Crithmum maritimum Extract Restores Lipid Homeostasis and Metabolic Profile of Liver Cancer Cells to a Normal Phenotype.

Hepatocellular carcinoma (HCC) is an alarming epidemiological clinical problem worldwide. Pharmacological approaches currently available do not provide adequate responses due to poor effectiveness, high toxicity, and serious side effects. Our previous studies have shown that the wild edible plant Crithmum maritimum L. inhibits the growth of liver cancer cells and promotes liver cell differentiation by reducing lactic acid fermentation (Warburg effect). Here, we aimed to further characterise the effects of C. maritimum on lipid metabolism and markers of cellular metabolic health, such as AMP-activated protein kinase (AMPK), Sirtuin 1 (SIRT1), and Sirtuin 3 (SIRT3), as well as the insulin signalling pathway. To better mimic the biological spectrum of HCC, we employed four HCC cell lines with different degrees of tumorigenicity and lactic acid fermentation/Warburg phenotype. Lipid accumulation was assessed by Oil Red O (ORO) staining, while gene expression was measured by real-time quantitative PCR (RT-qPCR). The activation of AMPK and insulin signalling pathways was determined by Western blotting. Results indicate that C. maritimum prevents lipid accumulation, downregulates lipid and cholesterol biosynthesis, and modulates markers of metabolic health, such as AMPK, SIRT1 and SIRT3. This modulation is different amongst HCC cell lines, revealing an important functional versatility of C. maritimum. Taken together, our findings corroborate the importance of C. maritimum as a valuable nutraceutical, reinforcing its role for the improvement of metabolic health.

Microenvironmental stress drives tumor cell maladaptation and malignancy through regulation of mitochondrial and nuclear cytochrome c oxidase subunits.

After decades of focus on molecular genetics in cancer research, the role of metabolic and environmental factors is being reassessed. Here, we investigated the role of microenvironment in the promotion of malignant behavior in tumor cells with a different reliance on oxidative phosphorylation (OXPHOS) versus lactic acid fermentation/Warburg effect. To this end, we evaluated the effects of microenvironmental challenges (hypoxia, acidity, and high glucose) on the expression of mitochondrial-encoded cytochrome c oxidase 1 (COX I) and two nuclear-encoded isoforms 4 (COX IV-1 and COX IV-2). We have shown that tumor cells with an "OXPHOS phenotype" respond to hypoxia by upregulating COX IV-1, whereas cells that rely on lactic acid fermentation maximized COX IV-2 expression. Acidity upregulates COX IV-2 regardless of the metabolic state of the cell, whereas high glucose stimulates the expression of COX I and COX IV-1, with a stronger effect in fermenting cells. Our results uncover that "energy phenotype" of tumor cells drives their adaptive response to microenvironment stress.NEW & NOTEWORTHY How microenvironmental stress (hypoxia, acidity, and high glucose) supports tumor growth has not yet been fully elucidated. Here, we demonstrated that these stressors promote malignancy by controlling the expression of cytochrome c oxidase I (COX I), and COX IV-1 and COX IV-2 based on the "energy phenotype" of cancer cells (OXPHOS vs. fermentation). Our results uncover a novel process by which the "energy phenotype" of cancer cells drives the adaptive response to microenvironment stress.

Inhibition of lysophosphatidic acid receptor 6 upregulated by the choline-deficient l-amino acid-defined diet prevents hepatocarcinogenesis in mice.

Hepatocellular carcinoma (HCC) is one of the most worrying tumors worldwide today, and its epidemiology is on the rise. Traditional pharmacological approaches have shown unfavorable results and exhibited many side effects. Hence, there is a need for new efficacious molecules with fewer side effects and improvements on traditional approaches. We previously showed that lysophosphatidic acid (LPA) supports hepatocarcinogenesis, and its effects are mainly mediated by LPA receptor 6 (LPAR6). We also reported that 9-xanthylacetic acid (XAA) acts as an antagonist of LPAR6 to inhibit the growth of HCC. Here, we report that LPAR6 is involved in the choline-deficient l-amino acid-defined (CDAA) diet-induced hepatocarcinogenesis in mice. Our data demonstrate that CDAA diet-induced metabolic imbalance stimulates LPAR6 expression in mice and that XAA counteracts diet-induced effects on hepatic lipid accumulation, fibrosis, inflammation, and HCC development. These conclusions are corroborated by results on LPAR6 gain and loss-of-function in HCC cells.

Metabolism as a New Avenue for Hepatocellular Carcinoma Therapy.

