Carnosic acid, an inducer of NAD(P)H quinone oxidoreductase 1, enhances the cytotoxicity of β‑lapachone in melanoma cell lines

Abstract

Abstract. NAD(P)H quinone oxidoreductase 1 (NQO1)-dependent antitumor drugs such as β-lapachone (β-lap) are attractive candidates for cancer chemotherapy because several tumors exhibit higher expression of NQO1 than adjacent tissues. Although the association between NQO1 and β-lap has been elucidated, the effects of a NQO1-inducer and β-lap used in combination remain to be clarified. It has previously been reported that melanoma cell lines have detectable levels of NQO1 expression and are sensitive to NQO1-dependent drugs such as 17-allylamino-17-demethoxygeldanamycin. The present study was conducted to investigate the involvement of NQO1 in β-lap-mediated toxicity and the utility of combination treatment with a NQO1-inducer and β-lap in malignant melanoma cell lines. Decreased expression or inhibition of NQO1 caused these cell lines to become less sensitive to β-lap, indicating a requirement of NQO1 activity for β-lap-mediated toxicity. Of note was that carnosic acid (CA), a compound extracted from rosemary, was able to induce further expression of NQO1 through NF-E2 related factor 2 (NRF2) stabilization, thus significantly enhancing the cytotoxicity of β-lap in all of the melanoma cell lines tested. Taken together, the data presented in the current study indicated that the NRF2-NQO1 axis may have potential value as a therapeutic target in malignant melanoma to improve the rate of clinical response to NQO1-dependent antitumor drugs. IntroductionMalignant melanoma is one of the most aggressive forms of cancer, exhibiting resistance to various forms of chemotherapy.The global incidence and mortality rates of malignant melanoma are increasing (1-3). Novel targeted therapies designed to kill melanoma cells harboring mutations in B-Raf proto-oncogene, serine/threonine kinase (BRAF) have been developed using vemurafenib, which is a specific BRAF inhibitor (4,5). Missense mutations to the BRAF gene, most commonly a valine-to-glutamic acid substitution at codon 600, has been observed in ~80% of melanocytic nevi and ~50% of melanomas (6-9). In addition to this BRAF mutation, another therapeutic target has been investigated, as melanomas, including acral lentiginous melanoma, the most common type in ethnicities that produce high levels of melanin, have a low frequency of BRAF gene mutation (10,11). However, details of the mechanism responsible for the drug insensitivity of melanomas lacking BRAF mutations have been largely unclear. On the basis of the aforementioned background, a search for novel therapeutic strategies is justified.β-lapachone (β-lap), a lipophilic cytotoxic o-naphtoquinone derived from the bark of the South American Lapacho tree (Tabebuia avellanedae), has recently attracted attention as an antitumor drug (12,13). The mechanism of its antitumor effect is considered to involve the formation of reactive oxygen species (ROS) (13-15). ROS and other types of radicals are involved in a variety of biological phenomena, including tumorigenesis, degenerative disease and aging (16,17), and are also important medi...

Characterization of Phenolic Compounds and Antiproliferative Effects of Salvia pomifera and Salvia fruticosa Extracts

“…Lin et al, 2018 [43] demonstrated the antiproliferative effect of CA in combination with carmustine or lomustine in B16F10 melanoma cells and tumors arising from B16F10 cells xenografted to the back of C57BL/6 mice. Since CA induces NQO1 expression in melanoma cells in vitro, it affects the cell proliferation and sensitizes melanoma cells to other antitumor drugs [12]. Furthermore, it has been shown that CA inhibits the adhesion and migration of melanoma cells at least partially due to the inhibition of epithelial-mesenchymal transition (EMT) and AKT inactivation [16,18].…”

“…It seems that CA is not distributed evenly in plant tissues but rather is found predominantly in the aerial parts. It has also been shown that the amount of CA in plants varies based on the ontogenetic stage of the plant and the environmental conditions [12,13,14,15]. Several studies have shown that CA exhibits interesting biological effects such as anti-inflammatory and anti-oxidant activities.…”

“…In another study, CA activated the KEAP1/NRF2 axis inducing NQO1 expression. In this way, CA could enhance the toxicity of other anti-cancer drugs in melanoma treatment [12]. Melanoma is an aggressive skin cancer type that develops from melanocytes, which are responsible for melanin pigmentation.…”

Carnosic acid potentiates the anticancer effect of temozolomide by inducing apoptosis and autophagy in glioma

“…CA may also function by enhancing the antitumor effects of current chemotherapeutic agents [ 19 ]. CA enhances the cellular cytotoxicity induced by β-lapachone in melanoma [ 15 ], by tamoxifen [ 25 ] and doxorubicin [ 26 ] in breast cancer, and by adriamycin [ 27 ] and arsenic trioxide [ 28 ] in leukemia. In this study, though TMZ could inhibit glioma cell growth, TMZ in combination with low-dose CA was more effective than TMZ alone.…”

“…The CA and fisetin combination treatment led to enhanced inhibition of cell growth by inducing apoptosis in lung cancer [ 13 ]. CA enhanced carmustine, lomustine, and β-lapachone-induced cell growth inhibition and cell cycle arrest in melanoma [ 14 , 15 ]. However, the combination effects of CA and TMZ on glioma and the underlying molecular mechanism are still ambiguous.…”