Posts classified under: Faculty

Penn Epigenetics > Faculty

Brian C. Capell, M.D., Ph.D.

Contributions to Science

  • Demonstrated the first role for ferroptosis in epidermal differentiation and tumor suppression: Our recent studies have uncovered a potential link between the emerging form of programmed cell death known as ferroptosis and the execution of both epidermal differentiation and tumor suppression in the skin. Beyond identifying the mechanisms through which MLL4 (KMT2D) promotes differentiation and exerts its tumor suppressive functions, these studies have revealed evidence that ferroptosis may be the essential mechanism by which keratinocytes ultimately die and form the cornified envelope of the epidermal barrier. Given that numerous skin disorders are driven by dysregulated epidermal differentiation, combined with the ability to both pharmacologically induce and inhibit ferroptosis, these studies have provided proof of principal that ferroptosis modulation may a viable therapeutic strategy for a variety of skin disorders.

a.    Egolf S, Zou J, Anderson A, Simpson CL, Aubert Y, Prouty S, Ge K, Seykora JT, Capell BC. MLL4 mediates differentiation and tumor suppression through ferroptosis. Sci Adv. 2021 Dec 10;7(50):eabj9141. doi: 10.1126/sciadv.abj9141. Epub 2021 Dec 10. PMID: 34890228; PMCID: PMC8664260.

Research Interest

The Capell Lab seeks to understand epigenetic gene regulatory mechanisms, how they interface with metabolism and the immune system, and how when disrupted, they may contribute to disease, and in particular, cancer. By combining the incredible accessibility of human skin with the most cutting-edge techniques, we aim to identify therapeutic vulnerabilities in cancer, and novel targets to treat disease.

Erica Korb, Ph.D

Contribution to Science

The role of chromatin in neurodevelopmental disorders and disease.

Epigenetic regulation plays a critical role in many neurodevelopmental disorders, including Autism Spectrum Disorder (ASD). In particular, many such disorders are the result of mutations in genes that encode chromatin modifying proteins. However, while these disorders share many features, it is unclear whether they also share gene expression disruptions resulting from the aberrant regulation of chromatin. We examined 5 chromatin modifiers that are all linked to ASD despite their different roles in regulating chromatin. Using RNA-sequencing, we identified a transcriptional signature that is shared between multiple neurodevelopmental syndromes, helping to elucidate the link between epigenetic regulation and the underlying cellular mechanisms that result in ASD.

During the COVID-19 shut-down, we sought to apply our understanding of histone biology to better understand the ability of SARS-CoV-2 to evade the immune system. In rare cases, viral proteins dampen antiviral responses by mimicking critical regions of human histone proteins particularly those containing posttranslational modifications required for transcriptional regulation. We found that the SARS-CoV-2 protein encoded by ORF8 (Orf8) functions as a histone mimic of the ARKS motifs in histone 3. Orf8 is associated with chromatin, binds to numerous histone-associated proteins, and is itself acetylated at this site. Orf8 expression disrupts multiple critical histone post-translational modifications including H3K9ac, H3K9me3, and H3K27me3 and promotes chromatin compaction while Orf8. Further, SARS-CoV-2 infection in human cells and patient lung tissue cause these same disruptions to chromatin acting through the Orf8 histone mimic motif. These findings define a mechanism through which SARS-CoV-2 disrupts host cell epigenetic regulation.

In my postdoctoral work in the lab of Dr. C. David Allis, I studied Fragile X syndrome (FXS). FXS is the most common genetic cause of intellectual disability and autism and is caused by loss of function of fragile X mental retardation protein (FMRP). I found that a disproportionate number of FMRP targets encode transcriptional regulators, particularly chromatin-associated proteins. In addition, I discovered that the loss of FMRP results in widespread chromatin misregulation and aberrant transcription. Finally, I demonstrated that the small molecule inhibitor Jq1 which blocks chromatin binding of the BET family of proteins alleviated many of the transcriptional changes and behavioral phenotypes associated with FXS. Through this work, I elucidated a novel causative mechanism of epigenetic disruption underlying FXS and demonstrated that targeting transcription may provide new treatment approaches. This work was published in Cell and included in a patent.

