Significance Of KIF3B Expression In HER2 Positive Breast Cancer And Its Correlation With Epithelial-mesenchymal Transformation

Objective:The aim of this artical are investigating the significance of KIF3B expression and its correlation with EMT in HER2-positive(amplification/overexpression)breast cancer,and analyzing the relationship between KIF3B and the clinicopathologic characteristics(age,site,size,pathological type,histological classification,and lymph node metastasis)in HER2-positive patients.It provides important clues and theoretical basis for screening new target molecules of HER2-positive breast cancer.Methods:Collected 60 cases of HER2 positive breast cancer tissues and adjacent tissues in the Affiliated Hospital of Qingdao University during 2017～2018.Collected and analyzed the statistics of clinicopathological characteristics.Detected the expression of KIF3B and EMT related proteins(E-cad,Vimentin,Slug,Twist)in HER2-positive breast cancer tissues and adjacent tissues by immunohistochemical methods.Then,analyzed the significance of KIF3B in HER2 positive breast cancer and its correlation with epithelial-mesenchymal transformation by statistical methods.Results:(1)The clinicopathological features of HER2-positive breast cancer:the age were 28～74 years old,the mean age was 54.5 years old,and the median age was 55 years old.There were 46(76.7%)post-menopausal patients.34(43.3%)patients occurred in right breast.The maximum diameter was 0.4～8cm,the average maximum diameter was2.2cm.Most(93.3%,56/60)of them were invasive ductal carcinoma and non-special type.All of the patients were diagnosed with histological grade II(18 cases)and grade III(42cases).The lymph node metastasis rate was 43.3%(26/60).(2)Histomorphological characteristics of HER2 positive breast cancer:the histological grades of all the 60 cases were medium to high grade(grade II or III).The main features included that the growth pattern of the cancer tissue was invasive.And the cancer cells arranged into nested,solid,sieve or cord-like structures with several mixed forms.The proportion of glandular ducts in carcinoma tissues is low.Most of the ducts are poorly formed and have a variety of morphology.The well-differentiated ducts are relatively rare,and the ducts often fuse with each other in the form of sieve or solid sheet.Compared with low-grade breast cancer cells,these cells showed obvious atypia and pleomorphism,active growth,significantly increased cell volume,vacuolated nuclei,large and clearly visible nucleoli and nuclear mitosis with pathological mitosis.(3)The expression rates of KIF3B,Vimentin,Slug,Twist and E-cadherin in HER2 positive breast cancer tissues were 70%,66.7%,63.3%,58.3%and 53.3%.The expression rates of KIF3B,Vimentin,Slug,Twist and E-cadherin in adjacent tissues were 30%,40%,31.7%,35%and 73.3%.(4)The expression of KIF3B was associated with lymph node metastasis(χ~2=9.079,P=0.003).The expression rate of KIF3B in lymph node positive patients was highly about 92.3%(24/26).There was no correlation with age,tumor site,tumor size,and histological grade(P>0.05).(5)The expression of Vimentin was positively correlated with Slug and Twist in HER2 positive breast cancer(P<0.05),and the correlation coefficients were 0.489 and0.335.The expression of E-cadherin was negatively correlated with Slug and Twist(p<0.05),and the correlation coefficients were-0.396 and-0.316.(6)KIF3B was negatively correlated with the expression of epithelial marker E-cadherin(r=-0.316,P<0.05),while it was positively correlated with the expression of Slug,Twist which were nuclear transcription factors and Vimentin which was mesenchymal marker(P<0.05).The correlation coefficients were 0.408,0.258 and 0.05.Conclusion:KIF3B may be involved in the epithelial-mesenchymal transformation process of HER2-positive breast cancer tissue and promote the process.