Immunohistochemical expression of HOXA1, and Ki-67 proteins of oral squamous cell carcinoma

Abstract

Background: Oral squamous cell carcinoma (OSCC) is the most prevalent malignant neoplasm of the oral cavityand constitutes a major health problem in developing. In the last 30 years, the 5-year survival rate of patients withoral SCC has not improved despite advance in diagnostic techniques. To improve early diagnosis for this deadlydisease, new biological markers are needed. HOX genes encode homeodomain-containing transcription factorsinvolved in the regulation of cellular proliferation and differentiation during embryogenesis. HOX gene expression hasbeen described in several adult tissues, where they performed important roles in maintaining homeostasis. Fewstudies have suggested that HOXA1 plays a role in tumorigenesis. Besides being overexpressed in several tumors,HOXA1 influences numerous cellular processes including proliferation, apoptosis and epithelialmesenchymaltransition (EMT), and HOXA1 overexpression is sufficient for malignant transformation ofnontumorigenic epithelial cells.Ki-67 is a specific marker of proliferation and the expression of which is strictly associated with cell proliferation and iswidely used in pathology as a proliferation marker to measure the growth fraction of cells in human tumors.The aimsof this study were to evaluate the immunohistochemical expression of HOXA1 & Ki-67 in OSCC & to correlate theexpression of the studied markers with the clinicopathological findings and with each otherMaterials and Methods: Thirty formalin-fixed, paraffin- embedded tissue blocks of oral squamous cell carcinoma wereincluded in this study. H&E stain was done for each block for reassessment of histological examination. Animmunohistochimical stain was performed using anti HOXA1 and anti Ki-67 poly clonal antibodies.Results:The expression of HOXA1 and Ki-67were positive in all oral squamous cell carcinoma cases & in all layers(100%), while the expression was restricted to the basal and supra basal layer in normal oral mucosa. Statisticallynon-significant correlation observed between each marker with clinico-pathological parameters. While a statisticallysignificant association was found between the expressions of two markers, (p-value= 0.027).Conclusion: The statistically significant association observed between expressions of HOXA1 with the specific markerof proliferation Ki-67. This suggested important role in oral SCC development and progression.

Keywords

OSCC, HOXA1, Ki-67