The NQO1 Pro187Ser polymorphism and breast cancer susceptibility: evidence from an updated meta-analysis

Impact of NQO1 dysregulation in CNS disorders

NAD(P)H Quinone Dehydrogenase 1 (NQO1) plays a pivotal role in the regulation of neuronal function and synaptic plasticity, cellular adaptation to oxidative stress, neuroinflammatory and degenerative processes, and tumorigenesis in the central nervous system (CNS). Impairment of the NQO1 activity in the CNS can result in abnormal neurotransmitter release and clearance, increased oxidative stress, and aggravated cellular injury/death. Furthermore, it can cause disturbances in neural circuit function and synaptic neurotransmission. The abnormalities of NQO1 enzyme activity have been linked to the pathophysiological mechanisms of multiple neurological disorders, including Parkinson's disease, Alzheimer's disease, epilepsy, multiple sclerosis, cerebrovascular disease, traumatic brain injury, and brain malignancy. NQO1 contributes to various dimensions of tumorigenesis and treatment response in various brain tumors. The precise mechanisms through which abnormalities in NQO1 function contribute to these neurological disorders continue to be a subject of ongoing research. Building upon the existing knowledge, the present study reviews current investigations describing the role of NQO1 dysregulations in various neurological disorders. This study emphasizes the potential of NQO1 as a biomarker in diagnostic and prognostic approaches, as well as its suitability as a target for drug development strategies in neurological disorders.

Genetic Polymorphism of NQO1 Gene is Associated with Susceptibility of Ischemic Stroke in Chinese Han Nationality

PURPOSE

NAD(P)H: Quinone Oxidoreductase 1 gene (NQO1) polymorphism is associated with the risk of cardiovascular disease. This study was designed to investigate the relationship between NQO1 gene polymorphism and ischemic stroke susceptibility in Chinese Han nationality.

PATIENTS AND METHODS

One hundred and forty-one patients diagnosed with ischemic stroke and 139 matched control groups were recruited in this study. The polymorphism distribution of rsl800566 locus and rs10517 locus of NQO1 gene was genotyped via TaqMan assay, and the concentration of Oxidized low-density lipoprotein (ox-LDL) in the blood of the subjects was detected by enzyme linked immunosorbent assay (ELISA). The relationship between the polymorphism distribution and the susceptibility to ischemic stroke was evaluated.

RESULTS

The frequency distribution of the three genotypes of NQO1 rs1800566 between the case group and the control group was statistically significant, and cases carrying CT and TT genotype were less likely to suffer from ischemic stroke. Compared with individuals carrying T allele, C allele carriers have higher risk of ischemic stroke. However, there was no significant difference in frequency distribution among the three genotypes of NQO1 rs10517 between controls and patients.

CONCLUSION

The NQO1 rs1800566 C allele may be a novel marker associated with ischemic stroke susceptibility in Chinese Han population. Polymorphism of rsl800566 locus in NQO1 gene may be protective against ischemic stroke risk.

ROS‑associated mechanism of different concentrations of pinacidil postconditioning in the rat cardiac Nrf2‑ARE signaling pathway

