ABSTRACT
INTRODUCTION: Excessive visceral adiposity is known to drive the onset of metabolic derangements, mostly involving oxidative stress, prolonged inflammation, and cellular senescence. N-acetylcysteine (NAC) is a synthetic form of
Subject(s)
Acetylcysteine , Cellular Senescence , Cyclin-Dependent Kinase Inhibitor p21 , Interleukin-6 , Intra-Abdominal Fat , Obesity , Tumor Necrosis Factor-alpha , beta-Galactosidase , Humans , Acetylcysteine/pharmacology , Intra-Abdominal Fat/metabolism , Intra-Abdominal Fat/drug effects , Cellular Senescence/drug effects , Adult , Male , beta-Galactosidase/metabolism , Interleukin-6/metabolism , Tumor Necrosis Factor-alpha/metabolism , Female , Obesity/metabolism , Obesity/drug therapy , Cyclin-Dependent Kinase Inhibitor p21/metabolism , Cyclin-Dependent Kinase Inhibitor p21/genetics , Cyclin-Dependent Kinase Inhibitor p16/metabolism , Middle Aged , Tumor Suppressor Protein p53/metabolism , Antioxidants/pharmacology , Antioxidants/metabolism , Oxidative Stress/drug effects , Inflammation/metabolismABSTRACT
Obesity, which is the accumulation of fat in adipose tissue, has adverse impacts on human health. Obesity-related metabolic dysregulation has similarities to the metabolic alterations observed in aging. It has been shown that the adipocytes of obese individuals undergo cellular aging, known as senescence. Senescence can be transmitted to other normal cells through a series of chemical factors referred to as the senescence-associated secretory phenotype (SASP). Most of these factors are pro-inflammatory compounds. The immune system removes these senescent T-cells, but immunosenescence, which is the senescence of immune cells, disrupts the clearance of senescent T-cells. Immunosenescence occurs as a result of aging or indirectly through transmission from senescent tissues. The significant occurrence of senescence in obesity is expected to cause immunosenescence and impairs the immune response to resolve inflammation. The sustained and chronic inflammation disrupts insulin's metabolic actions in metabolic tissues. Therefore, this review focuses on the role of senescent adipocyte cells in obesity-associated immunosenescence and subsequent metabolic dysregulation. Moreover, the article suggests novel therapeutic approaches to improve metabolic syndrome by targeting senescent T-cells or using senotherapeutics.
ABSTRACT
People with cancer often experience long-term physical and psychological stress, which can have a significant impact on tumor metabolism and treatment. The effects of adrenergic signaling on metabolic pathways are well known, but only a few studies have looked into the connection between this signaling and tumor metabolism. This study examined the effects of treatment with isoproterenol (Iso) alone and in combination with ß-hydroxybutyrate (ßHB), a mitochondrial fuel, on the metabolism, survival, and migration of SW480 colon cancer cells treated with 5-fluorouracil (5FU). The researchers measured the oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) to determine the metabolic profile of these cells. They also analyzed the gene expression of PGC-1α, c-MYC, and NANOG to investigate the relationship between metabolic phenotype and stemness status. Scratch assays were used to assess cell migration. The results showed that Iso treatment increased cell viability in both SW480 and 5FU-treated SW480 cells. There was a significant decrease in ECAR and an increase in OCR after Iso treatment in both cell types. The expression of c-MYC and NANOG, genes associated with stemness, increased, while the expression of PGC-1α, a gene related to oxidative phosphorylation, decreased following Iso treatment. Iso treatment also increased the migration potential of both SW480 and 5FU-treated SW480 cells. These findings suggest that under stressful conditions, 5FU-treated colon cancer cells can utilize the oxidative phosphorylation pathway for growth and migration.
ABSTRACT
OBJECTIVE: The effect of thyroid hormone (TH) on cancers was proposed more than 100 years ago; however, conclusions are conflicting. THs are precisely regulated at tissue and cellular levels. It seems that this regulation is altered in cancers. Thyroid hormone receptor beta (TRß) has anti-proliferative and tumor-suppressive effects in many cancer cells. Therefore, we decided to investigate thyroid hormone receptor beta (THRB) expression and activation by the selective agonist, GC-1, on tumor growth in a syngeneic mouse model of colorectal cancer (CRC) and colon cell lines. METHODS: In vitro cell viability assay using MTT analysis, cell cycle analysis by PI staining, and FACS analysis were performed. In vivo tumor growth measurements were carried out by caliper and [18F] Fluoro-2-deoxy-2-D-glucose (FDG) - PET imaging. Gene expressions were determined using quantitative-PCR. RESULTS: Some concentrations of GC-1 had a marked negative effect on the cell viability of colorectal cell lines. Cell cycle analysis showed that the anti-proliferative effect of GC-1 may not result from cell cycle arrest or apoptosis. Tumor growth analysis in mice harboring colorectal tumor showed that GC-1 treatment for 8 d profoundly inhibited tumor growth and 18FDG uptake. THRB expression was decreased in mice tumor; however, it was upregulated following GC-1 administration. CONCLUSIONS: Our results showed that specific activation of TRß by GC-1 had negative effect on tumor growth and restored its gene expression in tumors of CRC mice model.
Subject(s)
Colorectal Neoplasms , Thyroid Hormone Receptors beta , Acetates , Animals , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/genetics , Disease Models, Animal , Fluorodeoxyglucose F18 , Glucose , Mice , Phenols , Thyroid Hormone Receptors beta/genetics , Thyroid Hormone Receptors beta/metabolism , Thyroid HormonesABSTRACT
Background: Beta-hydroxybutyrate (BHB) as a ketone body is the metabolic fuel in oxidative phosphorylation pathway. So far the effects of BHB on the biology of tumor cells is contradictory. Therefore, we investigated the effect of BHB on viability, metabolism, proliferation and migration of 5FU treated SW480 colon cancer cell line. Methods: we treated the SW480 cells with IC50 dose of 5-fluorouracil (5FU) for 72 h to isolate a subpopulation of 5FU treated cells that were resistant to it. Effects of BHB on cell viability was investigated by MTT assay. Measurement of oxygen consumption rate (OCR) in parallel with extracellular acidification rate (ECAR) upon BHB treatment was used for determination of metabolic profile of these cells. Investigating the relationship between metabolic phenotype and the status of differentiation and stemness was done by analyzing the expression of PGC-1α, c-MYC, NANOG, ALPi and KRT20 genes by qRT-PCR. Clonogenic and scratch assay were performed to determine the proliferation and migration abilities of incubated with BHB compared to untreated cells. Results: BHB increased cell viability in SW480 and 5FU treated SW480 cells. The results showed a significantly decreased ECAR and increased OCR in both cell types following BHB treatment reflecting the superiority of oxidative phosphorylation profile compared to glycolysis in both cell types. Also, treatment with BHB increases the expression of genes normally associated with stemness and mitochondrial biogenesis and decreases the expression of genes related to glycolytic program and differentiation in 5FU treated cells. Self-renewal and migration potential of BHB treated cells increased significantly. Conclusion: These findings suggest that BHB utilization via oxidative mitochondrial metabolism can fuel proliferation, migration and stemness in 5FU treated SW480 colon cancer cells.