Deep Learning-Enabled Diagnosis of Liver Adenocarcinoma

BACKGROUND & AIMS

Diagnosis of adenocarcinoma in the liver is a frequent scenario in routine pathology and has a critical impact on clinical decision making. However, rendering a correct diagnosis can be challenging, and often requires the integration of clinical, radiologic, and immunohistochemical information. We present a deep learning model (HEPNET) to distinguish intrahepatic cholangiocarcinoma from colorectal liver metastasis, as the most frequent primary and secondary forms of liver adenocarcinoma, with clinical grade accuracy using H&E-stained whole-slide images.

METHODS

HEPNET was trained on 714,589 image tiles from 456 patients who were randomly selected in a stratified manner from a pool of 571 patients who underwent surgical resection or biopsy at Heidelberg University Hospital. Model performance was evaluated on a hold-out internal test set comprising 115 patients and externally validated on 159 patients recruited at Mainz University Hospital.

RESULTS

On the hold-out internal test set, HEPNET achieved an area under the receiver operating characteristic curve of 0.994 (95% CI, 0.989-1.000) and an accuracy of 96.522% (95% CI, 94.521%-98.694%) at the patient level. Validation on the external test set yielded an area under the receiver operating characteristic curve of 0.997 (95% CI, 0.995-1.000), corresponding to an accuracy of 98.113% (95% CI, 96.907%-100.000%). HEPNET surpassed the performance of 6 pathology experts with different levels of experience in a reader study of 50 patients (P = .0005), boosted the performance of resident pathologists to the level of senior pathologists, and reduced potential downstream analyses.

CONCLUSIONS

We provided a ready-to-use tool with clinical grade performance that may facilitate routine pathology by rendering a definitive diagnosis and guiding ancillary testing. The incorporation of HEPNET into pathology laboratories may optimize the diagnostic workflow, complemented by test-related labor and cost savings.

Caspase-8 in endothelial cells maintains gut homeostasis and prevents small bowel inflammation in mice

The gut has a specific vascular barrier that controls trafficking of antigens and microbiota into the bloodstream. However, the molecular mechanisms regulating the maintenance of this vascular barrier remain elusive. Here, we identified Caspase-8 as a pro-survival factor in mature intestinal endothelial cells that is required to actively maintain vascular homeostasis in the small intestine in an organ-specific manner. In particular, we find that deletion of Caspase-8 in endothelial cells results in small intestinal hemorrhages and bowel inflammation, while all other organs remained unaffected. We also show that Caspase-8 seems to be particularly needed in lymphatic endothelial cells to maintain gut homeostasis. Our work demonstrates that endothelial cell dysfunction, leading to the breakdown of the gut-vascular barrier, is an active driver of chronic small intestinal inflammation, highlighting the role of the intestinal vasculature as a safeguard of organ function.

Transforming Growth Factor-β Activated Kinase 1 (Tak1) Is Activated in Hepatocellular Carcinoma, Mediates Tumor Progression, and Predicts Unfavorable Outcome

Simple Summary

Chronic inflammation is known to drive cancer initiation and progression in the liver and other organs. In different genetic mouse models, the role of the pro-inflammatory kinase Tak1 in liver cancer development has been controversial so far. To clarify the role of Tak1 in human hepatocellular carcinoma (HCC), we investigated the expression of Tak1 in a large and clinicopathologically well-characterized patient cohort with HCC. In human livers and HCCs, Tak1 is predominantly present in its isoform Tak1A localizing to the cell nucleus. Tak1 is upregulated in HCCs of the diethylnitrosamine mouse model as well as in human HCCs, independent of etiology, and is further induced in distant metastases. Overexpression of the isoform Tak1A in the HCC cell line Huh7 resulted in increased tumor cell migration, whereas overexpression of full-length Tak1 had no significant effect. In human HCCs, high nuclear Tak1 expression is associated with vascular invasion and short overall survival.

Abstract

Although knowledge on inflammatory signaling pathways driving cancer initiation and progression has been increasing, molecular mechanisms in hepatocarcinogenesis are still far from being completely understood. Hepatocyte-specific deletion of the MAPKKK Tak1 in mice recapitulates important steps of hepatocellular carcinoma (HCC) development, including the occurrence of cell death, steatohepatitis, dysplastic nodules, and HCCs. However, overactivation of Tak1 in mice upon deletion of its deubiquitinase Cyld also results in steatohepatitis and HCC development. To investigate Tak1 and Cyld in human HCCs, we created a tissue microarray to analyze their expression by immunohistochemistry in a large and well-characterized cohort of 871 HCCs of 561 patients. In the human liver and HCC, Tak1 is predominantly present as its isoform Tak1A and predominantly localizes to cell nuclei. Tak1 is upregulated in diethylnitrosamine-induced mouse HCCs as well as in human HCCs independent of etiology and is further induced in distant metastases. A high nuclear Tak1 expression is associated with short survival and vascular invasion. When we overexpressed Tak1A in Huh7 cells, we observed increased tumor cell migration, whereas overexpression of full-length Tak1 had no significant effect. A combined score of low Cyld and high Tak1 expression was an independent prognostic marker in a multivariate Cox regression model.

