Gupta M.K.,Center for Cellular and Molecular Biology |
Gupta M.K.,Institute of Bioinformatics International Technology Park |
Polisetty R.V.,Center for Cellular and Molecular Biology |
Polisetty R.V.,Institute of Bioinformatics International Technology Park |
And 7 more authors.
Glioblastoma multiforme (GBM) is the most common and aggressive type of primary malignant tumor of the central nervous system. We have carried out a deep analysis of the secretome of a rapidly proliferating and tumorigenic cell line HNGC-2, representing GBM, in an effort to identify proteins, which may be targeted in the plasma of GBM patients as markers for diagnosis and disease surveillance. Prefractionation of the proteins from the conditioned medium of HNGC-2 cells in SDS gels followed by LC-MS/MS analysis using an ESI-IT mass spectrometer (LTQ) led to a total of 996 protein identifications with ≥2 peptides each. Of them, 664 proteins were observed in the transcriptome of HNGC-2 cells. The dataset of 996 proteins was mapped to important functional groups, such as cellular assembly and organisation, DNA recombination and repair, and other classes. Actin cytoskeleton signalling, phosphatidyl inositol 3 kinase (PI3K/AKT) and integrin linked kinase (ILK) signalling pathways were seen as enriched pathways. Comparisons with the published secretome of cell lines from 12 different cancers, including GBM, revealed that 348 proteins shared a commonality with a secretome of at least one other cell line, 321 of which were found to contain signal sequences or transmembrane domains and 335 could be linked to a plasma membrane or extracellular localization. Through intergration of this data we arrived at a non-redundant list of 597 protein identifications with the potential for secretion either by classical secretory pathways or by non-secretory processes; 233 of them have been detected in cerebrospinal fluid or plasma as per the published literature, and 172 have been implicated in GBM or other cancers. The HNGC-2 secretome dataset could serve as a useful resource for designing a targeted investigation of GBM biomarkers in plasma. © 2013 The Royal Society of Chemistry. Source
Sahu A.,Institute of Bioinformatics International Technology Park |
Sahu A.,Pondicherry University |
Kumar S.,Institute of Bioinformatics International Technology Park |
Sreenivasamurthy S.K.,Institute of Bioinformatics International Technology Park |
And 25 more authors.
Background: Toxoplasma encephalitis is caused by the opportunistic protozoan parasite Toxoplasma gondii. Primary infection with T. gondii in immunocompetent individuals remains largely asymptomatic. In contrast, in immunocompromised individuals, reactivation of the parasite results in severe complications and mortality. Molecular changes at the protein level in the host central nervous system and proteins associated with pathogenesis of toxoplasma encephalitis are largely unexplored. We used a global quantitative proteomic strategy to identify differentially regulated proteins and affected molecular networks in the human host during T. gondii infection with HIV co-infection. Results: We identified 3,496 proteins out of which 607 proteins were differentially expressed (≥1.5-fold) when frontal lobe of the brain from patients diagnosed with toxoplasma encephalitis was compared to control brain tissues. We validated differential expression of 3 proteins through immunohistochemistry, which was confirmed to be consistent with mass spectrometry analysis. Pathway analysis of differentially expressed proteins indicated deregulation of several pathways involved in antigen processing, immune response, neuronal growth, neurotransmitter transport and energy metabolism. Conclusions: Global quantitative proteomic approach adopted in this study generated a comparative proteome profile of brain tissues from toxoplasma encephalitis patients co-infected with HIV. Differentially expressed proteins include previously reported and several new proteins in the context of T. gondii and HIV infection, which can be further investigated. Molecular pathways identified to be associated with the disease should enhance our understanding of pathogenesis in toxoplasma encephalitis. © 2014 Sahu et al.; licensee BioMed Central Ltd. Source