Seventy-five microarrays (the adult samples) had been hybridized earlier; their data files were used in a previously published studies using different comparisons [31]�C[32] and are selleckchem available in the Gene Expession Omnibus database (series accession number: “type”:”entrez-geo”,”attrs”:”text”:”GSE10714″,”term_id”:”10714″GSE10714 and “type”:”entrez-geo”,”attrs”:”text”:”GSE37364″,”term_id”:”37364″GSE37364). The datasets of the newly hybridized 6 microarrays are registered on the “type”:”entrez-geo”,”attrs”:”text”:”GSE37267″,”term_id”:”37267″GSE37267 serial accession number. Control children were referred to the outpatient clinic with rectal bleeding, constipation or chronic abdominal pain. Ileocolonoscopy was part of their diagnostic procedure (exclude organic disease) and the biopsy specimens showed normal macroscopic appearance and histology.

Every specimen was verified by histopathologists. For immunohistochemistry colorectal biopsy samples were routinely fixed in formaldehyde and embedded in paraffin wax. For mRNA studies, colonoscopy samples were stored in RNALater Reagent (Qiagen Inc, Germantown, US) at ?80��C before total RNA extraction for gene expression analysis and Taqman RT-PCR study. Ethical approvals (Nr.: 69/2008 and 202/2009) for this study were issued by the Regional and Institutional Committee of Science and Research Ethics of Semmelweis University (Budapest, Hungary). Written informed consent was obtained in advance from all adult participants and from the next of kin, caretakers, or guardians on the behalf of the minors/children approved by the ethics committees.

Detailed clinicopathological specification of the patient samples are summarized in Table 1 and Table 2. Table 1 Subgroups of patients participating in immunohistochemistry, microarray analysis and PCR validation with the number of samples and mean age values. Table 2 Clinical features of healthy children controls participating in immunohistochemistry, microarray analysis and PCR validation. Immunohistochemistry for cell proliferation Archived samples from 14 histologically normal colonic biopsies from children, 10 normal colonic biopsies from adults, as well as 10 adult adenomas and 10 CRCs were collected during Carfilzomib routine endoscopy. 1 mm-diameter cores were punched out from paraffin blocks of adult samples and collected into tissue microarrays (TMA). Four ��m thick sections cut both from the TMAs and from individual children biopsy samples were dewaxed and rehydrated for immunostaining. After antigen retrieval in a pH 9.