  • Kee, J., Thudium, S., Renner, D.M., Glastad, K., Palozola, K., Zhang, Z., Li, Y., Lan, Y., Cesare, J., Poleshko, A., Kiseleva, A.A., Truitt, R., Cardenas-Diaz, F. L., Zhang, X., Xie, X., Kotton, D. N., Alysandratos, K. D., Epstein, J.A., Shi, P.Y., Yang, W., Morrisey, E., Garcia, B. A., Berger, S. L., Weiss, S. R., Korb, E. SARS-CoV-2 protein encoded by ORF8 contains a histone mimic that disrupts chromatin regulation. Nature. (PMC in progress)
  • Thudium S, Palozola K, L’Her E, Korb E. Identification of a transcriptional signature found in multiple models of ASD and related disorders. Genome Research. (PMC in progress)
  • Korb, E., Herre, M., Zucker-Scharff, I., Allis, C.D., Darnell, RB. 2017. Excess translation of epigenetic regulators contributes to Fragile X Syndrome and is alleviated by Bd4 inhibition. Cell. (PMC5740873)
  • Inquimbert, P., Moll, M., Latremoliere, A., Tong, C.K., Wang, J., Sheehan, G.F., Smith, B.M., Korb, E., Athie, M.C.P., Babaniyi, O., Ghasemlou, N., Yanagawa, Y., Allis, C.D., Hof, P.R., Scholz, J. 2018. NMDA Receptor activation underlies the loss of spinal dorsal horn neurons and the transition to persistent pain after peripheral nerve injury. Cell Rep. (PMC62761118)

Epigenetic regulation of information storage in the brain

While chromatin regulation is crucial for the mechanisms underlying memory formation, the role of many chromatin-associated proteins in the context of neuronal function remains unclear. During my postdoctoral fellowship, I focused on Brd4, which binds acetylated histones. Despite the increasing use of Brd4 inhibitors as therapeutics, it had never been examined in the brain. I found that specific synaptic signals which leads to enhanced binding of Brd4 to histones to activate transcription of key neuronal genes that underlie memory formation. The loss of Brd4 function affects synaptic protein content, which results in memory deficits in mice and decreases seizure susceptibility. Thus, Brd4 provides a critical and previously uncharacterized link between neuronal activation and the transcriptional responses that occur during memory formation. This work has implications for the use of BET inhibitors in clinical settings and in possible treatments for epilepsy.

I also contributed to work examining additional mechanisms linking epigenetic regulation of transcription to behavioral responses to experience. This work from our collaborators in the lab of Dr. Eric Nestler (Ichan School of Medicine at Mount Sinai), examined the role of the ACF chromatin remodeling complex in depression. I investigated mechanisms controlling activity-dependent changes in expression of ACF. Together, these projects advanced our understanding of the link between neuronal signaling and epigenetic regulation underlying animal behavior both in normal conditions and in the context of mental health disorders. Finally, as an independent investigator, we published a review on the links between chromatin and plasticity mechanisms in the brain.

  • Korb, E., Herre, M., Zucker-Scharff, I., Darnell, RB., Allis, C.D. 2015. BET protein Brd4 activates transcription in neurons and BET inhibitor Jq1 blocks memory in mice. Nat. Neuro. (PMC4752120)
  • Herre, M., Korb, E. The chromatin landscape of neuronal plasticity. Curr. Opin. Neurobiol. (PMID: 31174107)
  • Sun, H., Damez-Werno, D.M., Scobie, K.M., Shao, N., Dias, C., Rabkin, J., Koo, J.W., Korb, E., Bagot, R.C., Ahn, F.H., Cahill, M., Labonte, B., Mouzon, E., Heller, E.A., Cates, H., Golden, S.A., Gleason, K., Russo, S.J., Andrews, S., Neve, R., Kennedy, P.J., Maze, I., Dietz, D.M., Allis, C.D., Turecki, G., Varga-Weisz, P., Tamminga, C., Shen, L., Nestler. E.J. 2015. ACF chromatin remodeling complex mediates stress-induced depressive-like behavior. Nat. Med. (PMC4598281)

Linking the synapse to the nucleus.

