Expression Of EMT Marker(E-cadherin、N-cadherin) And Their Clinical Significance In Neuroblastoma

Objective:Neuroblastoma(NB)is a common extracranial solid tumor in children,accounting for up to 10% of childhood malignancies.It is highly heterogeneous and has a great difference in clinical prognosis.NB accounts for 12 to 15 percent of all childhood cancer deaths.The median age at diagnosis of NB is 17 to 18 months,and approximately 40% of patients are younger than 1 year of age at diagnosis,while less than 5% are older than 10 years.Epithelial-mesenchymal transformation(EMT)is one of the important mechanisms of invasion and metastasis of malignant tumors,which can cause mobile cells to migrate and spread far away.EMT is involved in the metastasis of more than 90% of malignant epithelial tumors,such as lung cancer,liver cancer,breast cancer,prostate cancer,colon cancer and pancreatic cancer.At present,the relationship between this mechanism and neuroblastoma is rarely studied.EMT is a complex process,which involves many related signaling molecules.The expression of E-cadherin is decreased while that of N-cadherin is up-regulated,among which the decreased expression of E-cadherin is the main marker of EMT.N-MYC is a member of the MYC proto-oncogene family,whose abnormal expression is responsible for many human cancers.N-MYC amplification alone accounts for 25% of NB cases and is the most important biomarker for poor survival in NB.Clear clinical risk and staging are important in developing treatment and prognosis assessments.Age,tumor differentiation degree nmyc and histological type gene amplification are important prognostic indicators,but these indicators cannot fully reflect the nature of tumor invasion,metastasis and growth.In this study,the expression and clinical significance of EMT markers E-cadherin and N-cadherin in neuroblastoma were investigated.Methods:(1)A total of 94 cases of peripheral neuroblastic tumors were collected from the Department of Pathology of Jiangxi Children’s Hospital from January 2010 to June2020.The diagnostic criteria were determined according to the Consensenus for Pathological Diagnosis of Peripheral Neuroblastic Tumors.A total of 46 cases with complete clinical data were included in this study.(2)Expression of E-cadherin,N-cadherin and anaplastic large cell lymphoma(ALK)protein were detected by immunohistochemical method.(3)Fluorescence in situ hybridization was used to detect N-myc gene amplification.Results:(1)Among the 46 NB patients,24 were boys and 22 were girls.The mean age of treatment was 24 months(age range 0.3 to 144 months),and 28 cases were ≤18months(15 cases of neonatal NB),>18 cases in 18 months;12 cases of adrenal glands and 34 cases of extradrenal glands(including neck,mediastinum,pelvis and abdominal cavity,sacrococcyx,waist and thigh)were examined.The clinical stages were 23 cases in stage I ～II and 23 cases in stage III ～ IV.(2)Among the 46 cases,40 cases were neuroblastoma(NB)and 6 cases were gangliocytic neuroblastoma(GNB).Among the 40 NB cases,95%(38 cases)were poorly differentiated(Table 1),2.5%(1 case)were undifferentiated,and 2.5%(1 case)were differentiated,with good prognosis(FH type,27 cases)and poor prognosis(UH type,13 cases).Among the 6 GNB cases,1 was nodular type(UH type)and 5 were mixed type(FH type).(3)65% of the patients with stage III-IV NB expressed ALK protein positively,and the difference was statistically significant compared with those with stage II-II NB(P=0.018).ALK protein was expressed in 81% of patients with positive N-myc gene amplification,and the difference was statistically significant compared with those with negative N-myc gene amplification(P=0.010).The positive rate of ALK protein in 40 NB patients was 55%,and the difference was statistically significant compared with GNB(P=0.038).(4)E-cadherin expression was negative in 31(67.4%)and positive in 15(32.6%)of 46 NB patients.The negative expression rate of E-cadherin in UH type NB was92.9%,and the difference was statistically significant compared with FH type NB(P=0.036).87% of patients with stage III-IV NB expressed E-cadherin negatively,and the difference was statistically significant compared with patients with stage II-II NB(P=0.005).The expression of E-cadherin was not correlated with gender,age,ALK protein and N-myc gene abnormalities(P=0.174,0.334,0.46,1.000).E-cadherin protein expression in >12-month-old NB was correlated with clinical stage(P=0.031).It was not associated with histological types(FH/UH),abnormalities of ALK protein and N-myc gene(P=0.127,0.303,0.266).The expression of E-cadherin protein in NB≤12m months was not correlated with clinical stage,histological type(FH/UH),ALK protein and N-myc gene abnormalities(P=0.218,0.262,1.000,0.163).(5)N-cadherin was positive in 22 and negative in 24 of 46 NB patients;The positive expression rate of N-cadherin in UH type NB was 71.4%,and the difference was statistically significant compared with FH type NB(P=0.034).N-cadherin was detected in 69.6% of patients with stage III-IV NB,and the difference was statistically significant compared with those with stage II-II NB(P=0.003).The positive expression rate of N-cadherin in ALK-positive NB was 68.2%,and the difference was statistically significant compared with that in ALK-negative NB(P=0.008).The expression of N-cadherin was not correlated with gender and age(P=0.143,0.979).80%>12-month NB patients expressed ALK protein(P=0.023).The expression of N-cadherin was not correlated with histotype or N-myc gene abnormality(P=0.370,0.303).The expression of N-cadherin protein in NB ≤12m months was not correlated with clinical stage,histologic type,ALK protein and N-myc gene abnormalities(P=0.105,0.085,0.431,0.190).Conclusion:(1)There is epithelial mesenchymal transition in neuroblastoma.(2)The clinical significance and mechanism of epithelial mesenchymal transition may be different in neuroblastoma > 12 months old and ≤ 12 months old.(3)The poor prognosis of neuroblastoma aged > 12 months may be related to epithelial mesenchymal transition.