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Muhammad Saddiq Zahari

Bio: Muhammad Saddiq Zahari is an academic researcher from Johns Hopkins University. The author has contributed to research in topics: Breast cancer & Receptor tyrosine kinase. The author has an hindex of 10, co-authored 13 publications receiving 1912 citations. Previous affiliations of Muhammad Saddiq Zahari include University of California, San Francisco & Johns Hopkins University School of Medicine.

Papers
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Journal ArticleDOI
29 May 2014-Nature
TL;DR: A draft map of the human proteome is presented using high-resolution Fourier-transform mass spectrometry to discover a number of novel protein-coding regions, which includes translated pseudogenes, non-c coding RNAs and upstream open reading frames.
Abstract: 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.

1,965 citations

Journal ArticleDOI
TL;DR: It is demonstrated that phosphorylation of cortactin by AKT1 is important for mutant PI3K enhanced cell migration and invasion through mutagenesis studies, and a quantitative and global approach is described for identifying mutation-specific signaling events and for discovering novel signaling molecules as readouts of pathway activation or potential therapeutic targets.
Abstract: The PIK3CA gene is frequently mutated in human cancers. Here we carry out a SILAC-based quantitative phosphoproteomic analysis using isogenic knockin cell lines containing 'driver' oncogenic mutations of PIK3CA to dissect the signalling mechanisms responsible for oncogenic phenotypes induced by mutant PIK3CA. From 8,075 unique phosphopeptides identified, we observe that aberrant activation of PI3K pathway leads to increased phosphorylation of a surprisingly wide variety of kinases and downstream signalling networks. Here, by integrating phosphoproteomic data with human protein microarray-based AKT1 kinase assays, we discover and validate six novel AKT1 substrates, including cortactin. Through mutagenesis studies, we demonstrate that phosphorylation of cortactin by AKT1 is important for mutant PI3K-enhanced cell migration and invasion. Our study describes a quantitative and global approach for identifying mutation-specific signalling events and for discovering novel signalling molecules as readouts of pathway activation or potential therapeutic targets.

65 citations

Journal ArticleDOI
TL;DR: The phosphotyrosine proteome analysis provided new insights into the heterogeneity in the activation status of tyrosine kinase pathways in TNBCs and presented an effective means of identifying important novel biomarkers and targets for therapy such as AXL in T NBC.
Abstract: Breast cancer is the most prevalent cancer in women worldwide. About 15-20% of all breast cancers are triple negative breast cancer (TNBC) and are often highly aggressive when compared to other subtypes of breast cancers. To better characterize the biology that underlies the TNBC phenotype, we profiled the phosphotyrosine proteome of a panel of twenty-six TNBC cell lines using quantitative high resolution Fourier transform mass spectrometry. A heterogeneous pattern of tyrosine kinase activation was observed based on 1,789 tyrosine-phosphorylated peptides identified from 969 proteins. One of the tyrosine kinases, AXL, was found to be activated in a majority of aggressive TNBC cell lines and was accompanied by a higher level of AXL expression. High levels of AXL expression are correlated with a significant decrease in patient survival. Treatment of cells bearing activated AXL with a humanized AXL antibody inhibited cell proliferation and migration in vitro, and tumor growth in mice. Overall, our global phosphoproteomic analysis provided new insights into the heterogeneity in the activation status of tyrosine kinase pathways in TNBCs. Our approach presents an effective means of identifying important novel biomarkers and targets for therapy such as AXL in TNBC.

