Melanogenesis substrate, N‐propionyl‐cysteaminylphenol (NPrCAP), is selectively incorporated into melanoma cells and inhibits their growth by producing cytotoxic free radicals. Magnetite nanoparticles also disintegrate cancer cells and generate heat shock protein (HSP) upon exposure to an alternating magnetic field (AMF). This study tested if a chemo‐thermo‐immunotherapy (CTI therapy) strategy can be developed for better management of melanoma by conjugating NPrCAP on the surface of magnetite nanoparticles (NPrCAP/M). We examined the feasibility of this approach in B16 mouse melanoma and evaluated the impact of exposure temperature, frequency, and interval on the inhibition of re‐challenged melanoma growth. The therapeutic protocol against the primary transplanted tumor with or without AMF exposure once a day every other day for a total of three treatments not only inhibited the growth of the primary transplant but also prevented the growth of the secondary, re‐challenge transplant. The heat‐generated therapeutic effect was more significant at a temperature of 43^∘C than either 41^∘C or 46^∘C. NPrCAP/M with AMF exposure, instead of control magnetite alone or without AMF exposure, resulted in the most significant growth inhibition of the re‐challenge tumor and increased the life span of the mice. HSP70 production was greatest at 43^∘C compared to that with 41^∘C or 46^∘C. CD8⁺T cells were infiltrated at the site of the re‐challenge melanoma transplant.

Melanogenesis substrate, N‐propionyl‐4‐S‐cysteaminylphenol (NPrCAP) is specifically taken up by melanoma cells and inhibits their growth by producing cytotxic free radicals. By taking advantage of this unique chemical agent, we have established melanoma‐targeting intracellular hyperthermia by conjugating NPrCAP with magnetite nanoparticles (NPrCAP/M) upon exposure to an alternating magnetic field (AMF). This treatment causes cytotoxic reaction as well as heat shock responses, leading to elicitation of antitumor immune response, which was proved by tumor rechallenge test and CTL induction. We found the level of heat shock protein 72 (Hsp72) to be increased in the cell lysate and culture supernatant after intracellular hyperthermia. Melanoma‐specific CD8⁺ T‐cell response to dendritic cells loaded with hyperthermia‐treated tumor lysate was enhanced when compared with non‐treated tumor lysate. When heat shock protein, particularly Hsp72, was immuno‐depleted from hyperthermia‐treated tumor cell lysate, specific CD8⁺ T‐cell response was abolished. Thus, it is suggested that antitumor immune response induced by hyperthermia using NPrCAP/M is derived from the release of HSP‐peptide complex from degraded tumor cells. Therefore, this chemo‐thermo‐immuno (CTI)‐therapy might be effective not only for primary melanoma but also for distant metastasis because of induction of systemic antimelanoma immune responses. (Cancer Sci 2010)

Key Clinical Message: In reticular erythematous mucinosis, (1) the presence of dotted vessels and (2) uniform, structureless, yellowish‐white spots, and patches on dermoscopy correspond to histopathological findings of (1) vessels at the tips of the dermal papillae and (2) thickening and rupture of the collagen and fiber bundles with mucin deposition, respectively. Reticular erythematous mucinosis is a rare form of skin mucinosis that primarily affects middle‐aged women, typically appearing as papules and plaques in the upper chest or midline of the back. Here, we report the case of a 75‐year‐old woman with skin papules and plaques left untreated for 8 years. A gross skin examination was followed by histopathological and dermoscopic examinations. The main dermoscopic findings were (1) dotted vessels and (2) uniform structureless yellowish‐white spots and patches. The corresponding histopathological findings were (1) vessels at the tips of the dermal papillae and (2) thickening and rupturing of the collagen and fiber bundles with mucin deposition, respectively. Laboratory investigations revealed normal results, ruling out various autoimmune disorders. REM was diagnosed based on these findings. The study presents relevant evidence‐based findings in dermatology and cutaneous pathology as it is the first description of REM using dermoscopy. Dermoscopic diagnosis without other unnecessary tests would benefit both the clinician and the patient.