Expert Consensus on Pathological Diagnosis of Intrahepatic Cholangiocarcinoma (2022 version)

Molecular structure and enzymatic mechanism of the human collagen hydroxylysine galactosyltransferase GLT25D1/COLGALT1

During collagen biosynthesis, lysine residues undergo extensive post-translational modifications through the alternate action of two distinct metal ion-dependent enzyme families (i.e., LH/PLODs and GLT25D/COLGALT), ultimately producing the highly conserved α-(1,2)-glucosyl-β-(1,O)-galactosyl-5-hydroxylysine pattern. Malfunctions in these enzymes are linked to developmental pathologies and extracellular matrix alterations associated to enhanced aggressiveness of solid tumors. Here, we characterized human GLT25D1/COLGALT1, revealing an elongated head-to-head homodimeric assembly. Each monomer encompasses two domains (named GT1 and GT2), both unexpectedly capable of binding metal ion cofactors and UDP-α-galactose donor substrates, resulting in four candidate catalytic sites per dimer. We identify the catalytic site in GT2, featuring an unusual Glu-Asp-Asp motif critical for Mn2+ binding, ruling out direct catalytic roles for the GT1 domain, but showing that in this domain the unexpectedly bound Ca2+ and UDP-α-galactose cofactors are critical for folding stability. Dimerization, albeit not essential for GLT25D1/COLGALT1 activity, provides a critical molecular contact site for multi-enzyme assembly interactions with partner multifunctional LH/PLOD lysyl hydroxylase-glycosyltransferase enzymes.

A novel hypoxia-induced lncRNA, SZT2-AS1, boosts HCC progression by mediating HIF heterodimerization and histone trimethylation under a hypoxic microenvironment

Hypoxic microenvironment plays a critical role in solid tumor growth, metastasis and angiogenesis. Hypoxia-inducible factors (HIFs), which are canonical transcription factors in response to hypoxia, are stabilized under hypoxia and coordinate the process of hypoxia-induced gene expression, leading to cancer progression. Increasing evidence has uncovered that long noncoding RNAs (lncRNAs), which are closely associated with cancer, play crucial roles in hypoxia-mediated HCC progression, while the mechanisms are largely unknown. Here, we identified SZT2-AS1 as a novel lncRNA in HCC, which was induced by hypoxia in a HIF-1-dependent manner and promoted HCC growth, metastasis and angiogenesis both in vitro and in vivo. And SZT2-AS1 also mediated the hypoxia-induced HCC progression. Clinical data indicated that SZT2-AS1 level was substantially increased in HCC and closely associated with poor clinical outcomes, acting as an independent prognostic predictor. Mechanistically, SZT2-AS1 recruited HIF-1α and HIF-1β to form the HIF-1 heterodimer, and it was required for the occupancy of HIF-1 to hypoxia response elements (HREs) and HIF target gene transcription. In addition, SZT2-AS1 was required for hypoxia-induced histone trimethylation (H3K4me3 and H3K36me3) at HREs. Through recruiting methyltransferase SMYD2, SZT2-AS1 promoted trimethylation of H3K4 and H3K36 in HCC cells. Taken together, our results uncovered a lncRNA-involved positive feedback mechanism under hypoxia and established the clinical value of SZT2-AS1 in prognosis and as a potential therapeutic target in HCC.

Histopathologic Grading of Residual Tumor Predicts Survival of Intrahepatic Cholangiocarcinoma Patients Treated With Neoadjuvant Therapy: Major Pathologic Response and Its Clinical Significance

Neoadjuvant therapy (NAT) is increasingly used to treat patients with initially unresectable intrahepatic cholangiocarcinoma (iCCA). A histopathologic grading system for residual tumors that can predict patient survival is lacking in the literature. This retrospective study enrolled 151 iCCA patients who received NAT. The percentage of residual viable tumor (%RVT) extent was calculated by RVT surface area/total tumor bed area ×100 and scored in 5% increments. Kaplan-Meier and Cox regression analyses were used to investigate its correlations with recurrence-free survival (RFS) and overall survival (OS). Tumor regression grading by the College of American Pathologists (CAP) and MD Anderson (MDA) methodologies were also validated. A 10% RVT-based tumor regression score (TRS) showed a significant correlation with both OS and RFS. TRS and major pathologic response (mPR) were therefore defined as follows: TRS 1/mPR, tumor with 0 to 10% RVT; TRS 2, more than 10% RVT. Patients graded as TRS 1/mPR had superior OS (P=0.006) and RFS (P<0.001) compared with those with TRS 2 in univariate analysis. In a multivariate analysis including ypTNM stages, lymphovascular invasion, and perineural invasion, TRS 1/mPR was also found to be an independent prognostic factor for both OS (hazard ratio [HR]: 0.226; 95% CI: 0.053-0.966, P=0.045) and RFS (HR: 0.474; 95% CI: 0.231-0.974, P=0.042). As for the CAP and MDA grading methodologies, they were found to correlate with RFS (CAP: P=0.002; MDA: P=0.001), but not with OS (CAP: P=0.181; MDA: P=0.09). Our study revealed that a TRS of ≤10% RVT significantly correlates with longer OS and RFS and can be suggested as an mPR in iCCA. This indicator is easily applicable, prognostically relevant, and could be further validated in future prospective clinical trials.

Association between volume of processed plasma and total bilirubin reduction during plasma adsorption for severe liver disease

BACKGROUND

The double plasma molecular adsorption system (DPMAS) is a crucial therapeutic modality for the management of severe liver disease. Current literature reports considerable variability in the volume of processed plasma (VPP) utilized during DPMAS treatment, and there is currently no consensus on the appropriate VPP. We aimed to investigate the relationship between VPP and changes in total bilirubin levels during DPMAS treatment.

METHODS

A prospective observational study with a repeated-measures design was conducted in patients with severe liver disease. The generalized estimation equations were used to evaluate the relationship between VPP and changes in total bilirubin levels during DPMAS treatment. The Bonferroni method was used for multiple comparisons. Tests for linear trends were performed by entering the median value of each category as a continuous variable. Total bilirubin level were detected repeatedly at four different times (four different VPP) (at 0.0 h (0 mL); at 2.0 h (3000 mL); at 2.5 h (3750 mL); at 3.0 h (4500 mL)).

RESULTS

Twenty-nine patients who underwent 75 sessions of DPMAS treatment were enrolled. The baseline total bilirubin levels and model for end-stage liver disease score were 426.1 (356.6-487.3) μmol/L and 21.9 (18.7-24.9). The total bilirubin levels and their reduction ratios in all patients (75 sessions) or patients with total bilirubin <425 μmol/L (39 sessions) or ≥425 μmol/L (36 sessions) decreased gradually and significantly at four different times (four different VPP) (all adjusted P for pairwise comparisons <0.001; adjusted P for trend <0.001). The reduction ratios of total bilirubin in patients with total bilirubin ≥425 μmol/L were similar to those with total bilirubin <425 μmol/L (adjusted OR (95% CI), 1.001 (0.966-1.036)). The positive relationship between the reduction ratios of total bilirubin and VPP was less remarkable in patients with higher height (adjusted P for interaction = 0.027) or lower albumin levels (adjusted P for interaction = 0.017).

CONCLUSION

The VPP of DPMAS treatment could be more than 4500 mL. Patients with higher height or lower albumin levels might require a higher VPP to achieve sufficient therapeutic efficacy.

High-sensitivity modified Glasgow prognostic score (HS-mGPS) is a prognostic biomarker for small duct-type intrahepatic cholangiocarcinoma-a retrospective cohort study

Background

Serum biomarkers are often used as part of preoperative prediction strategies to help assess a patient's surgical risk and prognosis. The high-sensitivity modified Glasgow prognostic score (HS-mGPS) has been shown to offer better predictive accuracy compared to the traditional Glasgow prognostic score (GPS) and the modified Glasgow prognostic score (mGPS) in various cancers, but its ability to predict outcomes in patients with resected intrahepatic cholangiocarcinoma (ICC) has not been well-studied. The aim of the study was to investigate the prognostic value of HS-mGPS in ICC and its subtypes.

Methods

This study was a single-center retrospective study. All patients who were pathologically diagnosed with ICC after surgery in Nanjing Drum Tower Hospital from 2012 and 2022. Relevant laboratory data such as serum C-reactive protein (CRP), albumin (ALB), neutrophils, lymphocytes, and platelets were included. Overall survival (OS) information was collected, serum CRP and ALB level were used for scoring GPS, mGPS and HS-mGPS. Univariate and multivariate analyses were conducted to identify factors influencing prognosis by using Kaplan-Meier (KM) curve and Cox proportional hazards models. Additionally, through histological analysis, ICC was classified into large duct type (LD-type) and small duct type (SD-type), and the performance of the three scoring systems in these subtypes was examined.

