Kumaravel Somasundaram

Publications of Kumaravel Somasundaram

• Mode of cell death associated with adenovirus-mediated suicide gene therapy in HNSCC tumor model.

  Authors: Deepika Srivastava, Ganesh Joshi, Kumaravel Somasundaram, Rita Mulherkar

  Anticancer research. 11/2011; 31(11):3851-7.

  Adenoviral mediated suicide gene therapy has been shown to have a tumoricidal effect against a variety of tumor models. Although the efficacy of this treatment regimen has been verified, theAdenoviral mediated suicide gene therapy has been shown to have a tumoricidal effect against a variety of tumor models. Although the efficacy of this treatment regimen has been verified, the molecular mechanism of Herpes simplex virus thymidine kinase gene (HSVtk)- and ganciclovir (GCV)-induced cell death is still not well established. The mode of cell death by adenoviral (Adv)-HSVtk/GCV was examined in the head and neck squamous cell carcinoma cell line, NT8e. The cell death was independent of apoptotic gene expression. Moreover apoptosis was not evident from cell cycle kinetic analysis. Adv-HSVtk/GCV treated cells showed time dependent accumulation of cells in the S-phase of the cell cycle although there was no increase in the "apoptotic peak" or sub-G1 population. Swelling of the cytoplasm without apparent nuclear condensation suggested a possible involvement of necrosis. The apoptotic mechanism may not play a central role in the Adv-HSVtk/GCV induced NT8e cell death and other mechanisms should be considered.

• MicroRNA (miRNA) Regulation in Glioma: Implications in Development, Progression, Grading, Prognosis and Therapy

  Authors: Kumaravel Somasundaram, Soumya Alige Mahabala Rao, Zahid Nawaz

  09/2011;

  ISBN: 978-953-307-736-9

• Glioma Proteomics: Methods and Current Perspective

  Authors: Kumaravel Somasundaram, Mamatha B Nijaguna, Durairaj Mohan Kumar

  08/2011;

  ISBN: 978-953-307-588-4

• Insulin growth factor-2 binding protein 3 (IGF2BP3) is a glioblastoma-specific marker that activates phosphatidylinositol 3-kinase/mitogen-activated protein kinase (PI3K/MAPK) pathways by modulating IGF-2.

  Authors: Ramaswamy Suvasini, Bhargava Shruti, Balaram Thota, Sridevi Vijay Shinde, Dinorah Friedmann-Morvinski, Zahid Nawaz, Krishnarao Venkatesh Prasanna, Kandavel Thennarasu, Alangar Sathyaranjandas Hegde, Arimappamagan Arivazhagan, Bangalore Ashwathnarayanarao Chandramouli, Vani Santosh, Kumaravel Somasundaram

  The Journal of biological chemistry. 05/2011; 286(29):25882-90.

  Glioblastoma is the most common and malignant form of primary astrocytoma. Upon investigation of the insulin-like growth factor (IGF) pathway, we found the IGF2BP3/IMP3 transcript and protein to beGlioblastoma is the most common and malignant form of primary astrocytoma. Upon investigation of the insulin-like growth factor (IGF) pathway, we found the IGF2BP3/IMP3 transcript and protein to be up-regulated in GBMs but not in lower grade astrocytomas (p < 0.0001). IMP3 is an RNA binding protein known to bind to the 5'-untranslated region of IGF-2 mRNA, thereby activating its translation. Overexpression- and knockdown-based studies establish a role for IMP3 in promoting proliferation, anchorage-independent growth, invasion, and chemoresistance. IMP3 overexpressing B16F10 cells also showed increased tumor growth, angiogenesis, and metastasis, resulting in poor survival in a mouse model. Additionally, the infiltrating front, perivascular, and subpial regions in a majority of the GBMs stained positive for IMP3. Furthermore, two different murine glioma models were used to substantiate the above findings. In agreement with the translation activation functions of IMP3, we also found increased IGF-2 protein in the GBM tumor samples without a corresponding increase in its transcript levels. Also, in vitro IMP3 overexpression/knockdown modulated the IGF-2 protein levels without altering its transcript levels. Additionally, IGF-2 neutralization and supplementation studies established that the proproliferative effects of IMP3 were indeed mediated through IGF-2. Concordantly, PI3K and MAPK, the downstream effectors of IGF-2, are activated by IMP3 and are found to be essential for IMP3-induced cell proliferation. Thus, we have identified IMP3 as a GBM-specific proproliferative and proinvasive marker acting through IGF-2 resulting in the activation of oncogenic PI3K and MAPK pathways.

• A novel zinc bis(thiosemicarbazone) complex for live cell imaging.

