Platelet-derived growth factor receptor α in hepatocellular carcinoma is a prognostic marker independent of underlying liver cirrhosis

Understanding Gene Involvement in Hepatocellular Carcinoma: Implications for Gene Therapy and Personalized Medicine

Hepatocellular carcinoma (HCC) is the dominant type of liver cancers and is one of the deadliest health threats globally. The conventional therapeutic options for HCC are hampered by low efficiency and intolerable side effects. Gene therapy, however, now offers hope for the treatment of many disorders previously considered incurable, and gene therapy is beginning to address many of the shortcomings of conventional therapies. Herein, we summarize the involvement of genes in the pathogenesis and prognosis of HCC, with a special focus on dysregulated signaling pathways, genes involved in immune evasion, and non-coding RNAs as novel two-edged players, which collectively offer potential targets for the gene therapy of HCC. Herein, the opportunities and challenges of HCC gene therapy are discussed. These include innovative therapies such as genome editing and cell therapies. Moreover, advanced gene delivery technologies that recruit nanomedicines for use in gene therapy for HCC are highlighted. Finally, suggestions are offered for improved clinical translation and future directions in this area of endeavor.

Hepatocellular Carcinoma: Old and Emerging Therapeutic Targets

Liver cancer, predominantly hepatocellular carcinoma (HCC), globally ranks sixth in incidence and third in cancer-related deaths. HCC risk factors include non-viral hepatitis, alcohol abuse, environmental exposures, and genetic factors. No specific genetic alterations are unequivocally linked to HCC tumorigenesis. Current standard therapies include surgical options, systemic chemotherapy, and kinase inhibitors, like sorafenib and regorafenib. Immunotherapy, targeting immune checkpoints, represents a promising avenue. FDA-approved checkpoint inhibitors, such as atezolizumab and pembrolizumab, show efficacy, and combination therapies enhance clinical responses. Despite this, the treatment of hepatocellular carcinoma (HCC) remains a challenge, as the complex tumor ecosystem and the immunosuppressive microenvironment associated with it hamper the efficacy of the available therapeutic approaches. This review explores current and advanced approaches to treat HCC, considering both known and new potential targets, especially derived from proteomic analysis, which is today considered as the most promising approach. Exploring novel strategies, this review discusses antibody drug conjugates (ADCs), chimeric antigen receptor T-cell therapy (CAR-T), and engineered antibodies. It then reports a systematic analysis of the main ligand/receptor pairs and molecular pathways reported to be overexpressed in tumor cells, highlighting their potential and limitations. Finally, it discusses TGFβ, one of the most promising targets of the HCC microenvironment.

Mutational Landscape and Precision Medicine in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fourth most common malignancy worldwide and exhibits a universal burden as the incidence of the disease continues to rise. In addition to curative-intent therapies such as liver resection and transplantation, locoregional and systemic therapy options also exist. However, existing treatments carry a dismal prognosis, often plagued with high recurrence and mortality. For this reason, understanding the tumor microenvironment and mutational pathophysiology has become the center of investigation for disease control. The use of precision medicine and genetic analysis can supplement current treatment modalities to promote individualized management of HCC. In the search for personalized medicine, tools such as next-generation sequencing have been used to identify unique tumor mutations and improve targeted therapies. Furthermore, investigations are underway for specific HCC biomarkers to augment the diagnosis of malignancy, the prediction of whether the tumor environment is amenable to available therapies, the surveillance of treatment response, the monitoring for disease recurrence, and even the identification of novel therapeutic opportunities. Understanding the mutational landscape and biomarkers of the disease is imperative for tailored management of the malignancy. In this review, we summarize the molecular targets of HCC and discuss the current role of precision medicine in the treatment of HCC.

N7-Methylguanosine Genes Related Prognostic Biomarker in Hepatocellular Carcinoma

Background: About 90% of liver cancer-related deaths are caused by hepatocellular carcinoma (HCC). N7-methylguanosine (m7G) modification is associated with the biological process and regulation of various diseases. To the best of our knowledge, its role in the pathogenesis and prognosis of HCC has not been thoroughly investigated.

