Medical Cell Biology Commons^™

Structure-Based Design Of Stapled Peptides That Bind Gabarap And Inhibit Autophagy, Hawley Brown, Mia Chung, Alina Üffing, Nefeli Batistatou, Tiffany Tsang, Samantha Doskocil, Weiqun Mao, Dieter Willbold, Robert C Bast, Zhen Lu, Oliver H Weiergräber, Joshua A Kritzer

Faculty, Staff and Student Publications

The LC3/GABARAP family of proteins is involved in nearly every stage of autophagy. Inhibition of LC3/GABARAP proteins is a promising approach to blocking autophagy, which sensitizes advanced cancers to DNA-damaging chemotherapy. Here, we report the structure-based design of stapled peptides that inhibit GABARAP with nanomolar affinities. Small changes in staple structure produced stapled peptides with very different binding modes and functional differences in LC3/GABARAP paralog selectivity, ranging from highly GABARAP-specific to broad inhibition of both subfamilies. The stapled peptides exhibited considerable cytosolic penetration and resistance to biological degradation. They also reduced autophagic flux in cultured ovarian cancer cells and sensitized …

A Method For Bridging Population-Specific Genotypes To Detect Gene Modules Associated With Alzheimer's Disease, Yulin Dai, Peilin Jia, Zhongming Zhao, Assaf Gottlieb

Faculty, Staff and Student Publications

BACKGROUND: Genome-wide association studies have successfully identified variants associated with multiple conditions. However, generalizing discoveries across diverse populations remains challenging due to large variations in genetic composition. Methods that perform gene expression imputation have attempted to address the transferability of gene discoveries across populations, but with limited success.

METHODS: Here, we introduce a pipeline that combines gene expression imputation with gene module discovery, including a dense gene module search and a gene set variation analysis, to address the transferability issue. Our method feeds association probabilities of imputed gene expression with a selected phenotype into tissue-specific gene-module discovery over protein interaction …

Alyref, A Novel Factor Involved In Breast Carcinogenesis, Acts Through Transcriptional And Post-Transcriptional Mechanisms Selectively Regulating The Short Neat1 Isoform, Christiane Klec, Erik Knutsen, Daniela Schwarzenbacher, Katharina Jonas, Barbara Pasculli, Ellen Heitzer, Beate Rinner, Katarina Krajina, Felix Prinz, Benjamin Gottschalk, Peter Ulz, Alexander Deutsch, Andreas Prokesch, Stephan W Jahn, S Mohammad Lellahi, Maria Perander, Raffaela Barbano, Wolfgang F Graier, Paola Parrella, George Adrian Calin, Martin Pichler

Faculty, Staff and Student Publications

The RNA-binding protein ALYREF (THOC4) is involved in transcriptional regulation and nuclear mRNA export, though its role and molecular mode of action in breast carcinogenesis are completely unknown. Here, we identified high ALYREF expression as a factor for poor survival in breast cancer patients. ALYREF significantly influenced cellular growth, apoptosis and mitochondrial energy metabolism in breast cancer cells as well as breast tumorigenesis in orthotopic mouse models. Transcriptional profiling, phenocopy and rescue experiments identified the short isoform of the lncRNA NEAT1 as a molecular trigger for ALYREF effects in breast cancer. Mechanistically, we found that ALYREF binds to the NEAT1 …

Targeting Syndecan-1: New Opportunities In Cancer Therapy, Zecheng Yang, Shuaitong Chen, Haoqiang Ying, Wantong Yao

Faculty, Staff and Student Publications

Syndecan-1 (SDC1, CD138) is one of the heparan sulfate proteoglycans and is essential for maintaining normal cell morphology, interacting with the extracellular and intracellular protein repertoire, as well as mediating signaling transduction upon environmental stimuli. The critical role of SDC1 in promoting tumorigenesis and metastasis has been increasingly recognized in various cancer types, implying a promising potential of utilizing SDC1 as a novel target for cancer therapy. This review summarizes the current knowledge on SDC1 structure and functions, including its role in tumor biology. We also discuss the highlights and limitations of current SDC1-targeted therapies as well as the obstacles …

