Evaluation of combined h-TERT, bcl-2, and caspases 3 and 8 expression in cutaneous malignant melanoma based on tissue microarrays and computerized image analysis.
OBJECTIVE
Deregulation of apoptotic pathways in cutaneous malignant melanoma appears to be correlated with chemoresistance and poor prognosis. Furthermore, telomerase (especially h-TERT) expression induces proliferation and also represents a potential target for vaccination regarding some types of malignancies.


METHODS
Using tissue microarrays (TMA) technology, 25 paraffin-embedded tissue samples of histologically confirmed malignant melanomas were cored at a diameter of 2 mm and re-embedded into one recipient block (final TMA density 24/25-96%). Immunohistochemistry (IHC) was performed by the use of anti-bcl-2, anti-caspase 3, anti-caspase 8 and anti- h-TERT antibodies. Protein expression levels were evaluated using a computerized image analysis system (CIA). SPSS (chi square test and inter-rater kappa) was used for statistical analysis.


RESULTS
Strong protein expression was observed in 1/24 (4.1%), 1/24 (4.1%), 2/24 (8.2%), and 4/24 (16.4%) cases regarding h-TERT, caspase 3, caspase 8 and bcl-2, respectively. Moderate was observed in 7/24 (29.1%), 8/24 (32.2%), 5/24 (20.2%), and 8/24(32.2%) cases, whereas reduced or absent expression demonstrated 16/24 (65%), 15/24 (60.2%), 17/24 (68.5%), and 12/24 (50 %) cases. Statistical significance was assessed correlating age to caspase 3 (p=0.05), Breslow's thickness to telomerase (p=0.013) and to bcl-2 (p=0.053), Clark's level to telomerase (p=0.008) and to bcl-2 (p=0.022), and finally ulceration to telomerase expression (p=0.007).


CONCLUSIONS
bcl-2 and telomerase expression are correlated to critical parameters of malignant melanoma, affecting its biological behavior. Furthermore, downregulation of proteins such as caspases 3/8, which normally induce apoptosis, is perhaps associated with resistance of the applied chemotherapeutic strategies in this type of malignancy.
Zygouris
P
P
Lamia Institution of Technology, Lamia, Greece.
Tsiambas
E
E
Tiniakos
D
D
Karameris
A
A
Athanassiou
A E
AE
Kittas
Ch
Ch
Kyroudi
A
A
D014408:Biomarkers, Tumor / Q000032:analysis / Q000378:metabolism*; D053148:Caspase 3 / Q000032:analysis / Q000378:metabolism; D053181:Caspase 8 / Q000032:analysis / Q000378:metabolism; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007150:Immunohistochemistry; D008297:Male; D008545:Melanoma / Q000175:diagnosis* / Q000473:pathology; D008875:Middle Aged; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis / Q000378:metabolism; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000473:pathology; D019098:Telomerase / Q000032:analysis / Q000378:metabolism; D046888:Tissue Array Analysis
D014408:Biomarkers, Tumor; D019253:Proto-Oncogene Proteins c-bcl-2; C509186:TERT protein, human; D019098:Telomerase; D053148:Caspase 3; D053181:Caspase 8