Potential Role of HMGCS2 in Tumor Angiogenesis in Colorectal Cancer and Its Potential Use as a Diagnostic Marker

β-hydroxybutyrate restrains colitis-associated tumorigenesis by inhibiting HIF-1α-mediated angiogenesis

Decreased levels of β-hydroxybutyrate (BHB), a lipid metabolic intermediate known to slow the progression of colorectal cancer (CRC), have been observed in the colon mucosa of patients with inflammatory bowel diseases (IBD). In particular, patients with recurrent IBD present an increased risk of developing colitis-associated colorectal cancer (CAC). The role and molecular mechanism of BHB in the inflammatory and carcinogenic process of CAC remains unclear. Here, the anti-tumor effect of BHB was investigated in the Azoxymethane (AOM)/Dextran Sulfate Sodium (DSS)-induced CAC model and tumor organoids derivatives. The underlying mechanisms were studied using transcriptome and non-target metabolomic assay and further validated in colon tumor cell lineage CT26 in vitro. The tumor tissues and the nearby non-malignant tissues from colon cancer patients were collected to measure the expression levels of ketogenic enzymes. The exogenous BHB supplement lightened tumor burden and angiogenesis in the CAC model. Notably, transcriptome analysis revealed that BHB effectively decreased the expression of VEGFA in the CAC tumor mucosa. In vitro, BHB directly reduced VEGFA expression in hypoxic-treated CT26 cells by targeting transcriptional factor HIF-1α. Conversely, the deletion of HIF-1α largely reversed the inhibitory effect of BHB on CAC tumorigenesis. Additionally, decreased expression of ketogenesis-related enzymes in tumor tissues were associated with poor survival outcomes in patients with colon cancer. In summary, BHB carries out anti-angiogenic activity in CAC by regulating HIF-1α/VEGFA signaling. These findings emphasize the role of BHB in CAC and may provide novel perspectives for the prevention and treatment of colonic tumors.

Induction of resistance to neurotrophic tropomyosin-receptor kinase inhibitors by HMGCS2 via a mevalonate pathway

INTRODUCTION

A neurotrophic tropomyosin receptor kinase (NTRK)-tyrosine kinase inhibitor (TKI) has shown dramatic efficacy against malignant tumors harboring an NTRK fusion gene. However, almost all tumors eventually acquire resistance to NTRK-TKIs.

METHOD

To investigate the mechanism of resistance to NTRK-TKIs, we established cells resistant to three types of NTRK-TKIs (larotrectinib, entrectinib, and selitrectinib) using KM12 colon cancer cells with a TPM3-NTRK1 rearrangement.

RESULT

Overexpression of 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2) was observed in three resistant cells (KM12-LR, KM12-ER, and KM12-SR) by microarray analysis. Lower expression of sterol regulatory element-binding protein 2 (SREBP2) and peroxisome proliferator activated receptor α (PPARα) was found in two cells (KM12-ER and KM12-SR) in which HMGCS2 was overexpressed compared to the parental KM12 and KM12-LR cells. In resistant cells, knockdown of HMGCS2 using small interfering RNA improved the sensitivity to NTRK-TKI. Further treatment with mevalonolactone after HMGCS2 knockdown reintroduced the NTRK-TKI resistance. In addition, simvastatin and silibinin had a synergistic effect with NTRK-TKIs in resistant cells, and delayed tolerance was observed after sustained exposure to clinical concentrations of NTRK-TKI and simvastatin in KM12 cells. In xenograft mouse models, combination treatment with entrectinib and simvastatin reduced resistant tumor growth compared with entrectinib alone.

CONCLUSION

These results suggest that HMGCS2 overexpression induces resistance to NTRK-TKIs via the mevalonate pathway in colon cancer cells. Statin inhibition of the mevalonate pathway may be useful for overcoming this mechanistic resistance.

Improved therapy for clear cell renal cell carcinoma: beta-hydroxybutyrate and quercetin target hypoxia-induced angiogenesis and multidrug resistance

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) is a form of kidney cancer characterized by dysregulated angiogenesis and multidrug resistance. Hypoxia-induced tumor progression plays a crucial role in ccRCC pathogenesis. Beta-hydroxybutyrate (BHB) and quercetin (QCT) have shown potential in targeting angiogenesis and drug resistance in various cancer types. This study investigates the combined effects of BHB and QCT in hypoxia-induced Caki-1 cells.

