Tumor-Induced Hyperlipidemia Contributes to Tumor Growth

Why make it if you can take it: review on extracellular cholesterol uptake and its importance in breast and ovarian cancers

Cholesterol homeostasis is essential for healthy mammalian cells and dysregulation of cholesterol metabolism contributes to the pathogenesis of various diseases including cancer. Cancer cells are dependent on cholesterol. Malignant progression is associated with high cellular demand for cholesterol, and extracellular cholesterol uptake is often elevated in cancer cell to meet its metabolic needs. Tumors take up cholesterol from the blood stream through their vasculature. Breast cancer grows in, and ovarian cancer metastasizes into fatty tissue that provides them with an additional source of cholesterol. High levels of extracellular cholesterol are beneficial for tumors whose cancer cells master the uptake of extracellular cholesterol. In this review we concentrate on cholesterol uptake mechanisms, receptor-mediated endocytosis and macropinocytosis, and how these are utilized and manipulated by cancer cells to overcome their possible intrinsic or pharmacological limitations in cholesterol synthesis. We focus especially on the involvement of lysosomes in cholesterol uptake. Identifying the vulnerabilities of cholesterol metabolism and manipulating them could provide novel efficient therapeutic strategies for treatment of cancers that manifest dependency for extracellular cholesterol.

Integrating lipid metabolite analysis with MRI-based transformer and radiomics for early and late stage prediction of oral squamous cell carcinoma

BACKGROUND

Oral Squamous Cell Carcinoma (OSCC) presents significant diagnostic challenges in its early and late stages. This study aims to utilize preoperative MRI and biochemical indicators of OSCC patients to predict the stage of tumors.

METHODS

This study involved 198 patients from two medical centers. A detailed analysis of contrast-enhanced T1-weighted (ceT1W) and T2-weighted (T2W) MRI were conducted, integrating these with biochemical indicators for a comprehensive evaluation. Initially, 42 clinical biochemical indicators were selected for consideration. Through univariate analysis and multivariate analysis, only those indicators with p-values less than 0.05 were retained for model development. To extract imaging features, machine learning algorithms in conjunction with Vision Transformer (ViT) techniques were utilized. These features were integrated with biochemical indicators for predictive modeling. The performance of model was evaluated using the Receiver Operating Characteristic (ROC) curve.

RESULTS

After rigorously screening biochemical indicators, four key markers were selected for the model: cholesterol, triglyceride, very low-density lipoprotein cholesterol and chloride. The model, developed using radiomics and deep learning for feature extraction from ceT1W and T2W images, showed a lower Area Under the Curve (AUC) of 0.85 in the validation cohort when using these imaging modalities alone. However, integrating these biochemical indicators improved the model's performance, increasing the validation cohort AUC to 0.87.

CONCLUSION

In this study, the performance of the model significantly improved following multimodal fusion, outperforming the single-modality approach.

CLINICAL RELEVANCE STATEMENT

This integration of radiomics, ViT models, and lipid metabolite analysis, presents a promising non-invasive technique for predicting the staging of OSCC.

Role of carboxylesterase and arylacetamide deacetylase in drug metabolism, physiology, and pathology

Carboxylesterases (CES1 and CES2) and arylacetamide deacetylase (AADAC), which are expressed primarily in the liver and/or gastrointestinal tract, hydrolyze drugs containing ester and amide bonds in their chemical structure. These enzymes often catalyze the conversion of prodrugs, including the COVID-19 drugs remdesivir and molnupiravir, to their pharmacologically active forms. Information on the substrate specificity and inhibitory properties of these enzymes, which would be useful for drug development and toxicity avoidance, has accumulated. Recently,in vitroandin vivostudies have shown that these enzymes are involved not only in drug hydrolysis but also in lipid metabolism. CES1 and CES2 are capable of hydrolyzing triacylglycerol, and the deletion of their orthologous genes in mice has been associated with impaired lipid metabolism and hepatic steatosis. Adeno-associated virus-mediated human CES overexpression decreases hepatic triacylglycerol levels and increases fatty acid oxidation in mice. It has also been shown that overexpression of CES enzymes or AADAC in cultured cells suppresses the intracellular accumulation of triacylglycerol. Recent reports indicate that AADAC can be up- or downregulated in tumors of various organs, and its varied expression is associated with poor prognosis in patients with cancer. Thus, CES and AADAC not only determine drug efficacy and toxicity but are also involved in pathophysiology. This review summarizes recent findings on the roles of CES and AADAC in drug metabolism, physiology, and pathology.

Comprehensive analysis on clinical significance and therapeutic targets of LDL receptor related protein 11 (LRP11) in liver hepatocellular carcinoma

LDL lipoprotein receptor-related protein 11 (LRP11) plays a role in several tumors. However, their roles in hepatocellular carcinoma remain unclear. The present study aimed to explore the expression profile and prognostic value of LRP11 in liver hepatocellular carcinoma (LIHC) patients using various cancer databases and bioinformatic tools. In bioinformatics analysis, The Cancer Genome Atlas datasets showed increased LRP11 expression in tumor tissues compared to that in non-tumor tissues in various cancers. Moreover, patients with high expression LRP11 correlated with poor prognosis and clinical features. The LRP11 expression positively correlated with the infiltration of immune cells such as macrophages, neutrophils, and myeloid-derived suppressor cells and a combination of high LRP11 expression and high immune infiltrates was associated with the worst survival in LIHC tumors. Our results also indicated that LRP11 expression was closely associated with immune-modulate function, such as antigen presentation. In DNA methylation profiling, hypomethylation of LRP11 is widely observed in tumors and has prognostic value in LIHC patients. Functional enrichment analysis revealed that LIHC-specific LRP11 interacting genes are involved in protein binding, intracellular processing, and G-protein-related signaling pathways. Analyses of drug sensitivity and immune checkpoint inhibitor predict a number of drugs that could potentially be used to target LRP11. In addition, in vitro experiments verified the promoting effect of LRP11 on the migration, invasion, and colony formation capacity of hepatocellular carcinoma cells. Collectively, our results aided a better understanding of the clinical significance of LRP11 in gene expression, functional interactions, and epigenetic regulation in LIHC and suggested that it may be a useful prognostic biomarker for LIHC patients.

The Causal Relationship between PCSK9 Inhibitors and Malignant Tumors: A Mendelian Randomization Study Based on Drug Targeting

Objective: This study explores the potential causal association between proprotein convertase subtilisin/kexin 9 (PCSK9) inhibitors and tumor development using Mendelian randomization (MR) based on drug targets. Methods: Instrumental variables within ±100 kb of the PCSK9 gene locus, impacting low-density lipoprotein cholesterol (LDL-C), were utilized for MR analysis. Coronary heart disease (CHD) served as a positive control to validate the causal relationship between PCSK9 inhibitors and various cancers. We employed reverse MR to address the reverse causation concerns. Data from positive controls and tumors were sourced from OpenGWAS. Results: MR analysis suggested a negative causal relationship between PCSK9 inhibitors and both breast and lung cancers (95%CIBreast cancer 0.81~0.99, p = 2.25 × 10-2; 95%CILung cancer 0.65~0.94, p = 2.55 × 10-3). In contrast, a positive causal link was observed with gastric, hepatic, and oral pharyngeal cancers and cervical intraepithelial neoplasia (95%CIGastric cancer 1.14~1.75, p = 1.88 × 10-2; 95%CIHepatic cancer 1.46~2.53, p = 1.16 × 10-2; 95%CIOral cavity and pharyngeal cancer 4.49~6.33, p = 3.36 × 10-4; 95%CICarcinoma in situ of cervix uteri 4.56~7.12, p = 6.91 × 10-3), without heterogeneity or pleiotropy (p > 0.05). Sensitivity analyses confirmed these findings. The results of MR of drug targets suggested no causal relationship between PCSK9 inhibitors and bladder cancer, thyroid cancer, pancreatic cancer, colorectal cancer, malignant neoplasms of the kidney (except for renal pelvis tumors), malignant neoplasms of the brain, and malignant neoplasms of the esophagus (p > 0.05). Reverse MR helped mitigate reverse causation effects. Conclusions: The study indicates a divergent causal relationship of PCSK9 inhibitors with certain cancers. While negatively associated with breast and lung cancers, a positive causal association was observed with gastric, hepatic, oral cavity, and pharyngeal cancers and cervical carcinoma in situ. No causal links were found with bladder, thyroid, pancreatic, colorectal, certain kidney, brain, and esophageal cancers.

