SEPTIN9与HOXA9基因甲基化在鉴别阑尾和卵巢来源腹膜假黏液瘤中的诊断价值OA

Objective:Pseudomyxoma peritonei(PMP)is a rare peritoneal malignant tumor syndrome,and its origin is difficult to distinguish.This study aims to explore the methylation levels of SEPTIN9 and HOXA9 genes in PMP originating from appendiceal mucinous neoplasms-PMP(AMNs-PMP)and ovarian mucinous tumors-PMP(OMTs-PMP),and their significance in distinguishing PMP. Methods:Methylation-specific polymerase chain reaction(MS-PCR)was used to detect the methylation levels of SEPTIN9 and HOXA9 genes in a normal appendix control group(APD control,n=10),a normal ovary control group(OV control,n=17),a AMNs-PMP group(n=40),and a OMTs-PMP group(n=19).Immunohistochemical detection of cytokeratin(CK)7 and CK20 was performed on tissue samples from the AMNs-PMP group and the OMTs-PMP group.The expression of SEPTIN9 and HOXA9 gene methylation in the AMNs-PMP group and the OMTs-PMP group was analyzed by t-test,and the role and value of combined immunohistochemical detection were analyzed. Results:The positivity rate of SEPTIN9 gene methylation in the AMNs-PMP group was significantly higher than that in the OMTs-PMP group(92.5%vs 63.2%,P＜0.01).The positive rate of HOXA9 gene methylation in the OMTs-PMP group was significantly higher than that in the AMNs-PMP group(94.7%vs 12.5%,P＜0.001).The ΔCt value of HOXA9 gene methylation in the OMTs-PMP group was significantly lower than that in the AMNs-PMP group(3.20±0.47 vs 8.63±0.61,P＜0.001).The positivity rate of CK7 in the OMTs-PMP group was significantly higher than that in the AMNs-PMP group(94.7%vs 17.5%,P＜0.001),whilie the positivity rate of CK20 in the AMNs-PMP group was significantly higher than that in the OMTs-PMP group(97.5%vs 63.2%,P＜0.001).CK7(-)CK20(+)and SEPTIN9(+)HOXA9(-)gene methylation had high sensitivity(82.5%vs 87.5%)and specificity(both 94.7%)in diagnosing of AMNs-PMP.CK7(+)CK20(-)and SEPTIN9(-)HOXA9(+)gene methylation had low sensitivity(both 36.8%)and high specificity(97.5%vs 92.5%)in the diagnosing of OMTs-PMP.while CK7(+)HOXA9(+)had higher sensitivity(89.5%)than the previous 2 combinations with a similar specificity. Conclusion:Utilization of SEPTIN9(+)HOXA9(-)can be used for diagnosing AMNs-PMP,and CK7(+)HOXA9(+)can be used for diagnosing OMTs-PMP.Methylation of HOXA9 and SEPTIN9 genes can serve as potential biological markers for the differential diagnosis of AMNs-PMP and OMTs-PMP.