Study Of The Expression And Clinical Significance Of CDK4 In Cutaneous Melanoma

Background and ObjectivesMelanoma is a malignant tumor derived from melanocytes.Melanoma may occur in any part of the body such as the skin,eyes and a few in the mucous membranes of the genitals,anus,mouth or other parts.Melanoma often metastasizes,often to regional lymph nodes,liver,lungs,and brain.The incidence of cutaneous melanoma has increased rapidly in recent years around the world.Traditional treatments for cutaneous melanoma include surgical resection,radiation therapy,and chemotherapy.Surgical resection is the key treatment for this disease,and it can cure the patients who have not metastasized.However,there are more and more patients with metastasis in clinical practice.Simple surgical resection can only improve the survival time.New treatment methods such as biological therapy,immunotherapy,and targeted therapy bring the gospel to patients with metastasis.The development of BRAF inhibitors has changed the clinical treatment of advanced melanoma and provides a more promising option for patients with advanced melanoma.Despite the short duration of response,patients treated with BRAF inhibitors have high ORR and often have significant tumor regression effects.In addition to the BRAF gene target,more new gene targets are currently under investigation.The protein encoded by the CDK4 gene is a member of the Ser/Thr protein kinase family.It is the catalytic subunit of the protein kinase complex and is important for the progression of the G1 phase of the cell cycle.Cyclin-dependent kinase 4 in cell cycle regulation(G1 to S conversion),complexed with cyclin D(D1,D2,D3),amplified in glioblastoma and anaplastic astrocytoma,amplified in diffuse large B-cell lymphoma;expanded and osteosarcoma of sporadic breast cancer,susceptible to familial melanoma by inducing abnormal repair of ultraviolet radiation.CDK4 plays a key role in the growth of tumors,and high expression of CDK4 can promote the indefinite growth of tumors.Studies have reported that CDK4 is highly expressed in a variety of cancers,but high expression of CDK4 in skin malignant melanoma has rarely been reported.With advances in gene and targeted therapies in recent years,research into the CDK4 gene in malignant tumors has gradually yielded results,and CDK4 inhibitors have been used for breast cancer,melanoma-targeted drugs such as BRAF inhibitors.CDK4 inhibitors are used in the development of cutaneous melanoma.We will treat patients with cutaneous melanoma in the First Affiliated Hospital of Zhengzhou University in recent years,analyze each patient’s condition,select the eligible patients for inclusion,exclude patients who do not meet,and then pass the immunization group.The method of CDK4 gene expression in melanin was compared with pigmented nevus to investigate the expression of CDK4 in melanoma.The expression of CDK4 was analyzed by analyzing the expression of CDK4 and tumor metastasis,survival,tumor stage and clinical manifestation.This can provide a theoretical basis for understanding the prognostic factors of skin melanoma and the pathogenesis of gene levels,and it will also promote the development of molecular targeted drugs.Methods1.The expression of CDK4 gene in 88 cases of pigmented nevus and 95 cases of cutaneous melanoma was detected by SP staining.2.Using the SPSS21.0 software,the expression of CDK4 in melanoma and pigmented nevus was statistically analyzed by chi-square test.3.Patients with melanoma were divided into high expression and low expression groups of CDK4.The K-M method was used for 5-year survival analysis,and then the survival rate was compared by log-rank method.4.The chi-square test was used to analyze the relationship between CDK4expression and clinicopathological features of cutaneous melanoma.(P<0.05 is considered statistically significant)Results1.The expression level of CDK4 in skin melanoma tissues was higher than that in skin nevus tissues,and the difference was statistically significant(P<0.05).The CDK4 expression was high in 71 cases and low in 24 cases.High expression was found in 23 cases and low expression in 65 cases.The chi-square test showed that x~2=43.194,P=0.000,P<0.05,and the difference in CDK4 expression between the two tissues was statistically significant(P<0.05).2.The 5-year survival period of patients with skin melanoma with high CDK4expression was lower than that of patients with low CDK4 expression,and the difference was statistically significant(P<0.05).Use log-rank methodon the comparison of survival,we get x~2=4.126,P=0.042,P<0.05,a high and low expression group average survival period of 29 months,respectively,after 39 months,the median survival period of 24 months respectively,40 months,high expression of 5-year survival rate was 19.1%,5 years of survival rate of 22.9%,low expression group overall survival rate was 21.1%.There was a statistically significant difference between the high expression group and the low expression group(P<0.05).3.There was no significant expression level of CDK4 with sex,age,tumor location and staging difference(P>0.05).The chi-square test showed that the expression of CDK4 was related to the patient’s gender,age,tumor site and stage,and the P values were 0.172,0.647,0.909and 0.767,respectively.The P values were all greater than 0.05,the difference was not statistically significant(P>0.05).4.The expression of CDK4 gene in patients with cutaneous melanoma metastasis was higher than that in patients without cutaneous melanoma metastasis,and the difference was statistically significant(P<0.05).Thirty-one patients had metastasis,including 29 patients with high CDK4expression and 2 patients with low CDK4 expression.There were 64 patients without metastasis,including 42 patients with high CDK4 expression and 22 patients with low CDK4 expression.After statistical software analysis,it is found that Pearson chi-square value is x~2=8.624,P=0.003,P<0.05.CDK4 expression in metastatic melanoma patients was higher than that in non-metastatic melanoma patients,and the difference was significant.Conclusions1.The expression of CDK4 in cutaneous melanoma is higher than that of pigmented nevus,which can be used as an indicator for diagnosing cutaneous melanoma.2.The high expression of CDK4 indicates that the prognosis of skin melanoma patients is poor,and the survival time is short,suggesting that CDK4 may promote the occurrence and development of melanoma,providing theoretical support for diagnosis and treatment.3.The expression of CDK4 in cutaneous melanoma can provide some theoretical support for the development of new targeted drugs for cutaneous melanoma.