Browsing by Author "Mantha, Anil K."

Now showing 1 - 20 of 46

Anticancer activity of dihydropyrazolo [1, 5‐c] quinazolines against rat C6 glioma cells via inhibition of topoisomerase II
(wiley, 2018) Kaur, G; Cholia, Raman Preet; Joshi, G; Amrutkar, S.M; Kalra, S; Mantha, Anil K.; Banerjee, U.C; Kumar, R.
The design and synthesis of dihydropyrazolo[1,5‐c]quinazolines (1a–h) as human topoisomerase II (TopoII) catalytic inhibitors are reported. The compounds were investigated for their antiproliferative activity against the C6 rat glial cell line. Two compounds, 1b and 1h, were found to be potent cytotoxic agents against glioma cells and exerted selective TopoII inhibitory activity. Furthermore, the compounds induced alterations in reactive oxygen species levels as measured by DCFDA assay and were found to induce cell cycle arrest at the G1 phase at lower concentrations and profound apoptosis at higher concentrations. The interaction of selected investigational molecules with TopoII was further corroborated by molecular modeling
Anticancer activity of dihydropyrazolo[1,5-c]quinazolines against rat C6 glioma cells via inhibition of topoisomerase II.
(Wiley, 2018) Kaur, G; Cholia, RP; Joshi, G; Amrutkar, SM; Kalra, S; Mantha, Anil K.; Banerjee, UC; Kumar, R.
The design and synthesis of dihydropyrazolo[1,5‐c]quinazolines (1a–h) as human topoisomerase II (TopoII) catalytic inhibitors are reported. The compounds were investigated for their antiproliferative activity against the C6 rat glial cell line. Two compounds, 1b and 1h, were found to be potent cytotoxic agents against glioma cells and exerted selective TopoII inhibitory activity. Furthermore, the compounds induced alterations in reactive oxygen species levels as measured by DCFDA assay and were found to induce cell cycle arrest at the G1 phase at lower concentrations and profound apoptosis at higher concentrations. The interaction of selected investigational molecules with TopoII was further corroborated by molecular modeling.
Anticancer activity of dihydropyrazolo[1,5-c]quinazolines against rat C6 glioma cells via inhibition of topoisomerase II
(Wiley-VCH Verlag, 2018) Kaur, G.; Cholia, R.P.; Joshi, G.; Amrutkar, S.M.; Kalra, S.; Mantha, Anil K.; Banerjee, U.C.; Kumar, Raj
The design and synthesis of dihydropyrazolo[1,5-c]quinazolines (1a?h) as human topoisomerase II (TopoII) catalytic inhibitors are reported. The compounds were investigated for their antiproliferative activity against the C6 rat glial cell line. Two compounds, 1b and 1h, were found to be potent cytotoxic agents against glioma cells and exerted selective TopoII inhibitory activity. Furthermore, the compounds induced alterations in reactive oxygen species levels as measured by DCFDA assay and were found to induce cell cycle arrest at the G1 phase at lower concentrations and profound apoptosis at higher concentrations. The interaction of selected investigational molecules with TopoII was further corroborated by molecular modeling. ? 2018 Deutsche Pharmazeutische Gesellschaft
APE1 modulates cellular responses to organophosphate pesticide-induced oxidative damage in non-small cell lung carcinoma A549 cells
(Springer New York LLC, 2018) Thakur, Shweta; Dhiman, Monisha; Mantha, Anil K.
