Cytoplasmic phosphorylated ERK1/2 expression in patients with melanoma is associated with tumor stage and metastasis

ABSTRACT

Melanoma is the cause of most deaths from skin cancer. The extracellular signal-regulated kinase 1/2 (ERK1/2) pathway has been reported to participate in progression of melanoma in fair skinned populations. ERK1/2 is found in both the cytoplasm and nucleus of cells, and phosphorylated ERK1/2 has been implicated in tumor progression. We investigated the relation between melanoma progression and expression of cytoplasmic and nuclear phosphorylated ERK1/2. We examined 34 surgically resected melanomas and investigated their clinicopathologic characteristics. We found immunostaining of phosphorylated ERK1/2 in all melanomas and faint staining in benign nevi. We found expression of cytoplasmic phosphorylated ERK1/2 in most melanomas; however, nuclear phosphorylated ERK1/2 expression was found in only five melanomas. Expression of cytoplasmic phosphorylated ERK1/2 was related to the tumor stage in melanoma. Nine of 10 cases of distant metastasis were positive for cytoplasmic phosphorylated ERK1/2. Our findings suggest that phosphorylated ERK1/2 expression is relevant to clinical pathology and that in melanoma patients, phosphorylated ERK1/2 expression is found in both the cytoplasm and nucleus. Our findings suggest that cytoplasmic phosphorylated ERK1/2 participates in progression of melanoma and that it could be a useful target for clinical treatment of melanoma.

KEYWORDS:

• Cytoplasm
• ERK1/2
• extracellular signal-regulated kinase 1/2
• human
• immunohistochemistry
• melanoma
• phosphorylation

Acknowledgments

Yen-Shuo Tseng and Pei-Ru Wu contributed equally to this work.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was funded by the National Science Council of Taiwan [NSC 103-2314-B-038-023-MY2].