METHODS

Caki-1 cells were subjected to normoxic and hypoxic conditions and treated with BHB, QCT, or a combination of both. Cell-viability was assessed using the MTT assay, and mRNA expression levels of key angiogenesis-related genes (HIF-1α/2α, VEGF, Ang-1, Ang-2, and MDR4) were quantified through real-time PCR during 24 and 48 h.

RESULTS

BHB and QCT treatments, either alone or in combination, significantly reduced cell-viability in Caki-1 cells (p < 0.05). Moreover, the combined therapy demonstrated a potential effect in downregulating the expression of angiogenesis-related genes and MDR4 in hypoxia-induced cells, with a marked reduction in HIF-1α/2α, VEGF, Ang-1, and MDR4 expression (p < 0.05). The expression of Ang-2 increases significantly in presence of BHB combined QCT treatment.

CONCLUSION

This study highlights the promising potential of a combination therapy involving BHB and QCT in mitigating angiogenesis and MDR4 expression in hypoxia-induced ccRCC cells. These findings support further investigation into the underlying mechanisms and warrant clinical studies to evaluate the therapeutic value of this combined treatment for ccRCC patients. This research provides new insights into addressing the challenges posed by angiogenesis and drug resistance in ccRCC.

ToPP: Tumor online prognostic analysis platform for prognostic feature selection and clinical patient subgroup selection

Patients with cancer with different molecular characterization and subtypes result in different response to anticancer therapeutics and survival. To identify features that are associated with prognosis is essential to precision medicine by providing clues for target identification, drug discovery. Here, we developed a tumor online prognostic analysis platform (ToPP) which integrated eight multi-omics features and clinical data from 68 cancer projects. It provides multiple approaches for customized prognostic studies, including 1) Prognostic analysis based on multi-omics features and clinical characteristics; 2) Automatic construction of prognostic model; 3) Pancancer prognostic analysis in multi-omics data; 4) Explore the impact of different levels of feature combinations on patient prognosis; 5) More sophisticated prognostic analysis according to regulatory network. ToPP provides a comprehensive source and easy-to-use interface for tumor prognosis research, with one-stop service of multi-omics, subtyping, and online prognostic modeling. The web server is freely available at http://www.biostatistics.online/topp/index.php.

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ToPP platform integrated eight multi-omics and clinical data from 68 cancer projects

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ToPP provides multi-omics combination and subgroup selection for prognostic analysis

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ToPP provides automatic construction of prognostic model for public and custom data

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Users can perform prognostic analysis based on regulatory network or pathways in ToPP

Constructing a thyroid cancer prognostic risk model based on CD8+ T cell associated genes

Thyroid cancer (TC) is a common and curable endocrine tumor occurring in the head and neck characterized by a low mortality rate compared to other malignancies. In this study, the immune microenvironment of TC was investigated to identify biomarkers. The mRNA and clinical data available in this study were accessed from The Cancer Genome Atlas-Thyroid Cancer (TCGA-THCA) dataset. Differences in immune infiltration levels of TC and normal samples were assessed by CIBERSORT. Thyroid cancer samples were classified into high- and low-abundance groups according to the median abundance of immune cell infiltration, and CD8⁺ T cells were notably correlated with the survival status. Differential expression analysis was conducted on CD8⁺ T cells to obtain immune-related differentially expressed genes (DEGs). Subsequently, a prognostic risk model was established through Cox regression analysis. According to the median risk score, samples in the training set and validation set were assigned to high- and low-risk groups. The survival and ROC curves demonstrated that the model possesses favorable prognostic prediction ability. Furthermore, the results of gene set enrichment analysis (GSEA) indicated differences between the high- and low-risk groups in terms of ECM receptor interaction and transforming growth factor β (TGF-β) signaling pathways. The tumor microenvironment of TC samples was evaluated by ESTIMATE, which showed that stromal scores were higher in the high-risk group. Finally, simple-sample GSEA (ssGSEA) was performed on TC samples. The results indicated a higher infiltration level of NK cells in the low-risk group, as well as a lower level in the high-risk group. In terms of immune function-related gene sets, genes related to APC co-inhibition, cytolytic activity, HLA and T cell co-inhibition were observed to present higher expression levels in the low-risk group. In general, this study built a 6-gene prognostic risk assessment model based on CD8⁺ T cells through bioinformatics analysis, which is expected to be a reference for clinicians to judge the prognosis of TC patients.