Monocrotophos (MCP) and chlorpyrifos (CP) are widely used organophosphate pesticides (OPPs), speculated to be linked with human pathologies including cancer. Owing to the fact that lung cells are most vulnerable to the environmental toxins, the development and progression of lung cancer can be caused by the exposure of OPPs. The present study investigates the oxidative DNA damage response evoked by MCP and CP in human non-small cell lung carcinoma A549 cells. A549 cells were exposed to MCP and CP; cytotoxicity and reactive oxygen species (ROS) generation were measured to select the non-toxic dose. In order to establish whether MCP and CP can initiate the DNA repair and cell survival signalling pathways in A549 cells, qRT-PCR and Western blotting techniques were used to investigate the mRNA and protein expression levels of DNA base excision repair (BER)-pathway enzymes and transcription factors (TFs) involved in cell survival mechanisms. A significant increase in cell viability and ROS generation was observed when exposed to low and moderate doses of MCP and CP at different time points (24, 48 and 72?h) studied. A549 cells displayed a dose-dependent accumulation of apurinic/apyrimidinic (AP) sites after 24?h exposure to MCP advocating for the activation of AP endonuclease-mediated DNA BER-pathway. Cellular responses to MCP- and CP-induced oxidative stress resulted in an imbalance in the mRNA and protein expression of BER-pathway enzymes, viz. PARP1, OGG1, APE1, XRCC1, DNA pol ? and DNA ligase III ? at different time points. The treatment of OPPs resulted in the upregulation of TFs, viz. Nrf2, c-jun, phospho-c-jun and inducible nitric oxide synthase. Immunofluorescent confocal imaging of A549 cells indicated that MCP and CP induces the translocation of APE1 within the cytoplasm at an early 6?h time point, whereas it promotes nuclear localization after 24?h of treatment, which suggests that APE1 subcellular distribution is dynamically regulated in response to OPP-induced oxidative stress. Furthermore, nuclear colocalization of APE1 and the TF c-jun was observed in response to the treatment of CP and MCP for different time points in A549 cells. Therefore, in this study we demonstrate that MCP- and CP-induced oxidative stress alters APE1-dependent BER-pathway and also mediates cell survival signalling mechanisms via APE1 regulation, thereby promoting lung cancer cell survival and proliferation. ? 2017, Springer Science+Business Media, LLC.
APE1/Ref-1 as an emerging therapeutic target for various human diseases: Phytochemical modulation of its functions
(Nature Publishing Group, 2014) Thakur, Shweta; Sarkar, Bibekananda; Cholia, Ravi P.; Gautam, Nandini; Dhiman, Monisha; Mantha, Anil K.
Apurinic/apyrimidinic endonuclease 1 (APE1) is a multifunctional enzyme involved in the base excision repair (BER) pathway, which repairs oxidative base damage caused by endogenous and exogenous agents. APE1 acts as a reductive activator of many transcription factors (TFs) and has also been named redox effector factor 1, Ref-1. For example, APE1 activates activator protein-1, nuclear factor kappa B, hypoxia-inducible factor 1a, paired box gene 8, signal transducer activator of transcription 3 and p53, which are involved in apoptosis, inflammation, angiogenesis and survival pathways. APE1/Ref-1 maintains cellular homeostasis (redox) via the activation of TFs that regulate various physiological processes and that crosstalk with redox balancing agents (for example, thioredoxin, catalase and superoxide dismutase) by controlling levels of reactive oxygen and nitrogen species. The efficiency of APE1/Ref-1's function(s) depends on pairwise interaction with participant protein(s), the functions regulated by APE1/Ref-1 include the BER pathway, TFs, energy metabolism, cytoskeletal elements and stress-dependent responses. Thus, APE1/Ref-1 acts as a 'hub-protein' that controls pathways that are important for cell survival. In this review, we will discuss APE1/Ref-1's versatile nature in various human etiologies, including neurodegeneration, cancer, cardiovascular and other diseases that have been linked with alterations in the expression, subcellular localization and activities of APE/Ref-1. APE1/Ref-1 can be targeted for therapeutic intervention using natural plant products that modulate the expression and functions of APE1/Ref-1. In addition, studies focusing on translational applications based on APE1/Ref-1-mediated therapeutic interventions are discussed. ? 2014 KSBMB.
APE1: A Molecule of Focus with Neuroprotective and Anti-Cancer Properties
(OMICS Publishing Group, 2013) Mantha, Anil K.
