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Background Early diagnosis is important for the timely treatment of gallbladder carcinoma (GBC) patients and may lead to increased survival outcomes. Here, we have applied serological proteome analysis (SERPA), an immunoproteomics approach, for the detection of ‘tumor-associated antigens (TAAs) that elicit humoral response’ in early stage GBC patients. Methods Total protein from pooled tumor tissue of GBC patients (n = 7) was resolved by two-dimensional gel electrophoresis (2-DE) followed by immunoblotting using pooled blood plasma from healthy volunteers (n = 11) or gallstone disease (GSD) cases (n = 11) or early stage GBC (Stage I and II) (n = 5) or GBC stage IIIA (n = 9). 2-D gel and immunoblot images were acquired and analyzed using PDQuest software to identify immunoreactive spots in GBC cases in comparison to controls. Proteins from immunoreactive spots were identified by liquid chromatography- tandem mass spectrometric analysis (LC-MS/MS). Autoantibody levels for two of the functionally relevant proteins were investigated in individual plasma samples (52 cases and 89 controls) by dot blot assay using recombinant proteins. Results Image analysis using PDQuest software identified 25 protein spots with significantly high or specific immunoreactivity in GBC cases. Mass spectrometric analysis of 8 corresponding protein spots showing intense immunoreactivity (based on densitometric analysis) in early stage GBC or GBC stage IIIA cases led to the identification of 27 proteins. Some of the identified proteins include ANXA1, HSPD1, CA1, CA2, ALDOA and CTSD. Among the two proteins, namely ANXA1 and HSPD1 verified using a cohort of samples, significantly elevated autoantibody levels against ANXA1 were observed in early stage GBC cases in comparison to healthy volunteers or GSD cases (unpaired t-test, p Conclusions The study suggests that the ANXA1 autoantibody levels against ANXA1 may be potentially employed for early stage detection of GBC patients. Other proteins could also be explored and verified in a large cohort of clinical samples.

Estrogen insufficiency at menopause cause accelerated bone loss due to unwarranted differentiation and function of osteoclasts. Unraveling the underlying mechanism/s may identify mediators of estrogen action which can be targeted for improved management of osteoporosis. Towards this, we analyzed the effect of 17β-estradiol on the proteomes of differentiating human osteoclasts. The major proteomic changes observed included upregulation of LYN by estrogen. We, therefore, investigated the effect of estrogen on osteoclast differentiation, survival, and function in control and LYN knockdown conditions. In control condition, estrogen treatment increased the apoptosis rate and suppressed the calcium signaling by reducing the intracellular Ca2+ levels as well as expression and activation of NFATc1 and c-Src during differentiation, resulting in reduced osteoclastogenesis. These osteoclasts were smaller in size with reduced extent of multinuclearity and produced significantly low levels of bone resorbing enzymes. They also exhibited disrupted sealing zone formation with low podosome density, impaired cell polarization and reduced resorption of dentine slices. Interestingly, in LYN knockdown condition, estrogen failed to induce apoptosis and inhibit activation of NFATc1 and c-Src. Compared to effect of estrogen on osteoclast in control condition, LYN knockdown osteoclasts did not show reduction in production of bone resorbing enzymes and had defined sealing zone formation with high podosome density with no impairment in cell polarization. They resorbed significant area on dentine slices. Thus, the inhibitory action of estrogen on osteoclast was severely restrained in LYN knockdown condition, demonstrating the importance of LYN as a key mediator of the effect of estrogen on osteoclastogenesis.

We have carried out proteogenomic analysis of the breast cancer transcriptomic and proteomic data, available at The Clinical Proteomic Tumor Analysis Consortium resource, to identify novel peptides arising from alternatively spliced events as well as other noncanonical expressions. We used a pipeline that consisted of de novo transcript assembly, six frame-translated custom database, and a combination of search engines to identify novel peptides. A portfolio of 4,387 novel peptide sequences initially identified was further screened through PepQuery validation tool (Clinical Proteomic Tumor Analysis Consortium), which yielded 1,558 novel peptides. We considered the dataset of 1,558 validated through PepQuery to understand their functional and clinical significance, leaving the rest to be further verified using other validation tools and approaches. The novel peptides mapped to the known gene sequences as well as to genomic regions yet undefined for translation, 580 novel peptides mapped to known protein-coding genes, 147 to non-protein-coding genes, and 831 belonged to novel translational sequences. The novel peptides belonging to protein-coding genes represented alternatively spliced events or 5' or 3' extensions, whereas others represented translation from pseudogenes, long noncoding RNAs, or novel peptides originating from uncharacterized protein-coding sequences-mostly from the intronic regions of known genes. Seventy-six of the 580 protein-coding genes were associated with cancer hallmark genes, which included key oncogenes, transcription factors, kinases, and cell surface receptors. Survival association analysis of the 76 novel peptide sequences revealed 10 of them to be significant, and we present a panel of six novel peptides, whose high expression was found to be strongly associated with poor survival of patients with human epidermal growth factor receptor 2-enriched subtype. Our analysis represents a landscape of novel peptides of different types that may be expressed in breast cancer tissues, whereas their presence in full-length functional proteins needs further investigations.

