Biology subjects

Chou, J.

Publications and source records attributed to Chou, J..

27 records · Page 2Linked to original sources

bioRxiv2022

Treatment of prostate cancer with CD46 targeted 225Ac alpha particle radioimmunotherapy

Radiopharmaceutical therapy is changing the standard of care in prostate cancer (PCa) and other malignancies. We previously reported high CD46 expression in PCa and developed an antibody-drug conjugate and immunoPET agent based on the YS5 antibody, which targets a tumor-selective CD46 epitope. Here, we present the preparation, preclinical efficacy, and toxicity evaluation of [225Ac]DOTA-YS5, a radioimmunotherapy agent based on the YS5 antibody. Our radiolabeled antibody retains binding efficacy and shows a high tumor to background ratio in PCa xenografts. Furthermore, we show that radiolabeled antibody was able to suppress the growth of cell-derived and patient-derived xenografts, including PSMA-positive and deficient models. Nephrotoxicity, not seen at low radioactive doses, is evident at higher radioactivity dose levels, likely due to redistribution of daughter isotope 213Bi. Overall, this preclinical study confirms that [225Ac]DOTA-YS5 is a highly effective treatment and suggests feasibility for clinical translation of CD46 targeted radioligand therapy in PCa.

cancer biology↗

bioRxiv2022

PICKLES v3: the updated database of pooled in vitro CRISPR knockout library essentiality screens

PICKLES (https://pickles.hart-lab.org) is an updated web interface to a freely available database of genome-scale CRISPR knockout fitness screens in human cell lines. Using a completely rewritten interface, researchers can explore gene knockout fitness phenotypes across cell lines and tissue types and compare fitness profiles with fitness, expression, or mutation profiles of other genes. The database has been updated to include data from three CRISPR libraries (Avana, Score, and TKOv3), and includes information from 1,162 whole-genome screens probing the knockout fitness phenotype of 18,959 genes. Source code for the interface and the integrated database are available for download.

bioinformatics↗

bioRxiv2022

BayesTME: A unified statistical framework for spatial transcriptomics

Spatial variation in cellular phenotypes underlies heterogeneity in immune recognition and response to therapy in cancer and many other diseases. Spatial transcriptomics (ST) holds the potential to quantify such variation, but existing analysis methods address only a small part of the analysis challenge, such as spot deconvolution or spatial differential expression. We present BayesTME, an end-to-end Bayesian method for analyzing spatial transcriptomics data. BayesTME unifies several previously distinct analysis goals under a single, holistic generative model. This unified approach enables BayesTME to (i) be entirely reference-free without any need for paired scRNA-seq, (ii) outperform a large suite of methods in quantitative benchmarks, and (iii) uncover a new type of ST signal: spatial differential expression within individual cell types. To achieve the latter, BayesTME models each phenotype as spatially adaptive and discovers statistically significant spatial patterns amongst coordinated subsets of genes within phenotypes, which we term spatial transcriptional programs. On human and zebrafish melanoma tissues, BayesTME identifies spatial transcriptional programs that capture fundamental biological phenomena like bilateral symmetry, differential expression between interior and surface tumor cells, and tumor-associated fibroblast and macrophage reprogramming. Our results demonstrate BayesTMEs power in unlocking a new level of insight from spatial transcriptomics data and fostering a deeper understanding of the spatial architecture of the tumor microenvironment. BayesTME is open source and publicly available (https://github.com/tansey-lab/bayestme).

bioinformatics↗

bioRxiv2021

CUB domain containing protein 1 (CDPC1) is a target for radioligand therapy in castration resistant prostate cancer

PurposeRadioligand therapy (RLT) is relatively unexplored in metastatic castration resistant prostate cancer (mCRPC), with much of the focus having been on bone seeking radionuclides and PSMA-directed RLT. Herein, we evaluated if CUB domain containing protein 1 (CDCP1) can be exploited to treat mCRPC with RLT, particularly for subsets like small cell neuroendocrine prostate cancer (SCNC) that would not be expected to respond to current options. Experimental DesignCDCP1 mRNA levels were evaluated in the RNA-seq data from 119 recent mCRPC biopsies. Protein expression was assessed in twelve SCNC and adenocarcinoma patient derived xenografts. Saturation binding assays were performed with 4A06, a recombinant human antibody that targets the CDCP1 ectodomain. The feasibility of imaging and treating mCRPC in vivo was tested with 89Zr-4A06 and 177Lu-4A06. ResultsCDCP1 mRNA expression was observed in over 90% of mCRPC biopsies, including SCNC and in adenocarcinoma with low FOLH1 (PSMA) levels. A modest anticorrelation was observed between CDCP1 and PTEN. Overall survival was not significantly different based on CDCP1 mRNA levels, regardless of PTEN status. Full length and/or cleaved CDCP1 was expressed in ten of twelve PDX samples. Bmax values of ~22,000 and ~6,200 fmol/mg were calculated for two human prostate cancer cell lines. Five prostate cancer models were readily detected in vivo with 89Zr-4A06. 177Lu-4A06 significantly suppressed the growth of DU145 tumors compared to control. ConclusionsThe antitumor data and the overexpression of CDCP1 reported herein provide the first evidence promoting CDCP1 directed RLT as a treatment strategy for mCRPC. Statement of Translational RelevanceNew targets for RLT are needed to address the subset of mCRPC that cannot be treated with bone seeking radionuclides or PSMA directed RLT. We report herein the first data credentialing CDCP1 as a target for mCRPC, in both adenocarcinoma and neuroendocrine subtypes. Combined with low expression in normal human tissues, these data provide a compelling scientific rationale for testing CDCP1 directed RLT clinically in mCRPC patients alone or in combination with other systemic therapies.