Results

A total of 185 patients were included in this study, 57 cases were of the LD-type, and 128 cases were of the SD-type. Tumor subtypes was a significant factor influencing prognosis for all ICC patients [hazard ratio (HR) =1.76, 95% confidence interval (CI): 1.036-2.994, P=0.04]. HS-mGPS demonstrated a better ability to predict outcomes compared to GPS and mGPS, and was an independent prognostic factor of OS (HR =2.1, 95% CI: 1.001-4.374, P=0.049). HS-mGPS was also more effective in predicting prognosis for SD-type ICC compared to GPS and mGPS (HR =3.13, 95% CI: 1.018-9.604, P=0.046), while it was ineffective for LD-type ICC. Further analysis revealed that SD-type ICC with higher HS-mGPS scores typically had larger tumors and poorer differentiation, while LD-type ICC showed no significant differences.

Conclusions

HS-mGPS provides a more accurate prognostic indication for SD-type, but its effectiveness for LD-type requires further investigation with larger sample sizes. Therefore, for preoperatively biopsy-diagnosed SD-type ICC, the HS-mGPS has a certain level of prognostic predictive potential.

Primary hepatocellular carcinosarcoma: A case series and literature review

INTRODUCTION

Hepatocellular carcinosarcoma (HCS) is a rare and aggressive liver tumor with limited clinical evidence due to its infrequency. This case series aimed to enrich the existing knowledge on the diagnosis and clinical management of HCS.

METHODS

Four patients with HCS were evaluated, focusing on their symptoms, diagnoses, treatments, and outcomes. The imaging characteristics and tumorigenesis of HCS were also investigated, highlighting the role of p53 mutations.

RESULTS

This case series found that timely surgery and localized chemotherapy are crucial in managing HCS. Despite the promising results of targeted therapy, its limitations were observed in some patients. The onset and progression of HCS were found to be significantly correlated with the presence of p53 mutations.

CONCLUSIONS

This case series underscores the need for further research to improve the diagnosis and treatment of HCS and emphasizes the importance of timely surgery and localized chemotherapy in mitigating tumor side effects and potentially prolonging survival.

LARP3 inhibits the apoptosis of hepatocellular carcinoma via the ROS/PI3K/c-Fos axis

Primary hepatocellular carcinoma (PHC) is the sixth most common cancer and the third leading cause of cancer death worldwide. Hepatocellular carcinoma (HCC) accounts for 75%-85% of PHC. LARP3 is aberrantly expressed in multiple cancers. We found that it is significantly highly expressed in the liver cancer tissues of HCC patients, but the exact role and specific mechanism of this abnormal expression are not yet clear. In this study, through bioinformatics analysis, we concluded that LARP3 expression is associated with a poor prognosis for patients with HCC. Through cellular experiments such as gene editing and phenotypic functions, we found that LARP3 promotes the occurrence and development of HCC and inhibits apoptosis. Finally, through biological means such as RNA sequencing, flow cytometry, western blotting, and the construction of a subcutaneous tumorigenesis model in nude mice, we concluded that inhibition of HCC apoptosis by LARP3 is related to LARP3 negatively regulating ROS level and inhibiting the PI3K/c-Fos/apoptosis axis. This study will provide potential targets for the treatment of HCC.

Free Cholesterol-Induced Liver Injury in Non-Alcoholic Fatty Liver Disease: Mechanisms and a Therapeutic Intervention Using Dihydrotanshinone I

Build-up of free cholesterol (FC) substantially contributes to the development and severity of non-alcoholic fatty liver disease (NAFLD). Here, we investigate the specific mechanism by which FC induces liver injury in NAFLD and propose a novel therapeutic approach using dihydrotanshinone I (DhT). Rather than cholesterol ester (CE), we observed elevated levels of total cholesterol, FC, and alanine transaminase (ALT) in NAFLD patients and high-cholesterol diet-induced NAFLD mice compared to those in healthy controls. The FC level demonstrated a positive correlation with the ALT level in both patients and mice. Mechanistic studies revealed that FC elevated reactive oxygen species level, impaired the function of lysosomes, and disrupted lipophagy process, consequently inducing cell apoptosis. We then found that DhT protected mice on an HCD diet, independent of gut microbiota. DhT functioned as a potent ligand for peroxisome proliferator-activated receptor α (PPARα), stimulating its transcriptional function and enhancing catalase expression to lower reactive oxygen species (ROS) level. Notably, the protective effect of DhT was nullified in mice with hepatic PPARα knockdown. Thus, these findings are the first to report the detrimental role of FC in NAFLD, which could lead to the development of new treatment strategies for NAFLD by leveraging the therapeutic potential of DhT and PPARα pathway.