Background Gonadotropin-releasing hormone (GnRH) receptor, a rhodopsin-like G-protein coupled receptor (GPCR) family member involved in GnRH signaling, is reported to be expressed in several tumors including glioblastoma multiforme (GBM), one of the most malignant and aggressive forms of primary brain tumors. However, the molecular targets associated with GnRH receptor are not well studied in GBM or in other cancers. The present study aims at investigating the effect of GnRH agonist (Gosarelin acetate) on cell proliferation and associated signaling pathways in GBM cell line, LN229. Methods LN229 cells were treated with different concentrations of GnRH agonist (10−10 M to 10−5 M) and the effect on cell proliferation was analyzed by cell count method. Further, total protein was extracted from control and GnRH agonist treated cells (with maximum reduction in cell proliferation) followed by trypsin digestion, labeling with iTRAQ reagents and LC-MS/MS analysis to identify differentially expressed proteins. Bioinformatic analysis was performed for annotation of proteins for the associated molecular function, altered pathways and network analysis using STRING database. Results The treatment with different concentrations of GnRH agonist showed a reduction in cell proliferation with a maximum reduction of 48.2% observed at 10−6 M. Quantitative proteomic analysis after GnRH agonist treatment (10−6 M) led to the identification of a total of 29 differentially expressed proteins with 1.3-fold change (23 upregulated, such as, kininogen-1 (KNG1), alpha-2-HS-glycoprotein (AHSG), alpha-fetoprotein (AFP), and 6 downregulated, such as integrator complex subunit 11 (CPSF3L), protein FRG1 (FRG1). Some of them are known [KNG1, AHSG, AFP] while others such as inter-alpha-trypsin inhibitor heavy chain H2 (ITIH2), ITIH4, and LIM domain-containing protein 1 (LIMD1) are novel to GnRH signaling pathway. Protein-protein interaction analysis showed a direct interaction of KNG1, a hub molecule, with GnRH, GnRH receptor, EGFR and other interactors including ITIH2, ITIH4 and AHSG. Overexpression of KNG1 after GnRH agonist treatment was validated using Western blot analysis, while a significant inhibition of EGFR was observed after GnRH agonist treatment. Conclusions The study suggests a possible link of GnRH signaling with EGFR signaling pathways likely via KNG1. KNG1 inhibitors may be investigated independently or in combination with GnRH agonist for therapeutic applications.

Data Availability Statement: The datasets presented in this study can be found in online repositories. The names of the repositories and accession number(s) can be found in the article/Supplementary Material (https://www.frontiersin.org/articles/10.3389/fimmu.2020.600660/full#h11). Copyright © 2021 Thakur, Sathe, Kundu, Biswas, Gautam, Alkahtani, Idicula-Thomas, Sirdeshmukh, Kishore and Madan. Surfactant protein-D (SP-D), a member of the collectin family has been shown to induce apoptosis in cancer cells. SP-D is composed of an N-terminal collagen-like domain and a calcium-dependent carbohydrate recognition domain (CRD). Recently, we reported that a recombinant fragment of human SP-D (rfhSP-D), composed of homotrimeric CRD region, induced intrinsic apoptotic pathway in prostate cancer cells. Here, we analyzed the membrane interactome of rfhSP-D in an androgen-independent prostate cancer cell line, PC3, by high resolution mass spectrometry and identified 347 proteins. Computational analysis of PPI network of this interactome in the context of prostate cancer metastasis and apoptosis revealed Glucose Regulated Protein of 78 kDa (GRP78) as an important binding partner of rfhSP-D. Docking studies suggested that rfhSP-D (CRD) bound to the substrate-binding domain of glycosylated GRP78. This was further supported by the observations that human recombinant GRP78 interfered with the binding of rfhSP-D to anti-SP-D polyclonal antibodies; GRP78 also significantly inhibited the binding of recombinant full-length human SP-D with a monoclonal antibody specific to the CRD in a dose-dependent manner. We conclude that the interaction with rfhSP-D is likely to interfere with the pro-survival signaling of GRP78. ICMR- National Institute for Research in Reproductive Health ICMR-NIRRH (Accession no. 921); ICMR- National Institute for Research in Reproductive Health ICMR-NIRRH-JRF; ICMR- National Institute for Research in Reproductive Health ICMR-SRF; Researchers Supporting Project (RSP-2020/26) King Saud University, Riyadh.

GPR56/ADGRG1 is a member of the adhesion G-protein coupled receptor (aGPCR) family and one of the important players in the normal development of the brain. It plays a pivotal role in the diverse neurobiological processes, including cortical formation, oligodendrocyte development, and myelination. Mutations in GPR56 are known to cause brain malformation, myelination defects and are also implied in many cancers, including brain tumors. Since its identification almost two decades ago, GPR56 has emerged from an orphaned and uncharacterized GPCR to an increasingly well studied receptor. Yet, much needs to be understood about GPR56, both in terms of its molecular interactions and biological functions that may be relevant in normal health and disease. The review is focussed on the recent available knowledge of GPR56, which would give useful insights into its known and potential roles in the human brain, neurological disorders, and brain tumors like glioblastoma.

Splice variants are known to be important in the pathophysiology of tumors, including the brain cancers. We applied a proteogenomics pipeline to identify splice variants in glioblastoma (GBM, grade IV glioma), a highly malignant brain tumor, using in-house generated mass spectrometric proteomic data and public domain RNASeq dataset. Our analysis led to the identification of a novel exon that maps to the long isoform of Neural cell adhesion molecule 1 (NCAM1), expressed on the surface of glial cells and neurons, important for cell adhesion and cell signaling. The presence of the novel exon is supported with the identification of five peptides spanning it. Additional peptides were also detected in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gel separated proteins from GBM patient tissue, underscoring the presence of the novel peptides in the intact brain protein. The novel exon was detected in the RNASeq dataset in 18 of 25 GBM samples and separately validated in additional 10 GBM tumor tissues using quantitative real-time-polymerase chain reaction (qRT-PCR). Both transcriptomic and proteomic data indicate downregulation of NCAM1, including the novel variant, in GBM. Domain analysis of the novel NCAM1 sequence indicates that the insertion of the novel exon contributes extra low-complexity region in the protein that may be important for protein-protein interactions and hence for cell signaling associated with tumor development. Taken together, the novel NCAM1 variant reported in this study exemplifies the importance of future multiomics research and systems biology applications in GBM.

