Abstract 3441
Background
Resistance to androgen receptor signaling is arguably the principal hallmark of lethal prostate cancer. Several mechanisms account for this resistance, including mutations in the AR, restoration of signaling downstream of the pharmacological blocking and activation of alternative oncogenic pathways.
Methods
We used the Nkx3.1CreERT2/+; Ptenfloxed/floxed; p53floxed/floxed (NPp53) mice that develop CRPC upon castration and undergo neuroendocrine differentiation with anti-AR treatment to isolate Enzalutamide resistance prostate cancer cells.
Results
Recently, we showed that activation of the chromatin remodeler Nsd2 is required for PCa metastasis and is strongly associated to tumor progression, and that its silencing markedly reduced the metastatic burden and increased survival. Our current data indicates that Nsd2 silencing sensitizes PCa cells to anti-AR treatment. Nsd2 KO using CRISPR/Cas9 resulted in a markedly enhanced efficacy of Enzalutamide and a significant reduction of AR transcriptional activity with either Enzalutamide or Abiraterone using two different reporter assays. Next, To identify Nsd2-dependent AR co-regulators we immunoprecipitated chromatin-bound endogenous AR in NPp53 cells and NPp53-Nsd2KO and performed nano-LC-MS/MS mass spectrometry on the purified peptide mix. In particular, data indicates that AR association with SWI/SNF members is stronger in the absence of Nsd2, suggesting that Nsd2 overexpression might impair AR interaction to the SWI/SNF complex. We next tested whether Nsd2 in fact binds SWI/SNF subunits by co-immunoprecipitation in the NPp53 cells and whether BAF155, BAF170 and BRG1 association to AR increases in the absence of Nsd2. As suspected, there is a remarkable increase in the binding of AR to SWI/SNF subunits BAF155, BAF170 and BRG1 in the absence of Nsd2.
Conclusions
Together, our data suggests that the mechanisms by which Nsd2 overexpression drives aggressive castration resistant and androgen independent PCa may be in part through destabilizing the AR-SWI/SNF interaction and altering the specificity of the AR cistrome. Ongoing work will further elucidate this by analyzing chromatin accessibility data coupled with transcriptomics and ChIPseq data for the AR and the BAF170, BAF155 and Brg1 SWI/SNF subunits.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Alvaro Aytes.
Funding
EAU.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
5437 - Salivary cytokines and oral mucosa cells apoptosis in patients during hematopoietic cell transplantation: possible relationship with oral mucositis
Presenter: Luciana Corrêa
Session: Poster Display session 1
Resources:
Abstract
1483 - A randomized trial of sodium alginate prevention of radiation-induced esophagitis in patients with locally advanced NSCLC receiving concurrent chemoradiotherapy: OLCSG1401
Presenter: Toshihide Yokoyama
Session: Poster Display session 1
Resources:
Abstract
2047 - Taste and smell alterations (TSAs) in patients (pts) with stage II-III colon cancer (CC): a pilot within the PROTECT study
Presenter: Jeroen Derksen
Session: Poster Display session 1
Resources:
Abstract
5984 - Clinical characteristics are associated with acupuncture treatment response for xerostomia in cancer patients
Presenter: Wenli Liu
Session: Poster Display session 1
Resources:
Abstract
2845 - Psychosocial Distress of Adolescent and Young Adults with Cancer at Diagnosis: A Case-Matched Retrospective Cohort of 2045 Patients in British Columbia.
Presenter: Alannah Smrke
Session: Poster Display session 1
Resources:
Abstract
724 - Accuracy of distress thermometer to measure cancer-related mood disorders in Chinese patients with cancer
Presenter: Sudip Thapa
Session: Poster Display session 1
Resources:
Abstract
2357 - Modalities of biosimilar filgrastim use in clinical practice in >1000 patients receiving chemotherapy regimens with a rest period of ≤14 days: the TOPAZE study
Presenter: Jean Marc Phelip
Session: Poster Display session 1
Resources:
Abstract
1426 - The Effect of Increasing Doses of Pegfilgrastim (Peg) on Thrombocytopenia (T) in Breast Cancer (BC) Patients (pts) Receiving Taxotere (Doc), Doxorubicin, Cyclophosphamide (TAC) and Plinabulin (Plin)
Presenter: Douglas Blayney
Session: Poster Display session 1
Resources:
Abstract
712 - The use of intravenous ferric carboxymaltose without erythropoiesis-stimulating agents in the treatment of anemia in cancer patients undergoing chemotherapy with or without radiotherapy
Presenter: Hikmat Abdel-Razeq
Session: Poster Display session 1
Resources:
Abstract
1496 - Randomized, double-blind, cross-over Phase I study comparing pharmacokinetics, pharmacodynamics, safety and immunogenicity of a biosimilar pegfilgrastim with EU and US references
Presenter: Maria Velinova
Session: Poster Display session 1
Resources:
Abstract