Apurinic/Apyrimidinic endonuclease (APE1) is a multi-functional, central enzyme of base excision repair (BER) pathway that takes care of oxidized base damage (AP sites and strand breaks) caused by both endogenous and exogenous oxidative DNA damaging agents. In repair function, APE1 exhibits majorly abasic (AP) endonuclease activity and stable interaction(s) with BER-pathway participant proteins. Second function of APE1 is redox activation of various transcription factors (TFs e.g., c-jun, NF-kB, p53 and HIF1α) and also named as redox effector factor 1(Ref-1). In redox function, APE1 reductively activates TFs involved in regulation of gene expression for cell survival mechanisms through stable pair-wise interaction(s). Recent studies have indicated that APE1 also possesses other distinct functions such as RNA metabolism, riboendonuclease activity and protein-protein interaction for maintaining cellular homeostasis. Altered APE1 expression has been reported in various cancers and neurodegenerative diseases. Taken together such findings advocates the necessity to delineate the underlying molecular mechanism(s) for understanding its role in various biological functions, that could be translated to its application in therapeutics against human diseases like cancer, neurodegenerative diseases and other pathologies such as cardiovascular diseases.
Assessment of antioxidant potential of phytochemicals in human glioblastoma (U-87 MG) cells
(Central University of Punjab, 2014) Kaur, Manpreet; Mantha, Anil K.
Imbalance between production of reactive oxygen/nitrogen species (ROS/RNS) leads to oxidative stress and has been well documented for mitochondrial dysfunction, a prime cause towards pathogenesis of neurological diseases and cancer. Glioblastoma Multiforme (GBM) is a highly aggressive, invasive and primary brain tumor which shows resistance to chemotherapy and radiotherapy. Superoxide dismutase (SOD) is an antioxidant enzyme that scavenges the production of superoxide radicals and dismutases into H?O? which is further converted into H?O and O? by catalase (CAT) enzyme. Apurinic/Apyrimidinic endonuclease (APE1) is a central enzyme of base excision repair (BER) pathway with two important functions; DNA repair and redox regulation of transcription factors (TFs) responsible for cell survival. In this study, it was seen that oxidative stress induced by endogenously found oxidants H?O? and glucose oxidase (GO) enhanced the activities of both CuZn-SOD and MnSOD in U-87 MG cells. In addition, CuZn-SOD levels were found to be increased in H?O?-induced oxidative stress and MnSOD levels were found to be increased in both H?O? and GO- induced oxidative stress. Further, pretreatment with phytochemicals Curcumin and Quercetin modulated the activities and expression of both forms of SOD studied. The BER-pathway enzyme, APE1 level was found to be decreased in mitochondria of oxidative stress induced U-87 MG cells by H?O? and GO, and in contrast APE1 level was found to be increased in cytosol, which indicates that oxidative stress affects the expression level and sub-cellular localization of APE1. Taken together, these results indicate that in GBM it is more likely that activated SOD a key player of antioxidant system and APE1 a key player in BER-pathway might be facilitating cancer cells to survive in oxidative stress environment.