Glioblastoma multiforme (GBM) is one of the most lethal brain tumors with an inadequately understood pathophysiology. Biomarkers that guide accurate diagnosis and treatment decisions would greatly support precision medicine for GBM. Previous studies of GBM have focused on signaling pathways such as epidermal growth factor receptor (EGFR), platelet-derived growth factor receptors (PDGFRs), notch, wnt, and others, identified with single omics technology platforms (genomics, transcriptomics, or proteomics), but not with their integrated use. In this context, we report here a multi-omics pathway view, expanded through integration of the expression data at transcriptomic and proteomic levels, followed by selection of a functionally related group of proteins such as kinases deregulated in GBM. By using this strategy, we observed a highly significant enrichment of the gonadotropin-releasing hormone (GnRH) signaling pathway that was not deciphered with single omics datasets. The curation of the GnRH pathway with extensive literature analysis brought about a comprehensive annotation of the pathway, which included several additional pathway members that were not previously annotated. A targeted search resulted in identification of additional nonkinase members of the pathway in the GBM multi-omics datasets. We found evidence of GnRH receptor expression in GBM and other cancers. We offer here an updated generic pathway map of GnRH signaling, show its enrichment in the context of GBM, and discuss its plausible cross-connectivity with EGFR, wnt, calcium, and focal adhesion kinase signaling pathways that were earlier shown to be the top deregulated pathways in GBM. In conclusion, this study demonstrates the promise of multi-omics research and analyses to better understand complex cancers and suggests continued efforts and research in this direction in the field of integrative biology.

Dysplastic leukoplakia (LP) of the oral cavity is a potentially malignant condition for oral squamous cell carcinoma (OSCC), early detection of which remains an unmet clinical need. In an effort to develop non-invasive biomarker based method for early detection of the disease, differential proteomic profiling was carried out with the saliva from patients with risk habits and diagnosed with LP and those with lymph node negative and positive OSCC in comparison to healthy controls with risk habits. Ninety three proteins were observed at elevated level (≥1.5 fold), and 30 were prioritized based on a scoring system comprising of confidence of identification, presence in the various specimen groups, functional relevance, and their secretory potential. Verification was carried out in independent patient cohorts for 8 selected, representative, upregulated proteins using ELISA. Three of them CD44, S100A7, and S100P were significantly altered in patients with LP as well as OSCC and can be regarded as a panel of biomarker candidates for early detection of the malignancy. Other members may also be investigated in a targeted manner to expand the portfolio of biomarkers for early detection. The mass spectrometry data are available via ProteomeXchange with identifier PXD015722. SIGNIFICANCE: There is an unmet clinical need for non-invasive, biomarker based methods for the improved early detection and the subsequent management of oral cancer. The study represents differential proteome profiling of the saliva of patients with oral dysplastic leukoplakia (LP) - a potentially malignant lesion, patients diagnosed with oral squamous cell carcinoma (OSCC), and healthy controls to identify potential markers for the purpose of early detection of malignancy. From among the matched and prioritized proteins with elevated levels in the saliva of patients with LP and those with OSCC, eight were verified. Three of them - CD44, S100A7 and S100P appeared promising candidates as biomarkers for early detection of the neoplastic predisposition and may form the basis of clinical assays for this purpose.

Proteins present in human saliva offer an immense potential for clinical applications. However, exploring salivary proteome is technically challenged due to the presence of amylase and albumin in high abundance. In this study, we used four workflows to analyze human saliva from healthy individuals which involved depletion of abundant proteins using affinity-based separation methods followed by protein or peptide fractionation and high resolution mass spectrometry analysis. We identified a total of 1256 human salivary proteins, 292 of them being reported for the first time. All identifications were verified for any shared proteins/peptides from the salivary microbiome that may conflict with the human protein identifications. On integration of our results with the analyses reported earlier, we arrived at an updated human salivary proteome containing 3449 proteins, 808 of them have been reported as differentially expressed proteins in oral cancer tissues. The secretory nature of 598 of the 808 proteins has also been supported on the basis of the presence of signal sequence, transmembrane domain or association with exosomes. From this subset, we provide a priority list of 139 proteins along with their proteotypic peptides, which may serve as a reference for targeted investigations as secretory markers for clinical applications in oral malignancies. This article is part of a Special Issue entitled: Proteomics in India.

Salivary proteins are an important source for developing marker-based assays for oral cancers. To get an insight into the proteins present in human saliva, we applied multiple strategies involving affinity-based depletion of abundant proteins, fractionation of the resulting proteins or their tryptic peptides followed by LC–MS/MS analysis, using high resolution mass spectrometry. By integrating the protein identifications observed by us with those from similar workflows employed in earlier investigations, we compiled an updated salivary proteome. We have mapped the salivary proteome to the published data on differentially expressed proteins from oral cancer tissues and also for their secretory features using prediction tools, SignalP 4.1, TMHMM 2c and Exocarta. Proteotypic peptides for the subset of proteins implicated in oral cancer and mapped to any two of the prediction tools for secretory potential have been listed. The data here are related to the research article “Human saliva proteome – a resource of potential biomarkers for oral cancer” in the Journal of Proteomics [1].

