Quercetin: a silent retarder of fatty acid oxidation in breast cancer metastasis through steering of mitochondrial CPT1

The role of quercetin in modulating lipid metabolism and enhancing chemotherapy via the STAT3-CPT1B pathway in pancreatic cancer

BACKGROUND

Pancreatic cancer is a highly aggressive gastrointestinal tumor with limited treatment options, such as surgery and chemotherapy. Thus, further research into its pathogenesis and new treatments is necessary.

METHODS

Fluorescence-activated cell sorting was employed to sort pancreatic cancer stem cells (PCSCs). Sphere formation assays and Cell Counting Kit-8 (CCK-8) assays were conducted to assess stemness and proliferation capacity. Quantitative real-time PCR and Western blot analysis were employed to assess gene expression levels. Furthermore, immunofluorescence microscopy and chromatin immunoprecipitation assays were conducted to examine alterations in signaling pathways and gene expression.

RESULTS

Quercetin and gemcitabine may inhibit PANC-1 cells and PCSCs by affecting energy metabolism. Chromatin immunoprecipitation assays revealed an interaction between STAT3 and CPT1B in PCSCs. Quercetin and gemcitabine might affect energy metabolism by inhibiting STAT3 and CPT1B. Manipulating STAT3 expression (overexpression plasmids and siRNA knockdown) altered CPT1B mRNA and protein expression. Although acetyl-CoA reversed the quercetin- and gemcitabine-induced expression of N-cadherin, DECR1, and ALDH, it had minimal influence on CPT1B and STAT3 levels.

CONCLUSION

Quercetin inhibits the expression of CPT1B via the STAT3 signaling pathway, affecting lipid metabolism and exerting antitumor effects. Furthermore, the combined administration of quercetin and gemcitabine exhibits enhanced therapeutic efficacy.

Natural polyphenols as novel interventions for aging and age-related diseases: Exploring efficacy, mechanisms of action and implications for future research

Natural polyphenols are a group of components widely found in traditional Chinese medicines and have been demonstrated to delay or prevent the development of aging and age-related diseases in recent years. As far as we know, the studies of natural polyphenols in aging and aging-related diseases have never been extensively reviewed. In the present paper, we reviewed recent advances of natural polyphenols in aging and common age-related diseases and the current technological methods to improve the bioavailability of natural polyphenols. The results showed that natural polyphenols have the potential to prevent or treat aging and common age-related diseases through multiple mechanisms. Nanotechnology, structural modifications, and matrix processing could provide strong technical support for the development of natural polyphenols to prevent or treat aging and age-related diseases. In conclusion, natural polyphenols have important potential in the prevention and treatment of aging and age-related diseases.

Precision targeting of fat metabolism in triple negative breast cancer with a biotinylated copolymer

Mitochondrial CPT1-mediated fatty acid β-oxidation (FAO) critically contributes to the accelerated metastatic expansion of triple negative breast cancer (TNBC). Hence, inhibition of FAO through active CPT1 targeting could be a promising therapeutic approach in anti-TNBC therapies. Herein, we strategically synthesized a pyrene chain end labelled copolymer bearing biotin pendants, CP4, that actively targets CPT1 and efficiently blocks FAO in metastatic TNBC. Following the comprehensive characterization and synthesis of CP4, in silico negative docking score and Ramachandran plot analyses confirmed its on-target binding potential to CPT1. As a result, CP4 disrupts mitochondrial membrane potential, generates excessive ROS, and restricts excessive ATP production by impairing mitochondrial respiration, glycolytic function, and FAO. Subsequently, CP4 suppressed FA uptake and regulated FAO-associated gene expressions, exhibiting successive metastatic growth inhibition and apoptosis induction. Also, in an animal model, CP4 demonstrated active binding to CPT1, as evidenced by the significant depletion of CPT1A expression in tumor and liver tissue, akin to the specific CPT1-targeted drug. This active targeting of CPT1 has further consolidated the healing of altered lipid and oxidative stress, resulting in remarkable tumor regression, highlighting CP4 as a promising anticancer therapy focused on mitochondrial FAO, advancing future breast cancer treatments.

