Liver X receptor agonist T0901317 inhibits the migration and invasion of non-small-cell lung cancer cells in vivo and in vitro

Ergosterol and its metabolites as agonists of Liver X receptor and their anticancer potential in colorectal cancer

Aberrant cholesterol homeostasis is a well-recognized hallmark of cancer and is implicated in metastasis as well as chemotherapeutic resistance, the two major causes of cancer associated mortality. Liver X receptors (LXRs) are the key transcription factors that induce cholesterol efflux via enhancing the expression of ABCA1 and ABCG1. Therefore, a comprehensive analysis of several novel sterols namely ergosta-7,22,24(28)-trien-3β-ol (Erg1), ergosta-5,22,25-trien-3-ol (Erg2), ergosta-5,7,22,24(28)-tetraen-3β-ol (Erg3), and ergosta-7,22-dien-3β-ol (Erg4) as LXR agonists has been performed. Molecular docking studies have shown that these sterols possess higher binding affinities for LXRs as compared to the reference ligands (GW3965 and TO901317) and also formed critical activating interactions. Molecular dynamic (MD) simulations further confirmed that docking complexes made of these sterols possess significant stability. To assess the extent of LXR activation, ABCA1 promoter was cloned into luciferase reporter plasmid and transfected into HCT116 cells. It was observed that treatment with Erg, Erg 2 and Erg4 led to a significant LXR activation with an EC50 of 5.64µM, 4.83 and 3.03µM respectively. Furthermore, a significant increase in mRNA expression of NR1H2 and LXR target genes i.e. ABCA1, ABCG1 and ApoE was observed upon Erg treatment. Flow cytometric analysis have revealed a significant increase in the accumulation of ABCA1 upon Erg treatment. Cytotoxicity studies conducted on colorectal cancer cell and normal epithelial cell line showed that these sterols are selectively toxic towards cancer cells. Taken together, our findings suggests that ergosterol activates LXRs, have significant anticancer activity and could be a likely candidate to manage aberrant cholesterol homeostasis.

Cholesterol metabolism in tumor microenvironment: cancer hallmarks and therapeutic opportunities

Cholesterol is crucial for cell survival and growth, and dysregulation of cholesterol homeostasis has been linked to the development of cancer. The tumor microenvironment (TME) facilitates tumor cell survival and growth, and crosstalk between cholesterol metabolism and the TME contributes to tumorigenesis and tumor progression. Targeting cholesterol metabolism has demonstrated significant antitumor effects in preclinical and clinical studies. In this review, we discuss the regulatory mechanisms of cholesterol homeostasis and the impact of its dysregulation on the hallmarks of cancer. We also describe how cholesterol metabolism reprograms the TME across seven specialized microenvironments. Furthermore, we discuss the potential of targeting cholesterol metabolism as a therapeutic strategy for tumors. This approach not only exerts antitumor effects in monotherapy and combination therapy but also mitigates the adverse effects associated with conventional tumor therapy. Finally, we outline the unresolved questions and suggest potential avenues for future investigations on cholesterol metabolism in relation to cancer.

The cell line models to study tyrosine kinase inhibitors in non-small cell lung cancer with mutations in the epidermal growth factor receptor: A scoping review

Non-Small Cell Lung Cancer (NSCLC) represents ∼85% of all lung cancers and ∼15-20% of them are characterized by mutations affecting the Epidermal Growth Factor Receptor (EGFR). For several years now, a class of tyrosine kinase inhibitors was developed, targeting sensitive mutations affecting the EGFR (EGFR-TKIs). To date, the main burden of the TKIs employment is due to the onset of resistance mutations. This scoping review aims to resume the current situation about the cell line models employed for the in vitro evaluation of resistance mechanisms induced by EGFR-TKIs in oncogene-addicted NSCLC. Adenocarcinoma results the most studied NSCLC histotype with the H1650, H1975, HCC827 and PC9 mutated cell lines, while Gefitinib and Osimertinib the most investigated inhibitors. Overall, data collected frame the current advancement of this topic, showing a plethora of approaches pursued to overcome the TKIs resistance, from RNA-mediated strategies to the innovative combination therapies.