During my graduate school research, I sought to elucidate previously unexamined mechanisms regulating learning and memory. I focused on a protein that is critical for memory formation and synaptic plasticity, the activity-regulated cytoskeletal protein. Arc expression is robustly induced by activity, and Arc protein localizes both to active synapses and the nucleus. While its synaptic function had been examined in great detail, it was not clear why or how Arc is localized to the nucleus. I identified distinct regions of Arc that control its localization, including a nuclear localization signal, a nuclear retention domain, and a nuclear export signal. Arc localization to the nucleus regulates transcription, PML nuclear bodies, synaptic strength, and homeostatic plasticity. This was the first demonstration that Arc was important in regulating transcription and one of the first indications that PML bodies play an important role in neurons.

Our lab has undertaken projects examining other pathways that link external signals to responses within the nucleus. As part of a collaboration with Dr. Steven Josefowicz at Weill Cornell Medical School, we examined a previously unexplored histone modification, histone H3.3 serine 31 phosphorylation (H3.3S31ph). We demonstrated that in neurons H3.3S31ph is rapidly and robustly induced in neurons in response to synaptic stimulation. This was critical in expanding finding to additional cell types and systems beyond an immune cell response and was recently published in Nature.

  • Korb, E., Wilkinson, C. L., Delgado, R.N., Lovero, K.L., Finkbeiner, S. 2013. Arc in the nucleus regulates PML-dependent GluA1 transcription and homeostatic plasticity. Nat. Neuro. 16(7), 874-83. (PMC3703835)
  • Korb, E., Finkbeiner, S. 2011. Arc in synaptic plasticity: from gene to behavior. Trends Neurosci. 34, 591-8. (PMC3207967)
  • Korb, E., Finkbeiner, S. 2013. PML in the Brain: From Development to Degeneration. Frontiers in Molecular and Cellular Oncology. 17, 242. (PMC3775456)
  • Armache, A., Yang, S., Martinez de Paz, A., Robbins, L.E., Durmaz, C., Yeong, J.Q., Ravishankar, A., Daman, A.W., Ahimovic, D.J., Klevorn, T., Yue, Y., Arslan, T., Lin, S., Panchenko, T., Hrit, J., Wang, M., Thudium, S., Garcia, B.A., Korb, E., Armache, K., Rothbart, S.B., Hake, S.B., Allis, C.D., Li H., Josefowicz, S.Z. 2020. Histone H3.3 phosphorylation amplifies stimulation-induced transcription. Nature. 583(7818), 852-857. (PMC75175895)

Research Interest

The Korb lab works at the intersection of neuroscience and epigenetics. Epigenetic regulation is extremely important in neuronal function and contributes to the creation of new memories, our ability to adapt to our environment, and numerous neurological disorders. We try to understand how the world around us can influence gene expression in our neurons to allow us to learn, adapt, and become the people we are today.
In the lab, we focus on chromatin and its role in neuronal function. Chromatin is the complex of DNA and proteins called histones, which package our DNA into complex structures and control access to our genes. To study the role of histones in neuronal function and in disorders such as autism, we combine methods such as microscopy, bioinformatics, biochemistry, behavioral testing, and more. We have multiple areas of research in the lab, all focused on the study of chromatin and how it regulates neuronal function and neurodevelopmental disorders.

George Burslem, Ph.D.