Metabolic Reprogramming and Adaption in Breast Cancer Progression and Metastasis

Recent evidence has revealed that cancer is not solely driven by genetic abnormalities but also by significant metabolic dysregulation. Cancer cells exhibit altered metabolic demands and rewiring of cellular metabolism to sustain their malignant characteristics. Metabolic reprogramming has emerged as a hallmark of cancer, playing a complex role in breast cancer initiation, progression, and metastasis. The different molecular subtypes of breast cancer exhibit distinct metabolic genotypes and phenotypes, offering opportunities for subtype-specific therapeutic approaches. Cancer-associated metabolic phenotypes encompass dysregulated nutrient uptake, opportunistic nutrient acquisition strategies, altered utilization of glycolysis and TCA cycle intermediates, increased nitrogen demand, metabolite-driven gene regulation, and metabolic interactions with the microenvironment. The tumor microenvironment, consisting of stromal cells, immune cells, blood vessels, and extracellular matrix components, influences metabolic adaptations through modulating nutrient availability, oxygen levels, and signaling pathways. Metastasis, the process of cancer spread, involves intricate steps that present unique metabolic challenges at each stage. Successful metastasis requires cancer cells to navigate varying nutrient and oxygen availability, endure oxidative stress, and adapt their metabolic processes accordingly. The metabolic reprogramming observed in breast cancer is regulated by oncogenes, tumor suppressor genes, and signaling pathways that integrate cellular signaling with metabolic processes. Understanding the metabolic adaptations associated with metastasis holds promise for identifying therapeutic targets to disrupt the metastatic process and improve patient outcomes. This chapter explores the metabolic alterations linked to breast cancer metastasis and highlights the potential for targeted interventions in this context.

ACSL4-mediated H3K9 and H3K27 hyperacetylation upregulates SNAIL to drive TNBC metastasis

Triple-negative breast cancer (TNBC) has profound unmet medical need globally for its devastating clinical outcome associated with rapid metastasis and lack of targeted therapies. Recently, lipid metabolic reprogramming especially fatty acid oxidation (FAO) has emerged as a major driver of breast cancer metastasis. Analyzing the expression of major FAO regulatory genes in breast cancer, we found selective overexpression of acyl-CoA synthetase 4 (ACSL4) in TNBC, which is primarily attributed to the absence of progesterone receptor. Loss of ACSL4 function, by genetic ablation or pharmacological inhibition significantly reduces metastatic potential of TNBC. Global transcriptome analysis reveals that ACSL4 activity positively influences the gene expression related to TNBC migration and invasion. Mechanistically, ACSL4 modulates FAO and intracellular acetyl-CoA levels, leading to hyperacetylation of particularly H3K9ac and H3K27ac marks resulting in overexpression of SNAIL during the course of TNBC metastatic spread to lymph node and lung. Further, human TNBC metastasis exhibits positive correlation among ACSL4, H3K9ac, H3K27ac, and SNAIL expression. Altogether, our findings provide molecular insights regarding the intricate interplay between metabolic alterations and epigenetic modifications, intertwined to orchestrate TNBC metastasis, and posit a rational understanding for the development of ACSL4 inhibitors as a targeted therapy against TNBC.

From nature to clinic: Quercetin's role in breast cancer immunomodulation

Immunotherapy has brought hope to many breast cancer patients, but not all patients benefit from it. Quercetin (Qu), a natural product found in various sources, has anti-inflammatory and anti-tumor properties. We conducted a review of the pharmacological research of Qu in regulating anti-tumor immunity in vivo and in vitro. Qu can directly regulate the local tumor microenvironment (TME) by enhancing the activity of immune cells which includes promoting the infiltration of T cells and natural killer (NK) cells, inhibiting the recruitment of myeloid-derived suppressor cells and tumor-associated macrophages. Additionally, Qu inhibits anaerobic glycolysis in tumor cells, thereby reducing the production and transport of lactic acid. It also suppresses tumor angiogenesis by targeting the vascular endothelial growth factor (VEGF) pathway and the vitamin D pathway. Furthermore, Qu can enhance the efficacy of immunotherapy for breast cancer by modulating the systemic microenvironment. This includes inhibiting obesity-related chronic inflammation to decrease the production of inflammatory factors, regulating the composition of intestinal microbiota, and intervening in the metabolism of intestinal flora. At the same time, we also address challenges in the clinical application of Qu, such as low absorption rates and unknown effective doses. In conclusion, we highlight Qu as a natural immunomodulator that enhances immune cell activity and has the potential to be developed as an adjunct for breast cancer.

Effect of quercetin and chrysin and its association on viability and cell cycle progression in MDA-MB-231 and MCF-7 human breast cancer cells

Pharmacological properties of flavonoids have been reported, with an anticancer role amongst them, however, its mechanisms are not fully elucidated. In this study, the activity of quercetin and chrysin towards MCF-7 and MDA-MB-231 breast cancer cells was investigated. Cellular viability was determined after treatment with the compounds in different concentrations for 24 h. Secondly, cells were treated with fixed concentration of chrysin and different concentrations of quercetin with preincubation for 1 h. Both compounds inhibited cellular proliferation in dose-dependent manner. The association showed improvement in their cytotoxicity, more expressively with preincubation of quercetin. Quercetin and chrysin association induced cell cycle arrest in sub-G0/G1 phase in MDA-MB-231 cells, modified the expression of caspases-3 and -8,-8, inducing late apoptosis cell death. Taken together, our results demonstrate that both flavonoids inhibited cells growth in a dose-dependent manner and the association of quercetin improved chrysin's toxic effect over the cell lines.