Dedifferentiation-Mediated Stem Cell Niche Maintenance In Early-Stage Ductal Carcinoma In Situ Progression: Insights From A Multiscale Modeling Study, Joseph D Butner, Prashant Dogra, Caroline Chung, Javier Ruiz-Ramírez, Sara Nizzero, Marija Plodinec, Xiaoxian Li, Ping-Ying Pan, Shu-Hsia Chen, Vittorio Cristini, Bulent Ozpolat, George A Calin, Zhihui Wang

Faculty, Staff and Student Publications

We present a multiscale agent-based model of ductal carcinoma in situ (DCIS) to study how key phenotypic and signaling pathways are involved in the early stages of disease progression. The model includes a phenotypic hierarchy, and key endocrine and paracrine signaling pathways, and simulates cancer ductal growth in a 3D lattice-free domain. In particular, by considering stochastic cell dedifferentiation plasticity, the model allows for study of how dedifferentiation to a more stem-like phenotype plays key roles in the maintenance of cancer stem cell populations and disease progression. Through extensive parameter perturbation studies, we have quantified and ranked how DCIS is …

Development And Characterization Of Anti-Galectin-9 Antibodies That Protect T Cells From Galectin-9-Induced Cell Death, Riyao Yang, Linlin Sun, Ching-Fei Li, Yu-Han Wang, Weiya Xia, Boning Liu, Yu-Yi Chu, Laura Bover, Long Vien, Mien-Chie Hung

Faculty, Staff and Student Publications

Antibodies that target immune checkpoint proteins such as programmed cell death protein 1, programmed death ligand 1, and cytotoxic T-lymphocyte-associated antigen 4 in human cancers have achieved impressive clinical success; however, a significant proportion of patients fail to respond to these treatments. Galectin-9 (Gal-9), a β-galactoside-binding protein, has been shown to induce T-cell death and facilitate immunosuppression in the tumor microenvironment by binding to immunomodulatory receptors such as T-cell immunoglobulin and mucin domain-containing molecule 3 and the innate immune receptor dectin-1, suggesting that it may have potential as a target for cancer immunotherapy. Here, we report the development of two …

Cistrome And Transcriptome Analysis Identifies Unique Androgen Receptor (Ar) And Ar-V7 Splice Variant Chromatin Binding And Transcriptional Activities, Paul Basil, Matthew J Robertson, William E Bingman, Amit K Dash, William C Krause, Ayesha A Shafi, Badrajee Piyarathna, Cristian Coarfa, Nancy L Weigel

Faculty, Staff and Students Publications

The constitutively active androgen receptor (AR) splice variant, AR-V7, plays an important role in resistance to androgen deprivation therapy in castration resistant prostate cancer (CRPC). Studies seeking to determine whether AR-V7 is a partial mimic of the AR, or also has unique activities, and whether the AR-V7 cistrome contains unique binding sites have yielded conflicting results. One limitation in many studies has been the low level of AR variant compared to AR. Here, LNCaP and VCaP cell lines in which AR-V7 expression can be induced to match the level of AR, were used to compare the activities of AR and …

Interplay Between Soluble Cd74 And Macrophage-Migration Inhibitory Factor Drives Tumor Growth And Influences Patient Survival In Melanoma, Yasunari Fukuda, Matias A Bustos, Sung-Nam Cho, Jason Roszik, Suyeon Ryu, Victor M Lopez, Jared K Burks, Jeffrey E Lee, Elizabeth A Grimm, Dave S B Hoon, Suhendan Ekmekcioglu

Faculty, Staff and Student Publications

Soluble forms of receptors play distinctive roles in modulating signal-transduction pathways. Soluble CD74 (sCD74) has been identified in sera of inflammatory diseases and implicated in their pathophysiology; however, few relevant data are available in the context of cancer. Here we assessed the composition and production mechanisms, as well as the clinical significance and biological properties, of sCD74 in melanoma. Serum sCD74 levels were significantly elevated in advanced melanoma patients compared with normal healthy donors, and the high ratio of sCD74 to macrophage-migration inhibitory factor (MIF) conferred significant predictive value for prolonged survival in these patients (p = 0.0035). Secretion of …