Aim: To identify N7-methylguanosine (m7G) related prognostic biomarkers in HCC. Furthermore, we also studied the association of m7G–related prognostic gene signature with immune infiltration in HCC.

Methods: The TCGA datasets were used as a training and GEO dataset “GSE76427” for validation of the results. Statistical analyses were performed using the R statistical software version 4.1.2.

Results: Functional enrichment analysis identified some pathogenesis related to HCC. We identified 3 m7G-related genes (CDK1, ANO1, and PDGFRA) as prognostic biomarkers for HCC. A risk score was calculated from these 3 prognostic m7G-related genes which showed the high-risk group had a significantly poorer prognosis than the low-risk group in both training and validation datasets. The 3- and 5-years overall survival was predicted better with the risk score than the ideal model in the entire cohort in the predictive nomogram. Furthermore, immune checkpoint genes like CTLA4, HAVCR2, LAG3, and TIGT were expressed significantly higher in the high-risk group and the chemotherapy sensitivity analysis showed that the high-risk groups were responsive to sorafenib treatment.

Conclusion: These 3 m7G genes related signature model can be used as prognostic biomarkers in HCC and a guide for immunotherapy and chemotherapy response. Future clinical study on this biomarker model is required to verify its clinical implications.

Comparison of clinicopathological traits and prognostic factors of hepatocellular carcinoma with and without cirrhotic background

The difference of the patients bearing hepatocellular carcinoma (HCC) with and without cirrhosis at clinical level has not been completely determined. This study compared their differences in clinicopathological traits and prognostic factors for relapse-free survival (RFS) and overall survival (OS). Animal model was established to validate the result of clinical observation. As a result, 82 patients bearing HCC with no cirrhosis (HCC-NC) and 146 patients bearing HCC with cirrhosis (HCC-C) were included. HCC-NC exhibited shorter prothrombin time and higher plasma albumin than HCC-C. In HCC-NC, satellite nodule was an independent risk factor for OS, and high γ-glutamyl transpeptidase was an independent risk factor for RFS. In HCC-C, female sex was an independent risk factor for OS. Stratified analysis showed the OS and RFS of HCC-NC were better than HCC-C in conditions like without cancer embolus (in the portal vein or bile duct), without lymphadenopathy in hepatic portal, without satellite nodule and with small or high-differentiated tumor. Animal model analysis showed HCC-NC had a higher liver/body weight ratio, less tumor count and smaller max tumor volume than HCC-C. In conclusion, clinicopathological traits and risk factors influencing postoperative OS and RFS differed between patients with HCC-C and HCC-NC.

Immunobiology and immunotherapy of HCC: spotlight on innate and innate-like immune cells

Immune-based therapies such as immune checkpoint inhibitors have revolutionized the systemic treatment of various cancer types. The therapeutic application of monoclonal antibodies targeting inhibitory pathways such as programmed cell death-1(PD-1)/programmed cell death ligand 1 (PD-L1) and CTLA-4 to cells of the adaptive immune system has recently been shown to generate meaningful improvement in the clinical outcome of hepatocellular carcinoma (HCC). Nevertheless, current immunotherapeutic approaches induce durable responses in only a subset of HCC patients. Since immunologic mechanisms such as chronic inflammation due to chronic viral hepatitis or alcoholic and nonalcoholic fatty liver disease play a crucial role in the initiation, development, and progression of HCC, it is important to understand the underlying mechanisms shaping the unique tumor microenvironment of liver cancer. The liver is an immunologic organ with large populations of innate and innate-like immune cells and is exposed to bacterial, viral, and fungal antigens through the gut-liver axis. Here, we summarize and highlight the role of these cells in liver cancer and propose strategies to therapeutically target them. We also discuss current immunotherapeutic strategies in HCC and outline recent advances in our understanding of how the therapeutic potential of these agents might be enhanced.

Immune-related genes have prognostic significance in head and neck squamous cell carcinoma

AIMS

Head and neck squamous cell carcinoma (HNSCC) is an highly aggressive tumor with heterogeneous prognosis. We here report that immune-related genes (IRGs) could effectively distinguish prognostically different HNSCC patients.

