6 results on '"Vijayalakshmi, N."'
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2. Bithionol inhibits ovarian cancer cell growth In Vitro- studies on mechanism(s) of action
- Author
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Vijayalakshmi N. Ayyagari and Laurent Brard
- Subjects
Cancer Research ,Programmed cell death ,Time Factors ,Cell cycle checkpoint ,Apoptosis ,Antineoplastic Agents ,Pharmacology ,p38 Mitogen-Activated Protein Kinases ,Ovarian cancer cell lines ,Inhibitory Concentration 50 ,Cell Line, Tumor ,Genetics ,medicine ,Humans ,Viability assay ,Cell Proliferation ,Membrane Potential, Mitochondrial ,Ovarian Neoplasms ,Dose-Response Relationship, Drug ,Phosphoric Diester Hydrolases ,Cell growth ,business.industry ,NF-kappa B ,Cancer ,Cell Cycle Checkpoints ,medicine.disease ,XIAP ,Autotaxin ,Oncology ,Drug Resistance, Neoplasm ,Female ,Bithionol ,Cisplatin ,Apoptosis Regulatory Proteins ,Reactive Oxygen Species ,business ,Ovarian cancer ,Proto-Oncogene Proteins c-akt ,Research Article ,Signal Transduction - Abstract
Background Drug resistance is a cause of ovarian cancer recurrence and low overall survival rates. There is a need for more effective treatment approaches because the development of new drug is expensive and time consuming. Alternatively, the concept of ‘drug repurposing’ is promising. We focused on Bithionol (BT), a clinically approved anti-parasitic drug as an anti-ovarian cancer drug. BT has previously been shown to inhibit solid tumor growth in several preclinical cancer models. A better understanding of the anti-tumor effects and mechanism(s) of action of BT in ovarian cancer cells is essential for further exploring its therapeutic potential against ovarian cancer. Methods The cytotoxic effects of BT against a panel of ovarian cancer cell lines were determined by Presto Blue cell viability assay. Markers of apoptosis such as caspases 3/7, cPARP induction, nuclear condensation and mitochondrial transmembrane depolarization were assessed using microscopic, FACS and immunoblotting methods. Mechanism(s) of action of BT such as cell cycle arrest, reactive oxygen species (ROS) generation, autotaxin (ATX) inhibition and effects on MAPK and NF-kB signalling were determined by FACS analysis, immunoblotting and colorimetric methods. Results BT caused dose dependent cytotoxicity against all ovarian cancer cell lines tested with IC50 values ranging from 19 μM – 60 μM. Cisplatin-resistant variants of A2780 and IGROV-1 have shown almost similar IC50 values compared to their sensitive counterparts. Apoptotic cell death was shown by expression of caspases 3/7, cPARP, loss of mitochondrial potential, nuclear condensation, and up-regulation of p38 and reduced expression of pAkt, pNF-κB, pIκBα, XIAP, bcl-2 and bcl-xl. BT treatment resulted in cell cycle arrest at G1/M phase and increased ROS generation. Treatment with ascorbic acid resulted in partial restoration of cell viability. In addition, dose and time dependent inhibition of ATX was observed. Conclusions BT exhibits cytotoxic effects on various ovarian cancer cell lines regardless of their sensitivities to cisplatin. Cell death appears to be via caspases mediated apoptosis. The mechanisms of action appear to be partly via cell cycle arrest, ROS generation and inhibition of ATX. The present study provides preclinical data suggesting a potential therapeutic role for BT against recurrent ovarian cancer.
