The purpose of the study was to determine the frequency of expression p53 and p16INK4a
proteins and bcl-2
oncoprotein in malignant skin
melanoma and to determine their correlation with the proliferative index and
tumor thickness. The study involved 53 patients: 27 (51%) male and 26 (49%) female. Mitotic index showed a correlation with p53
protein expression, a negative correlation with
p16INK4a protein expression. Statistically significant correlations were determined between the Breslow
tumor thickness, Clark invasion level and p53
protein expression, as well as Breslow
tumor thickness and bcl-2
oncoprotein expression (p<0.05), whereas there was no correlation between the
p16INK4a protein expression and
melanoma thicknes and Clark invasion level. Overexpression p53
protein and bcl-2
oncoprotein, with the loss
p16INK4a protein of expression in the nodular
melanoma, confirms a frequent loss of function of these tumor suppressor gene and oncogene, and indicates a vertical
tumor growth phase. The loss of
tumor suppression function the p53
protein and bcl-2
oncoprotein overexpression in cutaneous
melanoma correlates with larger
tumor thickness, whereas the overexpression of mutated p53
protein and loss
p16INK4a protein of expression indicate a higher proliferative tumour potential. Therefore, these evaluated
proteins may be the aggressive
biological tumour activity markers.