Loss of OVOL2 in Triple-Negative Breast Cancer Promotes Fatty Acid Oxidation Fueling Stemness Characteristics

Triple-negative breast cancer (TNBC), the most aggressive subtype of breast cancer, has a poor prognosis and lacks effective treatment strategies. Here, the study discovered that TNBC shows a decreased expression of epithelial transcription factor ovo-like 2 (OVOL2). The loss of OVOL2 promotes fatty acid oxidation (FAO), providing additional energy and NADPH to sustain stemness characteristics, including sphere-forming capacity and tumor initiation. Mechanistically, OVOL2 not only suppressed STAT3 phosphorylation by directly inhibiting JAK transcription but also recruited histone deacetylase 1 (HDAC1) to STAT3, thereby reducing the transcriptional activation of downstream genes carnitine palmitoyltransferase1 (CPT1A and CPT1B). PyVT-Ovol2 knockout mice develop a higher number of primary breast tumors with accelerated growth and increased lung-metastases. Furthermore, treatment with FAO inhibitors effectively reduces stemness characteristics of tumor cells, breast tumor initiation, and metastasis, especially in OVOL2-deficient breast tumors. The findings suggest that targeting JAK/STAT3 pathway and FAO is a promising therapeutic strategy for OVOL2-deficient TNBC.

Metabolomic Rewiring Promotes Endocrine Therapy Resistance in Breast Cancer

Approximately one-third of endocrine-treated women with estrogen receptor alpha-positive (ER+) breast cancers are at risk of recurrence due to intrinsic or acquired resistance. Thus, it is vital to understand the mechanisms underlying endocrine therapy resistance in ER+ breast cancer to improve patient treatment. Mitochondrial fatty acid β-oxidation (FAO) has been shown to be a major metabolic pathway in triple-negative breast cancer (TNBC) that can activate Src signaling. Here, we found metabolic reprogramming that increases FAO in ER+ breast cancer as a mechanism of resistance to endocrine therapy. A metabolically relevant, integrated gene signature was derived from transcriptomic, metabolomic, and lipidomic analyses in TNBC cells following inhibition of the FAO rate-limiting enzyme carnitine palmitoyl transferase 1 (CPT1), and this TNBC-derived signature was significantly associated with endocrine resistance in patients with ER+ breast cancer. Molecular, genetic, and metabolomic experiments identified activation of AMPK-FAO-oxidative phosphorylation (OXPHOS) signaling in endocrine-resistant ER+ breast cancer. CPT1 knockdown or treatment with FAO inhibitors in vitro and in vivo significantly enhanced the response of ER+ breast cancer cells to endocrine therapy. Consistent with the previous findings in TNBC, endocrine therapy-induced FAO activated the Src pathway in ER+ breast cancer. Src inhibitors suppressed the growth of endocrine-resistant tumors, and the efficacy could be further enhanced by metabolic priming with CPT1 inhibition. Collectively, this study developed and applied a TNBC-derived signature to reveal that metabolic reprogramming to FAO activates the Src pathway to drive endocrine resistance in ER+ breast cancer.

SIGNIFICANCE

Increased fatty acid oxidation induced by endocrine therapy activates Src signaling to promote endocrine resistance in breast cancer, which can be overcome using clinically approved therapies targeting FAO and Src.

Targeting dysregulated lipid metabolism in the tumor microenvironment

The reprogramming of lipid metabolism and its association with oncogenic signaling pathways within the tumor microenvironment (TME) have emerged as significant hallmarks of cancer. Lipid metabolism is defined as a complex set of molecular processes including lipid uptake, synthesis, transport, and degradation. The dysregulation of lipid metabolism is affected by enzymes and signaling molecules directly or indirectly involved in the lipid metabolic process. Regulation of lipid metabolizing enzymes has been shown to modulate cancer development and to avoid resistance to anticancer drugs in tumors and the TME. Because of this, understanding the metabolic reprogramming associated with oncogenic progression is important to develop strategies for cancer treatment. Recent advances provide insight into fundamental mechanisms and the connections between altered lipid metabolism and tumorigenesis. In this review, we explore alterations to lipid metabolism and the pivotal factors driving lipid metabolic reprogramming, which exacerbate cancer progression. We also shed light on the latest insights and current therapeutic approaches based on small molecular inhibitors and phytochemicals targeting lipid metabolism for cancer treatment. Further investigations are worthwhile to fully understand the underlying mechanisms and the correlation between altered lipid metabolism and carcinogenesis.