  Authors: Disha Dayal, Duraippandi Palanimuthu, Sridevi Vijay Shinde, Kumaravel Somasundaram, Ashoka G Samuelson

  Journal of biological inorganic chemistry : JBIC : a publication of the Society of Biological Inorganic Chemistry. 03/2011; 16(4):621-32.

  Fluorescent zinc complexes have recently attracted a lot of interest owing to their vast applications in cellular imaging. We report the synthesis as well as physical, chemical and biological studiesFluorescent zinc complexes have recently attracted a lot of interest owing to their vast applications in cellular imaging. We report the synthesis as well as physical, chemical and biological studies of a novel zinc glyoxalbis(4-methyl-4-phenyl-3-thiosemicarbazone), [Zn(GTSC)]₃, complex. As compared with the well-studied zinc biacetylbis(4-methyl-3-thiosemicarbazone), Zn(ATSM), complex, which was used as a reference, [Zn(GTSC)]₃ had 2.5-fold higher fluorescence. When cellular fluorescence was measured using flow cytometry, we observed that [Zn(GTSC)]₃ had 3.4-fold to 12-fold higher fluorescence than Zn(ATSM) in various cell lines (n = 9) of different tissue origin. Confocal fluorescence microscopy results showed that [Zn(GTSC)]₃ appeared to have a nuclear localization within 30 min of addition to MCF7 cells. Moreover, [Zn(GTSC)]₃ showed minimal cytotoxicity compared with Zn(ATSM), suggesting that [Zn(GTSC)]₃ may be less deleterious to cells when used as an imaging agent. Our data suggest that the novel [Zn(GTSC)]₃ complex can potentially serve as a biocompatible fluorescent imaging agent for live cells.

• A ten-microRNA expression signature predicts survival in glioblastoma.

  Authors: Sujaya Srinivasan, Irene Rosita Pia Patric, Kumaravel Somasundaram

  PloS one. 01/2011; 6(3):e17438.

  Glioblastoma (GBM) is the most common and aggressive primary brain tumor with very poor patient median survival. To identify a microRNA (miRNA) expression signature that can predict GBM patientGlioblastoma (GBM) is the most common and aggressive primary brain tumor with very poor patient median survival. To identify a microRNA (miRNA) expression signature that can predict GBM patient survival, we analyzed the miRNA expression data of GBM patients (n=222) derived from The Cancer Genome Atlas (TCGA) dataset. We divided the patients randomly into training and testing sets with equal number in each group. We identified 10 significant miRNAs using Cox regression analysis on the training set and formulated a risk score based on the expression signature of these miRNAs that segregated the patients into high and low risk groups with significantly different survival times (hazard ratio [HR]=2.4; 95% CI=1.4-3.8; p<0.0001). Of these 10 miRNAs, 7 were found to be risky miRNAs and 3 were found to be protective. This signature was independently validated in the testing set (HR=1.7; 95% CI=1.1-2.8; p=0.002). GBM patients with high risk scores had overall poor survival compared to the patients with low risk scores. Overall survival among the entire patient set was 35.0% at 2 years, 21.5% at 3 years, 18.5% at 4 years and 11.8% at 5 years in the low risk group, versus 11.0%, 5.5%, 0.0 and 0.0% respectively in the high risk group (HR=2.0; 95% CI=1.4-2.8; p<0.0001). Cox multivariate analysis with patient age as a covariate on the entire patient set identified risk score based on the 10 miRNA expression signature to be an independent predictor of patient survival (HR=1.120; 95% CI=1.04-1.20; p=0.003). Thus we have identified a miRNA expression signature that can predict GBM patient survival. These findings may have implications in the understanding of gliomagenesis, development of targeted therapy and selection of high risk cancer patients for adjuvant therapy.

• Virtual screening, identification and experimental testing of novel inhibitors of PBEF1/Visfatin/NMPRTase for glioma therapy.

  Authors: Nagasuma Chandra, Raghu Bhagavat, Eshita Sharma, P Sreekanthreddy, Kumaravel Somasundaram

  Journal of clinical bioinformatics. 01/2011; 1(1):5.

  ABSTRACT: Pre-B-cell colony enhancing factor 1 gene (PBEF1) encodes nicotinamide phosphoribosyltransferase (NMPRTase), which catalyses the rate limiting step in the salvage pathway of NAD+ metabolismABSTRACT: Pre-B-cell colony enhancing factor 1 gene (PBEF1) encodes nicotinamide phosphoribosyltransferase (NMPRTase), which catalyses the rate limiting step in the salvage pathway of NAD+ metabolism in mammalian cells. PBEF1 transcript and protein levels have been shown to be elevated in glioblastoma and a chemical inhibitor of NMPRTase has been shown to specifically inhibit cancer cells. Virtual screening using docking was used to screen a library of more than 13,000 chemical compounds. A shortlisted set of compounds were tested for their inhibition activity in vitro by an NMPRTase enzyme assay. Further, the ability of the compounds to inhibit glioma cell proliferation was carried out. Virtual screening resulted in short listing of 34 possible ligands, of which six were tested experimentally, using the NMPRTase enzyme inhibition assay and further with the glioma cell viability assays. Of these, two compounds were found to be significantly efficacious in inhibiting the conversion of nicotinamide to NAD+, and out of which, one compound, 3-amino-2-benzyl-7-nitro-4-(2-quinolyl-)-1,2-dihydroisoquinolin-1-one, was found to inhibit the growth of a PBEF1 over expressing glioma derived cell line U87 as well. Thus, a novel inhibitor has been identified through a structure based drug discovery approach and is further supported by experimental evidence.

• Proteomic identification of haptoglobin α2 as a glioblastoma serum biomarker: implications in cancer cell migration and tumor growth.

  Authors: Durairaj Mohan Kumar, Balaram Thota, Sridevi Vijay Shinde, K V Prasanna, A S Hegde, A Arivazhagan, B A Chandramouli, Vani Santosh, Kumaravel Somasundaram

  Journal of proteome research. 11/2010; 9(11):5557-67.

  Glioblastoma (GBM; grade IV astrocytoma) is the most malignant and common primary brain tumor in adults. Using combination of 2-DE and MALDI-TOF MS, we analyzed 14 GBM and 6 normal control sera andGlioblastoma (GBM; grade IV astrocytoma) is the most malignant and common primary brain tumor in adults. Using combination of 2-DE and MALDI-TOF MS, we analyzed 14 GBM and 6 normal control sera and identified haptoglobin α2 chain as an up-regulated serum protein in GBM patients. GBM-specific up-regulation was confirmed by ELISA based quantitation of haptoglobin (Hp) in the serum of 99 GBM patients as against lower grades (49 grade III/AA; 26 grade II/DA) and 26 normal individuals (p = 0.0001). Further validation using RT-qPCR on an independent set (n = 78) of tumor and normal brain (n = 4) samples and immunohistochemcial staining on a subset (n = 42) of above samples showed increasing levels of transcript and protein with tumor grade and were highest in GBM (p = <0.0001 and <0.0001, respectively). Overexpression of Hp either by stable integration of Hp cDNA or exogenous addition of purified Hp to immortalized astrocytes resulted in increased cell migration. RNAi-mediated silencing of Hp in glioma cells decreased cell migration. Further, we demonstrate that both human glioma and mouse melanoma cells overexpressing Hp showed increased tumor growth. Thus, we have identified haptoglobin as a GBM-specific serum marker with a role on glioma tumor growth and migration.

• Genome-wide expression profiling identifies deregulated miRNAs in malignant astrocytoma.

  Authors: Soumya A M Rao, Vani Santosh, Kumaravel Somasundaram

  Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc. 10/2010; 23(10):1404-17.

  Malignant astrocytoma includes anaplastic astrocytoma (grade III) and glioblastoma (grade IV). Among them, glioblastoma is the most common primary brain tumor with dismal responses to all therapeuticMalignant astrocytoma includes anaplastic astrocytoma (grade III) and glioblastoma (grade IV). Among them, glioblastoma is the most common primary brain tumor with dismal responses to all therapeutic modalities. We performed a large-scale, genome-wide microRNA (miRNA) (n=756) expression profiling of 26 glioblastoma, 13 anaplastic astrocytoma and 7 normal brain samples with an aim to find deregulated miRNA in malignant astrocytoma. We identified several differentially regulated miRNAs between these groups, which could differentiate glioma grades and normal brain as recognized by PCA. More importantly, we identified a most discriminatory 23-miRNA expression signature, by using PAM, which precisely distinguished glioblastoma from anaplastic astrocytoma with an accuracy of 95%. The differential expression pattern of nine miRNAs was further validated by real-time RT-PCR on an independent set of malignant astrocytomas (n=72) and normal samples (n=7). Inhibition of two glioblastoma-upregulated miRNAs (miR-21 and miR-23a) and exogenous overexpression of two glioblastoma-downregulated miRNAs (miR-218 and miR-219-5p) resulted in reduced soft agar colony formation but showed varying effects on cell proliferation and chemosensitivity. Thus we have identified the miRNA expression signature for malignant astrocytoma, in particular glioblastoma, and showed the miRNA involvement and their importance in astrocytoma development.

• Glioblastoma-specific protein interaction network identifies PP1A and CSK21 as connecting molecules between cell cycle-associated genes.