41 citations

Journal ArticleDOI
TL;DR: It is demonstrated that knockdown of TNK2 expression can substantially suppress the invasiveness and proliferation advantage of TNBC cells in vitro and tumor formation in xenograft mouse models, and this study suggests thatTNK2 is a novel potential therapeutic target for the treatment of T NBC.
Abstract: // Xinyan Wu 1, 2, * , Muhammad Saddiq Zahari 1, 2, * , Santosh Renuse 1, 2, 5 , Dhanashree S. Kelkar 1, 2 , Mustafa A. Barbhuiya 2 , Pamela L. Rojas 1, 2 , Vered Stearns 3 , Edward Gabrielson 3, 4 , Pavani Malla 6 , Saraswati Sukumar 3 , Nupam P. Mahajan 6, 7 , Akhilesh Pandey 1, 2, 3, 4 1 Department of Biological Chemistry, Johns Hopkins University School of Medicine Baltimore, MD 21205, U.S.A 2 McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine Baltimore, MD 21205, U.S.A 3 Department of Oncology, Johns Hopkins University School of Medicine Baltimore, MD 21205, U.S.A 4 Department of Pathology, Johns Hopkins University School of Medicine Baltimore, MD 21205, U.S.A 5 Institute of Bioinformatics, International Technology Park, Bangalore, 560066, India 6 Department of Drug Discovery, Moffitt Cancer Center, Tampa, FL 33612, U.S.A 7 Department of Oncologic Sciences, University of South Florida, Tampa, FL 33612, U.S.A * These authors have contributed equally to this work Correspondence to: Xinyan Wu, email: xinyan@jhmi.edu Nupam P. Mahajan, email: Nupam.mahajan@moffitt.org Akhilesh Pandey, email: pandey@jhmi.edu Keywords: TNK2, triple negative breast cancer, tyrosine kinase, phosphorylation Received: March 11, 2016 Accepted: October 10, 2016 Published: November 25, 2016 ABSTRACT Breast cancer is the most prevalent cancer in women worldwide. About 15-20% of all breast cancers do not express estrogen receptor, progesterone receptor or HER2 receptor and hence are collectively classified as triple negative breast cancer (TNBC). These tumors are often relatively aggressive when compared to other types of breast cancer, and this issue is compounded by the lack of effective targeted therapy. In our previous phosphoproteomic profiling effort, we identified the non-receptor tyrosine kinase TNK2 as activated in a majority of aggressive TNBC cell lines. In the current study, we show that high expression of TNK2 in breast cancer cell lines correlates with high proliferation, invasion and colony forming ability. We demonstrate that knockdown of TNK2 expression can substantially suppress the invasiveness and proliferation advantage of TNBC cells in vitro and tumor formation in xenograft mouse models. Moreover, inhibition of TNK2 with small molecule inhibitor ( R )-9bMS significantly compromised TNBC proliferation. Finally, we find that high levels of TNK2 expression in high-grade basal-like breast cancers correlates significantly with poorer patient outcome. Taken together, our study suggests that TNK2 is a novel potential therapeutic target for the treatment of TNBC.

36 citations

Journal ArticleDOI
TL;DR: Living analysis revealed that high expression of FAK2 is significantly associated with shorter metastasis-free survival in estrogen receptor-positive breast cancer patients treated with tamoxifen, and studies suggest that FAK 2 is a potential therapeutic target for the management of hormone-refractory breast cancers.

21 citations


Cited by
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Journal ArticleDOI
23 Jan 2015-Science
TL;DR: In this paper, a map of the human tissue proteome based on an integrated omics approach that involves quantitative transcriptomics at the tissue and organ level, combined with tissue microarray-based immunohistochemistry, to achieve spatial localization of proteins down to the single-cell level.
Abstract: Resolving the molecular details of proteome variation in the different tissues and organs of the human body will greatly increase our knowledge of human biology and disease. Here, we present a map of the human tissue proteome based on an integrated omics approach that involves quantitative transcriptomics at the tissue and organ level, combined with tissue microarray-based immunohistochemistry, to achieve spatial localization of proteins down to the single-cell level. Our tissue-based analysis detected more than 90% of the putative protein-coding genes. We used this approach to explore the human secretome, the membrane proteome, the druggable proteome, the cancer proteome, and the metabolic functions in 32 different tissues and organs. All the data are integrated in an interactive Web-based database that allows exploration of individual proteins, as well as navigation of global expression patterns, in all major tissues and organs in the human body.