A potential novel biomarker: comprehensive analysis of prognostic value and immune implication of CES3 in colonic adenocarcinoma

PURPOSE

Colon cancer is the most common malignant tumor in the intestine. Abnormal Carboxylesterases 3 (CES3) expression had been reported to be correlated to multiple tumor progression. However, the association among CES3 expression and prognostic value and immune effects in colonic adenocarcinoma (COAD) were unclear.

PATIENTS AND METHODS

The transcription and expression data of CES3 and corresponding clinical information was downloaded from The Cancer Genome Atlas (TCGA). The CES3 protein expression and the prognostic value were verified based on tissue microarray data. The Cancer immune group Atlas (TCIA), Tumor Immune Dysfunction and Exclusion (TIDE) algorithm and the GSE78220 immunotherapy cohort were used to forecast immunotherapy efficacy. Finally, a prognostic immune signature was constructed and verified.

RESULTS

Compared with normal colon tissues, the expression of mRNA and protein levels of CES3 were downregulated in tumor tissues. CES3 expression was associated with TIICs. Hihg-CES3 COAD patients had better efficacy of concurrent immunotherapy. CES3-related immune genes (CRIs) were identified and were then used to construct prognostic immune signature and had been successfully verified in GES39582.

CONCLUSION

CES3 might be a potential immune-related gene and promising prognostic biomarker in COAD.

Reverse cardio-oncology: A budding concept

Having established the significance of cardiovascular side-effects of anti-neoplastic drugs, present day cardio-oncology has forayed into newer territories buoyed by research into the multiple connections that exist between cardiovascular disease and cancer. An emerging concept of reverse cardio-oncology focuses on the heightened risk of cancer in patients with cardiovascular disease. Common mechanistics of cancer and heart failure (HF) like chronic inflammation and clonal haematopoesis as well as common predisposing factors like obesity and diabetes underline the relation between both cardiovascular disease and various cancers.This review discusses the potential magnitude of the problem, the underlying pathophysiological mechanisms and classification of this novel subject.

Lipid accumulation-mediated histone hypoacetylation drives persistent NK cell dysfunction in anti-tumor immunity

Hyperlipidemia impairs anti-tumor immune responses and is closely associated with increased human cancer incidence and mortality. However, the underlying mechanisms are not well understood. In the present study, we show that natural killer (NK) cells isolated from high-fat-diet mice or treated with oleic acid (OA) in vitro exhibit sustainable functional defects even after removal from hyperlipidemic milieu. This is accompanied by reduced chromatin accessibility in the promoter region of NK cell effector molecules. Mechanistically, OA exposure blunts P300-mediated c-Myc acetylation and shortens its protein half-life in NK cells, which in turn reduces P300 accumulation and H3K27 acetylation and leads to persistent NK cell dysfunction. NK cells engineered with hyperacetylated c-Myc mutants surmount the suppressive effect of hyperlipidemia and display superior anti-tumor activity. Our findings reveal the persistent dysfunction of NK cells in dyslipidemia milieu and extend engineered NK cells as a promising strategy for tumor immunotherapy.

Chimeric Peptide Engineered Nanomedicine for Synergistic Suppression of Tumor Growth and Therapy-Induced Hyperlipidemia by mTOR and PCSK9 Inhibition

Chemotherapy-induced side effects restrain anti-tumor efficiency, with hyperlipidemia being the most common accompanying disease to cause treatment failure. In this work, a chimeric peptide-engineered nanomedicine (designated as PRS) was fabricated for the synergistic suppression of tumor growth and therapy-induced hyperlipidemia. Within this nanomedicine, the tumor matrix-targeting peptide palmitic-K(palmitic)CREKA can self-assemble into a nano-micelle to encapsulate Rapamycin (mTOR inhibitor) and SBC-115076 (PCSK9 inhibitor). This PRS nanomedicine exhibits a uniform nano-distribution with good stability which enhances intracellular drug delivery and tumor-targeting delivery. Also, PRS was found to synergistically inhibit tumor cell proliferation by interrupting the mTOR pathway and reducing Rapamycin-induced hyperlipidemia by increasing the production of LDLR. In vitro and in vivo results demonstrate the superiority of PRS for systematic suppression of tumor growth and the reduction of hyperlipidemia without initiating any other toxic side effects. This work proposes a sophisticated strategy to inhibit tumor growth and also provides new insights for cooperative management of chemotherapy-induced side effects.

Anlotinib affects systemic lipid metabolism and induces lipid accumulation in human lung cancer cells

BACKGROUND

Anlotinib has demonstrated encouraging clinical outcomes in the treatment of lung cancer, soft tissue sarcoma and thyroid carcinoma. Several clinical studies have shown a relationship between anlotinib treatment and the occurrence of hyperlipidemia. The fundamental mechanisms, however, are still largely unclear. Here, the effect of anlotinib on lipid metabolism in an animal model and human cancer cells was evaluated and the role of lipid metabolism in the antitumor efficacy of anlotinib was investigated.

METHODS

The C57BL/6 J mouse model as well as A549 and H460 human lung cancer cell lines were used to examine the impact of anlotinib on lipid metabolism both in vivo and in vitro. Levels of triglycerides, high-density lipoprotein, low-density lipoprotein (LDL), and total cholesterol in serum or cell samples were determined using assay kits. The expression levels of crucial genes and proteins involved in lipid metabolism were measured by quantitative RT-PCR and Western blotting. Furthermore, exogenous LDL and knockdown of low-density lipoprotein receptor (LDLR) were used in H460 cells to investigate the relevance of lipid metabolism in the anticancer efficacy of anlotinib.

RESULTS

Anlotinib caused hyperlipidemia in C57BL/6 J mice, possibly by downregulating hepatic LDLR-mediated uptake of LDL cholesterol. AMP-activated protein kinase and mammalian target of rapamycin inhibition may also be involved. Additionally, anlotinib enhanced sterol response element binding protein 1/2 nuclear accumulation as well as upregulated LDLR expression in A549 and H460 cells, which may be attributable to intracellular lipid accumulation. Knockdown of LDLR reduced intracellular cholesterol content, but interestingly, anlotinib significantly improved intracellular cholesterol accumulation in LDLR-knockdown cells. Both exogenous LDL and LDLR knockdown decreased the sensitivity of cells to anlotinib.

CONCLUSIONS

Anlotinib modulates host lipid metabolism through multiple pathways. Anlotinib also exerts a significant impact on lipid metabolism in cancer cells by regulating key transcription factors and metabolic enzymes. In addition, these findings suggest lipid metabolism is implicated in anlotinib sensitivity.

Low-Density Lipoprotein Receptor Is a Key Driver of Aggressiveness in Thyroid Tumor Cells

We previously described the role of low-density lipoprotein (LDL) in aggressiveness in papillary thyroid cancer (PTC). Moreover, the MAPK signaling pathway in the presence of BRAF V600E mutation is associated with more aggressive PTC. Although the link between MAPK cascade and LDL receptor (LDLR) expression has been previously described, it is unknown whether LDL can potentiate the adverse effects of PTC through it. We aimed to investigate whether the presence of LDL might accelerate the oncogenic processes through MAPK pathway in presence or absence of BRAF V600E in two thyroid cell lines: TPC1 and BCPAP (wild-type and BRAF V600E, respectively). LDLR, PI3K-AKT and RAS/RAF/MAPK (MEK)/ERK were analyzed via Western blot; cell proliferation was measured via MTT assay, cell migration was studied through wound-healing assay and LDL uptake was analyzed by fluorometric and confocal analysis. TPC1 demonstrated a time-specific downregulation of the LDLR, while BCPAP resulted in a receptor deregulation after LDL exposition. LDL uptake was increased in BCPAP over-time, as well as cell proliferation (20% higher) in comparison to TPC1. Both cell lines differed in migration pattern with a wound closure of 83.5 ± 9.7% after LDL coculture in TPC1, while a loss in the adhesion capacity was detected in BCPAP. The siRNA knockdown of LDLR in LDL-treated BCPAP cells resulted in a p-ERK expression downregulation and cell proliferation modulation, demonstrating a link between LDLR and MAPK pathway. The modulation of BRAF-V600E using vemurafenib-impaired LDLR expression decreased cellular proliferation. Our results suggest that LDLR regulation is cell line-specific, regulating the RAS/RAF/MAPK (MEK)/ERK pathway in the LDL-signaling cascade and where BRAF V600E can play a critical role. In conclusion, targeting LDLR and this downstream signaling cascade, could be a new therapeutic strategy for PTC with more aggressive behavior, especially in those harboring BRAF V600E.

