Peroxisome proliferator-activated receptor gamma as a therapeutic target for hepatocellular carcinoma: Experimental and clinical scenarios

Nano-revolution in hepatocellular carcinoma: A multidisciplinary odyssey - Are we there yet?

In this editorial we comment on the review by Zhou et al reviewing the landscape of nanomedicine in the treatment of hepatocellular carcinoma (HCC). We focus on the immense potential of nanotechnology, particularly ligand-receptor mediated nanotherapy, in revolutionizing the treatment landscape of HCC. Despite advancements in multidisciplinary treatment, HCC remains a significant global health challenge. Ligand-mediated nanotherapy offers the opportunity for precise drug delivery to tumor sites, targeting specific receptors overexpressed in HCC cells, thereby enhancing efficacy and minimizing side effects. Overcoming drug resistance and aggressive tumor biology is facilitated by nanomedicine, bypassing traditional hurdles encountered in chemotherapy. Examples include targeting glypican-3, asialoglycoprotein, transferrin receptor or folic acid receptors, capitalizing on their over-expression in tumor cells. The ability for multi-receptor targeting through dual-ligand nanoparticle modification holds the prospect of further enhancement in specificity and efficacy of directed therapy. However, challenges including immune responses, reproducibility in nanoparticle synthesis, and production scalability remain. Future directions involve refining targeting strategies, improving drug release mechanisms, and streamlining production processes to enable personalized and multifunctional nanotherapies. Overall, the integration of nanotherapy in HCC treatment holds immense promise, but continued partnership and effort are needed in offering hope for more effective, precise, and accessible clinical care in the management of HCC.

Human Papilloma Virus Positive Oropharyngeal Squamous Cell Carcinoma and the Immune System: Pathogenesis, Immunotherapy and Future Perspectives

Oropharyngeal squamous cell carcinoma (OPSCC), a subset of head and neck squamous cell carcinoma (HNSCC), involves the palatine tonsils, soft palate, base of tongue, and uvula, with the ability to spread to adjacent subsites. Personalized treatment strategies for Human Papillomavirus-associated squamous cell carcinoma of the oropharynx (HPV+OPSCC) are yet to be established. In this article, we summarise our current understanding of the pathogenesis of HPV+OPSCC, the intrinsic role of the immune system, current ICI clinical trials, and the potential role of small molecule immunotherapy in HPV+OPSCC.

Correlation of endoplasmic reticulum stress patterns with the immune microenvironment in hepatocellular carcinoma: a prognostic signature analysis

Backgrounds

The extended duration of endoplasmic reticulum stress (ERS) can impact the progression of hepatocellular carcinoma (HCC) and the efficacy of immunotherapies by interacting with immune cells that have infiltrated the tumor microenvironment (TME).

Methods and results

The study utilized a training cohort of 364 HCC patients with complete information from The Cancer Genome Atlas Program (TCGA) database, and a validation cohort of 231 HCC patients from the International Cancer Genome Consortium (ICGC) database. The genes related to ERS exhibiting a strong correlation with overall survival (OS) were identified using univariate Cox regression analysis. A 13-gene predictive signature was then produced through the least absolute shrinkage and selection operator (LASSO) regression approach. The data revealed that the ERS-associated gene signature effectively stratified patients into high- or low-risk groups regarding OS in both the training and validation cohorts (P < 0.0001 and P = 0.00029, respectively). Using the multivariate method, it is still an independent prognostic factor in both the training and validation cohorts (P < 0.001 and P = 0.008, respectively). Moreover, several metabolic pathways were identified to be enriched among the 13 genes in the predictive signature. When the ERS-associated gene signature was combined with the tumor-node-metastasis (TNM) stage, the ERS nomogram performed better than either the gene signature or the TNM stage alone (C-index values: 0.731, 0.729, and 0.573, respectively). Further analysis revealed that patients in the high-risk group exhibited increased infiltration of immune cells. Additionally, GP6 was downregulated in HCC tissues among these signature genes (P < 0.05), which was related to poor OS.

Conclusions

The data suggest that this novel ERS-associated gene signature could contribute to personalized cancer management for HCC. Moreover, targeting GP6 inhibition might be a potential method for HCC therapy.

