The primary malignancy of liver, known as hepatocellular carcinoma (HCC), comprises 9% of all hepatobiliary carcinomas. A steady rise has also been observed in adenocarcinoma (ADC) of the liver and ampullary carcinoma (AMC), ascending to 0.5% of gastrointestinal malignancies. Hepatobiliary carcinomas consist of 13% of all cancer occurrences worldwide. Purinergic receptor-based signaling holds the therapeutic potential based on its role in cell proliferation of several carcinomas. An altered ATP concentration in nanomoles may lead towards crucial changes in cancer growth patterns in liver tissue. A total of 40 tissue samples were collected (20 samples of HCC, 10 samples of ADC, and 10 samples of AMC) from patients that underwent surgery. P2X4 and P2X7 receptors exhibited significantly increased expression in HCC, ADC, and AMC samples as compared with the control tissue samples. While ADC and AMC samples showed higher expression of P2X4 and P2X7 than the control, statistically, HCC samples exhibited the most significant expression of both P2X4 and P2X7 receptors than control tissues. It may be inferred that higher expression of P2X4 and P2X7 receptors is significantly associated with the upregulated cellular stress leading to inflammation and it is plausible that both these receptors may be used in diagnostic, prognostic, and therapeutic tools for carcinoma studies in the future.
Extracellular ATP-induced Ca2+ signalling is critical in regulating diverse physiological and disease processes. Emerging evidence suggests high concentrations of extracellular ATP in tumour tissues. In this study, we examined the P2 receptor for ATP-induced Ca2+ signalling in human hepatocellular carcinoma (HCC) cells. Fura-2-based measurements of the intracellular Ca2+ concentration ([Ca2+]i) showed that extracellular ATP induced an increase in the [Ca2+]i in human HCC Huh-7 and HepG2 cells. NF546, a P2Y11 receptor agonist was equally effective in inducing an increase in the [Ca2+]i. In contrast, agonists for the P2X receptors (αβmeATP and BzATP), P2Y1 receptor (MRS2365) or P2Y2 receptor (MRS2768) were ineffective. In addition, ATP/NF546-induced increases in the [Ca2+]i were strongly inhibited by treatment with NF340, a P2Y11 receptor antagonist. Immunofluorescent confocal imaging and western blotting analysis consistently demonstrated the P2Y11 receptor expression in Huh-7 and HepG2 cells. Transfection with P2Y11-specific siRNA attenuated the P2Y11 receptor protein expression level and also reduced NF546-induced increase in the [Ca2+]i. Importantly, immunohistochemistry revealed that the P2Y11 receptor was expressed at very high level in human HCC tissues and, by contrast, it was barely detected in normal liver tissues. Trans-well cell migration assay demonstrated that ATP and NF546 induced concentration-dependent stimulation of Huh-7 cell migration. Treatment with NF340 prevented ATP-induced stimulation of cell migration. Taken together, our results show carcinoma-specific expression of the P2Y11 receptor and its critical role in mediating ATP-inducing Ca2+ signalling and regulating cell migration in human HCC cells.
Purinergic P2X receptors are plasma membrane bound, ATP-gated ion channels that are expressed on wide range of cells and respond to varying ATP concentrations in extracellular environment. Upon activation they increase membrane permeability for Ca(2+) ions and trigger a cascade of signaling complexes. During the course of hepatitis C virus (HCV) infection, ATP is released from the infected hepatocyte, which binds with Purinergic receptors (P2X) on peripheral blood mononuclear cells (PBMCs) and initiate downstream signaling pathways by disturbing the ionic balance of the cell. The present study investigates quantitative expression of P2X7 and P2X4 along with selected host genes PEPCK, transforming growth factor β (TGF-β), MAPK, Rho, and Akt in PBMCs of chronic HCV infection patients. PBMCs were isolated from collected blood samples of study subjects. Transcript analysis of P2X7, P2X4, and targeted downstream genes was done using quantitative real-time polymerase chain reaction. Relative expression analysis was performed by unpaired Student's t test on GraphPad Prism version 5. We found a notable increase of threefolds and 1.8-folds in the expression of P2X7 and P2X4 receptors in treatment naïve category while the expression of PEPCK, TGF-β, MAPK, AKT, and Rho A increased by 2.8, 1.9, 2.2, 2.2, and 1.8-folds, respectively. In sustained virological response patients, P2X7 significantly increased up to 3.5-folds while the expression of P2X4 receptor was increased up to twofold. In third category, treatment nonresponder, the expression of P2X7, P2X4 receptors, and targeted markers remained un-altered. This study deals with two major aspects of P2X4 and P2X7 receptors in PBMCs of chronic HCV individuals. One is their role in providing antiviral immunity to host against HCV; second aspect is the role of P2X receptors in inducing HCV pathogenesis via AKT, TGF-β, Rho A, PEPCK, and MAPK expression.
The current standard of care (SOC) for hepatitis C virus (HCV) infection is the combination of pegylated interferon (PEG-IFN), Ribavirin and protease inhibitor for HCV genotype 1. Nevertheless, this treatment is successful only in 70-80% of the patients. In addition, the treatment is not economical and is of immense physical burden for the subject. It has been established now, that virus-host interactions play a significant role in determining treatment outcomes. Therefore identifying biological markers that may predict the treatment response and hence treatment outcome would be useful. Both IFN and Ribavirin mainly act by modulating the immune system of the patient. Therefore, the treatment response is influenced by genetic variations of the human as well as the HCV genome. The goal of this review article is to summarize the impact of recent scientific advances in this area regarding the understanding of human and HCV genetic variations and their effect on treatment outcomes. Google scholar and PubMed have been used for literature research. Among the host factors, the most prominent associations are polymorphisms within the region of the interleukin 28B (IL28B) gene, but variations in other cytokine genes have also been linked with the treatment outcome. Among the viral factors, HCV genotypes are noteworthy. Moreover, for sustained virological responses (SVR), variations in core, p7, non-structural 2 (NS2), NS3 and NS5A genes are also important. However, all considered single nucleotide polymorphisms (SNPs) of IL28B and viral genotypes are the most important predictors for interferon based therapy of HCV infection.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.