动物造模,药效评价,诱发性鼻咽癌 z-bio 2024-07-16 490

　　The induced nasopharyngeal carcinoma model is mainly a nasopharyngeal carcinoma animal model formed by the action of chemical carcinogens on animals.

　　[Modeling mechanism] Nasopharyngeal cancer has a high incidence rate and unknown causes. Environmental factors (exposure to chemicals) are currently recognized as one of the pathogenic factors. Long term exposure to chemical drugs in animals can induce nasopharyngeal epithelial cell carcinogenesis and nasopharyngeal carcinoma.

　　[Method of Modeling]

　　1. Dimethyl cholanthracene intubation method is used to select rats weighing around 120g, both male and female. After ether anesthesia, a specially designed hard plastic tube containing MC is inserted into the nasal cavity through the anterior nostril. The hard plastic tube has a diameter of 2-3mm and a length of about 3.5cm. It is pulled into a cone shape on an alcohol lamp and filled with crystalline MC. One end is sealed with fire to prevent drug leakage, and the tip is punctured several times to allow MC to overflow from the small hole. When inserting the tube, taking advantage of the small size of the rat's anterior nostril and the small diameter of the tube, a little force is applied to force the small tube to completely enter the nasal cavity, and its tip can reach the nasopharyngeal cavity without the need for additional fixation, allowing the small tube to remain in the rat's nasal cavity for a long time.

　　2. The diethylnitrosamine (DEN) nasal drip method was used to select rats weighing around 120g, both male and female, and anesthetized with ether. Extract 0.02ml (containing 6.7mg of DENA) of 33.3% DENA suspension prepared with 1% Tween-80 using a syringe. Install an 8 # needle with a ground needle tip on the syringe and gently insert it into the rat's anterior nostril until the needle tip reaches the nasopharynx. Then, push the syringe to drop the DENA suspension into the rat's nasal cavity. Drip once a week for 15-20 weeks.

　　3. Dinitropiperazine (DNP) subcutaneous injection method: Select rats weighing 100-150g or 18-20g naked mice, and use a syringe to extract a 0.5% DNP aqueous solution [15mg/(kg · time)] for subcutaneous injection into the back or axilla twice a week. Continuous injection for more than 6 months.

　　【 Model features 】 ① MC intubation method: When a specially designed tube containing MC crystals stays in the nasal cavity of rats for more than 6 months or when the animal naturally dies, pathological sections are taken from the nasopharyngeal tissue, and the cancer incidence rate can reach over 60%. ② DENA nasal drip method: After stopping the medication, continue to observe for more than 6 months or when the animal naturally dies, take its nasopharyngeal tissue for pathological section DNP subcutaneous injection method: After 6 months of subcutaneous injection, animals can develop nasopharyngeal carcinoma. As the survival time of animals prolongs, the proportion of cancerous changes increases, reaching over 85%. During the dynamic changes of nasopharyngeal epithelial lesions at different stages of carcinogenesis, atypical proliferation of basal cells, squamous epithelial cells, and columnar epithelial cells is highly positively correlated with cancer progression.

　　【 Model Evaluation and Application 】 There are many triggering factors for nasopharyngeal carcinoma, so there are also various methods to construct nasopharyngeal carcinoma animal models. By inducing the occurrence of nasopharyngeal carcinoma through a single factor, the biological characteristics of nasopharyngeal carcinoma can be effectively studied, and it can be used for screening related drugs, making it an effective means of studying nasopharyngeal carcinoma. In addition, the synergistic effect of EB virus and oncogenes in inducing a human nasopharyngeal malignant tumor model can be used for the study of the etiology and mechanism of nasopharyngeal carcinoma. But the induced tumor pathology is malignant lymphoma and undifferentiated carcinoma, which is different from highly differentiated squamous cell carcinoma of human nasopharyngeal carcinoma. The success rate of induced nasopharyngeal carcinoma model is high, but the required time is long, which greatly limits the experimental process.