Sortilin-Driven Cancer Secretome Enhances Tumorigenic Properties of Hepatocellular Carcinoma via de Novo Lipogenesis.

A growing body of evidence suggests de novo lipogenesis as a key metabolic pathway adopted by cancers to fuel tumorigenic processes. While increased de novo lipogenesis has also been reported in hepatocellular carcinoma (HCC), understanding on molecular mechanisms driving de novo lipogenesis remains limited. In the present study, the functional role of sortilin, a member of the vacuolar protein sorting 10 protein receptor family, in HCC was investigated. Sortilin was overexpressed in HCC and was associated with poorer survival outcome. In functional studies, sortilin-overexpressing cells conferred tumorigenic phenotypes, namely, self-renewal and metastatic potential, of HCC cells via the cancer secretome. Proteomic profiling highlighted fatty acid metabolism as a potential molecular pathway associated with sortilin-driven cancer secretome. This finding was validated by the increased lipid content and expression of fatty acid synthase (FASN) in HCC cells treated with conditioned medium collected from sortilin-overexpressing cells. The enhanced tumorigenic properties endowed by sortilin-driven cancer secretome were partly abrogated by co-administration of FASN inhibitor C75. Further mechanistic dissection suggested protein stabilization by post-translational modification with O-GlcNAcylation as a major mechanism leading to augmented FASN expression. In conclusion, the present study uncovered the role of sortilin in hepatocarcinogenesis via modulation of the cancer secretome and deregulated lipid metabolism.

Stanniocalcin 1 is a serum biomarker and potential therapeutic target for HBV-associated liver fibrosis.

Stanniocalcin 1 (STC1), a secreted protein, is upregulated in human cancers including hepatocellular carcinoma (HCC). While most HCCs develop from chronic liver disease, which involves progressive parenchymal injury and fibrosis, the role of STC1 in this preneoplastic stage remains poorly understood. In this study we investigated the clinical relevance and functional significance of secreted STC1 in liver fibrosis. To this end, the STC1 level was determined in the serum samples of chronic hepatitis B patients and correlated with the degree of liver fibrosis. Diagnostic performance of STC1 was analysed by area under the receiver operating characteristic curve (AUROC), sensitivity, specificity, positive predictive value, and negative predictive value. The results were compared with other well-characterised serum biomarkers for liver fibrosis: Aspartate transaminase to Platelet Ratio Index (APRI) and Fibrosis-4 (FIB-4). The functional role of STC1 was interrogated by in vitro experiments using cell line models. Expression of fibrogenic markers was quantified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blotting. Our results showed that the serum STC1 level in chronic hepatitis B patients was positively correlated with the degree of liver fibrosis and showed a stepwise increase in accordance with the severity of fibrosis. The AUROCs for detecting significant fibrosis (>9.0 kPa) and cirrhosis (>12.0 kPa) was 0.911 and 0.880, respectively. STC1 demonstrated a superior specificity and positive predictive value when compared to APRI and FIB-4. Consistent with this, STC1 was elevated in the liver tissues and sera of CCl4 -treated mice showing marked liver fibrosis. In vitro, STC1 was secreted by the human hepatic stellate cell line LX2. Human recombinant STC1 (rhSTC1) induced expression of fibrogenic markers in LX2 cells. The profibrogenic phenotype conferred by rhSTC1 or TGF-ß1 in LX2 cells could be attenuated using anti-STC1 antibody. Taken together, STC1 is a specific serum biomarker for HBV-associated liver fibrosis. STC1 functionally promotes liver fibrogenesis and is a potential actionable target. © 2022 The Pathological Society of Great Britain and Ireland.

Anti-tumour effects of PIM kinase inhibition on progression and chemoresistance of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a biologically aggressive cancer. Targeted therapy is in need to tackle challenges in the treatment perspective. A growing body of evidence suggests a promising role of pharmacological inhibition of PIM (proviral integration site for Moloney murine leukaemia virus) kinase in some human haematological and solid cancers. Yet to date, the potential application of PIM inhibitors in HCC is still largely unexplored. In the present study we investigated the pre-clinical efficacy of PIM inhibition as a therapeutic approach in HCC. Effects of PIM inhibitors on cell proliferation, migration, invasion, chemosensitivity, and self-renewal were examined in vitro. The effects of PIM inhibitors on tumour growth and chemoresistance in vivo were studied using xenograft mouse models. Potential downstream molecular mechanisms were elucidated by RNA sequencing (RNA-seq) of tumour tissues harvested from animal models. Our findings demonstrate that PIM inhibitors SGI-1776 and PIM447 reduced HCC proliferation, metastatic potential, and self-renewal in vitro. Results from in vivo experiments supported the role of PIM inhibition in suppressing of tumour growth and increasing chemosensitivity of HCC toward cisplatin and doxorubicin, the two commonly used chemotherapeutic agents in trans-arterial chemoembolisation (TACE) for HCC. RNA-seq analysis revealed downregulation of the MAPK/ERK pathway upon PIM inhibition in HCC cells. In addition, LOXL2 and ICAM1 were identified as potential downstream effectors. Taken together, PIM inhibitors demonstrated remarkable anti-tumourigenic effects in HCC in vitro and in vivo. PIM kinase inhibition is a potential approach to be exploited in formulating adjuvant therapy for HCC patients of different disease stages. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Sex-specific analysis of microRNA profiles in HBV-associated cirrhosis by small RNA-sequencing.