  Authors: Jayashree Ladha, Sainitin Donakonda, Shipra Agrawal, Balaram Thota, Mallavarapu R Srividya, Sambandam Sridevi, Arimappamagan Arivazhagan, Kandavel Thennarasu, Anandh Balasubramaniam, Bangalore A Chandramouli, Alangar Sattiyaranjandas Hegde, Paturu Kondaiah, Kumaravel Somasundaram, Vani Santosh, Satyanarayana M R Rao

  Cancer research. 08/2010; 70(16):6437-47.

  Glioblastoma (GBM; grade IV astrocytoma) is a very aggressive form of brain cancer with a poor survival and few qualified predictive markers. This study integrates experimentally validated genes thatGlioblastoma (GBM; grade IV astrocytoma) is a very aggressive form of brain cancer with a poor survival and few qualified predictive markers. This study integrates experimentally validated genes that showed specific upregulation in GBM along with their protein-protein interaction information. A system level analysis was used to construct GBM-specific network. Computation of topological parameters of networks showed scale-free pattern and hierarchical organization. From the large network involving 1,447 proteins, we synthesized subnetworks and annotated them with highly enriched biological processes. A careful dissection of the functional modules, important nodes, and their connections identified two novel intermediary molecules CSK21 and protein phosphatase 1 alpha (PP1A) connecting the two subnetworks CDC2-PTEN-TOP2A-CAV1-P53 and CDC2-CAV1-RB-P53-PTEN, respectively. Real-time quantitative reverse transcription-PCR analysis revealed CSK21 to be moderately upregulated and PP1A to be overexpressed by 20-fold in GBM tumor samples. Immunohistochemical staining revealed nuclear expression of PP1A only in GBM samples. Thus, CSK21 and PP1A, whose functions are intimately associated with cell cycle regulation, might play key role in gliomagenesis.

• Identification of potential serum biomarkers of glioblastoma: serum osteopontin levels correlate with poor prognosis.

  Authors: Peddagangannagari Sreekanthreddy, Harish Srinivasan, Durairaj Mohan Kumar, Mamatha Bangalore Nijaguna, Sambandam Sridevi, Marigowda Vrinda, Arimappamagan Arivazhagan, Anandh Balasubramaniam, Alangar Sathyaranjandas Hegde, Bangalore A Chandramouli, Vani Santosh, Manchanahalli R S Rao, Paturu Kondaiah, Kumaravel Somasundaram

  Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology. 06/2010; 19(6):1409-22.

  The aim of this study is to identify serum biomarkers with classification and prognosis utility for astrocytoma, in particular glioblastoma (GBM). Our previous glioma microarray database was mined toThe aim of this study is to identify serum biomarkers with classification and prognosis utility for astrocytoma, in particular glioblastoma (GBM). Our previous glioma microarray database was mined to identify genes that encode secreted or membrane-localized proteins. Subsequent analysis was done using significant analysis of microarrays, followed by reverse transcription-quantitative PCR (RT-qPCR) and immunohistochemical validation in tumor tissues, ELISA and Western blot validation in sera, and correlation with survival of GBM patients. Significant analysis of microarrays identified 31 upregulated and 3 downregulated genes specifically in GBMs. RT-qPCR validation on an independent set of samples confirmed the GBM-specific differential expression of several genes, including three upregulated (CALU, CXCL9, and TIMP1) and two downregulated (GPX3 and TIMP3) novel genes. With respect to osteopontin (OPN), we show the GBM-specific upregulation by RT-qPCR and immunohistochemical staining of tumor tissues. Elevated serum OPN levels in GBM patients were also shown by ELISA and Western blot. GBM patients with high serum OPN levels had poorer survival than those with low serum OPN levels (median survival 9 versus 22 months respectively; P = 0.0001). Further, we also show high serum TIMP1 levels in GBM patients compared with grade II/III patients by ELISA and downregulation of serum GPX3 and TIMP3 proteins in GBMs compared with normal control by Western blot analysis. Several novel potential serum biomarkers of GBM are identified and validated. High serum OPN level is found as a poor prognostic indicator in GBMs. Identified serum biomarkers may have potential utility in astrocytoma classification and GBM prognosis.

• Grade-specific expression of insulin-like growth factor-binding proteins-2, -3, and -5 in astrocytomas: IGFBP-3 emerges as a strong predictor of survival in patients with newly diagnosed glioblastoma.

  Authors: Vani Santosh, Arimappamagan Arivazhagan, Peddagangannagari Sreekanthreddy, Harish Srinivasan, Balaram Thota, Mallavarapu R Srividya, Marigowda Vrinda, Sambandam Sridevi, Bangalore C Shailaja, Cini Samuel, Krishnarao V Prasanna, Kandavel Thennarasu, Anandh Balasubramaniam, Bangalore A Chandramouli, Alangar S Hegde, Kumaravel Somasundaram, Paturu Kondaiah, Manchanahalli R S Rao

  Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology. 06/2010; 19(6):1399-408.

