Dataset Information

Targeting CD46 for both adenocarcinoma and neuroendocrine prostate cancer.

ABSTRACT: Although initially responsive to androgen signaling inhibitors (ASIs), metastatic castration-resistant prostate cancer (mCRPC) inevitably develops and is incurable. In addition to adenocarcinoma (adeno), neuroendocrine prostate cancer (NEPC) emerges to confer ASI resistance. We have previously combined laser capture microdissection and phage antibody display library selection on human cancer specimens and identified novel internalizing antibodies binding to tumor cells residing in their tissue microenvironment. We identified the target antigen for one of these antibodies as CD46, a multifunctional protein that is best known for negatively regulating the innate immune system. CD46 is overexpressed in primary tumor tissue and CRPC (localized and metastatic; adeno and NEPC), but expressed at low levels on normal tissues except for placental trophoblasts and prostate epithelium. Abiraterone- and enzalutamide-treated mCRPC cells upregulate cell surface CD46 expression. Genomic analysis showed that the CD46 gene is gained in 45% abiraterone-resistant mCRPC patients. We conjugated a tubulin inhibitor to our macropinocytosing anti-CD46 antibody and showed that the resulting antibody-drug conjugate (ADC) potently and selectively kills both adeno and NEPC cell lines in vitro (sub-nM EC50) but not normal cells. CD46 ADC regressed and eliminated an mCRPC cell line xenograft in vivo in both subcutaneous and intrafemoral models. Exploratory toxicology studies of the CD46 ADC in non-human primates demonstrated an acceptable safety profile. Thus, CD46 is an excellent target for antibody-based therapy development, which has potential to be applicable to both adenocarcinoma and neuroendocrine types of mCRPC that are resistant to current treatment.

SUBMITTER: Su Y

PROVIDER: S-EPMC6171802 | biostudies-other | 2018 Sep

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

Targeting CD46 for both adenocarcinoma and neuroendocrine prostate cancer.

Su Yang Y Liu Yue Y Behrens Christopher R CR Bidlingmaier Scott S Lee Nam-Kyung NK Aggarwal Rahul R Sherbenou Daniel W DW Burlingame Alma L AL Hann Byron C BC Simko Jeffry P JP Premasekharan Gayatri G Paris Pamela L PL Shuman Marc A MA Seo Youngho Y Small Eric J EJ Liu Bin B

JCI insight 20180906 17

Although initially responsive to androgen signaling inhibitors (ASIs), metastatic castration-resistant prostate cancer (mCRPC) inevitably develops and is incurable. In addition to adenocarcinoma (adeno), neuroendocrine prostate cancer (NEPC) emerges to confer ASI resistance. We have previously combined laser capture microdissection and phage antibody display library selection on human cancer specimens and identified novel internalizing antibodies binding to tumor cells residing in their tissue m ...[more]

PMID: 30185663

Similar Datasets

Project description:Histone deacetylation is crucial for the regulation of chromatin structure, gene transcription and the epigenetic state of the cell. With the emergence of the neuroendocrine (NE) phenotype in castration-resistant prostate cancer (CRPC), we hypothesized that the inhibition of HDAC1/2 would disrupt the epigenetic events involved in the conversion of prostate adenocarcinoma to a NE prostate cancer (NEPC) phenotype. Additionally, monotherapies tend to have limited efficacy in cancer treatment and combination treatments show more promise. Since the PI3K/AKT/mTOR pathway is a well-established tumor growth-promoting pathway and a promising target in CRPC and NEPC, we investigated the tumor suppressing activities of fimepinostat, a dual HDAC and PI3K inhibitor, on both prostate adenocarcinoma and NEPC. We evaluated multiple cell lines and patient-derived xenograft (PDX) models of prostate adenocarcinoma and NEPC to determine the roles of HDAC1/2 and AKT inhibition, both individually and in combination, in suppressing CRPC and NEPC tumor growth in vitro and in vivo. HDAC1/2 inhibition in combination with PI3K/AKT inhibition was more efficacious than targeting each pathway alone, induced growth inhibitory effects (in some cases synergistic) through cell cycle inhibition and apoptosis across an array of prostate adenocarcinoma and NEPC patient-derived xenografts (PDX) and cell lines in vitro and in vivo. Molecular profiling revealed on-target effects of combined HDAC1/2 and PI3K/AKT inhibition as well as a common downregulation of Myc, E2F, DNA repair, and G2M checkpoint targets, independent of prostate cancer phenotype. Fimepinostat therapy was also associated with the suppression of lineage transcription factor expression including androgen receptor (AR) in prostate adenocarcinoma and Achaete-scute homolog 1 (ASCL1) in NEPC. Our findings demonstrate that dual HDAC1/2 and PI3K/AKT pathway inhibition leads to robust tumor growth inhibition in both adenocarcinoma and NEPC, suggesting that fimepinostat may represent a novel therapeutic for both prostate adenocarcinoma and NEPC phenotypes of CRPC.

Dataset Information

Targeting CD46 for both adenocarcinoma and neuroendocrine prostate cancer.

Publications

Targeting CD46 for both adenocarcinoma and neuroendocrine prostate cancer.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets