Cholesterol suppresses AMFR-mediated PDL1 ubiquitination and degradation in HCC.

The degradation of proteasomes or lysosomes is emerging as a principal determinant of programmed death ligand 1 (PDL1) expression, which affects the efficacy of immunotherapy in various malignancies. Intracellular cholesterol plays a central role in maintaining the expression of membrane receptors; however, the specific effect of cholesterol on PDL1 expression in cancer cells remains poorly understood. Cholesterol starvation and stimulation were used to modulate the cellular cholesterol levels. Immunohistochemistry and western blotting were used to analyze the protein levels in the samples and cells. Quantitative real-time PCR, co-immunoprecipitation, and confocal co-localization assays were used for mechanistic investigation. A xenograft tumor model was constructed to verify these results in vivo. Our results showed that cholesterol suppressed the ubiquitination and degradation of PDL1 in hepatocellular carcinoma (HCC) cells. Further mechanistic studies revealed that the autocrine motility factor receptor (AMFR) is an E3 ligase that mediated the ubiquitination and degradation of PDL1, which was regulated by the cholesterol/p38 mitogenic activated protein kinase axis. Moreover, lowering cholesterol levels using statins improved the efficacy of programmed death 1 (PD1) inhibition in vivo. Our findings indicate that cholesterol serves as a signal to inhibit AMFR-mediated ubiquitination and degradation of PDL1 and suggest that lowering cholesterol by statins may be a promising combination strategy to improve the efficiency of PD1 inhibition in HCC.

Ex vivo liver resection and auto-transplantation as an alternative for the treatment of liver malignancies: Progress and challenges.

Hepatectomy is still the major curative treatment for patients with liver malignancies. However, it is still a big challenge to remove the tumors in the central posterior area, especially if their location involves the retrohepatic inferior vena cava and hepatic veins. Ex vivo liver resection and auto-transplantation (ELRA), a hybrid technique of the traditional liver resection and transplantation, has brought new hope to these patients and therefore becomes a valid alternative to liver transplantation. Due to its technical difficulty, ELRA is still concentrated in a few hepatobiliary centers that have experienced surgeons in both liver resection and liver transplantation. The efficacy and safety of this technique has already been demonstrated in the treatment of benign liver diseases, especially in the advanced alveolar echinococcosis. Recently, the application of ELRA for liver malignances has gained more attention. However, standardization of clinical practice norms and international consensus are still lacking. The prognostic impact in these oncologic patients also needs further evaluation. In this review, we summarized the principles and recent progresses on ELRA.

Early Circulating Tumor DNA Dynamics Predict Neoadjuvant Therapy Response and Recurrence in Colorectal Liver Metastases: A Prospective Study.

BACKGROUND: For patients with colorectal liver metastases (CRLM) who receive neoadjuvant therapy (NAT), reliable indicators that can early and accurately predict treatment response are lacking. This study was conducted to prospectively investigate the potential of early circulating tumor DNA (ctDNA) dynamics as a precise predictor of NAT response and recurrence in CRLM. METHODS: This study prospectively enrolled 34 patients with CRLM who received NAT, with blood samples collected and subjected to deep targeted panel sequencing at two time points: 1 day before the first and the second cycles of NAT. Correlations of ctDNA mean variant allele frequency (mVAF) dynamics and treatment response were assessed. The performance of early ctDNA dynamics in predicting treatment response was assessed and compared with those of carcinoembryonic antigen (CEA) and cancer antigen 19-9 (CA19-9). RESULTS: The baseline ctDNA mVAF was significantly associated with pre-NAT tumor diameter (r = 0.65; P < 0.0001). After one cycle of NAT, the ctDNA mVAF declined remarkably (P < 0.0001). The dynamic change in ctDNA mVAF of 50% or more was significantly correlated with better NAT responses. The discriminatory capacity of ctDNA mVAF changes was superior to that of CEA or CA19-9 in predicting radiologic response (area under the curve [AUC], 0.90 vs 0.71 vs 0.61) and pathologic tumor regression grade (AUC, 0.83 vs 0.64 vs 0.67). The early changes in ctDNA mVAF but not CEA or CA19-9 were an independent indicator of recurrence-free survival (RFS) (hazard ratio, 4.0; P = 0.023). CONCLUSIONS: For CRLM patients receiving NAT, an early ctDNA change is a superior predictor of treatment response and recurrence compared with conventional tumor markers.

