Biological Behavior and Lipid Metabolism of Colon Cancer Cells are Regulated by a Combination of Sterol Regulatory Element-Binding Protein 1 and ATP Citrate Lyase

Colorectal Cancer: Pathogenesis and Targeted Therapy

Colorectal cancer (CRC) ranks among the most prevalent malignant neoplasms globally. A growing body of evidence underscores the pivotal roles of genetic alterations and dysregulated epigenetic modifications in the pathogenesis of CRC. In recent years, the reprogramming of tumor cell metabolism has been increasingly acknowledged as a hallmark of cancer. Substantial evidence suggests a crosstalk between tumor cell metabolic reprogramming and epigenetic modifications, highlighting a complex interplay between metabolism and the epigenetic genome that warrants further investigation. Biomarkers associated with the pathogenesis and metabolic characteristics of CRC hold significant clinical implications. Nevertheless, elucidating the genetic, epigenetic, and metabolic landscapes of CRC continues to pose considerable challenges. Here, we attempt to summarize the key genes driving the onset and progression of CRC and the related epigenetic regulators, clarify the roles of gene expression and signaling pathways in tumor metabolism regulation, and explore the potential crosstalk between epigenetic events and tumor metabolic reprogramming, providing a comprehensive mechanistic explanation for the malignant progression of CRC. Finally, by integrating reliable targets from genetics, epigenetics, and metabolic processes that hold promise for translation into clinical practice, we aim to offer more strategies to overcome the bottlenecks in CRC treatment.

Noncanonical TCA cycle fosters canonical TCA cycle and mitochondrial integrity in acute myeloid leukemia

Cancer cells rely on mitochondrial oxidative phosphorylation (OXPHOS) and the noncanonical tricarboxylic acid (TCA) cycle. In this paper, we shed light on the vital role played by the noncanonical TCA cycle in a host-side concession to mitochondria, especially in highly energy-demanding malignant tumor cells. Inhibition of ATP-citrate lyase (ACLY), a key enzyme in the noncanonical TCA cycle, induced apoptosis by increasing reactive oxygen species levels and DNA damage while reducing mitochondrial membrane potential. The mitochondrial membrane citrate transporter inhibitor, CTPI2, synergistically enhanced these effects. ACLY inhibition reduced cytosolic citrate levels and CTPI2 lowered ACLY activity, suggesting that the noncanonical TCA cycle is sustained by a positive feedback mechanism. These inhibitions impaired ATP production, particularly through OXPHOS. Metabolomic analysis of mitochondrial and cytosolic fractions revealed reduced levels of glutathione pathway-related and TCA cycle-related metabolite, except fumarate, in mitochondria following noncanonical TCA cycle inhibition. Despite the efficient energy supply to the cell by mitochondria, this symbiosis poses challenges related to reactive oxygen species and mitochondrial maintenance. In conclusion, the noncanonical TCA cycle is indispensable for the canonical TCA cycle and mitochondrial integrity, contributing to mitochondrial domestication.

Lipid metabolism, amino acid metabolism, and prostate cancer: a crucial metabolic journey

Prostate cancer (PCa) is one of the most common malignancies in males worldwide, and its development and progression involve the regulation of multiple metabolic pathways. Alterations in lipid metabolism affect the proliferation and metastatic capabilities of PCa cells. Cancer cells increase lipid synthesis and regulate fatty acid oxidation to meet their growth and energy demands. Similarly, changes occur in amino acid metabolism in PCa. Cancer cells exhibit an increased demand for specific amino acids, and they regulate amino acid transport and metabolic pathways to fulfill their proliferation and survival requirements. These changes are closely associated with disease progression and treatment response in PCa cells. Therefore, a comprehensive investigation of the metabolic characteristics of PCa is expected to offer novel insights and approaches for the early diagnosis and treatment of this disease.

