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1.
Cancer Metastasis Rev ; 43(1): 115-133, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37768439

ABSTRACT

B7-H3 (B7 homology 3 protein) is an important transmembrane immunoregulatory protein expressed in immune cells, antigen-presenting cells, and tumor cells. Studies reveal a multifaceted role of B7-H3 in tumor progression by modulating various cancer hallmarks involving angiogenesis, immune evasion, and tumor microenvironment, and it is also a promising candidate for cancer immunotherapy. In colorectal cancer (CRC), B7-H3 has been associated with various aspects of disease progression, such as evasion of tumor immune surveillance, tumor-node metastasis, and poor prognosis. Strategies to block or interfere with B7-H3 in its immunological and non-immunological functions are under investigation. In this study, we explore the role of B7-H3 in tumor plasticity, emphasizing tumor glucose metabolism, angiogenesis, epithelial-mesenchymal transition, cancer stem cells, apoptosis, and changing immune signatures in the tumor immune landscape. We discuss how B7-H3-induced tumor plasticity contributes to immune evasion, metastasis, and therapy resistance. Furthermore, we delve into the most recent advancements in targeting B7-H3-based tumor immunotherapy as a potential approach to CRC treatment.


Subject(s)
B7 Antigens , Colorectal Neoplasms , Humans , B7 Antigens/metabolism , Colorectal Neoplasms/pathology , Immunotherapy , Tumor Microenvironment
2.
Brain ; 146(6): 2389-2398, 2023 06 01.
Article in English | MEDLINE | ID: mdl-36415957

ABSTRACT

More than half of adults with epilepsy undergoing resective epilepsy surgery achieve long-term seizure freedom and might consider withdrawing antiseizure medications. We aimed to identify predictors of seizure recurrence after starting postoperative antiseizure medication withdrawal and develop and validate predictive models. We performed an international multicentre observational cohort study in nine tertiary epilepsy referral centres. We included 850 adults who started antiseizure medication withdrawal following resective epilepsy surgery and were free of seizures other than focal non-motor aware seizures before starting antiseizure medication withdrawal. We developed a model predicting recurrent seizures, other than focal non-motor aware seizures, using Cox proportional hazards regression in a derivation cohort (n = 231). Independent predictors of seizure recurrence, other than focal non-motor aware seizures, following the start of antiseizure medication withdrawal were focal non-motor aware seizures after surgery and before withdrawal [adjusted hazard ratio (aHR) 5.5, 95% confidence interval (CI) 2.7-11.1], history of focal to bilateral tonic-clonic seizures before surgery (aHR 1.6, 95% CI 0.9-2.8), time from surgery to the start of antiseizure medication withdrawal (aHR 0.9, 95% CI 0.8-0.9) and number of antiseizure medications at time of surgery (aHR 1.2, 95% CI 0.9-1.6). Model discrimination showed a concordance statistic of 0.67 (95% CI 0.63-0.71) in the external validation cohorts (n = 500). A secondary model predicting recurrence of any seizures (including focal non-motor aware seizures) was developed and validated in a subgroup that did not have focal non-motor aware seizures before withdrawal (n = 639), showing a concordance statistic of 0.68 (95% CI 0.64-0.72). Calibration plots indicated high agreement of predicted and observed outcomes for both models. We show that simple algorithms, available as graphical nomograms and online tools (predictepilepsy.github.io), can provide probabilities of seizure outcomes after starting postoperative antiseizure medication withdrawal. These multicentre-validated models may assist clinicians when discussing antiseizure medication withdrawal after surgery with their patients.


Subject(s)
Epilepsies, Partial , Epilepsy, Generalized , Epilepsy , Humans , Adult , Anticonvulsants/adverse effects , Neoplasm Recurrence, Local/drug therapy , Epilepsy/drug therapy , Epilepsy/surgery , Seizures/drug therapy , Epilepsy, Generalized/drug therapy
3.
PLoS Pathog ; 17(6): e1009634, 2021 06.
Article in English | MEDLINE | ID: mdl-34157054

