Aims
Immune check‐point inhibitors are known to cause immune‐mediated adverse liver injury, but our knowledge is mainly based on cases treated with ipilimumab or nivolumab.
Methods and results
...Clinicopathological features of 10 patients with hepatobiliary adverse reactions caused by second‐generation drugs, pembrolizumab (n = 6) and atezolizumab (n = 4), were reviewed. Liver dysfunction developed during a median period of 3.5 weeks after administration of the check‐point inhibitor (3 days–1 year). Antinuclear antibodies were detected in two patients at a low titre (1/80), and serum IgG concentrations were also only mildly elevated in two patients. Liver biopsies showed panlobular hepatitis (n = 5), cholangiopathic changes (n = 2), granulomatous injury (n = 2) and bland cholestasis (n = 1). Two cases of cholangiopathy (both pembrolizumab‐treated) showed diffuse sclerosing cholangitis on imaging, and one also presented lymphocytic cholangitis resembling primary biliary cholangitis on biopsy. In two atezolizumab‐treated cases, Küpffer cells were hyperplastic and aggregated, forming microgranulomas. Confluent necrosis and eosinophilic or plasma cell infiltration were rare. On immunostaining, the ratio of CD8+/CD4+ cells was 12.2 ± 5.1, which was significantly higher than that in autoimmune hepatitis (2.7 ± 1.1; P < 0.001) or idiosyncratic drug‐induced liver injury (5.0 ± 1.1; P = 0.014). All patients responded to steroid therapy, but it was less effective in patients with sclerosing cholangitis.
Conclusions
Pembrolizumab and atezolizumab manifested not only lobular hepatitis but also sclerosing cholangitis, lymphocytic duct injury and granulomatous hepatitis, probably representing various impaired cellular functions in CD8+ lymphocytes and macrophages due to blockage of PD‐1–PD‐L1 interaction.
Cancer‐associated fibroblasts (CAFs), a major component of the tumor microenvironment (TME) in pancreatic ductal adenocarcinoma (PDAC), play an important role in tumorigenesis, metastasis, and ...chemoresistance. Tumor‐derived small extracellular vesicles (sEVs), which mediate cell‐to‐cell communication between cancer cells and fibroblasts, are also critical for cancer progression and metastasis. However, it remains unclear how PDAC cell‐derived sEVs activate fibroblasts, which contributes to tumor progression. Here, we report that ezrin (EZR) expression in PDAC cell‐derived sEVs (sEV‐EZR) can activate fibroblasts, resulting in increased migration ability and high expression of α‐SMA, PDGFRB, and high production of extracellular matrix in fibroblasts. Reciprocally, sEV‐EZR‐activated fibroblasts enhanced PDAC cell proliferation, invasion, and metastasis to the liver in animal models. Conversely, fibroblasts treated with PDAC cell‐derived sEVs with EZR knockdown resulted in the reduced metastatic ability of PDAC. Mechanistically, we demonstrated that PDAC cell‐derived sEV‐EZR increases the STAT3 and YAP‐1 signaling pathways to induce fibroblast activation, and the activated fibroblasts promote PDAC cell proliferation, invasion, and liver metastasis. Inhibition of the STAT3 and YAP‐1 signaling pathways by gene knockdown can abrogate sEV‐EZR‐induced effects. These findings suggest that targeting the interaction between PDAC cell‐derived sEV‐EZR and fibroblasts is a potential therapeutic strategy for PDAC.
PDAC cell‐derived sEVs can activate fibroblasts through activating STAT3 and YAP‐1 signaling, resulting in increased migration ability and high expression of α‐SMA, PDGFRB, and high production of extracellular matrix in fibroblasts. Reciprocally, sEV‐EZR‐activated fibroblasts enhanced PDAC cell proliferation, invasion, and metastasis to the liver. Inhibition of the STAT3 and YAP‐1 signaling pathways can abrogate sEV‐EZR‐induced effects. Thus, targeting sEV‐EZR may contribute to improve adjuvant PDAC therapies.
