Background Mitochondrial dynamics plays an important role in tumour progression. However, how these dynamics integrate tumour metabolism in hepatocellular carcinoma (HCC) metastasis is still unclear. Methods The mitochondrial fusion protein mitofusin-1 (MFN1) expression and its prognostic value are detected in HCC. The effects and underlying mechanisms of MFN1 on HCC metastasis and metabolic reprogramming are analysed both in vitro and in vivo. Results Mitochondrial dynamics, represented by constant fission and fusion, are found to be associated with HCC metastasis. High metastatic HCC displays excessive mitochondrial fission. Among genes involved in mitochondrial dynamics, MFN1 is identified as a leading downregulated candidate that is closely associated with HCC metastasis and poor prognosis. While promoting mitochondrial fusion, MFN1 inhibits cell proliferation, invasion and migration capacity both in vitro and in vivo. Mechanistically, disruption of mitochondrial dynamics by depletion of MFN1 triggers the epithelial-to-mesenchymal transition (EMT) of HCC. Moreover, MFN1 modulates HCC metastasis by metabolic shift from aerobic glycolysis to oxidative phosphorylation. Treatment with glycolytic inhibitor 2-Deoxy-d-glucose (2-DG) significantly suppresses the effects induced by depletion of MFN1. Conclusions Our results reveal a critical involvement of mitochondrial dynamics in HCC metastasis via modulating glucose metabolic reprogramming. MFN1 may serve as a novel potential therapeutic target for HCC.

Background and Aims: Pyruvate kinase M2 (PKM2) is an essential regulator of the Warburg effect, but its biological function promoting immune escape of hepatocellular carcinoma (HCC) is unclear.Methods: GEPIA web tool and immunohistochemistry (IHC) analysis were employed to evaluate the clinical relevance of PKM2 in HCC patients. Both in vitro CCK-8, colony formation, and transwell assays, and in vivo xenografts were performed to evaluate the malignancy of HCC cells. PKM2 and PD-L1 levels were examined by Western blot, qRT-PCR, and IHC. The role of PKM2 on in vivo immune response was also investigated.Results: PKM2 was significantly upregulated in HCC and associated with a poor prognosis of HCC patients. Knockdown of PKM2 inhibited in vitro proliferation, migration, and invasion of HCC cells, as well as in vivo tumor growth. Strikingly, PKM2 showed a strong correlation with the expression of immune inhibitory cytokines and lymphocyte infiltration in HCC. The overexpression of PKM2 sensitized HCC to immune checkpoint blockade, which enhanced IFN-g positive CD8 T cells in HCC mice models. Conclusion:PKM2 might be a predictor and a potential therapeutic target for immune checkpoint inhibitors in HCC.

Lenvatinib is an inhibitor of multiple receptor tyrosine kinases that was recently authorized for first-line treatment of hepatocellular carcinoma (HCC). However, the clinical benefits derived from lenvatinib are limited, highlighting the urgent need to understand mechanisms of resistance. We report here that HCC cells develop resistance to lenvatinib by activating epidermal growth factor receptor (EGFR) and stimulating the EGFR-STAT3-ABCB1 axis. Lenvatinib resistance was accompanied by aberrant cholesterol metabolism and lipid raft activation. ABCB1 was activated by EGFR in a lipid raft-dependent manner, which significantly enhanced the exocytosis of lenvatinib to mediate resistance. Furthermore, clinical specimens of HCC showed a correlation between the activation of the EGFR-STAT3-ABCB1 pathway and lenvatinib response. Erlotinib, an EGFR inhibitor that has also been shown to inhibit ABCB1, suppressed lenvatinib exocytosis, and combined treatment with lenvatinib and erlotinib demonstrated a significant synergistic effect on HCC both in vitro and in vivo. Taken together, these findings characterize a mechanism of resistance to a first-line treatment for HCC and offer a practical means to circumvent resistance and treat the disease.