Metabolic reprogramming in cancer: Mechanisms and therapeutics

Cancer cells characterized by uncontrolled growth and proliferation require altered metabolic processes to maintain this characteristic. Metabolic reprogramming is a process mediated by various factors, including oncogenes, tumor suppressor genes, changes in growth factors, and tumor-host cell interactions, which help to meet the needs of cancer cell anabolism and promote tumor development. Metabolic reprogramming in tumor cells is dynamically variable, depending on the tumor type and microenvironment, and reprogramming involves multiple metabolic pathways. These metabolic pathways have complex mechanisms and involve the coordination of various signaling molecules, proteins, and enzymes, which increases the resistance of tumor cells to traditional antitumor therapies. With the development of cancer therapies, metabolic reprogramming has been recognized as a new therapeutic target for metabolic changes in tumor cells. Therefore, understanding how multiple metabolic pathways in cancer cells change can provide a reference for the development of new therapies for tumor treatment. Here, we systemically reviewed the metabolic changes and their alteration factors, together with the current tumor regulation treatments and other possible treatments that are still under investigation. Continuous efforts are needed to further explore the mechanism of cancer metabolism reprogramming and corresponding metabolic treatments.

Lipid metabolism reprogramming in colorectal cancer

The hallmark feature of metabolic reprogramming is now considered to be widespread in many malignancies, including colorectal cancer (CRC). Of the gastrointestinal tumors, CRC is one of the most common with a high metastasis rate and long insidious period. The incidence and mortality of CRC has increased in recent years. Metabolic reprogramming also has a significant role in the development and progression of CRC, especially lipid metabolic reprogramming. Many studies have reported that lipid metabolism reprogramming is similar to the Warburg effect with typical features affecting tumor biology including proliferation, migration, local invasion, apoptosis, and other biological behaviors of cancer cells. Therefore, studying the role of lipid metabolism in the occurrence and development of CRC will increase our understanding of its pathogenesis, invasion, metastasis, and other processes and provide new directions for the treatment of CRC. In this paper, we mainly describe the molecular mechanism of lipid metabolism reprogramming and its important role in the occurrence and development of CRC. In addition, to provide reference for subsequent research and clinical diagnosis and treatment we also review the treatments of CRC that target lipid metabolism.

Targeting SREBP-1-Mediated Lipogenesis as Potential Strategies for Cancer

Sterol regulatory element binding protein-1 (SREBP-1), a transcription factor with a basic helix–loop–helix leucine zipper, has two isoforms, SREBP-1a and SREBP-1c, derived from the same gene for regulating the genes of lipogenesis, including acetyl-CoA carboxylase, fatty acid synthase, and stearoyl-CoA desaturase. Importantly, SREBP-1 participates in metabolic reprogramming of various cancers and has been a biomarker for the prognosis or drug efficacy for the patients with cancer. In this review, we first introduced the structure, activation, and key upstream signaling pathway of SREBP-1. Then, the potential targets and molecular mechanisms of SREBP-1-regulated lipogenesis in various types of cancer, such as colorectal, prostate, breast, and hepatocellular cancer, were summarized. We also discussed potential therapies targeting the SREBP-1-regulated pathway by small molecules, natural products, or the extracts of herbs against tumor progression. This review could provide new insights in understanding advanced findings about SREBP-1-mediated lipogenesis in cancer and its potential as a target for cancer therapeutics.

Mitochondrial Sirtuins in Chronic Degenerative Diseases: New Metabolic Targets in Colorectal Cancer

Sirtuins (SIRTs) are a family of class III histone deacetylases (HDACs) consisting of seven members, widely expressed in mammals. SIRTs mainly participate in metabolic homeostasis, DNA damage repair, cell survival, and differentiation, as well as other cancer-related biological processes. Growing evidence shows that SIRTs have pivotal roles in chronic degenerative diseases, including colorectal cancer (CRC), the third most frequent malignant disease worldwide. Metabolic alterations are gaining attention in the context of CRC development and progression, with mitochondrion representing a crucial point of complex and intricate molecular mechanisms. Mitochondrial SIRTs, SIRT2, SIRT3, SIRT4 and SIRT5, control mitochondrial homeostasis and dynamics. Here, we provide a comprehensive review on the latest advances on the role of mitochondrial SIRTs in the initiation, promotion and progression of CRC. A deeper understanding of the pathways by which mitochondrial SIRTs control CRC metabolism may provide new molecular targets for future innovative strategies for CRC prevention and therapy.