Previous studies have confirmed that 50 µmol/l pinacidil postconditioning (PPC) activates the nuclear factor-E2 related factor 2 (Nrf2)-antioxidant responsive element (ARE) pathway, which protects the myocardium from ischemia-reperfusion (IR) injury; however, whether this is associated with reactive oxygen species (ROS) generation remains unclear. In the present study, a Langendorff rat model of isolated myocardial IR was established to investigate the mechanism of PPC at different concentrations, as well as the association between the rat myocardial Nrf2-ARE signaling pathway and ROS. A total of 48 rats were randomly divided into the following six groups (n=8 per group): i) Normal; ii) IR iii) 10 µmol/l PPC (P10); iv) 30 µmol/l PPC (P30); v) 50 µmol/l PPC (P50); and vi) N-(2-mercaptopropionyl)-glycine (MPG; a ROS scavenger) + 50 µmol/l pinacidil (P50 + MPG). At the end of reperfusion (T3), compared with the IR group, the P10, P30 and P50 groups exhibited improved cardiac function, such as left ventricular development pressure, heart rate, left ventricular end-diastolic pressure, +dp/dtmax, myocardial cell ultrastructure and mitochondrial Flameng score. Furthermore, the P10 and P50 groups demonstrated the weakest and most marked improvements, respectively. Additionally, in the P10, P30 and P50 groups, the residual ROS content at the end of reperfusion was highly negatively correlated with relative expression levels of Nrf2 gene and protein. Higher pinacidil concentration was associated with higher ROS generation at 5 min post-reperfusion (T2), although this was significantly lower compared with the IR group, as well as with increased expression levels of antioxidant proteins and phase II detoxification enzymes downstream of the Nrf2 and Nrf2-ARE pathways. This result was associated with a stronger ability to scavenge ROS during reperfusion, leading to lower levels of ROS at the end of reperfusion (T3) and less myocardial damage. The optimal myocardial protective effect was achieved by 50 mmol/l pinacidil. However, cardiac function of the P50 + MPG group was significantly decreased, ultrastructure of cardiomyocytes was significantly impaired and the relative expression levels of genes and proteins in the Nrf2-ARE pathway were decreased. The aforementioned results confirmed that different PPC concentrations promoted early generation of ROS and activated the Nrf2-ARE signaling pathway following reperfusion, regulated expression levels of downstream antioxidant proteins and alleviated myocardial IR injury in rats. Treatment with 50 mmol/l pinacidil resulted in the best myocardial protection.

Impact of xenobiotic-metabolizing gene polymorphisms on breast cancer risk in South Indian women

BACKGROUND

Functional variants of the xenobiotic-metabolizing genes (XMG) might modulate breast cancer (BC) risk by altering the rate of metabolism and clearance of myriad types of potent carcinogens from the breast tissue. Despite mounting evidence on the role of XMG variants on BC risk, the current knowledge regarding their influence on BC development is still fragmentary.

METHODS

The present study examined the candidate genetic variants in CYP1A1, NQO1, GST-T1, GST-M1, and GST-P1 in 1002 subjects (502 BC patients and 500 disease-free women). PCR-RFLP was employed to genotype the mono-nucleotide variation in CYP1A1, NQO1, and GST-P1, and allele-specific PCR was used to detect the deletion polymorphism in GST-T1 and GST-M1 genes.

RESULTS

Regarding CYP1A1-M1 polymorphism, the heterozygous TC and mutant CC genotype conferred 1.47-fold (95% CI 1.13-1.91, p = 0.004) and 1.84-fold (95% CI 1.17-2.91, p = 0.009) elevated risk of BC. GST-T1 null genotype was associated with increased BC risk (OR 1.47; 95% CI 1.02-2.11, p = 0.037). For the NQO1 C609T variant, the mutant T allele was associated with BC risk with an odds ratio of 1.22 (95% CI 1.02-1.48, p = 0.034). Combinatorial analysis indicated that the presence of NQO1*2 (CT), CYP1A1-M1 (CC), and GST-P1 rs1695 (AG) genotypes conferred 16.7-fold elevated risk of BC (95% CI 3.65-76.85; p < 0.001). Moreover, GST-M1 null genotype was associated with the development of larger primary breast tumors.

CONCLUSION

Xenobiotic-metabolizing gene polymorphisms may play a crucial role in mammary carcinogenesis in South Indian women.

Individual and combined effects of GSTM1 and GSTT1 polymorphisms on colorectal cancer risk: an updated meta-analysis

BACKGROUND

The presence or absence of glutathione S-transferase M1 gene (GSTM1) and glutathione S-transferase T1 gene (GSTT1) polymorphisms, and their combined effects have been suggested as a risk factor for colorectal cancer (CRC). However, the results are inconsistent.

OBJECTIVES

An updated meta-analysis was performed to solve the controversy.

METHODS

Meta-analyses of Observational Studies in Epidemiology (MOOSE) guidelines were used.

RESULTS

Overall, the GSTM1 null genotype was associated with an increased CRC risk in Caucasians (odds ratio (OR) = 1.14, 95% confidence interval (CI): 1.05-1.23), Asians (OR = 1.19, 95% CI: 1.08-1.32), high-quality studies (OR = 1.12, 95% CI: 1.06-1.18). Moreover, the GSTM1 null genotype was also associated with an increased colon cancer risk (OR = 1.32, 95% CI: 1.16-1.51). The GSTT1 null genotype was also associated with an increased CRC risk in Asians (OR = 1.08, 95% CI: 1.02-1.15) and Caucasians (OR = 1.24, 95% CI: 1.09-1.41). Moreover, The GSTT1 null genotype was associated with an increased rectal cancer risk (OR = 1.13, 95% CI: 1.01-1.27, I2 = 8.3%) in subgroup analysis by tumor location. Last, the GSTM1 null/GSTT1 null genotype was associated with an increased CRC risk in Asians.

