Survivin, bcl-2, bax, and bcl-X gene expression in sentinel lymph nodes from melanoma patients

The expression of apoptosis-related genes, such as survivin, bcl-2, bcl-X, and bax, has been evaluated by reverse transcriptase polymerase chain reaction (RT-PCR) and by immunohistochemistry in sentinel lymph nodes (SLNs) from melanoma patients and then correlated to the outcome of patients.

Thirty-six SLNs were examined. After RNA extraction, an RT-PCR followed by Southern blot hybridization was performed to detect survivin, bcl-2, bcl-X, and bax mRNA. bcl-2, survivin, and bax gene expression was evaluated, whenever possible, also by immunohistochemistry at the protein level.

We found a significant correlation (P <.005) between survivin expression and outcome of patients; in fact, 61.5% of patients expressing survivin gene progressed or died because of the disease, whereas 38.5% are currently disease-free. Among patients negative for survivin expression, 100% are disease-free after a median follow-up time of 52.9 months. We did not find a significant correlation between bcl-2, bax, and bcl-X gene expression and outcome of patients. In fact, these genes were found equally expressed in patients with disease progression and in disease-free patients.

Our findings show a variable expression of apoptosis-related genes in SLNs of melanoma patients; more interestingly, we found that survivin expression correlates to outcome of patients in a statistically significant way, whereas the expression of other genes, such as bcl-2, bax, and bcl-X, did not seem to correlate to progression of disease. We suggest that the detection of survivin gene expression by RT-PCR in SLNs may be a useful prognostic indicator.