The evolving landscape of PCSK9 inhibition in cancer

Cancer is a disease with a significant global burden in terms of premature mortality, loss of productivity, healthcare expenditures, and impact on mental health. Recent decades have seen numerous advances in cancer research and treatment options. Recently, a new role of cholesterol-lowering PCSK9 inhibitor therapy has come to light in the context of cancer. PCSK9 is an enzyme that induces the degradation of low-density lipoprotein receptors (LDLRs), which are responsible for clearing cholesterol from the serum. Thus, PCSK9 inhibition is currently used to treat hypercholesterolemia, as it can upregulate LDLRs and enable cholesterol reduction through these receptors. The cholesterol-lowering effects of PCSK9 inhibitors have been suggested as a potential mechanism to combat cancer, as cancer cells have been found to increasingly rely on cholesterol for their growth needs. Additionally, PCSK9 inhibition has demonstrated the potential to induce cancer cell apoptosis through several pathways, increase the efficacy of a class of existing anticancer therapies, and boost the host immune response to cancer. A role in managing cancer- or cancer treatment-related development of dyslipidemia and life-threatening sepsis has also been suggested. This review examines the current evidence regarding the effects of PCSK9 inhibition in the context of different cancers and cancer-associated complications.

Increased plasma lipids in triple-negative breast cancer and impairment in HDL functionality in advanced stages of tumors

The association between plasma lipids and breast cancer (BC) has been extensively explored although results are still conflicting especially regarding the relationship with high-density lipoprotein cholesterol (HDLc) levels. HDL mediates cholesterol and oxysterol removal from cells limiting sterols necessary for tumor growth, inflammation, and metastasis and this may not be reflected by measuring HDLc. We addressed recently diagnosed, treatment-naïve BC women (n = 163), classified according to molecular types of tumors and clinical stages of the disease, in comparison to control women (CTR; n = 150) regarding plasma lipids and lipoproteins, HDL functionality and composition in lipids, oxysterols, and apo A-I. HDL was isolated by plasma discontinuous density gradient ultracentrifugation. Lipids (total cholesterol, TC; triglycerides, TG; and phospholipids, PL) were determined by enzymatic assays, apo A-I by immunoturbidimetry, and oxysterols (27, 25, and 24-hydroxycholesterol), by gas chromatography coupled with mass spectrometry. HDL-mediated cell cholesterol removal was determined in macrophages previously overloaded with cholesterol and ¹⁴C-cholesterol. Lipid profile was similar between CTR and BC groups after adjustment per age. In the BC group, lower concentrations of TC (84%), TG (93%), PL (89%), and 27-hydroxicholesterol (61%) were observed in HDL, although the lipoprotein ability in removing cell cholesterol was similar to HDL from CRT. Triple-negative (TN) BC cases presented higher levels of TC, TG, apoB, and non-HDLc when compared to other molecular types. Impaired HDL functionality was observed in more advanced BC cases (stages III and IV), as cholesterol efflux was around 28% lower as compared to stages I and II. The altered lipid profile in TN cases may contribute to channeling lipids to tumor development in a hystotype with a more aggressive clinical history. Moreover, findings reinforce the dissociation between plasma levels of HDLc and HDL functionality in determining BC outcomes.

Interfering with lipid metabolism through targeting CES1 sensitizes hepatocellular carcinoma for chemotherapy

Hepatocellular carcinoma (HCC) is the most common lethal form of liver cancer. Apart from surgical removal and transplantation, other treatments have not yet been well established for patients with HCC. In this study, we found that carboxylesterase 1 (CES1) is expressed at various levels in HCC. We further revealed that blockage of CES1 by pharmacological and genetical approaches leads to altered lipid profiles that are directly linked to impaired mitochondrial function. Mechanistically, lipidomic analyses indicated that lipid signaling molecules, including polyunsaturated fatty acids (PUFAs), which activate PPARα/γ, were dramatically reduced upon CES1 inhibition. As a result, the expression of SCD, a PPARα/γ target gene involved in tumor progression and chemoresistance, was significantly downregulated. Clinical analysis demonstrated a strong correlation between the protein levels of CES1 and SCD in HCC. Interference with lipid signaling by targeting the CES1-PPARα/γ-SCD axis sensitized HCC cells to cisplatin treatment. As a result, the growth of HCC xenograft tumors in NU/J mice was potently slowed by coadministration of cisplatin and CES1 inhibition. Our results, thus, suggest that CES1 is a promising therapeutic target for HCC treatment.

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.

Identification of a Chromosome 1 Substitution Line B6-Chr1BLD as a Novel Hyperlipidemia Model via Phenotyping Screening

Hyperlipidemia is a chronic disease that seriously affects human health. Due to the fact that traditional animal models cannot fully mimic hyperlipidemia in humans, new animal models are urgently needed for basic drug research on hyperlipidemia. Previous studies have demonstrated that the genomic diversity of the wild mice chromosome 1 substitution lines was significantly different from that of laboratory mice, suggesting that it might be accompanied by phenotypic diversity. We first screened the blood lipid-related phenotype of chromosome 1 substitution lines. We found that the male HFD-fed B6-Chr1BLD mice showed more severe hyperlipidemia-related phenotypes in body weight, lipid metabolism and liver lesions. By RNA sequencing and whole-genome sequencing results of B6-Chr1BLD, we found that several differentially expressed single nucleotide polymorphism enriched genes were associated with lipid metabolism-related pathways. Lipid metabolism-related genes, mainly including Aida, Soat1, Scly and Ildr2, might play an initial and upstream role in the abnormal metabolic phenotype of male B6-Chr1BLD mice. Taken together, male B6-Chr1BLD mice could serve as a novel, polygenic interaction-based hyperlipidemia model. This study could provide a novel animal model for accurate clinical diagnosis and precise medicine of hyperlipidemia.

Apolipoproteins: New players in cancers

Apolipoproteins (APOs), the primary protein moiety of lipoproteins, are known for their crucial role in lipid traffic and metabolism. Despite extensive exploration of APOs in cardiovascular diseases, their roles in cancers did not attract enough attention. Recently, research focusing on the roles of APOs in cancers has flourished. Multiple studies demonstrate the interaction of APOs with classical pathways of tumorigenesis. Besides, the dysregulation of APOs may indicate cancer occurrence and progression, thus serving as potential biomarkers for cancer patients. Herein, we summarize the mechanisms of APOs involved in the development of various cancers, their applications as cancer biomarkers and their genetic polymorphism associated with cancer risk. Additionally, we also discuss the potential anti-cancer therapies by virtue of APOs. The comprehensive review of APOs in cancers may advance the understanding of the roles of APOs in cancers and their potential mechanisms. We hope that it will provide novel clues and new therapeutic strategies for cancers.

Mining of transcriptome identifies CD109 and LRP12 as possible biomarkers and deregulation mechanism of T cell receptor pathway in Acute Myeloid Leukemia

Acute Myeloid Leukemia (AML) is a heterogeneous disease with highest mortality compared to other types of leukemia. There is a need to find the gene abnormalities and mechanisms behind them due to their heterogenic nature. The present study is aimed to understand genes, pathways and biomarker proteins influenced by transcriptomic deregulation due to AML. Differentially expressed gene (DEG), protein-protein interaction network, gene ontology, KEGG pathway, variant analysis and secretome analyses were performed using different AML RNAseq datasets. A total of 655 DEGs including 291 up-regulated and 364 down-regulated genes, which were satisfied with a fold change of 1.5 were identified. Top hub genes for AML were identified as TP53, PTPRC and AKT1. This integrative bioinformatics approach revealed the deregulation of T Cell Receptor (TCR) pathway and altered immune response related genes. The survival analysis revealed the associated deregulation of multiple TCR pathway related genes. Variant analysis identified the benign and likely benign nature of many important target genes and markers screened, which were found to have an important role in the progression of AML. DEGs and secretome analysis found out a set of seven molecules represents potential biomarkers for AML. In vitro analytical validation showed overexpression pattern of CD109 and LRP12 in AML cell line and HL-60 cells than the normal human bone marrow-derived stromal cell line HS-5. Here we report first time for CD109 and LRP12 as a possible biomarkers for the diagnostic significance. Amino acid substitutions detected by variant analysis and deregulation of immune checkpoint molecules revealed their role in reducing immune response and inability to fight cancer cells. In conclusion, this study highlights the possibility of new biomarkers for AML and the mechanism of decrease in immune response due to the downregulation of co-stimulatory immune molecules, which needs further clinical validation investigations.