Glioblastoma multiforme (GBM) is one of the most aggressive and lethal forms of the primary brain tumors. With predominance of tumor heterogeneity and emergence of new subtypes, new approaches are needed to develop tissue-based markers for tumor typing or circulatory markers to serve as blood-based assays. Multi-omics data integration for GBM tissues would offer new insights on the molecular view of GBM pathogenesis useful to identify biomarker panels. On the other hand, mapping differentially expressed tissue proteins for their secretory potential through bioinformatics analysis or analysis of the tumor cell secretome or tumor exosomes would enhance our understanding of the tumor microenvironment and prospects for targeting circulatory biomarkers. In this review, the authors first present potential biomarker candidates for GBM that have been reported and then focus on plausible pipelines for multi-omic data integration to identify additional, high-confidence molecular panels for clinical applications in GBM.

In line with the aims of the Chromosome-centric Human Proteome Project (C-HPP) to completely annotate proteins of each chromosome and biology/disease driven HPP (B/D-HPP) to decipher their relation to diseases, we have generated a nonredundant catalogue of protein-coding genes for Chromosome 12 (Chr. 12) and further annotated proteins associated with major neurological disorders. Integrating high level proteomic evidence from four major databases (neXtProt, Global Proteome Machine (GPMdb), PeptideAtlas, and Human Protein Atlas (HPA)) along with Ensembl data resource resulted in the identification of 1066 protein coding genes, of which 171 were defined as "missing proteins" based on the weak or complete absence of experimental evidence. With functional annotations using DAVID and GAD, about 40% of the proteins could be grouped as brain related with implications in cancer or neurological disorders. We used published and unpublished high confidence mass spectrometry data from our group and other literature consisting of more than 5000 proteins derived from clinical specimens from patients with human gliomas, Alzheimer's disease, and Parkinson's disease and mapped it onto Chr. 12. We observed a total of 202 proteins mapping to human Chr. 12, 136 of which were differentially expressed in these disease conditions as compared to the normal. Functional grouping indicated their association with cell cycle, cell-to-cell signaling, and other important processes and networks, whereas their disease association analysis confirmed neurological diseases and cancer as the major group along with psycological disorders, with several overexpressed genes/proteins mapping to 12q13-15 amplicon region. Using multiple strategies and bioinformatics tools, we identified 103 differentially expressed proteins to have secretory potential, 17 of which have already been reported in direct analysis of the plasma or cerebrospinal fluid (CSF) from the patients and 21 of them mapped to cancer associated protein (CAPs) database that are amenable to selective reaction monitoring (SRM) assays for targeted proteomic analysis. Our analysis also reveals, for the first time, mass spectrometric evidence for two "missing proteins" from Chr. 12, namely, synaptic vesicle 2-related protein (SVOP) and IQ motif containing D (IQCD). The analysis provides a snapshot of Chr. 12 encoded proteins associated with gliomas and major neurological conditions and their secretability which can be used to drive efforts for clinical applications.

Pancreatic cancer is the fourth leading cause of cancer-related death in the world. The etiology of pancreatic cancer is heterogeneous with a wide range of alterations that have already been reported at the level of the genome, transcriptome, and proteome. The past decade has witnessed a large number of experimental studies using high-throughput technology platforms to identify genes whose expression at the transcript or protein levels is altered in pancreatic cancer. Based on expression studies, a number of molecules have also been proposed as potential biomarkers for diagnosis and prognosis of this deadly cancer. Currently, there are no repositories which provide an integrative view of multiple Omics data sets from published research on pancreatic cancer. Here, we describe the development of a web-based resource, Pancreatic Cancer Database (http://www.pancreaticcancerdatabase.org), as a unified platform for pancreatic cancer research. PCD contains manually curated information pertaining to quantitative alterations in miRNA, mRNA, and proteins obtained from small-scale as well as high-throughput studies of pancreatic cancer tissues and cell lines. We believe that PCD will serve as an integrative platform for scientific community involved in pancreatic cancer research.

The availability of human genome sequence has transformed biomedical research over the past decade. However, an equivalent map for the human proteome with direct measurements of proteins and peptides does not exist yet. Here we present a draft map of the human proteome using high-resolution Fourier-transform mass spectrometry. In-depth proteomic profiling of 30 histologically normal human samples, including 17 adult tissues, 7 fetal tissues and 6 purified primary haematopoietic cells, resulted in identification of proteins encoded by 17,294 genes accounting for approximately 84% of the total annotated protein-coding genes in humans. A unique and comprehensive strategy for proteogenomic analysis enabled us to discover a number of novel protein-coding regions, which includes translated pseudogenes, non-coding RNAs and upstream open reading frames. This large human proteome catalogue (available as an interactive web-based resource at http://www.humanproteomemap.org) will complement available human genome and transcriptome data to accelerate biomedical research in health and disease.

Plasma Proteome Database (PPD; http://www.plasmaproteomedatabase.org/) was initially described in the year 2005 as a part of Human Proteome Organization's (HUPO's) pilot initiative on Human Plasma Proteome Project. Since then, improvements in proteomic technologies and increased throughput have led to identification of a large number of novel plasma proteins. To keep up with this increase in data, we have significantly enriched the proteomic information in PPD. This database currently contains information on 10,546 proteins detected in serum/plasma of which 3784 have been reported in two or more studies. The latest version of the database also incorporates mass spectrometry-derived data including experimentally verified proteotypic peptides used for multiple reaction monitoring assays. Other novel features include published plasma/serum concentrations for 1278 proteins along with a separate category of plasma-derived extracellular vesicle proteins. As plasma proteins have become a major thrust in the field of biomarkers, we have enabled a batch-based query designated Plasma Proteome Explorer, which will permit the users in screening a list of proteins or peptides against known plasma proteins to assess novelty of their data set. We believe that PPD will facilitate both clinical and basic research by serving as a comprehensive reference of plasma proteins in humans and accelerate biomarker discovery and translation efforts.

