@article {69773, title = {Live imaging of the extracellular matrix with a glycan-binding fluorophore.}, journal = {Nat Methods}, year = {2025}, month = {2025 Feb 06}, abstract = {

All multicellular systems produce and dynamically regulate extracellular matrices (ECMs) that play essential roles in both biochemical and mechanical signaling. Though the spatial arrangement of these extracellular assemblies is critical to their biological functions, visualization of ECM structure is challenging, in part because the biomolecules that compose the ECM are difficult to fluorescently label individually and collectively. Here, we present a cell-impermeable small-molecule fluorophore, termed Rhobo6, that turns on and red shifts upon reversible binding to glycans. Given that most ECM components are densely glycosylated, the dye enables wash-free visualization of ECM, in systems ranging from in vitro substrates to in vivo mouse mammary tumors. Relative to existing techniques, Rhobo6 provides a broad substrate profile, superior tissue penetration, non-perturbative labeling, and negligible photobleaching. This work establishes a straightforward method for imaging the distribution of ECM in live tissues and organisms, lowering barriers for investigation of extracellular biology.

}, issn = {1548-7105}, doi = {10.1038/s41592-024-02590-2}, url = {https://doi.org/10.1038/s41592-024-02590-2}, author = {Fiore, Antonio and Yu, Guoqiang and Northey, Jason J and Patel, Ronak and Ravenscroft, Thomas A. and Ikegami, Richard and Kolkman, W and Pratik Kumar and Dilan, Tanya L and Ruetten, Virginia M.S. and Ahrens, Misha B and Shroff, Hari and Wang, Shaohe and Weaver, Valarie M and Pedram, Kayvon} } @article {69397, title = {Expansion of in vitro Toxoplasma gondii cysts using enzymatically enhanced ultrastructure expansion microscopy}, journal = {mSphere}, volume = {e0032224}, year = {2024}, month = {2024 Aug 27}, abstract = {

Expansion microscopy (ExM) is an innovative approach to achieve super-resolution images without using super-resolution microscopes, based on the physical expansion of the sample. The advent of ExM has unlocked the detail of super-resolution images for a broader scientific circle, lowering the cost and entry skill requirements for the field. One of its branches, ultrastructure expansion microscopy (U-ExM), has become popular among research groups studying apicomplexan parasites, including the acute stage of Toxoplasma gondii infection. Here, we show that the chronic cyst-forming stage of Toxoplasma, however, resists U-ExM expansion, impeding precise protein localization. We then solve the in vitro cyst{\textquoteright}s resistance to denaturation required for successful U-ExM. As the cyst{\textquoteright}s main structural protein CST1 contains a mucin domain, we added an enzymatic digestion step using the pan-mucinase StcE prior to the expansion protocol. This allowed full expansion of the cysts in fibroblasts and primary neuronal cell culture without disrupting immunofluorescence analysis of parasite proteins. Using StcE-enhanced U-ExM, we clarified the localization of the GRA2 protein, which is important for establishing a normal cyst, observing GRA2 granules spanning across the CST1 cyst wall. The StcE-U-ExM protocol allows accurate pinpointing of proteins in the bradyzoite cyst, which will greatly facilitate investigation of the underlying biology of cyst formation and its vulnerabilities.

}, doi = {10.1128/msphere.00322-24}, url = {https://www.doi.org/10.1128/msphere.00322-24}, author = {Bondarenko, Kseniia and Limoge, Floriane and Pedram, Kayvon and Gissot, Mathieu and Young, Joanna C.} } @article {69440, title = {Imaging the extracellular matrix in live tissues and organisms with a glycan-binding fluorophore}, journal = {bioRxiv}, year = {2024}, month = {2024 May 10}, abstract = {

All multicellular systems produce and dynamically regulate extracellular matrices (ECM) that play important roles in both biochemical and mechanical signaling. Though the spatial arrangement of these extracellular assemblies is critical to their biological functions, visualization of ECM structure is challenging, in part because the biomolecules that compose the ECM are difficult to fluorescently label individually and collectively. Here, we present a cell-impermeable small molecule fluorophore, termed Rhobo6, that turns on and red shifts upon reversible binding to glycans. Given that most ECM components are densely glycosylated, the dye enables wash-free visualization of ECM, in systems ranging from in vitro substrates to in vivo mouse mammary tumors. Relative to existing techniques, Rhobo6 provides a broad substrate profile, superior tissue penetration, nonperturbative labeling, and negligible photobleaching. This work establishes a straightforward method for imaging the distribution of ECM in live tissues and organisms, lowering barriers for investigation of extracellular biology.

