Application Of PTC028 In Head And Neck Squamous Cell Carcinoma And PDX Model

Objective:The effect of PTC028 in head and neck squamous cell carcinoma(HNSCC)was studied in vitro and in vivo.Patient-derived xenograft(PDX)model of HNSCC was established.After that,the application of PTC028 combined with cisplatin in PDX model of HNSCC was further studied to explore a new clinical treatment for patients.Methods:1.Effects of PTC028 on biological behavior of HNSCC:After treatment with PTC028,the change of BMI1 protein expression in HNSCC lines was detected by Western Blot.CCK-8 was used to detect the effects of different concentrations of PTC028 on cell proliferation.Scratch test was used to observe its effect on cell migration.Transwell test was used to detect the change of cell invasion.TUNEL method was used to analyze apoptosis.The effect of PTC028 on transplanted tumor was investigated by constructing subcutaneous tumor transplantation model in nude mice.2.Establishment and identification of PDX model of HNSCC:Human tumor tissues within 30 minutes in vitro were placed into mice with severe immune deficiency under aseptic conditions,and sequence passage was performed when the volume of transplanted tumor increased to 800-1000mm~3.Part of the transplanted tumor was retained in each passage,which was used for subsequent identification of whether the transplanted tumor was consistent with the primary tumor in terms of histopathological,molecular and genomic characteristics.The identification methods included H-E staining,immunohistochemical staining and whole exome sequencing.3.Application of PTC028combined with cisplatin in PDX model of HNSCC:The successfully constructed PDX model mice were randomly divided into 4 groups,namely control,cisplatin,PTC028 and cisplatin+PTC028 group.Each group was given corresponding drugs,and the changes of vital signs and transplanted tumors of mice were observed.After 4 weeks administration,the transplanted tumors were collected and their volume and mass were measured.Then,we were collected the heart,liver,spleen,lung and kidney of mice in each group for H-E staining to observe whether PTC028 had drug toxicity in mice.4.Statistical analysis:Independent sample t-test was used to analyze the significance between two groups of samples.WhenP<0.05,there was considered statistically significant.Results:1.PTC028 could significantly inhibit the expression of BMI1 protein in HNSCC,inhibit the proliferation,migration and invasion,promote cell apoptosis,and inhibit the growth of nude mice transplanted tumors.2.In this study,PDX models of primary tumors in 7cases of HNSCC were successfully constructed and sequentially passed for more 3generations.The results of H-E staining,immunohistochemical staining and whole exome sequencing indicated that the transplanted tumor was highly consistent with the primary tumor at the histopathological,molecular and genomic characteristics.3.The results of combined administration suggested that the growth rate of transplanted tumors and mass in the administration group was lower than that in the control group.The growth rate of tumor volume in the combination of the two drugs was the slowest,and no obvious drug toxic reaction occurred in vivo.Conclusions:1.PTC028 can significantly inhibit the expression of BMI1 protein in HNSCC,and inhibit the occurrence and development of HNSCC.2.The PDX model of HNSCC retains the histopathological,molecular and genomic characteristics of the primary tumor.3.PTC028 combined with cisplatin has a synergistic effect in the treatment of HNSCC,and is well tolerated in vivo,suggesting that PTC028 combined with cisplatin is expected to be a new clinical treatment for patients with HNSCC.