Cleft Candidate Gene Protein Immunoreactivity in Human Non-Syndromic Cleft Affected Tissue

Objectives. Craniofacial clefts are described as abnormalities of the orofacial region development which are characterized by the incomplete fusion of facial folds. Multiple cleft candidate genes have been associated with craniofacial cleft development, but their exact role is relatively unclear in different cleft types. This research evaluates the immunoreactivity of Homeobox Protein BarH-like 1 (BARX1), Distal-Less Homeobox 4 (DLX4), Forkhead Box E1 (FOXE1), Homeobox Protein Hox-B3 (HOXB3), Muscle Segment Homeobox 2 (MSX2), Sonic Hedgehog (SHH), SRY-Box Transcription Factor 3 (SOX3), Wnt Family Member 3A (WNT3A), and Wnt Family Member 9B (WNT9B) proteins in different cleft tissue while also describing correlations between protein containing cells.
Materials and methods. Non-syndromic cleft affected tissue was gathered from cleft patients who received surgical intervention. Cleft tissue was subdivided based on the tissue type – unilateral cleft lip (n=36), bilateral cleft lip (n=13), cleft palate (n=26). The control group was organized from 7 individuals. Immunohistochemistry was performed. Slides were evaluated with the semiquantitative method. Non-parametric statistical methods were applied. Correlations between the number of factor-containing cells were calculated.
Results. Statistically significant differences were identified for the number of BARX1, FOXE1, HOXB3, MSX2, SHH, SOX3, WNT9B-containing cells between controls and cleft patient groups but no statistically significant differences were found for DLX4 and WNT3A. Several statistically significant correlations between factors were found in each group.
Conclusions. The statistically significant increase of HOXB3 and SHH within unilateral cleft lip tissue signifies their association with this specific cleft type. Transcription factors BARX1, FOXE1, SOX3, and WNT9B are probably involved with the formation of both unilateral cleft lip and bilateral cleft lip, while MSX2 might be pathogenetically involved with all three cleft types. Similar correlations in all evaluated cleft types could indicate the exitance of similar pathogenetic mechanisms within different cleft variations.