Very interesting new study wich also confirm some theories wich suggest that melanotan-1 could prevent Skin Cancer and Melanoma:
 
 
Quoted from http://www.ncbi.nlm.nih.gov/pubmed/20067588
 
 
MC1R stimulation by alpha-MSH induces catalase and promotes its re-distribution to the cell periphery and dendrites.
Maresca V, Flori E, Bellei B, Aspite N, Kovacs D, Picardo M.
 
Laboratorio di Fisiopatologia Cutanea e Biologia Molecolare-Centro di Metabolomica, San Gallicano Dermatologic Institute IRCCS, Rome, Italy.
 
Abstract
We demonstrated a direct correlation between melanogenic and catalase activities on in vitro and ex vivo models. Here, we investigated whether the stimulation of Melanocortin-1 Receptor (MC1R) could influence catalase expression, activity and cellular localization. For this purpose, we treated B16-F0 melanoma cells with alpha-Melanocyte Stimulating Hormone (alpha-MSH) and we showed a rapid induction of catalase through a cAMP/PKA-dependent, microphthalmia-associated transcription factor (MITF) independent mechanism, acting at post-transcriptional level. Moreover, alpha-MSH promoted a partial re-distribution of catalase to the cell periphery and dendrites. This work strengthens the correlation between melanogenesis and anti-oxidants, demonstrating the induction of catalase in response to a melanogenic stimulation, such as alpha-MSH-dependent MC1R activation. Moreover, this study highlights catalase regulatory mechanisms poorly known, and attributes to alpha-MSH a protective role in defending melanocytes, and possibly keratinocytes, not only on the basis of its pigmentary action, but also for its capacity to stimulate a quick anti-oxidant defence.

At least not in vitro as shown in some experiments with alpha- msh an diffenret  of the most common melanoma cultives

Well, The in-vivo study is in this forum..... I believe it is a good prove, don´t you?
 
I understand you, and I would like to investigate more or have more studies regarding this Alpha msh but at least what we have nothing points to danger regarding Melanoma.