Biodegradable nanoparticulate co-delivery of flavonoid and doxorubicin: Mechanistic exploration and evaluation of anticancer effect in vitro and in vivo
(Elsevier Ltd, 2021-07-30T00:00:00) Khan, Iliyas; Sarkar, Bibekananda; Joshi, Gaurav; Nakhate, Kartik T.; Ajazuddin; Mantha, Anil K.; Kumar, Raj; Kaul, Ankur; Chaturvedi, Shubhra; Mishra, Anil K.; Gupta, Umesh
The proposed study involves delivering drug/bioactive using a single nanoplatform based on poly lactic-co-glycolic acid (PLGA) for better efficacy, synergistic effect, and reduced toxicity. PLGA was conjugated to doxorubicin (D1), and this conjugate was used for encapsulation of naringenin (D2) to develop naringenin loaded PLGA-doxorubicin nanoparticles (PDNG). The PDNG NPs were 165.4 � 4.27 nm in size, having 0.112 � 0.035 PDI, with -10.1 � 2.74 zeta potential. The surface morphology was confirmed through transmission electron microscopy (TEM) and atomic force microscopy (AFM). The in vitro studies revealed that PDNG NPs exhibited selective anticancer potential in breast cancer cells, and induced apoptosis with S-phase inhibition via an increase in intrinsic reactive oxygen species (ROS) and altering the mitochondrial potential. The results also signified the efficient uptake of nanoparticles encapsulated drugs by cells besides elevating the caspase level suggesting programmed cell death induction upon treatment. In vivo studies results revealed better half-life (27.35 � 1.58 and 11.98 � 1.21 h for doxorubicin and naringenin) with higher plasma drug concentration. In vivo biodistribution study was also in accordance with the in vitro studies and in line with the in vivo pharmacokinetic. In vivo tumor regression assay portrayed that the formulation PDNG halts the tumor growth and lessen the tumor volume with the stable bodyweight of the mice. Conclusively, the dual delivery approach was beneficial and highly effective against tumor-induced mice. � 2021 The Author(s)
Bioremediation: A favorable perspective to eliminate heavy metals from polluted soil
(Elsevier, 2022-09-30T00:00:00) Kaur, Sukhchain; Midha, Tushar; Verma, Harkomal; Muduli, Rasmi Ranjan; Dutta, Oyindril; Saini, Omprakash; Prakash, Richa; Sharma, Sandeep; Mantha, Anil K.; Dhiman, Monisha
The heavy metal contamination in the environment causes serious risk and long-term lethal effects to all living organisms due to their ability to show toxicity at low concentrations. The bio-magnification of heavy metals in the food chain is a matter of concern for public health. The persistent exposure to heavy metals such as mercury (Hg), lead (Pb), cadmium (Cd), arsenic (As), and uranium (U) cause several pathologic conditions in humans by interfering with normal cellular processes. Due to the non-biodegradable nature of these pollutants, they get accumulated for a long time in the soil. The removal of these pollutants by conventional methods is not satisfactory due to the high cost and generation of huge quantities of waste products. Hence, the use of micro-organisms is the most successful approach to remediate heavy metals from the environment due to their efficacy and financial viability. Numerous microorganisms have been employed to diminish the toxic effects of heavy metals. The combination of microorganisms and plants as a bioremediation strategy is another efficient method for heavy metal bioremediation. The chapter will summarize the heavy metal exploitation with a focus on Cd, As, Pb, and Chromium (Cr). It will also describe the various bioremediation techniques which are being used in the removal of these heavy metals from soil. � 2023 Elsevier Inc. All rights reserved.
Biosensors for breast cancer diagnosis: A review of bioreceptors, biotransducers and signal amplification strategies
(Elsevier Ltd, 2017) Mittal, Sunil; Kaur, Hardeep; Gautam, Nandini; Mantha, Anil K.
Breast cancer is highly prevalent in females and accounts for second highest number of deaths, worldwide. Cumbersome, expensive and time consuming detection techniques presently available for detection of breast cancer potentiates the need for development of novel, specific and ultrasensitive devices. Biosensors are the promising and selective detection devices which hold immense potential as point of care (POC) tools. Present review comprehensively scrutinizes various breast cancer biosensors developed so far and their technical evaluation with respect to efficiency and potency of selected bioreceptors and biotransducers. Use of glycoproteins, DNA biomarkers, micro-RNA, circulatory tumor cells (CTC) and some potential biomarkers are introduced briefly. The review also discusses various strategies used in signal amplification such as nanomaterials, redox mediators, p19 protein, duplex specific nucleases (DSN) and redox cycling. ? 2016 Elsevier B.V.
Brain Exosomes: Friend or Foe in Alzheimer�s Disease?
(Springer, 2021-09-30T00:00:00) Kaur, Sharanjot; Verma, Harkomal; Dhiman, Monisha; Tell, Gianluca; Gigli, Gian Luigi; Janes, Francesco; Mantha, Anil K.