Contributions to Science

Targeted Protein Degradation
Approximately 75% of the proteome is considered undruggable by traditional small molecule inhibition approaches. As an LLS postdoctoral fellow at Yale, I contributed to the development and application of Proteolysis Targeting Chimera (PROTACs) – heterobifunctional small molecules which recruit an E3 ligase to a protein target, resulting in target ubiquitination and subsequent degradation via the proteasome. This enables small molecule induced degradation of disease relevant proteins in native systems including in vivo. One of my contributions was to expand this approach to transmembrane proteins (specifically receptor tyrosine kinases) which are not endogenously degraded via the proteasome but can be degraded in this manner under small molecule control. The PROTAC approach has also been applied to crucial targets (BCR-Abl and FLT-3 ITD) in hematological malignancies demonstrating the power of the PROTAC approach for drug discovery and revealing previously unknown scaffolding roles of these kinases.
– Proteolysis-Targeting Chimeras as Therapeutics and Tools for Biological Discovery, G.M. Burslem and C.M. Crews, Cell, 2020, 181, 102. PMCID: PMC7319047
– Targeting BCR-ABL1 in Chronic Myeloid Leukemia by PROTAC-mediated Targeted Protein Degradation, G.M. Burslem, A. Reister-Schultz, D.P. Bondeson, C. Eide, S. Savage, B. Druker and C.M. Crews, Cancer Research, 2019, 79. 4744. PMCID: PMC6893872
– Enhancing Antiproliferative Activity and Selectivity of a FLT-3 Inhibitor by Proteolysis Targeting Chimera Conversion, G.M. Burslem, J. Song, X. Chen, J. Hines and C.M. Crews, J. Am. Chem. Soc., 2018, 140, 16428. PMID: 30427680
– The Advantages of Targeted Protein Degradation over Inhibition: an RTK Case Study, G.M. Burslem, B.E. Smith, A. Lai, S. Jaime-Figueroa, D. McQuaid, D.P. Bondeson, M. Toure, H. Dong, Y. Qian, J. Wang, A.P. Crew, J. Hines and C. M. Crews, Cell Chemical Biology, 2018, 25, 67. PMCID: PMC5777153

HIF-1α/p300 Inhibition
Mammalian cells have developed an elaborate pathway for oxygen sensing with a key player in this pathway being hypoxia inducible factor 1α (HIF-1α). Under hypoxic conditions, HIF-1α accumulates, heterodimerizes and translocated to the nucleus where it forms a protein-protein interaction with p300. This complex is transcriptionally active resulting in the hypoxic response and resupply of oxygen to the hypoxic tissue. This pathway is crucial for growth and development but is also exploited by solid tumors to enable growth to continue after exhaustion of their oxygen supply. As a graduate student, I focused on elucidating the molecular recognition between HIF-1α and p300 using biophysical and biochemical approaches before applying that knowledge to develop the first biophysically characterized inhibitors of this protein-protein interaction. Furthermore, this project led to the identification of novel peptide and protein aptamer inhibitors of the HIF-1α/p300 interaction via phage display and a novel class of chemical probes which incorporates both natural and unnatural recognition elements to provide enhanced selectivity and potency.
– Hypoxia Inducible Factor as a Model for Studying Inhibition of Protein-Protein Interactions, G.M. Burslem, H.F. Kyle, A.S. Nelson, T.A. Edwards, A.J. Wilson, Chemical Science, 2017, 8, 4188. PMCID: PMC5576430
– Towards “Bionic” Proteins: Replacement of Continuous Sequences from HIF-1α with Proteomimetics to Create Functional p300 Binding HIF-1α Mimics, G.M. Burslem, H.F. Kyle, A. L. Breeze, T.A. Edwards, S.L. Warriner, A. S. Nelson and A.J. Wilson, Chem. Commun., 2016, 52, 5421. PMCID: PMC4843846
– Small molecule proteomimetic inhibitors of the HIF-1α/p300 protein-protein interaction, G.M. Burslem, H. Kyle, A. Breeze, T.A. Edwards, A. Nelson, S.L. Warriner and A.J. Wilson, ChemBioChem, 2014, 15, 1083. PMCID: PMC4159589
– Exploration of the HIF-1α/p300 binding interface using peptide and adhiron phage display technologies to locate binding hot-spots for inhibitor development, H. F. Kyle, K. F. Wickson, J. Stott, G. M. Burslem, A. L. Breeze, D. C. Tomlinson, S. L. Warriner, A. Nelson, A. J. Wilson and T. A. Edwards, Mol. Biosyst., 2015, 11, 2738. PMID: 26135796