S100 calcium-binding protein A9 from tumor-associated macrophage enhances cancer stem cell-like properties of hepatocellular carcinoma.

Tumor-associated macrophages (TAMs) are crucial components of the tumor microenvironment. They play vital roles in hepatocellular carcinoma (HCC) progression. However, the interactions between TAMs and HCC cells have not been fully characterized. In this study, TAMs were induced using human monocytic cell line THP-1 cells in vitro to investigate their functions in HCC progression. S100 calcium-binding protein A9 (S100A9), an inflammatory microenvironment-related secreted protein, was identified to be significantly upregulated in TAMs. S100A9 expression in tumor tissues was associated with poor survival of HCC patients. It could enhance the stem cell-like properties of HepG2 and MHCC-97H cells by activating nuclear factor-kappa B signaling pathway through advanced glycosylation end product-specific receptor in a Ca2+ -dependent manner. Furthermore, we found that, after treatment with S100A9, HepG2 and MHCC-97H cells recruited more macrophages via chemokine (CC motif) ligand 2, which suggests a positive feedback between TAMs and HCC cells. Taken together, our findings reveal that TAMs could upregulate secreted protein S100A9 and enhance the stem cell-like properties of HCC cells and provide a potential therapeutic target for combating HCC.

Left Hepatic Vein Preferential Approach Based on Anatomy Is Safe and Feasible for Laparoscopic Living Donor Left Lateral Sectionectomy.

We assess the safety and feasibility of the left hepatic vein preferential approach (LHVPA) based on left hepatic vein (LHV) anatomy for living donor laparoscopic left lateral sectionectomy (LLLS). Data from 50 donors who underwent LLLS in Huashan Hospital from October 2016 to November 2019 were analyzed retrospectively. On the basis of the classification of the LHV anatomy, the vein was defined as the direct import type, upper branch type, or indirect import type. A subgroup analysis was performed to compare the outcomes between the LHVPA and non-LHVPA groups. All 50 patients underwent pure LLLS. The mean operative duration was 157.5 ± 29.7 minutes. The intraoperative blood loss was 160.4 ± 97.5 mL. No complications more severe than grade 3 occurred. LHVPA was applied in 13 patients, whereas non-LHVPA was applied in 10 patients with the direct import type and upper branch type anatomy. The operative duration was shorter in the LHVPA group than the non-LHVPA group (142.7 ± 22.0 versus 173.0 ± 22.8 minutes; P = 0.01). Intraoperative blood loss was reduced in the LHVPA group compared with the non-LHVPA group (116.2 ± 45.6 versus 170.0 ± 63.3 mL; P = 0.02). The length of the LHV reserved extrahepatically in the LHVPA group was longer than in the non-LHVPA group (4.3 ± 0.2 versus 3.3 ± 0.3 mm; P = 0.01). Fewer reconstructions of the LHV in the direct import type anatomy were required for the LHVPA group than for the non-LHVPA group (0/8 versus 4/6). LHVPA based on the LHV anatomy is recommended in LLLS because it can further increase the safety and the efficiency of surgery for suitable donors.

RA190, a Proteasome Subunit ADRM1 Inhibitor, Suppresses Intrahepatic Cholangiocarcinoma by Inducing NF-KB-Mediated Cell Apoptosis.