Sample processing protocols that enable compatible recovery of differentially expressed (DE) transcripts and proteins are necessary for integration of the multiomics data applied in the analysis of tumors. In this pilot study, we compared two different isolation methods for extracting RNA and protein from laryngo-pharyngeal tumor tissues and the corresponding adjacent normal sections. In Method 1, RNA and protein were isolated from a single tissue section sequentially and in Method 2, the extraction was carried out using two different sections and two independent and parallel protocols for RNA and protein. RNA and protein from both methods were subjected to RNA-seq and iTRAQ-based LC-MS/MS analysis, respectively. Analysis of data revealed that a higher number of differentially expressed transcripts and proteins were concordant in their regulation trends in Method 1 as compared to Method 2. Cross method comparison of concordant entities revealed that RNA and protein extraction from the same tissue section (Method 1) recovered more concordant entities that are missed in the other extraction method (Method 2) indicating heterogeneity in distribution of these entities in different tissue sections. Method 1 could thus be the method of choice for integrated analysis of transcriptome and proteome data. This article is protected by copyright. All rights reserved

Diffuse astrocytoma (DA; WHO grade II) is a low-grade, primary brain neoplasm with high potential of recurrence as higher grade malignant form. We have analyzed differentially expressed membrane proteins from these tumors, using high-resolution mass spectrometry. A total of 2803 proteins were identified, 340 of them differentially expressed with minimum of 2 fold change and based on ≥2 unique peptides. Bioinformatics analysis of this dataset also revealed important molecular networks and pathways relevant to tumorigenesis, mTOR signaling pathway being a major pathway identified. Comparison of 340 differentially expressed proteins with the transcript data from Grade II diffuse astrocytomas reported earlier, revealed about 190 of the proteins correlate in their trends in expression. Considering progressive and recurrent nature of these tumors, we have mapped the differentially expressed proteins for their secretory potential, integrated the resulting list with similar list of proteins from anaplastic astrocytoma (WHO Grade III) tumors and provide a panel of proteins along with their proteotypic peptides, as a resource that would be useful for investigation as circulatory plasma markers for post-treatment surveillance of DA patients.

Aspergillus fumigatus (A. fumigatus) is a medically important opportunistic fungus that may lead to invasive aspergillosis in humans with weak immune system. Proteomic profiling of this fungus on exposure to itraconazole (ITC), an azole antifungal drug, may lead to identification of its molecular targets and better understanding on the development of drug resistance against ITC in A. fumigatus. Here, proteome analysis was performed using 2-DE followed by mass spectrometric analysis which resulted in identification of a total of 259 unique proteins. Further, proteome profiling of A. fumigatus was carried out on exposure to ITC, 0.154 μg/ml, the minimum inhibitory concentration (MIC50). Image analysis showed altered levels of 175 proteins (66 upregulated and 109 downregulated) of A. fumigatus treated with ITC as compared to the untreated control. Peptide mass fingerprinting led to the identification of 54 proteins (12 up-regulated and 42 down-regulated). The differentially expressed proteins include proteins related to cell stress, carbohydrate metabolism and amino acid metabolism. We also observed four proteins, including nucleotide phosphate kinase (NDK), that are reported to interact with calcineurin, a protein involved in regulation of cell morphology and fungal virulence. Comparison of differentially expressed proteins on exposure to ITC with artemisinin (ART), an antimalarial drug with antifungal activity(1), revealed a total of 26 proteins to be common among them suggesting that common proteins and pathways are targeted by these two antifungal agents. The proteins targeted by ITC may serve as important leads for development of new antifungal drugs.

Glioblastoma multiforme (GBM), the most aggressive primary brain tumor, is characterized by high rates of cell proliferation, migration, and invasion. New therapeutic strategies and targets are being continuously explored with the hope for better outcome. By overlaying transcriptomic and proteomic data from GBM clinical tissues, we identified 317 differentially expressed proteins to be concordant with the messenger RNAs (mRNAs). We used these entities to generate integrated regulatory information at the level of microRNAs (miRNAs) and their mRNA and protein targets using prediction programs or experimentally verified miRNA target mode in the miRWalk database. We observed 60% or even more of the miRNA-target pairs to be consistent with experimentally observed inverse expression of these molecules in GBM. The integrated view of these regulatory cascades in the contexts of cell proliferation and invasion networks revealed two-dimensional molecular interactions with regulatory and functional linkages (miRNAs and their mRNA-protein targets in one dimension; multiple miRNAs associated in a functional network in the second dimension). A total of 28 of the 35 differentially expressed concordant mRNA-protein entities represented in the proliferation network, and 51 of the 59 such entities represented in the invasion network, mapped to altered miRNAs from GBM and conformed to an inverse relationship in their expression. We believe the two-dimensional maps of gene expression changes enhance the strength of the discovery datasets derived from omics-based studies for their applications in GBM as well as tumors in general.

Alkaline-stable β-amylase (EC 3.2.1.2) was purified to apparent homogeneity from malted African finger millet ( Eleusine coracana ) seed by ammonium sulfate fractionation and anion exchange and affinity chromatographies. Gel filtration chromatography together with SDS-PAGE revealed that the enzyme is monomeric, with a molecular weight of 59.1 kDa. It has a pI value of 5.2 and is optimally active at pH 5.0 and 50 °C. 2DE-MS isolated and identified two isoforms of the enzyme with unique amino acid sequences. The purified enzyme was highly selective for soluble potato starch, amylose and amylopectin, and α-cyclodextrin was shown to be a competitive inhibitor with a Gibbs free energy (Δ G °′) of binding of 18.11 kJ/mol. The enzyme was stable at a pH range of 4.0–10.0 and temperature range of 30–70 °C. It was irreversibly inactivated by heating to 60 °C and 70 °C, which was often related to aggregation. The apparent K M of the enzyme for p-nitrophenyl maltopentaoside (PPNG-5) was 2.1 mM. NH 4 + , Hg 2+ , Al 3+ , EDTA, ascorbic acid, iodoacetamide, iodoacetic acid and gibberellic acid all inhibited the enzyme. The enzyme unfolded after treatment with 4.0 M guanidine–HCl and regained 68% of its original activity upon dilution at 4 °C in the presence of 5 mM trehalose. The kinetic parameters of renaturation were first order. This enzyme could be important in the malting of African finger millet seeds, based on the kinetics and properties reported in this study.

