Prognostic factors in melanoma outcome and survival

Locally generated VGVAPG and VAPG elastin-derived peptides amplify melanoma invasion via the galectin-3 receptor

Melanomas containing more elastin are associated with higher stages of the disease. The interaction between elastin-derived peptides and melanoma cells appears to play an important role in the progression of melanomas. The effects of the elastin-derived peptides VGVAPG and VAPG have been investigated on the migration, invasion, adhesion and angiogenesis of human melanoma cells of different invasive potential. Elastin, tropoelastin and VGVAPG peptide were demonstrated at the invasion site of melanoma using histochemistry and immunohistochemistry. Not only the VGVAPG elastin-derived peptide, which exhibits the XGXXPG consensus sequence in its primary structure, but also the shorter VAPG bind directly to 3 cell surface receptors: galectin-3, integrin alpha v beta 3 and elastin-binding protein. Our results suggest that the increased levels of elastin-derived peptides facilitate the invasion of melanoma cells: (i) VGVAPG and VAPG elastin-derived peptides are chemotactic for melanoma cells; (ii) they can increase the migration of melanoma cells and the expression of CXCR-4 and CXCL-12 chemokines; (iii) they enhance the expression of the elastin-degrading MMP-2 and MMP-3; (iv) they increase the attachment of melanoma cells and the expression of different adhesion molecules; (v) they increase the expression of the lymphangiogenic VEGF-C and (vi) the galectin-3 receptor can mediate all these effects. Clinical and therapeutic aspects are also discussed.

Epigenetic up-regulation of C-C chemokine receptor 7 and C-X-C chemokine receptor 4 expression in melanoma cells

Histone deacetylation and DNA methylation establish epigenetic modifications, which through chromatin remodeling may result in gene silencing. We hypothesized that chemokine receptors C-C chemokine receptor 7 (CCR7) and C-X-C chemokine receptor 4 (CXCR4) on melanoma cells undergo epigenetic regulation. We investigated whether a histone deacetylase inhibitor and a demethylating agent influence CCR7 and CXCR4 expression on melanoma cells. Initially, microarray analysis was done to screen changes in chemokine receptor expression on melanoma cells after treatment with trichostatin A (TSA) and 5-Aza-2-deoxycytidine (5-Aza). CCR7 and CXCR4 mRNA expression were uniformly altered and selected for further investigation. Quantitative real-time reverse transcription-PCR assay, immunohistochemistry, and Western blot analysis were used to assess changes in mRNA and protein expression induced by TSA and 5-Aza in melanoma lines. Cell migration assays were conducted to assess the effects of altered CCR7 and CXCR4 expression on cell function. Treatment with TSA or 5-Aza increased gene expression of both CCR7 and CXCR4 in melanoma lines. TSA was the strongest enhancer. With combined treatment, CCR7 and CXCR4 mRNA expression was also up-regulated. Immunohistochemistry after combined treatment showed enhanced staining of both CCR7 and CXCR4 compared with control cells. Melanoma cell migration in TSA- and 5-Aza-treated cells was 7- and 2-fold higher than control cells for CCR7 and CXCR4, respectively. In summary, a histone deacetylase inhibitor and a demethylating agent up-regulated CCR7 and CXCR4 expression on melanoma cells. This increase in chemokine receptor expression correlated with functional activity. Most importantly, we have identified an epigenetic mechanism that may endogenously regulate chemokine receptor expression on melanoma cells.

La recherche du ganglion sentinelle dans le mélanome malin cutané de bas stade est-elle réellement peu invasive ?

AIM

The aim of this study was to analyze outcome in patients enrolled in sentinel node biopsy procedure in early-staged cutaneous melanoma.

MATERIAL AND METHODS

Therefore a prospective study was conducted enrolling patients presenting with early-staged cutaneous melanoma. Our study focused on age and sex, duration from diagnosis to treatment, duration of hospitalization, dressing care and work inability in current follows. Duration from scintigraphy to surgery was analyzed and compared to sensibility of the procedure. What is more we observed rate and kind of complications and economical consequences, increasing duration of dressing care and work inability. The authors aimed at evaluating costs of SLN procedure including hospitalization, lymphoscintigraphy, general anaesthesia, costs of dressings, inability and overcosts of complications.

RESULTS

Forty-five patients were enrolled in our study (sex-ratio 1/2) mean aged 60 years old. Duration from diagnosis to treatment was mean 36 days. Sensibility of the procedure was excellent in trunk and limbs cases, lower in head and neck. In current cases patients were mean hospitalized three days, underwent 20 days of dressings and work inability depended on further interferon treatment. Complications occurred in 25% as seroma or local infections requiring antibiotherapy. Duration to healing was then 45 days increasing inability. Global costs of SLN procedure were significantly higher than previous wait and watch policy.

CONCLUSION

SLN biopsy is an expensive and invasive procedure with a high rate of complications. It defers melanoma treatment, only way to gain survival.