CONCLUSION

This meta-analysis indicates that the GSTM1 and GSTT1 null genotypes are associated with increased CRC risk in Asians and Caucasians, and the GSTM1 null/GSTT1 null genotype was associated with increased CRC risk in Asians.

Insights into the New Cancer Therapy through Redox Homeostasis and Metabolic Shifts

Modest levels of reactive oxygen species (ROS) are necessary for intracellular signaling, cell division, and enzyme activation. These ROS are later eliminated by the body’s antioxidant defense system. High amounts of ROS cause carcinogenesis by altering the signaling pathways associated with metabolism, proliferation, metastasis, and cell survival. Cancer cells exhibit enhanced ATP production and high ROS levels, which allow them to maintain elevated proliferation through metabolic reprograming. In order to prevent further ROS generation, cancer cells rely on more glycolysis to produce ATP and on the pentose phosphate pathway to provide NADPH. Pro-oxidant therapy can induce more ROS generation beyond the physiologic thresholds in cancer cells. Alternatively, antioxidant therapy can protect normal cells by activating cell survival signaling cascades, such as the nuclear factor erythroid 2-related factor 2 (Nrf2)-Kelch-like ECH-associated protein 1 (Keap1) pathway, in response to radio- and chemotherapeutic drugs. Nrf2 is a key regulator that protects cells from oxidative stress. Under normal conditions, Nrf2 is tightly bound to Keap1 and is ubiquitinated and degraded by the proteasome. However, under oxidative stress, or when treated with Nrf2 activators, Nrf2 is liberated from the Nrf2-Keap1 complex, translocated into the nucleus, and bound to the antioxidant response element in association with other factors. This cascade results in the expression of detoxifying enzymes, including NADH-quinone oxidoreductase 1 (NQO1) and heme oxygenase 1. NQO1 and cytochrome b5 reductase can neutralize ROS in the plasma membrane and induce a high NAD⁺/NADH ratio, which then activates SIRT1 and mitochondrial bioenergetics. NQO1 can also stabilize the tumor suppressor p53. Given their roles in cancer pathogenesis, redox homeostasis and the metabolic shift from glycolysis to oxidative phosphorylation (through activation of Nrf2 and NQO1) seem to be good targets for cancer therapy. Therefore, Nrf2 modulation and NQO1 stimulation could be important therapeutic targets for cancer prevention and treatment.

Inherited alterations of TGF beta signaling components in Appalachian cervical cancers

PURPOSE

This study examined targeted genomic variants of transforming growth factor beta (TGFB) signaling in Appalachian women. Appalachian women with cervical cancer were compared to healthy Appalachian counterparts to determine whether these polymorphic alleles were over-represented within this high-risk cancer population, and whether lifestyle or environmental factors modified the aggregate genetic risk in these Appalachian women.

METHODS

Appalachian women's survey data and blood samples from the Community Awareness, Resources, and Education (CARE) CARE I and CARE II studies (n = 163 invasive cervical cancer cases, 842 controls) were used to assess gene-environment interactions and cancer risk. Polymorphic allele frequencies and socio-behavioral demographic measurements were compared using t tests and χ2 tests. Multivariable logistic regression was used to evaluate interaction effects between genomic variance and demographic, behavioral, and environmental characteristics.

RESULTS

Several alleles demonstrated significant interaction with smoking (TP53 rs1042522, TGFB1 rs1800469), alcohol consumption (NQO1 rs1800566), and sexual intercourse before the age of 18 (TGFBR1 rs11466445, TGFBR1 rs7034462, TGFBR1 rs11568785). Interestingly, we noted a significant interaction between "Appalachian self-identity" variables and NQO1 rs1800566. Multivariable logistic regression of cancer status in an over-dominant TGFB1 rs1800469/TGFBR1 rs11568785 model demonstrated a 3.03-fold reduction in cervical cancer odds. Similar decreased odds (2.78-fold) were observed in an over-dominant TGFB1 rs1800469/TGFBR1 rs7034462 model in subjects who had no sexual intercourse before age 18.

