| Objective: According to the World Health Organization,nasopharyngeal carcinoma(NPC)is classified into three major subtypes,including keratinizing squamous-cell carcinoma(K-NPC),non-keratinizing differentiated squamouscell carcinoma(NK-DNPC)and non-keratinizing undifferentiated squamouscell carcinoma(NK-UDNPC).Non-keratinizing undifferentiated squamous cell carcinoma is a goup of heterogeneous subtype,include two major histological subtype,Regaud pattern and Schmincke pattern.Programmed cell death 1(PD-1)is an important immune marker expressed on lymphocytes,and programmed death receptor ligand-1(PD-L1),which helps to suppress T cells,is a marker expressed on tumor cells.T cells have the ability to recognize tumor antigens,induce tumor rejection and kill malignant cells.However,tumor cells can evade the supervise of immune system through a negative immunomodulatory mechanism.This study aims to ivestigate the difference of PD-1/PD-L1 expression in different histological subtypes of NPC,thus provide basic data for further elucidating the regulating mechanism of PD-1/PD-L1 expression in the immune microenvironment of NPC.The data would provide theoretical basis for immunotherapy of NPC.Methods:(1)From 2016 to 2020,183 archive clinical tusse specimens of NK-NPC and 61 non-cancerous nasopharyngeal mucosa tissue specimens were collected from The affiliated Hospital and the Second Affiliated Hospital of Guilin Medical College.The specimens from endoscopic biopsy were paraffinembedded after formalin-fixation.The pathological diagnosis were confirmed by two senior pathologist.(2)the expression of PD-1 and PD-L1 in NPC and non-cancerous nasopharyngeal mucosa was detected by immunohistochemistry.Results: PD-1 protein expressed in the cytoplasm and PD-L1 expressed on the cell membrane.The expression of PD-1 and PD-L1 in NPC was low in nonneoplastic nasopharyngeal mucosa with positive rates as 9.84%(6/61)和13.11%(8/61)respectively.PD-1 was differentially expressed in histological subtypes of NPC.19.05%(4/21)of the NK-DNPC cases were negative,19.05%(4/21)weakly positive,33.33%(7/21)moderately positive and 28.57%(6/21)strongly positive.In NK-UDNPC cases,PD-1 were differentially expressed in two major histological pattern.In Regaud pattern,37.93%(44/116)were weakly positive,25.86%(30/116)were moderately positive,and 24.14%(28/116)were strongly positive.Whereas in Schmincke pattern,10.87%(5/46)was weakly expressed,15.22%(7/46)was moderately expressed,and 69.57%(32/46)was strongly expressed.In NK-DNPC,the expression of PD-L1 was negative in 33.33%(7/21)cases,weakly positive in 33.33%(7/21),moderately positive in 4.76%(1/21),strongly positive was 28.57%(6/21).PD-L1 were also differentially expressed in two major histological pattern of NK-UDNPC.In Regaud pattern,43.10%(50/116)of cases were weakly positive,31.03%(36/116)were moderately positive and 25.87%(30/116)was strongly positive.Whereas in Schmincke pattern,weak positive expression was 6.52%(3/46),moderate expression was 6.52%(3/46),and strong expression was 86.96%(40/46).Conclusion: The expression level of PD-1 and PD-L1 in NPC was higher than that in non-canceous nasopharyneal mucosa.The expression level of PD-1in Schmincke type was higher than that in Regaud type,but the expression level of PD-1 in non-keratinizing differentiated squamous-cell carcinoma was not significantly different from that in Schmincke type and Regaud type.The expression level of PD-L1 in Schmincke squamous-cell carcinoma was higher than that in Regaud and non-keratinizing differentiated squamous-cell carcinoma.These data suggest that PD-1/PDL-1 were differentially expressed in histological subtypes of NPC,and that immno-microenviromental difference exists.This study provides a new perspective for the immunotherapy and prognosis of different histological subtypes of NPC. |