Hepatocellular carcinoma is today the sixth leading cause of cancer-related death worldwide, despite the decreased incidence of chronic hepatitis infections. This is due to the increased diffusion of metabolic diseases such as the metabolic syndrome, diabetes, obesity, and nonalcoholic steatohepatitis (NASH). The current protein kinase inhibitor therapies in HCC are very aggressive and not curative. From this perspective, a shift in strategy toward metabolic therapies may represent a promising option. Here, we review current knowledge on metabolic dysregulation in HCC and therapeutic approaches targeting metabolic pathways. We also propose a multi-target metabolic approach as a possible new option in HCC pharmacology.

Crithmum maritimum Improves Sorafenib Sensitivity by Decreasing Lactic Acid Fermentation and Inducing a Pro-Hepatocyte Marker Profile in Hepatocellular Carcinoma.

Edible plants are gaining importance as an integrative therapy for many chronic diseases, including cancer. We first reported that the edible wild plant Crithmum maritimum L. inhibits the growth of hepatocellular carcinoma (HCC) cells by exerting a multitarget action on cellular metabolism and bioenergetic profile. Here, we show that Crithmum maritimum ethyl acetate extract significantly increases the responsiveness of HCC cells to the chemotherapeutic drug sorafenib by reducing lactic acid fermentation and inducing a pro-hepatocyte biomarker profile. Our findings strengthen the role of Crithmum maritimum L. as a valuable nutraceutical tool to support pharmacological therapeutic interventions in HCC.

The Edible Plant Crithmum maritimum Shows Nutraceutical Properties by Targeting Energy Metabolism in Hepatic Cancer.

In the past few years, evidence has supported the role of plants as a valuable tool for the development of promising therapeutic support options for many diseases, including cancer. We recently discovered that the edible wild plant Crithmum maritimum L. effectively inhibits the growth of hepatocellular carcinoma (HCC) cells and we provide insights into the biological mechanisms involved. Here, we aimed to characterize the effect of ethyl acetate extract of Crithmum maritimum on the bioenergetic phenotype of HCC cells and if this is associated with the anti-tumour effect we previously described. Results show that Crithmum maritimum significantly increases cellular respiration and reduces lactic fermentation in HCC cells, and that this reduction of the fermentative glycolytic phenotype is linked to inhibition of HCC growth. These data provide new preclinical evidence supporting the role of Crithmum maritimum L. as a nutraceutical option to expand the therapeutic opportunities in the management of HCC.

A distinctive protein signature induced by lysophosphatidic acid receptor 6 (LPAR6) expression in hepatocellular carcinoma cells.

Hepatocellular carcinoma (HCC) is the most commonly diagnosed liver malignancy, ranking third in the overall global cancer-related mortality. A complex network of interacting proteins controls HCC growth and progression. Lysophosphatidic acid receptors (LPAR) are commonly overexpressed in HCC. In particular, we have previously reported that the expression of LPAR6 sustains tumorigenesis and growth of HCC and results in a poor prognosis in HCC patients. Here, we applied a comparative proteomic approach to compare protein expression in both LPAR6 expressing (HLE-LPAR6) and nonexpressing HCC cells (HLE-neo). We found changes in the expression levels of 19 proteins, which include carbohydrate metabolism enzymes, redox and detoxification enzymes, and gene-expression regulatory proteins. Our findings support the role of LPAR6 in controlling the expression of a distinctive protein signature in HCC cells, which can offer a valuable resource for the identification of potential theranostic biomarkers.

Inhibition of Hepatocellular Carcinoma Growth by Ethyl Acetate Extracts of Apulian Brassica oleracea L. and Crithmum maritimum L.