}, doi = {10.1101/2024.05.09.593460}, url = {https://www.biorxiv.org/content/early/2024/05/10/2024.05.09.593460}, author = {Fiore, Antonio and Yu, Guoqiang and Northey, Jason J. and Patel, Ronak and Ravenscroft, Thomas A. and Ikegami, Richard and Kolkman, Wiert and Kumar, Pratik and Grimm, Jonathan B. and Dilan, Tanya L. and Ruetten, Virginia M.S. and Ahrens, Misha B. and Shroff, Hari and Lavis, Luke D. and Wang, Shaohe and Weaver, Valerie M. and Pedram, Kayvon} } @article {68530, title = {Small molecule inhibitors of mammalian glycosylation.}, journal = {Matrix Biology Plus}, volume = {16}, year = {2022}, month = {2022 Mar 16}, pages = {100108}, abstract = {

Glycans are one of the fundamental biopolymers encountered in living systems. Compared to polynucleotide and polypeptide biosynthesis, polysaccharide biosynthesis is a uniquely combinatorial process to which interdependent enzymes with seemingly broad specificities contribute. The resulting intracellular cell surface, and secreted glycans play key roles in health and disease, from embryogenesis to cancer progression. The study and modulation of glycans in cell and organismal biology is aided by small molecule inhibitors of the enzymes involved in glycan biosynthesis. In this review, we survey the arsenal of currently available inhibitors, focusing on agents which have been independently validated in diverse systems. We highlight the utility of these inhibitors and drawbacks to their use, emphasizing the need for innovation for basic research as well as for therapeutic applications.

}, issn = {2590-0285}, doi = {10.1016/j.mbplus.2022.100108}, author = {Almahayni, Karim and Spiekermann, Malte and Fiore, Antonio and Yu, Guoqiang and Pedram, Kayvon and M{\"o}ckl, Leonhard} } @article {66018, title = {An Acquired and Endogenous Glycocalyx Forms a Bidirectional {\textquotedblleft}Don{\textquoteright}t Eat{\textquotedblright} and {\textquotedblleft}Don{\textquoteright}t Eat Me{\textquotedblright} Barrier to Phagocytosis}, journal = {Current Biology}, volume = {31}, year = {2021}, month = {Jan-01-2021}, pages = {77 - 89.e5}, abstract = {

Macrophages continuously survey their environment in search of pathogens or apoptotic corpses or debris. Targets intended for clearance expose ligands that initiate their phagocytosis ("eat me" signals), while others avoid phagocytosis by displaying inhibitory ligands ("don{\textquoteright}t eat me" signals). We report that such ligands can be obscured by the glycosaminoglycans and glycoproteins that coat pathogenic as well as malignant phagocytic targets. In addition, a reciprocal barrier of self-synthesized or acquired glycocalyx components on the macrophage surface shrouds phagocytic receptors, curtailing their ability to engage particles. The coating layers of macrophages and their targets hinder phagocytosis by both steric and electrostatic means. Their removal by enzymatic means is shown to markedly enhance phagocytic efficiency. In particular, we show that the removal of mucins, which are overexpressed in cancer cells, facilitates their clearance. These results shed light on the physical barriers that modulate phagocytosis, which have been heretofore underappreciated.

