PRSS21 Mediates Inhibition Of MYCT1 In The Proliferation And Migration Of Laryngeal Carcinoma Cells

Introduction: Laryngeal carcinoma is one of the most common otolaryngological malignant tumors.In China,laryngeal carcinoma accounts for about 13.9% of head and neck tumors.The incidence of laryngeal carcinoma is still rising in recent years,with a high incidence in northeast and north China.The age of laryngeal carcinoma patients ranges mainly from 40 to 60 years old and the incidence in males is higher than that in females.Many studies have shown that laryngeal carcinoma is related to smoking,drinking,sex hormone levels,human papillomavirus infection,air pollution,occupational factors and other factors,among which smoking and drinking are the main risk factors.Although the research on laryngeal carcinoma has made a great progress,the molecular mechanism and development of laryngeal carcinoma occurrence are still indistinct.Therefore,it is particularly important for us to study the pathogenesis of laryngeal carcinoma from the molecular level,which will provide us clues for diagnosis and treatment of laryngeal carcinoma.The MYCT1 gene(myc target 1)plays oncogenic or tumor suppressive roles in different tumors,suggesting that it has tissue specificity and may be involved in the occurrence and development of tumors through different signal transduction pathways.Studies have shown that MYCT1 inhibited laryngeal carcinoma cell proliferation and migration and promotes laryngeal cancer cell apoptosis.MYCT1 plays a potential tumor suppressor role in laryngeal carcinoma.However,the mechanism of MYCT1 in laryngeal carcinoma is still indistinct.The PRSS21 gene(serine protease 21)encodes testosterone,which is normally expressed in testicular germ cells,but is expressed lowly or absent in other normal tissues.Studies have displayed that PRSS21 was silent in testicular tumors of stem cells origin,but highly expressed in other tumors including ovarian,cervical,gastric melanoma and lymphoma.PRSS21 has been reported to be closely related to the occurrence,invasion and metastasis of some tumors and play an important role in tumors.Nevertheless,PRSS21 expression and mechanism in laryngeal carcinoma and other tumors are still unclear and need to be further studied.In our previous study,we found a series of differentially expressed proteins in laryngeal carcinoma cells with MYCT1 stable-overexpression through i TRAQ technology,in which the PRSS21 gene was decreased at protein level.It suggested that the PRSS21 gene was associated with the MYCT1 gene and might participate in laryngeal carcinoma genesis and development as a mediator of MYCT1.In the study,we intend to use molecular biological techniques to detect the expression and biological function of the PRSS21 gene in laryngeal carcinoma and explore the role of MYCT1 in laryngeal carcinoma via the PRSS21 gene.Materials and methods: 1.Materials and reagents: human laryngeal carcinoma cell line(Hep-2 cells),human oral keratinocyte cell line(HOK cells),44 pairs of laryngeal carcinoma tissue and paracancer tissue samples.2.Methods: cell culture,tissue processing,plasmid extraction,cell transfection,total RNA extraction,RT-PCR and real-time PCR,membrane protein and cytoplasmic protein extraction,Western Blot,CCK-8 cell proliferation assay,clone formation assay and scratch assay.Results: 1.The results of Real-time PCR and Western Blot displayed that PRSS21 was significantly overexpressed in laryngeal carcinoma tissues and cells compared to controls(P<0.05).2.The analysis results of clinical characteristics showed that the expression of PRSS21 was closely related to the T stage,lymph node metastasis and TNM stage of laryngeal carcinoma(P<0.05).3.CCK-8 cell proliferation assay,clone formation assay and scratch assay indicated that PRSS21-si RNA significantly inhibited the proliferation and migration of laryngeal carcinoma cells(P<0.05).4.The results of Real-time PCR and Western Blot displayed that MYCT1 significantly inhibited the expression of PRSS21 both at m RNA and protein levels in laryngeal carcinoma cells(P<0.05).5.CCK-8 cell proliferation assay,clone formation assay and scratch assay demonstrated that MYCT1-si RNA promoted the proliferation and migration of laryngeal carcinoma cells(P<0.05),respectively,and PRSS21-si RNA significantly rescued the effect of MYCT1-si RNA on the proliferation and migration of laryngeal carcinoma cells(P<0.05).Conclusion: 1.PRSS21 is upregulated in laryngeal carcinoma,suggesting it plays an oncogenic role in laryngeal carcinoma.2.The expression of PRSS21 is closely related to the T stage,lymph node metastasis and TNM stage of laryngeal carcinoma.3.PRSS21 promotes proliferation and migration of laryngeal carcinoma cells.4.MYCT1 inhibits the expression of PRSS21 in laryngeal carcinoma.5.PRSS21 mediates inhibition of MYCT1 in the proliferation and migration of laryngeal carcinoma cells.