Ionizing radiation promotes, whereas calorie restriction suppresses, NASH and hepatocellular carcinoma in mice

The pathological conditions of nonalcoholic fatty liver disease and nonalcoholic steatohepatitis (NASH) are the major risk factors for hepatocellular carcinoma (HCC). Exposure to DNA-damaging agents such as ionizing radiation is another risk factor for HCC; calorie restriction (CR), however, effectively delays the onset of radiation-induced HCC. We investigated whether NASH is relevant to radiation-induced HCC and the cancer-preventing effect of CR. Eight-day-old male B6C3F1 mice were irradiated with 3.8 Gy of X-rays and then fed a standard diet or 30% CR diet from 49 days of age until necropsy, which was performed from 56 to 600 days with ~100-day intervals to assess both pathological changes and gene expression levels. We found that early-life exposure to radiation accelerated lipid accumulation and NASH-like histopathological changes in the liver, accompanied by accelerated development of HCC. CR ameliorated the changes in lipid metabolism in the liver and reversed the NASH-like pathology, which effectively delayed HCC development. Gene-expression profiling revealed the radiation-related activation and CR-related suppression of the peroxisome proliferator-activated receptor gamma/Cd36 pathway of transmembrane fatty-acid translocation before development of the NASH-like state. Thus, early-life exposure to radiation affects lipid metabolism and induces a steatoinflammatory microenvironment that favors HCC development. Therefore, targeting this pathway by CR (or measures that mimic CR) may be a promising strategy for preventing HCC caused by either radiation or other DNA-damaging agents.

Coagulation Dysfunctions in Non-Alcoholic Fatty Liver Disease-Oxidative Stress and Inflammation Relevance

Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver diseases. Its incidence is progressively rising and it is possibly becoming a worldwide epidemic. NAFLD encompasses a spectrum of diseases accounting for the chronic accumulation of fat within the hepatocytes due to various causes, excluding excessive alcohol consumption. In this study, we aimed to focus on finding evidence regarding the implications of oxidative stress and inflammatory processes that form the multifaceted pathophysiological tableau in relation to thrombotic events that co-occur in NAFLD and associated chronic liver diseases. Recent evidence on the pathophysiology of NAFLD suggests that a complex pattern of multidirectional components, such as prooxidative, proinflammatory, and prothrombotic components, better explains the multiple factors that promote the mechanisms underlying the fatty acid excess and subsequent processes. As there is extensive evidence on the multi-component nature of NAFLD pathophysiology, further studies could address the complex interactions that underlie the development and progression of the disease. Therefore, this study aimed to describe possible pathophysiological mechanisms connecting the molecular impairments with the various clinical manifestations, focusing especially on the interactions among oxidative stress, inflammation, and coagulation dysfunctions. Thus, we described the possible bidirectional modulation among coagulation homeostasis, oxidative stress, and inflammation that occurs in the various stages of NAFLD.

Non-alcoholic fatty liver disease and diabetes mellitus as growing aetiologies of hepatocellular carcinoma

Obesity-related complications such as non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes (T2D) are well-established risk factors for the development of hepatocellular carcinoma (HCC). This review provides insights into the molecular mechanisms that underlie the role of steatosis, hyperinsulinemia and hepatic inflammation in HCC development and progression. We focus on recent findings linking intracellular pathways and transcription factors that can trigger the reprogramming of hepatic cells. In addition, we highlight the role of enzymes in dysregulated metabolic activity and consequent dysfunctional signalling. Finally, we discuss the potential uses and challenges of novel therapeutic strategies to prevent and treat NAFLD/T2D-associated HCC.

Shikonin Binds and Represses PPARγ Activity by Releasing Coactivators and Modulating Histone Methylation Codes

Shikonin, a natural ingredient produced by Lithospermum erythrorhizon, has anti-inflammatory, anti-cancer, and anti-obesity effects. It also inhibits adipocyte differentiation; however, the underlying molecular and epigenetic mechanisms remain unclear. We performed RNA-sequencing of shikonin-treated 3T3-L1 cells. Gene ontology and gene set enrichment analysis showed that shikonin is significantly associated with genes related to adipogenesis, histone modification, and PPARγ. Shikonin treatment downregulated the mRNA expression of PPARγ-responsive genes and rosiglitazone-induced transcriptional activity of PPARγ. Microscale thermophoresis assays showed a KD value 1.4 ± 0.13 μM for binding between shikonin and PPARγ. Glutathione S-transferase pull-down assays exhibited that shikonin blocked the rosiglitazone-dependent association of PPARγ with its coactivator CBP. In addition, shikonin decreased the enrichment of the active histone code H3K4me3 and increased the repressive code H3K27me3 of PPARγ target promoters. Shikonin is a PPARγ antagonist that suppresses adipogenesis by regulating the enrichment of histone codes during adipogenesis. Therefore, it may be used to treat obesity-related disorders via epigenetic changes.