}, issn = {09609822}, doi = {10.1016/j.cub.2020.09.082}, url = {https://www.sciencedirect.com/science/article/pii/S0960982220314950?via\%3Dihub}, author = {Imbert, Paul R.C. and Saric, Amra and Pedram, Kayvon and Bertozzi, Carolyn R. and Grinstein, Sergio and Freeman, Spencer A.} } @article {66015, title = {Bump-and-Hole Engineering Identifies Specific Substrates of Glycosyltransferases in Living Cells}, journal = {Molecular Cell}, volume = {78}, year = {2020}, month = {Jan-06-2020}, pages = {824 - 834.e15}, abstract = {

Studying posttranslational modifications classically relies on experimental strategies that oversimplify the complex biosynthetic machineries of living cells. Protein glycosylation contributes to essential biological processes, but correlating glycan structure, underlying protein, and disease-relevant biosynthetic regulation is currently elusive. Here, we engineer living cells to tag glycans with editable chemical functionalities while providing information on biosynthesis, physiological context, and glycan fine structure. We introduce a non-natural substrate biosynthetic pathway and use engineered glycosyltransferases to incorporate chemically tagged sugars into the cell surface glycome of the living cell. We apply the strategy to a particularly redundant yet disease-relevant human glycosyltransferase family, the polypeptide\ N-acetylgalactosaminyl transferases. This approach bestows a gain-of-chemical-functionality modification on cells, where the products of individual glycosyltransferases can be selectively characterized or manipulated to understand glycan contribution to major physiological processes.

}, issn = {10972765}, doi = {10.1016/j.molcel.2020.03.030}, url = {https://www.sciencedirect.com/science/article/pii/S1097276520301982?via\%3Dihub}, author = {Schumann, Benjamin and Malaker, Stacy Alyse and Wisnovsky, Simon Peter and Debets, Marjoke Froukje and Agbay, Anthony John and Fernandez, Daniel and Wagner, Lauren Jan Sarbo and Lin, Liang and Li, Zhen and Choi, Junwon and Fox, Douglas Michael and Peh, Jessie and Gray, Melissa Anne and Pedram, Kayvon and Kohler, Jennifer Jean and Mrksich, Milan and Bertozzi, Carolyn Ruth} } @article {66017, title = {An enzymatic toolkit for selective proteolysis, detection, and visualization of mucin-domain glycoproteins}, journal = {Proceedings of the National Academy of Sciences}, volume = {117}, year = {2020}, month = {Jan-09-2020}, pages = {21299 - 21307}, abstract = {

Densely O-glycosylated mucin domains are found in a broad range of cell surface and secreted proteins, where they play key physiological roles. In addition, alterations in mucin expression and glycosylation are common in a variety of human diseases, such as cancer, cystic fibrosis, and inflammatory bowel diseases. These correlations have been challenging to uncover and establish because tools that specifically probe mucin domains are lacking. Here, we present a panel of bacterial proteases that cleave mucin domains via distinct peptide- and glycan-based motifs, generating a diverse enzymatic toolkit for mucin-selective proteolysis. By mutating catalytic residues of two such enzymes, we engineered mucin-selective binding agents with retained glycoform preferences. StcEE447D\ is a pan-mucin stain derived from enterohemorrhagic\ Escherichia coli\ that is tolerant to a wide range of glycoforms. BT4244E575A\ derived from\ Bacteroides thetaiotaomicron\ is selective for truncated, asialylated core 1 structures commonly associated with malignant and premalignant tissues. We demonstrated that these catalytically inactive point mutants enable robust detection and visualization of mucin-domain glycoproteins by flow cytometry, Western blot, and immunohistochemistry. Application of our enzymatic toolkit to ascites fluid and tissue slices from patients with ovarian cancer facilitated characterization of patients based on differences in mucin cleavage and expression patterns.