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Using RNA-seq data of AML patients, two biomarkers including CD109 and LRP12 for the diagnostic significance were identified based on DEGs, GO/KEGG, and PPI network analysis.

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The transcriptome mining unmasked the complexity of gene alterations in AML by identifying immune response related genes deregulation and significance of TCR signalling.

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Several genes were identified as AML hub genes by network analysis, variant analysis identified non-synonymous variants in co-stimulatory checkpoint targets and the co-inhibitory targets.

Mild dyslipidemia accelerates tumorigenesis through expansion of Ly6Chi monocytes and differentiation to pro-angiogenic myeloid cells

Cancer and cardiovascular disease (CVD) share common risk factors such as dyslipidemia, obesity and inflammation. However, the role of pro-atherogenic environment and its associated low-grade inflammation in tumor progression remains underexplored. Here we show that feeding C57BL/6J mice with a non-obesogenic high fat high cholesterol diet (HFHCD) for two weeks to induce mild dyslipidemia, increases the pool of circulating Ly6Chi monocytes available for initial melanoma development, in an IL-1β-dependent manner. Descendants of circulating myeloid cells, which accumulate in the tumor microenvironment of mice under HFHCD, heighten pro-angiogenic and immunosuppressive activities locally. Limiting myeloid cell accumulation or targeting VEGF-A production by myeloid cells decrease HFHCD-induced tumor growth acceleration. Reverting the HFHCD to a chow diet at the time of tumor implantation protects against tumor growth. Together, these data shed light on cross-disease communication between cardiovascular pathologies and cancer.

Clinical characteristics and variant analyses of transient infantile hypertriglyceridemia related to GPD1 gene

Objective: Our study aims to summarize and analyze the clinical characteristics of transient infantile hypertriglyceridemia (HTGTI) and variants in the glycerol-3-phosphate dehydrogenase 1 (GPD1) gene and the effect of HTGTI on the protein structure of GPD1.

Methods: Retrospective analysis, using the general data, symptoms, signs, and auxiliary examinations, was performed on patients with HTGTI, which were confirmed by genetic testing in our hospital and reported cases online. The clinical data were analyzed using statistical and bioinformatic approaches.

Results: A total of 31 genetically confirmed HTGTI patients were collected from our hospital and cases reported in the literature. The clinical manifestations showed the median age of onset was 6.0 (1.9, 12.0) months. All the patients had normal psychiatric status, but 22.6% of them presented growth retardation and short stature, 93.5% had hepatomegaly, and 16.1% had splenomegaly. Just a few children were reported with jaundice, cholestasis, and obesity (3.2–6.5%). The laboratory investigations showed that 96.8% of them had hypertriglyceridemia (HTG) with a median level of 3.1 (2.1, 5.5) mmol/L, but only 30.0% had returned to normal during follow-up. In addition, 93.5% of patients had elevated alanine aminotransferase (ALT) with an average level of 92.1 ± 43.5 U/L, while 38.7% had hypercholesterolemia. Upon abdominal imaging, all patients presented fatty liver and liver steatosis, with 66.7% of patients showing hepatic fibrosis. Statistical differences in triglyceride (TG) level were observed in the ≤6 months group compared with the older groups and in the 13 months to 6 years group with >6 years group (H = 22.02, P < 0.05). The restricted cubic spline model showed that severe HTG decreased in the early stage of infants to the normal level; however, it rebounded again to a mild or moderate level after the following days. The genetic test revealed that the main variant types of the GPD1 gene were missense variants (51.6%), followed by splicing variants (35.5%) and nonsense variants (12.9%). Of patients, 87.1% had homozygous variants, with the most frequent loci being c.361-1G > C and c.895G > A.

Conclusion: The common manifestations of HTGTI were HTG, hepatomegaly, elevated liver transaminases, and hepatic steatosis in early infancy. However, the recurrence of aberrant HTG may pose long-term detrimental effects on HTGTI patients.

Low-Density Lipoprotein Receptor-Related Protein 8 at the Crossroad between Cancer and Neurodegeneration

The low-density-lipoprotein receptors represent a family of pleiotropic cell surface receptors involved in lipid homeostasis, cell migration, proliferation and differentiation. The family shares common structural features but also has significant differences mainly due to tissue-specific interactors and to peculiar proteolytic processing. Among the receptors in the family, recent studies place low-density lipoprotein receptor-related protein 8 (LRP8) at the center of both neurodegenerative and cancer-related pathways. From one side, its overexpression has been highlighted in many types of cancer including breast, gastric, prostate, lung and melanoma; from the other side, LRP8 has a potential role in neurodegeneration as apolipoprotein E (ApoE) and reelin receptor, which are, respectively, the major risk factor for developing Alzheimer’s disease (AD) and the main driver of neuronal migration, and as a γ-secretase substrate, the main enzyme responsible for amyloid formation in AD. The present review analyzes the contributions of LDL receptors, specifically of LRP8, in both cancer and neurodegeneration, pointing out that depending on various interactions and peculiar processing, the receptor can contribute to both proliferative and neurodegenerative processes.

Metabolic Reprogramming Helps to Define Different Metastatic Tropisms in Colorectal Cancer

Approximately 25% of colorectal cancer (CRC) patients experience systemic metastases, with the most frequent target organs being the liver and lung. Metabolic reprogramming has been recognized as one of the hallmarks of cancer. Here, metabolic and functional differences between two CRC cells with different metastatic organotropisms (metastatic KM12SM CRC cells to the liver and KM12L4a to the lung when injected in the spleen and in the tail vein of mice) were analysed in comparison to their parental non-metastatic isogenic KM12C cells, for a subsequent investigation of identified metabolic targets in CRC patients. Meta-analysis from proteomic and transcriptomic data deposited in databases, qPCR, WB, in vitro cell-based assays, and in vivo experiments were used to survey for metabolic alterations contributing to their different organotropism and for the subsequent analysis of identified metabolic markers in CRC patients. Although no changes in cell proliferation were observed between metastatic cells, KM12SM cells were highly dependent on oxidative phosphorylation at mitochondria, whereas KM12L4a cells were characterized by being more energetically efficient with lower basal respiration levels and a better redox management. Lipid metabolism-related targets were found altered in both cell lines, including LDLR, CD36, FABP4, SCD, AGPAT1, and FASN, which were also associated with the prognosis of CRC patients. Moreover, CD36 association with lung metastatic tropism of CRC cells was validated in vivo. Altogether, our results suggest that LDLR, CD36, FABP4, SCD, FASN, LPL, and APOA1 metabolic targets are associated with CRC metastatic tropism to the liver or lung. These features exemplify specific metabolic adaptations for invasive cancer cells which stem at the primary tumour.

Cholesterol homeostasis and cancer: a new perspective on the low-density lipoprotein receptor

BACKGROUND

Disturbance of cholesterol homeostasis is considered as one of the manifestations of cancer. Cholesterol plays an essential role in the pleiotropic functions of cancer cells, including mediating membrane trafficking, intracellular signal transduction, and production of hormones and steroids. As a single transmembrane receptor, the low-density lipoprotein receptor (LDLR) can participate in intracellular cholesterol uptake and regulate cholesterol homeostasis. It has recently been found that LDLR is aberrantly expressed in a broad range of cancers, including colon cancer, prostate cancer, lung cancer, breast cancer and liver cancer. LDLR has also been found to be involved in various signaling pathways, such as the MAPK, NF-κB and PI3K/Akt signaling pathways, which affect cancer cells and their surrounding microenvironment. Moreover, LDLR may serve as an independent prognostic factor for lung cancer, breast cancer and pancreatic cancer, and is closely related to the survival of cancer patients. However, the role of LDLR in some cancers, such as prostate cancer, remains controversial. This may be due to the lack of normal feedback regulation of LDLR expression in cancer cells and the severe imbalance between LDLR-mediated cholesterol uptake and de novo biosynthesis of cholesterol.