ABSTRACT

Coronavirus Disease 2019 (COVID-19), caused by a new strain of coronavirus called Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), was declared a pandemic by WHO on March 11, 2020. Soon after its emergence in late December 2019, it was noticed that diabetic individuals were at an increased risk of COVID-19-associated complications, ICU admissions, and mortality. Maintaining proper blood glucose levels using insulin and/or other oral antidiabetic drugs (such as Metformin) reduced the detrimental effects of COVID-19. Interestingly, in diabetic COVID-19 patients, while insulin administration was associated with adverse outcomes, Metformin treatment was correlated with a significant reduction in disease severity and mortality rates among affected individuals. Metformin was extensively studied for its antioxidant, anti-inflammatory, immunomodulatory, and antiviral capabilities that would explain its ability to confer cardiopulmonary and vascular protection in COVID-19. Here, we describe the various possible molecular mechanisms that contribute to Metformin therapy's beneficial effects and lay out the scientific basis of repurposing Metformin for use in COVID-19 patients.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Antiviral Agents/therapeutic use , COVID-19 Drug Treatment , Diabetes Complications/drug therapy , Metformin/therapeutic use , Animals , COVID-19/complications , Drug Repositioning , Humans
4.
Int J Mol Sci ; 20(12)2019 Jun 20.
Article in English | MEDLINE | ID: mdl-31226817

ABSTRACT

Calcium (Ca2+) signaling and the modulation of intracellular calcium ([Ca2+]i) levels play critical roles in several key processes that regulate cellular survival, growth, differentiation, metabolism, and death in normal cells. On the other hand, aberrant Ca2+-signaling and loss of [Ca2+]i homeostasis contributes to tumor initiation proliferation, angiogenesis, and other key processes that support tumor progression in several different cancers. Currently, chemically and functionally distinct drugs are used as chemotherapeutic agents in the treatment and management of cancer among which certain anti-cancer drugs reportedly suppress pro-survival signals and activate pro-apoptotic signaling through modulation of Ca2+-signaling-dependent mechanisms. Most importantly, the modulation of [Ca2+]i levels via the endoplasmic reticulum-mitochondrial axis and corresponding action of channels and pumps within the plasma membrane play an important role in the survival and death of cancer cells. The endoplasmic reticulum-mitochondrial axis is of prime importance when considering Ca2+-signaling-dependent anti-cancer drug targets. This review discusses how calcium signaling is targeted by anti-cancer drugs and highlights the role of calcium signaling in epigenetic modification and the Warburg effect in tumorigenesis.


Subject(s)
Antineoplastic Agents/pharmacology , Calcium Signaling/drug effects , Cell Proliferation/drug effects , Neoplasms/drug therapy , Animals , Antineoplastic Agents/therapeutic use , Apoptosis/drug effects , Calcium/metabolism , Endoplasmic Reticulum/drug effects , Endoplasmic Reticulum/metabolism , Humans , Mitochondria/drug effects , Mitochondria/metabolism , Molecular Targeted Therapy/methods , Neoplasms/metabolism
5.
Cereb Cortex ; 27(7): 3675-3682, 2017 07 01.
Article in English | MEDLINE | ID: mdl-27436130

ABSTRACT

In recent years there has been a significant commercial interest in 'brain training' - massed or spaced practice on a small set of tasks to boost cognitive performance. Recently, researchers have combined cognitive training regimes with brain stimulation to try and maximize training benefits, leading to task-specific cognitive enhancement. It remains unclear, however, whether the performance gains afforded by such regimes can transfer to untrained tasks, or how training and stimulation affect the brain's latent information processing dynamics. To examine these issues, we applied transcranial direct current stimulation (tDCS) over the prefrontal cortex while participants undertook decision-making training over several days. Anodal, relative to cathodal/sham tDCS, increased performance gains from training. Critically, these gains were reliable for both trained and untrained tasks. The benefit of anodal tDCS occurred for left, but not right, prefrontal stimulation, and was absent for stimulation delivered without concurrent training. Modeling revealed left anodal stimulation combined with training caused an increase in the brain's rate of evidence accumulation for both tasks. Thus tDCS applied during training has the potential to modulate training gains and give rise to transferable performance benefits for distinct cognitive operations through an increase in the rate at which the brain acquires information.