Completion rate and impact on physician-patient relationship of video consultations in medical oncology: a randomised controlled open-label trial

Background

Mobile phone video call applications generally did not undergo testing in randomised controlled clinical trials prior to their implementation in patient care regarding the rate of successful patient visits and impact on the physician–patient relationship.

Methods

The National Center for Tumour Diseases (NCT) MOBILE trial was a monocentric open-label randomised controlled clinical trial of patients with solid tumours undergoing systemic cancer therapy with need of a follow-up visit with their consulting physician at outpatient clinics. 66 patients were 1:1 randomised to receive either a standard in-person follow-up visit at outpatient clinics or a video call via a mobile phone application. The primary outcome was feasibility defined as the proportion of patients successfully completing the first follow-up visit. Secondary outcomes included success rate of further video calls, time spent by patient and physician, patient satisfaction and quality of physician–patient relationship.

Findings

Success rate of the first follow-up visit in the intention-to-treat cohort was 87.9% (29 of 33) for in-person visits and 78.8% (26 of 33) for video calls (relative risk: RR 0.90, 95% CI 0.70 to 1.13, p=0.51). The most common reasons for failure were software incompatibility in the video call and no-show in the in-person visit arm. The success rate for further video visits was 91.7% (11 of 12). Standardised patient questionnaires showed significantly decreased total time spent and less direct costs for patients (Δmean −170.8 min, 95% CI −246 min to −95.5 min), p<0.0001; Δmean −€14.37, 95% CI −€23.9 to −€4.8, p<0.005) and comparable time spent for physicians in the video call arm (Δmean 0.5 min, 95% CI −5.4 min to 6.4 min, p=0.86). Physician–patient relationship quality mean scores assessed by a validated standardised questionnaire were higher in the video call arm (1.13-fold, p=0.02).

Interpretation

Follow-up visits with the tested mobile phone video call application were feasible but software compatibility should be critically evaluated.

Trial registration number

DRKS00015788.

Knockdown of Atg7 Induces Nuclear-LC3 Dependent Apoptosis and Augments Chemotherapy in Colorectal Cancer Cells

Autophagy is a catabolic process that enables cells to degrade obsolete content and refuel energy depots. In colorectal cancer (CRC) autophagy has been shown to promote tumorigenesis through energy delivery in the condition of uncontrolled proliferation. With this study, we aimed at evaluating whether autophagy sustains CRC cell viability and if it impacts therapy resistance. Initially, a colorectal cancer tissue micro array, containing mucosa (n = 10), adenoma (n = 18) and adenocarcinoma (n = 49) spots, was stained for expression of essential autophagy proteins LC3b, Atg7, p62 and Beclin-1. Subsequently, central autophagy proteins were downregulated in CRC cells using siRNA technology. Viability assays, flow cytometry and immunoblotting were performed and three-dimensional cell culture was utilized to study autophagy in a tissue mimicking environment. In our study we found an upregulation of Atg7 in CRC. Furthermore, we identified Atg7 as crucial factor within the autophagy network for CRC cell viability. Its disruption induced cell death via triggering apoptosis and in combination with conventional chemotherapy it exerted synergistic effects in inducing CRC cell death. Cell death was strictly dependent on nuclear LC3b, since simultaneous knockdown of Atg7 and LC3b completely restored viability. This study unravels a novel cell death preventing function of Atg7 in interaction with LC3b, thereby unmasking a promising therapeutic target in CRC.

Nuclear Translocation of RELB Is Increased in Diseased Human Liver and Promotes Ductular Reaction and Biliary Fibrosis in Mice

BACKGROUND & AIMS

Cholangiocyte proliferation and ductular reaction contribute to the onset and progression of liver diseases. Little is known about the role of the transcription factor nuclear factor-κB (NF-κB) in this process. We investigated the activities of the RELB proto-oncogene NF-κB subunit in human cholangiocytes and in mouse models of liver disease characterized by a ductular reaction.