}, issn = {0027-8424}, doi = {10.1073/pnas.2012196117}, url = {http://www.pnas.org/lookup/doi/10.1073/pnas.2012196117https://syndication.highwire.org/content/doi/10.1073/pnas.2012196117http://www.pnas.org/syndication/doi/10.1073/pnas.2012196117}, author = {Shon, D. Judy and Malaker, Stacy A. and Pedram, Kayvon and Yang, Emily and Krishnan, Venkatesh and Dorigo, Oliver and Bertozzi, Carolyn R.} } @article {66016, title = {Lysosome-targeting chimaeras for degradation of extracellular proteins}, journal = {Nature}, volume = {584}, year = {2020}, month = {Jan-08-2021}, pages = {291 - 297}, abstract = {

The majority of therapies that target individual proteins rely on specific activity-modulating interactions with the target protein{\textemdash}for example, enzyme inhibition or ligand blocking. However, several major classes of therapeutically relevant proteins have unknown or inaccessible activity profiles and so cannot be targeted by such strategies. Protein-degradation platforms such as proteolysis-targeting chimaeras (PROTACs)1,2\ and others (for example, dTAGs3, Trim-Away4, chaperone-mediated autophagy targeting5\ and SNIPERs6) have been developed for proteins that are typically difficult to target; however, these methods involve the manipulation of intracellular protein degradation machinery and are therefore fundamentally limited to proteins that contain cytosolic domains to which ligands can bind and recruit the requisite cellular components. Extracellular and membrane-associated proteins{\textemdash}the products of 40\% of all protein-encoding genes7{\textemdash}are key agents in cancer, ageing-related diseases and autoimmune disorders8, and so a general strategy to selectively degrade these proteins has the potential to improve human health. Here we establish the targeted degradation of extracellular and membrane-associated proteins using conjugates that bind both a cell-surface lysosome-shuttling receptor and the extracellular domain of a target protein. These initial lysosome-targeting chimaeras, which we term LYTACs, consist of a small molecule or antibody fused to chemically synthesized glycopeptide ligands that are agonists of the cation-independent mannose-6-phosphate receptor (CI-M6PR). We use LYTACs to develop a CRISPR interference screen that reveals the biochemical pathway for CI-M6PR-mediated cargo internalization in cell lines, and uncover the exocyst complex as a previously unidentified{\textemdash}but essential{\textemdash}component of this pathway. We demonstrate the scope of this platform through the degradation of therapeutically relevant proteins, including apolipoprotein\ E4, epidermal growth factor receptor, CD71 and programmed death-ligand 1. Our results establish a modular strategy for directing secreted and membrane proteins for lysosomal degradation, with broad implications for biochemical research and for therapeutics.

}, issn = {0028-0836}, doi = {10.1038/s41586-020-2545-9}, url = {http://www.nature.com/articles/s41586-020-2545-9http://www.nature.com/articles/s41586-020-2545-9.pdfhttp://www.nature.com/articles/s41586-020-2545-9.pdfhttp://www.nature.com/articles/s41586-020-2545-9}, author = {Banik, Steven M. and Pedram, Kayvon and Wisnovsky, Simon and Ahn, Green and Riley, Nicholas M. and Bertozzi, Carolyn R.} } @article {66012, title = {The mucin-selective protease StcE enables molecular and functional analysis of human cancer-associated mucins}, journal = {Proceedings of the National Academy of Sciences}, volume = {116}, year = {2019}, month = {Sep-04-2019}, pages = {7278 - 7287}, abstract = {

Mucin domains are densely\ O-glycosylated modular protein domains that are found in a wide variety of cell surface and secreted proteins. Mucin-domain glycoproteins are known to be key players in a host of human diseases, especially cancer, wherein mucin expression and glycosylation patterns are altered. Mucin biology has been difficult to study at the molecular level, in part, because methods to manipulate and structurally characterize mucin domains are lacking. Here, we demonstrate that secreted protease of C1 esterase inhibitor (StcE), a bacterial protease from\ Escherichia coli, cleaves mucin domains by recognizing a discrete peptide- and glycan-based motif. We exploited StcE{\textquoteright}s unique properties to improve sequence coverage, glycosite mapping, and glycoform analysis of recombinant human mucins by mass spectrometry. We also found that StcE digests cancer-associated mucins from cultured cells and from ascites fluid derived from patients with ovarian cancer. Finally, using StcE, we discovered that sialic acid-binding Ig-type lectin-7 (Siglec-7), a glycoimmune checkpoint receptor, selectively binds sialomucins as biological ligands, whereas the related receptor Siglec-9 does not. Mucin-selective proteolysis, as exemplified by StcE, is therefore a powerful tool for the study of mucin domain structure and function.