BACKGROUND/AIMS: Effective drug treatment for intrahepatic cholangiocarcinoma (ICC) is currently lacking. Therefore, there is an urgent need for new targets and new drugs that can prolong patient survival. Recently targeting the ubiquitin proteasome pathway has become an attractive anti-cancer strategy. In this study, we aimed to evaluate the therapeutic effect of and identify the potential mechanisms involved in targeting the proteasome subunit ADRM1 for ICC. METHODS: The expression of ADRM1 and its prognostic value in ICC was analyzed using GEO and TCGA datasets, tumor tissues, and tumor tissue arrays. The effects of RA190 on the proliferation and survival of both established ICC cell lines and primary ICC cells were examined in vitro. Annexin V/propidium iodide staining, western blotting and immunohistochemical staining were performed. The in vivo anti-tumor effect of RA190 on ICC was validated in subcutaneous xenograft and patient-derived xenograft (PDX) models. RESULTS: ADRM1 levels were significantly higher in ICC tissues than in normal bile duct tissues. ICC patients with high ADRM1 levels had worse overall survival (hazard ratio [HR] = 2.383, 95% confidence interval [CI] =1.357 to 4.188) and recurrence-free survival (HR = 1.710, 95% CI =1.045 to 2.796). ADRM1 knockdown significantly inhibited ICC growth in vitro and in vivo. The specific inhibitor RA190 targeting ADRM1 suppressed proliferation and reduced cell vitality of ICC cell lines and primary ICC cells significantly in vitro. Furthermore, RA190 significantly inhibited the proteasome by inactivating ADRM1, and the consequent accumulation of ADRM1 substrates decreased the activating levels of NF-κB to aggravate cell apoptosis. The therapeutic benefits of RA190 treatment were further demonstrated in both subcutaneous implantation and PDX models. CONCLUSIONS: Our findings indicate that up-regulated ADRM1 was involved in ICC progression and suggest the potential clinical application of ADRM1 inhibitors (e.g., RA190 and KDT-11) for ICC treatment.

Tissue-specific significance of BAP1 gene mutation in prognostic prediction and molecular taxonomy among different types of cancer.

BAP1 is an emerging tumor suppressor whose inactivating mutations have been found to play critical roles in tumor development. This study was conducted to elucidate the potential value of BAP1 mutation in guiding prognostic prediction and clinical stratification. We conducted a comprehensive analysis of relevant studies from multiple databases, to determine the impact of BAP1 mutation on the overall survival and disease-free survival of patients in various cancers. A total of 2457 patients from 21 studies were included in the final analysis. Although the pooled results demonstrated that BAP1 mutation was a negative indicator of overall survival (hazard ratio = 1.73; 95% confidence interval = 1.23-2.42) and disease-free survival (hazard ratio = 2.25; 95% confidence interval = 1.47-3.45), this prognostic value was only applicable to uveal melanoma and clear cell renal cell carcinoma, but not to malignant pleural mesothelioma or cholangiocarcinoma. Consistently, BAP1 mutation was correlated with critical clinicopathological features only in uveal melanoma and clear cell renal cell carcinoma. In uveal melanoma, BAP1 mutation and SF3B1/EIF1AX mutations were negatively correlated, and BAP1-mutant tumors indicated significant worse prognosis than SF3B1/EIF1AX-mutant tumors ( p = 0.028). While in clear cell renal cell carcinoma, BAP1 mutation was mutually exclusive with PBRM1 mutations, and BAP1-mutant clear cell renal cell carcinomas also showed significantly worse prognosis than PBRM1-mutant clear cell renal cell carcinomas ( p = 0.001). Our study revealed a unique tissue-specific significance of BAP1 mutation in prognostic prediction among different types of cancer. Clinically, combining detection of BAP1 mutation and other driver mutations may further allow for a more precise molecular taxonomy to stratify patients into distinct subgroups in uveal melanoma and clear cell renal cell carcinoma.

Association between XPG polymorphisms and stomach cancer susceptibility in a Chinese population.

Xeroderma pigmentosum group G (XPG) protein plays an important role in the DNA repair process by cutting the damaged DNA at the 3' terminus. Previous studies have indicated some polymorphisms in the XPG gene are associated with stomach cancer susceptibility. We performed this hospital-based case-control study to evaluate the association of four potentially functional XPG polymorphisms (rs2094258 C>T, rs751402 C>T, rs2296147 T>C and rs873601G>A) with stomach cancer susceptibility. The four single nucleotide polymorphisms (SNPs) were genotyped in 692 stomach cancer cases and 771 healthy controls. Logistic regression analysis was conducted, and odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the association of interest. Of the studied SNPs, XPG rs873601G>A polymorphism was found to significantly associate with stomach cancer susceptibility (AA versus GG/AG: OR = 1.31, 95% CI = 1.03-1.66, P = 0.027). Combined analysis of all SNPs revealed that the individuals with two of risk genotypes had a significantly increased stomach cancer risk (OR = 1.52, 95% CI = 1.13-2.06). In the stratification analysis, the association between the rs873601AA genotype and stomach cancer risk was observed in older group (>59 year), as well as patients with non-cardia stomach cancer. Further combined analysis indicated men, smokers, or non-drinkers more than one risk genotypes had a significantly increased stomach cancer risk. Our results indicate that XPG rs873601G>A polymorphism may be associated with the risk of stomach cancer. Further prospective studies with different ethnicities and large sample sizes are needed to validate our findings.

