Cell cycle mediators and hypothesis of cancer stem cells in oral squamous cell carcinoma

ABSTRACT

Deeper understanding of Oral Squamous Cell Carcinoma [OSCC] biology through detection of cell cycle mediators monitored by apoptosis-related genes; p53, p21 and Bcl2; and the proliferation indicator; ki67. furthermore, discussion of the hypothesis of cancer stem cell biology in OSCC would be highlighted. Thirty selected cases of moderately differentiated OSCC were archivd and immunohistochemically stained using a panel of antibodies including apoptotic mediators; p53, p21, Bcl2 and proliferation marker; ki67. Immunoexpression was scored using a semiquantitative scale. The clinico-pathological data of the selected cases demonstrated that the mean age was 46.9 +/- 8.2 ranging from 29 to 67 years. Tongue was the most commonly affected site, followed by the palate then the floor of the mouth and the gender-site relation was variable. On the other hand, the degree of staining regarding the percentage of positively reacted cases revealed all the cases were positive with ki67 biomarker and a relatively high percentage of cases were positive to p53 and Bcl2 while 43.3% of cases were negative to p21. A common trait for the studied cell cycle indicators was that the peripheral and para-peripheral cells of the invading nests were the harbor of the immunoreactivity. Assessment of the studied cell cycle regulators may be valuable to judge tumorigenesis of OSCC. Furthermore, deregulation of cell control might aid in the attainment of genetic changes in normal stem cells to be altered to cancer stem cell