9,745 citations

Journal ArticleDOI
TL;DR: A significant update to one of the tools in this domain called Enrichr, a comprehensive resource for curated gene sets and a search engine that accumulates biological knowledge for further biological discoveries is presented.
Abstract: Enrichment analysis is a popular method for analyzing gene sets generated by genome-wide experiments. Here we present a significant update to one of the tools in this domain called Enrichr. Enrichr currently contains a large collection of diverse gene set libraries available for analysis and download. In total, Enrichr currently contains 180 184 annotated gene sets from 102 gene set libraries. New features have been added to Enrichr including the ability to submit fuzzy sets, upload BED files, improved application programming interface and visualization of the results as clustergrams. Overall, Enrichr is a comprehensive resource for curated gene sets and a search engine that accumulates biological knowledge for further biological discoveries. Enrichr is freely available at: http://amp.pharm.mssm.edu/Enrichr.

6,201 citations

Journal ArticleDOI
TL;DR: The developments in PRIDE resources and related tools are summarized and a brief update on the resources under development 'PRIDE Cluster' and 'PRide Proteomes', which provide a complementary view and quality-scored information of the peptide and protein identification data available inPRIDE Archive are given.
Abstract: The PRoteomics IDEntifications (PRIDE) database is one of the world-leading data repositories of mass spectrometry (MS)-based proteomics data Since the beginning of 2014, PRIDE Archive (http://wwwebiacuk/pride/archive/) is the new PRIDE archival system, replacing the original PRIDE database Here we summarize the developments in PRIDE resources and related tools since the previous update manuscript in the Database Issue in 2013 PRIDE Archive constitutes a complete redevelopment of the original PRIDE, comprising a new storage backend, data submission system and web interface, among other components PRIDE Archive supports the most-widely used PSI (Proteomics Standards Initiative) data standard formats (mzML and mzIdentML) and implements the data requirements and guidelines of the ProteomeXchange Consortium The wide adoption of ProteomeXchange within the community has triggered an unprecedented increase in the number of submitted data sets (around 150 data sets per month) We outline some statistics on the current PRIDE Archive data contents We also report on the status of the PRIDE related stand-alone tools: PRIDE Inspector, PRIDE Converter 2 and the ProteomeXchange submission tool Finally, we will give a brief update on the resources under development 'PRIDE Cluster' and 'PRIDE Proteomes', which provide a complementary view and quality-scored information of the peptide and protein identification data available in PRIDE Archive

3,375 citations

Journal ArticleDOI
TL;DR: The lncRNA landscape characterized here may shed light on normal biology and cancer pathogenesis and may be valuable for future biomarker development.
Abstract: Long noncoding RNAs (lncRNAs) are emerging as important regulators of tissue physiology and disease processes including cancer. To delineate genome-wide lncRNA expression, we curated 7,256 RNA sequencing (RNA-seq) libraries from tumors, normal tissues and cell lines comprising over 43 Tb of sequence from 25 independent studies. We applied ab initio assembly methodology to this data set, yielding a consensus human transcriptome of 91,013 expressed genes. Over 68% (58,648) of genes were classified as lncRNAs, of which 79% were previously unannotated. About 1% (597) of the lncRNAs harbored ultraconserved elements, and 7% (3,900) overlapped disease-associated SNPs. To prioritize lineage-specific, disease-associated lncRNA expression, we employed non-parametric differential expression testing and nominated 7,942 lineage- or cancer-associated lncRNA genes. The lncRNA landscape characterized here may shed light on normal biology and cancer pathogenesis and may be valuable for future biomarker development.

2,209 citations

Journal ArticleDOI
TL;DR: The evidence for and against the ceRNA hypothesis are critically evaluated to assess the impact of endogenous miRNA-sponge interactions and to propose an alternative function for messenger RNAs.
Abstract: The competitive endogenous RNA (ceRNA) hypothesis proposes that transcripts with shared microRNA (miRNA) binding sites compete for post-transcriptional control. This hypothesis has gained substantial attention as a unifying function for long non-coding RNAs, pseudogene transcripts and circular RNAs, as well as an alternative function for messenger RNAs. Empirical evidence supporting the hypothesis is accumulating but not without attracting scepticism. Recent studies that model transcriptome-wide binding-site abundance suggest that physiological changes in expression of most individual transcripts will not compromise miRNA activity. In this Review, we critically evaluate the evidence for and against the ceRNA hypothesis to assess the impact of endogenous miRNA-sponge interactions.

1,463 citations