CONCLUSIONS

The imbalance of cholesterol homeostasis caused by abnormal LDLR expression provides new therapeutic opportunities for cancer. LDLR interferes with the occurrence and development of cancer by modulating cholesterol homeostasis and may become a novel target for the development of anti-cancer drugs. Herein, we systematically review the contribution of LDLR to cancer progression, especially its dysregulation and underlying mechanism in various malignancies. Besides, potential targeting and immunotherapeutic options are proposed.

Grade 4 very severe hypertriglyceridaemia at diagnosis in a child with acute lymphoblastic leukaemia

Dyslipidaemia is seen in nearly all cases of acute lymphoblastic leukaemia (ALL) at diagnosis, with mild hypertriglyceridaemia (HTG) in 61% and reduced high-density lipoprotein in 98% cases. HTG irrespective of severity is due to metabolic derangements associated with tumour cells turnover in haematological malignancies and is generally self-limiting. Very severe HTG with overt lipaemic serum is extremely rare at presentation in ALL. HTG is complicated by thrombosis, osteonecrosis and pancreatitis during induction chemotherapy for ALL with steroids and L-asparginase. A careful monitoring is required during induction chemotherapy in ALL when severe HTG is present at diagnosis. We present a female toddler with ALL, who presented with very severe HTG and grossly lipaemic serum. Her very severe HTG decreased to mildly raised HTG at the end of first week of induction chemotherapy. There was no further complication noticed during induction therapy.

Antitumor activity and molecular mechanism of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a member of the proprotein convertase family of proteins that activate other proteins in cells. Functionally, PCSK9 binds to the receptor of low-density lipoprotein particles (LDL) to regulate cholesterol metabolism and lipoprotein homeostasis in human body. PCSK9 inhibition is a novel pharmacological strategy to control hypercholesterolemia and cardiovascular diseases. Recently accumulating evidence realizes that PCSK9 possesses other roles in cells, such as regulation of tissue inflammatory response, intratumoral immune cell infiltration, and tumor progression. This review discussed the advancement of PCSK9 research on its role and underlying mechanisms in tumor development and progression. For example, PCSK9 inhibition could attenuate progression of breast cancer, glioma, colon tumor, hepatocellular cancer, prostate cancer, and lung adenocarcinoma and promote apoptosis of glioma, prostate cancer, and hepatocellular cancer cells. PCSK9 deficiency could reduce liver metastasis of B16F1 melanoma cells by lowering the circulating cholesterol levels. PCSK9 gene knockdown substantially attenuated mouse tumor growth in vivo by activation of cytotoxic T cells, although PCSK9 knockdown had no effect on morphology and growth rate of different mouse cancer cell lines in vitro. PCSK9 inhibition thus can be used to control human cancers. Future preclinical and clinical studies are warranted to define anti-tumor activity of PCSK9 inhibition.

Feature selection and classification over the network with missing node observations

Jointly analyzing transcriptomic data and the existing biological networks can yield more robust and informative feature selection results, as well as better understanding of the biological mechanisms. Selecting and classifying node features over genome-scale networks has become increasingly important in genomic biology and genomic medicine. Existing methods have some critical drawbacks. The first is they do not allow flexible modeling of different subtypes of selected nodes. The second is they ignore nodes with missing values, very likely to increase bias in estimation. To address these limitations, we propose a general modeling framework for Bayesian node classification (BNC) with missing values. A new prior model is developed for the class indicators incorporating the network structure. For posterior computation, we resort to the Swendsen-Wang algorithm for efficiently updating class indicators. BNC can naturally handle missing values in the Bayesian modeling framework, which improves the node classification accuracy and reduces the bias in estimating gene effects. We demonstrate the advantages of our methods via extensive simulation studies and the analysis of the cutaneous melanoma dataset from The Cancer Genome Atlas.

Attenuation of obesity-induced hyperlipidemia reduces tumor growth

Accumulating evidence suggests that hyperlipidemia is associated with obesity and cancer mortality in humans. We tested the hypotheses that inhibition of microsomal triglyceride transfer protein (MTP) would attenuate obesity-induced hyperlipidemia and reduce tumor growth by treating BCR-ABL B cell tumor-bearing hyperlipidemic obese ob/ob obese mice with a MTP inhibitor. MTP inhibition in tumor-bearing mice reduced concentrations of plasma apoB100 5-fold together with a corresponding decrease in VLDL triacylglycerol (TG) and cholesterol. Inhibition of MTP decreased tumor volume by 50%. MTP inhibitor did not alter tumor cell viability in vitro, suggesting that the in vivo tumor shrinkage effect was related to altered circulating lipids. Tumor volume reduction occurred without change in the protein expression of LDLR, FASN and HMGCR in the tumor, suggesting a lack of compensatory mechanisms in response to decreased hyperlipidemia. Expression of genes encoding GLUT4 and PEPCK was increased 6- and 10-fold, respectively, but no change in the expression of genes encoding regulatory enzymes of glycolysis was observed, suggesting that the tumors were not dependent on or switching to carbohydrates for energy requirement to support their growth. No change of proliferative signaling PI3K/AKT and ERK pathways after MTP inhibition was observed in the tumors. In conclusion, MTP inhibition decreased dyslipidemia and tumor growth in obese, insulin resistant mice. Therefore, decreasing VLDL secretion could be further explored as an adjuvant therapeutic intervention together with standard care to reduce tumor growth in obese patients.

Preclinical Evaluation of Dimethyl Itaconate Against Hepatocellular Carcinoma via Activation of the e/iNOS-Mediated NF-κB-Dependent Apoptotic Pathway

Hepatocellular carcinoma (HCC) is one of the most common tumors affecting a large population worldwide, with the fifth and seventh greatest mortality rates among men and women, respectively, and the third prime cause of mortality among cancer victims. Dimethyl itaconate (DI) has been reported to be efficacious in colorectal cancer by decreasing IL-1β release from intestinal epithelial cells. In this study, diethylnitrosamine (DEN)-induced HCC in male albino Wistar rats was treated with DI as an anticancer drug. The function and molecular mechanism of DI against HCC in vivo were assessed using histopathology, enzyme-linked immunosorbent assay (ELISA), and Western blot studies. Metabolomics using ¹H-NMR was used to investigate metabolic profiles. As per molecular insights, DI has the ability to trigger mitochondrial apoptosis through iNOS- and eNOS-induced activation of the NF-κB/Bcl-2 family of proteins, CytC, caspase-3, and caspase-9 signaling cascade. Serum metabolomics investigations using ¹H-NMR revealed that aberrant metabolites in DEN-induced HCC rats were restored to normal following DI therapy. Furthermore, our data revealed that the DI worked as an anti-HCC agent. The anticancer activity of DI was shown to be equivalent to that of the commercial chemotherapeutic drug 5-fluorouracil.

Lipid Droplets in Cancer: From Composition and Role to Imaging and Therapeutics

Cancer is the second most common cause of death worldwide, having its origin in the abnormal growth of cells. Available chemotherapeutics still present major drawbacks, usually associated with high toxicity and poor distribution, with only a small fraction of drugs reaching the tumour sites. Thus, it is urgent to develop novel therapeutic strategies. Cancer cells can reprogram their lipid metabolism to sustain uncontrolled proliferation, and, therefore, accumulate a higher amount of lipid droplets (LDs). LDs are cytoplasmic organelles that store neutral lipids and are hypothesized to sequester anti-cancer drugs, leading to reduced efficacy. Thus, the increased biogenesis of LDs in neoplastic conditions makes them suitable targets for anticancer therapy and for the development of new dyes for cancer cells imaging. In recent years, cancer nanotherapeutics offered some exciting possibilities, including improvement tumour detection and eradication. In this review we summarize LDs biogenesis, structure and composition, and highlight their role in cancer theranostics.

