The expression of NAD(P)H:quinone oxidoreductase 1 is increased along with NF-κB p105/p50 in human cutaneous melanomas

Abstract

NAD(P)H:quinone oxidoreductase 1 (NQO1) is a key enzyme involved in metabolism of quinones and may perform multiple functions within the cell. Recent studies demonstrated that NQO1 is overexpressed in many types of tumors, including the lung, ovary, adrenal gland, thyroid, liver, colon, breast, and pancreas. To investigate whether NQO1 plays a role in melanoma pathogenesis, we used tissue microarray technology and immunohistochemistry to examine NQO1 expression in 56 dysplastic nevi and 93 primary melanoma biopsies. Our data showed that NQO1 expression is significantly increased in primary melanomas compared with dysplastic nevi (P=0.015, chi2 test). Our results also revealed that the increase of NQO1 was not associated with patient age, tumor thickness, ulceration, tumor site, American Joint Committee on Cancer (AJCC) stage, and 5-year patient survival. Interestingly, we found that female patients had more NQO1 expression than male patients (P=0.022, chi2 test). Furthermore, NQO1 expression level was significantly higher in superficial spreading melanomas compared with other tumor subtypes (P=0.020, chi2 test). Moreover, we found that NQO1 expression is significantly correlated with the expression of NF-kappaB subunit p50 (P=0.032, chi2 test). Our findings suggest that NQO1 may play an important role in the initiation stage of melanoma development.