Analysis of the DNA content in the progression of recurrent and metastatic melanomas.

Ploidy status and ploidy related parameters of 18 primary melanomas, 32 recurrences and 18 lymphatic metastases were investigated applying CAS200 image analyzer. All the tumours investigated were either suspicious for aneuploidy (Auer III) or clearly aneuploid (Auer IV). Primary melanomas differed from recurrent tumours concerning the percentage of aneuploid cells between 4c and 8c and 5c ER. Comparison of cutaneous tumours with lymphatic metastases showed a significant difference concerning the percentage of aneuploid cells between 2c and 4c. An already high aneuploidy rate in primary tumours suggests that recurrent and metastatic clones of cells are present in early stages and that aneuploidy status in primary melanomas could be regarded as one of the risk factors of recurrences and metastases.

Comparative study of the expression of DNA mismatch repair genes, the adenomatous polyposis coli gene and growth arrest DNA damage genes in melanoma recurrences and metastases.

The main goal of this study was to examine the expression of DNA mismatch repair genes (MLH1, MSH2, PMS1 and PMS2), the adenomatous polyposis coli (APC) gene and growth arrest DNA damage inducible (GADD) genes (GADD34, GADD45 and GADD153) in the different stages of melanoma recurrences and metastases, and to identify any mutual consistencies in their expression pattern. All the cases of primary melanoma examined showed a reduced expression of DNA repair genes. These results demonstrate that disturbances of DNA repair begin in the early stages of melanoma. No significant differences were found in the expression of these markers between cutaneous melanomas and their recurrences and metastases (P> 0.05). Eighteen significant correlations between markers were found in the primary melanomas, and 10 significant correlations were observed in the first recurrences of melanoma. In contrast, 27 statistically significant relationships were demonstrated in metastatic lymph nodes. The different correlations found in primary and metastatic tumours confirmed the hypothetical difference in marker interaction in the diagnostic groups investigated. Our results suggest that DNA repair genes may play an important role in the recurrence and metastasis of melanomas.