  Insulin-like growth factor (IGF)-binding protein (IGFBP) isoforms have been implicated in the pathogenesis of human neoplasms including glioma. In view of this, we evaluated the expression of IGFBPInsulin-like growth factor (IGF)-binding protein (IGFBP) isoforms have been implicated in the pathogenesis of human neoplasms including glioma. In view of this, we evaluated the expression of IGFBP isoforms (IGFBP-2, -3, and -5) during malignant progression of astrocytoma and their prognostic significance in glioblastoma. The expression of IGFBP isoforms was analyzed in diffusely infiltrating astrocytomas by real-time quantitative PCR (n = 203) and immunohistochemistry (n = 256). Statistical methods were used to assess their grade-specific expression pattern and mRNA-protein intercorrelation. Survival analyses were done on a uniformly treated, prospective cohort of adult patients with newly diagnosed glioblastoma (n = 136) by using Cox regression models. The mean transcript levels of IGFBP-2 and -3 were significantly higher in glioblastomas (GBM) relative to anaplastic astrocytoma (AA), diffuse astrocytoma (DA), and controls whereas IGFBP-5 mRNA was higher in GBM relative to AA and controls (P < 0.05). By immunohistochemistry, the mean labeling index of all isoforms was significantly higher in GBM compared with AA, DA, and control (P < 0.05). A strong positive correlation was observed between their respective mRNA and protein expressions (P < 0.01). Multivariate analysis revealed IGFBP-3 expression (hazard ratio, 1.021; P = 0.030) and patient age (hazard ratio, 1.027; P = 0.007) to be associated with shorter survival in glioblastoma. This study shows the associations of IGFBP-2, -3, and -5 expression with increasing grades of malignancy in astrocytomas. IGFBP-3 is identified as a novel prognostic glioblastoma biomarker. The strong correlation between their mRNA and protein expression patterns suggests their role in the pathogenesis of these tumors. IGFBP isoforms have emerged as biomarkers with diagnostic and prognostic utility in astrocytomas.

• Cytotoxicity of half sandwich ruthenium(II) complexes with strong hydrogen bond acceptor ligands and their mechanism of action.

  Authors: Sangeeta Das, Sarika Sinha, Ramona Britto, Kumaravel Somasundaram, Ashoka G Samuelson

  Journal of inorganic biochemistry. 10/2009;

  Neutral and cationic organometallic ruthenium(II) piano stool complexes of the type [(eta(6)-cymene)RuCl(X)(Y)] (complexes R1-R8) has been synthesized and characterized. In cationic complexes, X, YNeutral and cationic organometallic ruthenium(II) piano stool complexes of the type [(eta(6)-cymene)RuCl(X)(Y)] (complexes R1-R8) has been synthesized and characterized. In cationic complexes, X, Y is either a eta(2) phosphorus ligand such as 1,1-bis(diphenylphosphino)methane (DPPM) and 1,2-bis(diphenylphosphino)ethane (DPPE) or partially oxidized ligands such as 1,2-bis(diphenylphosphino)methane monooxide (DPPMO) and 1,2-bis(diphenylphosphino)ethane monooxide (DPPEO) which are strong hydrogen bond acceptors. In neutral complexes, X is chloride and Y is a monodentate phosphorous donor. Complexes with DPPM and DPPMO ligands ([(eta(6)-cymene)Ru(eta(2)-DPPM)Cl]PF(6) (R2), [(eta(6)-cymene)Ru(eta(2)-DPPMO)Cl]PF(6) (R3), [(eta(6)-cymene)Ru(eta(1)-DPPM)Cl(2)] (R5) and [(eta(6)-cymene)Ru(eta(1)-DPPMO)Cl(2)] (R6) show good cytotoxicity. Growth inhibition study of several human cancer cell lines by these complexes has been carried out. Mechanistic studies for R5 and R6 show that inhibition of cancer cell growth involves both cell cycle arrest and apoptosis induction. Using an apoptosis PCR array, we identified the sets of anti-apoptotic genes that were down regulated and pro-apoptotic genes that were up regulated. These complexes were also found to be potent metastasis inhibitors as they prevented cell invasion through matrigel. The complexes were shown to bind DNA in a non intercalative fashion and cause unwinding of plasmid DNA in cell-free medium by competitive ethidium bromide binding, viscosity measurements, thermal denaturation and gel mobility shift assays.

• Serum proteomics of glioma: methods and applications.