METHODS

We obtained liver tissue samples from patients with primary sclerosing cholangitis, primary biliary cholangitis, hepatitis B or C virus infection, autoimmune hepatitis, alcoholic liver disease, or without these diseases (controls) from a tissue bank in Germany. Tissues were analyzed by immunohistochemistry for levels of RELB and lymphotoxin β (LTB). We studied mice with liver parenchymal cell (LPC)-specific disruption of the cylindromatosis (CYLD) lysine 63 deubiquitinase gene (Cyld), with or without disruption of Relb (Cyld^ΔLPC mice and Cyld/Relb^ΔLPC mice) and compared them with C57BL/6 mice (controls). Mice were fed 5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) or standard chow diets to induce biliary injury or were given injections of CCl₄ to induce non-cholestatic liver fibrosis. Liver tissues were analyzed by histology, immunohistochemistry, immunoblots, in situ hybridization, and quantitative real-time polymerase chain reaction. Cholangiocytes were isolated from normal human liver, incubated with LTB receptor agonist, and transfected with small interfering RNAs to knock down RELB.

RESULTS

In liver tissues from patients with primary sclerosing cholangitis, primary biliary cholangitis, chronic infection with hepatitis B or C virus, autoimmune hepatitis, or alcoholic liver disease, we detected increased nuclear translocation of RELB and increased levels of LTB in cholangiocytes that formed reactive bile ducts compared with control liver tissues. Human cholangiocytes, but not those with RELB knockdown, proliferated with exposure to LTB. The phenotype of Cyld^ΔLPC mice, which included ductular reaction, oval cell activation, and biliary fibrosis, was completely lost from Cyld/Relb^ΔLPC mice. Compared with livers from control mice, livers from Cyld^ΔLPC mice (but not Cyld/Relb^ΔLPC mice) had increased levels of mRNAs encoding cytokines (LTB; CD40; and tumor necrosis factor superfamily [TNFSF] members TNFSF11 [RANKL], TNFSF13B [BAFF], and TNFSF14 [LIGHT]) produced by reactive cholangiocytes. However, these strains of mice developed similar levels of liver fibrosis in response to CCl₄ exposure. Cyld^ΔLPC mice and Cyld/Relb^ΔLPC mice had improved liver function on the DDC diet compared with control mice fed the DDC diet.

CONCLUSION

Reactive bile ducts in patients with chronic liver diseases have increased levels of LTB and nuclear translocation of RELB. RELB is required for the ductular reaction and development of biliary fibrosis in Cyld^ΔLPC mice. Deletion of RELB and CYLD from LPCs protects mice from DDC-induced cholestatic liver fibrosis.

An undifferentiated carcinoma at Klatskin-position with long-term complete remission after chemotherapy

Background

Neoplasms anatomically adjacent to the bile duct usually derive from malignantly transformed cholangiocytes forming cholangiocarcinoma (CCA). CCAs are divided in extrahepatic (eCCA) and intrahepatic (iCCA) tumors. Patients with irresectable CCAs are treated with systemic chemotherapy and have an unfavorable prognosis with a median survival of about one year. Here, we report a case of an undifferentiated carcinoma in Klatskin-position with long-term remission after systemic chemotherapy.

Case Presentation

A 65-year-old Caucasian male presented with painless jaundice caused by an undifferentiated carcinoma in Klatskin-position (Type IIIb). Alpha fetoprotein (AFP; 3675 IU/mL) and carbohydrate antigen 19-9 (CA 19-9; 183 U/ml) were elevated. An exploratory laparotomy was carried out, but the patient was found to be irresectable due to severe fibrosis caused by biliary obstruction. Histology showed an undifferentiated carcinoma with high proliferation rate, and the patient was therefore subjected to poly-chemotherapy treatment according to the FOLFOX6-protocol. During therapy, AFP decreased to normal. Subsequent CT scans and ERC revealed a complete remission. Four years past initial diagnosis, a new suspicious lesion in the liver is visible on MRT; however, AFP and CA 19-9 are still in the normal range.

Conclusions

Our case demonstrates that histopathological defined diagnosis may significantly inform therapeutic decision-making in irresectable cholangiocarcinoma even in regard to conventional systemic therapy. In case of an undifferentiated carcinoma poly-chemotherapy may provide significant success.