Hepatocellular carcinoma (HCC) is the fifth most common cancer and the second leading cause of cancer‐related deaths worldwide. Sarcomatoid HCC is a rare histological subtype of HCC with largely ...unclear clinical manifestations and outcomes. We evaluated the clinical manifestations and outcomes of patients with sarcomatoid HCC. We identified 5,047 patients with histologically proven HCC from the Cancer Registry Database (1996‐2016) of National Taiwan University Hospital. Among them, 40 patients with sarcomatoid HCC were identified from the pathology database of National Taiwan University Hospital. We included 160 patients with nonsarcomatoid HCC through propensity score matching according to sex, age, and Barcelona Clinic Liver Cancer stage. The majority of these patients with sarcomatoid HCC were men (75%); their median age was 58 years. Only 47.5% of the patients with sarcomatoid HCC presented with typical image patterns of HCC. The pathological grading of sarcomatoid HCC was more advanced compared with that of nonsarcomatoid HCC (42.5% vs. 23.8% in grade III and IV, P < 0.0001). The sarcomatoid group had significantly shorter median recurrence‐free (13.3 vs. 84.2 months, log‐rank P < 0.0001) and overall (8.3 vs. 69.3 months, log‐rank P < 0.0001) survival than did the nonsarcomatoid group. The results of the multivariable Cox proportional hazard model revealed histological sarcomatoid subtype as an independent factor for all‐cause mortality (hazard ratio HR, 6.47; 95% confidence interval CI, 3.12‐13.43; P < 0.0001) and tumor recurrence (HR, 4.08; 95% CI, 1.72‐9.66; P = 0.001). Conclusion: Compared with nonsarcomatoid HCC, sarcomatoid HCC was associated with more advanced histological grades and atypical image patterns. Histological sarcomatoid subtype is an independent predictor of tumor recurrence after curative treatment and all‐cause mortality in patients with HCC.
We investigated the utility of transient elastography (TE) for diagnosing biliary atresia (BA) in cholestatic infants and predicting the outcome of BA. Forty‐eight cholestatic infants (9‐87 days of ...age) with direct bilirubin level >1 mg/dL were enrolled. Liver stiffness measurement (LSM) by TE was performed during the cholestasis workup, and 15 subjects were diagnosed as BA. We assessed liver histology using liver biopsies from 36 subjects and graded fibrosis status using the METAVIR score. BA infants had significantly higher LSM values and METAVIR scores than non‐BA cholestatic infants. A receiver operating characteristic (ROC) curve analysis showed that an LSM >7.7 kPa was predictive of BA among cholestatic infants (sensitivity = 80%; specificity = 97%; area under the curve AUC = 85.3%; P = 0.0001). Cholestatic infants with an LSM >7.7 kPa were more likely to be diagnosed with BA (odds ratio OR = 128; P < 0.001). Very early measurement of LSM after hepatoportoenterostomy (HPE) is associated with occurrence of thrombocytopenia, splenomegaly, and esophageal varices 6 months post‐HPE. Five of the BA subjects were awaiting or had received liver transplantation (LT), and they had a significantly higher LSM measured 1 week post‐HPE than that in the other BA subjects (26.0 vs. 10.8 kPa; P = 0.006). A Cox proportional analysis demonstrated that the need for LT was significantly higher in BA subjects with LSM >16 kPa measured 1 week post‐HPE than other BA subjects (hazard ratio HR = 10.16; P = 0.04). Conclusion: LSM assessment during the workup of cholestatic infants may facilitate the diagnosis of BA. LSM post‐HPE may predict complications and the need for early LT in infants with BA. (Hepatology 2018).
G9a is a mammalian histone methyltransferase that contributes to the epigenetic silencing of tumor suppressor genes. Emerging evidence suggests that G9a is required to maintain the malignant ...phenotype, but the role of G9a function in mediating tumor metastasis has not been explored. Here, we show that G9a is expressed in aggressive lung cancer cells, and its elevated expression correlates with poor prognosis. RNAi-mediated knockdown of G9a in highly invasive lung cancer cells inhibited cell migration and invasion in vitro and metastasis in vivo. Conversely, ectopic G9a expression in weakly invasive lung cancer cells increased motility and metastasis. Mechanistic investigations suggested that repression of the cell adhesion molecule Ep-CAM mediated the effects of G9a. First, RNAi-mediated knockdown of Ep-CAM partially relieved metastasis suppression imposed by G9a suppression. Second, an inverse correlation between G9a and Ep-CAM expression existed in primary lung cancer. Third, Ep-CAM repression was associated with promoter methylation and an enrichment for dimethylated histone H3K9. G9a knockdown reduced the levels of H3K9 dimethylation and decreased the recruitment of the transcriptional cofactors HP1, DNMT1, and HDAC1 to the Ep-CAM promoter. Our findings establish a functional contribution of G9a overexpression with concomitant dysregulation of epigenetic pathways in lung cancer progression.
