The Expression And Significance Of RSK4 In The Development Of Oral Squamous Cell Carcinoma

ObjectiveRibosome S6 protein kinase 4(RSK4)is one of the members of the ribosome S6 protein kinase gene family.Its molecular weight is 90 k Da,located in human Xq21.It is an important downstream regulator of MAPK/ERK kinase pathway and important signal transduction in Ras pathway molecular.The study found that it could participate in cell cycle regulation and regulation of gene transcription and thus affect cell proliferation,differentiation and apoptosis.Scholars at home and abroad found that RSK4 was abnormally expressed in breast cancer,leukemia,colorectal cancer,renal cell carcinoma,pancreatic cancer,endometrial cancer,ovarian cancer,etc,and played a role of tumor suppressor gene in large number of tumors.That suggested it was related to the occurrence and development of malignant tumors.So far,there has not been report about the correlational research between RSK4 and oral squamous cell carcinoma(OSCC)at home and abroad.In this study we will detect the expression of RSK4 in normal oral mucosa,abnormal hyperplasia and OSCC groups,and To explore the expression and significance in the occurrence and development of OSCC.Method1.The method of real time quantitative PCR was used to detect the expression of RSK4 m RNA in normal oral mucosa,abnormal hyperplasia and OSCC groups.2.The immunohistochemical method was used to detect the expression of RSK4 protein in normal oral mucosa,,abnormal hyperplasia and OSCC groups,and we also analyze the relationship between RSK4 protein and histopathological parameters such as sex,age,clinical stage,lymph node metastasis and pathological grade in OSCC group.Results1.The average relative expression of RSK4 m RNA in normal oral mucosa,abnormal hyperplasia and OSCC group was 1.077 ± 0.41,0.784 ± 0.31 and 0.221 ± 0.19.The relative expression of RSK4 m RNA in OSCC was lower than that in normal oral mucosa group,and the difference was statistically significant(P <0.01).The relative expression of RSK4 m RNA in abnormal hyperplasia was lower than that in normal oral mucosa group,and the difference was statistically significant(P <0.05).The relative expression of RSK4 m RNA in OSCC was lower than that in abnormal hyperplasia group,and the difference was statistically significant(P <0.01).2.The positive expression of RSK4 protein was brown,and its expression was mainly located in the cytoplasm and membrane of the cell,and the small part was located in the nucleus.3.The positive rate of RSK4 protein expression in normal mucosa group was 100%,The positive rate of RSK4 protein expression in abnormal hyperplasia group was 73.3%,and the positive rate was 43.6% in OSCC group.The positive rate of RSK4 protein expression in OSCC group was lower than that in normal oral mucosa group,the difference was statistically significant(P <0.01);abnormal hyperplasia group was lower than that of normal oral mucosa group,the difference was statistically significant(P<0.05);OSCC group was lower than that in abnormal hyperplasia group,the difference was statistically significant(P<0.05).4.In the OSCC group,the positive rate of RSK4 protein expression in stage III ~ IV(21.4%)was lower than that in stage I~ II(52.9%),and the difference was statistically significant(P <0.05);The positive rate of RSK4 protein expression with lymph node metastasis(10%)was lower than that of non lymph node metastases(52.6%),and the difference was statistically significant(P <0.05);the positive rate of RSK4 protein expression in well differentiated squamous cell carcinoma was 58.3%,the positive rate of moderately differentiated squaous cell carcinoma was 38.5%,and the positive rate of poorly differentiated squamous cell carcinoma was 9.1%,the difference was statistically significant(P <0.05);The positive rate of RSK4 protei expression with different genders and different ages were no statistically significant difference(P >0.05).Conclusion1.The RSK4 gene may be involved in the occurrence and development of OSCC and play a role as the cancer suppressor gene.2.RSK4 plays a role in the early stage of OSCC,and RSK4 detection may reflect the state of precancerous lesions in oral mucosa,thus screening patients with early signs of malignancy.3.The expression of RSK4 protein is related to clinical stages,lymph node metastases,pathological gradation.We hypothesized that RSK4 may be a valuable molecular marker in the development of OSCC.It can be considered as one of the biomarkers for evaluating the prognosis and guiding treatment.