Recent advancements in nanomedicine based lipid metabolism for tumour immunotherapy

Therapy on lipid metabolism is emerging as a groundbreaking cancer treatment, offering the unprecedented opportunity to effectively treat and in several cases. Tumorigenesis is inextricably linked to lipid metabolism. In this regard, the features of lipid metabolism include lipid synthesis, decomposition, metabolism and lipid storage and mobilisation from intracellular lipid droplets. Most importantly, the regulation of lipid metabolism is central to the appropriate immune response of tumour cells, and ultimately to exert the immune efforts to realise the perspective of many anti-tumour effects. Different cancers and immune cells have different dependence on lipid metabolism, playing a pivotal role in differentiation and function of immune cells. However, what lies before the immunotherapy targeting lipid metabolism is side effects of systemic toxicity and defects of individual drugs, which strongly highlights that nanodelivery strategy is a magnet for it to enhance drug efficiency, reduce drug toxicity and improve application deficiencies. This review will first focus on emerging research progress of lipid metabolic reprogramming mechanism, and then explore the complex role of lipid metabolism in the tumour cells including the effect on immune cells and their nano-preparations of monotherapy and multiple therapies used in combination, in a shift away from conventional cancer research.HighlightsThe regulation of lipid metabolism is central to the appropriate immune response of tumour cells, and ultimately to exert the immune efforts to realise the perspective of many anti-tumour effects.Preparations of focusing lipid metabolism have side effects of systemic toxicity and defects of individual drugs. It strongly highlights that nanodelivery strategy is a magnet for it to enhance drug efficiency, reduce drug toxicity and improve application deficiencies.This review will first focus on emerging research progress of lipid metabolic reprogramming mechanism, and then explore the complex role of lipid metabolism in the tumour cells including the effect on immune cells as well as their nano-preparations of monotherapy and multiple therapies used in combination, in a shift away from conventional cancer research.

The role of cholesterol metabolism in tumor therapy, from bench to bed

Cholesterol and its metabolites have important biological functions. Cholesterol is able to maintain the physical properties of cell membrane, play an important role in cellular signaling, and cellular cholesterol levels reflect the dynamic balance between biosynthesis, uptake, efflux and esterification. Cholesterol metabolism participates in bile acid production and steroid hormone biosynthesis. Increasing evidence suggests a strict link between cholesterol homeostasis and tumors. Cholesterol metabolism in tumor cells is reprogrammed to differ significantly from normal cells, and disturbances of cholesterol balance also induce tumorigenesis and progression. Preclinical and clinical studies have shown that controlling cholesterol metabolism suppresses tumor growth, suggesting that targeting cholesterol metabolism may provide new possibilities for tumor therapy. In this review, we summarized the metabolic pathways of cholesterol in normal and tumor cells and reviewed the pre-clinical and clinical progression of novel tumor therapeutic strategy with the drugs targeting different stages of cholesterol metabolism from bench to bedside.

Targeting Nuclear Receptors in Lung Cancer—Novel Therapeutic Prospects

Lung cancer, the second most commonly diagnosed cancer, is the major cause of fatalities worldwide for both men and women, with an estimated 2.2 million new incidences and 1.8 million deaths, according to GLOBOCAN 2020. Although various risk factors for lung cancer pathogenesis have been reported, controlling smoking alone has a significant value as a preventive measure. In spite of decades of extensive research, mechanistic cues and targets need to be profoundly explored to develop potential diagnostics, treatments, and reliable therapies for this disease. Nuclear receptors (NRs) function as transcription factors that control diverse biological processes such as cell growth, differentiation, development, and metabolism. The aberrant expression of NRs has been involved in a variety of disorders, including cancer. Deregulation of distinct NRs in lung cancer has been associated with numerous events, including mutations, epigenetic modifications, and different signaling cascades. Substantial efforts have been made to develop several small molecules as agonists or antagonists directed to target specific NRs for inhibiting tumor cell growth, migration, and invasion and inducing apoptosis in lung cancer, which makes NRs promising candidates for reliable lung cancer therapeutics. The current work focuses on the importance of various NRs in the development and progression of lung cancer and highlights the different small molecules (e.g., agonist or antagonist) that influence NR expression, with the goal of establishing them as viable therapeutics to combat lung cancer.

