Expression profiles of melanogenesis-related genes and proteins in acquired melanocytic nevus.
We used three types of AMN to investigate the expression profiles of melanogenesis-related genes [tyrosinase, tyrosinase-related protein-1 (TRP1), dopachrome tautomerase (TRP2), Pmel-17/gp100, P-protein, and microphthalmia-associated transcription factor (MITF)], as well as tyrosinase, TRP1, Pmel-17/gp100, and MITF proteins.


RESULTS
All melanogenesis-related genes examined in the junctional type were expressed in the basal epidermal layer. In the compound and intradermal types, mRNA for tyrosinase, TRP2, and MITF was expressed in all of the AMN cells. However, the expression of TRP1, P-protein, and Pmel-17/gp100 in the compound type and TRP1 in the intradermal type became weaker in accordance with the depth of the dermis layer, as compared to those levels in the basal to upper dermis layer. Although tyrosinase and Pmel-17/gp100 mRNA in the compound and intradermal types was expressed in the intraepidermal and dermal components, immunohistochemical staining showed that tyrosinase proteins were not detected in the lower dermis layer and Pmel-17/gp100 proteins were not detected in the dermis.


CONCLUSIONS
Our results suggest that all nevus cells that constitute AMN tissue originate from melanocytes. Further, there may be differences in the transcription levels of melanogenesis-related genes as well as in their post-transcriptional regulation between nevus cells located in the basal epidermal to upper dermis layer and those in the lower dermis layer.
Hashimoto
Y
Y
The First Department of Dermatology, Toho University School of Medicine, Omori-nishi, Tokyo, Japan. yuki0729@med.toho-u.ac.jp
Ito
Y
Y
Kato
T
T
Motokawa
T
T
Katagiri
T
T
Itoh
M
M
D014408:Biomarkers, Tumor / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D052138:Genes, Neoplasm; D006801:Humans; D007124:Immunoenzyme Techniques; D017403:In Situ Hybridization; D019746:Intramolecular Oxidoreductases / Q000235:genetics / Q000378:metabolism; D008544:Melanocytes / Q000378:metabolism / Q000473:pathology; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D051739:Microphthalmia-Associated Transcription Factor / Q000235:genetics / Q000378:metabolism; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism; D009508:Nevus, Pigmented / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D012867:Skin / Q000378:metabolism / Q000473:pathology; D012878:Skin Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D058951:gp100 Melanoma Antigen
D014408:Biomarkers, Tumor; C497234:MITF protein, human; D008562:Membrane Glycoproteins; D051739:Microphthalmia-Associated Transcription Factor; D009363:Neoplasm Proteins; C548637:PMEL protein, human; D011506:Proteins; D012333:RNA, Messenger; D058951:gp100 Melanoma Antigen; D010088:Oxidoreductases; C489799:TYRP1 protein, human; D019746:Intramolecular Oxidoreductases; C042501:dopachrome isomerase