Artemisinin, an antimalarial drug, and its derivatives are reported to have antifungal activity against some fungi. We report its antifungal activity against Aspergillus fumigatus (A. fumigatus), a pathogenic filamentous fungus responsible for allergic and invasive aspergillosis in humans, and its synergistic effect in combination with itraconazole (ITC), an available antifungal drug. In order to identify its molecular targets, we further analyzed transcript and proteomic profiles of the fungus on exposure to the artemisinin. In transcriptomic analysis, a total of 745 genes were observed to be modulated on exposure to artemisinin, and some of them were confirmed by real-time polymerase chain reaction analysis. Proteomic profiles of A. fumigatus treated with artemisinin showed modulation of 175 proteins (66 upregulated and 109 downregulated) as compared to the control. Peptide mass fingerprinting led to the identification of 85 proteins-29 upregulated and 56 downregulated, 65 of which were unique proteins. Consistent with earlier reports of molecular mechanisms of artemisinin and that of other antifungal drugs, we believe that oxidative phosphorylation pathway (64 kDa mitochondrial NADH dehydrogenase), cell wall-associated proteins and enzymes (conidial hydrophobin B protein, cell wall phiA protein, extracellular thaumatin domain protein, 1,3-beta-glucanosyltransferase Gel2) and genes involved in ergosterol biosynthesis (ERG6 and coproporphyrinogen III oxidase, HEM13) are potential targets of artemisinin for further investigations.

ADP-glucose pyrophosphorylase (AGPase) is a key enzyme in starch biosynthesis in plants. The activity, expression and gene sequence of AGPase were studied in grains of five rice cultivars representing different origins to gain insight into their variations in relation to starch accumulation. The varieties were Jaya, GEB24 (indica), BSI 115 (japonica), Mahsuri (indica-japonica derivative) and CoRH2 (hybrid). The grain weight increased in all of them until 20 dpa, although at varying rates. It was relatively steady in Mahsuri, in others there was a steep increase from 10 to 20 days post-anthesis (dpa). The total AGPase activity increased steadily from 5 to 20 dpa in Jaya and GEB24, but dropped after 15 dpa in BSI 115 and CoRH2 while in Mahsuri, it maintained the 10 dpa low level until 20 dpa. The AGPase cDNAs did not show any sequence differences in the five varieties. The transcripts of both sub units of AGPase accumulated comparably during the initial phase of grain development suggesting their coordinated expression and dropped after 15 dpa in all the varieties. On the other hand, AGPase protein level remained unchanged after reaching the maximum in CoRH2 and continued to increase up to 20 dpa in the other four varieties. Thus the drop in the enzyme activity cannot be attributed to changes in the transcript or protein amounts per se. We infer that the drop in activity, its varying levels and varying duration in the varieties studied is likely due to differential stability of the active enzyme protein during grain development and that the extended duration of enzyme activity may contribute to increased grain weight.

HIV-exposed seronegative individuals (HESNs) are persons who remain seronegative despite repeated exposure to HIV, suggesting an in vivo resistance mechanism to HIV. Elucidation of endogenous factors responsible for this phenomenon may aid in the development of new classes of microbicides and therapeutics. The genital mucosal secretions of both men and women are known to contain a spectrum of antimicrobials and immune mediators that may contribute to resistance against HIV-1. Existence of HIV serodiscordant couples is a testimony to mucosal factors in the genital tract that prevent sexual transmission of the virus. We attempted to map such mucosal factors in female genital secretions of the serodiscordant couples in comparison with HIV infected and healthy participants using quantitative proteomics. The cervico vaginal lavage (CVL) samples were collected from three groups of study participants (HIV infected, n=30; Un-infected Controls, n=10; Serodiscordant, n=24). Abundant proteins, albumin and globulins were removed from the pooled samples using multiple affinity removal spin cartridge (Agilent) to enhance the sensitivity of iTRAQ proteomics analysis. Initial analysis identified a total of 135 proteins and associated 497 peptide matches. Serodiscordant females showed significantly down regulated levels of Cornifin A, B and C, Neutrophil gelatinase, myeloperoxidase and eosinophil peroxidase. Cornifins are cross-linked envelope protein of keratinocytes and are upregulated during inflammation. Downregulation of oxidative stress inducing enzymes and cornifins suggests immune-quiescence in serodiscordant females. CVL of these women showed significantly upregulated levels of Mucin 5B, S100A7, Alpha-2-macroglobulin, Cystatin A (protease inhibitor), Lacto-transferrin, SLPI (anti-leukoproteinase inhibitor) and SERPIN G1 (protease inhibitor). Significantly elevated levels of Cystatin B and Elafin in the CVL of serodiscordant females were confirmed by ELISA. These results suggest that HIV resistance against the sexual transmission of HIV is the result of immune-quiescence contributed by two complementary mechanisms: downregulation of immune activators and upregulation of their inhibitors.

