Effect And Mechanism Study On The Canonical Wnt Signaling Pathway In Hirschsprung Disease

Objectives To explore a possible genetic basis of pathological process of Hirschsprung disease(HD) by studing the expression levels of some key proteins, including WNT8 b, DVL-3 and β-cateinin in Canonical wnt signaling pathway in the colon tissues of children with HD.Methods The ganglionic(normal group)and aganglionic(lesion group) segment of colon tissues in 44 cases of HD patients who underwent difinitive surgery in Shanghai Jiaotong University Affiliated Children’s Hospital during June 1st,2012 to March 31 st, 2015 were collected as exprimental group, meanwhile, the well-developed colon tissues in 6 cases of anorectal malformation(ARM) patients who underwent colostomy in our Hospital were collected as control group. The experimental group were subdivided into 4 groups according to the pathologic extent of aganglionic bowel: short-segment group(6 cases), classic extent group(28 cases), long-segment group(7 cases) and total colonic ganglionsis(3 cases).The protein levels of WNT8 b, DVL-3 and β-cateinin in colon tissues of experimental group and control group were confirmed by immunohistochemical staining and its semi-quantitive value were detected by Qwin V3 application. SPSS17.0 application were applied for data analysis and p < 0.05 were considered statistically significant.Results(1) The protein levels of WNT8 b and DVL-3 in colon tissues were positively correlated and this kind of protein levels correlationship also occurs between DVL-3 and β-cateinin. the correlation coefficient is 0.823 and 0.855 respectively.(2) The protein levels of WNT8 b, DVL-3 and β-cateinin in lesion group were higher than that in normal group and control group(p < 0.05); but shown no statistical differences between normal group and control group, respectively.(3) The expression levels of this three key proteins in canonical wnt signaling pathway increased with the pathologic extent of aganglionic bowel and this expression levels were much higher in total colonic aganglionsis group than in shortsegment group( p < 0.05), but shown no differences between the subgroups of normal group.(4) This three proteins were meanly expressed in the mucus and submucus layer of aganglionic segment of colon tissues, whose values were much higher than those measured in the myenteric layer of aganglionic colon segment andmucus and submucus layer of lesion group and control group; The protein levels of WNT8 b, DVL-3 and β-cateinin were shown no differences in the mucosa and submucosa layer of colon tissus in normal group and control group.Conclusions This study of the expression patterns in colon tissues of three key proteins showed that Canonical wnt signaling pathway were abnormally upregulated in the aganglionic segment colon tissues of HD patients, which suggests that this sgnaling pathway may play a role in the pathogenosis of HD. This experiment may reveal another genetic basis of HD, which may provide some help for the genetic diagnosis and targeted therapy in the future.