Widespread expression of parathyroid hormone-related peptide in melanocytic cells

• Published in: British journal of dermatology (1951) Vol. 148; no. 3; pp. 533 - 538
• Main Authors: Kageshita, T., Ishihara, T., Tokuo, H., Funasaka, Y., Ichihashi, M., Dong, J., Nakajima, M., Ono, T.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.03.2003; Blackwell; Oxford University Press
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Biological and medical sciences; Child; Dermatology; disease progression; Female; Humans; Immunohistochemistry - methods; Investigative techniques, diagnostic techniques (general aspects); Male; malignant melanoma; Medical sciences; Melanocytes - metabolism; Melanoma - metabolism; Middle Aged; Nevus - metabolism; parathyroid hormone-related peptide; Parathyroid Hormone-Related Protein; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Peptide Hormones - analysis; Peptide Hormones - blood; Reverse Transcriptase Polymerase Chain Reaction - methods; RNA, Messenger - analysis; Skin Neoplasms - metabolism; Tumor Cells, Cultured; Human; Cell culture; parathyroid hormone-related peptide; Melanocyte; Malignant melanoma; Parathyroid hormone related peptide; disease progression
• ISSN: 0007-0963; 1365-2133
• DOI: 10.1046/j.1365-2133.2003.05171.x

Summary Background Parathyroid hormone‐related peptide (PTH‐rP) was associated with the syndrome of hypercalcaemia of malignancy. An increased serum level of PTH‐rP could occur in patients with advanced melanoma. Objectives We examined PTH‐rP expression in cultured melanocytic cell lines and in lesions of melanocytic origin for associations with clinicopathological variables of disease progression. We measured the supernatant and cell lysate level of PTH‐rP in cultured melanoma cells to clarify whether melanoma cells secrete PTH‐rP. Methods PTH‐rP expression was examined by reverse transcriptase–polymerase chain reaction (RT–PCR) in cultured melanocytic cell lines and by immunoperoxidase staining in 18 melanocytic naevi, 40 primary melanoma and 19 metastatic melanoma lesions. The supernatant level of PTH‐rP was measured with an immunoradiometric assay. Results RT–PCR products of PTH‐rP mRNA were detected in six of eight melanoma cell lines; however, neither naevus cells nor melanocytes showed positive products. On the other hand, immunohistochemical analysis showed that PTH‐rP was widely expressed both in benign and malignant melanocytic lesions. In addition, PTH‐rP expression was not associated with any clinicopathological variables. Cell lysate but not the supernatant of melanoma cells showed high PTH‐rP levels. Conclusions These results suggest that PTH‐rP was widely expressed in melanocytic cells; however, the cells did not secrete PTH‐rP.