The application of real-time indocyanine green fluorescence cholangiography in laparoscopic living donor left lateral sectionectomy.

Background: The judgment of the division point of the bile duct has always been one of the difficulties of laparoscopic left lateral sectionectomy (LLLS). The purpose of this study was to assess the effects of indocyanine green (ICG) fluorescence cholangiography during LLLS on the occurrence of biliary complications in both donors and recipients. The optimal dose and injection time of ICG were also investigated. Methods: This is a retrospective cohort study. From October 2016 to December 2022, the clinical data of 103 donors who underwent LLLS and relevant recipients were retrospectively analyzed. According to whether ICG fluorescence cholangiography was used, they were divided into a non-ICG group (n=46) and an ICG group (n=57). Biliary complications were observed and the optimal dose and injection time of ICG were explored. Results: Three donors in the non-ICG group suffered from bile leakage. Four grafts had multiple bile duct openings and biliary complications were observed in the relevant recipients who received these grafts in the non-ICG group. Two recipients had bile leakage, and the other two had biliary stenosis. There was no biliary complications both in donors and recipients in the ICG group. The fluorescence intensity of the liver was 108.1±17.6 at a dose of 0.004 mg/kg 90 minutes after injection, significantly weaker than that at 0.05 mg/kg 30 minutes (200.3±17.6, P=0.001) and 90 minutes after injection (140.2±15.4, P=0.001). The fluorescence intensity contrast value at a dose of 0.004 mg/kg was stronger than that at 0.05 mg/kg, both measured 90 minutes after injection (0.098±0.032 vs. 0.078±0.022, P=0.021). Conclusions: ICG fluorescence cholangiography is safe and feasible in LLLS. It reduces biliary complications in both donors and recipients. The optimal ICG dose was 0.004 mg/kg, and 90 minutes after injection was the best observation time. ICG fluorescence cholangiography is recommended for routine use in LLLS.

Acetyl-CoA metabolic accumulation promotes hepatocellular carcinoma metastasis via enhancing CXCL1-dependent infiltration of tumor-associated neutrophils.

High levels of acetyl-CoA are considered a key metabolic feature of metastatic cancers. However, the impacts of acetyl-CoA metabolic accumulation on cancer microenvironment remodeling are poorly understood. In this study, using human hepatocellular carcinoma (HCC) tissues and orthotopic xenograft models, we found a close association between high acetyl-CoA levels in HCCs, increased infiltration of tumor-associated neutrophils (TANs) in the cancer microenvironment and HCC metastasis. Cytokine microarray and enzyme-linked immunosorbent assays (ELISA) revealed the crucial role of the chemokine (C-X-C motif) ligand 1(CXCL1). Mechanistically, acetyl-CoA accumulation induces H3 acetylation-dependent upregulation of CXCL1 gene expression. CXCL1 recruits TANs, leads to neutrophil extracellular traps (NETs) formation and promotes HCC metastasis. Collectively, our work linked the accumulation of acetyl-CoA in HCC cells and TANs infiltration, and revealed that the CXCL1-CXC receptor 2 (CXCR2)-TANs-NETs axis is a potential target for HCCs with high acetyl-CoA levels.