}, issn = {0027-8424}, doi = {10.1073/pnas.1813020116}, url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1813020116https://syndication.highwire.org/content/doi/10.1073/pnas.1813020116http://www.pnas.org/syndication/doi/10.1073/pnas.1813020116}, author = {Malaker, Stacy A. and Pedram, Kayvon and Ferracane, Michael J. and Bensing, Barbara A. and Krishnan, Venkatesh and Pett, Christian and Yu, Jin and Woods, Elliot C. and Kramer, Jessica R. and Westerlind, Ulrika and Dorigo, Oliver and Bertozzi, Carolyn R.} } @article {66014, title = {Physical Principles of Membrane Shape Regulation by the Glycocalyx}, journal = {Cell}, volume = {177}, year = {2019}, month = {Jan-06-2019}, pages = {1757 - 1770.e21}, abstract = {

Cells bend their plasma membranes into highly curved forms to interact with the local environment, but how shape generation is regulated is not fully resolved. Here, we report a synergy between shape-generating processes in the cell interior and the external organization and composition of the cell-surface\ glycocalyx.\ Mucinbiopolymers\ and long-chain\ polysaccharides\ within the glycocalyx can generate entropic forces that favor or disfavor the projection of spherical and finger-like extensions from the cell surface. A polymer brush model of the glycocalyx successfully predicts the effects of polymer size and cell-surface density on membrane morphologies. Specific glycocalyx compositions can also induce plasma membrane instabilities to generate more exotic undulating and pearled\ membrane structures\ and drive secretion of extracellular vesicles. Together, our results suggest a fundamental role for the glycocalyx in regulating curved membrane features that serve in communication between cells and with the\ extracellular matrix.

}, issn = {00928674}, doi = {10.1016/j.cell.2019.04.017}, url = {https://www.sciencedirect.com/science/article/pii/S0092867419304039?via\%3Dihub}, author = {Shurer, Carolyn R. and Kuo, Joe Chin-Hun and Roberts, LaDeidra Mon{\'e}t and Gandhi, Jay G. and Colville, Marshall J. and Enoki, Thais A. and Pan, Hao and Su, Jin and Noble, Jade M. and Hollander, Michael J. and O{\textquoteright}Donnell, John P. and Yin, Rose and Pedram, Kayvon and M{\"o}ckl, Leonhard and Kourkoutis, Lena F. and Moerner, W.E. and Bertozzi, Carolyn R. and Feigenson, Gerald W. and Reesink, Heidi L. and Paszek, Matthew J.} } @article {66013, title = {Quantitative Super-Resolution Microscopy of the Mammalian Glycocalyx}, journal = {Developmental Cell}, volume = {50}, year = {2019}, month = {Jan-07-2019}, pages = {57 - 72.e6}, abstract = {

The mammalian glycocalyx is a heavily glycosylated extramembrane compartment found on nearly every cell. Despite its relevance in both health and disease, studies of the glycocalyx remain hampered by a paucity of methods to spatially classify its components. We combine metabolic labeling, bioorthogonal chemistry, and super-resolution localization microscopy to image two constituents of cell-surface glycans,\ N-acetylgalactosamine (GalNAc) and sialic acid, with 10{\textendash}20\ nm precision in 2D and 3D. This approach enables two measurements: glycocalyx height and the distribution of individual sugars distal from the membrane. These measurements show that the glycocalyx exhibits nanoscale organization on both cell lines and primary human tumor cells. Additionally, we observe enhanced glycocalyx height in response to epithelial-to-mesenchymal transition and to oncogenic\ KRAS\ activation. In the latter case, we trace increased height to an effector gene,\ GALNT7. These data highlight the power of advanced imaging methods to provide molecular and functional insights into glycocalyx biology.