Genetic profiling studies on muscle-invasive bladder cancers (MIBCs) have discovered molecular subtypes with different biological characteristics. Immunohistochemical (IHC) markers such as GATA3, ...cytokeratin (CK) 20, CK5/6, and p53 are associated with these subtypes. In this study, we investigated the biological and prognostic significance of these IHC markers in MIBCs from 91 patients who underwent radical cystectomy. High Ki-67 indices were associated with negative CK20 (p = 0.002) and diffuse CK5/6 (p = 0.001) staining. By contrast, tumors with diffuse GATA3 expression had low Ki-67 index (p = 0.006). Regarding p53, three staining patterns were associated with a high Ki-67 index: (1) complete absence, (2) diffusely strong nuclear reactivity, and (3) diffusely strong cytoplasmic staining (p < 0.001 compared with other patterns). CK5/6 and CK20 expression was typically present in a reciprocal fashion; however, diffuse GATA3 and CK5/6 coexpression was observed in 13 (14.29%) cases. Among 78 chemotherapy-naïve patients, low GATA3 staining was associated with worse recurrence-free survival in both univariate (p = 0.008) and multivariate analyses (p = 0.002). CK20, CK5/6, or p53 expression was not associated with clinical outcome. Based on our results, IHC staining for GATA3 may help risk stratification in patients with MIBC receiving radical cystectomy. In addition, the differences in Ki-67 indices suggested that aberrant p53 expression was better defined by the three aforementioned patterns, rather than percentage of nuclear staining alone.
Identification of the primary site of cancer is essential for the treatment of patients with cancer. Numerous immunohistochemical markers have been developed to determine the differentiation of tumor ...cells and suggest possible primary sites, but markers of gastric and pancreatic adenocarcinomas are still lacking. Claudin-18 is a tight-junction protein uniquely expressed in gastric epithelial cells and has been shown to be expressed in gastric and pancreatic adenocarcinoma. Whether claudin-18 can be used as a marker for identifying the primary site of cancer is still unclear. In this study, we used the immunohistochemical method to stain claudin-18 in tissue arrays containing 575 carcinomas from different anatomic sites and representative sections of 157 metastatic adenocarcinomas. In the group of primary tumors, claudin-18 was frequently expressed in gastric, pancreatic, and pulmonary mucinous adenocarcinomas. Half of cholangiocarcinomas and ovarian mucinous carcinomas and some colorectal and pulmonary adenocarcinomas were also positive for claudin-18. In the metastatic cohort, 15 of 17 (88%) gastric adenocarcinomas, 18 of 23 (78%) pancreatic adenocarcinomas, and 4 of 7 (57%) cholangiocarcinomas and gallbladder adenocarcinomas were positive for claudin-18. Only 4 tumors that originated outside the stomach and pancreatobiliary tract were positive for claudin-18. After normalization to the tumor frequency, the sensitivity of claudin-18 for identifying the stomach and pancreatobiliary tract as primary tumor sites was 79%, and the specificity was 93%. The positive and negative predictive values were 76% and 94%, respectively. In conclusion, claudin-18 represents a sensitive and specific marker for stomach and pancreatobiliary adenocarcinoma that may be a useful diagnostic tool in routine surgical pathology.