Venetoclax (ABT-199) Might Act as a Perpetrator in Pharmacokinetic Drug-Drug Interactions

Venetoclax (ABT-199) represents a specific B-cell lymphoma 2 (Bcl-2) inhibitor that is currently under development for the treatment of lymphoid malignancies. So far, there is no published information on its interaction potential with important drug metabolizing enzymes and drug transporters, or its efficacy in multidrug resistant (MDR) cells. We therefore scrutinized its drug-drug interaction potential in vitro. Inhibition of cytochrome P450 enzymes (CYPs) was quantified by commercial kits. Inhibition of drug transporters (P-glycoprotein (P-gp, ABCB1), breast cancer resistance protein (BCRP), and organic anion transporting polypeptides (OATPs)) was evaluated by the use of fluorescent probe substrates. Induction of drug transporters and drug metabolizing enzymes was quantified by real-time RT-PCR. The efficacy of venetoclax in MDR cells lines was evaluated with proliferation assays. Venetoclax moderately inhibited P-gp, BCRP, OATP1B1, OATP1B3, CYP3A4, and CYP2C19, whereas CYP2B6 activity was increased. Venetoclax induced the mRNA expression of CYP1A1, CYP1A2, UGT1A3, and UGT1A9. In contrast, expression of ABCB1 was suppressed, which might revert tumor resistance towards antineoplastic P-gp substrates. P-gp over-expression led to reduced antiproliferative effects of venetoclax. Effective concentrations for inhibition and induction lay in the range of maximum plasma concentrations of venetoclax, indicating that it might act as a perpetrator drug in pharmacokinetic drug-drug interactions.

Obatoclax as a perpetrator in drug-drug interactions and its efficacy in multidrug resistance cell lines

OBJECTIVES

Obatoclax is a pan-Bcl-2 inhibitor with promising efficacy, especially when combined with other antineoplastic agents. Pharmacokinetic drug-drug interactions can occur systemically and at the level of the tumour cell. Thus, this study scrutinised the interaction potential of obatoclax in vitro.

METHODS

Obatoclax was screened for P-gp inhibition by calcein assay, for breast cancer resistance protein (BCRP) inhibition by pheophorbide A assay and for inhibition of cytochrome P450 isoenzymes (CYPs) by commercial kits. Induction of mRNA of drug-metabolising enzymes and drug transporters was quantified in LS180 cells via real-time polymerase chain reaction and involvement of nuclear receptors was assessed by reporter gene assays. Proliferation assays were used to assess whether obatoclax retains its efficacy in cell lines overexpressing BCRP, P-glycoprotein (P-gp) or multidrug resistance-associated protein 2 (MRP2).

KEY FINDINGS

Obatoclax induced the mRNA expression of several genes (e.g. CYP1A1, CYP1A2 and ABCG2 (five to seven-fold) through activation of the aryl hydrocarbon receptor in the nanomolar range. Obatoclax inhibits P-gp, BCRP and some CYPs at concentrations exceeding plasma levels. P-gp, MPR2 or BCRP overexpression did not influence the efficacy of obatoclax.

CONCLUSIONS

Obatoclax retains its efficacy in cells overexpressing P-gp, MRP2 or BCRP and might act as a perpetrator drug in interactions with drugs, for example being substrates of CYP1A2 or BCRP.

Down-regulation of CYLD as a trigger for NF-κB activation and a mechanism of apoptotic resistance in hepatocellular carcinoma cells

The cylindromatosis gene (CYLD) was identified as a tumor suppressor gene, which is mutated in familial cylindromatosis (Brooke-Spiegler syndrome), an autosomal-dominant predisposition to multiple tumors of the skin appendages. CYLD is a deubiquitinating enzyme acting as a negative regulator of the nuclear factor κB (NF-κB) signaling pathway by removing lysine-63-linked polyubiquitin chains from NF-κB activating proteins. In order to investigate the role of CYLD in apoptotic signaling in human hepatocellular carcinoma (HCC) cells, we first studied the expression levels of CYLD in HCC tissues. CYLD expression was lower in HCC both at protein and mRNA levels compared to the surrounding non-malignant tissue. In order to further study the role of CYLD in the apoptotic sensitivity of HCC cells, CYLD was specifically down-regulated in HCC cell lines via RNA interference. The specific down-regulation of CYLD resulted in increased resistance towards treatment with doxorubicin, 5-fluorouracil and cisplatin. In addition, the down-regulation of CYLD in HCC cells decreased the sensitivity towards tumor necrosis factor-α-induced apoptosis. The CYLD knockdown also led to the degradation of the NF-κB inhibitor, IκB-α, resulting in enhanced NF-κB activity in HCC cells. Finally, we found that CYLD expression was triggered by the multikinase inhibitor, sorafenib, by the inhibition of Raf-1, as well as by the blockage of the pro-survival kinases, MEK (U0126) and the epidermal growth factor receptor (AG1478). In summary, we show that CYLD is down-regulated in human HCC and is involved in the apoptotic resistance of HCC cells. Our data identify the reconstitution of CYLD expression as an attractive approach for overcoming resistance to treatment in HCC.