Background: Growing evidence suggests that the bidirectional interactions between cancer cells and their surrounding environment namely the tumor microenvironment (TME), contributes to cancer progression, metastasis, and resistance to treatment. Intense investigation of Hippo pathway, which controls multiple central cellular function to tumorigenesis, was focused on cancer cells. However, the role of Hippo pathway in modulating tumor-stromal interactions in triple negative breast cancer remains largely unknow. This study therefore focused on revealing effects of Hippo-YAP/TAZ signaling to immune microenvironment.Methods: The correlation between Hippo/YAP signaling and the abundance of immune cells were estimated by Immune Cell Abundance Identi er. Clinical TNBC samples from 120 patients were analyzed to assess the correlation between TAZ expression and disease prognosis as well as tumor-in ltrating immune cells. In ammatory immune pro les, bioinformatics analysis and chromatin immunoprecipitation were performed to identify the expression of immune-related genes that were regulated by TAZ. An in vitro co-culture system was applied to investigate the crosstalk between TNBC cells and tumor-associated macrophages (TAMs) modulated by the TAZ/interleukin 34 (IL-34) axis. In vivo tumor growth and metastasis models were used to evaluate the pro-tumor functions of TAZ, IL-34, and TAMs as well as the antitumor e cacy of anti-PD-L1 and IL-34/colony-stimulating factor 1 receptor (CSF-1R) blockade.Results: In TNBC patients, high activity of Hippo pathway was correlated with decreased number of T cells, upregulated TAM in ltration, and poor prognosis. TAZ could directly regulate IL-34 and PD-L1 expression and promote IL-34 secretion in TNBC cells, leading to increased TAM in ltration and distant metastasis. TAM-derived transforming growth factor beta 1 (TGF-β1) could also induce TAZ expression in TNBC cells, thus forming a positive feedback loop between TNBC cells and TAMs. Furthermore, targeting the TAZ/IL-34 axis through its CSF-1R inhibitor could dramatically decrease TAM in ltration and signi cantly improve anti-PD-L1 e cacy in inhibiting metastasis in TNBC.Conclusions: Activity of Hippo pathway was associated with worse disease outcomes in TNBC and could increase TAM in ltration through the TAZ/IL-34 axis, leading to an immunosuppressive microenvironment and impairing the treatment e cacy of anti-PD-L1. Thus, the TAZ/IL-34 axis can serve as a novel target for TNBC patients.

Purpose: To establish a clinically applicable genomic clustering system, we investigated the interactive landscape of driver mutations in intrahepatic cholangiocarcinoma (ICC). Methods: The genomic data of 1481 ICCs from diverse populations was analyzed to investigate the pair-wise co-occurrences or mutual exclusivities among recurrent driver mutations. Clinicopathological features and outcomes were compared among different clusters. Gene expression and DNA methylation profiling datasets were analyzed to investigate the molecular distinctions among mutational clusters. ICC cell lines with different gene mutation backgrounds were used to evaluate the cluster specific biological behaviors and drug sensitivities. Results: Statistically significant mutation-pairs were identified across 21 combinations of genes. Seven most recurrent driver mutations ( TP53 , KRAS , SMAD4 , IDH1 /2, FGFR2-fus and BAP1 ) showed pair-wise co-occurrences or mutual exclusivities and could aggregate into three genetic clusters: Cluster1: represented by tripartite interaction of KRAS , TP53 and SMAD4 mutations, exhibited large bile duct histological phenotype with high CA19-9 level and dismal prognosis; Cluster2: co-association of IDH / BAP1 or FGFR2-fus / BAP1 mutation, was characterized by small bile duct phenotype, low CA19-9 level and optimal prognosis; Cluster3: mutation-free ICC cases with intermediate clinicopathological features. These clusters showed distinct molecular traits, biological behaviors and responses to therapeutic drugs. Finally, we identified S100P and KRT17 as “cluster-specific”, “lineage-dictating” and “prognosis-related” biomarkers, which in combination with CA19-9 could well stratify Cluster3 ICCs into two biologically and clinically distinct subtypes. Conclusions: This clinically applicable clustering system can be instructive to ICC prognostic stratification, molecular classification, and therapeutic optimization.