Cirrhotic-extracellular matrix attenuates aPD-1 treatment response by initiating immunosuppressive neutrophil extracellular traps formation in hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is closely associatedwith chronic liver diseases, particularly liver cirrhosis, which has an altered extracellular matrix (ECM) composition. The influence and its mechanism of the cirrhotic-ECM on the response of HCC to immune checkpoint inhibitor (ICI) remains less clarified. METHODS: In silico, proteomic and pathological assessment of alteration of cirrhotic-ECM were applied in clinical cohort. Multiple pre-clinical models with ECM manipulation were used to evaluate cirrhotic-ECM's effect on ICI treatment. In silico, flow cytometry and IHC were applied to explore how cirrhotic-ECM affect HCC microenvironment. In vitro and in vivo experiments were carried out to identify the mechanism of how cirrhotic-ECM undermined ICI treatment. RESULTS: We defined "a pro-tumor cirrhotic-ECM" which was featured as the up-regulation of collagen type 1 (Col1). Cirrhotic-ECM/Col1 was closely related to impaired T cell function and limited anti PD-1 (aPD-1) response of HCC patients from the TCGA pan cancer cohort and the authors' institution, as well as in multiple pre-clinical models. Mechanically, cirrhotic-ECM/Col1 orchestrated an immunosuppressive microenvironment (TME) by triggering Col1-DDR1-NFκB-CXCL8 axis, which initiated neutrophil extracellular traps (NETs) formation to shield HCC cells from attacking T cells and impede approaching T cells. Nilotinib, an inhibitor of DDR1, reversed the neutrophils/NETs dominant TME and efficiently enhanced the response of HCC to aPD-1. CONCLUSIONS: Cirrhotic-ECM modulated a NETs enriched TME in HCC, produced an immune suppressive TME and weakened ICI efficiency. Col1 receptor DDR1 could be a potential target synergically used with ICI to overcome ECM mediated ICI resistance. These provide a mechanical insight and novel strategy to overcome the ICI resistance of HCC.

Postoperative serum osteopontin level is a novel monitor for treatment response and tumor recurrence after resection of hepatitis B-related hepatocellular carcinoma.

BACKGROUND: Presurgery serum osteopontin (OPN) level has been demonstrated to correlate to tumor recurrence and survival of hepatocellular carcinoma (HCC) patients. This study investigated the postoperative dynamic changes of serum OPN level and its clinical significance in HCC patients. METHODS: Presurgery serum OPN levels were measured by enzyme-linked immunosorbent assay in cohort A of 179 HCC patients and were compared with the multiple controls including different kinds of liver diseases and healthy individuals. In cohort B of 110 patients with resectable HCCs, besides preoperative assays, serum OPN was monitored at 1 week, 1, and ≥2 months after operation. RESULTS: The baseline presurgery serum OPN of HCC patients was significantly higher than that of the patients with the other kinds of liver diseases (p < 0.0001). The prognostic values of presurgery serum OPN level in HCC patients were further confirmed. The postsurgery OPN levels were significantly elevated within 1 week after HCC resection, then decreased at 1 month and reached the nadir later than 2 months after operations. It increased again at the time of tumor recurrence, then declined after the second removal of recurrent HCCs. Moreover, postoperative OPN in α-fetoprotein-negative and -positive HCC patients had the same changing pattern; it only correlated to liver function and C-reactive protein level. CONCLUSIONS: After a transient fluctuation, serum OPN levels significantly decrease after curative resection of HCCs. Postoperative serum OPN could serve as a surrogate serologic biomarker for monitoring treatment response and tumor recurrence after HCC resection, including α-fetoprotein-negative ones.

Development and validation of a mutation-annotated prognostic score for intrahepatic cholangiocarcinoma after resection: a retrospective cohort study.

BACKGROUND: The value of existing prognostic models for intrahepatic cholangiocarcinoma is limited. The inclusion of prognostic gene mutations would enhance the predictive efficacy. METHODS: In the screening cohorts, univariable Cox regression analysis was applied to investigate the effect of individual mutant genes on overall survival (OS). In the training set, multivariable analysis was performed to evaluate the independent prognostic roles of the clinicopathological and mutational parameters, and a prognostic model was constructed. Internal and external validations were conducted to evaluate the performance of this model. RESULTS: Among the recurrent mutations, only TP53 and KRASG12 were significantly associated with OS across all three screening cohorts. In the training cohort, TP53 and KRASG12 mutations in combination with seven other clinical parameters (tumor size, tumor number, vascular invasion, lymph node metastasis, adjacent invasion, CA19-9, and CEA), were independent prognostic factors for OS. A mutation-annotated prognostic score (MAPS) was established based on the nine prognosticators. The C-indices of MAPS (0.782 and 0.731 in the internal and external validation cohorts, respectively) were statistically higher than those of other existing models ( P <0.05). Furthermore, the MAPS model also demonstrated significant value in predicting the possible benefits of upfront surgery and adjuvant therapy. CONCLUSIONS: The MAPS model demonstrated good performance in predicting the OS of intrahepatic cholangiocarcinoma patients. It may also help predict the possible benefits of upfront surgery and adjuvant therapy.

