miRNA profiling of biliary intraepithelial neoplasia reveals stepwise tumorigenesis in distal cholangiocarcinoma via the miR-451a/ATF2 axis.

Distal cholangiocarcinoma (dCCA) is a biliary tract cancer with a dismal prognosis and is often preceded by biliary intraepithelial neoplasia (BilIN), representing the most common biliary non-invasive precursor lesion. BilIN are histologically well defined but have not so far been characterised systematically at the molecular level. The aim of this study was to determine miRNA-regulated genes in cholangiocarcinogenesis via BilIN. We used a clinicopathologically well-characterised cohort of 12 dCCA patients. Matched samples of non-neoplastic biliary epithelia, BilIN and invasive tumour epithelia of each patient were isolated from formalin-fixed paraffin-embedded tissue sections by laser microdissection. The resulting 36 samples were subjected to total RNA extraction and the expression of 798 miRNAs was assessed using the Nanostring® technology. Candidate miRNAs were validated by RT-qPCR and functionally investigated following lentiviral overexpression in dCCA-derived cell lines. Potential direct miRNA target genes were identified by microarray and prediction algorithms and were confirmed by luciferase assay. We identified 49 deregulated miRNAs comparing non-neoplastic and tumour tissue. Clustering of these miRNAs corresponded to the three stages of cholangiocarcinogenesis, supporting the concept of BilIN as a tumour precursor. Two downregulated miRNAs, i.e. miR-451a (-10.9-fold down) and miR-144-3p (-6.3-fold down), stood out by relative decrease. Functional analyses of these candidates revealed a migration inhibitory effect in dCCA cell lines. Activating transcription factor 2 (ATF2) and A disintegrin and metalloproteinase domain-containing protein 10 (ADAM10) were identified as direct miR-451a target genes. Specific ATF2 inhibition by pooled siRNAs reproduced the inhibitory impact of miR-451a on cancer cell migration. Thus, our data support the concept of BilIN as a direct precursor of invasive dCCA at the molecular level. In addition, we identified miR-451a and miR-144-3p as putative tumour suppressors attenuating cell migration by inhibiting ATF2 in the process of dCCA tumorigenesis. © The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

DMBT1 expression in biliary carcinogenesis with correlation of clinicopathological data.

AIMS: Deleted in malignant brain tumours 1 (DMBT1) exerts functions in the regulation of epithelial differentiation and inflammation and has been proposed as a tumour suppressor. Because chronic inflammation is a hallmark of cholangiocarcinogenesis, the aim of this study was to investigate the expression of DMBT1 in biliary tract cancer (BTC) and to correlate this expression with clinicopathological data. METHODS AND RESULTS: The expression of DMBT1 protein was examined immunohistochemically in 157 BTC patients [41 intrahepatic (ICC), 60 extrahepatic cholangiocarcinomas (ECC) and 56 adenocarcinomas of the gallbladder (GBAC)]. Additionally, 56 samples of high-grade biliary intraepithelial neoplasia (BilIN 3) and 92 corresponding samples of histological non-neoplastic biliary tract tissues were included. DMBT1 expression was increased significantly in BilIN 3 compared to normal tissue (P < 0.0001) and BTC (P < 0.0001). BTC showed no significant difference in DMBT1 expression compared to non-neoplastic biliary tissue (P = 0.315). Absent DMBT1 expression in non-neoplastic biliary tissue of BTC patients was associated with poorer survival (P = 0.027). DMBT1 expression was correlated significantly with patients' age (P < 0.001). CONCLUSION: DMBT1 is expressed differently in cholangiocarcinogenesis and poorer patients' survival rates are associated with absent DMBT1 expression in non-neoplastic biliary tissue, suggesting a tumour-suppressive role of DMBT1 in early cholangiocarcinogenesis.

Programmed Death Ligand-1 (PD-L1) Is an Independent Negative Prognosticator in Western-World Gallbladder Cancer.

Inhibition of the programmed cell death protein-1/ligand-1 (PD-1/PD-L1) axis has opened a new era in the treatment of solid cancers. However, there is no data on the expression and relevance of PD-L1 in Western gallbladder cancer (GBC). We assessed PD-L1 immunohistochemically in 131 GBC patients as Tumor Proportion Score (TPS), Immune Cell Score (IC) and Combined Positivity Score (CPS). Tumor cells expressed PD-L1 in a subset of 14.7% GBC patients at a TPS cut-off of 1%. Higher PD-L1 levels above 10% and 25% TPS were reached in 4.7% and 3.1% of GBC cases, respectively. At a 10% cut-off, TPS was associated with distinct histomorphological subtypes and correlated with poor tumor differentiation. Survival analysis revealed a TPS above 10% to be a highly significant and independent negative prognosticator in GBC. PD-L1 expression was associated with increased CD4+, CD8+ and PD-1+ immune cell densities. In 14.8% of the cases, scattered immune cells expressed T-cell immunoreceptor with Ig and ITIM domains (TIGIT), which was correlated to tumoral expression of its ligand CD155. We here show that a high PD-L1 expression confers a negative prognostic value in Western-world GBC and highlight the TIGIT/CD155 immune checkpoint as a potential new target for GBC immunotherapy.