cancer biology↗

bioRxiv2021

Selective MAP1LC3C (LC3C) autophagy requires noncanonical initiation regulators and the paralog-specific C-terminal peptide

LC3s are canonical proteins necessary for the formation of autophagosomes. We have previously established that two paralogs, LC3B and LC3C, have opposite activities in renal cancer, with LC3B playing oncogenic role and LC3C tumor suppressing role. LC3C is an evolutionary late gene, present only in higher primates and humans. Its most distinct feature is a C-terminal 20 amino acid peptide cleaved in the process of glycine 126 lipidation. Here we investigated mechanisms of LC3C selective autophagy. LC3C autophagy requires noncanonical upstream regulatory complexes that include ULK3, UVRAG, RUBCN, PIK3C2A, and a member of ESCRT, TSG101. We established that Postdivision Midbody Rings (PDMBs) implicated in cancer stem cell regulation are direct targets of LC3C autophagy. LC3C C-terminal peptide is necessary and sufficient to mediate LC3C-dependent selective degradation of PDMBs. This work establishes a new noncanonical human-specific selective autophagic program relevant to cancer stem cells.

cancer biology↗

bioRxiv2020

Autoantibody landscape of advanced prostate cancer

Although the importance of T-cell immune responses is well appreciated in cancer, autoantibody responses are less well-characterized. Nevertheless, autoantibody responses are of great interest, as they may be concordant with T-cell responses to cancer antigens or predictive of response to cancer immunotherapies. We performed serum epitope repertoire analysis (SERA) on a total of 1,229 serum samples obtained from a cohort of 72 men with metastatic castration-resistant prostate cancer (mCRPC) and 1,157 healthy control patients to characterize the autoantibody landscape of mCRPC. Using whole-genome sequencing results from paired solid-tumor metastasis biopsies and germline specimens, we identified tumor-specific epitopes in 29 mutant and 11 non-mutant proteins. Autoantibody enrichments for the top candidate autoantigen (NY-ESO-1) were validated using ELISA performed on the prostate cancer cohort and an independent cohort of 106 patients with melanoma. Our study recovers antigens of known importance and identifies novel tumor-specific epitopes of translational interest in advanced prostate cancer. Statement of significanceAutoantibodies have been shown to inform treatment response and candidate drug targets in various cancers. We present the first large-scale profiling of autoantibodies in advanced prostate cancer, utilizing a new next-generation sequencing-based approach to antibody profiling to reveal novel cancer-specific antigens and epitopes. Disclosure of Potential Conflicts of InterestJJA reports receiving consulting income from Janssen Biotech and Merck and honoraria from Astellas for speakers fees. MR reports receiving commercial research support from Novartis, Johnson & Johnson, Merck, Astellas, and Medivation, and is a consultant/advisory board member for Constellation Pharmaceuticals, Amgen, Ambrx, Johnson & Johnson, and Bayer. A.R. has received honoraria from consulting with Amgen, Bristol-Myers Squibb, Chugai, Dynavax, Genentech, Merck, Nektar, Novartis, Roche and Sanofi, is or has been a member of the scientific advisory board and holds stock in Advaxis, Arcus Biosciences, Bioncotech Therapeutics, Compugen, CytomX, Five Prime, RAPT, ImaginAb, Isoplexis, Kite-Gilead, Lutris Pharma, Merus, PACT Pharma, Rgenix and Tango Therapeutics. FYF serves on the advisory board for Dendreon, EMD Serono, Janssen Oncology, Ferring, Sanofi, Blue Earth Diagnostics, Celgene, consults for Bayer, Medivation/Astellas, Genetech, and Nutcracker Therapeutics, has honoraria from Clovis Oncology, and is a founder and has an ownership stake in PFS Genomics. SGZ and FYF have patent applications with Decipher Biosciences. SGZ and FYF have a patent application licensed to PFS Genomics. SGZ and FYF have patent applications with Celgene. WAH, RW, KK, PSD, and JCS have ownership of stocks or shares at Serimmune, paid employment at Serimmune, board membership at Serimmune, and patent applications on behalf of Serimmune.

cancer biology↗

bioRxiv2020

The physical form of microbial ligands bypasses the need for dendritic cell migration to stimulate adaptive immunity