Modulating Protein-Protein Interactions
There are an estimated 650,000 pairwise protein-protein interactions in the human interactome and these interactions are implicated in all biological pathways. As such, the ability to modulate protein-protein interactions with chemical probes can provide unique insights in the functional roles of proteins and their binding partners. Over my career I have developed chemical biology approaches to both inhibit and induce protein-protein interactions as tool compounds and therapeutic approaches. An attractive approach to the inhibition of protein-protein interactions is to develop molecules which mimic a portion of one of protein binding partners and thus preferentially occupy the binding site on the other. Peptides are capable of doing this but must pay a significant entropic penalty to adopt the required conformation due to their inherent flexibility. One approach to combat this is to pre-organize the peptide into the desired conformation by chemically “stapling” it. Another approach is to develop small molecule mimetics capable of recapitulating the recognition elements of a protein/peptide but with less conformational flexibility. I have applied both of these techniques to generate inhibitors of a variety of protein-protein interactions including p53/hDM2, Bcl-XL/BID and RNase S-peptide/S-protein. Furthermore, protein-protein interactions can be induced by small molecules known as molecular glues which we have employed to stabilize interactions between Cereblon and IKZF1. We have also demonstrated the ability to induce protein-protein interactions between various proteins using heterobifunctional compounds.
– Double Quick, Double “Click” Reversible Peptide “Stapling”, C.M. Grison, G.M. Burslem, J.A. Miles, L. Pilsl, D.J. Yeo, S.L. Warriner, M. E. Webb and A. J. Wilson, Chemical Science, 2017, 8, 5166. PMCID: PMC5618791
– Synthesis of Highly Functionalized Oligobenzamide Proteomimetic Foldamers by Late-Stage Introduction of Sensitive Groups, G.M. Burslem, H.F. Kyle, P. Prabhakaran, A. L. Breeze, T.A. Edwards, S.L. Warriner, A. Nelson and A.J. Wilson, Org. Biomol. Chem. 2016, 14, 3782. PMCID: PMC4839272
– Efficient Synthesis of Immunomodulatory Drug Analogues Enables Exploration of Structure Degradation Relationships. G.M. Burslem*, P. Ottis, S. Jaime-Figueroa, A. Morgan, P.M. Cromm, M. Toure and C.M. Crews*, ChemMedChem, 2018, 12, 1508 (*Co-corresponding authors). PMCID: PMC6291207
– Lessons on Selective Degradation with a Promiscuous Warhead: Informing PROTAC Design, D.P. Bondeson, B.E. Smith, G.M. Burslem, A.D. Buhimschi, J. Hines, S. Jaime-Figueroa, J. Wang, B. Hamman, A. Ishchenko, C.M. Crews, Cell Chemical Biology, 2018, 25, 78. PMCID: PMC5777153

