Browsing by Author "Chandra Bhushan Prasad"

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Anti-tumor activity of staurosporine in the tumor microenvironment of cervical cancer: An in vitro study
(Elsevier Inc., 2015) Suresh Singh Yadav; Chandra Bhushan Prasad; Shyam Babu Prasad; Lakshmi Kant Pandey; Sunita Singh; Satyajit Pradhan; Gopeshwar Narayan
Aim The fundamental events for cancer progression and metastases include loss of cell adhesion, cell proliferation, anchorage-independent cell growth (evading anoikis), cell migration and cell invasion. All these events leading to cancer progression happen in a favorable nurturing tumor microenvironment. This study was designed to explore the anti-tumor activity of staurosporine (a nonspecific protein kinase inhibitor) in the tumor microenvironment of cervical cancer. Main methods The anti-tumor activity of staurosporine was investigated by cell adhesion assay, colony formation assay, apoptosis assay and quantitative real-time polymerase chain reaction (PCR) in cervical cancer cell lines. Key findings The cell adhesion assay showed that staurosporine induces adhesion of cervical cancer cells to the extracellular matrix (ECM) protein fibronectin. The soft agar colony formation assay showed that staurosporine inhibits both the number and size of colony formation in a dose dependent manner and also induces adherent tendency in the cancer cells. Staurosporine also induces prominent apoptosis in single cell suspensions compared to adherent cells. Stroma cell induced transcription of matrix metalloprotease 1 (MMP1) and matrix metalloprotease 2 (MMP2) in cervical cancer cells was inhibited by staurosporine. Significance Our results indicate that staurosporine induces anti-tumor response in the cervical tumor microenvironment by inhibiting the fundamental events for cancer progression and metastases. The present study represents an attractive area for further research and opens up new avenues towards the understanding of cervical cancer therapeutics. © 2015 Elsevier Inc. All rights reserved.
CXCL12 is a key regulator in tumor microenvironment of cervical cancer: an in vitro study
(Springer Netherlands, 2016) Suresh Singh Yadav; Shyam Babu Prasad; Chandra Bhushan Prasad; Lakshmi Kant Pandey; Satyajit Pradhan; Sunita Singh; Gopeshwar Narayan
CXCL12 is a small pro-inflammatory chemo-attractant cytokine which signals through chemokine receptor CXCR4. The importance of CXCL12/CXCR4 axis is coming to the fore in several divergent signaling pathway-initiating signals related to cell survival and/or proliferation and cancer metastasis. In the present study we have investigated whether deregulation in CXCR4 signaling (as a consequence of deregulated expression of CXCL12) modulate the metastatic potential of cervical carcinoma cells. We demonstrate that CXCL12 is frequently down regulated and its promoter is hypermethylated in cervical cancer cell lines and primary tumor biopsies. Exogenous treatment of cervical cancer cell lines (HeLa, SiHa and C-33A) with recombinant CXCL12 inhibited the metastasis promoting cell migration, cell invasion and anchorage independent cell growth events. Although this study will need further in vivo validation, our observations suggest that (a) silencing of CXCL12 in cervical cancer cells may be critical in migration and invasion, the key events in cancer cell metastases; (b) cervical cancer cells having down regulated CXCL12 are more prone to being attracted to CXCL12 expressed at secondary sites of metastases; and (c) CXCL12 inhibits anchorage independent cell growth via anoikis. These findings suggest the tumor suppressor functions of CXCL12 in cervical cancer. © 2016, Springer Science+Business Media Dordrecht.