Epigenetic inactivation of hydroxymethylglutaryl CoA synthase reduces ketogenesis and facilitates tumor cell motility in clear cell renal carcinoma

Previously, we have reported that the dysregulation of ketogenesis plays an important role in the carcinogenesis of clear cell renal cell carcinoma (ccRCC). Here, we demonstrate decreased expression of the HMGCS2 gene in ccRCC, a critical enzyme for the synthesis of the ketone body β-hydroxybutyrate (β-OHB). We found that the reduced transcription of the HMGCS2 gene in ccRCC cells was significantly correlated to a higher relative methylation rate in its promotor region. The higher methylation rate in the region of the transcription start site and 1st exon of the HMGCS2 gene was, in turn, correlated with a worse clinical outcome for patients. The transcription of HMGCS2 was possible to restore by treatment with 5-aza-2'-deoxycytidine and with the histone deacetylase inhibitor β-OHB. Therefore, the low levels of the HMGCS2 enzyme in ccRCC may be the consequence of hypermethylation of the HMGCS2 promotor. The ensuing reduction in the ketone body levels further suppresses the transcription of HMGCS2 via a feedback loop. Ectopic expression of HMGCS2 attenuates the migration and invasion of ccRCC but does not affect the proliferative capacity of ccRCC cells in vitro. In addition, we showed that ectopic expression of HMGCS2 boosts the intracellular levels of β-OHB and that exogenously applied β-OHB suppresses the motility and invasion of ccRCC. Our study reveals crosstalk between genes that regulate metabolism and their metabolites, thus providing a better understanding of the epigenetic mechanism involved in ccRCC carcinogenesis and suggesting opportunities for metabolic therapy of tumors. Initially, we suggest that the mRNA level of HMGCS2 could serve as a potentially valuable diagnostic (AUC = 0.918, p < 0.001) and prognostic biomarker.

Blockade of the CD93 pathway normalizes tumor vasculature to facilitate drug delivery and immunotherapy

The immature and dysfunctional vascular network within solid tumors poses a substantial obstacle to immunotherapy because it creates a hypoxic tumor microenvironment that actively limits immune cell infiltration. The molecular basis underpinning this vascular dysfunction is not fully understood. Using genome-scale receptor array technology, we showed here that insulin-like growth factor binding protein 7 (IGFBP7) interacts with its receptor CD93, and we subsequently demonstrated that this interaction contributes to abnormal tumor vasculature. Both CD93 and IGFBP7 were up-regulated in tumor-associated endothelial cells. IGFBP7 interacted with CD93 via a domain different from multimerin-2, the known ligand for CD93. In two mouse tumor models, blockade of the CD93/IGFBP7 interaction by monoclonal antibodies promoted vascular maturation to reduce leakage, leading to reduced tumor hypoxia and increased tumor perfusion. CD93 blockade in mice increased drug delivery, resulting in an improved antitumor response to gemcitabine or fluorouracil. Blockade of the CD93 pathway triggered a substantial increase in intratumoral effector T cells, thereby sensitizing mouse tumors to immune checkpoint therapy. Last, analysis of samples from patients with cancer under anti-programmed death 1/programmed death-ligand 1 treatment revealed that overexpression of the IGFBP7/CD93 pathway was associated with poor response to therapy. Thus, our study identified a molecular interaction involved in tumor vascular dysfunction and revealed an approach to promote a favorable tumor microenvironment for therapeutic intervention.