Epigenetic Chemical Biology
Epigenetic drug discovery provides a wealth of opportunities for the discovery of new therapeutics but has been hampered by low hit rates, frequent identification of false-positives, and poor synthetic tractability. Since establishing my laboratory at the University of Pennsylvania, we have endeavored to remedy the low hit rate in drug discovery efforts against epigenetic targets, by careful chemo-informatic analysis of active compounds and screening libraries. We have used the information gathered in these analysis to inform the design and synthesis of privileged compound collections for epigenetic chemical biology and probe discovery.
– Photochemical Synthesis of an Epigenetic Focused Tetrahydroquinoline Library, A.I. Green and G.M. Burslem, RSC Medicinal Chemistry, 2021, DOI: 10.1039/D1MD00193K
– Focused Libraries for Epigenetic Drug Discovery: The Importance of Isosteres, A.I. Green and G.M. Burslem, J. Med. Chem, 2021, 64, 7231-7240. PMID: 34042449
– Advances and Opportunities in Epigenetic Chemical Biology, J. Beyer, N. Raniszewski and G.M. Burslem, ChemBioChem, 2021, 22, 17-42. PMID: 32786101

Research Interest

The Burslem lab is interested in developing chemical tools to understand and modulate lysine post-translational modifications, specifically acetylation and ubiquitination. The laboratory is particularly interested in novel pharmacological approaches to modulate post-translational modifications which regulate gene expression and protein stability.

Colin Conine, Ph.D.

Contributions to Science

While studying sperm small RNA in mice, I discovered that RNAs are shipped from the epididymis to maturing sperm via extracellular vesicles, establishing a novel soma-to-germline transfer of RNA in mammals. This transfer of RNAs from epididymis to sperm is important for embryonic development as embryos fertilized by early epididymal sperm exhibit altered embryonic gene expression and fail to develop to term. Remarkably, both the molecular gene expression and embryonic viability phenotypes are rescued when early epididymal sperm embryos are injected with miRNAs acquired as sperm transit the epididymis.
Conine CC, Sun F, Song L, Rivera-Pérez JA, Rando OJ. MicroRNAs Absent in Caput Sperm Are Required for Normal Embryonic Development. Dev Cell. 2019 Jul 1;50(1):7-8. PubMed PMID: 31265813.
Conine CC, Sun F, Song L, Rivera-Pérez JA, Rando OJ. Small RNAs Gained during Epididymal Transit of Sperm Are Essential for Embryonic Development in Mice. Dev Cell. 2018 Aug 20;46(4):470-480.e3. PubMed Central PMCID: PMC6103825.
Lee G, Conine CC. The Transmission of Intergenerational Epigenetic Information by Sperm microRNAs. Epigenomes. 2022 April 07; 6(2):12-20. PubMed PMID: 35466187.

Research Interest

The functions of noncoding RNAs in fertility, epigenetic inheritance, and development

Liling-Wan

Liling Wan, Ph.D.

Contribution to Science

Molecular link between histone acetylation and oncogenic gene activation Histone acetylation is a chromatin mark generally associated with gene activation, yet the molecular mechanisms underlying this correlative relationship remain incompletely understood. I led a collaborative study in which we identified a novel ‘reader’ for histone acetylation named ENL. We showed in leukemia cells that ENL interacts with histone acetylation via the well-conserved YEATS domain, and in so doing, helps to recruit and stabilize its associated transcriptional machinery to drive transcription of leukemogenic genes. By determining the structure of ENL in complex with an acetylated histone peptide, we and our collaborators demonstrated that disrupting the reader function reduced chromatin recruitment of ENL-associated transcriptional machinery and resulted in suppression of oncogenic programs. Furthermore, blocking the functionality of ENL sensitized leukaemia cells to inhibitors that target another distinct class of histone acetylation readers, the BET proteins, thus highlighting the crosstalk between epigenetic readers and potential benefit of combinatorial therapies. Our work established ENL as a missing molecular link between histone acetylation and gene activation critical for leukemia malignant state, and has inspired following studies investigating other YEATS domain-containing proteins as a new class of chromatin ‘readers’ in a broad range of human cancers. In addition to bringing novel insights into our basic understanding of chromatin regulation, this work also provides mechanistic guidance and structural basis for ongoing drug development to target chromatin reading activity of ENL in aggressive leukemias.

