Inhibition of pyruvate dehydrogenase kinase‑1 by dicoumarol enhances the sensitivity of hepatocellular carcinoma cells to oxaliplatin via metabolic reprogramming

Lactoferrin-encapsulated dichloroacetophenone (DAP) nanoparticles enhance drug delivery and anti-tumor efficacy in prostate cancer

Pyruvate Dehydrogenase Kinase 1 (PDK1) regulates glycolysis and oxidative phosphorylation pathways and is linked to prostate cancer metastasis and poor prognosis. The therapeutic application of 2,2-dichloroacetophenone (DAP), a PDK1 inhibitor, remains underexplored in prostate cancer. In this study we demonstrated that DAP exhibited a superior ability to inhibit prostate cancer cell proliferation, migration and colony formation at a lower concentration (20 μM) compared to a previously established inhibitor, dichloroacetate (DCA), which required concentrations of 30 mM or higher. However, poor aqueous solubility and lower stability of DAP limits its therapeutic application. Nano formulation of DAP with natural lactoferrin enhanced its dispersion and stability by increasing polydispersity index and intensity, and reduced zeta potential values upon conjugation that overcame the solubility limitations of DAP. The lactoferrin-DAP nanoparticles exhibited enhanced therapeutic efficacy by precisely targeting prostate cancer cells that express high lactoferrin receptors and high anti-tumor activity in vitro (at 1 μM) and in mouse prostate tumor xenografts (20 mg/kg). Mechanistically, these nanoparticles induce apoptosis in cancer cells by inducing caspase3/7 activity and disrupting the glycolytic and oxidative phosphorylation pathways. Moreover, lactoferrin-conjugated DAP nanoparticles suppressed the viability of docetaxel-resistant cells exhibiting a higher inhibitory efficacy compared to free DAP and DCA. Targeting PDK1 through lactoferrin-conjugated DAP nanoparticles represents a potent targeted therapeutic strategy for disrupting prostate tumor metabolism and offers promising implications for overcoming drug resistance.

Metabolic reprogramming of glucose: the metabolic basis for the occurrence and development of hepatocellular carcinoma

Primary liver cancer is a common malignant tumor of the digestive system, with hepatocellular carcinoma (HCC) being the most prevalent type. It is characterized by high malignancy, insidious onset, and a lack of specific early diagnostic and therapeutic markers, posing a serious threat to human health. The occurrence and development of HCC are closely related to its metabolic processes. Similar to other malignant tumors, metabolic reprogramming occurs extensively in tumor cells, with glucose metabolism reprogramming being particularly prominent. This is characterized by abnormal activation of glycolysis and inhibition of oxidative phosphorylation and gluconeogenesis, among other changes. Glucose metabolism reprogramming provides intermediates and energy for HCC to meet its demands for rapid growth, proliferation, and metastasis. Additionally, various enzymes and signaling molecules involved in glucose metabolism reprogramming play irreplaceable roles. Therefore, regulating key metabolic enzymes and pathways in these processes is considered an important target for the diagnosis and treatment of HCC. This paper reviews the current status and progress of glucose metabolism reprogramming in HCC, aiming to provide new insights for the diagnosis, detection, and comprehensive treatment strategies of HCC involving combined glucose metabolism intervention in clinical settings.

Natural Product-Based Glycolysis Inhibitors as a Therapeutic Strategy for Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitor-Resistant Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is a leading cause of cancer-related deaths worldwide. Targeted therapy against the epidermal growth factor receptor (EGFR) is a promising treatment approach for NSCLC. However, resistance to EGFR tyrosine kinase inhibitors (TKIs) remains a major challenge in its clinical management. EGFR mutation elevates the expression of hypoxia-inducible factor-1 alpha to upregulate the production of glycolytic enzymes, increasing glycolysis and tumor resistance. The inhibition of glycolysis can be a potential strategy for overcoming EGFR-TKI resistance and enhancing the effectiveness of EGFR-TKIs. In this review, we specifically explored the effectiveness of pyruvate dehydrogenase kinase inhibitors and lactate dehydrogenase A inhibitors in combating EGFR-TKI resistance. The aim was to summarize the effects of these natural products in preclinical NSCLC models to provide a comprehensive understanding of the potential therapeutic effects. The study findings suggest that natural products can be promising inhibitors of glycolytic enzymes for the treatment of EGFR-TKI-resistant NSCLC. Further investigations through preclinical and clinical studies are required to validate the efficacy of natural product-based glycolytic inhibitors as innovative therapeutic modalities for NSCLC.