Subject(s)
Attention/physiology , Cognition/physiology , Decision Making/physiology , Prefrontal Cortex/physiology , Teaching , Transcranial Direct Current Stimulation/methods , Acoustic Stimulation , Adult , Female , Functional Laterality , Humans , Male , Random Allocation , Young Adult
6.
Apoptosis ; 22(7): 898-919, 2017 07.
Article in English | MEDLINE | ID: mdl-28424988

ABSTRACT

Inhibitors of apoptosis (IAPs) are a family of proteins that play a significant role in the control of programmed cell death (PCD). PCD is essential to maintain healthy cell turnover within tissue but also to fight disease or infection. Uninhibited, IAPs can suppress apoptosis and promote cell cycle progression. Therefore, it is unsurprising that cancer cells demonstrate significantly elevated expression levels of IAPs, resulting in improved cell survival, enhanced tumor growth and subsequent metastasis. Therapies to target IAPs in cancer has garnered substantial scientific interest and as resistance to anti-cancer agents becomes more prevalent, targeting IAPs has become an increasingly attractive strategy to re-sensitize cancer cells to chemotherapies, antibody based-therapies and TRAIL therapy. Antagonism strategies to modulate the actions of XIAP, cIAP1/2 and survivin are the central focus of current research and this review highlights advances within this field with particular emphasis upon the development and specificity of second mitochondria-derived activator of caspase (SMAC) mimetics (synthetic analogs of endogenously expressed inhibitors of IAPs SMAC/DIABLO). While we highlight the potential of SMAC mimetics as effective single agent or combinatory therapies to treat cancer we also discuss the likely clinical implications of resistance to SMAC mimetic therapy, occasionally observed in cancer cell lines.


Subject(s)
Apoptosis/genetics , Inhibitor of Apoptosis Proteins/genetics , Intracellular Signaling Peptides and Proteins/genetics , Mitochondrial Proteins/genetics , Neoplasms/drug therapy , Apoptosis/drug effects , Apoptosis Regulatory Proteins , Drug Resistance, Neoplasm/genetics , Humans , Inhibitor of Apoptosis Proteins/antagonists & inhibitors , Intracellular Signaling Peptides and Proteins/antagonists & inhibitors , Mitochondrial Proteins/antagonists & inhibitors , Neoplasms/genetics , Neoplasms/pathology , Survivin , TNF-Related Apoptosis-Inducing Ligand/genetics , X-Linked Inhibitor of Apoptosis Protein/genetics
7.
Indian J Community Med ; 49(1): 96-103, 2024.
Article in English | MEDLINE | ID: mdl-38425947

ABSTRACT

Background: COVID-19 has become a global pandemic, prompting lockdowns in practically every country. To prevent the spread of the disease, India has enforced a rigorous nationwide lockdown that commenced in March 2020. The lockdown imposed amid the pandemic ensured that most commercial activities and vehicle transportation ceased, resulting in a significant reduction in air pollution levels. Material and Methods: The value of air pollutants PM10, PM2.5, NO2, and SO2 from January to May 2020 was obtained from the Indian Central Pollution Control Board. Before lockdown and during lockdown, relative fluctuations in ambient concentrations of four air contaminants were investigated. The Box-Jenkins approach was used to estimate future air pollution data points using time series data analysis. Results: The PM10 level reduced by 61%, 30%, 68%, 37%, and 43% in the selected cities, respectively. Comparison of other pollutant concentrations before and after the lockdown also found a reduction in ambient pollutant concentrations, resulting in improved air quality. Inference of predicted model values to observed values revealed a significant increase in the concentrations of all pollutants. The percentage increases in AQImean from predicted to observed values were 206% in Ghaziabad, 148% in Delhi, 59% in Hyderabad, and 160% in Cochin. Conclusion: The strict lockdown has resulted in a significant drop in air pollutant levels. Upgrading present technologies could help keep pollution to a minimum of 37% under control. The findings would prompt the government to consider how to strictly reduce vehicle and industrial pollution to improve air quality and maintain improved public health.

8.
Indian J Exp Biol ; 51(11): 1012-7, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24416939

ABSTRACT

Production of fuel ethanol from lignocellulosic biomass conventionally includes biomass pretreatment, hydrolysis, and fermentation. The liquor generated during dilute acid pretreatment of biomass contains considerable quantities of pentose sugars as well as various degradation products of sugars and lignin, like furfural, hydroxymethyl furfural (HMF), organic acids, aldehydes and others, which are known to be inhibitory for microbial growth. This pentose rich liquor is a potent resource which can be used to produce alcohol or other value added metabolites by microbial fermentation. However, the presence of these inhibitory compounds is a major hindrance and their removal is essential for efficient utilization of this byproduct stream. In the present work, the polymeric adsorbent resins, XAD-4, XAD-7 and XAD-16 were evaluated for their ability to adsorb fermentation inhibitors like furfural and HMF from the acid pretreated liquor. These resins could remove 55-75% of furfural and 100% of HMF and more than 90% sugar remained un-adsorbed in the pretreated liquor. Desorption of furfural from stationary phase was evaluated by using ethanol and hot water. The results suggest that these polymeric resins may be used for detoxification of acid pretreatment liquor with selective removal of sugar degradation products without affecting the sugar content in the solution.


