The Significance Of ELAM-1 In Metastasis Of Nude Mouse Transplanted Nasopharyngeal Carcinoma

Objective: To investigate the expression of ELAM-1 in nude mouse nasopharyngeal carcinoma implants and metastases,including lymph node metastases and distant metastases,and to further confirm that ELAM-1 is an important molecular market for nasopharyngeal carcinoma metastasis.Methods: 1)In cell culture,nasopharyngeal carcinoma Cell Strain SUNE1-sub-strain 5-8F cells were cultured in a complete culture medium which made from 1640 medium,fetal bovine serum,and green streptomycin in a37°C,5% CO2,constant temperature incubator.Observing the state of cell growth every day.Replacing the culture solution in time and performing subculture.Freezing the excess cells at the appropriate time.The cells were cultured in 6-well plated for 0 h,24 h,48 h,72 h,96 h,120 h,and 144 h,and the number of cells at each time point was counted to drawing the cell growth curve.2)Each 16 female nude mice were weighed before transplanting the cancer cells,then,injected 20?L of a nasopharyngeal carcinoma cell suspension in logarithmic growth(the tumor cells were approximately 2×106)on the left hind paw pad.Observing the growth of nude mice daily,routinely anesthetize for 8 weeks after inoculation,and kill all nude mice.Performing detailed anatomical examination,measuring the size of the tumor,observing the tumor and metastasis.All specimens were fixed in formalin,paraffin-embedded,sectioned,HE stained and immunohistochemically stained.3)HE staining was used to observe each pathological tissue and determine whether there were metastases in each tissue.Nude mice were divided into metastatic group and non-metastatic group depend on whether there is metastatic cancer.4)Differences in initial body weight between nude mice in metastatic and non-metastatic groups were compared using analysis of variance.5)Immunohistochemistry was used to detect the expression of ELAM-1 in nude mice with nasopharyngeal carcinoma,lymph node metastases,and distant metastases.The expression of ELAM-1 in each group was quantitatively analyzed using IMAGE J software.Results: The cultured cells all grew well.16 nude mice had successful tumorigenesis,and the nude mice had normal vital signs and growth state was stable during the tumor-bearing period.All the tissues were fixed and embedded in formalin,and a total of 27 waxes and 81 slices were obtained after dissecting the nude mice.We successfully established a metastatic model of human nasopharyngeal carcinoma transplanted in nude mice.A total of 10 nude mice were metastasized to the metastasis group After HE staining,including seven lymph node metastases,one abdominal pelvic metastasis,two lymph node metastases and abdominal pelvic metastases.The other 6 patients had no metastases and they were non-metastatic.ELAM-1 expression was positive in all nude mice implanted with nasopharyngeal carcinoma,lymph node metastases,and distant metastases.Among them,the non-metastatic group had weakly positive tumors,and 4 cases were strongly positive and 6 were positive in the metastatic group.HE staining showed that the nuclei of cancer cells were dark blue and had a significant heterogeneity,and the cytoplasm and fibrous tissue were in shades of red.The normal lymph node tissue is round or oval,surrounded by a layer of pink capsules,the dark blue part underneath the capsule is the cortex,and the central light part is the medulla.Metastatic lymph nodes by HE staining showed that scattered nests of varying sizes can be seen in normal lymphoid tissues,with necrosis in some metastases.There was no significant difference in initial body weight between nude mice of metastasis group and non-metastatic group(P>0.05).The expression of ELAM-1 in the metastatic group was higher than that in the non-metastatic group,and the difference between the two groups was statistically significant(P<0.05).Conclusions: ELAM-1 is highly expressed in nasopharyngeal primary and metastatic carcinomas and is closely related to the metastasis of nasopharyngeal carcinoma.It is an important molecular marker for nasopharyngeal carcinoma metastasis.This provides ideas for the future development of targeted contrast agents and targeted drugs for the detection of early metastasis of nasopharyngeal carcinoma,which is expected to provide powerful help for clinical diagnosis and treatment of nasopharyngeal carcinoma.