Mechanism Of Neuroendocrine Differentiation Of Prostate Cancer Based On Single Cell Sequencing

BackgroundThe incidence of prostate cancer in China has increased rapidly in recent years,with more than half of the patients diagnosed with advanced tumors,which increases the difficulty of clinical treatment.Androgen deprivation therapy(ADT),as the cornerstone of the treatment of advanced prostate adenocarcinoma(ADPC),is gradually getting into trouble.Almost all patients will eventually progress to castration-resistant prostate cancer(CRPC)after approximately one year of ADT,with a declining prognosis and quality of life.Some recurrent tumors are different from the original adenocarcinoma,having the characteristics of neuroendocrine differentiation(NED).As the new generation of androgen receptor pathway inhibitors more powerfully inhibits the androgen receptor(AR)pathway,the incidence of NED in prostate cancer also increases,evading existing treatments with a mechanism that does not rely on the AR pathway.At present,the understanding of NED in prostate cancer is still insufficient,making it a challenge to develop effective targeted therapies.Therefore,in-depth research on the characteristics and mechanism of this type of disease is on demand.MethodsThe rapid development of single-cell sequencing technology in recent years has made it possible to study the heterogeneity within tumors at the single-cell level.In this project,a total of 4 cases of neuroendocrine carcinoma of the prostate(NEPC)samples were collected,and single-cell transcriptome sequencing was performed.Further bioinformatics analysis was performed jointly with the published public single-cell sequencing data of 3cases of NEPC.We explored the cell components,clonal heterogeneity,neuroendocrine expression program,and the process of cloning evolution from ADPC to NEPC.ResultA total of 36,036 cells were included in the analysis,from which 19,605 malignant cells were identified based on transcriptome similarity and large-scale copy number variation.Except for the shared deletion of chromosome 13,gnomes of tumor cells showed pronounced heterogeneity among samples and within-sample poly-clonality.Analysis of gene expression programs in different samples identified ten modules with coherent expression across samples,two of which are related to NED,including a differentiation-related module(including ASCL1,NKX2-2,PROX1,and other transcription factors)and one function-related module(including CHGA,CHGB,SCG2,and other functional genes).The simultaneous activity of the two modules was observed in two of the seven samples.Preliminary evidence suggests that the two modules may respectively represent the early and late stages of the NED process.In the end,we formulated a clone evolution model depicting the "ADPC→NEPC" process based on the cloning and phenotype information of the tumor.ConclusionThis project applied single-cell transcriptome analysis to analyze the different cellular components within the tumor entity.Malignant cells were identified based on genomic alterations.The change of genome-wide copy number suggests that ADPC and NEPC share the same cloning origin,supporting the transdifferentiation theory.We identified two distinct expression modules representing NED at various time points through multi-sample integration analysis,which improved our understanding of NEPC’s heterogeneity.The clone evolution analysis observed the independent NED process in different clones within a single sample.This observation helped improved the model depicting the "ADPC→NEPC" process.