HMGCS2 in metabolic pathways was associated with overall survival in hepatocellular carcinoma: A LASSO-derived study

This integrated bioinformatic study aimed to investigate potential prognostic candidates in hepatocellular carcinoma (HCC). In the GSE14520, GSE101685, and The Cancer Genome Atlas (TCGA) datasets, differentially expressed genes (DEGs) were identified and functional pathways of common DEGs were enriched. The least absolute shrinkage and selection operator (LASSO) model was used to screen the potential parameters associated with overall survival (OS) in HCC patients. Metabolic pathways were the most significantly enriched functional pathways of common DEGs in these three datasets. After LASSO model analysis, HMGCS2, UGP2, BCLC staging and TNM staging were screened as potential prognostic candidates for OS in HCC patients in GSE14520. HMGCS2 in the metabolic pathway was significantly downregulated in tumor tissues and peripheral blood mononuclear cells in HCC patients (all p < 0.05). Cox regression model indicated that HMGCS2 might be associate with OS in HCC patients in GSE14520 and in the TCGA (p = 0.029 and p = 0.05, respectively). Kaplan-Meier analysis demonstrated that HMGCS2 downregulation in tumors contributed to an unfavorable OS in HCC patients, both in GSE14520 and in the TCGA (p = 0.0001 and p = 0.0002, respectively). Additionally, HMGCS2 was significantly downregulated in HCC patients with high alpha-fetoprotein (AFP), main tumor size >5 cm, multinodular, advanced tumor staging including BCLC, TNM and CLIP (all p < 0.05). HMGCS2 was involved in metabolic pathways, and downregulated HMGCS2 in tumors was associated with unfavorable OS in HCC patients.

Proteomic comparison between different tissue preservation methods for identification of promising biomarkers of urothelial bladder cancer

Samples in biobanks are generally preserved by formalin-fixation and paraffin-embedding (FFPE) and/or optimal cutting temperature compound (OCT)-embedding and subsequently frozen. Mass spectrometry (MS)-based analysis of these samples is now available via developed protocols, however, the differences in results with respect to preservation methods needs further investigation. Here we use bladder urothelial carcinoma tissue of two different tumor stages (Ta/T1-non-muscle invasive bladder cancer (NMIBC), and T2/T3-muscle invasive bladder cancer (MIBC)) which, upon sampling, were divided and preserved by FFPE and OCT. Samples were parallel processed from the two methods and proteins were analyzed with label-free quantitative MS. Over 700 and 1200 proteins were quantified in FFPE and OCT samples, respectively. Multivariate analysis indicates that the preservation method is the main source of variation, but also tumors of different stages could be differentiated. Proteins involved in mitochondrial function were overrepresented in OCT data but missing in the FFPE data, indicating that these proteins are not well preserved by FFPE. Concordant results for proteins such as HMGCS2 (uniquely quantified in Ta/T1 tumors), and LGALS1, ANXA5 and plastin (upregulated in T2/T3 tumors) were observed in both FFPE and OCT data, which supports the use of MS technology for biobank samples and encourages the further evaluation of these proteins as biomarkers.

Identification of potential key genes and key pathways related to clear cell renal cell carcinoma through bioinformatics analysis

Clear cell renal cell carcinoma (ccRCC) is a common malignancy of the genitourinary system and is associated with high mortality rates. However, the molecular mechanism of ccRCC pathogenesis is still unclear, which translates to few effective diagnostic and prognostic biomarkers. In this study, we conducted a bioinformatics analysis on three Gene Expression Omnibus datasets and identified 437 differentially expressed genes (DEGs) related to ccRCC development and prognosis, of which 311 and 126 genes are respectively down-regulated and up-regulated. The protein-protein interaction network of these DEGs consists of 395 nodes and 1872 interactions and 2 prominent modules. The Staphylococcus aureus infection and complement and coagulation cascades are significantly enriched in module 1 and are likely involved in ccRCC progression. Forty-two hub genes were screened, of which von Willebrand factor, TIMP metallopeptidase inhibitor 1, plasminogen, formimidoyltransferase cyclodeaminase, solute carrier family 34 member 1, hydroxyacid oxidase 2, alanine-glyoxylate aminotransferase 2, phosphoenolpyruvate carboxykinase 1, and 3-hydroxy-3-methylglutaryl-CoA synthase 2 are possibly related to the prognosis of ccRCC. The differential expression of all nine genes was confirmed by quantitative real-time polymerase chain reaction analysis of the ccRCC and normal renal tissues. These key genes are potential biomarkers for the diagnosis and prognosis of ccRCC and warrant further investigation.