PPARs and the Kynurenine Pathway in Melanoma-Potential Biological Interactions

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors involved in various physiological and pathological processes within the skin. PPARs regulate several processes in one of the most aggressive skin cancers, melanoma, including proliferation, cell cycle, metabolic homeostasis, cell death, and metastasis. In this review, we focused not only on the biological activity of PPAR isoforms in melanoma initiation, progression, and metastasis but also on potential biological interactions between the PPAR signaling and the kynurenine pathways. The kynurenine pathway is a major pathway of tryptophan metabolism leading to nicotinamide adenine dinucleotide (NAD+) production. Importantly, various tryptophan metabolites exert biological activity toward cancer cells, including melanoma. Previous studies confirmed the functional relationship between PPAR and the kynurenine pathway in skeletal muscles. Despite the fact this interaction has not been reported in melanoma to date, some bioinformatics data and biological activity of PPAR ligands and tryptophan metabolites may suggest a potential involvement of these metabolic and signaling pathways in melanoma initiation, progression, and metastasis. Importantly, the possible relationship between the PPAR signaling pathway and the kynurenine pathway may relate not only to the direct biological effect on melanoma cells but also to the tumor microenvironment and the immune system.

Nuclear Receptor Imaging In Vivo-Clinical and Research Advances

Nuclear receptors are transcription factors that function in normal physiology and play important roles in diseases such as cancer, inflammation, and diabetes. Noninvasive imaging of nuclear receptors can be achieved using radiolabeled ligands and positron emission tomography (PET). This quantitative imaging approach can be viewed as an in vivo equivalent of the classic radioligand binding assay. A main clinical application of nuclear receptor imaging in oncology is to identify metastatic sites expressing nuclear receptors that are targets for approved drug therapies and are capable of binding ligands to improve treatment decision-making. Research applications of nuclear receptor imaging include novel synthetic ligand and drug development by quantifying target drug engagement with the receptor for optimal therapeutic drug dosing and for fundamental research into nuclear receptor function in cells and animal models. This mini-review provides an overview of PET imaging of nuclear receptors with a focus on radioligands for estrogen receptor, progesterone receptor, and androgen receptor and their use in breast and prostate cancer.

Identification of ZBTB9 as a potential therapeutic target against dysregulation of tumor cells proliferation and a novel biomarker in Liver Hepatocellular Carcinoma

BACKGROUND

Zinc finger and bric-a-brac/tramtrack/broad (ZBTB) domain-containing proteins have been reported to be associated with many tumors' development. However, in tumor initiation and progression, the role of ZBTB9, one of the protein family, and its prognostic value were yet to be elucidated in Liver Hepatocellular Carcinoma (LIHC).

METHODS

We used R software and online bioinformatics analysis tools such as GEPIA2, cBioPortal, TIMER2, Metascape, UALCAN, STRING, TISIDB, and COSMIC to investigate ZBTB9's characteristics and function in LIHC, including abnormal expression, carcinogenic role, related signaling pathways and prognostic value. Furthermore, cell experiments (such as formation, wound healing, and transwell assays) and analyses based on clinical samples (such as immunohistochemistry (IHC) and promoter methylation analysis) were conducted to verify pivotal conclusions.

RESULTS

ZBTB9 was overexpressed in LIHC samples compared to adjacent normal tissues. Through the analysis of genomic alteration and promoter hypomethylation, the clinical value and etiology of abnormal expression of ZBTB9 were preliminarily exlpored. Subsequent evidence showed that it could result in tumor progression and poor prognosis via activating cell cycle, DNA repair, MYC, and KRAS-associated signaling pathways as well as rendering immune dysregulation. After the knockdown of ZBTB9, evidently inhibited capacities of tumor cells proliferation and migration were observed. These results together indicated that ZBTB9 could be a promising prognostic biomarker and had the potential value to offer novel therapeutic targets for LIHC treatment.

CONCLUSIONS

ZBTB9 was identified as a novel biomarker to predict the prognosis and tumor progression in LIHC, and a promising therapeutic target to invert tumor development.

Peroxisome proliferator-activated receptor gamma and its natural agonists in the treatment of kidney diseases

Kidney disease is one of the leading non-communicable diseases related to tremendous health and economic burden globally. Diabetes, hypertension, obesity and cardiovascular conditions are the major risk factors for kidney disease, followed by infections, toxicity and autoimmune causes. The peroxisome proliferator-activated receptor gamma (PPAR-γ) is a ligand-activated nuclear receptor that plays an essential role in kidney physiology and disease. The synthetic agonists of PPAR-γ shows a therapeutic effect in various kidney conditions; however, the associated side effect restricts their use. Therefore, there is an increasing interest in exploring natural products with PPARγ-activating potential, which can be a promising solution to developing effective and safe treatment of kidney diseases. In this review, we have discussed the role of PPAR-γ in the pathophysiology of kidney disease and the potential of natural PPAR-γ agonists in treating various kidney diseases, including acute kidney injury, diabetic kidney disease, obesity-induced nephropathy, hypertension nephropathy and IgA nephropathy. PPAR-γ is a potential target for the natural PPAR-γ agonists against kidney disease; however, more studies are required in this direction.