DNA Damage Response: A Therapeutic Landscape For Breast Cancer Treatment
(Bentham Science Publishers, 2022) Deepika Singh; Chandra Bhushan Prasad
Breast cancer is responsible for cancer-related death among women globally. The known causes of breast cancer include genetic predisposition, dysregulated hormonal signaling due to psychological stress, and aging and lifestyle factors, such as smoking and alcohol consumption. Due to improved treatment strategies, the overall survival is significantly increased; however, it is still significantly associated with death worldwide. Breast cancer's initiation and progression are strongly influenced by genomic instability. Defect in DNA damage response (DDR) pathways, which enable cells to survive, help in the accumulation of mutation, clonal selection, and expansion of cancer cells. Germline mutation in breast cancer susceptibility genes, BRCA1 and BRCA2, TP53, and PTEN, increases the risk of early onset of disease. During the initial and clonal selection of cancer cells, a defect in one DNA repair pathway could potentially be compensated by another pathway. Therefore, cancer cells with defective DNA repair pathways could be easily killed by targeting the compensatory pathways by inducing synthetic lethality. Evidently, cancer cells with defective DDR or decreased DNA repair capacity show synthetic lethality in monotherapy when the backup DNA repair pathway is inhibited. For instance, tumors with defective homologous recombination (HR) can be targeted by inhibitors of double-strand break repair enzymes. Here, we briefly addressed the relevant factors associated with the development of breast cancer and the role of the DDR factor in the development of breast cancer. In addition, recent treatment strategies targeting genomic instability in breast cancer will be summarized as well as how the genomic instability and defective DDR can be targeted for the treatment of breast cancer. © 2022, Bentham Books imprint.
Olaparib modulates DNA repair efficiency, sensitizes cervical cancer cells to cisplatin and exhibits anti-metastatic property
(Nature Publishing Group, 2017) Chandra Bhushan Prasad; Shyam Babu Prasad; Suresh Singh Yadav; Laxmi Kant Pandey; Sunita Singh; Satyajit Pradhan; Gopeshwar Narayan
PARP1 trapping at DNA lesion by pharmacological inhibitors has been exploited in several cancers exhibiting defects in DNA repair mechanisms. PARP1 hyperactivation is involved in therapeutic resistance in multiple cancers. The role of PARP1 in cervical cancer (CC) resistance and implication of PARP inhibitor is yet to be elucidated. Our data demonstrates significantly higher expression of PARP1 in primary cervical tumors and CC cell lines SiHa and ME180. Upon cisplatin treatment CC cells display significant overexpression of PARP1 and its hyperactivation. PARP inhibitor olaparib shows significant anti-proliferative effect on CC cells and drive loss of clonogenic survival and enhanced cell death in combination with cisplatin. PARP inhibited cells show delay in resolution of γH2A.X foci and prolonged late S and G2-M phase arrest resulting in apoptosis. Further, PARP inhibition disrupts the localization of base excision repair (BER) effector XRCC1 and non-homologous end joining (NHEJ) proteins Ku80 and XRCC4. Due to disrupted relocation of repair factors, cisplatin induced stalled replication forks collapse and convert into double strand breaks (DSBs). Interestingly, PARP inhibition also shows anti-migratory and anti-invasive properties in CC cells, increases anchorage independent cell death and induces anoikis. Collectively, our data demonstrates therapeutic potential of PARP inhibitor in cervical cancer. © 2017 The Author(s).
Resveratrol loaded PLGA:D-α-tocopheryl polyethylene glycol 1000 succinate blend nanoparticles for brain cancer therapy
(Royal Society of Chemistry, 2016) Mahalingam Rajamanickam Vijayakumar; Ramoji Kosuru; Sanjay Kumar Singh; Chandra Bhushan Prasad; Gopeshwar Narayan; Madaswamy S. Muthu; Sanjay Singh
trans-Resveratrol (RSV) is a natural molecule proved for cancer preventive and therapeutic activities without any potential side effects. In recent years, RSV is also proved for its cytotoxic potential against glioma. However, practical application of RSV in glioma chemotherapy is limited because of its low systemic circulation time and short biological half-life resulting from rapid metabolism and accelerated elimination from the blood pool. Therefore, the main objective of this study was to enhance systemic circulation time and short biological half-life of RSV using poly(d,l-lactide-co-glycolide)-d-α-tocopheryl polyethylene glycol 1000 succinate blend nanoparticles (RSV-PLGA-BNPs). RSV-PLGA-BNPs were successfully formulated and optimized by a single-emulsion solvent-evaporation technique. RSV-PLGA-BNPs were evaluated by various state of the art techniques for extensive nanoparticulate characterization. Cytotoxicity against C6 cells, cellular internalization and haemocompatibility were studied for proving anticancer potential and safety of RSV-PLGA-BNPs. Pharmacokinetic and tissue distribution studies were carried out in Charles Foster rats after intravenous (i.v) administration. RSV-PLGA-BNPs showed significantly higher cytotoxicity and excellent cell internalization in C6 glioma cells. Haemocompatibility studies suggested that RSV-PLGA-BNPs are safe for i.v administration. Pharmacokinetic studies showed prolonged systemic circulation of RSV-PLGA-BNPs up to 36 h with approximately 18.11 times higher plasma half-life than RSV solution. Tissue distribution studies showed higher brain accumulation of RSV-PLGA-BNPs than RSV. Therefore, RSV-PLGA-BNPs can be applied as a potential tool for enhancing systemic circulation and plasma half-life with superior anticancer efficacy against glioma. © 2016 The Royal Society of Chemistry.
