Expression and clinical significance of CDK12 and CMTM6 in cutaneous malignant melanoma

Abstract:Objective To study the expression of cyclin dependent kinase 12(CDK12) and CKLF like MARVEL transmembrane domain containing 6(CMTM6) in cutaneous malignant melanoma(CMM) tissues and their clinical parameters and prognostic significance. Methods A total of 122 CMM patients treated in the Department of Dermatology, Baoji People's Hospital from March 2017 to June 2021 were selected. The expression of CDK12 and CMTM6 in patients ' tissues was detected by immunohistochemical staining. Kaplan-Meier method was used to draw the survival curves of CMM patients in different groups. Cox regression model was used to analyze the prognostic factors of CMM. Results The positive rates of CDK12 and CMTM6 in CMM cancer tissues were 60.66 %(74/122) and 63.93 %(78/122), which were higher than 6.56 %(8/122) and 8.20 %(10/122) in adjacent normal skin tissues(χ²/P=80.011/<0.001, 82.187/<0.001). The expression levels of CDK12 and CMTM6 mRNA in CMM cancer tissues were(3.12 ± 0.56) and(2.25 ± 0.42), which were higher than those in adjacent normal skin tissues(0.83 ± 0.26) and(0.75 ± 0.18)(χ²/P=40.967/<0.001, 36.258/<0.001). The positive rates of CDK12 and CMTM6 in cancer tissues of CMM patients with clinical stage ⅢA-B, tumor invasion type and lymph node metastasis were higher than those of patients with clinical stage Ⅰ-Ⅱ, tumor in situ type and no lymph node metastasis(CDK12:t/P=11.285/<0.001, 23.815/<0.001, 12.915/<0.001;CMTM6:t/P=21.295/<0.001, 13.007/<0.001, 7.275/0.007). The 3-year survival rate of CMM patients in CDK12 positive group was 64.86 %(48/74), which was lower than that in negative group 91.67 %(44/48). The 3-year survival rate of CMM patients in the CMTM6 positive group was 66.67 %(52/78), which was lower than that in the negative group 90.91 %(40/44)(Log rank χ²=11.320, 11.580, P<0.001). Clinical stage ⅢA-B, CDK12 positive and CMTM6 positive were independent risk factors affecting the prognosis of CMM patients [OR(95%CI)=1.665(1.145-2.421),1.539(1.209-1.958),1.391(1.139-1.699)].Conclusion The expression of CDK12 and CMTM6 in CMM is significantly increased, which is related to clinical stage ⅢA-B, tumor invasion type and lymph node metastasis, and are markers for prognosis evaluation of CMM.