}, issn = {15345807}, doi = {10.1016/j.devcel.2019.04.035}, url = {https://www.sciencedirect.com/science/article/pii/S1534580719303326?via\%3Dihub}, author = {M{\"o}ckl, Leonhard and Pedram, Kayvon and Roy, Anish R. and Krishnan, Venkatesh and Gustavsson, Anna-Karin and Dorigo, Oliver and Bertozzi, Carolyn R. and Moerner, W.E.} } @article {65893, title = {Antibodies to biotin enable large-scale detection of biotinylation sites on proteins}, journal = {Nature Methods}, volume = {14}, year = {2017}, month = {Jan-12-2017}, pages = {1167 - 1170}, abstract = {

Although purification of biotinylated molecules is highly efficient, identifying specific sites of biotinylation remains challenging. We show that anti-biotin antibodies enable unprecedented enrichment of biotinylated peptides from complex peptide mixtures. Live-cell proximity labeling using APEX peroxidase followed by anti-biotin enrichment and mass spectrometry yielded over 1,600 biotinylation sites on hundreds of proteins, an increase of more than 30-fold in the number of biotinylation sites identified compared to streptavidin-based enrichment of proteins.

}, issn = {1548-7091}, doi = {10.1038/nmeth.4465}, url = {http://www.nature.com/articles/nmeth.4465http://www.nature.com/doifinder/10.1038/nmeth.4465http://www.nature.com/articles/nmeth.4465.pdfhttp://www.nature.com/articles/nmeth.4465.pdfhttp://www.nature.com/articles/nmeth.4465}, author = {Udeshi, Namrata D and Pedram, Kayvon and Svinkina, Tanya and Fereshetian, Shaunt and Myers, Samuel A and Aygun, Ozan and Krug, Karsten and Clauser, Karl and Ryan, Dominic and Ast, Tslil and Mootha, Vamsi K and Ting, Alice Y and Carr, Steven A} } @article {65894, title = {A bulky glycocalyx fosters metastasis formation by promoting G1 cell cycle progression}, journal = {eLife}, volume = {6}, year = {2017}, month = {Sep-12-2018}, abstract = {

Metastasis depends upon cancer cell growth and survival within the metastatic niche. Tumors which remodel their glycocalyces, by overexpressing bulky glycoproteins like mucins, exhibit a higher predisposition to metastasize, but the role of mucins in oncogenesis remains poorly understood. Here we report that a bulky glycocalyx promotes the expansion of disseminated tumor cells in vivo by fostering integrin adhesion assembly to permit G1 cell cycle progression. We engineered tumor cells to display glycocalyces of various thicknesses by coating them with synthetic mucin-mimetic glycopolymers. Cells adorned with longer glycopolymers showed increased metastatic potential, enhanced cell cycle progression, and greater levels of integrin-FAK mechanosignaling and Akt signaling in a syngeneic mouse model of metastasis. These effects were mirrored by expression of the ectodomain of cancer-associated mucin MUC1. These findings functionally link mucinous proteins with tumor aggression, and offer a new view of the cancer glycocalyx as a major driver of disease progression.

}, doi = {https://doi.org/10.7554/eLife.25752}, url = {https://elifesciences.org/articles/25752}, author = {Woods, Elliot C and Kai, FuiBoon and Barnes, J Matthew and Pedram, Kayvon and Pickup, Michael W and Hollander, Michael J and Weaver, Valerie M and Bertozzi, Carolyn R} } @article {65891, title = {Spatially resolved proteomic mapping in living cells with the engineered peroxidase APEX2}, journal = {Nature Protocols}, volume = {11}, year = {2016}, month = {Jan-03-2016}, pages = {456 - 475}, abstract = {

