BCL2 expression is enriched in advanced prostate cancer with features of lineage plasticity.

The widespread use of potent androgen receptor signaling inhibitors (ARSIs) has led to an increasing emergence of AR-independent castration-resistant prostate cancer (CRPC), typically driven by loss of AR expression, lineage plasticity, and transformation to prostate cancers (PCs) that exhibit phenotypes of neuroendocrine or basal-like cells. The anti-apoptotic protein BCL2 is upregulated in neuroendocrine cancers and may be a therapeutic target for this aggressive PC disease subset. There is an unmet clinical need, therefore, to clinically characterize BCL2 expression in metastatic CRPC (mCRPC), determine its association with AR expression, uncover its mechanisms of regulation, and evaluate BCL2 as a therapeutic target and/or biomarker with clinical utility. Here, using multiple PC biopsy cohorts and models, we demonstrate that BCL2 expression is enriched in AR-negative mCRPC, associating with shorter overall survival and resistance to ARSIs. Moreover, high BCL2 expression associates with lineage plasticity features and neuroendocrine marker positivity. We provide evidence that BCL2 expression is regulated by DNA methylation, associated with epithelial-mesenchymal transition, and increased by the neuronal transcription factor ASCL1. Finally, BCL2 inhibition had antitumor activity in some, but not all, BCL2-positive PC models, highlighting the need for combination strategies to enhance tumor cell apoptosis and enrich response.

Pre-treatment with systemic agents for advanced NSCLC elicits changes in the phenotype of autologous T cell therapy products.

The antitumor activity of adoptive T cell therapies (ACT) is highly dependent on the expansion, persistence, and continued activity of adoptively transferred cells. Clinical studies using ACTs have revealed that products that possess and maintain less differentiated phenotypes, including memory and precursor T cells, show increased antitumor efficacy and superior patient outcomes owing to their increased expansion, persistence, and ability to differentiate into effector progeny that elicit antitumor responses. Strategies that drive the differentiation into memory or precursor-type T cell subsets with high potential for persistence and self-renewal will enhance adoptively transferred T cell maintenance and promote durable antitumor efficacy. Because of the high costs associated with ACT manufacturing, ACTs are often only offered to patients after multiple rounds of systemic therapy. An essential factor to consider in producing autologous ACT medicinal products is the impact of the patient's initial T cell fitness and subtype composition, which will likely differ with age, disease history, and treatment with prior anti-cancer therapies. This study evaluated the impact of systemic anti-cancer therapy for non-small cell lung cancer treatment on the T cell phenotype of the patient at baseline and the quality and characteristics of the genetically modified autologous T cell therapy product after manufacturing.