Novel Molecular Targets for Immune Surveillance of Hepatocellular Carcinoma

A novel phosphodiesterase target as a therapeutic approach: inhibiting DEN-induced hepatocellular carcinoma progression

Hepatocellular Carcinoma (HCC) is one of the most common and fatal types of liver cancer worldwide; in this sense, Diethylnitrosamine (DEN) has been established as a potent carcinogen affecting the development and progression of this disease. The present work focused on determining whether phosphodiesterase (PDE) enzymes, especially PDE5, may serve as targets in the therapeutic treatment of DEN-induced HCC. PDE5 inhibitors, widely used as therapeutic drugs for cardiovascular diseases and erectile dysfunction, have recently been found to be promising in preclinical cancer models through the modulation of key signaling pathways implicated in the progression of tumors, such as the cGMP-PKG, JNK, and MAPK pathways. These pathways are very important for cell proliferation, apoptosis and metastasis, and their dysregulation contributes to the aggressive nature of HCC. This study assessed the potential of PDE5 inhibitors to suppress proliferation, induce apoptosis, and alter the tumor microenvironment, thus potentially improving standard chemotherapy and immunotherapy interventions. By inhibiting certain PDE isoforms with these drugs, an anticancer response might occur as part of a complex mechanism that acts on both cancer cells and the microenvironment favorable for tumor growth. A preliminary review indicated that PDE inhibitors may be a promising therapeutic approach for overcoming some of the shortcomings of current treatments, particularly the development of resistance and the toxic effects of these treatments. Additional clinical investigations are necessary to determine the safety profile, appropriate amount of Osage, and long-term efficacy of these agents in the treatment of HCC, particularly in DEN-induced animal models. This study contributes to the expanding body of evidence supporting the use of PDE inhibitors in cancer treatment.

Harnessing nanoparticles for reshaping tumor immune microenvironment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most prevalent cancers, characterized by high morbidity and mortality rates. Recently, immunotherapy has emerged as a crucial treatment modality for HCC, following surgery, locoregional therapies, and targeted therapies. This approach harnesses the body's immune system to target and eliminate cancer cells, potentially resulting in durable antitumor responses. However, acquired resistance and the tumor immunosuppressive microenvironment (TIME) significantly hinder its clinical application. Recently, advancements in nanotechnology, coupled with a deeper understanding of cancer biology and nano-biological interactions, have led to the development of various nanoparticles aimed at enhancing therapeutic efficacy through specific targeting of tumor tissues. These nanoparticles increase the accumulation of immunotherapeutic drugs within the tumor microenvironment, thereby transforming the TIME. In this review, we provide a concise overview of the fundamental principles governing the TIME landscape in HCC and discuss the rationale for and applications of nanoparticles in this context. Additionally, we highlight existing challenges and potential opportunities for the clinical translation of cancer nanomedicines.

Protease activated receptor 2 as a novel druggable target for the treatment of metabolic dysfunction-associated fatty liver disease and cancer

Metabolic dysfunction-associated fatty liver disease (MAFLD) is spreading worldwide, largely due to unhealthy lifestyles that contribute to the rise in diabetes, metabolic syndrome, and obesity. In this situation, the progression of injury to metabolic steatohepatitis can evolve to cirrhosis and, eventually, to hepatocellular carcinoma (HCC). It is well known that serine protease enzymes with different functions in cellular homeostasis act as signaling molecules that regulate liver inflammation by activating the protease-activated receptors (PARs) family members, expressed on the cellular plasma membrane. Among them, PAR2 plays a central role in the activation of signaling pathways in response to changes in the extracellular microenvironment. Experimental data have provided evidence that PAR2 is involved not only in inflammatory response but also in insulin resistance, lipid metabolism, and cancer. The major aims of this narrative review are addressed to assess PAR2 involvement in inflammation, metabolism, and liver disease progression and to explore possible therapeutic strategies, based on PAR2 inhibition, in order to prevent its biological effects in the context of MAFLD and cancer.

The polymorphic variant of SerpinB3 (SerpinB3-PD) is associated with faster cirrhosis decompensation

BACKGROUND

SerpinB3 is a cysteine protease inhibitor involved in liver disease progression due to its proinflammatory and profibrogenic properties. The polymorphic variant SerpinB3-PD (SB3-PD), presents a substitution in its reactive centre loop, determining the gain of function.

AIMS

To disclose the clinical characteristics of a cohort of patients with cirrhosis in relation to the presence of SB3-PD and to assess the effect of this genetic variant on fibrogenic and inflammatory cytokines in vitro.

METHODS

We assessed SB3 polymorphism in 90 patients with cirrhosis, prospectively followed up in our referral centre. We used HepG2 and HuH-7 cells transfected to overexpress either wild-type SB3 (SB3-WT) or SB3-PD to assess their endogenous effect, while LX2 and THP-1 cells were treated with exogenous SB3-WT or SB3-PD proteins.

RESULTS

Patients carrying SB3-PD had more severe portal hypertension and higher MELD scores, than patients carrying SB3-WT. In multivariate analysis, SB3-PD was an independent predictor of cirrhosis complications. Patients with SB3-PD polymorphism presented with more severe liver fibrosis and inflammatory features. Hepatoma cells overexpressing SB3-PD showed higher TGF-β1 expression than controls. The addition of recombinant SB3-PD induced an up-regulation of TGF-β1 in LX2 cells and a more prominent inflammatory profile in THP-1 cells, compared to the effect of SB3-WT protein.

CONCLUSIONS

The polymorphic variant SB3-PD is highly effective in determining activation of TGF-β1 and inflammation in vitro. Patients with cirrhosis who carry SB3-PD polymorphism may be more prone to develop severe liver disease progression. However, further validation studies are warranted to support the in vivo relevance of this polymorphism.