Tobacco-related oral cancer is the most common cancer among Indian males, gingivo-buccal complex (GBC) being the most affected subsite due to the habit of chewing tobacco. Proteins from the lysates of microdissected normal and transformed epithelium from clinically well-characterized tissue samples of the GBC were separated by two-dimensional gel electrophoresis to identify differentially expressed proteins. Eleven protein spots showed differential expression, which could withstand the stringency of statistical evaluation. The observations were confirmed with additional tissues. Nine of these differentiators were identified by MS as lactate dehydrogenase B, α-enolase, prohibitin, cathepsin D, apolipoprotein A-I, tumor protein translationally controlled-1, an SFN family protein, 14-3-3σ and tropomyosin. Cluster analysis indicated that these proteins, as a coexpressed set, could distinguish normal and transformed epithelium. Functionally, these differentiator molecules are relevant to the pathways and processes that have been previously implicated in oral carcinogenesis and could therefore be investigated further as a panel of markers for management of cancer of the GBC.

Summary Background Approximately 20% of the world's asthmatics are suffering from Aspergillus fumigatus (Afu)-induced allergies. The characterization of specific IgE-inducing allergens in allergic aspergillosis patients is fundamental for clinical diagnosis and for immunotherapy. Methods Immunoproteomics combined with mass spectrometric analysis was used to identify proteins of third-week culture filtrate (3wcf) potentially responsible for Afu-specific IgE immunoreactivity, using pooled sera from Afu-sensitized asthmatics. Their allergenic potential was also tested against patients with allergic bronchopulmonary aspergillosis (ABPA), by two-dimensional (2-D) gel electrophoresis immunoblotting of 3wcf proteins with individual sera from such patients. This helped us to establish a set of candidate allergens, which could be explored further for diagnostic application in allergic aspergillosis asthmatics including ABPA. Results Peptide mass fingerprint using matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) and/or de novo sequencing by MS/MS analysis of the protein spots from 2-D gels led to the identification of a total of 16 allergens of Afu. Eleven of them are being reported as allergens for the first time and five had been reported earlier. Putative isoforms of the proteins Asp f 13 and chitosanase have been observed for the first time. When studied for reactivity of these proteins among patients with ABPA using their individual sera, these patients exhibited sensitization although the pattern was varying. Taken together, these proteins could thus be considered as potential allergens even among patients with ABPA. Three of these proteins viz. the hypothetical protein (# spot no. 5), extracellular arabinase (# spot no. 6) and chitosanase (# spot no. 11) could be major allergens with specific IgE immunoreactivity with six out of eight patients' sera. Conclusions The immunoproteomic approach applied to the analysis of culture filtrate proteins resulted in the identification of several candidate allergens, many of them novel, contributing to the catalogue of Afu allergenic proteins, which would facilitate improved serodiagnosis for allergic aspergillosis. In addition, the immunoreactivity of these proteins observed among the patients with ABPA may be potentially useful for its serodiagnosis and opens up further opportunities for the development of personalized immunotherapeutics for patients with ABPA.

High throughput molecular profiling and integrated data analysis with tumor tissues require overcoming challenges like tumor heterogeneity and tissue paucity. This study is an attempt to understand and optimize various steps during tissue processing and in establishing pipelines essential for integrated analysis. Towards this effort, we subjected laryngo-pharyngeal primary tumors and the corresponding adjacent normal tissues (n=2) to two RNA and protein isolation methods, one wherein RNA and protein were isolated from the same tissue sequentially (Method 1) and second, wherein the extraction was carried out using two independent methods (Method 2). RNA and protein from both methods were subjected to RNA-seq and iTRAQ based LC-MS/MS analysis. Transcript and peptide identification and quantification was followed by both individual -ome and integrated data analysis. As a result of this analysis, we identified a higher number of total, as well as differentially expressed (DE) transcripts (1329 vs 1134) and proteins (799 vs 408) with fold change ≥ 2.0, in Method 1. Among these, 173 and 86 entities were identified by both transcriptome and proteome analysis in Method 1 and 2, respectively, with higher concordance in the regulation trends observed in the former. The significant cancer related pathways enriched with the individual DE transcript or protein data were similar in both the methods. However, the entities mapping to them were different, allowing enhanced view of the pathways identified after integration of the data and subsequent mapping. The concordant DE transcripts and proteins also revealed key molecules of the pathways with important roles in cancer development. This study thus demonstrates that sequential extraction of the RNA and proteins from the same tissue allows for better profiling of differentially expressed entities and a more accurate integrated data analysis.

In line with the aims of the Chromosome-based Human Proteome Project and the Biology/Disease-based Human Proteome Project, we have been studying differentially expressed transcripts and proteins in gliomas—the most prevalent primary brain tumors. Here, we present a perspective on important insights from this analysis in terms of their co-expression, co-regulation/de-regulation, and co-localization on chromosome 12 (Chr. 12). We observe the following: (1) Over-expression of genes mapping onto amplicon regions of chromosomes may be considered as a biological validation of mass spectrometry data. (2) Their co-localization further suggests common determinants of co-expression and co-regulation of these clusters. (3) Co-localization of "missing" protein genes of Chr. 12 in close proximity to functionally related genes may help in predicting their functions. (4) Further, integrating differentially expressed gene-protein sets and their ontologies with medical terms associated with clinical phenotypes in a chromosome-centric manner reveals a network of genes, diseases, and pathways—a diseasome network. Thus, chromosomal mapping of disease data sets can help uncover important regulatory and functional links that may offer new insights for biomarker development.