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Background: The hepatitis B virus (HBV)-related intrahepatic cholangiocarcinoma (iCCA) was recognized as a unique subtype of iCCA, within particular features in demography, clinicopathology, and genealogy. However, how they predict prognosis, in particular, for HBV-and non-HBV-related iCCA is still unclear. Methods: Demographic, clinicopathologic, and genetic features were retrospectively collected and reviewed to determine the specific prognostic factors, precisely predicting the overall survival (OS) in HBV-related (n = 119) and non-HBV-related (n = 149) iCCA patients, respectively. Results: In HBV-related iCCA, TP53 mutation, vascular invasion, extrahepatic metastasis, and serum levels of alpha-fetoprotein (AFP) were independent prognostic factors for OS. In non-HBV-related iCCA, RAS/RAF mutation and lymphatic metastasis independently predicted the OS of patients. Tumor differentiation and serum levels of CA19-9 were significantly associated with OS in both HBV-and non-HBV-related iCCA patients. In a subset analysis, TP53 and RAS/RAF mutations were consistently related to poorer outcome in HBVand non-HBV-related iCCA, respectively. Conclusions: The HBV-and non-HBV-related iCCA have different prognostic factors for the OS.K E Y W O R D S hepatitis B virus, intrahepatic cholangiocarcinoma, overall survival, RAS/RAF, TP53 1 | INTRODUCTION Intrahepatic cholangiocarcinoma (iCCA) is the second most common liver malignancy and usually refractory to standard treatment, resulting in a high frequency of recurrence and mortality. 1 Among all the etiological factors of iCCA, hepatitis B virus (HBV) infection is attracting more attention 2,3 as HBV-related iCCA has been proved possessing distinct demographic and clinicopathologic features. Patients are more likely to be male and younger, have less lymphatic metastasis, higher serum levels of alpha-fetoprotein (AFP), and better outcomes. 4,5Moreover, compared with non-HBV-related iCCA, HBV-related iCCA is more likely to have cholangiolar differentiation, present with a mass-forming subtype, and express low N-cadherin. 6,7 There is a concern that HBV-related iCCA might be recognized as a unique subtype of iCCA, and requires a more specific treatment.

Background and Aims : The tumor microenvironment can be divided into inflamed, immune-excluded and immune - desert phenotypes according to CD8 + T cell categories with differential programmed cell death protein 1 (PD-L1) expression. The study aims to construct a novel immunotype-based risk stratification model to predict postsurgical survival and adjuvant trans-arterial chemoembolization (TACE) response in patients with hepatocellular carcinoma (HCC). Methods: A total of 220 eligible HCC patients participated in this study. CD8 + T cell infiltration and PD-L1 expression mode were estimated by immunohistochemical staining. A risk stratification model was developed and virtualized by a nomogram that integrated these independent prognostic factors. The postoperative prognosis and adjuvant TACE benefits were evaluated with a novel immunotype-based risk stratification model. Results: A total of 220 patients were finally identified. Immune-desert, immune-excluded, and inflamed immunotypes represented 45%, 24%, and 31% of HCC, respectively. Univariate and multivariate analyses identified immunotype and PD-L1 expression mode as independent prognostic factors for overall survival time (OS) and recurrence-free survival time (RFS). The nomogram was constructed by integrating immunotype, PD-L1 expression, Barcelona Clinic Liver Cancer (BCLC) stage and tumor grade. The C-index was 0.794 in the training cohort and 0.813 in the validation cohort. A risk stratification system was constructed based on the nomogram classifying HCC patients into 3 risk groups. The average OS times in the low-risk, intermediate-risk and high-risk groups in all cohorts were 77.1 months (95% CI 71.4-82.9), 53.7 months (95% CI 48.2-59.2), and 25.6 months (95% CI 21.4-29.7), respectively. Further analysis showed that OS was significantly improved by adjuvant TACE in the low- and intermediate-risk groups ( P= 0.041 and P =0.010, respectively) but not in the high-risk group ( P =0.398). Conclusion: A novel immunotype-based risk stratification model was built to predict postoperative prognosis and adjuvant TACE benefit in HCC patients. These tools can assist in building a more customized method of HCC treatment.