【Animal Modeling】-Animal Model of Endometrial Cancer

  Endometrial carcinoma (endometrial carcinoma), also known as uterine corpus cancer, originates from the endometrium epithelium. It is one of the three major malignant tumors of the female reproductive tract, accounting for about 7% of the total number of female cancers and 20% of the total female reproductive tract malignancies. % To 30%, the incidence has a significant upward trend. The age of onset is getting younger, and the proportion of patients younger than 40 years old has increased from 1% to 8% in the past to 13.3%. Endometrial cancer is an important cause of perimenopausal bleeding in women. It is easy to be misdiagnosed as irregular menstruation and delayed diagnosis. Its etiology is not clear so far, but it is mainly related to the long-term stimulation of estrogen. The animals used to replicate endometrial cancer are mainly immunodeficient mice, and a few use nude rats.

  【Modeling mechanism】

  1. Human endometrial cancer cells were injected subcutaneously or uterine cavity in nude mice to establish subcutaneous tumors and tumors in situ respectively. Green fluorescent protein can be used to label cells and observe the lymph node metastasis of tumor cells in vivo.

  2. The surgically resected specimens of human primary endometrial cancer were transplanted into nude mice to establish animal models.

  【Modeling method】

  1. Mouse

  (1) Choose 4 to 5 weeks old BALB/c-nu/nu nude mice, female, weighing 10-12g. The human endometrial cancer cell line (Ishikawa cell line, HEC-1A or HEC-1B cell line), the logarithmic growth phase cells were used for the experiment.

  (2) Model preparation: Digest and collect human endometrial cancer cells, centrifuge at 800r/min for 5-8 minutes, discard the supernatant, and dilute the cells according to the inoculation concentration of 5×10000000/0.1ml. Disinfect the skin of the left lower limb of nude mice near the groin. After inoculation, observe whether there is ulceration and redness at the injection point every day. The standard for tumor formation is that the diameter of subcutaneous nodules exceeds 0.5 cm. The tumor will form in about 2 weeks. When the tumor grows to 1 cubic centimeter, the tumor tissue is taken out and placed in a culture medium containing 10% fetal bovine serum. The tissue block was cut into 1.5mm×1.5mm×3mm tumor masses, and subcutaneous inoculation was carried out with a small incision and a sterile trocar. The small incision was sutured with a needle. Placed in an independent ventilated cage sterilized at a constant temperature to observe the tumor formation of nude mice. The tumor size was measured with vernier calipers every 3 days until 45 days after inoculation, and pathological examinations were performed.

  (3) Model test: ①Determination of tumor growth curve in vivo: Measure the body weight and tumor volume of nude mice, and measure the length (L), width (W) and height (H) of the tumor with a vernier caliper. The tumor volume (V) is according to the formula Calculation: V=Л/6(L×W×H), the unit is centimeter (cm). Some tumor tissues were fixed with 10% formaldehyde, and some tumor tissues were stored in liquid nitrogen for later use. ② Pathological examination of the transplanted tumor: After the nude mice bearing the tumor were sacrificed, the morphology of the transplanted tumor was observed, and fresh tumor tissues were taken for histological determination and immunohistochemical detection of common oncogenes. ③ DNA ploidy detection of transplanted tumor: A fresh tumor tissue piece, about 5mm in diameter, was rubbed slightly on a 200-mesh copper net to prepare a single-cell suspension, measured by flow cytometry, and detected by uterine cancer cell lines The result serves as a control. ④Immunohistochemical detection of oncogene: the detection result of uterine cancer cell line serves as a control.

  2. Rats Choose nude rats. After the frozen Ishikawa cells were resuscitated, they were cultured to the logarithmic growth phase, and a skin mound was made under the loose skin near the ventral side of the hind limbs of nude rats, containing 0.5ml cell suspension (1×1,000,000 cells). After 2 weeks, the tumor was trimmed into 2 cubic millimeter tumor masses, placed in a petri dish filled with isotonic saline and placed on ice for later use. After the nude rat is anesthetized, make a 2cm incision in the middle of its lower abdomen to expose the bilateral uterus, cut the entire anterior wall of the upper 1/3 of the left uterus, and implant the tumor mass into the uterine cavity with micro forceps .

  [Characteristics of the model] The tumor-bearing nude mice were significantly thinner in the late stage, with decreased mobility and responsiveness, and cachexia until exhaustion and death. From the growth curve of the second-generation transplanted tumor inoculated with subcutaneous tumor tissue block, it can be seen that the tumor's swelling growth can be observed in a short period of time. The subcutaneous tumor in the primary cell fluid grows fast. When the subcutaneous tumors of nude rats are grown for 2 weeks, orthotopic transplantation of young nude rats is performed, and the tumor formation rate can reach 70%.

  【Model Evaluation and Application】By establishing a mouse subcutaneous transplantation tumor model of human endometrial cancer cell lines, it simulates the growth environment of human endometrial cancer and conforms to the biological characteristics of human endometrial cancer. It can be used as a suitable animal model for exploring the treatment and biological treatment of human endometrial cancer with traditional Chinese medicine and objectively evaluating the effects of treatment methods. 3 to 4 weeks after orthotopic transplantation of nude rats, the tumor growth is limited to the uterus, and the tumor can be detected by naked eyes without metastasis. This is just in line with the clinical characteristics of human early endometrial cancer. Nude rats are larger in size, organs, blood vessels, etc. than nude mice, and are more suitable for complex operations in in vivo experimental research. Especially their pelvic blood vessels are larger and can be used for experimental research on human tumor interventional therapy.