Targeting IRG1 reverses the immunosuppressive function of tumor-associated macrophages and enhances cancer immunotherapy.

Immune-responsive gene 1 (IRG1) encodes aconitate decarboxylase (ACOD1) that catalyzes the production of itaconic acids (ITAs). The anti-inflammatory function of IRG1/ITA has been established in multiple pathogen models, but very little is known in cancer. Here, we show that IRG1 is expressed in tumor-associated macrophages (TAMs) in both human and mouse tumors. Mechanistically, tumor cells induce Irg1 expression in macrophages by activating NF-κB pathway, and ITA produced by ACOD1 inhibits TET DNA dioxygenases to dampen the expression of inflammatory genes and the infiltration of CD8+ T cells into tumor sites. Deletion of Irg1 in mice suppresses the growth of multiple tumor types and enhances the efficacy of anti-PD-(L)1 immunotherapy. Our study provides a proof of concept that ACOD1 is a potential target for immune-oncology drugs and IRG1-deficient macrophages represent a potent cell therapy strategy for cancer treatment even in pancreatic tumors that are resistant to T cell-based immunotherapy.

Neutrophil extracellular traps in hepatocellular carcinoma are enriched in oxidized mitochondrial DNA which is highly pro-inflammatory and pro-metastatic.

Background: Neutrophil extracellular traps (NETs) are net like extracellular structure formed by neutrophils in response to certain stimulation. It works as inflammatory regulator and metastasis promoter in cancer. Mitochondrial-(mt)DNA is a circular, mitochondria derived double strain molecule, which is involved in NETs formation. Its role in NETs induced inflammatory alteration in hepatocellular carcinoma (HCC) remained unexplored. Method: We evaluated the mitochondrial reactive oxygen species (mitoROS) level in peripheral neutrophils from HCC patients and the oxidative level of mtDNA in derived NETs. The association between the NETs and oxidized mtDNA was assessed to reveal their relevance. A function assay was applied to uncover how the oxidation state of mtDNA directed the metastasis promoting inflammation state in HCC cells in a NETs protein dependent manner. Finally, using animal models, we explored the potential of a therapy strategy against NETs-drove metastasis by targeting the oxidized mtDNA with metformin. Results: Neutrophils in HCC patients contained high level of mitoROS level, and formed NETs that were enriched in oxidized mtDNA in a mitoROS dependent manner. NETs and oxidized mtDNA were clinically relevant. Bound with NETs protein, oxidized mtDNA is more capable of triggering the metastasis-promoting inflammatory mediators in HepG2 cells. Targeting the oxidized mtDNA with metformin attenuated the metastasis-promoting inflammatory state and hereby undermine the metastasis capacity of HCC. Conclusion: HCC is capable to stimulate NETs enriched in oxidized mtDNA, which are highly pro-inflammatory and pro-metastatic. Oxidized mtDNA in NETs may serve as a potential anti-metastatic target by metformin therapy.

Cancer-derived exosomal HSPC111 promotes colorectal cancer liver metastasis by reprogramming lipid metabolism in cancer-associated fibroblasts.