Glucose metabolism disorder: a potential accomplice of SARS-CoV-2

Globally, 265,713,467 confirmed cases of SARS-CoV-2 (CoV-2), including 5,260,888 deaths, have been reported by the WHO. It is important to study the mechanism of this infectious disease. A variety of evidences show the potential association between CoV-2 and glucose metabolism. Notably, people with type 2 diabetes mellitus (T2DM) and other metabolic complications were prone to have a higher risk of developing a more severe infection course than people who were metabolically normal. The correlations between glucose metabolism and CoV-2 progression have been widely revealed. This review will discuss the association between glucose metabolism disorders and CoV-2 progression, showing the promoting effect of diabetes and other diseases related to glucose metabolism disorders on the progression of CoV-2. We will further conclude the effects of key proteins and pathways in glucose metabolism regulation on CoV-2 progression and potential interventions by targeting glucose metabolism disorders for CoV-2 treatment. Therefore, this review will provide systematic insight into the treatment of CoV-2 from the perspective of glucose metabolism.

Unraveling the Sweet Secrets of HCC: Glucometabolic Rewiring in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the primary form of liver cancer. It causes ∼ 800 000 deaths per year, which is expected to increase due to increasing rates of obesity and metabolic dysfunction associated steatotic liver disease (MASLD). Current therapies include immune checkpoint inhibitors, tyrosine kinase inhibitors, and monoclonal antibodies, but these therapies are not satisfactorily effective and often come with multiple side effects and recurrences. Metabolic reprogramming plays a significant role in HCC progression and is often conserved between tumor types. Thus, targeting rewired metabolic pathways could provide an attractive option for targeting tumor cells alone or in conjunction with existing treatments. Therefore, there is an urgent need to identify novel targets involved in cancer-mediated metabolic reprogramming in HCC. In this review, we provide an overview of molecular rewiring and metabolic reprogramming of glucose metabolism in HCC to understand better the concepts that might widen the therapeutic window against this deadly cancer.

LncRNA SNHG6 promotes glycolysis reprogramming in hepatocellular carcinoma by stabilizing the BOP1 protein

Metabolic reprogramming is an important feature in tumor progression. Long noncoding RNA's (lncRNA) small nucleolar RNA host gene 6 (SNHG6) acts as a proto-oncogene in hepatocellular carcinoma (HCC) but its role in glycolysis is mostly unknown. The role of SNHG6 and Block of proliferation 1 (BOP1) on glycolysis is assessed by glucose uptake, lactate production, oxygen consumptive rate (OCR) and extracellular acidification rate (ECAR) and glycolytic enzyme levels. The regulatory effect of SNHG6 on BOP1 protein was confirmed by Western blotting, MS2 pull-down, RNA pull-down, and RIP assay. SNHG6 and BOP1 levels were increased in HCC tissues and cells. SNHG6 and BOP1 were prognostic factors in HCC patients and significantly correlated to TP53 mutant and tumor grade. SNHG6 promoted proliferation, inhibited apoptosis, enhanced glucose uptake and lactate production, decreased OCR, and increased ECAR in HCC cell lines. SNHG6 could bind the BOP1 protein and enhance its stability. BOP1 overexpression rescued the change of proliferation, apoptosis, and glycolysis in HCCLM3 and SMMC-7721 cells. Our data indicate that SNHG6 accelerates proliferation and glycolysis and inhibits the apoptosis of HCC cell lines by binding the BOP1 protein and enhancing its stability. Both SNHG6 and BOP1 are promising prognostic and therapeutic markers in HCC.

HDAC2- and EZH2-Mediated Histone Modifications Induce PDK1 Expression through miR-148a Downregulation in Breast Cancer Progression and Adriamycin Resistance

Simple Summary

Epigenetic modification plays an important regulatory role in breast cancer progression. However, the relationship between epigenetic modification with tumor metabolism has not yet been fully elucidated. PDK1, as a key enzyme in glucose metabolism, mediates multiple tumors development. But, the mechanism of epigenetic modification in regulating PDK1 remains unclear in breast cancer. Here, we demonstrated that HDAC2 and EZH2 upregulated PDK1 expression through inhibiting miR-148a. Importantly, miR-148a targeting PDK1 regulated breast cancer cells glycolysis, invasion, epithelial-mesenchymal transition (EMT) and Adriamycin resistance. Our results suggested that the HDAC2/EZH2/miR-148a/PDK1 axis may be a promising potential therapeutic strategy.