Liver cirrhosis represents an advanced stage of chronic liver disease and is associated with significant morbidity, mortality, and risk of cancer development. While sex disparity of liver diseases has been observed, understanding at a genetic level awaits more thorough investigation. In this study, we performed a sex-specific analysis of the microRNA (miR) profiles in hepatitis B virus (HBV)-associated cirrhosis by small RNA-sequencing using clinical tissue samples. Potential associated signaling pathways, downstream gene targets, and upstream regulators were highlighted by computational prediction analyses based on the differentially expressed miRs (DEmiRs). From our results, deregulation of miRs in cirrhosis showed a marked difference between males and females by the degree and pattern. Sixty-five (64 up-regulated, 1 down-regulated) and 12 (6 up-regulated, 6 down-regulated) DEmiRs were found in males and females, respectively, when compared with their respective control group. A number of DEmiRs were only observed in one sex but not the other. In addition, 26 DEmiRs were identified between cirrhosis female and cirrhosis male groups. Fatty acid biosynthesis pathway, extracellular matrix-receptor interaction, p53 signaling, Hippo signaling, tumor necrosis factor signaling, the forkhead box O signaling, as well as gene targets ribosomal protein S27 like, methyl CpG binding protein 2, and estrogen receptor 1, may contribute to the pathogenesis and biological behavior of cirrhosis in a sex-specific manner. Analysis of the Cancer Genome Atlas data set suggested a role of sex-specific DEmiRs in multistep hepatocarcinogenesis. Conclusion: Our findings illustrate that miR profiles in HBV-associated cirrhosis are distinct between the males and females and suggest a potential role of sex-specific biomarkers and molecular mechanisms in disease development and progression.

An Immunohistochemical Study of ß-catenin Expression and Immune Cell Population in Metastatic Carcinoma to the Liver.

The liver is the commonest site of cancer metastasis. In this study, we asked whether the immune tumor microenvironment in liver metastases was governed by the ß-catenin activation status of the tumor. To this end, we analyzed CD8 and FoxP3 immunohistochemical expression against ß-catenin expression status of the tumor in a cohort of 52 liver samples with metastatic carcinoma. The results showed that colorectal primary constituted the largest proportion of metastatic carcinoma showing ß-catenin overexpression. Intra-tumoral CD8 count was lower and FoxP3 count was higher when compared with the non-tumoral liver parenchyma. ß-catenin overexpression was associated with a lower CD8 count in the tumor region (p = 0.003). In summary, our findings are in support of an altered immune tumor microenvironment vs. the non-tumor liver tissues in the metastatic site. Suppression of CD8 count was associated with activated Wnt/ß-catenin signaling in the metastatic tumor.

A Clinicopathological Study of Young-onset Hepatocellular Carcinoma.

BACKGROUND/AIM: The aim of this study was to describe the clinicopathological features of hepatocellular carcinoma (HCC) diagnosed at 40 years of age or below. MATERIALS AND METHODS: Expression of CK19, Glypican-3 and ß-catenin was assessed in clinical samples by immunohistochemistry (IHC). IHC expression was correlated with clinicopathological parameters. Hotspot mutations in TP53 gene were analyzed by sequencing. RESULTS: Thirty-six cases were included with a male to female ratio of 3:1. Eighty percent of cases were associated with chronic hepatitis B infection. CK19 and GPC3 were expressed in 61% and 56% of cases, respectively. Only one case demonstrated ß-catenin over-expression. TP53 hotspot mutation was identified in 4 cases. Number of tumor nodules, vascular invasion, and preoperative serum AFP level were associated with prognosis. CONCLUSION: A higher CK19 expression rate was observed in our young-onset HCC cohort, whereas ß-catenin pathway activation and TP53 gene mutation events were less frequent. Conventional clinicopathological parameters remain predictors of survival.