MATERIALS AND METHODS

MRNA levels of 1333 IRGs that from ImmPort database in HNSCC samples were acquired from the Cancer Genome Atlas (TCGA). H2o, a machine learning-based R package, was used for screening the top most representative genes from the IRGs. Univariate Cox-regression analysis was performed to identify prognostically-related genes based on the randomly generated training samples from TCGA set. LASSO Cox-regression analysis was applied for the construction of prognostic model for HNSCC. A total of six IRGs were finally retained for their prognostic significance and used for LASSO Cox-regression analysis.

KEY FINDINGS

Samples from exclusive training and testing set that randomly generated from TCGA, and another independent validation set from the Gene Expression Omnibus (GEO) were divided into high- and low-risk groups according to the prognostic model. HNSCC samples within high-risk groups have significantly inferior overall survival (OS) compared with those within low-risk groups. Differences in genomic mutation landscape and tumor infiltration immune cells also exist between the two sample groups. What's more, risk score was proved to be an independent prognostic factor for HNSCC by stratification analysis.

SIGNIFICANCE

IRGs are pivotal HNSCC prognostic signatures and should be helpful for its clinical decision-making.

New landscapes and horizons in hepatocellular carcinoma therapy

Hepatocellular carcinoma (HCC), is the sixth most frequent form of cancer and leads to the fourth highest number of deaths each year. HCC results from a combination of environmental factors and aging as there are driver mutations at oncogenes which occur during aging. Most of HCCs are diagnosed at advanced stage preventing curative therapies. Treatment in advanced stage is a challenging and pressing problem, and novel and well-tolerated therapies are urgently needed. We will discuss further advances beyond sorafenib that target additional signaling pathways and immune checkpoint proteins. The scenario of possible systemic therapies for patients with advanced HCC has changed dramatically in recent years. Personalized genomics and various other omics approaches may identify actionable biochemical targets, which are activated in individual patients, which may enhance therapeutic outcomes. Further studies are needed to identify predictive biomarkers and aberrantly activated signaling pathways capable of guiding the clinician in choosing the most appropriate therapy for the individual patient.

Mean platelet volume predicts survival in patients with hepatocellular carcinoma and type 2 diabetes

BACKGROUND

Patients with hepatocellular carcinoma (HCC) having pre-existing type 2 diabetes (T2DM) have a poorer prognosis than those without T2DM. Moreover, accumulating evidence reveals that activated platelets play a crucial role in tumor and T2DM. The mean platelet volume (MPV) indicates platelet activation and is altered in malignancies. The present study aimed to investigate the clinical significance of MPV in patients with HCC having T2DM.

METHODS

This retrospective study performed between January 2010 and December 2013 included 331 patients with HCC (165 with T2DM and 166 without T2DM). The overall survival was compared, and the predictors of overall survival were analyzed.

RESULTS

The patients with T2DM had lower MPV levels than those without T2DM. Furthermore, the MPV levels significantly differentiated T2DM from non-T2DM. In addition, for patients with T2DM, the overall survival was significantly shorter in patients with low MPV levels than in those with high MPV levels. Multivariate analysis identified decreased MPV as an independent prognostic factor for overall survival only in patients with T2DM, but not in those without T2DM.

CONCLUSION

Reduced MPV was a prognostic factor for poor outcome in patients with HCC and T2DM.

Dynamics of Axl Receptor Shedding in Hepatocellular Carcinoma and Its Implication for Theranostics

Signaling of the receptor tyrosine kinase Axl and its ligand Gas6 is crucially involved in the development of liver fibrosis and hepatocellular carcinoma (HCC) by activation of hepatic stellate cells and modulation of hepatocyte differentiation. Shedding of Axl’s ectodomain leads to the release of soluble Axl (sAxl), which is increased in advanced fibrosis and in early-to-late stage HCC in the presence and absence of cirrhosis. Here, we focus on the dynamics of Axl receptor shedding and delineate possible scenarios how Axl signaling might act as driver of fibrosis progression and HCC development. Based on experimental and clinical data, we discuss the consequences of modifying Axl signaling by sAxl cleavage, as well as cellular strategies to escape from antagonizing effects of Axl shedding by the involvement of the hepatic microenvironment. We emphasize a correlation between free Gas6 and free sAxl levels favoring abundant Gas6/Axl signaling in advanced fibrosis and HCC. The raised scenario provides a solid basis for theranostics allowing the use of sAxl as an accurate diagnostic biomarker of liver cirrhosis and HCC, as well as Axl receptor signaling for therapeutic intervention in stratified HCC patients.