Annexin A6 and NPC1 regulate LDL-inducible cell migration and distribution of focal adhesions

Cholesterol is considered indispensable for cell motility, but how physiological cholesterol pools enable cells to move forward remains to be clarified. The majority of cells obtain cholesterol from the uptake of Low-Density lipoproteins (LDL) and here we demonstrate that LDL stimulates A431 squamous epithelial carcinoma and Chinese hamster ovary (CHO) cell migration and invasion. LDL also potentiated epidermal growth factor (EGF) -stimulated A431 cell migration as well as A431 invasion in 3-dimensional environments, using organotypic assays. Blocking cholesterol export from late endosomes (LE), using Niemann Pick Type C1 (NPC1) mutant cells, pharmacological NPC1 inhibition or overexpression of the annexin A6 (AnxA6) scaffold protein, compromised LDL-inducible migration and invasion. Nevertheless, NPC1 mutant cells established focal adhesions (FA) that contain activated focal adhesion kinase (pY397FAK, pY861FAK), vinculin and paxillin. Compared to controls, NPC1 mutants display increased FA numbers throughout the cell body, but lack LDL-inducible FA formation at cell edges. Strikingly, AnxA6 depletion in NPC1 mutant cells, which restores late endosomal cholesterol export in these cells, increases their cell motility and association of the cholesterol biosensor D4H with active FAK at cell edges, indicating that AnxA6-regulated transport routes contribute to cholesterol delivery to FA structures, thereby improving NPC1 mutant cell migratory behaviour.

PCSK9 regulates the NODAL signaling pathway and cellular proliferation in hiPSCs

Proprotein convertase subtilisin kexin type 9 (PCSK9) is a key regulator of low-density lipoprotein (LDL) cholesterol metabolism and the target of lipid-lowering drugs. PCSK9 is mainly expressed in hepatocytes. Here, we show that PCSK9 is highly expressed in undifferentiated human induced pluripotent stem cells (hiPSCs). PCSK9 inhibition in hiPSCs with the use of short hairpin RNA (shRNA), CRISPR/cas9-mediated knockout, or endogenous PCSK9 loss-of-function mutation R104C/V114A unveiled its new role as a potential cell cycle regulator through the NODAL signaling pathway. In fact, PCSK9 inhibition leads to a decrease of SMAD2 phosphorylation and hiPSCs proliferation. Conversely, PCSK9 overexpression stimulates hiPSCs proliferation. PCSK9 can interfere with the NODAL pathway by regulating the expression of its endogenous inhibitor DACT2, which is involved in transforming growth factor (TGF) β-R1 lysosomal degradation. Using different PCSK9 constructs, we show that PCSK9 interacts with DACT2 through its Cys-His-rich domain (CHRD) domain. Altogether these data highlight a new role of PCSK9 in cellular proliferation and development.

1H-NMR Plasma Lipoproteins Profile Analysis Reveals Lipid Metabolism Alterations in HER2-Positive Breast Cancer Patients

The lipid tumour demand may shape the host metabolism adapting the circulating lipids composition to its growth and progression needs. This study aims to exploit the straightforward 1H-NMR lipoproteins analysis to investigate the alterations of the circulating lipoproteins' fractions in HER2-positive breast cancer and their modulations induced by treatments. The baseline 1H-NMR plasma lipoproteins profiles were measured in 43 HER2-positive breast cancer patients and compared with those of 28 healthy women. In a subset of 32 patients, longitudinal measurements were also performed along neoadjuvant chemotherapy, after surgery, adjuvant treatment, and during the two-year follow-up. Differences between groups were assessed by multivariate PLS-DA and by univariate analyses. The diagnostic power of lipoproteins subfractions was assessed by ROC curve, while lipoproteins time changes along interventions were investigated by ANOVA analysis. The PLS-DA model distinguished HER2-positive breast cancer patients from the control group with a sensitivity of 96.4% and specificity of 90.7%, mainly due to the differential levels of VLDLs subfractions that were significantly higher in the patients' group. Neoadjuvant chemotherapy-induced a significant drop in the HDLs after the first three months of treatment and a specific decrease in the HDL-3 and HDL-4 subfractions were found significantly associated with the pathological complete response achievement. These results indicate that HER2-positive breast cancer is characterized by a significant host lipid mobilization that could be useful for diagnostic purposes. Moreover, the lipoproteins profiles alterations induced by the therapeutic interventions could predict the clinical outcome supporting the application of 1H-NMR lipoproteins profiles analysis for longitudinal monitoring of HER2-positive breast cancer in large clinical studies.

Lipoproteins as Markers for Monitoring Cancer Progression

Lipoproteins are among the contributors of energy for the survival of cancer cells. Studies indicate there are complex functions and metabolism of lipoproteins in cancer. The current review is aimed at providing updates from studies related to the monitoring of lipoproteins in different types of cancer. This had led to numerous clinical and experimental studies. The review covers the major lipoproteins such as LDL cholesterol (LDL-C), oxidized low-density lipoprotein cholesterol (oxLDL-C), very low-density lipoprotein cholesterol (VLDL-C), and high-density lipoprotein cholesterol (HDL-C). This is mainly due to increasing evidence from clinical and experimental studies that relate association of lipoproteins with cancer. Generally, a significant association exists between LDL-C with carcinogenesis and high oxLDL with metastasis. This warrants further investigations to include Mendelian randomization design and to be conducted in a larger population to confirm the significance of LDL-C and its oxidized form as prognostic markers of cancer.

Association of Serum Anti-PCSK9 Antibody Levels with Favorable Postoperative Prognosis in Esophageal Cancer

Background

Esophageal cancer often appears as postoperative metastasis or recurrence after radical surgery. Although we had previously reported that serum programmed cell death ligand 1 (PD-L1) level correlated with the prognosis of esophageal cancer, further novel biomarkers are required for more precise prediction of the prognosis. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is associated with the cholesterol metabolism. But there was no report of relationship between serum PCSK9 antibody and cancer. Therefore, we investigated whether anti-PCSK9 antibodies could be a novel biomarker for solid cancer.

Methods

Serum levels of anti-PCSK9 antibodies and antigens in patients with solid cancer were analyzed using amplified luminescence proximity homogeneous assay-linked immunosorbent assay (AlphaLISA). The reactivity of serum antibodies against recombinant PCSK9 protein was investigated by Western blotting, and the expression of PCSK9 antigens in esophageal cancer tissues was examined by immunohistochemical staining.

Results

AlphaLISA showed that serum anti-PCSK9 antibody (s-PCSK9-Ab) levels were significantly higher in patients with esophageal cancer, gastric cancer, colorectal cancer, lung cancer, and breast cancer than in healthy donors, and patients with esophageal cancer had the highest levels. The presence of serum antibody in patients was confirmed by Western blotting. There was no apparent correlation between s-PCSK9-Ab and PCSK9 antigen levels. Immunohistochemical staining demonstrated the expression of PCSK9 antigen in both the cytoplasm and nuclear compartments of esophageal squamous cell carcinoma tissue but not in normal tissue. Compared with patients with low s-PCSK9-Ab levels, those with high s-PCSK9-Ab levels had a favorable postoperative prognosis after radical surgery for esophageal cancer. In the multivariate analysis, tumor depth and s-PCSK9-Ab level were identified as independent prognostic factors. In the univariate analysis of clinicopathological features, high PCSK9 antibody levels were not associated with sex, age, location, tumor depth, lymph node status, squamous cell carcinoma antigen, or p53-Ab, whereas they correlated significantly with PD-L1 levels, which were associated with unfavorable prognosis. Correlation between s-PCSK9-Ab and PD-L1 levels was also confirmed in the logistic regression analysis; therefore, low s-PCSK9-Ab levels could discriminate another poor prognosis group other than high-PD-L1 group.

Conclusions

Patients with solid cancer had higher s-PCSK9-Ab levels than healthy donors. High s-PCSK9-Ab levels indicated better prognosis for overall survival after surgery in patients with esophageal cancer.

Local ablation of gastric cancer by reconstituted apolipoprotein B lipoparticles carrying epigenetic drugs

Epigenetic inhibitors have shown anticancer effects. Combination chemotherapy with epigenetic inhibitors has shown high effectiveness in gastric cancer clinical trials, but severe side effect and local progression are the causes of treatment failure. Therefore, we sought to develop an acidity-sensitive drug delivery system to release drugs locally to diminish unfavorable outcome of gastric cancer. In this study, we showed that, as compared with single agents, combination treatment with the demethylating agent 5'-aza-2'-deoxycytidine and HDAC inhibitors Trichostatin A or LBH589 decreased cell survival, blocked cell cycle by reducing number of S-phase cells and expression of cyclins, increased cell apoptosis by inducing expression of Bim and cleaved Caspase 3, and reexpressed tumor suppressor genes more effectively in MGCC3I cells. As a carrier, reconstituted apolipoprotein B lipoparticles (rABLs) could release drugs in acidic environments. Orally administrated embedded drugs not only showed inhibitory effects on gastric tumor growth in a syngeneic orthotopic mouse model, but also reduced the hepatic and renal toxicity. In conclusion, we have established rABL-based nanoparticles embedded epigenetic inhibitors for local treatment of gastric cancer, which have good therapeutic effects but do not cause severe side effects.