Soft-tissue sarcomas represent a heterogeneous group of cancer, with more than 50 histological subtypes
. The clinical presentation of patients with different subtypes is often atypical, and ...responses to therapies such as immune checkpoint blockade vary widely
. To explain this clinical variability, here we study gene expression profiles in 608 tumours across subtypes of soft-tissue sarcoma. We establish an immune-based classification on the basis of the composition of the tumour microenvironment and identify five distinct phenotypes: immune-low (A and B), immune-high (D and E), and highly vascularized (C) groups. In situ analysis of an independent validation cohort shows that class E was characterized by the presence of tertiary lymphoid structures that contain T cells and follicular dendritic cells and are particularly rich in B cells. B cells are the strongest prognostic factor even in the context of high or low CD8
T cells and cytotoxic contents. The class-E group demonstrated improved survival and a high response rate to PD1 blockade with pembrolizumab in a phase 2 clinical trial. Together, this work confirms the immune subtypes in patients with soft-tissue sarcoma, and unravels the potential of B-cell-rich tertiary lymphoid structures to guide clinical decision-making and treatments, which could have broader applications in other diseases.
On the basis of morphological features, we subclassified 189 intrahepatic cholangiocarcinomas into two subtypes: bile duct and cholangiolar. The cholangiolar type is composed of cuboidal to low ...columnar tumor cells that contain scanty cytoplasm. The bile duct type is composed of tall columnar tumor cells arranged in a large glandular pattern. In this study, 77 (41%) tumors were classified as the cholangiolar type and 112 (59%) tumors were classified as the bile duct type. The cholangiolar-type intrahepatic cholangiocarcinoma was more frequently associated with viral hepatitis, whereas all but one intrahepatic cholangiocarcinoma associated with intrahepatic lithiasis were classified as the bile duct type. Biliary intraepithelial neoplasm or intraductal papillary neoplasm of the bile duct could be identified in 50 bile duct-type intrahepatic cholangiocarcinomas (45%), but in only 3 cholangiolar-type intrahepatic cholangiocarcinomas (4%). Cholangiolar-type intrahepatic cholangiocarcinomas frequently expressed N-cadherin, whereas bile duct intrahepatic cholangiocarcinomas were more likely to express S100P, Trefoil factor 1, and anterior gradient 2. KRAS is mutated in 23 of 98 (23%) bile duct-type intrahepatic cholangiocarcinomas and in only 1 of 76 (1%) cholangiolar-type intrahepatic cholangiocarcinomas. Cholangiolar-type intrahepatic cholangiocarcinomas had a higher frequency of IDH1 or 2 mutations than did the bile duct-type intrahepatic cholangiocarcinomas. The molecular features of the bile duct-type intrahepatic cholangiocarcinoma were similar to those of hilar cholangiocarcinoma. Patients with the cholangiolar-type intrahepatic cholangiocarcinoma had higher 5-year survival rates than those of patients with the bile duct-type intrahepatic cholangiocarcinoma. Our results indicated that intrahepatic cholangiocarcinoma was a heterogeneous tumor. Subclassification of intrahepatic cholangiocarcinomas based on cholangiocytic differentiation divides them into two groups with different etiologies, clinical manifestations, and molecular pathogeneses.
KRAS mutations are the earliest events found in approximately 90% of pancreatic ductal adenocarcinomas (PDACs). However, little is known as to why KRAS mutations preferentially occur in PDACs and ...what processes/factors generate these mutations. While abnormal carbohydrate metabolism is associated with a high risk of pancreatic cancer, it remains elusive whether a direct relationship between KRAS mutations and sugar metabolism exists. Here, we show that under high-glucose conditions, cellular O-GlcNAcylation is significantly elevated in pancreatic cells that exhibit lower phosphofructokinase (PFK) activity than other cell types. This post-translational modification specifically compromises the ribonucleotide reductase (RNR) activity, leading to deficiency in dNTP pools, genomic DNA alterations with KRAS mutations, and cellular transformation. These results establish a mechanistic link between a perturbed sugar metabolism and genomic instability that induces de novo oncogenic KRAS mutations preferentially in pancreatic cells.
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•Pancreatic cells exhibit lower phosphofructokinase activity than other cell types•High glucose elevates O-GlcNAcylation and genomic alterations in pancreatic cells•Reduction of RNR activity leads to nucleotide pool imbalance and KRAS mutations•PFK activity alters the sensitivity to high-glucose-induced genomic effects
Most pancreatic ductal adenocarcinomas contain activated KRAS mutations required for cancer initiation and maintenance. Here, Hu et al. show that high glucose promotes O-GlcNAcylation on ribonucleotide reductase, leading to nucleotide pool imbalance and KRAS mutations preferentially in pancreatic cells.
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