Subject(s)
Acids/chemistry , Biomass , Lignin/chemistry , Polymers/chemistry , Adsorption , Fermentation , Lignin/metabolism
9.
Biomed Pharmacother ; 164: 114911, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37224753

ABSTRACT

Breast cancers (BCs) remain the leading cause of cancer-related deaths among women worldwide. Among the different types of BCs, treating the highly aggressive, invasive, and metastatic triple-negative BCs (TNBCs) that do not respond to hormonal/human epidermal growth factor receptor 2 (HER2) targeted interventions since they lack ER/PR/HER2 receptors remains challenging. While almost all BCs depend on glucose metabolism for their proliferation and survival, studies indicate that TNBCs are highly dependent on glucose metabolism compared to non-TNBC malignancies. Hence, limiting/inhibiting glucose metabolism in TNBCs should curb cell proliferation and tumor growth. Previous reports, including ours, have shown the efficacy of metformin, the most widely prescribed antidiabetic drug, in reducing cell proliferation and growth in MDA-MB-231 and MDA-MB-468 TNBC cells. In the current study, we investigated and compared the anticancer effects of either metformin (2 mM) in glucose-starved or 2-deoxyglucose (10 mM; glycolytic inhibitor; 2DG) exposed MDA-MB-231 and MDA-MB-468 TNBC cells. Assays for cell proliferation, rate of glycolysis, cell viability, and cell-cycle analysis were performed. The status of proteins of the mTOR pathway was assessed by Western blot analysis. Metformin treatment in glucose-starved and 2DG (10 mM) exposed TNBC cells inhibited the mTOR pathway compared to non-treated glucose-starved cells or 2DG/metformin alone treated controls. Cell proliferation is also significantly reduced under these combination treatment conditions. The results indicate that combining a glycolytic inhibitor and metformin could prove an efficient therapeutic approach for treating TNBCs, albeit the efficacy of the combination treatment may depend on metabolic heterogeneity across various subtypes of TNBCs.


Subject(s)
Metformin , Triple Negative Breast Neoplasms , Female , Humans , Metformin/pharmacology , Metformin/therapeutic use , Deoxyglucose/pharmacology , Triple Negative Breast Neoplasms/pathology , Cell Line, Tumor , Cell Proliferation , TOR Serine-Threonine Kinases , Glucose/metabolism
10.
Amyloid ; 30(2): 141-152, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36286264

ABSTRACT

BACKGROUND: The amyloidogenic transthyretin (TTR) variant, V122I, occurs in 4% of the African American population and frequently presents as a restricted cardiomyopathy. While heterozygosity for TTR V122I predominates, several compound heterozygous cases have been previously described. Herein, we detail features of ATTRv amyloidosis associated with novel compound heterozygous TTR mutation, T60I/V122I and provide evidence supporting the amyloidogenecity of T60I. METHODS: A 63-year-old African American female presented with atrial fibrillation, congestive heart failure, autonomic and peripheral neuropathy. In vitro studies of TTR T60I and V122I were undertaken to compare the biophysical properties of the proteins. RESULTS: Congophilic deposits in a rectal biopsy were immunohistochemically positive for TTR. Serum screening by isoelectric focussing revealed two TTR variants in the absence of wild-type protein. DNA sequencing identified compound heterozygous TTR gene mutations, c.239C > T and c.424G > A. Adipose amyloid deposits were composed of both T60I and V122I. While kinetic stabilities of T60I and V122I variants were similar, distinct thermodynamic stabilities and amyloid growth kinetics were observed. CONCLUSIONS: This report provides clinical and experimental results supporting the amyloidogenic nature of a novel TTR T60I variant. In vitro data indicate that the destabilising effect of individual T60I and V122I variants appears to be additive rather than synergistic.