A central paradigm of immunology is that the innate immune system first detects infectious agents in peripheral tissues, shortly after a pathogen has breached an epithelial barrier. This detection event is mediated by pattern recognition receptors in phagocytes, which then migrate to draining lymph nodes (dLNs), where information of a microbial encounter is conveyed to T and B lymphocytes to generate adaptive immunity. Through the study of fungal moieties, we present data that challenge this model. We found that soluble fungal polysaccharides are immunosilent in the periphery, but become potent immunogens in the dLN. These ligands completely bypass the need of phagocyte migration and, instead, directly activate an immune response that is most similar to those that typify viral infections. These data establish a class of microbial products that violate a central tenet of the immunological lexicon and illustrate that the physical form (not just the chemical structure) impacts innate and adaptive immunity.

immunology↗

bioRxiv2019

The inhibition of cellular toxicity of amyloid-beta by dissociated transthyretin

The protective effect of transthyretin (TTR) on cellular toxicity of amyloid-beta (A{beta}) has been previously reported. TTR is a tetrameric carrier of thyroxine in blood and cerebrospinal fluid, whose pathogenic aggregation causes systemic amyloidosis. In contrast, many reports have shown that TTR binds amyloid-beta (A{beta}), associated with Alzheimers disease, alters its aggregation, and inhibits its toxicity both in vitro and in vivo. In this study, we question whether TTR amyloidogenic ability and its anti-amyloid inhibitory effect are associated. Our results indicate that the dissociation of the TTR tetramer, required for its amyloid pathogenesis, is also necessary to prevent cellular toxicity from A{beta} oligomers. These findings suggest that the A{beta} binding site of TTR may be hidden in its tetrameric form. Aided by computational docking and peptide screening, we identified a TTR segment that is capable of altering A{beta} aggregation and toxicity, mimicking TTR cellular protection. This segment inhibits A{beta} oligomer formation and also promotes the formation of non-toxic, non-amyloid, amorphous aggregates which are more sensitive to protease digestion. This segment also inhibits seeding of A{beta} catalyzed by A{beta} fibrils extracted from the brain of an Alzheimers patient. Our results suggest that mimicking the inhibitory effect of TTR with peptide-based therapeutics represents an additional avenue to explore for the treatment of Alzheimers disease. Significance statementThe pathological landmarks of Alzheimers disease are the formation of amyloid plaques and neurofibrillary tangles. Amyloid plaques contain fibrous structures made of aggregated amyloid-beta (A{beta}). In 1982, Shirahama and colleagues observed the presence of transthyretin (TTR) in these plaques. TTR is a tetrameric protein whose aggregation causes transthyretin amyloidosis. However, TTR protects A{beta} from aggregating and causing toxicity to neurons. In this study, we show that the dissociation of TTR tetramers is required to inhibit cellular toxicity caused by A{beta}. In addition, we identified a minimum segment of TTR that inhibits A{beta} aggregation and cellular toxicity by the formation of amorphous aggregates that are sensitive to proteases, similar to the natural effect of TTR found by others in vivo.

biochemistry↗

bioRxiv2019

A Drosophila metainflammation-blood tumor model links aspirin-triggered eicosanoid-like mediators to immune signaling

Accumulating data from epidemiologic studies are linking aspirins use to a decline in chronic and metabolic inflammation that underlies many human diseases including some cancers. Aspirin reduces cyclooxygenase-mediated pro-inflammatory prostaglandins and promotes the production of pro-resolution molecules. Aspirin also triggers the production of anti-inflammatory electrophilic mono-oxygenated lipid mediators implicated in human pathologies. With the goal of developing a model system for studying the mechanisms of aspirin in reducing inflammation, we investigated aspirins effects in fruit fly models of chronic inflammation. Ectopic Toll/NF-{kappa}B and JAK/STAT signaling in D. melanogaster results in an overproliferation of hematopoietic blood progenitors coupled with metabolic inflammation in adipocytes. We report that, like mammals, flies are sensitive to aspirin treatment and it modulates the Toll-NF-{kappa}B axis. Aspirin-treated mutants simultaneously experience reduction in metabolic inflammation, mitosis, ectopic immune signaling, and macrophage infiltration. Moreover, flies synthesize 13-HODE, and aspirin triggers 13-EFOX-L2 production in mutants. In such flies with ectopic immune signaling, providing 13-HODEs precursor linoleic acid or performing targeted knockdown of transcription factor STAT in inflammatory blood cells boosts 13-EFOX-L2 levels while decreasing metabolic inflammation. Thus, hematopoietic cells regulate metabolic inflammation in flies, and their effects can be reversed by pharmaceutical or dietary intervention, suggesting deep phylogenetic conservation in animals ability to resolve systemic inflammation and repair tissue damage. This model system brings the power of Drosophila genetics to bear on immuno-metabolic mechanisms that boost systemic health and healing, with the potential to identify new targets for the treatment of chronic diseases in humans.

immunology↗