The Draft Maps of Human Proteome published in two independent articles provide a catalogue of proteins encoded in the human genome including missing proteins, based on large scale mass spectrometric analysis. Six months later, a Tissue-based Human Proteome Map was published which includes a study of expression and distribution of human proteins across tissues and cells using specific antibodies. Independently, in an ongoing global effort — the Chromosome centric, and Biology and Disease centric Human Proteome Project (C-HPP and B/D-HPP) initiated by the Human Proteome Organization aims to study in-depth human proteins and their variants in terms of biology and disease in a chromosome centric manner. Under this initiative, a consortium formed among five Asian research teams including India aims to study Chromosome 12 encoded proteins and their disease context. Together, the group has recently published the first series of 3 papers giving the overall vision and the initial contributions. While one of the draft maps of the human proteome is largely contributed by an Indian team, Indian researchers have significant role in the other two initiatives as well. These efforts will be pursued further as more teams join and more disease and biology components get incorporated. Biological significance This article focuses on the complexity and challenges of deciphering human proteome and contribution of Indian researchers in the human proteome projects, including the on-going C-HPP. This article is part of a Special Issue entitled: Proteomics in India.

Peripheral monocytes, precursors of osteoclasts, have emerged as important candidates for identifying proteins relevant to osteoporosis, a condition characterized by low Bone Mineral Density (BMD) and increased susceptibility for fractures. We employed 4-plex iTRAQ (isobaric tags for relative and absolute quantification) coupled with LC-MS/MS (liquid chromatography coupled with tandem mass spectrometry) to identify differentially expressed monocyte proteins from premenopausal and postmenopausal women with low versus high BMD. Of 1801 proteins identified, 45 were differentially abundant in low versus high BMD, with heat shock protein 27 (HSP27) distinctly upregulated in low BMD condition in both premenopausal and postmenopausal categories. Validation in individual samples (n=80) using intracellular ELISA confirmed that total HSP27 (tHSP27) as well as phosphorylated HSP27 (pHSP27) was elevated in low BMD condition in both categories (P<0.05). Further, using transwell assays, pHSP27, when placed in the upper chamber, could increase monocyte migration (P<0.0001) and this was additive in combination with RANKL (receptor activator ofNFkBligand) placed in the lower chamber (P=0.05). Effect of pHSP27 in monocyte migration towards bone milieu can result in increased osteoclast formation and thus contribute to pathogenesis of osteoporosis. Overall, this study reveals for the first time a novel link between monocyte HSP27 and BMD.

The genus Pseudomonas is a group of gram-negative, motile, rod-shaped bacteria known for their metabolic versatility. One of the species is Pseudomonas fluorescens, which has an efficient system for detoxification of industrial waste. Other aspects include, catabolic versatility, excellent root colonizing abilities and capacity to produce a wide range of antifungal metabolites. They are also known for their resistance and survival in the presence of several organic and inorganic pollutants. P. fluorescens has also been isolated from metal polluted water and soils but the elucidation of proteins responsible for its survival is still not clear. The aim of the study was to elucidate the differential protein expression of this bacterium when exposed to heavy metal stress, using two-dimensional electrophoresis. The proteins spo VG and enolase showed upregulation during the bacterial exposure to lead and copper. Hypothetical protein showed downregulation when bacterium was exposed to cobalt. Some proteins like xylosyltransferase, ORF 18 phage phi KZ, OMP H1 and translational elongation factor EF-Tu appeared only during their exposure to cobalt. These were absent in the control condition. Analysis of the differentially expressed proteins as well as the newly synthesized proteins along with the results obtained growth and enzyme activity indicate the involvement of all these factors in the survival of this organism in the presence of heavy metals.

Accurate annotation of protein-coding genes is one of the primary tasks upon the completion of whole genome sequencing of any organism. In this study, we used an integrated transcriptomic and proteomic strategy to validate and improve the existing zebrafish genome annotation. We undertook high-resolution mass-spectrometry-based proteomic profiling of 10 adult organs, whole adult fish body, and two developmental stages of zebrafish (SAT line), in addition to transcriptomic profiling of six organs. More than 7,000 proteins were identified from proteomic analyses, and ∼ 69,000 high-confidence transcripts were assembled from the RNA sequencing data. Approximately 15% of the transcripts mapped to intergenic regions, the majority of which are likely long non-coding RNAs. These high-quality transcriptomic and proteomic data were used to manually reannotate the zebrafish genome. We report the identification of 157 novel protein-coding genes. In addition, our data led to modification of existing gene structures including novel exons, changes in exon coordinates, changes in frame of translation, translation in annotated UTRs, and joining of genes. Finally, we discovered four instances of genome assembly errors that were supported by both proteomic and transcriptomic data. Our study shows how an integrative analysis of the transcriptome and the proteome can extend our understanding of even well-annotated genomes.

Gliomas are the most common of the primary intracranial tumors with astrocytomas constituting about 40%. Using clinically and histologically assessed astrocytomas, we have studied their protein profiles using a two-dimensional gel electrophoresis-mass spectrometry approach and identified differentially expressed proteins which may be useful molecular indicators to understand these tumors. Examination of the protein profiles of 27 astrocytoma samples of different grades revealed 72 distinct, differentially expressed proteins belonging to various functional groups such as cytoskeleton and intermediate filament proteins, heat shock proteins (HSPs), enzymes and regulatory proteins. Based on the consistency of their differential expression, 29 distinct proteins could be short-listed and may have a role in the pathology of astrocytomas. Some were found to be differentially expressed in both Grade III and IV astrocytomas while others were associated with a particular grade. A notable observation was underexpression of Prohibitin, a potential tumor suppressor protein, Rho-GDP dissociation inhibitor, Rho-GDI, a regulator of Rho GTPases and HSPs as well as destabilization of glial fibrillary acidic protein, GFAP, major protein of the glial filaments, in Grade III malignant tumors. We attempt to explain glioma malignancy and progression in terms of their combined role.