Identification of a bile acid and bile salt metabolism-related lncRNA signature for predicting prognosis and treatment response in hepatocellular carcinoma

Review of the mechanisms of the biliary-enteric axis in the development of cholangiocarcinoma

Cholangiocarcinoma (CCA) is a particularly aggressive and challenging type of cancer, known for its poor prognosis, which is worsened by the complex interplay of various biological and environmental factors that contribute to its development. Recently, researchers have increasingly focused on the significant role of the biliary-enteric communication of liver-gut axis in the pathogenesis of CCA, highlighting a complex relationship that has not been thoroughly explored before. This review aims to summarize the key concepts related to the biliary-enteric communication of liver-gut axis and investigate its potential mechanisms that may lead to the onset and progression of CCA, a disease that presents substantial treatment challenges. Important areas of focus will include the microbiome's profound influence, which interacts with host physiology in ways that may worsen cancer development; changes in bile acid metabolism that can create toxic environments favorable for tumor growth; the regulation of inflammatory processes that may either promote or inhibit tumor progression; the immune system's involvement, which is crucial in the body's response to cancer; and the complex interactions within metabolic pathways that can affect cellular behavior and tumor dynamics. By integrating recent research findings from various studies, we aim to explore the multifaceted roles of the biliary-enteric communication of liver-gut axis in CCA, providing new insights and perspectives for future research while identifying promising therapeutic targets that could lead to innovative treatment strategies aimed at improving patient outcomes in this challenging disease.

The oncogenic role and prognostic value of PXDN in human stomach adenocarcinoma

Stomach adenocarcinoma (STAD) is known for its high prevalence and poor prognosis, which underscores the need for novel therapeutic targets. Peroxidasin (PXDN), an enzyme with peroxidase activity, has been linked to cancer development in previous studies. However, its specific role in STAD is not well understood. In our study, we used public databases and clinical specimens to determine that PXDN expression is significantly elevated in STAD tissues and serves as an independent prognostic marker for patient outcomes. Our in vitro assays demonstrated that silencing PXDN significantly reduced STAD cell proliferation, invasion, and migration. Mechanistically, we found that PXDN promotes epithelial‒mesenchymal transition and angiogenesis in STAD cells and may be regulated by the PI3K/AKT pathway. Further analysis revealed that PXDN levels affect the sensitivity of STAD cells to various chemotherapeutic and small molecule drugs. Additionally, we observed a significant association between PXDN levels and the abundances of various immune cell types in patients with STAD. Our study highlighted a strong link between PXDN levels and the tumor immune microenvironment (TIM), suggesting that PXDN is a useful metric for evaluating the response to immune checkpoint inhibitors. Moreover, we found that PXDN is significantly associated with multiple immune checkpoints. In summary, our findings indicate that PXDN plays a critical role in STAD and that its level could serve as a potential prognostic biomarker. Thus, targeting PXDN may represent an effective treatment strategy for STAD.

Bile acid conjugated chitosan nanoparticles promote the proliferation and epithelial-mesenchymal transition of hepatocellular carcinoma by regulating the PI3K/Akt/mTOR pathway

Bile acids have been known to play significant roles at certain physiological levels in gastrointestinal metabolism. Yet, they are known to be carcinogenic and aid in tumor progression in most cases, although the roles remain uncertain. Hence, we tested the cytotoxic potential of cholic acid (CA) loaded chitosan nanoparticles (CNPs) on Hep3B cells. The physicochemical properties of the CNPs synthesized with CA load (CA-CNPs) were determined using standard techniques such as ultraviolet-visible spectrophotometry (UV-Vis), fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), dynamic light scattering (DLS) and transmission electron microscopy (TEM). The characteristic peak for chitosan nanoparticles were observed for plain CNPs (pCNPs) and CA-CNPs at around 300 nm as per UV-Vis analysis. FTIR analysis indicated the possible trapping of CA onto CNPs as certain peaks were retained and some peaks were shifted. XRD analysis determined that the peaks representing CA and pCNPs were collectively obtained in CA-CNPs. As per DLS analysis, the particle size, PDI and ζ-potential of the CA-CNPs were 259 nm, 0.284 and 30.4 mV. Further, the CA-CNPs were non-cytotoxic on Hep3B cells at the maximum tested concentration of 500 μg/mL. The viability at 500 μg/mL of CA-CNPs was two-fold higher than 500 μg/mL of pCNPs. Also, the pCNPs were not hemolytic and therefore could not have played a role in the increase of viability after treatment with CA-CNPs, which indicates that CA posed a major role in increased viability of Hep3B cells. As per quantitative PCR (qPCR), the upregulated gene expressions of PI3K, Akt, mTORC2, cMyc, Fibronectin, hVPS34, Slug and ZEB1 and the downregulated expression of the tumor suppressor PTEN indicates that PI3K/Akt/mTOR pathway mediated the induction of epithelial-to-mesenchymal transition (EMT) in response to CA-CNPs treatment on Hep3B cells.