Wan L#, Wen H#, Li Y#, Lyu J, Xi Y, Hoshii T, Joseph JK, Wang X, Loh YE, Erb MA, Souza AL, Bradner JE, Shen L, Li W, Li H*, Allis CD*, Armstrong SA*, Shi X*. ENL Links Histone Acetylation to Oncogenic Gene Activation in Leukemias. Nature 2017 Mar 9;543(7644):265-269. (#Equal contribution). PMC5372383
Li Y*, Sabari BR*, Panchenko T*, Wen H, Zhao D, Guan H, Wan L, Huang H, Tang Z, Zhao Y, Roeder RG, Shi X, Allis CD, Li H. Molecular Coupling of Histone Crotonylation and Active Transcription by AF9 YEATS Domain. Mol Cell2016 Apr 21;62(2):181-93. (*Equal contribution) PMC4841940

New type of gain-of-function mutations in chromatin readers Recognition of modified histones by ‘reader’ proteins constitutes a key mechanism mediating the function of histone modifications, yet the mechanisms by which their dysregulation contributes to diseases remain poorly understood. Recurrent, hotspot mutations in the acetylation-reading domain (YEATS domain) of ENL were recently found in Wilms’ tumor, the most common type of pediatric kidney cancer. Whether and how these mutations cause the disease remained unknown. Our current work shows that these mutations confer ENL gain of function in driving abnormal gene expression implicated in cancer. Unexpectedly, these mutations promoted ENL self-association, resulting in the formation of discrete nuclear puncta that are characteristic of biomolecular condensates, a newly recognized form of protein assembly that often involves weak, multivalent molecular interactions and commonly underlies the formation of membrane-less organelles. We demonstrated that such a property drives ‘self-reinforced’ chromatin targeting of mutant ENL protein and associated transcriptional machinery, thus enforcing active transcription from target loci. Aberrant gene control driven by ENL mutations, in turn, perturbs developmental programs and derails normal cell fate to a path towards tumorigenesis. This work is a remarkable demonstration of how mistakes in chromatin reader-mediated process can act as a driving force for tumor formation. These mutations represent a new class of oncogenic mutations which impair cell fate through promoting self-association and reinforcing chromatin targeting.

Wan L#, Chong S, Fan X, Liang A, Cui X, Gates L, Carroll TS, Li Y, Feng L, Chen G, Wang S, Ortiz MV, Daley S, Wang X, Xuan H, Kentsis A, Muir TW, Roeder RG, Li H, Li W, Tjian R, Wen H#, Allis CD#. Impaired Cell Fate through Gain-of-function Mutations in a Chromatin Reader. Nature 2019 in press (#co-corresponding)

Targeting chromatin readers as cancer therapies My postdoctoral work suggested that the displacement of histone acetylation reader ENL from chromatin may be a promising epigenetic therapy, alone or in combination with BET inhibitors, for aggressive leukemia. I have contributed to the development of peptidomimetic and small molecule inhibitors targeting the YEATS domain protein family. The ultimate goal of these and other ongoing efforts is to develop chemical probes targeting the ‘reading’ activity of ENL and other family members as valuable research tools and potential therapeutic agents.

Li X*, Li XM*, Jiang Y, Liu Z, Cui Y, Fung K, van der Beelen S, Tian G, Wan L, Shi X, Allis CD, Li H, Li Y#, Li X#. Structure-guided Development of YEATS Domain Inhibitors by Targeting π-π-π Stacking. Nat Chem Biol. 2018 Dec;14(12):1140-1149. (*Equal contribution) PMC6503841

