Effect Of Nimotuzumab And TP Preoperative Induction Chemotherapy On PD-L1 Expression In Oral Squamous Carcinoma

Objective:1.We analyzed the correlation between the expression of PD-L1 and the clinicopathological characteristics of OSCC by detecting the expression of programmed cell death ligand 1(PD-L1)in oral squamous cell carcinoma(OSCC)and paraneoplastic tissues.2.The effect of nimotuzumab and preoperative induction chemotherapy on PD-L1 expression was analyzed by detecting the changes in PD-L1 expression in OSCC tissues before and after nimotuzumab(N)combined with TP preoperative induction chemotherapy and single TP induction chemotherapy.Methods:1.The expression of PD-L1 protein and PD-L1 m RNA in OSCC and paraneoplastic tissues was detected by immunohistochemistry(IHC)and real-time quantitative PCR(RT-qPCR)in 33 patients with OSCC.The correlation between the expression of PD-L1 and the clinicopathological features of OSCC was discussed.2.Twenty-five patients with locally advanced oral squamous carcinoma who presented to our department were selected,and all of them received preoperative induction chemotherapy and surgery.They were divided into two groups,a single induction chemotherapy group TP(docetaxel + cisplatin)versus N+TP(nimotuzumab +docetaxel + cisplatin)group.Among them,18 cases were in the N+TP group and 7 cases were in the TP group.The effect of nimotuzumab and preoperative induction chemotherapy on PD-L1 expression was analyzed by detecting changes in PD-L1 expression in specimens from both groups before and after drug administration by IHC and RT-qPCR.SPSS 26.0 software was used to statistically analyze the data,including χ2test,t-test,and rank sum test,and the results were considered statistically significant differences at P<0.05.Results:1.Expression and clinical significance of PD-L1 in oral squamous carcinoma:(1)IHC findings revealed results showed that the positive expression of PD-L1 protein was higher in OSCC tissues compared with paraneoplastic tissues(P<0.05).The high expression of PD-L1 protein was significantly correlated with TNM stage and lymph node metastasis of oral squamous cell carcinoma(P<0.05);However,it was not associated with the degree of differentiation(P>0.05).(2)RT-qPCR results showed that the relative expression of PD-L1 m RNA in OSCC tissues was significantly higher than that in paraneoplastic tissues(P<0.05).2.Differences in expression of PD-L1 in locally advanced OSCC tissues before and after preoperative induction chemotherapy with nimotuzumab:The results of IHC and RT-qPCR showed that the expression of PD-L1 protein and the relative expression of PD-L1 m RNA in OSCC tissues in the N+TP group and TP group after drug administration were significantly decreased,with statistical differences(P<0.05).However,there was no statistical difference in the amount of PD-L1 protein and m RNA downregulation between the two groups(P>0.05).Conclusion:1.Overexpression of PD-L1 in OSCC tissues;2.High expression of PD-L1 was significantly correlated with TNM stage and lymph node metastasis in OSCC;3.Both N+TP and TP preoperative induction chemotherapy regimens can downregulate the expression of PD-L1 in OSCC tissues;4.Nimotuzumab may not be involved in the downregulating expression of PD-L1 in OSCC tissues.