Hepatic steatosis and respiratory diseases: a new panorama

Non-alcoholic fatty liver disease is defined as hepatic fat accumulation in more than 5% of hepatocytes, without other liver steatosis causes. It comprises a broad spectrum that can range from benign steatosis and progress to non-alcoholic steatohepatitis, fibrosis, and ultimately hepatocellular carcinoma. Non-alcoholic fatty liver is considered a multisystemic disease since it is related to multiple disorders, such as type 2 diabetes mellitus, polycystic ovary syndrome, chronic kidney disease, psoriasis, osteoporosis, hypothyroidism, cardiovascular diseases, and obstructive sleep apnea syndrome; it is becoming increasingly clear that it is also a risk factor for developing certain respiratory diseases. This article aims to understand the liver and chronic obstructive pulmonary disease mechanisms, obstructive sleep apnea syndrome, asthma, and lung cancer. Given that non-alcoholic fatty liver disease has a considerable impact on the patient's well-being and life quality, as well as on the costs they generate for the country's health services, it is essential to continue research, especially in areas such as the respiratory tract, as there is much misinformation about it.

Cytoplasmic LXR expression is an independent marker of poor prognosis for patients with early stage primary breast cancer

Purpose

The aim of this study was to investigate the expression of liver X receptors α/β (LXR) in primary breast cancer (BC) tissues and to analyze its correlations with clinicopathological parameters including patient survival.

Methods

In a well-characterized cohort of 305 primary BC, subcellular distribution of LXR was evaluated by immunohistochemistry. Correlations with clinicopathological characteristics as well as with patient outcome were analyzed.

Results

LXR was frequently localized in both nuclei and cytoplasms of BC cells, with stronger staining in nuclei. Total and nuclear LXR expression was positively correlated with ER and PR status. Overall survival analysis demonstrated that cytoplasmic LXR was significantly correlated with poor survival and appeared as an independent marker of poor prognosis, in stage I but not in stage II–III tumors

Conclusion

Altogether, these data suggest that cytoplasmic LXR could be defined as a prognostic marker in early stage primary BC.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00432-021-03670-y.

Cholesterol Metabolic Reprogramming in Cancer and Its Pharmacological Modulation as Therapeutic Strategy

Cholesterol is a ubiquitous sterol with many biological functions, which are crucial for proper cellular signaling and physiology. Indeed, cholesterol is essential in maintaining membrane physical properties, while its metabolism is involved in bile acid production and steroid hormone biosynthesis. Additionally, isoprenoids metabolites of the mevalonate pathway support protein-prenylation and dolichol, ubiquinone and the heme a biosynthesis. Cancer cells rely on cholesterol to satisfy their increased nutrient demands and to support their uncontrolled growth, thus promoting tumor development and progression. Indeed, transformed cells reprogram cholesterol metabolism either by increasing its uptake and de novo biosynthesis, or deregulating the efflux. Alternatively, tumor can efficiently accumulate cholesterol into lipid droplets and deeply modify the activity of key cholesterol homeostasis regulators. In light of these considerations, altered pathways of cholesterol metabolism might represent intriguing pharmacological targets for the development of exploitable strategies in the context of cancer therapy. Thus, this work aims to discuss the emerging evidence of in vitro and in vivo studies, as well as clinical trials, on the role of cholesterol pathways in the treatment of cancer, starting from already available cholesterol-lowering drugs (statins or fibrates), and moving towards novel potential pharmacological inhibitors or selective target modulators.

Influence of cholesterol on cancer progression and therapy

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Abnormality in blood cholesterol level is significantly correlated with risk of different cancers.