Selective deletion of hepatocyte platelet-derived growth factor receptor α and development of liver fibrosis in mice

BACKGROUND

Platelet-derived growth factor receptor α (PDGFRα) expression is increased in activated hepatic stellate cells (HSCs) in cirrhotic liver, while normal hepatocytes express PDGFRα at a negligible level. However, cancerous hepatocytes may show upregulation of PDGFRα, and hepatocellular carcinoma is preceded by chronic liver injury. The role of PDGFRα in non-cancerous hepatocytes and liver fibrosis is unclear. We hypothesized that upon liver injury, PDGFRα in insulted hepatocytes contributes to liver fibrosis by facilitating intercellular crosstalk between hepatocytes and HSCs.

METHODS

Hepatocytes were isolated from normal and thioacetamide (TAA)-induced cirrhotic livers for assessment of PDGFRα expression. Conditional knock-out (KO) C57BL/6 mice, in which PDGFRα was selectively deleted in hepatocytes, were generated. Liver fibrosis was induced by injecting TAA for 8 weeks. Hep3B cells were transfected with a small interfering RNA (siRNA) (PDGFRα or control) and co-cultured with LX2 cells.

RESULTS

PDGFRα expression was increased in hepatocytes from fibrotic livers compared to normal livers. Conditional PDGFRα KO mice had attenuated TAA-induced liver fibrosis with decreased HSC activation and proliferation. Immunoblot analyses revealed decreased expression of phospho-p44/42 MAPK in TAA-treated KO mice; these mice also showed almost complete suppression of the upregulation of mouse double minute 2. Although KO mice exhibited increased expression of transforming growth factor (TGF)-β and Smad2/3, this was compensated for by increased expression of inhibitory Smad7. LX2 cells co-cultured with PDGFRα siRNA-infected Hep3B cells showed decreased PDGFRα, α smooth muscle actin, collagen α1(I), TGFβ, and Smad2/3 expression. LX2/PDGFRα-deleted hepatocyte co-culture medium showed decreased PDGF-BB and PDGF-CC levels.

CONCLUSIONS

Deletion of PDGFRα in hepatocytes attenuated the upregulation of PDGFRα in HSCs after TAA treatment, resulting in decreased liver fibrosis and HSC activation. This suggests that in the event of chronic liver injury, PDGFRα in hepatocytes plays an important role in liver fibrosis by affecting PDGFRα expression in HSCs.

Platelet-derived growth factor receptor alpha (PDGFRα) is overexpressed in NK/T-cell lymphoma and mediates cell survival