Phytochemicals Target Multiple Metabolic Pathways in Cancer

Cancer metabolic reprogramming is a complex process that provides malignant cells with selective advantages to grow and propagate in the hostile environment created by the immune surveillance of the human organism. This process underpins cancer proliferation, invasion, antioxidant defense, and resistance to anticancer immunity and therapeutics. Perhaps not surprisingly, metabolic rewiring is considered to be one of the "Hallmarks of cancer". Notably, this process often comprises various complementary and overlapping pathways. Today, it is well known that highly selective inhibition of only one of the pathways in a tumor cell often leads to a limited response and, subsequently, to the emergence of resistance. Therefore, to increase the overall effectiveness of antitumor drugs, it is advisable to use multitarget agents that can simultaneously suppress several key processes in the tumor cell. This review is focused on a group of plant-derived natural compounds that simultaneously target different pathways of cancer-associated metabolism, including aerobic glycolysis, respiration, glutaminolysis, one-carbon metabolism, de novo lipogenesis, and β-oxidation of fatty acids. We discuss only those compounds that display inhibitory activity against several metabolic pathways as well as a number of important signaling pathways in cancer. Information about their pharmacokinetics in animals and humans is also presented. Taken together, a number of known plant-derived compounds may target multiple metabolic and signaling pathways in various malignancies, something that bears great potential for the further improvement of antineoplastic therapy.

Selected Flavonols in Breast and Gynecological Cancer: A Systematic Review

The consumption of foods that are rich in phenolic compounds has chemopreventive effects on many cancers, including breast cancer, ovarian cancer, and endometrial cancer. A wide spectrum of their health-promoting properties such as antioxidant, anti-inflammatory, and anticancer activities, has been demonstrated. This paper analyzes the mechanisms of the anticancer action of selected common flavonols, including kemferol, myricetin, quercetin, fisetin, galangin, isorhamnetin, and morin, in preclinical studies, with particular emphasis on in vitro studies in gynecological cancers and breast cancer. In the future, these compounds may find applications in the prevention and treatment of gynecological cancers and breast cancer, but this requires further, more advanced research.

Multi-omics analysis revealed NMBA induced esophageal carcinoma tumorigenesis via regulating PPARα signaling pathway

As widespread environmental carcinogens causing esophageal carcinoma (EC), the effects of N-nitrosamines on human health hazards and accurate toxicity mechanisms have not been well-elucidated. In this study, we explored the tumorigenic mechanism of N-nitrosomethylbenzylamine (NMBA) exposure using both cell and rat models. It was found that NMBA (2 μM) exposure for 26 weeks induced malignant transformation of normal esophageal epithelial (Het-1A) cells. After then proteomics analysis showed that lipid metabolism disorder predominantly participated in the process of NMBA-induced cell malignant transformation. Further the integrated proteomics and lipidomics analysis revealed that the enhancement of fatty acid metabolism promoted the EC tumorigenesis induced by NMBA through facilitating the fatty acid-associated PPARα signaling pathway. The animal studies also revealed that accelerated fatty acid decomposition in the progression of NMBA-induced EC models of rats was accompanied by the activation of the PPARα pathway. Overall, our findings depicted the key dynamic molecular alteration triggered by N-nitrosamines, and provided comprehensive biological perspectives into the carcinogenic risk assessment of N-nitrosamines.

Molecular and Cellular Mechanisms of Propolis and Its Polyphenolic Compounds against Cancer

In recent years, interest in natural products such as alternative sources of pharmaceuticals for numerous chronic diseases, including tumors, has been renewed. Propolis, a natural product collected by honeybees, and polyphenolic/flavonoid propolis-related components modulate all steps of the cancer progression process. Anticancer activity of propolis and its compounds relies on various mechanisms: cell-cycle arrest and attenuation of cancer cells proliferation, reduction in the number of cancer stem cells, induction of apoptosis, modulation of oncogene signaling pathways, inhibition of matrix metalloproteinases, prevention of metastasis, anti-angiogenesis, anti-inflammatory effects accompanied by the modulation of the tumor microenvironment (by modifying macrophage activation and polarization), epigenetic regulation, antiviral and bactericidal activities, modulation of gut microbiota, and attenuation of chemotherapy-induced deleterious side effects. Ingredients from propolis also "sensitize" cancer cells to chemotherapeutic agents, likely by blocking the activation of the transcription factor nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). In this review, we summarize the current knowledge related to the the effects of flavonoids and other polyphenolic compounds from propolis on tumor growth and metastasizing ability, and discuss possible molecular and cellular mechanisms involved in the modulation of inflammatory pathways and cellular processes that affect survival, proliferation, invasion, angiogenesis, and metastasis of the tumor.