Subject(s)
Amyloid Neuropathies, Familial , Amyloidosis , Heart Failure , Peripheral Nervous System Diseases , Humans , Female , Middle Aged , Amyloidosis/metabolism , Heart Failure/genetics , Amyloid/metabolism , Heterozygote , Peripheral Nervous System Diseases/complications , Prealbumin/genetics , Prealbumin/metabolism , Amyloid Neuropathies, Familial/genetics
11.
Biomolecules ; 12(11)2022 10 28.
Article in English | MEDLINE | ID: mdl-36358930

ABSTRACT

It is a well-accepted fact that obesity and diabetes increase the risk of incidence of different cancers and their progression, leading to a decrease in the quality of life among affected cancer patients. In addition to decreasing the risk of cancers, maintaining a healthy body mass index (BMI)/body weight and/or blood glucose levels within the normal range critically impacts the response to anti-cancer therapy among affected individuals. A cancer patient managing their body weight and maintaining blood glucose control responds better to anti-cancer therapy than obese individuals and those whose blood glucose levels remain higher than normal during therapeutic intervention. In some cases, anti-diabetic/glucose-lowering drugs, some of which are also used to promote weight loss, were found to possess anti-cancer potential themselves and/or support anti-cancer therapy when used to treat such patients. On the other hand, certain glucose-lowering drugs promoted the cancer phenotype and risked cancer progression when used for treatment. Tirzepatide (TRZD), the glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide/gastric inhibitory peptide (GIP) agonist, has recently gained interest as a promising injectable drug for the treatment of type 2 diabetes and was approved by the FDA after successful clinical trials (SURPASS 1/2/3/4 and 5, NCT03954834, NCT03987919, NCT03882970, NCT03730662, and NCT04039503). In addition, the reports from the SURMOUNT-1 clinical trial (NCT04184622) support the use of TRZD as an anti-obesity drug. In the current review article, we examine the possibility and molecular mechanisms of how TRZD intervention could benefit cancer therapeutics or increase the risk of cancer progression when used as an anti-diabetic drug in diabetic patients.


Subject(s)
Diabetes Mellitus, Type 2 , Neoplasms , Humans , Blood Glucose , Quality of Life , Weight Loss , Obesity/complications , Obesity/drug therapy , Glucose , Neoplasms/drug therapy
12.
Vaccines (Basel) ; 10(3)2022 Mar 16.
Article in English | MEDLINE | ID: mdl-35335086

ABSTRACT

The COVID-19 vaccines currently in use have undoubtedly played the most significant role in combating the SARS-CoV-2 virus and reducing disease severity and the risk of death among those affected, especially among those with pre-existing conditions, such as diabetes. The management of blood glucose levels has become critical in the context of the COVID-19 pandemic, where data show two- to threefold higher intensive care hospital admissions and more than twice the mortality rate among diabetic COVID-19 patients when compared with their nondiabetic counterparts. Furthermore, new-onset diabetes and severe hyperglycemia-related complications, such as hyperosmolar hyperglycemic syndrome (HHS) and diabetic ketoacidosis (DKA), were reported in COVID-19 patients. However, irrespective of the kind of vaccine and dosage number, possible vaccination-induced hyperglycemia and associated complications were reported among vaccinated individuals. The current article summarizes the available case reports on COVID-19 vaccination-induced hyperglycemia, the possible molecular mechanism responsible for this phenomenon, and the outstanding questions that need to be addressed and discusses the need to identify at-risk individuals and promote postvaccination monitoring/surveillance among at-risk individuals.

13.
Trends Microbiol ; 29(10): 894-907, 2021 10.
Article in English | MEDLINE | ID: mdl-33785249

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections present with increased disease severity and poor clinical outcomes in diabetic patients compared with their nondiabetic counterparts. Diabetes/hyperglycemia-triggered endothelial dysfunction and hyperactive inflammatory and immune responses are correlated to twofold to threefold higher intensive care hospitalizations and more than twice the mortality among diabetic coronavirus disease 2019 (COVID-19) patients. While comorbidities such as obesity, cardiovascular disease, and hypertension worsen the prognosis of diabetic COVID-19 patients, COVID-19 infections are also associated with new-onset diabetes, severe metabolic complications, and increased thrombotic events in the backdrop of aberrant endothelial function. While several antidiabetic medications are used to manage blood glucose levels, we discuss the multifaceted ability of metformin to control blood glucose levels and possibly attenuate endothelial dysfunction, inhibit viral entry and infection, and modify inflammatory and immune responses during SARS-CoV-2 infections. These actions make metformin a viable candidate drug to be considered for repurposing and gaining ground against the SARS-CoV-2-induced tsunami in diabetic COVID-19 patients.