A Human Breast Cancer-Derived Xenograft And Organoid Platform For Drug Discovery And Precision Oncology, Katrin P Guillen, Maihi Fujita, Andrew J Butterfield, Sandra D Scherer, Matthew H Bailey, Zhengtao Chu, Yoko S Derose, Ling Zhao, Emilio Cortes-Sanchez, Chieh-Hsiang Yang, Jennifer Toner, Guoying Wang, Yi Qiao, Xiaomeng Huang, Jeffery A Greenland, Jeffery M Vahrenkamp, David H Lum, Rachel E Factor, Edward W Nelson, Cindy B Matsen, Jane M Poretta, Regina Rosenthal, Anna C Beck, Saundra S Buys, Christos Vaklavas, John H Ward, Randy L Jensen, Kevin B Jones, Zheqi Li, Steffi Oesterreich, Lacey E Dobrolecki, Satya S Pathi, Xing Yi Woo, Kristofer C Berrett, Mark E Wadsworth, Jeffrey H Chuang, Michael T Lewis, Gabor T Marth, Jason Gertz, Katherine E Varley, Bryan E Welm, Alana L Welm

Faculty, Staff and Students Publications

Microscaled proteogenomics was deployed to probe the molecular basis for differential response to neoadjuvant carboplatin and docetaxel combination chemotherapy for triple-negative breast cancer (TNBC). Proteomic analyses of pretreatment patient biopsies uniquely revealed metabolic pathways, including oxidative phosphorylation, adipogenesis, and fatty acid metabolism, that were associated with resistance. Both proteomics and transcriptomics revealed that sensitivity was marked by elevation of DNA repair, E2F targets, G₂–M checkpoint, interferon-gamma signaling, and immune-checkpoint components. Proteogenomic analyses of somatic copy-number aberrations identified a resistance-associated 19q13.31–33 deletion where LIG1, POLD1, and XRCC1 are located. In orthogonal datasets, LIG1 (DNA ligase I) gene …

The Allergy Mediator Histamine Confers Resistance To Immunotherapy In Cancer Patients Via Activation Of The Macrophage Histamine Receptor H1, Hongzhong Li, Yi Xiao, Qin Li, Jun Yao, Xiangliang Yuan, Yuan Zhang, Xuedong Yin, Yohei Saito, Huihui Fan, Ping Li, Wen-Ling Kuo, Angela Halpin, Don L Gibbons, Hideo Yagita, Zhongming Zhao, Da Pang, Guosheng Ren, Cassian Yee, J Jack Lee, Dihua Yu

Faculty, Staff and Student Publications

Reinvigoration of antitumor immunity remains an unmet challenge. Our retrospective analyses revealed that cancer patients who took antihistamines during immunotherapy treatment had significantly improved survival. We uncovered that histamine and histamine receptor H1 (HRH1) are frequently increased in the tumor microenvironment and induce T cell dysfunction. Mechanistically, HRH1-activated macrophages polarize toward an M2-like immunosuppressive phenotype with increased expression of the immune checkpoint VISTA, rendering T cells dysfunctional. HRH1 knockout or antihistamine treatment reverted macrophage immunosuppression, revitalized T cell cytotoxic function, and restored immunotherapy response. Allergy, via the histamine-HRH1 axis, facilitated tumor growth and induced immunotherapy resistance in mice and humans. …

A Transgenic Bacterial Artificial Chromosome Approach To Identify Regulatory Regions That Direct Amhr2 And Osterix Expression In Müllerian Duct Mesenchyme, Malcolm M Moses, Rachel D Mullen, Daniel I Idowu, Peter Maye, Soazik P Jamin, Richard R Behringer

Faculty, Staff and Student Publications

A transgenic mouse approach using bacterial artificial chromosomes (BAC) was used to identify regulatory regions that direct Müllerian duct expression for Amhr2 and Osterix (Osx, also known as Sp7). Amhr2 encodes the receptor that mediates anti-Müllerian hormone (AMH) signaling for Müllerian duct regression in male embryos. Amhr2 is expressed in the Müllerian duct mesenchyme of both male and female embryos. A ∼147-kb BAC clone containing the Amhr2 locus was used to generate transgenic mice. The transgene was able to rescue the block in Müllerian duct regression of Amhr2-null males, suggesting that the BAC clone contains regulatory …

Regulation Of T Cell Function By Protein S-Acylation, Savannah J West, Darren Boehning, Askar M Akimzhanov

Faculty, Staff and Student Publications

S-acylation, the reversible lipidation of free cysteine residues with long-chain fatty acids, is a highly dynamic post-translational protein modification that has recently emerged as an important regulator of the T cell function. The reversible nature of S-acylation sets this modification apart from other forms of protein lipidation and allows it to play a unique role in intracellular signal transduction. In recent years, a significant number of T cell proteins, including receptors, enzymes, ion channels, and adaptor proteins, were identified as S-acylated. It has been shown that S-acylation critically contributes to their function by regulating protein localization, stability and protein-protein interactions. …

Soluble Angiotensin-Converting Enzyme 2, Cardiac Biomarkers, Structure, And Function, And Cardiovascular Events (From The Atherosclerosis Risk In Communities Study), Aliza Hussain, Olive Tang, Caroline Sun, Xiaoming Jia, Elizabeth Selvin, Vijay Nambi, Aaron Folsom, Gerardo Heiss, Faiez Zannad, Thomas Mosley, Salim S Virani, Josef Coresh, Eric Boerwinkle, Bing Yu, Jonathan W Cunningham, Amil M Shah, Scott D Solomon, James A De Lemos, Ron C Hoogeveen, Christie M Ballantyne

Faculty, Staff and Students Publications

Membrane-bound angiotensin-converting enzyme 2 is important in regulation of the renin-angiotensin-aldosterone system, but the association of cleaved soluble ACE2 (sACE2) with cardiovascular disease (CVD) is unclear. We evaluated the association of sACE2 with cardiac biomarkers, structure, and function and cardiovascular events in the Atherosclerosis Risk in Communities Study. sACE2 was measured in a subset of 497 participants (mean age 78±5.4 years, 53% men, 27% black); Cox regression analyses assessed prospective associations of sACE2 with time to first CVD event at median 6.1-year follow-up. sACE2 was higher in men, blacks, and participants with prevalent CVD, diabetes, or hypertension. Higher sACE2 levels …

Discovery And Characterization Of Bromodomain 2-Specific Inhibitors Of Brdt, Zhifeng Yu, Angela F Ku, Justin L Anglin, Rajesh Sharma, Melek Nihan Ucisik, John C Faver, Feng Li, Pranavanand Nyshadham, Nicholas Simmons, Kiran L Sharma, Sureshbabu Nagarajan, Kevin Riehle, Gundeep Kaur, Banumathi Sankaran, Marta Storl-Desmond, Stephen S Palmer, Damian W Young, Choel Kim, Martin M Matzuk

Faculty, Staff and Students Publications

Bromodomain testis (BRDT), a member of the bromodomain and extraterminal (BET) subfamily that includes the cancer targets BRD2, BRD3, and BRD4, is a validated contraceptive target. All BET subfamily members have two tandem bromodomains (BD1 and BD2). Knockout mice lacking BRDT-BD1 or both bromodomains are infertile. Treatment of mice with JQ1, a BET BD1/BD2 nonselective inhibitor with the highest affinity for BRD4, disrupts spermatogenesis and reduces sperm number and motility. To assess the contribution of each BRDT bromodomain, we screened our collection of DNA-encoded chemical libraries for BRDT-BD1 and BRDT-BD2 binders. High-enrichment hits were identified and resynthesized off-DNA and examined …

The Mitochondrial Protease Lonp1 Promotes Proteasome Inhibitor Resistance In Multiple Myeloma, Laure Maneix, Melanie A Sweeney, Sukyeong Lee, Polina Iakova, Shannon E Moree, Ergun Sahin, Premal Lulla, Sarvari V Yellapragada, Francis T F Tsai, Andre Catic

Faculty, Staff and Students Publications

Multiple myeloma and its precursor plasma cell dyscrasias affect 3% of the elderly population in the US. Proteasome inhibitors are an essential part of several standard drug combinations used to treat this incurable cancer. These drugs interfere with the main pathway of protein degradation and lead to the accumulation of damaged proteins inside cells. Despite promising initial responses, multiple myeloma cells eventually become drug resistant in most patients. The biology behind relapsed/refractory multiple myeloma is complex and poorly understood. Several studies provide evidence that in addition to the proteasome, mitochondrial proteases can also contribute to protein quality control outside of …