Alzheimer�s disease (AD) is the most common neurodegenerative disease. It is known to be a multifactorial disease and several causes are associated with its occurrence as well as progression. However, the accumulation of amyloid beta (A?) is widely considered its major pathogenic hallmark. Additionally, neurofibrillary tangles (NFT), mitochondrial dysfunction, oxidative stress, and aging (cellular senescence) are considered as additional hits affecting the disease pathology. Several studies are now suggesting important role of inflammation in AD, which shifts our thought towards the brain�s resident immune cells, microglia, and astrocytes; how they interact with neurons; and how these interactions are affected by intra and extracellular stressful factors. These interactions can be modulated by different mechanisms and pathways, in which exosomes could play an important role. Exosomes are multivesicular bodies secreted by nearly all types of cells. The exosomes secreted by glial cells or neurons affect the interactions and thus the physiology of these cells by transmitting miRNAs, proteins, and lipids. Exosomes can serve as a friend or foe to the neuron function, depending upon the carried signals. Exosomes, from the healthy microenvironment, may assist neuron function and health, whereas, from the stressed microenvironment, they carry oxidative and inflammatory signals to the neurons and thus prove detrimental to the neuronal function. Furthermore, exosomes can cross the blood�brain barrier (BBB), and from the blood plasma they can enter the brain cells and activate microglia and astrocytes. Exosomes can transport A? or Tau, cytokines, miRNAs between the cells, and alter the physiology of recipient cells. They can also assist in A? clearance and regulation of synaptic activity. The exosomes derived from different cells play different roles, and this field is still in its infancy stage. This review advocates exosomes� role as a friend or foe in neurodegenerative diseases, especially in the case of Alzheimer�s disease. � 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
Brain Exosomes: Friend or Foe in Alzheimer�s Disease?
(Springer, 2021-09-30T00:00:00) Kaur, Sharanjot; Verma, Harkomal; Dhiman, Monisha; Tell, Gianluca; Gigli, Gian Luigi; Janes, Francesco; Mantha, Anil K.
Alzheimer�s disease (AD) is the most common neurodegenerative disease. It is known to be a multifactorial disease and several causes are associated with its occurrence as well as progression. However, the accumulation of amyloid beta (A?) is widely considered its major pathogenic hallmark. Additionally, neurofibrillary tangles (NFT), mitochondrial dysfunction, oxidative stress, and aging (cellular senescence) are considered as additional hits affecting the disease pathology. Several studies are now suggesting important role of inflammation in AD, which shifts our thought towards the brain�s resident immune cells, microglia, and astrocytes; how they interact with neurons; and how these interactions are affected by intra and extracellular stressful factors. These interactions can be modulated by different mechanisms and pathways, in which exosomes could play an important role. Exosomes are multivesicular bodies secreted by nearly all types of cells. The exosomes secreted by glial cells or neurons affect the interactions and thus the physiology of these cells by transmitting miRNAs, proteins, and lipids. Exosomes can serve as a friend or foe to the neuron function, depending upon the carried signals. Exosomes, from the healthy microenvironment, may assist neuron function and health, whereas, from the stressed microenvironment, they carry oxidative and inflammatory signals to the neurons and thus prove detrimental to the neuronal function. Furthermore, exosomes can cross the blood�brain barrier (BBB), and from the blood plasma they can enter the brain cells and activate microglia and astrocytes. Exosomes can transport A? or Tau, cytokines, miRNAs between the cells, and alter the physiology of recipient cells. They can also assist in A? clearance and regulation of synaptic activity. The exosomes derived from different cells play different roles, and this field is still in its infancy stage. This review advocates exosomes� role as a friend or foe in neurodegenerative diseases, especially in the case of Alzheimer�s disease. � 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
Common geometric basis for apurinic/apyrimidinic endonuclease catalytic activity in structurally non-homologous APE1 and Endonuclease IV.
(2013) Tsutakawa, S.E.; Shin, D.S.; Mol, C.D.; Izumi, T.; Arvai, A.S.; Mantha, Anil K.; Szczesny, B.; Ivanov, I.N.; Hosfield, D.J.; Frankel, K.A.; Hitomi, K; Cunningham, R. P.; Tainer, J. A.
