[show abstract][hide abstract] ABSTRACT: Proteomics provides a powerful approach for screening alterations in protein expression and post-translational modification associated with particular human diseases. In this study, the analysis of protein expression was focused on malignant melanoma in order to determine the candidate genes involved in tumour progression. The proteomes of cultured melanocytes and of cell lines from primary and metastatic lesions of one malignant melanoma patient were profiled using two-dimensional electrophoresis (2-DE) and mass spectrometry. Differentially expressed proteins were confirmed by 2-DE and mass spectrometry on an additional four malignant melanoma cell lines. Total RNA from the first subset of cell lines was used for quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) of the candidate genes identified after proteomics analysis. A very high similarity was observed in the 2-DE maps of two malignant melanoma cell lines derived from primary and secondary lesions of the same patient. Mass spectrometry identified 37 proteins which were found to be more abundant in tumour cells in comparison with control melanocytes (as confirmed on additional cell lines), with a relatively high prevalence of stress proteins. Eight candidate genes (PRDX2, HSP27, HSP60, HSPA8, HSP9B, STIP1, PDI and P4HB) were further characterized by evaluating their messenger RNA expression levels through real-time RT-PCR analysis. Overexpression of HSP27, HSP60 and HSPA8 and downregulation of PRDX2 were observed in cells from metastatic malignant melanoma in comparison with those from primary melanoma. Although further investigations with larger numbers of paired normal and tumour samples are needed, our findings strongly suggest that the dysregulation of stress pathways may be involved in melanoma progression.
Melanoma Research 07/2005; 15(4):235-244. · 2.52 Impact Factor
[show abstract][hide abstract] ABSTRACT: BackgroundAlthough widely used for the management of patients with cutaneous melanoma, the sentinel lymph node (SLN) biopsy (SNB) procedure
raises several issues. This study was designed to investigate: the predictive factors of SLN status, the false-negative (FN)
rate, and patients’ prognosis after SNB.
Patients and MethodsThis is an observational, prospective study conducted on a large series of consecutive patients (n=1,313) enrolled by 23 Italian centers from 2000 through 2002. A commonly shared protocol was adopted for the SNB surgical
procedure and the SLN pathological examination.
ResultsThe SLN positive and false-negative (FN) rates were 16.9% and 14.4%, respectively (median follow-up, 4.5years). At multivariable
logistic regression analysis, the frequency of positive SLN increased with increasing Breslow thickness (p<0.0001) and decreased in patients with melanoma regression (p=0.024). At the multivariable Cox regression analysis, SLN status was the most important prognostic factor (hazards ratio
(HR)=3.08) for overall survival; the other statistically significant factors were sex, age, Breslow thickness, and Clark’s
level. Considering SLN and NSLN status, including FN cases, we identified four groups of patients with different prognoses.
The 5-year overall survival of patients with positive SLNs was 71.3% in those with negative nonsentinel lymph nodes (NSLNs)
and 50.4% if NSLNs were positive.
ConclusionsRegression in the primary melanoma seems to be a protective factor from metastasis in the SLN. When correctly calculated,
the SNB FN rate is 15–20%. Furthermore, the SNB is important to more precisely assess the prognosis of patients with melanoma.
Annals of Surgical Oncology 16(7):2018-2027. · 4.12 Impact Factor