CONCLUSIONS

This study reports novel associations between common low-penetrance alleles in the TGFB signaling cascade and modified risk of cervical cancer in Appalachian women. Furthermore, our unexpected findings associating Appalachian identity and NQO1 rs1800566 suggests that the complex environmental exposures that contribute to Appalachian self-identity in Appalachian cervical cancer patients represent an emerging avenue of scientific exploration.

Dissecting the prevention of estrogen-dependent breast carcinogenesis through Nrf2-dependent and independent mechanisms

Breast cancer is the most common malignancy among women worldwide. Various studies indicate that prolonged exposure to elevated levels of estrogens is associated with development of breast cancer. Both estrogen receptor-dependent and independent mechanisms can contribute to the carcinogenic effects of estrogens. Among them, the oxidative metabolism of estrogens plays a key role in the initiation of estradiol-induced breast cancer by generation of reactive estrogen quinones as well as the associated formation of oxygen free radicals. These genotoxic metabolites can react with DNA to form unstable DNA adducts which generate mutations leading to the initiation of breast cancer. A variety of endogenous and exogenous factors can alter estrogen homeostasis and generate genotoxic metabolites. The use of specific phytochemicals and dietary supplements can inhibit the risk of breast cancer not only by the modulation of several estrogen-activating enzymes (CYP19, CYP1B1) but also through the induction of various cytoprotective enzymes (eg, SOD3, NQO1, glutathione S-transferases, OGG-1, catechol-O-methyltransferases, CYP1B1A, etc.) that reestablish the homeostatic balance of estrogen metabolism via nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent and independent mechanisms.

Possible association of HMOX1 and NQO1 polymorphisms with anti-tuberculosis drug-induced liver injury: A matched case-control study

WHAT IS KNOWN AND OBJECTIVE

Reactive metabolites from anti-tuberculosis (anti-TB) drugs can result in abnormal accumulation of reactive oxygen species (ROS), which plays an important role in anti-TB drug-induced liver injury (ATLI). Liver cells could keep the production of ROS in balance by antioxidant activities. The heme oxygenase 1, encoded by the HMOX1 gene and NADH:quinone oxidoreductase 1, encoded by the NQO1 gene are crucial mediators of cellular defense against ROS. The present study aimed to investigate the associations between HMOX1 and NQO1 polymorphisms and ATLI in Chinese anti-TB treatment population.

METHODS

A matched case-control study was conducted using 314 ATLI cases and 628 controls. Multivariate conditional logistic regression analysis was used to estimate the association between genotypes and risk of ATLI by the odds ratios (ORs) with 95% confidence intervals (CIs), with weight and use of hepatoprotectant as covariates.

RESULTS AND DISCUSSION

Patients carrying the GG genotype at rs2071748 in HMOX1 were at a higher risk of ATLI than those with the AA genotype (adjusted OR = 1.503, 95% CI: 1.005-2.249, P = 0.047), and significant differences were also found under the recessive (P = 0.015) and additive (P = 0.045) models. Subgroup analysis confirmed the relationship in mild hepatotoxicity cases under the recessive and additive models (adjusted OR = 1.714, 95% CI: 1.169-2.513, P = 0.006; adjusted OR = 1.287, 95% CI: 1.015-1.631, P = 0.037, respectively).

WHAT IS NEW AND CONCLUSION

This is the first study to explore the relationship between HMOX1, NQO1 polymorphisms and ATLI in Chinese anti-TB treatment population. Based on a matched case-control study, genetic polymorphisms of HMOX1 may be associated with susceptibility to ATLI in the Chinese population.