Molecular mechanisms of cancer metastasis Metastasis accounts for > 90% cancer-related deaths and yet is the most poorly understood aspect of cancer biology. I have contributed to studies in which we identified and characterized new molecular mechanisms for cancer metastasis. My graduate work focused on Metadherin (MTDH), a novel cancer gene identified by our group to be prevalently amplified in breast cancer and strongly associated with a high risk of metastasis and poor prognosis. What drives the strong selection of MTDH in primary tumors was unclear. By generating genetically engineered mouse models, we provided first evidence supporting an essential role of MTDH in the initiation and metastasis of diverse subtypes of breast cancer. We further showed that MTDH regulates the expansion and activity of cancer stem cells through working with its binding partner SND1. By determining the atomic structure of the complex via collaboration, we demonstrated that disrupting the complex impairs breast cancer development and metastasis in vivo. Our work establishes MTDH and SND1 as critical regulators of cancer development and provides mechanistic guidance for ongoing drug development efforts to target this complex as cancer therapy. More broadly, this work provides crucial experimental support for the emerging concept that metastatic potential could be conferred by early oncogenic events that possess additional metastasis-promoting function and advances our understanding of the origin of metastatic traits.

Wan L, Lu X, Yuan S, Wei Y, Guo F, Shen M, Yuan M, Chakrabarti R, Hua Y, Smith HA, Blanco MA, Chekmareva M, Wu H, Bronson RT, Haffty BG, Xing Y, Kang Y. MTDH-SND1 Interaction Is Crucial for Expansion and Activity of Tumor-Initiating Cells in Diverse Oncogene- and Carcinogen-Induced Mammary Tumors. Cancer Cell 2014 Jul 14;26(1):92-105. PMC4101059
Wan L, Pantel K, Kang Y. Tumor Metastasis: Moving New Biological Insights into the Clinic. Nature Medicine 2013 Nov;19(11):1450-64. PMID: 24202397
Guo F#, Wan L#, Zheng A, Stanevich V, Wei Y, Satyshur KA, Shen M, Lee W, Kang Y, Xing Y. Structural Insights into the Tumor-Promoting Function of the MTDH-SND1 Complex. Cell Reports 2014 Sep 25;8(6):1704-13.  (#Equal contribution). PMC4309369
Wan L, Hu G, Wei Y, Yuan M, Bronson RT, Yang Q, Siddiqui J, Pienta KJ, Kang Y. Genetic Ablation of Metadherin Inhibits Autochthonous Prostate Cancer Progression and Metastasis. Cancer Research 2014 Sep 15;74(18):5336-47. PMC4167565
Kang Y, Xing Y, Wan L, Guo F. Use of peptides that block metadherin-SND1 interaction as treatment for cancer. (U.S. Patent No. 10,357,539 B2).

Research Interest

The research interests in our laboratory lie in the intersection of cancer biology and epigenetics. We focus on chromatin – the complex of DNA and histone proteins – and its regulatory network. Cancer genome studies revealed that at least 50% of human cancers harbor mutations in genes encoding chromatin-associated factors, suggesting widespread roles of chromatin misregulation in cancer. We strive to understand chromatin function and its dysregulation in human cancer, with a focus on addressing how chromatin-based mechanisms regulate cellular fate transition and plasticity that endow cancer cells with tumor-promoting potentials. We use a host of different approaches in genetics, epigenetics, biochemistry, genome-wide sequencing, bioinformatics and functional genomics to address these questions. We are also interested in leveraging our basic mechanistic discoveries for therapeutics development.

Giovanna Cruet

Contact Information

The Perelman School of Medicine at the University of Pennsylvania Department of Cell and Developmental Biology 9-123 Smilow Center for Translational Research 3400 Civic Center Blvd Philadelphia, PA 19104-6059 giovanna.cruet@pennmedicine.upenn.edu

Jennifer M. Kalish, M.D., Ph.D.

Attending Physician, Children’s Hospital of Philadelphia, Division of Genetics
Research Scientist, Children’s Hospital of Philadelphia, Center for Childhood Cancer Research
Director , Beckwith-Wiedemann Syndrome Clinic, Children’s Hospital of Philadelphia
Director, Program of Excellence in Beckwith-Wiedemann Syndrome, Orphan Disease Center, University of Pennsylvania

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