Nowadays, a growing body of evidence supports the view that plants offer an extraordinary opportunity to discover and develop new promising therapeutic strategies for many diseases, including cancer. Here we tested the anticancer action against Hepatocellular carcinoma (HCC) of extracts obtained from two plants harvested in Apulia, namely Brassica oleracea L. and Crithmum maritimum L. B. oleracea was grown in biodynamical agriculture without any agrochemical input, instead C. maritimum was collected on Apulian coasts and is still commonly eaten in Apulia. HCC, one of the most frequent tumors worldwide, is estimated to become the third leading cause of cancer-related deaths in Western Countries by 2030. The approved synthetic drugs for the treatment of HCC are currently inadequate in terms of therapeutic results and tolerability. Hence, aim of the present study was to test the anticancer action against HCC of extracts obtained from Brassica oleracea L. and Crithmum maritimum L. We preliminary prepared extracts from both plants using four solvents with different polarity: hexane, ethyl acetate, methanol and ethanol. Then, we tested the effect of the different fractions in inhibiting HCC cell growth. Finally, we characterized the mechanism of action of the most effective fraction. We found that ethyl acetate fractions from both plants were the most effective in inhibiting HCC growth. In particular, we demonstrated that these fractions effectively reduce HCC growth by exerting, on one hand, a cytostatic effect through their action on the cell cycle, and on the other hand by triggering apoptosis and necrosis. Our findings support the notion that ethyl acetate fractions from Apulian B. oleracea and C. maritimum can be in perspective considered as promising tools to expand the opportunities to identify new and not toxic anticancer therapeutic approaches for HCC. Further pharmacological investigations will shed light on how this could be effectively achieved. Graphical Abstract Experimental workflow for the detection of the ethyl acetate extract of Brassica oleracea L. and Crithmum maritimum L. as an active fraction in inhibiting HCC cell growth.

Changes in gluconeogenesis and intracellular lipid accumulation characterize uremic human hepatocytes ex vivo.

It is well known that reduced glomerular filtration rate (GFR) leads to an increased risk of dyslipidemia, insulin resistance, and cardiovascular mortality. The liver is a central organ for metabolism, but its function in the uremic setting is still poorly characterized. We used human primary hepatocytes isolated from livers of nine donors with normal renal function to investigate perturbations in key metabolic pathways following exposure to uremic (n = 8) or healthy (n = 8) sera, and to serum-free control medium. Both uremic and healthy elicited consistent responses from hepatocytes from multiple donors and compared with serum-free control. However, at physiological insulin concentrations, uremic cells accumulated 56% more intracellular lipids. Also, when comparing uremic with healthy medium after culture, it contained more very-low-density lipoprotein-triglyceride and glucose. These changes were accompanied by decreased phosphorylation of AktS473 mRNA levels of key regulators of gluconeogenesis in uremic sera-treated hepatocytes such as phosphoenolpyruvate carboxykinase 1 and glucose 6-phosphate were elevated. We also found increased expression of 11ß-hydroxysteroid dehydrogenase mRNA in uremic cells, along with high phosphorylation of downstream p53 and phospholipase C-γ1Y783 Thus our ex vivo data suggest that the uremic hepatocytes rapidly develop a glycogenic and lipogenic condition accompanied by perturbations in a large number of signaling networks.

Lactic acid fermentation: A maladaptive mechanism and an evolutionary throwback boosting cancer drug resistance.

After four decades of research primarily focused on tumour genetics, the importance of metabolism in tumour biology is receiving renewed attention. Cancer cells undergo energy, biosynthetic and metabolic rewiring, which involves several pathways with a prevalent change from oxidative phosphorylation (OXPHOS) to lactic acid fermentation, known as the Warburg effect. During carcinogenesis, microenvironmental changes can trigger the transition from OXPHOS to lactic acid fermentation, an ancient form of energy supply, mimicking the behaviour of certain anaerobic unicellular organisms according to "atavistic" models of cancer. However, the role of this transition as a mechanism of cancer drug resistance is unclear. Here, we hypothesise that the metabolic rewiring of cancer cells to fermentation can be triggered, enhanced, and sustained by exposure to chronic or high-dose chemotherapy, thereby conferring resistance to drug therapy. We try to expand on the idea that metabolic reprogramming from OXPHOS to lactate fermentation in drug-resistant tumour cells occurs as a general phenotypic mechanism in any type of cancer, regardless of tumour cell heterogeneity, biodiversity, and genetic characteristics. This metabolic response may therefore represent a common feature in cancer biology that could be exploited for therapeutic purposes to overcome chemotherapy resistance, which is currently a major challenge in cancer treatment.

Cellular Adaptation Takes Advantage of Atavistic Regression Programs during Carcinogenesis.

