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 i...
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.
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.
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대상 데이터
The Institutional Review Board of Hanyang University Hospital reviewed and approved this research protocol involving the use of tissue samples. For the study, a total of 6 normal skin tissues and 18 malignant skin tumor tissues including 6 malignant melanomas (MM), 6 squamous cell carcinomas (SCC), and 6 basal cell carcinomas (BCC) were obtained from patients who underwent excisional surgery between July 2009 and December 2011 at the Department of Plastic Surgery of the Hanyang University Guri Hospital in Korea (Table 1). The specimens were immediately frozen in liquid nitrogen after excision, and stored at -80℃.
The human malignant melanoma cell line G361 (CRL 1424, Rockville, MD, USA) was obtained from the American Type Culture Collection. The cells were cultured in Dulbecco’s Modified Eagle’s Medium (DMEM) containing 10% fetal calf serum, 100 U/mL penicillin, 100 mg/mL streptomycin at 37℃, 5% CO2.
The stored, paraffin-embedded specimens, including 6 MM, 6 SCC, and 6 BCC were used. Paraffin samples were deparaffinized in xylene, rehydrated in 10 mM citrate buffer (pH 6.
데이터처리
The data from the Raytest TINA software were analyzed using the nonparametric Mann-Whitney U test. A P < 0.
이론/모형
The relative protein expression using western blotting was plotted in a graph. The relative protein expression of Nrf2 according to the Mann-Whitney U test was analyzed. The median score of Nrf2 was found to be 0.
후속연구
We also demonstrated that skin cancers and normal skin tissues did not express the Keap1 protein. Further studies are needed to better understand the mechanism of signal transduction and regulation of Nrf2 in skin cancers.
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