Expression of nuclear factor erythroid 2 protein in malignant cutaneous tumors.
BACKGROUND
Reactive oxygen species (ROS) damages cell molecules, and modifies cell signaling. The nuclear factor E2-related factor (Nrf2) is a critical transcription regulator, which protects cells against oxidative damage. Nrf2 expression is increased in a large number of cancers. However, little information has been reported regarding the expression of Nrf2 in skin cancers. Hence, we explored the expression of Nrf2 protein in skin cancers.


METHODS
The Nrf2 protein expression in 24 specimens, including 6 malignant melanomas (MM), 6 squamous cell carcinomas (SCC), 6 basal cell carcinomas (BCC), and 6 normal skin tissues, was evaluated by western blotting. Immunohistochemical staining was performed. The expression of Kelch-like ECH-associated protein 1 (Keap1), the key regulator of Nrf2, was also analyzed by western blotting.


RESULTS
Small interfering RNA transfection to the melanoma cell line G361 confirmed that an approximately 66 kDa band was the true Nrf2 band. The western blot revealed that the Nrf2 protein was definitely expressed in normal skin tissues, but the Nrf2 expression was decreased in MM, SCC, and BCC. Immunohistochemical examination showed that expression of Nrf2 was decreased in all skin cancer tissues compared to the normal skin tissues. Keap1 was not expressed in all malignant skin tumors and normal skin tissues by western blot.


CONCLUSIONS
ROS was increased in various types of cancers which proteins were highly expressed or underexpressed. This study demonstrated that the expression of Nrf2 protein was down-regulated in human malignant skin tumors. We suggest that decreased expression of Nrf2 is related to skin cancers.
Department of Plastic and Reconstructive Surgery, Soonchunhyang Gumi Hospital, Soonchunhyang University College of Medicine, Gumi, Korea.
Chang Yong
CY
Choi
Department of Plastic and Reconstructive Surgery, Soonchunhyang Gumi Hospital, Soonchunhyang University College of Medicine, Gumi, Korea.
Jin Young
JY
Kim
Department of Plastic and Reconstructive Surgery, Soonchunhyang Gumi Hospital, Soonchunhyang University College of Medicine, Gumi, Korea.
Seo Yeong
SY
Wee
Department of Plastic and Reconstructive Surgery, Hanyang University Guri Hospital, Hanyang University College of Medicine, Guri, Korea.
Jang Hyun
JH
Lee
Department of Plastic and Reconstructive Surgery, Soonchunhyang University Cheonan Hospital, Cheonan, Korea.
Doo Hyun
DH
Nam
Department of Plastic and Reconstructive Surgery, Soonchunhyang University College of Medicine, Seoul, Korea.
Chul Han
CH
Kim
Molecular Cancer Research, Soonchunhyang University College of Medicine, Cheonan, Korea.
Moon Kyun
MK
Cho
Molecular Cancer Research, Soonchunhyang University College of Medicine, Cheonan, Korea.
Yoon Jin
YJ
Lee
Molecular Cancer Research, Soonchunhyang University College of Medicine, Cheonan, Korea.
Hae Seon
HS
Nam
Molecular Cancer Research, Soonchunhyang University College of Medicine, Cheonan, Korea.
Sang Han
SH
Lee
Molecular Cancer Research, Soonchunhyang University College of Medicine, Cheonan, Korea.
Sung Woo
SW
Cho
NF-E2-related factor 2; Reactive oxygen species; Skin neoplasms