Adaptation of cancer cells to extreme microenvironmental conditions (i.e., hypoxia, high acidity, and reduced nutrient availability) contributes to cancer resilience. Furthermore, neoplastic transformation can be envisioned as an extreme adaptive response to tissue damage or chronic injury. The recent Systemic-Evolutionary Theory of the Origin of Cancer (SETOC) hypothesizes that cancer cells "revert" to "primitive" characteristics either ontogenically (embryo-like) or phylogenetically (single-celled organisms). This regression may confer robustness and maintain the disordered state of the tissue, which is a hallmark of malignancy. Changes in cancer cell metabolism during adaptation may also be the consequence of altered microenvironmental conditions, often resulting in a shift toward lactic acid fermentation. However, the mechanisms underlying the robust adaptive capacity of cancer cells remain largely unknown. In recent years, cancer cells' metabolic flexibility has received increasing attention among researchers. Here, we focus on how changes in the microenvironment can affect cancer cell energy production and drug sensitivity. Indeed, changes in the cellular microenvironment may lead to a "shift" toward "atavistic" biologic features, such as the switch from oxidative phosphorylation (OXPHOS) to lactic acid fermentation, which can also sustain drug resistance. Finally, we point out new integrative metabolism-based pharmacological approaches and potential biomarkers for early detection.

Inhibition of LPAR6 overcomes sorafenib resistance by switching glycolysis into oxidative phosphorylation in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most threatening tumours in the world today. Pharmacological treatments for HCC mainly rely on protein kinase inhibitors, such as sorafenib and regorafenib. Even so, these approaches exhibit side effects and acquired drug resistance, which is an obstacle to HCC treatment. We have previously shown that selective lysophosphatidic acid receptor 6 (LPAR6) chemical antagonists inhibit HCC growth. Here, we investigated whether LPAR6 mediates resistance to sorafenib by affecting energy metabolism in HCC. To uncover the role of LPAR6 in drug resistance and cancer energy metabolism, we used a gain-of-function and loss-of-function approach in 2D tissue and 3D spheroids. LPAR6 was ectopically expressed in HLE cells (HLE-LPAR6) and knocked down in HepG2 (HepG2 LPAR6-shRNA). Measurements of oxygen consumption and lactate and pyruvate production were performed to assess the energy metabolism response of HCC cells to sorafenib treatment. We found that LPAR6 mediates the resistance of HCC cells to sorafenib by promoting lactic acid fermentation at the expense of oxidative phosphorylation (OXPHOS) and that the selective LPAR6 antagonist 9-xanthenyl acetate (XAA) can effectively overcome this resistance. Our study shows for the first time that an LPAR6-mediated metabolic mechanism supports sorafenib resistance in HCC and proposes a pharmacological approach to overcome it.

Role of inflammatory markers in the diagnosis of vascular contributions to cognitive impairment and dementia: a systematic review and meta-analysis.

Vascular contribution to cognitive impairment and dementia (VCID) is a clinical label encompassing a wide range of cognitive disorders progressing from mild to major vascular cognitive impairment (VCI), which is also defined as vascular dementia (VaD). VaD diagnosis is mainly based on clinical and imaging findings. Earlier biomarkers are needed to identify subjects at risk to develop mild VCI and VaD. In the present meta-analysis, we comprehensively evaluated the role of inflammatory biomarkers in differential diagnosis between VaD and Alzheimer's disease (AD), and assessed their prognostic value on predicting VaD incidence. We collected literature until January 31, 2021, assessing three inflammatory markers [interleukin(IL)-6, C-reactive protein (CRP), tumor necrosis factor (TNF)-α] from blood or cerebrospinal fluid (CSF) samples. Thirteen cross-sectional and seven prospective studies were included. Blood IL-6 levels were cross-sectionally significantly higher in people with VaD compared to AD patients (SMD: 0.40, 95% CI: 0.18 to 0.62) with low heterogeneity (I2: 41%, p = 0.13). Higher IL-6 levels were also associated to higher risk of incident VaD (relative risk: 1.28, 95% CI: 1.03 to 1.59, I2: 0%). IL-6 in CSF was significantly higher in people with VaD compared to healthy subjects (SMD: 0.77, 95% CI: 0.17 to 1.37, I2: 70%), and not compared to AD patients, but due to limited evidence and high inconsistency across studies, we could not draw definite conclusion. Higher blood IL-6 levels might represent a useful biomarker able to differentiate people with VaD from those with AD and might be correlated with higher risk of future VaD.

Extranuclear effects of thyroid hormones and analogs during development: An old mechanism with emerging roles.

Thyroid hormones, T3 (triiodothyronine) and T4 (thyroxine), induce a variety of long-term effects on important physiological functions, ranging from development and growth to metabolism regulation, by interacting with specific nuclear or cytosolic receptors. Extranuclear or nongenomic effects of thyroid hormones are mediated by plasma membrane or cytoplasmic receptors, mainly by αvß3 integrin, and are independent of protein synthesis. A wide variety of nongenomic effects have now been recognized to be elicited through the binding of thyroid hormones to this receptor, which is mainly involved in angiogenesis, as well as in cell cancer proliferation. Several signal transduction pathways are modulated by thyroid hormone binding to αvß3 integrin: protein kinase C, protein kinase A, Src, or mitogen-activated kinases. Thyroid hormone-activated nongenomic effects are also involved in the regulation of Na+-dependent transport systems, such as glucose uptake, Na+/K+-ATPase, Na+/H+ exchanger, and amino acid transport System A. Of note, the modulation of these transport systems is cell-type and developmental stage-dependent. In particular, dysregulation of Na+/K+-ATPase activity is involved in several pathological situations, from viral infection to cancer. Therefore, this transport system represents a promising pharmacological tool in these pathologies.

Translational insight into prothrombotic state and hypercoagulation in nonalcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) is an emerging and threatening pathological condition, ranging from fatty liver (FL) to chronic steatohepatitis (NASH), liver cirrhosis, and eventually to hepatocellular carcinoma (HCC). Recent findings suggest that patients with NAFLD have a higher risk of cardiovascular events and thromboembolism and that this risk is independent of metabolic diseases that are frequently associated with NAFLD, such as diabetes, hyperlipidaemia, and obesity. The vascular involvement of NAFLD might be considered its systemic burden, conditioning higher mortality in patients affected by the disease. These clinical findings suggested the existence of a prothrombotic state in NAFLD, which is partially unexplored and whose underlying mechanisms are to date not completely understood. Here, we review the mechanisms involved in the pathogenesis of the prothrombotic state in NAFLD across the progression from the healthy liver through the different stages of the disease. We focused on the possible role of several metabolic features of NAFLD possibly leading to hypercoagulation other than endothelial and platelet activation, such as insulin-resistance, nitric oxide production regulation, and gut microbiota homeostasis. Also, we analysed the involvement of plasminogen activator inhibitor-1 (PAI-1) and thromboinflammation taking place in NAFLD. Finally, we described factors striking a prothrombotic imbalance in NASH cirrhosis, with a particular focus on the pathogenesis of portal vein thrombosis.

Treatment of liver cancer cells with ethyl acetate extract of Crithmum maritimum permits reducing sorafenib dose and toxicity maintaining its efficacy.

OBJECTIVES: Hepatocellular carcinoma (HCC) is one of the most frequent tumours worldwide and available drugs are inadequate for therapeutic results and tolerability. Hence, novel effective therapeutic tools with fewer side effects are of paramount importance. We have previously shown that Crithmum maritimum ethyl acetate extract exerts a cytostatic effect in HCC cells. Here, we tested whether C. maritimum ethyl acetate extract in combination with half sorafenib IC50 dose ameliorated efficacy and toxicity of sorafenib in inhibiting liver cancer cell growth. Moreover, we investigated the mechanisms involved. METHODS: Two HCC cell lines (Huh7 and HepG2) were treated with C. maritimum ethyl acetate extract and half IC50 sorafenib dose usually employed in vitro. Then, cell proliferation, growth kinetics and cell toxicity were analysed together with an investigation of the cellular mechanisms involved, focusing on cell cycle regulation and apoptosis. KEY FINDINGS: Results show that combined treatment with C. maritimum ethyl acetate extract and half IC50 sorafenib dose decreased cell proliferation comparably to full-dose sorafenib without increasing cell toxicity as confirmed by the effect on cell cycle regulation and apoptosis. CONCLUSIONS: These results provide scientific support for the possibility of an effective integrative therapeutic approach for HCC with fewer side effects on patients.

1H-NMR metabolomics reveals a multitarget action of Crithmum maritimum ethyl acetate extract in inhibiting hepatocellular carcinoma cell growth.

Hepatocellular carcinoma (HCC) is nowadays the sixth cause of tumour-related deceases worldwide, estimated to become the third in Western countries by 2030. New drugs for HCC treatment still have many adverse effects. Several lines of evidence indicate that plant metabolites offer concrete opportunities for developing new therapeutic strategies for many diseases, including cancer. We previously reported that ethyl acetate extract of a spontaneous edible plant harvested in Apulia, Crithmum maritimum, significantly inhibited cell growth in HCC cells. By 1H-NMR spectroscopy, here we show that Crithmum maritimum ethyl acetate extract counteracts the Warburg effect, by reducing intracellular lactate, inhibits protein anabolism, by decreasing amino acid level, and affects membrane biosynthesis by lowering choline and phosphocholine. Also, we observed an effect on lipid homeostasis, with a reduction in triglycerides, cholesterol, monounsaturated fatty acids (MUFA), and diunsaturated fatty acids (DUFA), and an increase in polyunsaturated fatty acids (PUFA). Taken together, these data demonstrate that Crithmum maritimum-induced cytostasis is exerted through a multi-effect action, targeting key metabolic processes in HCC cells. Overall, our findings highlight the role of Crithmum maritimum as a promising tool for the prevention and the improvement of the therapeutic options for HCC and other types of tumours.