The Transmembrane Receptor TIRC7 Identifies a Distinct Subset of Immune Cells with Prognostic Implications in Cholangiocarcinoma.

Cholangiocarcinoma (CCA) is a heterogeneous malignancy with a dismal prognosis. Therapeutic options are largely limited to surgery and conventional chemotherapy offers limited benefit. As immunotherapy has proven highly effective in various cancer types, we have undertaken a quantitative immunohistopathological assessment of immune cells expressing the immunoinhibitory T cell immune response cDNA 7 receptor (TIRC7), an emerging immunoinhibitory receptor, in a cohort of 135 CCA patients. TIRC7+ immune cells were present in both the tumor epithelia and stroma in the majority of CCA cases with the highest levels found in intrahepatic CCA. While intraepithelial density of TIRC7+ immune cells was decreased compared to matched non-neoplastic bile ducts, stromal quantity was higher in the tumor samples. Tumors exhibiting signet ring cell or adenosquamous morphology were exclusively associated with an intraepithelial TIRC7+ phenotype. Survival analysis showed intraepithelial TIRC7+ immune cell density to be a highly significant favorable prognosticator in intrahepatic but not proximal or distal CCA. Furthermore, intraepithelial TIRC7+ immune cell density correlated with the number of intraepithelial CD8+ immune cells and with the total number of CD4+ immune cells. Our results suggest the presence and prognostic relevance of TIRC7+ immune cells in CCA and warrant further functional studies on its pharmacological modulation.

Pathologic fractures in patients with multiple myeloma undergoing bisphosphonate therapy: incidence and correlation with course of disease.

OBJECTIVE: The purposes of this study were single-center analysis of the incidence of pathologic fractures in patients with multiple myeloma undergoing bisphosphonate therapy and correlation of the occurrence of pathologic fractures with the course of disease. MATERIALS AND METHODS: One hundred ninety-one patients with multiple myeloma consecutively underwent unenhanced whole-body low-dose MDCT in parallel with hematologic follow-up. Only patients undergoing at least two whole-body low-dose MDCT examinations were included in this retrospective study, resulting in 561 survey intervals. The median analysis period per patient was 23 months (range, 3-53 months). Fracture incidence and the relation between newly occurring fractures and course of the disease were assessed. RESULTS: Forty-nine pathologic fractures were detected in 49 of the 561 survey intervals (8.7%) and in 36 of the 191 patients (19%). Fractures were found on MDCT images irrespective of disease course. They were found in 25 of 202 intervals (12.4%) of progressive disease, in 14 of 171 intervals (8.2%) of disease remission, and in 10 of 188 intervals (5.3%) of stable disease. The overall calculated annual incidence of pathologic fractures in patients with multiple myeloma was 14%. Eleven patients had more than one fracture, all of which were vertebral compression fractures. Three patients had three episodes of bone fracture, and eight patients had two episodes. CONCLUSION: Pathologic fractures in patients with multiple myeloma undergoing bisphosphonate therapy occur independently of myeloma activity and therefore should not be considered a sign of disease progression.

Accuracy of serum LDH elevation for the diagnosis of Pneumocystis jiroveci pneumonia.

In 328 immunocompromised patients, 105 with and 193 without Pneumocystis jiroveci pneumonia (PCP), serum lactate dehydrogenase (LDH) was analysed retrospectively, taking into consideration the time interval from the onset of symptoms to the start of specific therapy. 97 of the 105 PCP patients were negative for human immunodeficiency virus (HIV). Eight were positive. Of the 193 patients without PCP 134 were HIV-negative and 59 were HIV-positive. In HIV-negative patients the sensitivity of LDH elevation was 63% and specificity 43%. In HIV-positive patients sensitivity was 100% and specificity 47%. The overall accuracy of LDH for the diagnosis of PCP was 52%, 51% in HIV-negative and 58% in HIV-positive patients. Except for its sensitivity in HIV-positive patients, the value of LDH for the diagnosis of PCP should not be overestimated.