The liquid-liquid phase separation signature predicts the prognosis and immunotherapy response in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a common and fatal malignancy characterized by poor patient prognosis and treatment outcome. The process of liquid-liquid phase separation in tumour cells alters the dysfunction of biomolecular condensation in tumour cells, which affects tumour progression and treatment. We downloaded the data of HCC samples from TCGA database and GEO database, and used a machine learning method to build a new liquid-liquid phase separation index (LLPSI) by liquid-liquid phase separation related genes. The LLPSI-related column line Figure was constructed to provide a quantitative tool for clinical practice. HCC patients were divided into high and low LLPSI groups based on LLPSI, and clinical features, tumour immune microenvironment, chemotherapeutic response, and immunotherapeutic response were systematically analysed. LLPSI, which consists of five liquid-liquid phase separation-associated genes (MAPT, WDR62, PLK1, CDCA8 and TOP2A), is a reliable predictor of survival in patients with HCC and has been validated in multiple external datasets. We found that the high LLPSI group showed higher levels of immune cell infiltration and better response to immunotherapy compared to the low LLPSI group, and LLPSI can also be used for prognostic prediction in various cancers other than HCC. In vitro experiments verified that knockdown of MAPT could inhibit the proliferation and migration of HCC. The LLPSI identified in this study can accurately assess the prognosis of patients with HCC and identify patient populations that will benefit from immunotherapy, providing valuable insights into the clinical management of HCC.

Sex Dimorphic Effects of Bile Acid Metabolism in Liver Cancer in Mice

BACKGROUND & AIMS

Hepatocellular carcinoma (HCC) is a male-dominant disease, but targeted sex hormone therapies have not been successful. Bile acids are a potential liver carcinogen and are biomolecules with hormone-like effects. A few studies highlight their potential sex dimorphism in physiology and disease. We hypothesized that bile acids could be a potential molecular signature that explains sex disparity in HCC.

METHODS & RESULTS

We used the farnesoid X receptor knockout (FxrKO) mouse model to study bile acid-dependent HCC. Temporal tracking of circulating bile acids determined more than 80% of FxrKO females developed spontaneous cholemia (ie, serum total bile acids ≥40 μmol/L) as early as 8 weeks old. Opposingly, FxrKO males were highly resistant to cholemia, with ∼23% incidence even when 26 weeks old. However, FxrKO males demonstrated higher levels of deoxycholate than females. Compared with males, FxrKO females had more severe cholestatic liver injury and further aberrancies in bile acid metabolism. Yet, FxrKO females expressed more detoxification transcripts and had greater renal excretion of bile acids. Intervention with CYP7A1 (rate limiting enzyme for bile acid biosynthesis) deficiency or taurine supplementation either completely or partially normalized bile acid levels and liver injury in FxrKO females. Despite higher cholemia prevalence in FxrKO females, their tumor burden was less compared with FxrKO males. An exception to this sex-dimorphic pattern was found in a subset of male and female FxrKO mice born with congenital cholemia due to portosystemic shunt, where both sexes had comparable robust HCC.

CONCLUSIONS

Our study highlights bile acids as sex-dimorphic metabolites in HCC except in the case of portosystemic shunt.