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Majority of tumor tissue from cancer patient exhibits overexpression of LDLR and ACAT for supporting rapid cancer cell proliferation.

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Alteration of the cholesterol metabolism in cancer cells hampers therapeutic response.

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Targeting cholesterol metabolism for treatment of cancer with other conventional chemotherapeutic drugs appears to be beneficial.

Cholesterol is a fundamental molecule necessary for the maintenance of cell structure and is vital to various normal biological functions. It is a key factor in lifestyle-related diseases including obesity, diabetes, cardiovascular disease, and cancer. Owing to its altered serum chemistry status under pathological states, it is now being investigated to unravel the mechanism by which it triggers various health complications. Numerous clinical studies in cancer patients indicate an alteration in blood cholesterol level (either decreased or increased) in comparison to normal healthy individuals. This article elaborates on our understanding as to how cholesterol is being hijacked in the malignancy for the development, survival, stemness, progression, and metastasis of cancerous cells. Also, it provides a glimpse of how cholesterol derived entities, alters the signaling pathway towards their advantage. Moreover, deregulation of the cholesterol metabolism pathway has been often reported to hamper various treatment strategies in different cancer. In this context, attempts have been made to bring forth its relevance in being targeted, in pre-clinical and clinical studies for various treatment modalities. Thus, understanding the role of cholesterol and deciphering associated molecular mechanisms in cancer progression and therapy are of relevance towards improvement in the management of various cancers.

Modulation of LXR signaling altered the dynamic activity of human colon adenocarcinoma cancer stem cells in vitro

BACKGROUND

The expansion and metastasis of colorectal cancers are closely associated with the dynamic growth of cancer stem cells (CSCs). This study aimed to explore the possible effect of LXR (a regulator of glycolysis and lipid hemostasis) in the tumorgenicity of human colorectal CD133 cells.

METHODS

Human HT-29 CD133⁺ cells were enriched by MACS and incubated with LXR agonist (T0901317) and antagonist (SR9243) for 72 h. Cell survival was evaluated using MTT assay and flow cytometric analysis of Annexin-V. The proliferation rate was measured by monitoring Ki-67 positive cells using IF imaging. The modulation of LXR was studied by monitoring the activity of all factors related to ABC transporters using real-time PCR assay and western blotting. Protein levels of metabolic enzymes such as PFKFB3, GSK3β, FASN, and SCD were also investigated upon treatment of CSCs with LXR modulators. The migration of CSCs was monitored after being exposed to LXR agonist using scratch and Transwell insert assays. The efflux capacity was measured using hypo-osmotic conditions. The intracellular content of reactive oxygen species was studied by DCFH-DA staining.

RESULTS

Data showed incubation of CSCs with T0901317 and SR9243 reduced the viability of CD133 cells in a dose-dependent manner compared to the control group. The activation of LXR up-regulated the expression and protein levels of ABC transporters (ABCA1, ABCG5, and ABCG8) compared to the non-treated cells (p < 0.05). Despite these effects, LXR activation suppressed the proliferation, clonogenicity, and migration of CD133 cells, and increased hypo-osmotic fragility (p < 0.05). We also showed that SR9243 inhibited the proliferation and clonogenicity of CD133 cells through down-regulating metabolic enzymes PFKFB3, GSK3β, FASN, and SCD as compared with the control cells (p < 0.05). Intracellular ROS levels were increased after the inhibition of LXR by SR9243 (p < 0.05). Calling attention, both T0901317 and SR9243 compounds induced apoptotic changes in cancer stem cells (p < 0.05).

CONCLUSIONS

The regulation of LXR activity can be considered as a selective targeting of survival, metabolism, and migration in CSCs to control the tumorigenesis and metastasis in patients with advanced colorectal cancers.

