Prostate cancer (PCa) is the most frequently diagnosed malignancy in men, with a global incidence that continues to rise, accounting for nearly 29% of newly diagnosed male cancers in 2024 . While surgical intervention and radiotherapy provide effective treatment options for patients with localized PCa, in patients with advanced PCa, chemotherapy and immunotherapy have limited effectiveness. PCa is a typical "cold tumor", and the tumor-associated macrophages (TAMs) that maintain the immunosuppressive tumor microenvironment (TME) are the key bottleneck restricting immunotherapy. Based on this, this study proposes the core hypothesis that "the Notch-Rbpj pathway reshapes the pancreatic cancer immune microenvironment by regulating the polarization of monocyte-TAMs".

A monocyte tracer Rbpj conditional gene knockout mouse model was constructed. The knockout efficiency of mRNA and Rbpj protein were verified by qPCR and WB respectively. Model prostate cancer in situ in this mouse was established using PC-3 cells. After digestion of the tumors,flow cytometry was used to detect the knockdown efficiency of Rbpj in TAMs,and monocyte derived TAMs were sorted, and qPCR was used again to detect the knockdown efficiency of mRNA level.High-dimensional flow cytometry, multicolor immunofluorescence, and single-cell sequencing were used to examine the regulatory role of notching-RBPJ on the composition of the TAMs subpopulation in prostate cancer.

Prostate cancer TAMs have three groups of functional subpopulations with spatiotemporal heterogeneity. We found that the deletion of Rbpj in myeloid cells can delay tumor progression and improve the survival period of mice by inhibiting the Notch-Rbpj pathway and changing the proportion of TAM subgroups.

This study proposes the core hypothesis that "the Notch-Rbpj pathway reshapes the pancreatic cancer immune microenvironment by regulating the polarization of monocyte-TAMs".