[Expression of lnc-MyD88 and its relationship with the prognosis of patients with epithelial ovarian cancer].

Objective: To explore the expression of long non-coding RNA-myeloid differentiation factor 88 (lnc-MyD88) and its relationship with the prognosis of patients with epithelial ovarian cancer (EOC). Methods: A total of 70 EOC patients who underwent initial cytoreductive surgery and platinum-based drugs combined with paclitaxel for 6 to 8 courses were selected at Sichuan Cancer Hospital from January 2016 to January 2019. The fresh cancer tissue specimens were collected. In addition, 28 fresh normal ovarian tissues from patients who underwent surgery for benign gynecological diseases during the same period were collected as control group. Reverse transcription (RT) and real-time quantitative polymerase chain reaction (qPCR) were used to detect the expression of lnc-MyD88 and myeloid differentiation factor 88 (MyD88) mRNA in EOC tissues and normal ovarian tissues. The correlation between the expression of lnc-MyD88 and MyD88 mRNA in EOC was analyzed by Pearson's correlation coefficient. The relationship between lnc-MyD88 expression and clinicopathological characteristics of patients with EOC was analyzed. Kaplan-Meier method was used to calculate the survival rate of patients. The log-rank test was used for univariate survival analysis, and Cox proportional hazard model was used for multivariate survival analysis. Results: (1) RT-qPCR showed that the relative expression level of lnc-MyD88 and MyD88 mRNA in EOC were 0.009 (0.000-0.049) and 0.001 (0.000-0.006), respectively, which were significantly higher than those of normal ovarian tissues (all P<0.01); Pearson's correlation coefficient showed that the expression of lnc-MyD88 and MyD88 mRNA in EOC was positively correlated (r2=0.610, P<0.01). (2) The high expression rate of lnc-MyD88 in EOC patients with lymph node metastasis, distant metastasis and chemotherapy resistance (71%, 64% and 70%, respectively) were significantly higher than the patients in control group (41%, 40% and 35%, respectively; all P<0.05). There were no statistically significant in the high expression rate of lnc-MyD88 in EOC patients with different ages, pathological types, pathological grades, surgical pathological stages, postoperative residual lesion size, and ascites cancer cells (all P>0.05). (3) Univariate analysis showed that surgical pathological staging, lymph node metastasis, distant metastasis, postoperative residual tumor size, and high expression of lnc-MyD88 and MyD88 mRNA significantly affected the progression-free survival (PFS) and overall survival (OS) of EOC patients (all P<0.05), ascites cancer cells were the risk factors that significantly affected PFS in EOC patients (P=0.040); multivariate analysis showed that surgical pathological staging and high expression of lnc-MyD88 and MyD88 mRNA were independent factors affecting PFS and OS in EOC patients (all P<0.05), the size of residual lesions after surgery was an independent factor affecting PFS in EOC patients (P=0.001). Conclusions: The level of lnc-MyD88 expression in ovarian cancer tissues was significantly increased. Lnc-MyD88, as a molecular marker for the poor prognosis of EOC, is related to the expression of MyD88 in EOC, and may be involved in its expression regulation, thereby affecting the survival and prognosis of EOC patients.