Shedding light on the roles of liver X receptors in cancer by using chemical probes

Nuclear receptors, liver X receptor-α (LXRα; NR1H3) and liver X receptor-β (LXRβ; NR1H2), are considered master regulators of lipid homeostasis. During the last couple of decades, their pivotal roles in several physiological and pathological processes ranging from energy supply, immunity, cardiovascular, neurodegenerative disorders and cancer have been highlighted. In this review, the main results achieved during more recent years about our understanding of the LXR involvement in cancer has been mainly obtained using small-molecule chemical probes. Remarkably, all these probes, albeit having different structure and biological properties, have a well demonstrated anti-tumoral activity arising from LXR modulation, indicating a high potential of LXR targeting for the treatment of cancer. LINKED ARTICLES: This article is part of a themed issue on Oxysterols, Lifelong Health and Therapeutics. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.16/issuetoc.

Bioinformatics analysis and identification of circular RNAs promoting the osteogenic differentiation of human bone marrow mesenchymal stem cells on titanium treated by surface mechanical attrition

BACKGROUND

To analyze and identify the circular RNAs (circRNAs) involved in promoting the osteogenic differentiation of human bone mesenchymal stem cells (hBMSCs) on titanium by surface mechanical attrition treatment (SMAT).

METHODS

The experimental material was SMAT titanium and the control material was annealed titanium. Cell Counting Kits-8 (CCK-8) was used to detect the proliferation of hBMSCs, and alkaline phosphatase (ALP) activity and alizarin red staining were used to detect the osteogenic differentiation of hBMSCs on the sample surfaces. The bioinformatics prediction software miwalk3.0 was used to construct competing endogenous RNA (ceRNA) networks by predicting circRNAs with osteogenesis-related messenger RNAs (mRNAs) and microRNAs (miRNAs). The circRNAs located at the key positions in the networks were selected and analyzed by quantitative real-time PCR (QRT-PCR).

RESULTS

Compared with annealed titanium, SMAT titanium could promote the proliferation and osteogenic differentiation of hBMSCs. The total number of predicted circRNAs was 51. Among these, 30 circRNAs and 8 miRNAs constituted 6 ceRNA networks. Circ-LTBP2 was selected for verification. QRT-PCR results showed that the expression levels of hsa_circ_0032599, hsa_circ_0032600 and hsa_circ_0032601 were upregulated in the experimental group compared with those in the control group; the differential expression of hsa_circ_0032600 was the most obvious and statistically significant, with a fold change (FC) = 4.25 ± 1.60, p-values (p) < 0.05.

Obesity and nonalcoholic fatty liver disease associated with adenocarcinoma in patients with lung cancer

Lung cancer has become the leading cause of cancer-related deaths around the world. In addition to genetic risk factors and smoking, the metabolic risk factors remain to be elusive.To evaluate the associations between obesity, nonalcoholic fatty liver disease (NAFLD) and pulmonary adenocarcinoma in patients with lung cancer.Consecutive operation-proven lung cancer patients with assessment of metabolic disorders and liver ultrasound in 2009 and 2013 were retrospectively enrolled. T-test and multivariate logistic regression were applied to evaluate the contribution of individual factors to lung adenocarcinoma, as well as the synergistic effects between these factors.Among 3664 lung cancer patients with ultrasound examination, 2844 cases were enrolled for further analysis. Of them, 1053 (37.0%) were females, 1242 (43.7%) were cigarette smokers, 1658 (58.3%) were diagnosed as lung adenocarcinoma, 744 (26.2%) had obesity, and 614 (21.6%) had NAFLD. Proportion of female gender, nonsmoker, obesity, NAFLD, and serum lipid levels in patients with adenocarcinoma were significantly higher than those in other subtypes of lung cancer, and in 2013 than in 2009 (all P < .01). NAFLD and obesity were shown as independent factors and positively associated with pulmonary adenocarcinoma, along with female gender and nonsmoking, higher serum levels of cholesterol. NAFLD and other contributing factors exhibited no synergistic effects on adenocarcinoma.Obesity and NAFLD might increase the risk for pulmonary adenocarcinoma, especially in nonsmoking females, and underscore the need for further study into carcinogenic mechanisms and preventive interventions.