Nasal-type natural killer/T-cell lymphoma (NKTCL) is a subtype of non-Hodgkin lymphoma (NHL) that is clinically aggressive and has a poor prognosis. Platelet-derived growth factor receptors (PDGFRs) and their ligands (PDGFs) play important roles in angiogenesis, cancer cell proliferation, survival, migration and poor prognosis in various tumours. However, the significance of PDGFRs in NKTCL remains unknown. Herein, the present study aimed to investigate the important role of PDGFRα in pathogenesis, progression and prognisis of NKTCL. Firstly, we performed immunohistochemical staining, qRT-PCR and western blotting to determine PDGFRα expression in formalin-fixed, paraffin-embedded tissue sections from 78 NKTCL cases and in cell lines. Secondly, correlations between PDGFRα expression and NKTCL clinical parameters and prognosis were analysed. Moreover, a biological assessment of PDGFRα blockade in two NKTCL cell lines was conducted through proliferation assay, cell-cycle evaluation and apoptosis detection by flow cytometry analyses. Furthermore, we detected in vivo activity of imatinib in mouse model of NKTCL. We found that the expression of PDGFRα was significantly higher in NKTCL tissues compared to the reactive lymphoid hyperplasia of the nasopharynx (P = 0.028). High PDGFRα expression was strongly associated with a high LDH level (P = 0.028) and III-IV stage (P = 0.013). NKTCL patients with high PDGFRα expression displayed a reduced median overall survival time and progression-free survival time when compared with those with low PDGFRα expression (P = 0.011, P = 0.005, respectively). Cox multivariate analysis showed that III-IV stage (P = 0.024) and high PDGFRα expression (P = 0.003) were independent prognostic factors in NKTCL patients. Biological assessment assays in two NKTCL cell lines revealed that a specific PDGFR antagonist, imatinib, inhibited cell viability, blocked cell cycle progression at G0/G1 stage and induced apoptosis. Similarly, the in vivo assay showed that imatinib delayed mouse model tumour growth. In conclusion, NKTCL tumour cells have prominent PDGFRα expression, which can serve as a candidate prognostic marker. PDGFR antagonists have significant biological effect on NKTCL and may be useful therapeutic agents for treatment of NKTCL.

Novel 2-phenyloxypyrimidine derivative induces apoptosis and autophagy via inhibiting PI3K pathway and activating MAPK/ERK signaling in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related mortality globally. Because most patients are diagnosed at advanced stages of the disease, multi-targeted tyrosine kinase inhibitor sorafenib is the only available drug to show limited effectiveness. Novel and effective therapies are unmet medical need for advanced HCC patients. Given that the aberrant expression and activity of platelet-derived growth factor receptor α (PDGFRα) are closely associated with the pathogenesis of HCC, here we present the discovery and identification of a novel PDGFRα inhibitor, N-(3-((4-(benzofuran-2-yl)pyrimidin-2-yl)oxy)-4-methylphenyl)-4-((4-methylpiperazin-1-yl)methyl)benzamide (E5) after comparison of different derivatives. We found that E5 inhibited proliferation and induced apoptosis in HCC cells. Since the pan-caspase inhibitor Z-VAD-FMK partially rescued HCC cells from E5-reduced cell viability, autophagic cell death triggered by E5 was subsequently investigated. E5 could induce the conversion of LC3-I to LC3-II, increase the expression of Atg5 and restore the autophagy flux blocked by chloroquine. Meanwhile, E5 was able to downregulate the PDGFRα/PI3K/AKT/mTOR pathway and to activate MAPK/ERK signaling pathway. Taken together, in addition to the possibility of E5 as a valuable drug candidate, the present study further supports the notion that targeted inhibition of PDGFRα is a promising therapeutic strategy for HCC.

Serum amyloid a induces M2b-like macrophage polarization during liver inflammation

Hepatitis causes hepatic cell injury, regeneration and different levels of fibrogenesis, and severe liver fibrogenesis progresses into cirrhosis with liver dysfunction. Serum amyloid A (SAA) is an acute phase protein that is predominantly secreted by hepatocytes during early injury or infection. Nevertheless, the relationship of SAA and development of cirrhosis as well as the underlying molecular mechanisms is largely unknown. Here, we found that macrophages are the major SAA-binding cells in the injured liver. in vitro, macrophages treated with SAA exhibited high production of IL-10 but low production of IL-12, as features for M2 macrophages. Moreover, these polarized M2 macrophages by SAA also produced IL-1, IL-6 and TNFa, characteristics for an M2b subtype, rather than an alternative M2a or fibrogenic M2c subtype. In a mouse model of carbon tetrachloride (CCl4)-induced hepatic fibrogenesis/cirrhosis, anti-SAA sera were used to block the effects of SAA, resulting in increases in the severity of hepatic fibrosis, suggesting an overall anti-fibrogenic effect of SAA. Isolated macrophages from mouse liver showed that anti-SAA appeared to alter the polarization of macrophages from M2b to M2c, suggesting that SAA may induce M2b-like macrophage polarization during liver inflammation, which prevents the liver from fibrogenesis.