Subject(s)
COVID-19/complications , Diabetes Mellitus/drug therapy , Hypoglycemic Agents/administration & dosage , Metformin/administration & dosage , Animals , Blood Glucose/metabolism , COVID-19/metabolism , COVID-19/virology , Diabetes Mellitus/metabolism , Drug Repositioning , Humans , SARS-CoV-2/drug effects , SARS-CoV-2/genetics , SARS-CoV-2/physiology
14.
Cancers (Basel) ; 13(2)2021 Jan 07.
Article in English | MEDLINE | ID: mdl-33430318

ABSTRACT

Tumor cells develop several metabolic reprogramming strategies, such as increased glucose uptake and utilization via aerobic glycolysis and fermentation of glucose to lactate; these lead to a low pH environment in which the cancer cells thrive and evade apoptosis. These characteristics of tumor cells are known as the Warburg effect. Adaptive metabolic alterations in cancer cells can be attributed to mutations in key metabolic enzymes and transcription factors. The features of the Warburg phenotype may serve as promising markers for the early detection and treatment of tumors. Besides, the glycolytic process of tumors is reversible and could represent a therapeutic target. So-called mono-target therapies are often unsafe and ineffective, and have a high prevalence of recurrence. Their success is hindered by the ability of tumor cells to simultaneously develop multiple chemoresistance pathways. Therefore, agents that modify several cellular targets, such as energy restriction to target tumor cells specifically, have therapeutic potential. Resveratrol, a natural active polyphenol found in grapes and red wine and used in many traditional medicines, is known for its ability to target multiple components of signaling pathways in tumors, leading to the suppression of cell proliferation, activation of apoptosis, and regression in tumor growth. Here, we describe current knowledge on the various mechanisms by which resveratrol modulates glucose metabolism, its potential as an imitator of caloric restriction, and its therapeutic capacity in tumors.

15.
Cancers (Basel) ; 13(12)2021 Jun 16.
Article in English | MEDLINE | ID: mdl-34208645

ABSTRACT

Metabolic reprogramming characterized by alterations in nutrient uptake and critical molecular pathways associated with cancer cell metabolism represents a fundamental process of malignant transformation. Melatonin (N-acetyl-5-methoxytryptamine) is a hormone secreted by the pineal gland. Melatonin primarily regulates circadian rhythms but also exerts anti-inflammatory, anti-depressant, antioxidant and anti-tumor activities. Concerning cancer metabolism, melatonin displays significant anticancer effects via the regulation of key components of aerobic glycolysis, gluconeogenesis, the pentose phosphate pathway (PPP) and lipid metabolism. Melatonin treatment affects glucose transporter (GLUT) expression, glucose-6-phosphate dehydrogenase (G6PDH) activity, lactate production and other metabolic contributors. Moreover, melatonin modulates critical players in cancer development, such as HIF-1 and p53. Taken together, melatonin has notable anti-cancer effects at malignancy initiation, progression and metastasing. Further investigations of melatonin impacts relevant for cancer metabolism are expected to create innovative approaches supportive for the effective prevention and targeted therapy of cancers.

16.
Article in English | MEDLINE | ID: mdl-33364523

ABSTRACT

The circadian clock, which generates the internal daily rhythm largely mediated through release of melatonin, can be disrupted in various ways. Multiple factors result in a disruption of the circadian cycle in the clinical context, of interest are anti-cancer drugs such as cisplatin. Cisplatin modulates the circadian clock through two mechanisms: 1) the circadian clock control of DNA excision repair and 2) the effect of circadian clock disruption on apoptosis. Cisplatin can stimulate multiple classified molecules, including DNA repair factors, DNA damage recognition factors and transcription factors in drug resistance and cisplatin-induced signal transduction. These factors interact with each other and can be transformed by DNA damage. Hence, these molecular interactions are intimately involved in cell proliferation and damage-induced apoptosis. Cisplatin has a dual-effect on circadian genes: upregulation of CLOCK expression causes an increase in proliferation but upregulation of BMAL1 expression causes an increase in apoptosis. Therefore, the interference of circadian genes by cisplatin can have multiple, opposing effects on apoptosis and cell proliferation, which may have unintended pro-cancer effects. Melatonin and intracellular Ca2+ also have a dual-effect on cell proliferation and apoptosis and can disrupt circadian rhythms.