Multi-Omics Analysis of Fatty Acid Metabolism in Thyroid Carcinoma

Objective

Papillary thyroid carcinoma (PTC) accounts for the majority of thyroid cancer and affects a large number of individuals. The pathogenesis of PTC has not been completely elucidated thus far. Metabolic reprogramming is a common feature in tumours. Our previous research revealed the reprogramming of lipid metabolism in PTC. Further studies on lipid metabolism reprogramming may help elucidate the pathogenesis of PTC.

Methods

Clinical samples of PTC and para-tumour tissue were analysed using lipidomic, proteomic, and metabolomic approaches. A multi-omics integrative strategy was adopted to identify the important pathways in PTC. The findings were further confirmed using western blotting, tissue microarray, bioinformatics, and cell migration assays.

Results

Multi-omics data and the results of integrated analysis revealed that the three steps of fatty acid metabolism (hydrolysis, transportation, and oxidation) were significantly enhanced in PTC. Especially, the expression levels of LPL, FATP2, and CPT1A, three key enzymes in the respective steps, were elevated in PTC. Moreover, LPL, FATP2 and CPT1A expression was associated with the TNM stage, lymph node metastasis of PTC. Moreover, high levels of FATP2 and CPT1A contributed to poor prognosis of PTC. In addition, ectopic overexpression of LPL, FATP2 and CPT1A can each promote the migration of thyroid cancer cells.

Conclusions

Our data suggested that enhanced fatty acid metabolism supplied additional energy and substrates for PTC progression. This may help elucidating the underlying mechanism of PTC pathogenesis and identifying the potential therapeutic targets for PTC.

SIRT3 and Metabolic Reprogramming Mediate the Antiproliferative Effects of Whey in Human Colon Cancer Cells

Emerging strategies to improve healthy aging include dietary interventions as a tool to promote health benefits and reduce the incidence of aging-related comorbidities. The health benefits of milk are also linked to its richness in betaines and short-chain acylcarnitines, which act synergistically in conferring anticancer, anti-inflammatory, and antioxidant properties. Whey, despite being a dairy by-product, still has a considerable content of bioactive betaines and acylcarnitines. Here, we investigated the anticancer properties of whey from Mediterranean water buffalo (Bubalus bubalis) milk by testing its antiproliferative effects in colorectal cancer (CRC) cells HT-29, HCT 116, LoVo and SW480. Results indicated that treatment with whey for 72 h inhibited cell proliferation (p < 0.001), induced cell cycle arrest, and apoptosis via caspase-3 activation, and modulated cell metabolism by limiting glucose uptake and interfering with mitochondrial energy metabolism with the highest effects observed in HT-29 and HCT 116 cells. At molecular level, these effects were accompanied by upregulation of sirtuin 3 (SIRT3) (p < 0.01) and peroxisome proliferator-activated receptor (PPAR)-γ expression (p < 0.001), and downregulation of lactate dehydrogenase A (LDHA) (p < 0.01), sterol regulatory-element binding protein 1 (SREBP1) (p < 0.05), and PPAR-α (p < 0.01). Transient SIRT3 gene silencing blocked the effects of whey on the LDHA, PPAR-γ, and PPAR-α protein expressions (p < 0.01) suggesting that the whey capacity of perturbating the metabolic homeostasis in CRC cell lines is mediated by SIRT3.