The Chromosome Passenger Complex (CPC) Components and Its Associated Pathways Are Promising Candidates to Differentiate Between Normosensitive and Radiosensitive ATM-Mutated Cells

Background

Sensitivity to ionizing radiation differs between individuals, but there is a limited understanding of the biological mechanisms that account for these variations. One example of such mechanisms are the mutations in the ATM (mutated ataxia telangiectasia) gene, that cause the rare recessively inherited disease Ataxia telangiectasia (AT). Hallmark features include chromosomal instability and increased sensitivity to ionizing radiation (IR).

Objectives

To deepen the molecular understanding of radiosensitivity and to identify potential new markers to predict it, human ATM-mutated and proficient cells were compared on a proteomic level.

Design

In this study, we analyzed 3 cell lines from AT patients, with varying radiosensitivity, and 2 cell lines from healthy volunteers, 24 hours and 72 hours post-10 Gy irradiation.

Methods

We used label-free mass spectrometry to identify differences in signaling pathways after irradiation in normal and radiosensitive individuals. Cell viability was initially determined by water soluble tetrazolium (WST) assay and DNA damage response was analyzed with 53BP1 repair foci formation along with KRAB-associated protein 1 (KAP1) phosphorylation.

Results

Proteomic analysis identified 4028 proteins, which were used in subsequent in silico pathway enrichment analysis to predict affected biological pathways post-IR. In AT cells, networks were heterogeneous at both time points with no common pathway identified. Mitotic cell cycle progress was the most prominent pathway altered after IR in cells from healthy donors. In particular, components of the chromosome passenger complex (INCENP and CDCA8) were significantly downregulated after 72 hours. This could also be verified at the mRNA level.

Conclusion

Altogether, the most striking result was that proteins forming the chromosome passenger complex were downregulated after radiation exposure in healthy normosensitive control cells, but not in radiosensitive ATM-deficient cells. Thus, mitosis-associated proteins form an interesting compound to gain insights into the development and prediction of radiosensitivity.

Clinicopathological features of cholangiolocarcinoma and impact of tumor heterogeneity on prognosis: A single institution retrospective study

Cholangiolocarcinoma (CLC) is an extremely rare tumor classified as a subtype of small duct-type intrahepatic cholangiocarcinoma (iCCA). There are few detailed reports on CLC and the prognostic impact of tumor heterogeneity is not clear. Between April 2006 and June 2022, of the 774 primary liver cancer resection cases who presented at Kanazawa University Hospital, 14 patients were pathologically diagnosed with CLC through immunohistochemical analysis of their molecular and biological features. Clinicopathological features and prognoses were evaluated retrospectively. Additionally, tumor heterogeneity was assessed and tumors were classified into pure and partial types according to the CLC component proportion in a single tumor. Chronic liver disease was observed in nine patients (64.3%). All tumors were mass-forming, and pathological R0 resection was achieved in 11 patients (78.6%). Tumor heterogeneity was classified as pure in 11 (78.6%) and partial in three (21.4%) patients. The median follow-up was 59.5 months (12-114 months). There was no difference in the 5-year disease-specific survival rates between the pure and partial (90.0% vs. 100.0%; P=0.200) types, but rates were significantly higher in the R0 resection group compared with those in the R1 resection group (100.0% vs. 50.0%; P=0.025). In conclusion, these results suggest that it is important for CLC patients to achieve curative resection, and CLC may have a good prognosis regardless of the proportion of CLC components in a single tumor.

Recent Advances in Pathology of Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICCA) is a malignant epithelial neoplasm characterized by biliary differentiation within the liver. ICCA is molecularly heterogeneous and exhibits a broad spectrum of histopathological features. It is a highly aggressive carcinoma with high mortality and poor survival rates. ICCAs are classified into two main subtypes: the small-duct type and large-duct types. These two tumor types have different cell origins and clinicopathological features. ICCAs are characterized by numerous molecular alterations, including mutations in KRAS, TP53, IDH1/2, ARID1A, BAP1, BRAF, SAMD4, and EGFR, and FGFR2 fusion. Two main molecular subtypes-inflammation and proliferation-have been proposed. Recent advances in high-throughput assays using next-generation sequencing have improved our understanding of ICCA pathogenesis and molecular genetics. The diagnosis of ICCA poses a significant challenge for pathologists because of its varied morphologies and phenotypes. Accurate diagnosis of ICCA is essential for effective patient management and prognostic determination. This article provides an updated overview of ICCA pathology, focusing particularly on molecular features, histological subtypes, and diagnostic approaches.