This protocol describes a method to obtain spatially resolved proteomic maps of specific compartments within living mammalian cells. An engineered peroxidase, APEX2, is genetically targeted to a cellular region of interest. Upon the addition of hydrogen peroxide for 1 min to cells preloaded with a biotin-phenol substrate, APEX2 generates biotin-phenoxyl radicals that covalently tag proximal endogenous proteins. Cells are then lysed, and biotinylated proteins are enriched with streptavidin beads and identified by mass spectrometry. We describe the generation of an appropriate APEX2 fusion construct, proteomic sample preparation, and mass spectrometric data acquisition and analysis. A two-state stable isotope labeling by amino acids in cell culture (SILAC) protocol is used for proteomic mapping of membrane-enclosed cellular compartments from which APEX2-generated biotin-phenoxyl radicals cannot escape. For mapping of open cellular regions, we instead use a {\textquoteright}ratiometric{\textquoteright} three-state SILAC protocol for high spatial specificity. Isotopic labeling of proteins takes 5{\textendash}7 cell doublings. Generation of the biotinylated proteomic sample takes 1 d, acquiring the mass spectrometric data takes 2{\textendash}5 d and analysis of the data to obtain the final proteomic list takes 1 week.

}, issn = {1754-2189}, doi = {10.1038/nprot.2016.018}, url = {http://www.nature.com/articles/nprot.2016.018http://www.nature.com/articles/nprot.2016.018.pdfhttp://www.nature.com/articles/nprot.2016.018.pdfhttp://www.nature.com/articles/nprot.2016.018}, author = {Hung, Victoria and Udeshi, Namrata D and Lam, Stephanie S and Loh, Ken H and Cox, Kurt J and Pedram, Kayvon and Carr, Steven A and Ting, Alice Y} } @article {66011, title = {Pediatric epilepsy surgery: long-term 5-year seizure remission and medication use}, journal = {Neurosurgery}, volume = {71}, year = {2012}, month = {Feb-08-2013}, pages = {985 - 993}, abstract = {

Background:\ It is unclear whether long-term seizure outcomes in children are similar to those in adult epilepsy surgery patients.

Objective:\ To determine 5-year outcomes and antiepilepsy drug (AED) use in pediatric epilepsy surgery patients from a single institution.

Methods:\ The cohort consisted of children younger than 18 years of age whose 5-year outcome data would have been available by 2010. Comparisons were made between patients with and without 5-year data (n = 338), patients with 5-year data for seizure outcome (n = 257), and seizure-free patients on and off AEDs (n = 137).

Results:\ Five-year data were available from 76\% of patients. More seizure-free patients with focal resections for hippocampal sclerosis and tumors lacked 5-year data compared with other cases. Of those with 5-year data, 53\% were continuously seizure free, 18\% had late seizure recurrence, 3\% became seizure free after initial failure, and 25\% were never seizure free. Patients were more likely to be continuously seizure free if their surgery was performed during the period 2001 to 2005 (68\%) compared with surgery performed from 1996 to 2000 (61\%), 1991 to 1995 (36\%), and 1986 to 1990 (46\%). More patients had 1 or fewer seizures per month in the late seizure recurrence (47\%) compared with the not seizure-free group (20\%). Four late deaths occurred in the not seizure-free group compared with 1 in the seizure-free group. Of patients who were continuously seizure free, 55\% were not taking AEDs, and more cortical dysplasia patients (74\%) had stopped taking AEDs compared with hemimegalencephaly patients (18\%).

Conclusion:\ In children, 5-year outcomes improved over 20 years of clinical experience. Our results are similar to those of adult epilepsy surgery patients despite mostly extratemporal and hemispheric operations for diverse developmental etiologies.

}, issn = {0148-396X}, doi = {10.1227/NEU.0b013e31826cdd5a}, url = {https://academic.oup.com/neurosurgery/article/71/5/985/2595469http://academic.oup.com/neurosurgery/article-pdf/71/5/985/32585196/00006123-201211000-00011.pdfhttp://academic.oup.com/neurosurgery/article-pdf/71/5/985/32585196/00006123-201211000-00011.pdf}, author = {Hauptman, Jason S. and Pedram, Kayvon and Sison, Christia Angela and Sankar, Raman and Salamon, Noriko and Vinters, Harry V. and Mathern, Gary W.} }