Histological Characterization of Biliary Intraepithelial Neoplasia with respect to Pancreatic Intraepithelial Neoplasia

Biliary intraepithelial neoplasia (BilIN) is a precursor lesion of hilar/perihilar and extrahepatic cholangiocarcinoma. BilIN represents the process of multistep cholangiocarcinogenesis and is the biliary counterpart of pancreatic intraepithelial neoplasia (PanIN). This study was performed to clarify the histological characteristics of BilIN in relation to PanIN. Using paraffin-embedded tissue sections of surgically resected specimens of cholangiocarcinoma associated with BilIN and pancreatic ductal adenocarcinoma associated with PanIN, immunohistochemical staining was performed using primary antibodies against MUC1, MUC2, MUC5AC, cyclin D1, p21, p53, and S100P. For mucin staining, Alcian blue pH 2.5 was used. Most of the molecules examined here showed similar expression patterns in BilIN and PanIN, in which their expression tended to increase along with the increase in atypia of the epithelial lesions. Significant differences were observed in the increase in mucin production and the expression of S100P in PanIN-1 and the expression of p53 in PanIN-3, when compared with those in BilIN of a corresponding grade. These results suggest that cholangiocarcinoma and pancreatic ductal adenocarcinoma share, at least in part, a common carcinogenic process and further confirm that BilIN can be regarded as the biliary counterpart of PanIN.

Immunohistochemical distinction between intrahepatic cholangiocarcinoma and pancreatic ductal adenocarcinoma

Distinction between primary intrahepatic cholangiocarcinoma (ICC) and metastatic pancreatic ductal adenocarcinoma (PDA) on a liver biopsy is essentially impossible histologically but has important clinical implications. In this study, 41 ICCs and 60 PDAs were immunohistochemically evaluated for the expression of S100P, pVHL, IMP3, maspin, MUC5AC, and CK17 proteins. The results showed pVHL expression in 29 (71%) ICCs but in only 3 (5%) PDAs. S100P, MUC5AC, and CK17 were frequently expressed in PDAs, seen in 57 (95%), 40 (67%), and 36 (60%) cases, respectively. In contrast, only 11 (27%), 5 (12%), and 5 (12%) ICC cases expressed these proteins. IMP3 was expressed in 37 (90%) ICC and 54 (90%) PDA cases with equal frequency. All 60 (100%) PDA and 30 (73%) ICC cases showed positive maspin immunoreactivity. A S100P-/pVHL+/MUC5AC-/CK17- staining pattern was essentially indicative of ICC, whereas the S100P+/pVHL-/MUC5AC+/CK17+ and S100P+/pVHL-/MUC5AC-/CK17+ staining patterns were suggestive of PDA. These observations demonstrate that S100P, pVHL, MUC5AC, and CK17 are a useful immunohistochemical panel that may help distinguish primary ICC from metastatic PDA.