- Published
- 2014
3. Bithionol inhibits ovarian cancer cell growth In Vitro- studies on mechanism(s) of action
- Author
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Ayyagari, Vijayalakshmi N, primary and Brard, Laurent, additional
- Published
- 2014
- Full Text
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4. Evaluation of the cytotoxicity of the Bithionol - cisplatin combination in a panel of human ovarian cancer cell lines
- Author
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Tsung-han Jeff Hsieh, Paula L. Diaz-Sylvester, Laurent Brard, and Vijayalakshmi N. Ayyagari
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0301 basic medicine ,Cancer Research ,Combination therapy ,Apoptosis ,Pharmacology ,Ovarian cancer cell lines ,03 medical and health sciences ,0302 clinical medicine ,Cell Line, Tumor ,Antineoplastic Combined Chemotherapy Protocols ,medicine ,Biomarkers, Tumor ,Genetics ,Humans ,Cytotoxicity ,Drug combination ,chemistry.chemical_classification ,Cisplatin ,Ovarian Neoplasms ,Reactive oxygen species ,business.industry ,Cell cycle ,medicine.disease ,3. Good health ,XIAP ,030104 developmental biology ,Autotaxin ,chemistry ,Oncology ,Drug Resistance, Neoplasm ,030220 oncology & carcinogenesis ,Female ,Bithionol ,Ovarian cancer ,business ,Reactive Oxygen Species ,medicine.drug ,Research Article - Abstract
Background Combination drug therapy appears a promising approach to overcome drug resistance and reduce drug-related toxicities in ovarian cancer treatments. In this in vitro study, we evaluated the antitumor efficacy of cisplatin in combination with Bithionol (BT) against a panel of ovarian cancer cell lines with special focus on cisplatin-sensitive and cisplatin-resistant cell lines. The primary objectives of this study are to determine the nature of the interactions between BT and cisplatin and to understand the mechanism(s) of action of BT-cisplatin combination. Methods The cytotoxic effects of drugs either alone or in combination were evaluated using presto-blue assay. Cellular reactive oxygen species were measured by flow cytometry. Immunoblot analysis was carried out to investigate changes in levels of cleaved PARP, XIAP, bcl-2, bcl-xL, p21 and p27. Luminescent and colorimetric assays were used to test caspases 3/7 and ATX activity. Results The efficacy of the BT-cisplatin combination depends upon the cell type and concentrations of cisplatin and BT. In cisplatin-sensitive cell lines, BT and cisplatin were mostly antagonistic except when used at low concentrations, where synergy was observed. In contrast, in cisplatin-resistant cells, BT-cisplatin combination treatment displayed synergistic effects at most of the drug ratios/concentrations. Our results further revealed that the synergistic interaction was linked to increased reactive oxygen species generation and apoptosis. Enhanced apoptosis was correlated with loss of pro-survival factors (XIAP, bcl-2, bcl-xL), expression of pro-apoptotic markers (caspases 3/7, PARP cleavage) and enhanced cell cycle regulators p21 and p27. Conclusion In cisplatin-resistant cell lines, BT potentiated cisplatin-induced cytotoxicity at most drug ratios via enhanced ROS generation and modulation of key regulators of apoptosis. Low doses of BT and cisplatin enhanced efficiency of cisplatin treatment in all the ovarian cancer cell lines tested. Our results suggest that novel combinations such as BT and cisplatin might be an attractive therapeutic approach to enhance ovarian cancer chemosensitivity. Combining low doses of cisplatin with subtherapeutic doses of BT can ultimately lead to the development of an innovative combination therapy to reduce/prevent the side effects normally occurring when high doses of cisplatin are administered. Electronic supplementary material The online version of this article (doi:10.1186/s12885-016-3034-2) contains supplementary material, which is available to authorized users.
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5. Identification and validation of genes involved in cervical tumourigenesis.