  Authors: Kumaravel Somasundaram, Mamatha B Nijaguna, Durairaj Mohan Kumar

  Expert review of molecular diagnostics. 10/2009; 9(7):695-707.

  The prognosis of patients with glioblastoma, the most malignant adult glial brain tumor, remains poor in spite of advances in treatment procedures, including surgical resection, irradiation andThe prognosis of patients with glioblastoma, the most malignant adult glial brain tumor, remains poor in spite of advances in treatment procedures, including surgical resection, irradiation and chemotherapy. Genetic heterogeneity of glioblastoma warrants extensive studies in order to gain a thorough understanding of the biology of this tumor. While there have been several studies of global transcript profiling of glioma with the identification of gene signatures for diagnosis and disease management, translation into clinics is yet to happen. Serum biomarkers have the potential to revolutionize the process of cancer diagnosis, grading, prognostication and treatment response monitoring. Besides having the advantage that serum can be obtained through a less invasive procedure, it contains molecules at an extraordinary dynamic range of ten orders of magnitude in terms of their concentrations. While the conventional methods, such as 2DE, have been in use for many years, the ability to identify the proteins through mass spectrometry techniques such as MALDI-TOF led to an explosion of interest in proteomics. Relatively new high-throughput proteomics methods such as SELDI-TOF and protein microarrays are expected to hasten the process of serum biomarker discovery. This review will highlight the recent advances in the proteomics platform in discovering serum biomarkers and the current status of glioma serum markers. We aim to provide the principles and potential of the latest proteomic approaches and their applications in the biomarker discovery process. Besides providing a comprehensive list of available serum biomarkers of glioma, we will also propose how these markers will revolutionize the clinical management of glioma patients.

• BRCA1 and BRCA2 germline mutation analysis among Indian women from south India: identification of four novel mutations and high-frequency occurrence of 185delAG mutation.

  Authors: Kannan Vaidyanathan, Smita Lakhotia, H M Ravishankar, Umaira Tabassum, Geetashree Mukherjee, Kumaravel Somasundaram

  Journal of biosciences. 09/2009; 34(3):415-22.

  Mutations in the BRCA1 and BRCA2 genes profoundly increase the risk of developing breast and/or ovarian cancer among women. To explore the contribution of BRCA1 and BRCA2 mutations in the developmentMutations in the BRCA1 and BRCA2 genes profoundly increase the risk of developing breast and/or ovarian cancer among women. To explore the contribution of BRCA1 and BRCA2 mutations in the development of hereditary breast cancer among Indian women, we carried out mutation analysis of the BRCA1 and BRCA2 genes in 61 breast or ovarian cancer patients from south India with a positive family history of breast and/or ovarian cancer. Mutation analysis was carried out using conformation-sensitive gel electrophoresis (CSGE) followed by sequencing. Mutations were identified in 17 patients (28.0%); 15 (24.6%) had BRCA1 mutations and two (3.28%) had BRCA2 mutations. While no specific association between BRCA1 or BRCA2 mutations with cancer type was seen, mutations were more often seen in families with ovarian cancer. While 40% (4/10) and 30.8% (4/12) of families with ovarian or breast and ovarian cancer had mutations, only 23.1% (9/39) of families with breast cancer carried mutations in the BRCA1 and BRCA2 genes. In addition, while BRCA1 mutations were found in all age groups, BRCA2 mutations were found only in the age group of </=40 years. Of the BRCA1 mutations, there were three novel mutations (295delCA; 4213T-->A; 5267T-->G) and three mutations that have been reported earlier. Interestingly, 185delAG, a BRCA1 mutation which occurs at a very high frequency in Ashkenazi Jews, was found at a frequency of 16.4% (10/61). There was one novel mutation (4866insT) and one reported mutation in BRCA2. Thus, our study emphasizes the importance of mutation screening in familial breast and/or ovarian cancers, and the potential implications of these findings in genetic counselling and preventive therapy.

• HDAC inhibitor valproic acid enhances tumour cell kill in adenovirus-HSVtk mediated suicide gene therapy in HNSCC xenograft mouse model.

  Authors: Vishal Kothari, Ganesh Joshi, Srikanth Nama, Kumaravel Somasundaram, Rita Mulherkar

  International journal of cancer. Journal international du cancer. 07/2009;

  Safety, efficacy and enhanced transgene expression are the primary concerns while using any vector for gene therapy. One of the widely used vectors in clinical trials is adenovirus which provides aSafety, efficacy and enhanced transgene expression are the primary concerns while using any vector for gene therapy. One of the widely used vectors in clinical trials is adenovirus which provides a safe way to deliver the therapeutic gene. However, adenovirus has poor transduction efficiency in vivo since most tumour cells express low Coxsackie and Adenovirus Receptors. Similarly transgene expression remains low, possibly because of the chromatization of adenoviral genome upon infection in eukaryotic cells, an effect mediated by Histone Deacetylases (HDACs). Using a recombinant adenovirus (Ad-HSVtk) carrying the Herpes simplex thymidine kinase (HSVtk) and GFP genes we demonstrate that HDAC inhibitor Valproic Acid can bring about an increase in CAR expression on host cells and thereby enhanced Ad-HSVtk infectivity. It also resulted in an increase in transgene (HSVtk and GFP) expression. This, in turn, resulted in increased cell kill of HNSCC cells, following ganciclovir treatment in vitro as well as in vivo in a xenograft nude mouse model. (c) 2009 UICC.

