Telomerase activity in prognostic histopathologic features of melanoma.
BACKGROUND
Telomerase activity (TA) is believed to play a role in the regulation of senescence and to limit the number of cell divisions. The deregulation of telomerase appears to contribute to oncogenesis and the formation of immortal cell lines. As a result, it is believed that it could be used as a prognostic marker in melanoma.


METHODS
TA was assayed by the polymerase chain reaction PCR-ELISA-based telomeric repeat amplification protocol (TRAP assay). One hundred and eight samples were distributed in four histological groups: 30 samples from primary cutaneous melanomas, 24 from peritumoural skin sites, 28 from benign melanocytic lesions, and 26 from normal skin sites as a control.


RESULTS
TA was different among the four tested groups (Kruskall-Wallis test p<0.001), and increasing values of TA were observed progressing from normal skin to benign and then to malignant lesions. Among melanoma samples, there was a significant association between TA and ulceration (p=0.025), TA and vascular invasion (p=0.018) and TA and mitotic rate (p=0.029) (Mann-Whitney test). A linear regression analysis showed significant associations between the increase of TA with Breslow thickness (p=0.004) and the presence of satellites (p=0.002).


CONCLUSIONS
We observed that TA had increased from control skin to peritumoural skin, and then to benign melanocytic lesions and finally to melanoma, suggesting tumour progression. TA showed higher values in the presence of some important histopathologic parameters related to poor prognosis in cutaneous melanoma such as ulceration, vascular invasion, satellites, high rates of mitosis, and in thicker tumours.
Carvalho
Lucia
L
Surgery Department, Plastic Surgery Division, UNIFESP, Federal University of São Paulo, São Paulo, SP, Brazil. lmiiko@yahoo.com.br
Lipay
Monica
M
Belfort
Francisco
F
Santos
Ivan
I
Andrade
Joyce
J
Haddad
Alessandra
A
Brunstein
Flavia
F
Ferreira
Lydia
L
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D003937:Diagnosis, Differential; D018450:Disease Progression; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000175:diagnosis* / Q000473:pathology; D008875:Middle Aged; D009508:Nevus, Pigmented / Q000175:diagnosis; D016133:Polymerase Chain Reaction / Q000379:methods; D011379:Prognosis; D012867:Skin / Q000201:enzymology; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000473:pathology; D019098:Telomerase / Q000378:metabolism*
D014408:Biomarkers, Tumor; D019098:Telomerase