MiR-4310 regulates hepatocellular carcinoma growth and metastasis through lipid synthesis

Hepatocellular carcinoma (HCC), which is characterized by reprogrammed lipid metabolism, is a highly malignant tumor with a high incidence and mortality rate. While lipid metabolism is a promising target for HCC therapy, the regulation of lipid metabolism is not well elucidated. Through CRISPR/Cas9 screening, we show that miR-4310 inhibits lipid synthesis by targeting fatty acid synthase (FASN) and stearoyl-CoA desaturase-1 (SCD1). In patients with HCC, miR-4310 is significantly downregulated, and its expression is negatively correlated with expressions of FASN and SCD1. Furthermore, low expression of miR-4310 is associated with poor prognosis. By suppressing SCD1-and FASN-mediated lipid synthesis, miR-4310 inhibits HCC cell proliferation, migration, and invasion in vitro and suppresses HCC tumor growth and metastasis in vivo. Our data indicate that miR-4310 plays an important role in HCC tumor growth and metastasis by regulating the FASN- and SCD1-mediated lipid synthesis pathways. Targeting the miR-4310-FASN/SCD pathway may provide a novel strategy for HCC treatment.

Natural Killer Cell Dysfunction in Obese Patients with Breast Cancer: A Review of a Triad and Its Implications

Natural killer cells (NK cells) are a crucial constituent of the innate immune system as they mediate immunity against viruses, bacteria, parasites, and most importantly, tumor cells. The exact mechanism of how the innate immune system and specifically NK cells interact with cancer cells is complex and is yet to be understood. Several factors that constitute the tumor microenvironment (TME) such as hypoxia and TGF-β are believed to play a role in the complex physiological reaction of NK cells to tumor cells. On the other hand, several risk factors are implicated in the development and progression of breast cancer, most importantly: obesity. Cytokines released from adipose tissue such as adipokines, leptin, and resistin, among others, are also believed to facilitate tumor progression. In this study, we aimed to build a triad of breast cancer, obesity, and NK cell dysfunction to elucidate a link between these pillars on a cellular level. Directing efforts towards solidifying the link between these factors will help in designing a targeted immunotherapy with a low side-effect profile that can revolutionize breast cancer treatment and improve survival in obese patients.

Enhanced triacylglycerol catabolism by carboxylesterase 1 promotes aggressive colorectal carcinoma

The ability to adapt to low-nutrient microenvironments is essential for tumor cell survival and progression in solid cancers, such as colorectal carcinoma (CRC). Signaling by the NF-κB transcription factor pathway associates with advanced disease stages and shorter survival in patients with CRC. NF-κB has been shown to drive tumor-promoting inflammation, cancer cell survival, and intestinal epithelial cell (IEC) dedifferentiation in mouse models of CRC. However, whether NF-κB affects the metabolic adaptations that fuel aggressive disease in patients with CRC is unknown. Here, we identified carboxylesterase 1 (CES1) as an essential NF-κB-regulated lipase linking obesity-associated inflammation with fat metabolism and adaptation to energy stress in aggressive CRC. CES1 promoted CRC cell survival via cell-autonomous mechanisms that fuel fatty acid oxidation (FAO) and prevent the toxic build-up of triacylglycerols. We found that elevated CES1 expression correlated with worse outcomes in overweight patients with CRC. Accordingly, NF-κB drove CES1 expression in CRC consensus molecular subtype 4 (CMS4), which is associated with obesity, stemness, and inflammation. CES1 was also upregulated by gene amplifications of its transcriptional regulator HNF4A in CMS2 tumors, reinforcing its clinical relevance as a driver of CRC. This subtype-based distribution and unfavorable prognostic correlation distinguished CES1 from other intracellular triacylglycerol lipases and suggest CES1 could provide a route to treat aggressive CRC.

PCSK9 and cancer: Rethinking the link

BACKGROUND

Cancer is emerging as a major problem globally, as it accounts for the second cause of death despite medical advances. According to epidemiological and basic studies, cholesterol is involved in cancer progression and there are abnormalities in cholesterol metabolism of cancer cells including prostate, breast, and colorectal carcinomas. However, the importance of cholesterol in carcinogenesis and thereby the role of cholesterol homeostasis as a therapeutic target is still a debated area in cancer therapy. Proprotein convertase subtilisin/kexin type-9 (PCSK9), a serine protease, modulates cholesterol metabolism by attachment to the LDL receptor (LDLR) and reducing its recycling by targeting the receptor for lysosomal destruction. Published research has shown that PCSK9 is also involved in degradation of other LDLR family members namely very-low-density-lipoprotein receptor (VLDLR), lipoprotein receptor-related protein 1 (LRP-1), and apolipoprotein E receptor 2 (ApoER2). As a result, this protein represents an interesting therapeutic target for the treatment of hypercholesterolemia. Interestingly, clinical trials on PCSK9-specific monoclonal antibodies have reported promising results with high efficacy in lowering LDL-C and in turn reducing cardiovascular complications. It is important to note that PCSK9 mediates several other pathways apart from its role in lipid homeostasis, including antiviral activity, hepatic regeneration, neuronal apoptosis, and modulation of various signaling pathways. Furthermore, recent literature has illustrated that PCSK9 is closely associated with incidence and progression of several cancers. In a number of studies, PCSK9 siRNA was shown to effectively suppress the proliferation and invasion of the several studied tumor cells. Hence, a novel application of PCSK9 inhibitors/silencers in cancer/metastasis could be considered. However, due to poor data on effectiveness and safety of PCSK9 inhibitors in cancer, the impact of PCSK9 inhibition in these pathological conditions is still unknown.

SEARCH METHODS

A vast literature search was conducted to find intended studies from 1956 up to 2020, and inclusion criteria were original peer-reviewed publications.

PURPOSE OF REVIEW

To date, PCSK9 has been scantly investigated in cancer. The question that needs to be discussed is "How does PCSK9 act in cancer pathophysiology and what are the risks or benefits associated to its inhibition?". We reviewed the available publications highlighting the contribution of this proprotein convertase in pathways related to cancer, with focus on the potential implications of its long-term pharmacological inhibition in cancer therapy.

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.

Immunologic Aspects of Dyslipidemia: a Critical Regulator of Adaptive Immunity and Immune Disorders

Dyslipidemia is a major cause of cardiovascular diseases which represent a leading cause of death in humans. Diverse immune cells are known to be involved in the pathogenesis of cardiovascular diseases such as atherosclerosis. Conversely, dyslipidemia is known to be tightly associated with immune disorders in humans, as evidenced by a higher incidence of atherosclerosis in patients with autoimmune diseases including psoriasis, rheumatoid arthritis, and systemic lupus erythematosus. Given that the dyslipidemia-related autoimmune diseases are caused by autoreactive T cells and B cells, dyslipidemia seems to directly or indirectly regulate the adaptive immunity. Indeed, accumulating evidence has unveiled that proatherogenic factors can impact the differentiation and function of CD4⁺ T cells, CD8⁺ T cells, and B cells. This review discusses an updated overview on the regulation of adaptive immunity by dyslipidemia and proposes a potential therapeutic strategy for immune disorders by targeting lipid metabolism.

Exercise-A Panacea of Metabolic Dysregulation in Cancer: Physiological and Molecular Insights

Metabolic dysfunction is a comorbidity of many types of cancers. Disruption of glucose metabolism is of concern, as it is associated with higher cancer recurrence rates and reduced survival. Current evidence suggests many health benefits from exercise during and after cancer treatment, yet only a limited number of studies have addressed the effect of exercise on cancer-associated disruption of metabolism. In this review, we draw on studies in cells, rodents, and humans to describe the metabolic dysfunctions observed in cancer and the tissues involved. We discuss how the known effects of acute exercise and exercise training observed in healthy subjects could have a positive outcome on mechanisms in people with cancer, namely: insulin resistance, hyperlipidemia, mitochondrial dysfunction, inflammation, and cachexia. Finally, we compile the current limited knowledge of how exercise corrects metabolic control in cancer and identify unanswered questions for future research.