17.
Cancers (Basel) ; 12(8)2020 Aug 12.
Article in English | MEDLINE | ID: mdl-32806533

ABSTRACT

Breast cancer (BC) is the most prevalent cancer in women. BC is heterogeneous, with distinct phenotypical and morphological characteristics. These are based on their gene expression profiles, which divide BC into different subtypes, among which the triple-negative breast cancer (TNBC) subtype is the most aggressive one. The growing interest in tumor metabolism emphasizes the role of altered glucose metabolism in driving cancer progression, response to cancer treatment, and its distinct role in therapy resistance. Alterations in glucose metabolism are characterized by increased uptake of glucose, hyperactivated glycolysis, decreased oxidative phosphorylation (OXPHOS) component, and the accumulation of lactate. These deviations are attributed to the upregulation of key glycolytic enzymes and transporters of the glucose metabolic pathway. Key glycolytic enzymes such as hexokinase, lactate dehydrogenase, and enolase are upregulated, thereby conferring resistance towards drugs such as cisplatin, paclitaxel, tamoxifen, and doxorubicin. Besides, drug efflux and detoxification are two energy-dependent mechanisms contributing to resistance. The emergence of resistance to chemotherapy can occur at an early or later stage of the treatment, thus limiting the success and outcome of the therapy. Therefore, understanding the aberrant glucose metabolism in tumors and its link in conferring therapy resistance is essential. Using combinatory treatment with metabolic inhibitors, for example, 2-deoxy-D-glucose (2-DG) and metformin, showed promising results in countering therapy resistance. Newer drug designs such as drugs conjugated to sugars or peptides that utilize the enhanced expression of tumor cell glucose transporters offer selective and efficient drug delivery to cancer cells with less toxicity to healthy cells. Last but not least, naturally occurring compounds of plants defined as phytochemicals manifest a promising approach for the eradication of cancer cells via suppression of essential enzymes or other compartments associated with glycolysis. Their benefits for human health open new opportunities in therapeutic intervention, either alone or in combination with chemotherapeutic drugs. Importantly, phytochemicals as efficacious instruments of anticancer therapy can suppress events leading to chemoresistance of cancer cells. Here, we review the current knowledge of altered glucose metabolism in contributing to resistance to classical anticancer drugs in BC treatment and various ways to target the aberrant metabolism that will serve as a promising strategy for chemosensitizing tumors and overcoming resistance in BC.

18.
Biomolecules ; 10(2)2020 01 27.
Article in English | MEDLINE | ID: mdl-32012744

ABSTRACT

Several phytochemicals have been identified for their role in modifying miRNA regulating tumor progression. miRNAs modulate the expression of several oncogenes and tumor suppressor genes including the genes that regulate tumor angiogenesis. Hypoxia inducible factor-1 alpha (HIF-1α) signaling is a central axis that activates oncogenic signaling and acts as a metabolic switch in endothelial cell (EC) driven tumor angiogenesis. Tumor angiogenesis driven by metabolic reprogramming of EC is crucial for tumor progression and metastasis in many different cancers, including breast cancers, and has been linked to aberrant miRNA expression profiles. In the current article, we identify different miRNAs that regulate tumor angiogenesis in the context of oncogenic signaling and metabolic reprogramming in ECs and review how selected phytochemicals could modulate miRNA levels to induce an anti-angiogenic action in breast cancer. Studies involving genistein, epigallocatechin gallate (EGCG) and resveratrol demonstrate the regulation of miRNA-21, miRNA-221/222 and miRNA-27, which are prognostic markers in triple negative breast cancers (TNBCs). Modulating the metabolic pathway is a novel strategy for controlling tumor angiogenesis and tumor growth. Cardamonin, curcumin and resveratrol exhibit their anti-angiogenic property by targeting the miRNAs that regulate EC metabolism. Here we suggest that using phytochemicals to target miRNAs, which in turn suppresses tumor angiogenesis, should have the potential to inhibit tumor growth, progression, invasion and metastasis and may be developed into an effective therapeutic strategy for the treatment of many different cancers where tumor angiogenesis plays a significant role in tumor growth and progression.


Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Breast Neoplasms/drug therapy , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , MicroRNAs/metabolism , Neovascularization, Pathologic , Angiogenesis Inhibitors/pharmacology , Breast Neoplasms/metabolism , Chalcones/pharmacology , Curcumin/pharmacology , Disease Progression , Endothelial Cells/metabolism , Female , Humans , Neoplasm Invasiveness , Neoplasm Metastasis , Oxygen/metabolism , Phytochemicals , Phytotherapy , Prognosis , Reactive Oxygen Species/metabolism , Resveratrol/pharmacology , Signal Transduction
19.
Cancers (Basel) ; 12(9)2020 Sep 01.
Article in English | MEDLINE | ID: mdl-32883003

ABSTRACT

Despite the leaps and bounds in achieving success in the management and treatment of breast cancers through surgery, chemotherapy, and radiotherapy, breast cancer remains the most frequently occurring cancer in women and the most common cause of cancer-related deaths among women. Systemic therapeutic approaches, such as chemotherapy, although beneficial in treating and curing breast cancer subjects with localized breast tumors, tend to fail in metastatic cases of the disease due to (a) an acquired resistance to the chemotherapeutic drug and (b) the development of intrinsic resistance to therapy. The existence of cancer stem cells (CSCs) plays a crucial role in both acquired and intrinsic chemoresistance. CSCs are less abundant than terminally differentiated cancer cells and confer chemoresistance through a unique altered metabolism and capability to evade the immune response system. Furthermore, CSCs possess active DNA repair systems, transporters that support multidrug resistance (MDR), advanced detoxification processes, and the ability to self-renew and differentiate into tumor progenitor cells, thereby supporting cancer invasion, metastasis, and recurrence/relapse. Hence, current research is focusing on targeting CSCs to overcome resistance and improve the efficacy of the treatment and management of breast cancer. Studies revealed that metformin (1, 1-dimethylbiguanide), a widely used anti-hyperglycemic agent, sensitizes tumor response to various chemotherapeutic drugs. Metformin selectively targets CSCs and improves the hypoxic microenvironment, suppresses the tumor metastasis and inflammation, as well as regulates the metabolic programming, induces apoptosis, and reverses epithelial-mesenchymal transition and MDR. Here, we discuss cancer (breast cancer) and chemoresistance, the molecular mechanisms of chemoresistance in breast cancers, and metformin as a chemo-sensitizing/re-sensitizing agent, with a particular focus on breast CSCs as a critical contributing factor to acquired and intrinsic chemoresistance. The review outlines the prospects and directions for a better understanding and re-purposing of metformin as an anti-cancer/chemo-sensitizing drug in the treatment of breast cancer. It intends to provide a rationale for the use of metformin as a combinatory therapy in a clinical setting.

20.
Cancers (Basel) ; 12(9)2020 Aug 26.
Article in English | MEDLINE | ID: mdl-32859058

ABSTRACT

An incidence and mortality of cancer are rapidly growing worldwide, especially due to heterogeneous character of the disease that is associated with irreversible impairment of cellular homeostasis and function. Targeting apoptosis, one of cancer hallmarks, represents a potent cancer treatment strategy. Carotenoids are phytochemicals represented by carotenes, xanthophylls, and derived compounds such as apocarotenoids that demonstrate a broad spectrum of anti-cancer effects involving pro-apoptotic signaling through extrinsic and intrinsic pathways. As demonstrated in preclinical oncology research, the apoptotic modulation is performed at post-genomic levels. Further, carotenoids demonstrate additive/synergistic action in combination with conventional oncostatic agents. In addition, a sensitization of tumor cells to anti-cancer conventional treatment can be achieved by carotenoids. The disadvantage of anti-cancer application of carotenoids is associated with their low solubility and, therefore, poor bioavailability. However, this deficiency can be improved by using nanotechnological approaches, solid dispersions, microemulsions or biofortification that significantly increase the anti-cancer and pro-apoptotic efficacy of carotenoids. Only limited number of studies dealing with apoptotic potential of carotenoids has been published in clinical sphere. Pro-apoptotic effects of carotenoids should be beneficial for individuals at high risk of cancer development. The article considers the utility of carotenoids in the framework of 3P medicine.

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