动物造模,药效评价,转基因宫颈癌 z-bio 2024-08-01 506

　　[Modeling mechanism] Currently, over 200 subtypes of HPV have been identified, of which about 40 subtypes can infect the reproductive tract and be transmitted through sexual contact. HPV infection is directly related to the occurrence of cervical cancer. High risk HPV can integrate with host chromosomes and is the most direct initiating factor for early cervical cancer/precancerous lesions. The HPV16, 18 E6, and E7 genes have been confirmed to be transforming genes, and their encoded E6 and E7 proteins are continuously expressed in cervical cancer cell lines and cancer tissue cells, playing a crucial role in maintaining the malignant phenotype of transformed tissues. The E6 and E7 proteins of HPV virus can interact with p53 and Rb, among which E6 protein binds to p53 through the cell ubiquitin ligase E6AP, leading to the degradation of the tumor suppressor gene p53, disrupting the P14-DM2-p53 pathway mediated by p53, losing normal regulation and causing infinite cell proliferation; E7 protein competes to preferentially bind to pRb, causing pRb to dissociate from E2F and increasing free E2F, leading to dysregulation of the P16 cyclinD CDK4/6-pRb E2F pathway, initiating G1-S phase progression, and causing infinite cell proliferation.

　　[Modeling Method] The HPV16E6/7 gene was extracted from human cervical cancer tissue, and the pCEP4 vector was used as the backbone to initiate downstream gene expression using the human cytomegalovirus promoter. A DNA portion containing a linearized human cytomegalovirus promoter, an HPV16E6/7 target gene, and an SV40PolyA tail was obtained by microinjection of exogenous genes into the male pronuclei of fertilized eggs from donor mice, followed by implantation into the fallopian tubes of pseudopregnant recipient mice, resulting in stable inheritance of HPV16E6/7 transgenic mice.

　　The establishment of HPV16 transgenic mice began in the 1990s. In 1994, Arbeit et al. used the K14 promoter to create transgenic mice for HPV16 progressive squamous cell carcinoma. That same year, Sasagawa et al. created transgenic mice for HPV16 E6/7 cervical and vaginal atypical hyperplasia. In 1996, Herber et al. used the HPV16E7 oncogene to create transgenic mice for squamous cell carcinoma. In 2000, Shiyu Song et al. used the IHIN promoter to create transgenic mice expressing HPV16 E6 and E7 proteins.

　　【 Model Characteristics 】 The model mice begin to show atypical skin hyperplasia at around 4-6 months, and almost all mice die from malignant tumors such as cervical cancer, skin cancer, eye cancer, and rhabdomyosarcoma at around 18 months.

　　Model evaluation and application: HPV transgenic mice mainly use skin specific promoters to initiate downstream gene expression, so the obtained tumor model is mainly composed of squamous epithelial tumors; If the CMV promoter used is a universal promoter, it can exhibit strong activity in most cells and tissues, resulting in tumors of various tissue origins. The established HPV transgenic model mice have a longer survival time, which allows for sufficient time to obtain a sufficient number of mice for in-depth research on their carcinogenic mechanisms, and also facilitates the promotion and application of the model mice. The establishment of HPV16E6/7 transgenic mouse pathological model by microinjection technology will provide an animal model system for further research on the carcinogenicity of HPV and the interaction between HPV and the body, research on HPV infection related diseases, treatment of skin cancer and cervical cancer, and evaluation of HPV vaccine, and will have potential application value in preventing HPV infectious diseases in China.

　　With the widespread application of genetic modification, gene knockout and other technologies in experimental animal models, the variety and strains of experimental animals, as well as the types of animal models with human disease characteristics, have also grown rapidly. Establishing an ideal cervical cancer animal model will play a key role in further understanding the pathogenesis of cervical cancer and effectively preventing and treating it.