Construction Of Phage Antibody Library For Bladder Cancer And Study Of Microbial Composition

Bladder cancer is a malignant tumor with 573,000 new cases worldwide in 2020,of which the incidence in men is 5 times higher than that in women.The main clinical diagnostic modality for bladder cancer at this stage is cystoscopy,and the main treatment modality is surgical treatment to remove the tumor,but more than 50%of patients will recur,and the survival rate is even only 25%within 5 years.Therefore,more and more researchers are working to develop new and effective diagnostic and therapeutic strategies for bladder cancer.Monoclonal antibodies（m Ab）play an important role in the diagnosis and treatment of tumors.With the advent of phage antibody library technology（PALT）,scientists are working on the application of PLAT for the development of third-generation antibodies,since m Ab produced by PALT are fully human and do not elicit an immune response in the body.In addition to this,studies have found a strong link between cancer and specific microbial factors,with up to 20%of human malignancies being caused by microbes.Bacterial 16Sr RNA is characterized by its characteristic evolutionary sequence,conserved gene sequence and universality,making 16Sr RNA technology an important tool for microbial composition detection and taxonomic identification.In summary,this study aimed to develop novel treatment methods for bladder cancer by constructing a bladder cancer phage antibody library and identifying the microbial composition specific to bladder cancer.The absolute library capacity was 10⁷for VH-VLκand 10⁹for VH-VLλ.The difference between VH-VLκand VH-VLλwas large and the library capacity was not high,while the absolute library capacity was 10¹⁰for VH-VLκ/λin the mixed library.The results showed that the hybrid library is more operable and has a larger library capacity than the single library,which can be a solid foundation for the next step to better screen for the specific all-human m Ab for the treatment of bladder cancer.We used 16Sr RNA sequencing technology to resolve the microflora structure of 7 cancer tissues and 6 paracancer tissues of bladder cancer,extracted genomic DNA from 13 samples,and performed uniform Nova Seq up-computing to find 802 operation taxonomy units specific to the cancer tissues.The analysis of cancer tissues and paracancerous tissues revealed a total of six groups of bacteria that could act as landmarks of cancer tissues and paracancerous tissues,including Oceanospirillales,Halomonadaceae,Corynebacteriales,Nocardiaceae,Rhodococcus,Dietziaceae.It was demonstrated that this approach can be used to identify the microbial composition that can specifically distinguish bladder cancer and in combination with other indicators can be useful for the diagnosis of bladder cancer.The extraction of microbial genomic DNA from urine was also investigated,laying the groundwork for future high-volume experiments comparing urine from bladder cancer patients and normal subjects.