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Rajkumar T, Sabitha K, Vijayalakshmi N, Shirley S, Bose MV, Gopal G, and Selvaluxmy G
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- Alphapapillomavirus genetics, Cell Transformation, Neoplastic pathology, Cells, Cultured, DNA, Viral genetics, Female, Gene Expression Profiling, Gene Expression Regulation, Neoplastic, Genes, Viral, HeLa Cells, Humans, Microarray Analysis, Uterine Cervical Neoplasms metabolism, Uterine Cervical Neoplasms pathology, Uterine Cervical Dysplasia metabolism, Uterine Cervical Dysplasia pathology, Cell Transformation, Neoplastic genetics, Genes, Neoplasm, Uterine Cervical Neoplasms genetics, Uterine Cervical Dysplasia genetics
- Abstract
Background: Cervical cancer is the most common cancer among Indian women. This cancer has well defined pre-cancerous stages and evolves over 10-15 years or more. This study was undertaken to identify differentially expressed genes between normal, dysplastic and invasive cervical cancer., Materials and Methods: A total of 28 invasive cervical cancers, 4 CIN3/CIS, 4 CIN1/CIN2 and 5 Normal cervix samples were studied. We have used microarray technique followed by validation of the significant genes by relative quantitation using Taqman Low Density Array Real Time PCR. Immunohistochemistry was used to study the protein expression of MMP3, UBE2C and p16 in normal, dysplasia and cancers of the cervix. The effect of a dominant negative UBE2C on the growth of the SiHa cells was assessed using a MTT assay., Results: Our study, for the first time, has identified 20 genes to be up-regulated and 14 down-regulated in cervical cancers and 5 up-regulated in CIN3. In addition, 26 genes identified by other studies, as to playing a role in cervical cancer, were also confirmed in our study. UBE2C, CCNB1, CCNB2, PLOD2, NUP210, MELK, CDC20 genes were overexpressed in tumours and in CIN3/CIS relative to both Normal and CIN1/CIN2, suggesting that they could have a role to play in the early phase of tumorigenesis. IL8, INDO, ISG15, ISG20, AGRN, DTXL, MMP1, MMP3, CCL18, TOP2A AND STAT1 were found to be upregulated in tumours. Using Immunohistochemistry, we showed over-expression of MMP3, UBE2C and p16 in cancers compared to normal cervical epithelium and varying grades of dysplasia. A dominant negative UBE2C was found to produce growth inhibition in SiHa cells, which over-expresses UBE2C 4 fold more than HEK293 cells., Conclusions: Several novel genes were found to be differentially expressed in cervical cancer. MMP3, UBE2C and p16 protein overexpression in cervical cancers was confirmed by immunohistochemistry. These will need to be validated further in a larger series of samples. UBE2C could be evaluated further to assess its potential as a therapeutic target in cervical cancer.
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- 2011
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6. A 7 gene expression score predicts for radiation response in cancer cervix.
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Rajkumar T, Vijayalakshmi N, Sabitha K, Shirley S, Selvaluxmy G, Bose MV, and Nambaru L
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- Female, Humans, Neoplasm Staging, Predictive Value of Tests, Treatment Outcome, Uterine Cervical Neoplasms pathology, Gene Expression Regulation, Neoplastic, Uterine Cervical Neoplasms genetics, Uterine Cervical Neoplasms radiotherapy
- Abstract
Background: Cervical cancer is the most common cancer among Indian women. The current recommendations are to treat the stage IIB, IIIA, IIIB and IVA with radical radiotherapy and weekly cisplatin based chemotherapy. However, Radiotherapy alone can help cure more than 60% of stage IIB and up to 40% of stage IIIB patients., Methods: Archival RNA samples from 15 patients who had achieved complete remission and stayed disease free for more than 36 months (No Evidence of Disease or NED group) and 10 patients who had failed radical radiotherapy (Failed group) were included in the study. The RNA were amplified, labelled and hybridized to Stanford microarray chips and analyzed using BRB Array Tools software and Significance Analysis of Microarray (SAM) analysis. 20 genes were selected for further validation using Relative Quantitation (RQ) Taqman assay in a Taqman Low-Density Array (TLDA) format. The RQ value was calculated, using each of the NED sample once as a calibrator. A scoring system was developed based on the RQ value for the genes., Results: Using a seven gene based scoring system, it was possible to distinguish between the tumours which were likely to respond to the radiotherapy and those likely to fail. The mean score +/- 2 SE (standard error of mean) was used and at a cut-off score of greater than 5.60, the sensitivity, specificity, Positive predictive value (PPV) and Negative predictive value (NPV) were 0.64, 1.0, 1.0, 0.67, respectively, for the low risk group., Conclusion: We have identified a 7 gene signature which could help identify patients with cervical cancer who can be treated with radiotherapy alone. However, this needs to be validated in a larger patient population.
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- 2009
- Full Text
- View/download PDF
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