Tumor metastasis is a hallmark of cancer. The communication between cancer-derived exosomes and stroma plays an irreplaceable role in facilitating pre-metastatic niche formation and cancer metastasis. However, the mechanisms underlying exosome-mediated pre-metastatic niche formation during colorectal cancer (CRC) liver metastasis remain incompletely understood. Here we identified HSPC111 was the leading upregulated gene in hepatic stellate cells (HSCs) incubated with CRC cell-derived exosomes. In xenograft mouse model, CRC cell-derived exosomal HSPC111 facilitated pre-metastatic niche formation and CRC liver metastases (CRLM). Consistently, CRC patients with liver metastasis had higher level of HSPC111 in serum exosomes, primary tumors and cancer-associated fibroblasts (CAFs) in liver metastasis than those without. Mechanistically, HSPC111 altered lipid metabolism of CAFs by phosphorylating ATP-citrate lyase (ACLY), which upregulated the level of acetyl-CoA. The accumulation of acetyl-CoA further promoted CXCL5 expression and secretion by increasing H3K27 acetylation in CAFs. Moreover, CXCL5-CXCR2 axis reinforced exosomal HSPC111 excretion from CRC cells and promoted liver metastasis. These results uncovered that CRC cell-derived exosomal HSPC111 promotes pre-metastatic niche formation and CRLM via reprogramming lipid metabolism in CAFs, and implicate HSPC111 may be a potential therapeutic target for preventing CRLM.

Cholesterol suppresses GOLM1-dependent selective autophagy of RTKs in hepatocellular carcinoma.

Aberrant activation of receptor tyrosine kinases (RTKs) and the subsequent metabolic reprogramming play critical roles in cancer progression. Our previous study has shown that Golgi membrane protein 1 (GOLM1) promotes hepatocellular carcinoma (HCC) metastasis by enhancing the recycling of RTKs. However, how this RTK recycling process is regulated and coupled with RTK degradation remains poorly defined. Here, we demonstrate that cholesterol suppresses the autophagic degradation of RTKs in a GOLM1-dependent manner. Further mechanistic studies reveal that GOLM1 mediates the selective autophagy of RTKs by interacting with LC3 through an LC3-interacting region (LIR), which is regulated by a cholesterol-mTORC1 axis. Lowering cholesterol by statins improves the efficacy of multiple tyrosine kinase inhibitors (TKIs) in vivo. Our findings indicate that cholesterol serves as a signal to switch GOLM1-RTK degradation to GOLM1-RTK recycling and suggest that lowering cholesterol by statin may be a promising combination strategy to improve the TKI efficiency in HCC.

Driver mutations of intrahepatic cholangiocarcinoma shape clinically relevant genomic clusters with distinct molecular features and therapeutic vulnerabilities.

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.

Organ-specific cholesterol metabolic aberration fuels liver metastasis of colorectal cancer.

Rationale: Metastasis, the development of secondary malignant growth at a distance from a primary tumor, is the main cause of cancer-associated death. However, little is known about how metastatic cancer cells adapt to and colonize in the new organ environment. Here we sought to investigate the functional mechanism of cholesterol metabolic aberration in colorectal carcinoma (CRC) liver metastasis. Methods: The expression of cholesterol metabolism-related genes in primary colorectal tumors (PT) and paired liver metastases (LM) were examined by RT-PCR. The role of SREBP2-dependent cholesterol biosynthesis pathway in cell growth and CRC liver metastasis were determined by SREBP2 silencing in CRC cell lines and experimental metastasis models including, intra-splenic injection models and liver orthotropic injection model. Growth factors treatment and co-culture experiment were performed to reveal the mechanism underlying the up-regulation of SREBP2 in CRC liver metastases. The in vivo efficacy of inhibition of cholesterol biosynthesis pathway by betulin or simvastatin were evaluated in experimental metastasis models. Results: In the present study, we identify a colorectal cancer (CRC) liver metastasis-specific cholesterol metabolic pathway involving the activation of SREBP2-dependent cholesterol biosynthesis, which is required for the colonization and growth of metastatic CRC cells in the liver. Inhibiting this cholesterol biosynthesis pathway suppresses CRC liver metastasis. Mechanically, hepatocyte growth factor (HGF) from liver environment activates SREBP2-dependent cholesterol biosynthesis pathway by activating c-Met/PI3K/AKT/mTOR axis in CRC cells. Conclusion: Our findings support the notion that CRC liver metastases show a specific cholesterol metabolic aberration. Targeting this cholesterol biosynthesis pathway could be a promising treatment for CRC liver metastasis.