Balb / C Nude Mice With Human Colon Cancer Animal Model To Establish And Model Of Tumor Ki67 Protein Expression

Background:Colorectal cancer is a malignant tumor of the gastrointestinal trac t common in recent years, Its morbidity and mortality of China's largest city is on the rise. Experimental animal models of human tumor replication studies u sing animal models can reduce the time to observe the tumor genesis and deve lopment of the whole process can be carried out under controlled conditions in human experiments research on the mechanism of tumor development, preventi on and treatment of great significance.Objective:1 Establishment of human colon cancer in nude mice animal model for the treatment of colorectal cancer and provide a reliable animal model.2 Use of nude mice model of human colon tumor specimens of an imals make for research of Ki67 protein.Methods:1 Test animal and cell:BALB/C mice, weighing 20～25g, were males, Beijing Vital purchased in China. HCT-8 human colon cancer cells, hu man colon cancer cell line LS-174-T, human colon cancer cell line SW620, we re purchased from Shanghai Institutes for Biological Sciences Chinese Academy of Sciences.2 Test animal feeding:BALB/c nude mice, mice aged 4 weeks, then group, n= 10, a total of 3 groups, with three kinds of cancer, the correspon ding strains. Keeping the environment constant temperature and humidity, clean, non-specific pathogens, periodic replacement of bedding, clean drinking water and feed intake for the mouse free.3 Human colon cell culture:containing 10% fetal bovine serum,100 U/mL blue, streptomycin, RPMI-1640 medium plus 0.2% NaHCO₃ adjusted pH 7.0～7.2, placed in the incubator with 5% CO₂ at 37℃, with 0.25% trypsin and passaged.4 Construction for model of tumor cells:in logarithmic growth pha se in order to configure the PBS solution were inoculated into cell suspension. Inoculation cell concentration of 1×10⁷/ml, each nude mouse inoculation 0.2ml. Strong iodine disinfection of the left flank of nude mice, with the scale for t he lml syringe extraction configured cancer 0.2ml, the total number of cells in 2×10⁶/ml, injected into the left flank of nude mice. Three kinds of cancer lin es were injected into 3 groups corresponding to nude mice.5 Growth of inoculated mice:First week, nude activities, as usual, e ating normal, no change in shape; Second weeks, most of the nude, the naked eye can see, there was a subcutaneous tumor nodules larger bean left flank el evated significantly; Third weeks, after the emergence of individual body weigh t loss in nude mice, action gradually slow to reduce food intake. Significant w eight loss;After Forth weeks, in nude mice, slow, poor spirit, slow tumor grow th, a stable platform; Seventh to Earth weeks,in nude anorexia, weak, nodule s appear ulceration, central necrotic area.6 Observation of tumor growth curves:in nude mice after inoculati on of tumor growth observed periodically test and its general situation and gra sp the time of tumor formation and growth observed in nude mice and nutritio nal status, and general activities. Long-term observation of thirty tumor-bearing mice inoculated with local palpable nodules, the record Incubation period:eve ry two days with a caliper measurement of tumor diameter and short diameter, into the next generation of calculated tumor volume:V= long diameter (mm)×short Path ² (mm²)/2.7 Anatomical and pathological observations:To be very frail nude mice were killed when the neck off routine dissection of animals derived. Subc utaneous tumor in 10% neutral formaldehyde, dehydrated, transparent, embedded in paraffin, sliced, HE staining and Fengpian observed under light microscope, camera.Results:1 Successfully established animal model, three kinds of cancer lines(L S-174-T, SW620, HCT-8) in tumor formation rates were 70%,80%,60%.2 S-curve of tumor growth showing growth of the tumor showed four stages:Stage 1 for the incubation period (1～7d); stage 2 for the slow growth period (8～14d); the first 3 stages of exponential growth phase (15～31d); Stage 4 for the growth and stability of (32～57d), due to tumor growth has reached a certain size and time, growth slowed down.3 HE biopsy revealed cells arranged in irregularly shaped glands with mitotic figures, and colorectal cancer tumor samples are consistent.4 Three nude mice animal model of human colon tumor specimens' positive expression rate of Ki67 protein is approximate; they are about 85% an d swelling consistent with colorectal cancer specimens.Conclusion:1 Cancer transplanted animal strains can establish a good animal model, which laid the foundation for further study for colon cancer.2 Three nude mice animal model of human colon tumor specimen s'positive expression rate of Ki67 protein is approximate; they are about 85% and swelling consistent with colorectal cancer specimens.3 Nude mice animal model of human colon cancer tumor samples can replace the clinical specimens of colorectal tumor Ki67 protein.