Xanthenylacetic Acid Derivatives Effectively Target Lysophosphatidic Acid Receptor 6 to Inhibit Hepatocellular Carcinoma Cell Growth.

Despite the increasing incidence of hepatocellular carcinoma (HCC) worldwide, current pharmacological treatments are still unsatisfactory. We have previously shown that lysophosphatidic acid receptor 6 (LPAR6) supports HCC growth and that 9-xanthenylacetic acid (XAA) acts as an LPAR6 antagonist inhibiting HCC growth without toxicity. Here, we synthesized four novel XAA derivatives, (±)-2-(9H-xanthen-9-yl)propanoic acid (compound 4 - MC9), (±)-2-(9H-xanthen-9-yl)butanoic acid (compound 5 - MC6), (±)-2-(9H-xanthen-9-yl)hexanoic acid (compound 7 - MC11), and (±)-2-(9H-xanthen-9-yl)octanoic acid (compound 8 - MC12, sodium salt) by introducing alkyl groups of increasing length at the acetic α-carbon atom. Two of these compounds were characterized by X-ray powder diffraction and quantum mechanical calculations, while molecular docking simulations suggested their enantioselectivity for LPAR6. Biological data showed anti-HCC activity for all XAA derivatives, with the maximum effect observed for MC11. Our findings support the view that increasing the length of the alkyl group improves the inhibitory action of XAA and that enantioselectivity can be exploited for designing novel and more effective XAA-based LPAR6 antagonists.

Diiodothyronines regulate metabolic homeostasis in primary human hepatocytes by modulating mTORC1 and mTORC2 activity.

Until three decades, ago 3,5-diiodothyronine (3,5-T2) and 3,3'-diiodothyronine (3,3'-T2) were considered products of thyroid hormone catabolism without biological activity. Some metabolic effects have been described in rodents, but the physiological relevance in humans and the mechanisms of action are unknown. Aim of this work was to investigate the role and the mechanisms of action of 3,5-T2 and 3,3'-T2 in the regulation of metabolic homeostasis in human liver. We used primary human hepatocytes freshly isolated from donors and grown on Matrigel as the golden standard in vitro model to study human hepatic metabolism. Results show that diiodothyronines in the range of plasma physiological concentrations reduced hepatic lipid accumulation, by modulating the activity of the mTORC1/Raptor complex through an AMPK-mediated mechanism, and stimulated the mTORC2/Rictor complex-activated pathway, leading to the down regulation of the expression of key gluconeogenic genes. Hence, we propose that diiodothyronines act as key regulators of hepatic metabolic homeostasis in humans.

Novel lysophosphatidic acid receptor 6 antagonists inhibit hepatocellular carcinoma growth through affecting mitochondrial function.

Hepatocellular carcinoma (HCC) is one of the most prevalent cancers worldwide and the commonest liver cancer. It is expected to become the third leading cause of cancer-related deaths in Western countries by 2030. Effective pharmacological approaches for HCC are still unavailable, and the currently approved systemic treatments are unsatisfactory in terms of therapeutic results, showing many side effects. Thus, searching for new effective and nontoxic molecules for HCC treatment is of paramount importance. We previously demonstrated that lysophosphatidic acid (LPA) is an important contributor to the pathogenesis of HCC and that lysophosphatidic acid receptor 6 (LPAR6) actively supports HCC tumorigenicity. Here, we screened for novel LPAR6 antagonists and found that two compounds, 4-methylene-2-octyl-5-oxotetra-hydrofuran-3-carboxylic acid (C75) and 9-xanthenylacetic acid (XAA), efficiently inhibit HCC growth, both in vitro and in vitro, without displaying toxic effects at the effective doses. We further investigated the mechanisms of action of C75 and XAA and found that these compounds determine a G1-phase cell cycle arrest, without inducing apoptosis at the effective doses. Moreover, we discovered that both molecules act on mitochondrial homeostasis, by increasing mitochondrial biogenesis and reducing mitochondrial membrane potential. Overall, our results show two newly identified LPAR6 antagonists with a concrete potential to be translated into effective and side effect-free molecules for HCC therapy.