Abstract

Background: Breast cancer has one of highest morbidity and mortality rates for women. Abnormalities regarding epigenetics modification and pyruvate dehydrogenase kinase 1 (PDK1)-induced unusual metabolism contribute to breast cancer progression and chemotherapy resistance. However, the role and mechanism of epigenetic change in regulating PDK1 in breast cancer remains to be elucidated. Methods: Gene set enrichment analysis (GSEA) and Pearson’s correlation analysis were performed to analyze the relationship between histone deacetylase 2 (HDAC2), enhancer of zeste homologue 2 (EZH2), and PDK1 in database and human breast cancer tissues. Dual luciferase reporters were used to test the regulation between PDK1 and miR-148a. HDAC2 and EZH2 were found to regulate miR-148a expression through Western blotting assays, qRT-PCR and co-immunoprecipitation assays. The effects of PDK1 and miR-148a in breast cancer were investigated by immunofluorescence (IF) assay, Transwell assay and flow cytometry assay. The roles of miR-148a/PDK1 in tumor growth were investigated in vivo. Results: We found that PDK1 expression was upregulated by epigenetic alterations mediated by HDAC2 and EZH2. At the post-transcriptional level, PDK1 was a new direct target of miR-148a and was upregulated in breast cancer cells due to miR-148a suppression. PDK1 overexpression partly reversed the biological function of miR-148a—including miR-148a’s ability to increase cell sensitivity to Adriamycin (ADR) treatment—inhibiting cell glycolysis, invasion and epithelial–mesenchymal transition (EMT), and inducing apoptosis and repressing tumor growth. Furthermore, we identified a novel mechanism: DNMT1 directly bound to EZH2 and recruited EZH2 and HDAC2 complexes to the promoter region of miR-148a, leading to miR-148a downregulation. In breast cancer tissues, HDAC2 and EZH2 protein expression levels also were inversely correlated with levels of miR-148a expression. Conclusion: Our study found a new regulatory mechanism in which EZH2 and HDAC2 mediate PDK1 upregulation by silencing miR-148a expression to regulate cancer development and Adriamycin resistance. These new findings suggest that the HDAC2/EZH2/miR-148a/PDK1 axis is a novel mechanism for regulating cancer development and is a potentially promising target for therapeutic options in the future.

Glucometabolic reprogramming: From trigger to therapeutic target in hepatocellular carcinoma

Glucose, the central macronutrient, releases energy as ATP through carbon bond oxidation and supports various physiological functions of living organisms. Hepatocarcinogenesis relies on the bioenergetic advantage conferred by glucometabolic reprogramming. The exploitation of reformed metabolism induces a uniquely inert environment conducive to survival and renders the hepatocellular carcinoma (HCC) cells the extraordinary ability to thrive even in the nutrient-poor tumor microenvironment. The rewired metabolism also confers a defensive barrier which protects the HCC cells from environmental stress and immune surveillance. Additionally, targeted interventions against key players of HCC metabolic and signaling pathways provide promising prospects for tumor therapy. The active search for novel drugs based on innovative mutation targets is warranted in the future for effectively treating advanced HCC and the preoperative downstage. This article aims to review the regulatory mechanisms and therapeutic value of glucometabolic reprogramming on the disease progression of HCC, to gain insights into basic and clinical research.

A novel AMPK activator shows therapeutic potential in hepatocellular carcinoma by suppressing HIF1α-mediated aerobic glycolysis

Hepatocellular carcinoma (HCC) is characterized by rapid growth, early vascular invasion, and high metastasis. Currently available US Food and Drug Administration (FDA)-approved drugs show low therapeutic efficacy, limiting HCC treatment to chemotherapy. We designed and synthesized a novel small molecule, SCT-1015, that allosterically activated adenosine monophosphate-activated protein kinase (AMPK) to suppress the aerobic glycolysis in HCC. SCT-1015 was shown to bind the AMPK α and β-subunit interface, thereby exposing the kinase α domain to the upstream kinases, resulting in the increased AMPK activity. SCT-1015 dramatically reduced HCC cell growth in vitro and tumor growth in vivo. We further found that AMPK formed protein complexes with hypoxia-inducible factor 1-alpha (HIF1α) and that SCT-1015-activated AMPK promoted hydroxylation of HIF1α (402P and 564P), resulting in HIF1α degradation by the ubiquitin-proteasome system. With declined HIF1α abundance, many glycolysis-related enzymes were downregulated, suppressing aerobic glycolysis, and promoting oxidative phosphorylation. These results indicated that SCT-1015 channeled HCC cells into an unfavorable metabolic status. Overall, we reported SCT-1015 as a direct activator of AMPK signaling that held therapeutic potential in HCC.