Connecting the Link between Oxidative Stress, Dietary Antioxidants and Hypertension
(CRC Press, 2023-06-12T00:00:00) Kaur, Sukhchain; Midha, Tushar; Dutta, Oyndril; Saini, Om Prakash; Muduli, Rasmi Ranjan; Mantha, Anil K.; Dhiman, Monisha
Cardiovascular disorders such as hypertension, coronary heart disease (CHD), cerebrovascular disease, etc. accounts for millions of deaths per year and among these, hypertension (i.e. increased blood pressure) acts as a silent killer and is responsible for 7.5 billion deaths worldwide. Previously, abnormal functioning of the Renin Angiotensin Aldosterone System (RAAS) was considered as a risk factor for hypertension but in recent times, oxidative stress is a key factor in exaggerating the disease progression. In hypertension, oxidative stress damages the biomolecules, decreases the NO availability and endothelial functioning. The use of external antioxidants as therapeutic agents is an excellent approach in the treatment of hypertension. These antioxidants can reverse the deleterious effects of oxidative stress and recover normal cellular homeostasis. The book chapter is focused on the various natural antioxidants and their role as anti-hypertensive agents. � 2024 selection and editorial matter, Victor R. Preedy, Vinood B. Patel, and Rajkumar Rajendram.
Conserved structural chemistry for incision activity in structurally non-homologous apurinic/apyrimidinic endonuclease APE1 and endonuclease IV DNA repair enzymes
(2013) Tsutakawa, Susan E.; Shin, David S.; Mol, Clifford D.; Lzumi, Tadahide; Arwai, Andrew S.; Mantha, Anil K.; Szczesny, Bartosz; Ivanov, Ivaylo N.; Hosfield, David J.; Maiti, Buddhadev; Pique, Mike E.; Frankel, Kenneth A.; Hitomi. Kenichi; Cunnigham, Richard, P.; Mitra, Sankar; Tainer, John A.
Non-coding apurinic/apyrimidinic (AP) sites in DNA form spontaneously and as DNA base excision repair intermediates are the most common toxic and mutagenic in vivo DNA lesion. For repair,APsites must be processed by 5' AP endonucleases in initial stages of base repair. Human APE1 and bacterial Nfo represent the two conserved 5' AP endonuclease families in the biosphere; they both recognize AP sites and incise the phosphodiester backbone 5' to the lesion, yet they lack similar structures and metal ion requirements. Here, we determined and analyzed crystal structures of a 2.4 ? resolution APE1-DNA product complex with Mg2+ and a 0.92 ? Nfo with three metal ions. Structural and biochemical comparisons of these two evolutionarily distinct enzymes characterize keyAPE1catalytic residues that are potentially functionally similar to Nfo active site components, as further tested and supported by computational analyses. We observe a magnesium-water cluster in the APE1 active site, with only Glu-96 forming the direct protein coordination to the Mg2+. Despite differences in structure and metal requirements of APE1 and Nfo, comparison of their active site structures surprisingly reveals strong geometric conservation of the catalytic reaction, with APE1 catalytic side chains positioned analogously to Nfo metal positions, suggesting surprising functional equivalence between Nfo metal ions and APE1 residues. The finding that APE1 residues are positioned to substitute for Nfo metal ions is supported by the impact of mutations on activity. Collectively, the results illuminate the activities of residues, metal ions, and active site features for abasic site endonucleases.
Curcumin revitalizes Amyloid beta (25–35)-induced and organophosphate pesticides pestered neurotoxicity in SH-SY5Y and IMR-32 cells via activation of APE1 and Nrf2
(Springer, 2017) Sarkar, Bibekananda; Dhiman, Monisha; Mittal, Sunil; Mantha, Anil K.
Amyloid beta (Aβ) peptide deposition is the primary cause of neurodegeneration in Alzheimer’s disease (AD) pathogenesis. Several reports point towards the role of pesticides in the AD pathogenesis, especially organophosphate pesticides (OPPs). Monocrotophos (MCP) and Chlorpyrifos (CP) are the most widely used OPPs. In this study, the role of MCP and CP in augmenting the Aβ-induced oxidative stress associated with the neurodegeneration in AD has been assessed in human neuroblastoma IMR-32 and SH-SY5Y cell lines. From the cell survival assay, it was observed that MCP and CP reduced cell survival both dose- and time-dependently. Nitro blue tetrazolium (NBT) based assay for determination of intracellular reactive oxygen species (ROS) demonstrated that Aβ(25–35), MCP or CP produce significant oxidative stress alone or synergistically in IMR-32 and SH-SY5Y cells, while pretreatment of curcumin reduced ROS levels significantly in all treatment combinations. In this study, we also demonstrate that treatment of Aβ(25–35) and MCP upregulated inducible nitric oxide synthase (iNOS/NOS2) whereas, no change was observed in neuronal nitric oxide synthase (nNOS/NOS1), but down-regulation of the nuclear factor erythroid 2-related factor 2 (Nrf2) level was observed. While curcumin pretreatment resulted in upregulation of iNOS and Nrf2 proteins. Also, the expression of key DNA repair enzymes APE1, DNA polymerase beta (Pol β), and PARP1 were found to be downregulated upon treatment with MCP, Aβ(25–35) and their combinations at 24 h and 48 h time points. In this study, pretreatment of curcumin to the SH-SY5Y cells enhanced the expression of DNA repair enzymes APE1, pol β, and PARP1 enzymes to counter the oxidative DNA base damage via base excision repair (BER) pathway, and also activated the antioxidant element (ARE) via Nrf2 upregulation. Furthermore, the immunofluorescent confocal imaging studies in SH-SY5Y and IMR-32 cells treated with Aβ(25–35) and MCP-mediated oxidative stress and their combinations at different time periods suggesting for cross-talk between the two proteins APE1 and Nrf2. The APE1’s association with Nrf2 might be associated with the redox function of APE1 that might be directly regulating the ARE-mediated neuronal survival mechanisms.
DNA Repair and Redox Activities and Inhibitors of Apurinic/ Apyrimidinic Endonuclease 1/Redox Effector Factor 1 (APE1/Ref-1): A Comparative Analysis and Their Scope and Limitations toward Anticancer Drug Development
(ACS Publications, 2014) Kaur, Gagandeep; Cholia, Ravi P.; Mantha, Anil K.; Kumar, Raj
The apurinic/apyrimidinic endonuclease 1/redox effector factor 1 (APE1/Ref-1) is a multifunctional enzyme involved in DNA repair and activation of transcription factors through its redox function. The evolutionarily conserved C- and N-termini are involved in these functions independently. It is also reported that the activity of APE1/Ref-1 abruptly increases several-fold in various human cancers. The control over the outcomes of these two functions is emerging as a new strategy to combine enhanced DNA damage and chemotherapy in order to tackle the major hurdle of increased cancer cell growth and proliferation. Studies have targeted these two domains individually for the design and development of inhibitors for APE1/Ref-1. Here, we have made, for the first time, an attempt at a comparative analysis of APE1/Ref-1 inhibitors that target both DNA repair and redox activities simultaneously. We further discuss their scope and limitations with respect to the development of potential anticancer agents.
Effect of amyloid beta (25-35) peptide on mitochondrial respiratiory function in neuroral cells over expressing ape1
(Central University of Punjab, 2014) Kaur, Navrattam; Mantha, Anil K.