Proprotein Convertase Subtilisin/Kexin Type 9 Promotes Gastric Cancer Metastasis and Suppresses Apoptosis by Facilitating MAPK Signaling Pathway Through HSP70 Up-Regulation

Objective

To examine the effect of proprotein convertase subtilisin/kexin type 9 (PCSK9) on gastric cancer (GC) progression and prognosis, and to explore the underlying mechanism.

Methods

PCSK9 expression levels in human GC tissues were determined by quantitative real-time PCR, western blotting, and immunohistochemical assay. PCSK9 serum levels were detected by enzyme-linked immunosorbent assay. The relationships of PCSK9 and GC progression and survival were analyzed using the Chi-square test, Kaplan-Meier analysis, and Cox proportional hazards model. The effect of PCSK9 on cell invasion, migration, and apoptosis were determined in human GC cell lines and mouse xenograft model separately using PCSK9 knockdown and overexpression strategies. The PCSK9 interacting molecules, screened by co-immunoprecipitation combined with LC-MS/MS, were identified by immunofluorescence localization and western blotting. Additionally, the mitogen-activated protein kinase (MAPK) pathway was assessed by western blotting.

Results

PCSK9 mRNA and protein levels were significantly elevated in GC tissues compared with the paired normal tissues at our medical center (P < 0.001). Notably, the up-regulation of PCSK9 expression in GC tissues was related to tumor progression and poor survival. GC patients had higher serum levels of PCSK9 than the age-matched healthy controls (P < 0.001); PCSK9 promoted invasive and migratory ability and inhibited apoptosis in GC cells with no apparent affection in cell proliferation. The silencing of PCSK9 reversed these effects, suppressing tumor metastasis in vitro and in vivo. Furthermore, PCSK9 maintained these functions through up-regulating heat shock protein 70 (HSP70), ultimately facilitating the mitogen-activated protein kinase (MAPK) pathway.

Conclusion

Collectively, our data revealed that high PCSK9 expression levels in GC tissue were correlated with GC progression and poor prognosis and that PCSK9 could promote GC metastasis and suppress apoptosis by facilitating MAPK signaling pathway through HSP70 up-regulation. PCSK9 may represent a novel potential therapeutic target in GC.

Lipid Metabolism in Cancer Cells

Metabolic reprogramming is one of the most critical hallmarks in cancer cells. In the past decades, mounting evidence has demonstrated that, besides the Warburg Effect, lipid metabolism dysregulation is also one of the essential characteristics of cancer cell metabolism. Lipids are water-insoluble molecules with diverse categories of phosphoglycerides, triacylglycerides, sphingolipids, sterols, etc. As the major utilization for energy storage, fatty acids are the primary building blocks for synthesizing triacylglycerides. And phosphoglycerides, sphingolipids, and sterols are the main components constructing biological membranes. More importantly, lipids play essential roles in signal transduction by functioning as second messengers or hormones. Much evidence has shown specific alterations of lipid metabolism in cancer cells. Consequently, the structural configuration of biological membranes, the energy homeostasis under nutrient stress, and the abundance of lipids in the intracellular signal transduction are affected by these alterations. Furthermore, lipid droplets accumulate in cancer cells and function adaptively to different types of harmful stress. This chapter reviews the regulation, functions, and therapeutic benefits of targeting lipid metabolism in cancer cells. Overall, this chapter highlights the significance of exploring more potential therapeutic strategies for malignant diseases by unscrambling lipid metabolism regulation in cancer cells.

Fabrication of Imatinib Mesylate-Loaded Lactoferrin-Modified PEGylated Liquid Crystalline Nanoparticles for Mitochondrial-Dependent Apoptosis in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a major cause of concern as it has substantial morbidity associated with it. Previous reports have ascertained the antiproliferative activity of imatinib mesylate (IMS) against diverse types of carcinomas, but limited bioavailability has also been reported. The present study envisaged optimized IMS-loaded lactoferrin (LF)-modified PEGylated liquid crystalline nanoparticles (IMS-LF-LCNPs) for effective therapy of IMS to HCC via asialoglycoprotein receptor (ASGPR) targeting. Results displayed that IMS-LF-LCNPs presented an optimum particle size of 120.40 ± 2.75 nm, a zeta potential of +12.5 ± 0.23 mV, and 73.94 ± 2.69% release. High-resolution transmission electron microscopy and atomic force microscopy were used to confirm the surface architecture of IMS-LF-LCNPs. The results of cytotoxicity and 4,6-diamidino-2-phenylindole revealed that IMS-LF-LCNPs had the highest growth inhibition and significant apoptotic effects. Pharmacokinetics and biodistribution studies showed that IMS-LF-LCNPs have superior pharmacokinetic performance and targeted delivery compared to IMS-LCNPs and plain IMS, which was attributed to the targeting action of LF that targets the ASGPR in hepatic cells. Next, our in vivo experiment established that the HCC environment existed due to suppression of BAX, cyt c, BAD, e-NOS, and caspase (3 and 9) genes, which thus owed upstream expression of Bcl-xl, iNOS, and Bcl-2 genes. The excellent therapeutic potential of IMS-LF-LCNPs began the significant stimulation of caspase-mediated apoptotic signals accountable for its anti-HCC prospect. ¹H nuclear magnetic resonance (serum) metabolomics revealed that IMS-LF-LCNPs are capable of regulating the disturbed levels of metabolites linked to HCC triggered through N-nitrosodiethylamine. Therefore, IMS-LF-LCNPs are a potentially effective formulation against HCC.

Fumonisin B1 regulates LDL receptor and ABCA1 expression in an LXR dependent mechanism in liver (HepG2) cells

The metabolic toxicity of Fumonisin B₁ (FB₁) converges at the accumulation of sphingoid bases and reduced ceramide levels. Several studies have alluded to a hypercholesterolemic endpoint after FB₁ exposure, yet the molecular mechanisms remain elusive. Cell surface receptors are important regulators of cholesterol metabolism by regulating influx of lipids and efflux of cholesterol. Western blot analysis showed that FB₁ elevates the expression of ABCA1 (a cholesterol efflux promoter) in an LXR dependent mechanism. We further highlight the potential role of PCSK9 in the degradation of LDL receptor. These data provide important evidence for the mechanism underlying hypercholesterolemia in FB₁ treated models. The disruption of lipid homeostasis by FB₁ is beginning to shift away from canonical ceramide synthase inhibition, and this changed perspective may shed light on diseases caused by dysregulated cholesterol metabolism such as cancer initiation and promotion.

Noninvasive, longitudinal imaging-based analysis of body adipose tissue and water composition in a melanoma mouse model and in immune checkpoint inhibitor-treated metastatic melanoma patients

Background

As cancer cachexia (CC) is associated with cancer progression, early identification would be beneficial. The aim of this study was to establish a workflow for automated MRI-based segmentation of visceral (VAT) and subcutaneous adipose tissue (SCAT) and lean tissue water (LTW) in a B16 melanoma animal model, monitor diseases progression and transfer the protocol to human melanoma patients for therapy assessment.

Methods

For in vivo monitoring of CC B16 melanoma-bearing and healthy mice underwent longitudinal three-point DIXON MRI (days 3, 12, 17 after subcutaneous tumor inoculation). In a prospective clinical study, 18 metastatic melanoma patients underwent MRI before, 2 and 12 weeks after onset of checkpoint inhibitor therapy (CIT; n = 16). We employed an in-house MATLAB script for automated whole-body segmentation for detection of VAT, SCAT and LTW.

Results

B16 mice exhibited a CC phenotype and developed a reduced VAT volume compared to baseline (B16 − 249.8 µl, − 25%; controls + 85.3 µl, + 10%, p = 0.003) and to healthy controls. LTW was increased in controls compared to melanoma mice. Five melanoma patients responded to CIT, 7 progressed, and 6 displayed a mixed response. Responding patients exhibited a very limited variability in VAT and SCAT in contrast to others. Interestingly, the LTW was decreased in CIT responding patients (− 3.02% ± 2.67%; p = 0.0034) but increased in patients with progressive disease (+ 1.97% ± 2.19%) and mixed response (+ 4.59% ± 3.71%).

Conclusion

MRI-based segmentation of fat and water contents adds essential additional information for monitoring the development of CC in mice and metastatic melanoma patients during CIT or other treatment approaches.