• Novel glioblastoma markers with diagnostic and prognostic value identified through transcriptome analysis.

  Authors: Sreekanth P Reddy, Ramona Britto, Katyayni Vinnakota, Hebbar Aparna, Hari Kishore Sreepathi, Balaram Thota, Arpana Kumari, B M Shilpa, M Vrinda, Srikantha Umesh [......] Ashwani Tandon, Paritosh Pandey, Sridevi Hegde, A S Hegde, Anandh Balasubramaniam, B A Chandramouli, Vani Santosh, Paturu Kondaiah, Kumaravel Somasundaram, M R Satyanarayana Rao

  Clinical cancer research : an official journal of the American Association for Cancer Research. 06/2008; 14(10):2978-87.

  PURPOSE: Current methods of classification of astrocytoma based on histopathologic methods are often subjective and less accurate. Although patients with glioblastoma have grave prognosis,PURPOSE: Current methods of classification of astrocytoma based on histopathologic methods are often subjective and less accurate. Although patients with glioblastoma have grave prognosis, significant variability in patient outcome is observed. Therefore, the aim of this study was to identify glioblastoma diagnostic and prognostic markers through microarray analysis. EXPERIMENTAL DESIGN: We carried out transcriptome analysis of 25 diffusely infiltrating astrocytoma samples [WHO grade II--diffuse astrocytoma, grade III--anaplastic astrocytoma, and grade IV--glioblastoma (GBM)] using cDNA microarrays containing 18,981 genes. Several of the markers identified were also validated by real-time reverse transcription quantitative PCR and immunohistochemical analysis on an independent set of tumor samples (n = 100). Survival analysis was carried out for two markers on another independent set of retrospective cases (n = 51). RESULTS: We identified several differentially regulated grade-specific genes. Independent validation by real-time reverse transcription quantitative PCR analysis found growth arrest and DNA-damage-inducible alpha (GADD45alpha) and follistatin-like 1 (FSTL1) to be up-regulated in most GBMs (both primary and secondary), whereas superoxide dismutase 2 and adipocyte enhancer binding protein 1 were up-regulated in the majority of primary GBM. Further, identification of the grade-specific expression of GADD45alpha and FSTL1 by immunohistochemical staining reinforced our findings. Analysis of retrospective GBM cases with known survival data revealed that cytoplasmic overexpression of GADD45alpha conferred better survival while the coexpression of FSTL1 with p53 was associated with poor survival. CONCLUSIONS: Our study reveals that GADD45alpha and FSTLI are GBM-specific whereas superoxide dismutase 2 and adipocyte enhancer binding protein 1 are primary GBM-specific diagnostic markers. Whereas GADD45alpha overexpression confers a favorable prognosis, FSTL1 overexpression is a hallmark of poor prognosis in GBM patients.

• PBEF1/NAmPRTase/Visfatin: a potential malignant astrocytoma/glioblastoma serum marker with prognostic value.

  Authors: P Sreekanth Reddy, Srikantha Umesh, Balaram Thota, Ashwani Tandon, Paritosh Pandey, A S Hegde, Anandh Balasubramaniam, B A Chandramouli, Vani Santosh, M R S Rao, Paturu Kondaiah, Kumaravel Somasundaram

  Cancer biology & therapy. 06/2008; 7(5):663-8.

