Gene Biomarkers For The Diagnosis Of Metastatic Prostate Cancer Based On Circulating Tumor Cells

Prostate cancer(PCa)is the most common malignant tumor of the genitourinary system in males,accounting for the fifth largest number of cancers in the world.The incidence of prostate cancer in Western countries is even the highest among male malignant tumors [1].In recent years,the incidence of prostate cancer in China has shown a significant upward trend.It is expected that by 2020,the incidence of prostate cancer in China will exceed 40/100,000 men,close to the level of Europe and the United States,and become the main cancer killer that endangers men's health [2].According to statistics,the 5-year survival rate of localized PCa patients is almost100%,and the 5-year survival rate of PCa patients with distant metastases has dropped to approximately 29% [3].Therefore,reducing the proportion of patients with metastatic prostate cancer at the time of initial diagnosis and accurate diagnosis of potential metastases will be crucial to improve patient survival.ObjectiveTargeting patients with metastatic prostate cancer in China to investigate prostate cancer-related gene markers based on circulating tumor cells(CTCs),addressing the major clinical needs of early diagnosis,treatment assessment and personalized treatment of prostate cancer,and improving prostate cancer patients in China The overall 5-year survival rate provides a scientific basis for the development of prostate cancer diagnostic kits with independent intellectual property rights.MethodsThrough bioinformatics comparison and analysis,14 candidate genes with high specific expression associated with metastatic prostate cancer were obtained,and prostate cancer cell lines(PC3,VCaP,LNCaP)were used.Human blood and patient clinical samples were verified by fluorescence quantitative PCR,and genes that were expressed in the normal human blood in candidate genes were excluded.Finally,five prostate cancer-specific marker genes with clinical test application prospects were obtained: KLK2,KLK3,FOXA1,GRHL2 and HOXB13.Real-time quantitative reverse transcription-polymerase chain reaction(RT-qPCR)technology was used todetect the expression of five genes in human prostate cancer cells(LNCap),and a combined detection method for multiple gene expression was established.Blood samples from metastatic prostate cancer patients and healthy volunteers were collected and blood samples and human prostate cancer cells were assessed for consistency,repeatability,linearity,and sensitivity.By comparing the CTCs counts and gene expression results in patients' blood samples,the significance of prostate cancer-related marker gene expression levels for the prognosis of patients was determined.ResultsThe five genes of FOXA1,HOXB13,KLK2,KLK3,and GRHL2 can be used as fluorescent quantitative RT-PCR method to detect prostate cancer in circulating tumor cells in peripheral blood;The results showed that there was a consistent linear relationship between the expression levels of five genes and the logarithm of different dilutions of LNCap RNA:KLK2(0.995)?KLK3(1)?FOXA1(0.992)?GRHL2(0.999)?HOXB13(1);The range of five gene tests are KLK2(5 pg-1?g)?KLK3(1 pg-1?g)?FOXA1(10 pg-1?g)?GRHL2(100 pg-1?g)?HOXB13(100 pg-1?g);CTCs count and multiple gene expressions showed correlations;The higher the CTCs count in a patient,the higher the positive rate of multiple gene expressions detected.ConclusionThe five genes: FOXA1,HOXB13,KLK2,KLK3,and GRHL2,can be used as marker gene for the detection of prostate cancer in circulating tumor cells in peripheral blood by fluorescence quantitative RT-PCR.The combined detection of KLK2,KLK3,FOXA1,GRHL2 and HOXB13 gene has the advantages of simple and more convenient operation,better accuracy and sensitivity,and provides new ideas for further development of clinical prognosis of prostate cancer.