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Abstract N-Myc is a key driver of neuroblastoma and neuroendocrine prostate cancer (NEPC). One potential way to circumvent the challenge of undruggable N-Myc is to target the protein homeostasis (proteostasis) system that maintains N-Myc levels. Here, we identify heat shock protein 70 (HSP70) as a top partner of N-Myc, which binds a conserved “SELILKR” motif and prevents the access of E3 ubiquitin ligase, STIP1 homology and U-box containing protein 1 (STUB1), possibly through steric hindrance. When HSP70’s dwell time on N-Myc is increased by treatment with the HSP70 allosteric inhibitor, STUB1 is in close proximity with N-Myc and becomes functional to promote N-Myc ubiquitination on the K416 and K419 sites and forms polyubiquitination chains linked by the K11 and K63 sites. Notably, HSP70 inhibition significantly suppressed NEPC tumor growth, increased the efficacy of aurora kinase A (AURKA) inhibitors, and limited the expression of neuroendocrine-related pathways.

Objectives: Perioperative blood transfusion (PBT) has been associated with worse survival after radical cystectomy (RC) in patients with muscle-invasive bladder cancer (MIBC). Here, we evaluated the association between PBT and survival after RC that was preceded by neoadjuvant chemotherapy (NAC). Methods: A retrospective analysis was performed on 949 patients with cT2-4aN0M0 bladder cancer who received NAC prior to RC between 2000 and 2013 at 19 centers. Kaplan–Meier estimates of overall survival (OS) were made. Presumed risk factors for OS were analyzed using Cox regression analysis. PBT was defined by the administration of any packed red blood cells during surgery or during the post-operative hospital stay. Results: A transfusion was given to 608 patients (64%). Transfused patients were more likely to have adverse clinical and pathologic parameters, including clinical stage and performance status. Transfused patients had worse OS (p = 0.01). On multivariable Cox regression, PBT was found to be independently associated with worse OS (HR 1.53 (95% CI 1.13–2.08), p = 0.007). Conclusions: PBT is common after NAC and RC, which may be linked, in part, to the anemia induced by NAC. PBT was associated with several adverse risk factors that correlate with poor outcomes after NAC and RC, and it was an independent predictor of adverse OS on multivariable analysis. Further study should determine if measures to avoid blood loss can reduce the need for PBT and thereby improve patient outcomes.