Alzheimer's disease (AD) is an important public health problem which affects millions of people worldwide. The major pathological hallmarks associated with AD are the accumulation of amyloid beta (A?) in senile plaques and neurofibrillary tangles (NFTs) made up of hyperphosphorylated tau proteins. Accumulating evidences point towards the role of oxidative stress and mitochondrial dysfunction in the pathogenesis of AD. Aging is considered as one of the greatest risk factor for AD. In order to maintain genome integrity, base excision repair (BER) pathway is the predominant pathway for repairing oxidized base lesions in neuronal cells. APE1 is the central enzyme of the BER-pathway, having both repair and redox activities and shown to enhance neuronal survival after oxidative stress. In my study, effect of A?(25-35) on mitochondrial ROS/RNS levels and activities of respiratory complexes (I, III, & IV) in neuronal cells was studied with and without ectopic APE1 expression and the neuro- modulatory role of Ginkgolide B (from leaves of G. biloba) was evaluated. It was seen that A?(25-35) increases the ROS/RNS levels in these cells which was decreased when pre-treated with Ginkgolide B (G.B) before treating with A?(25-35). APE1 levels were found to be decreased on treating with A?(25-35) and were increased on pre- treatment with G.B and subsequent treatment with A?(25-35). These results indicate that ectopic APE1 expression in the mitochondria of the neuronal cells might overcome the oxidative damage caused by A?(25-35). Also, phytochemical G.B has shown to modulate the mitochondrial complex activity upon A?(25-35)-induced oxidative stress and modulate the ROS/RNS levels in the presence of APE1. Further studies are needed to understand the mechanism of action of APE1 in relation to the above results, which will be carried out during my Ph.D. work.
Elevated level of acetylation of APE1 in tumor cells modulates DNA damage repair
(Impact Journals LLC, 2016) Sengupta, S.; Mantha, Anil K.; Song, H.; Roychoudhury, S.; Nath, S.; Ray, S.; Bhakat, K.K.
Apurinic/apyrimidinic (AP) sites are frequently generated in the genome by spontaneous depurination/depyrimidination or after removal of oxidized/modified bases by DNA glycosylases during the base excision repair (BER) pathway. Unrepaired AP sites are mutagenic and block DNA replication and transcription. The primary enzyme to repair AP sites in mammalian cells is AP endonuclease (APE1), which plays a key role in this repair pathway. Although overexpression of APE1 in diverse cancer types and its association with chemotherapeutic resistance are well documented, alteration of posttranslational modification of APE1 and modulation of its functions during tumorigenesis are largely unknown. Here, we show that both classical histone deacetylase HDAC1 and NAD+-dependent deacetylase SIRT1 regulate acetylation level of APE1 and acetylation of APE1 enhances its AP-endonuclease activity both in vitro and in cells. Modulation of APE1 acetylation level in cells alters AP site repair capacity of the cell extracts in vitro. Primary tumor tissues of diverse cancer types have higher level of acetylated APE1 (AcAPE1) compared to adjacent non-tumor tissue and exhibit enhanced AP site repair capacity. Importantly, in the absence of APE1 acetylation, cells accumulate AP sites in the genome and show increased sensitivity to DNA damaging agents. Together, our study demonstrates that elevation of acetylation level of APE1 in tumor could be a novel mechanism by which cells handle the elevated levels of DNA damages in response to genotoxic stress and maintain sustained proliferation.
Essential oils and their constituents as anticancer agents: A mechanistic view
(Hindawi Publishing Corporation, 2014) Gautam, Nandini; Mantha, Anil K.; Mittal, Sunil
Exploring natural plant products as an option to find new chemical entities as anticancer agents is one of the fastest growing areas of research. Recently, in the last decade, essential oils (EOs) have been under study for their use in cancer therapy and the present review is an attempt to collect and document the available studies indicating EOs and their constituents as anticancer agents. This review enlists nearly 130 studies of EOs from various plant species and their constituents that have been studied so far for their anticancer potential and these studies have been classified as in vitro and in vivo studies for EOs and their constituents. This review also highlights in-depth various mechanisms of action of different EOs and their constituents reported in the treatment strategies for different types of cancer. The current review indicates that EOs and their constituents act by multiple pathways and mechanisms involving apoptosis, cell cycle arrest, antimetastatic and antiangiogenic, increased levels of reactive oxygen and nitrogen species (ROS/RNS), DNA repair modulation, and others to demonstrate their antiproliferative activity in the cancer cell. The effect of EOs and their constituents on tumour suppressor proteins (p53 and Akt), transcription factors (NF-B and AP-1), MAPK-pathway, and detoxification enzymes like SOD, catalase, glutathione peroxidase, and glutathione reductase has also been discussed. ? 2014 Nandini Gautam et al.