  Malignant astrocytomas comprise anaplastic astrocytoma (AA; grade III) and Glioblastoma (GBM; grade IV). GBM is the most malignant with a median survival of 10-12 months in patients. Using cDNAMalignant astrocytomas comprise anaplastic astrocytoma (AA; grade III) and Glioblastoma (GBM; grade IV). GBM is the most malignant with a median survival of 10-12 months in patients. Using cDNA microarray based expression profiling of different grades of astrocytomas, we identified several fold increased levels of PBEF1 transcripts in GBM samples. Pre-B-cell colony enhancing factor 1 gene (PBEF1) encodes Nicotinamide phosphoribosyltransferase (NAmPRTase), which catalyses the rate limiting step in the salvage pathway of NAD metabolism in mammalian cells. Further validation using real time RT-qPCR on an independent set of tumor samples (n=91) and normal brain samples (n=9), GBM specific higher expression of PBEF1 was confirmed. Immunohistochemical staining for PBEF1 on a subset of the above samples largely reinforced our finding. We carried out ELISA analysis on serum samples of astrocytoma patients to determine whether this protein levels would correlate with the presence of tumor and tumor grade. PBEF1 serum levels were substantially elevated in many of the AA and GBM patients. Statistical analysis of these data indicates that in patients with astrocytoma, serum PBEF1 levels correlate with tumor grade and is highest in GBM. Immunohistochemical analysis of an independent set of 51 retrospective GBM cases with known survival data revealed that PBEF1 expression in the tumor tissue along with its co-expression with p53 was associated with poor survival. Thus, we have identified PBEF1 as a potential malignant astrocytoma serum marker and prognostic indicator among GBMs.

• Safe and efficient gene therapy--delivery makes all the difference.

  Authors: Ramaswamy Suvasini, Kumaravel Somasundaram

  Cancer biology & therapy. 03/2008; 7(2):225-7.

• Mixed ligand ruthenium(II) complexes of bis(pyrid-2-yl)-/bis(benzimidazol-2-yl)-dithioether and diimines: study of non-covalent DNA binding and cytotoxicity.

  Authors: Venugopal Rajendiran, Mariappan Murali, Eringathodi Suresh, Sarika Sinha, Kumaravel Somasundaram, Mallayan Palaniandavar

  Dalton transactions (Cambridge, England : 2003). 02/2008;

  A series of mixed ligand ruthenium(II) complexes [Ru(pdto)(diimine)](ClO4)2/(PF6)2 1-3 and [Ru(bbdo)(diimine)](ClO4), 4-6, where pdto is 1,8-bis(pyrid-2-yl)-3,6-dithiooctane, bbdo isA series of mixed ligand ruthenium(II) complexes [Ru(pdto)(diimine)](ClO4)2/(PF6)2 1-3 and [Ru(bbdo)(diimine)](ClO4), 4-6, where pdto is 1,8-bis(pyrid-2-yl)-3,6-dithiooctane, bbdo is 1,8-bis(benzimidazol-2-yl)-3,6-dithiooctane and diimine is 1,10-phenanthroline (phen), dipyrido-[3,2-d:2',3'-f]-quinoxaline (dpq) and dipyrido[3,2-a:2',3'-c]phenazine (dppz), have been isolated and characterised by analytical and spectral methods. The complexes [Ru(pdto)(phen)](PF6)2 la, [Ru(pdto)(dpq)(Cl](PF6) 2a, [Ru(bbdo)(phen)](PF6)2 4a and [Ru(bbdo)(dpq)](ClO4)2 5 have been structurally characterized and their coordination geometries around ruthenium(II) are described as distorted octahedral. In la, 4a and 5 the two thioether sulfur and two py/bzim nitrogen atoms of the tetradentate pdto/bbdo ligand are folded around Ru(II) to give predominantly a "cis-alpha" configuration. (I)H NMR spectral data of the complexes support this configuration in solution. In [Ru(pdto)(dpq)Cl](PF6) 2a with a distorted octahedral coordination geometry, one of the two py nitrogens of pdto is not coordinated. The DNA binding constants (Kb: 2, 2.00 +/- 0.02 x 10(4) M(-1), s = 1.0; 3, 3.00 +/- 0.01 x 10(6) M(-1), s = 1.3) determined by absorption spectral titrations of the complexes with CT DNA reveal that 3 interacts with DNA more tightly than 2 through partial intercalation of the extended planar ring of coordinated dppz with the DNA base stack. The DNA binding affinities of the complexes increase with increase in the number of planar aromatic rings in the co-ligand, and on replacing both the py moieties in pdto complexes (1-3) by bzim moieties to give bbdo complexes (4-6). Upon interaction with CT DNA the complexes 1, 2, 5 and 6 show a decrease in anodic current in the cyclic voltammograms. On the other hand, interestingly, 3 and 4 show an increase in anodic current suggesting their involvement in electrocatalytic guanine oxidation. Interestingly, of all the complexes, only 6 alters the superhelicity of DNA upon binding with supercoiled pBR322 DNA. The cytotoxicities of the dppz complexes 3 and 6, which avidly bind to DNA, have been examined by screening them against cell lines of different cancer origins. It is noteworthy that 6 exhibits selectivity with higher cytotoxicity against the melanoma cancer cell line (A375) than other cell lines, potency approximately twice that of cisplatin and toxicity to normal cells 3 and 90 times less than cisplatin and adriamycin respectively.