TRAIL receptors are differentially regulated and clinically significant in gallbladder cancer
(Elsevier B.V., 2020) Deepika Singh; Chandra Bhushan Prasad; Dipanjan Biswas; Mallika Tewari; Amrita Ghosh Kar; Mumtaz Ahmed Ansari; Sunita Singh; Gopeshwar Narayan
Deregulation of the receptors of TNF-related apoptosis inducing ligand (TRAIL) has been reported in various cancers. In an effort to define the role of these receptors we profiled their expression in gallbladder cancer (GBC) and explored their clinical significance. Expression of TRAIL receptors' mRNA in GBC was analysed through reverse transcriptase polymerase chain reaction (RT-PCR), and protein through western blotting, immunohistochemistry and enzyme-linked immunosorbent assay (ELISA). mRNA data show frequent higher expression of TRAIL receptors in GBC samples. Death receptors DR4 and DR5 showed significant negative correlation with tumour stage, T stage and tumour grade; DcR1 transcript showed positive correlation with tumour stage, N stage, M stage and tumour grade. Similarly, IHC showed frequent positive staining for DR4, DR5 and DcR1in GBC samples. Cytoplasmic and nuclear DR4 protein showed negative correlation with T stage and tumour grade, whereas cytoplasmic DcR1 protein showed positive correlation with tumour stage and N stage. Nuclear DcR1 showed positive correlation with N stage. ELISA results showed significantly higher expression of secretory DcR1 in GBC patients. Kaplan–Meier analysis demonstrated significantly decreased mean survival of patients with positive staining of cytoplasmic DcR1. High level of death receptors identified the patients with early gallbladder cancer, whereas high DcR1 expression served as a prognostic factor for poor outcome. © 2020 Royal College of Pathologists of Australasia
VEGFa/VEGFR2 autocrine and paracrine signaling promotes cervical carcinogenesis via β-catenin and snail
(Elsevier Ltd, 2022) Chandra Bhushan Prasad; Deepika Singh; Laxmi Kant Pandey; Satyajit Pradhan; Sunita Singh; Gopeshwar Narayan
VEGF secretion into the tumor microenvironment by cancer cells regulates several oncogenic signaling pathways and cancer-regulated angiogenesis. VEGFR receptors are exclusively present on endothelial cells to maintain their biological homeostasis. The acquisition of unique VEGFR2 receptor and VEGFa in cervical cancer (CC) cells reflects VEGFa/VEGFR2 autocrine machinery. Given the critical role of VEGFR2 in endothelial cell proliferation, migration, and angiogenesis, we explored its function in CC epithelial-mesenchymal transition (EMT) and stemness. Here we report that VEGFR2 regulates cancer-induced angiogenesis and EMT-linked stemness in CC cells via AKT/GSK3β/β-catenin and Snail pathway. Receptor tyrosine kinase inhibitor (RTKi) of VEGFR, Pazopanib (PAZ), shows potential anti-VEGFR2 activity and inhibits VEGFa induced metastatic events such as migration, invasion, and anoikis resistance in CC cells. Similarly, PAZ also attenuates cancer-regulated angiogenesis by inhibiting VE-cadherin internalization in endothelial cells followed by inhibition of endothelial cell migration. Selective depletion of VEGFR2 ligand VEGFa in CC cells also attenuates EMT, metastatic events, and inhibition of cancer-induced angiogenesis. In addition, blocking of VEGFR2 signaling in CC cells via PAZ or shRNA alters the formation of cervical tumorspheres (TS) and their successive generation. Collectively, inhibition of functional VEGFa/VEGFR2 autocrine and paracrine axis ceases the cancer-promoting events in cervical cancer cells. Based on the finding in this study, this oncogenic pathways could be used as a potential therapeutic target in a clinical setting with conventional radio-chemotherapy to achieve synergistic killing of CC cells. © 2021 Elsevier Ltd