Electromagnetic Field Could Protect SH-SY5Y Cells Against Cisplatin Cytotoxicity, But Not MCF-7 Cells

Cisplatin [cis-dichlorodiammine platinum (II), CDDP], morphine (Mor), and electromagnetic field (EMF) induced oxidative stress. In this study, we tried to increase the cytotoxicity of CDDP in combination with Mor and/or EMF in MCF-7 and SH-SY5Y cells. Furthermore, we evaluate the expression levels of 11 antioxidant genes in both cell lines. We designed four treatments: CDDP alone, "CDDP+Mor," "CDDP+EMF," and "CDDP+Mor+EMF." Serial dilutions of CDDP, Mor (5.0 μM), and EMF (50 Hz, 0.50 mT, "15 min field-on/15 min field-off") were used for estimation of relative IC₅₀ values. The mRNA expression levels of antioxidant genes were determined by real-time PCR. The IC₅₀ value of CDDP in "CDDP+Mor+EMF" treatment was significantly higher than CDDP alone and "CDDP+Mor" treatments in both cell lines. Whereas the expression levels of antioxidant genes in the four treatments showed similar patterns in MCF-7 cells, in SH-SY5Y cells, most of the antioxidant genes showed an upregulation with "CDDP+EMF" and "CDDP+Mor+EMF" treatments. Moreover, significant differences in the number of upregulated genes were observed between different treatments in SH-SY5Y cells. The molecular mechanism of CDDP-reduced cytotoxicity in our designed combinations is probably different in MCF-7 and SH-SY5Y cells. CDDP in combination with EMF could protect SH-SY5Y cells from the cytotoxicity, whereas it has no significant change in MCF-7 cells.

Genomic and transcriptomic profiling of resistant CEM/ADR-5000 and sensitive CCRF-CEM leukaemia cells for unravelling the full complexity of multi-factorial multidrug resistance

We systematically characterised multifactorial multidrug resistance (MDR) in CEM/ADR5000 cells, a doxorubicin-resistant sub-line derived from drug-sensitive, parental CCRF-CEM cells developed in vitro. RNA sequencing and network analyses (Ingenuity Pathway Analysis) were performed. Chromosomal aberrations were identified by array-comparative genomic hybridisation (aCGH) and multicolour fluorescence in situ hybridisation (mFISH). Fifteen ATP-binding cassette transporters and numerous new genes were overexpressed in CEM/ADR5000 cells. The basic karyotype in CCRF-CEM cells consisted of 47, XX, der(5)t(5;14) (q35.33;q32.3), del(9) (p14.1), +20. CEM/ADR5000 cells acquired additional aberrations, including X-chromosome loss, 4q and 14q deletion, chromosome 7 inversion, balanced and unbalanced two and three way translocations: t(3;10), der(3)t(3;13), der(5)t(18;5;14), t(10;16), der(18)t(7;18), der(18)t(21;18;5), der(21;21;18;5) and der(22)t(9;22). CCRF-CEM consisted of two and CEM/ADR5000 of five major sub-clones, indicating genetic tumor heterogeneity. Loss of 3q27.1 in CEM/ADR5000 caused down-regulation of ABCC5 and ABCF3 expression, Xq28 loss down-regulated ABCD1 expression. ABCB1, the most well-known MDR gene, was 448-fold up-regulated due to 7q21.12 amplification. In addition to well-known drug resistance genes, numerous novel genes and genomic aberrations were identified. Transcriptomics and genetics in CEM/AD5000 cells unravelled a range of MDR mechanisms, which is much more complex than estimated thus far. This may have important implications for future treatment strategies.

Correlation between NAD(P)H: quinone oxidoreductase 1 C609T polymorphism and increased risk of esophageal cancer: evidence from a meta-analysis

NAD(P)H: quinone oxidoreductase 1 (NQO1) C609T gene polymorphisms have been reported to influence the risk for esophageal cancer (EC) in many studies. However, the results remain controversial and ambiguous. We performed a meta-analysis, which included 13 independent studies with a total of 2357 subjects, to examine the association between NQO1 C609T polymorphism and EC. The association was assessed by five different gene models. The overall analysis suggested that the variant allele and genotypes were significantly related to increased risk of EC (odds ratio [OR] T versus C = 1.15, 95% confidence interval [CI] 0.95-1.40, probability of rejection [POR] = 0.014; OR TT versus CC = 1.32, 95% CI 1.01-1.73, POR = 0.045; OR TC versus CC = 1.32, 95% CI 0.98-1.21, POR = 0.128; OR TT + TC versus CC = 1.10, 95% CI 1.00-1.20, POR = 0.05; OR TT versus CC + TC = 1.26, 95% CI 0.95-1.57, POR = 0.103). Sensitivity analysis confirmed the reliability of these findings. Our study shows that individuals carrying the NQO1 C609T variant allele and genotypes are more susceptible to EC.

Novel non invasive diagnostic strategies in bladder cancer

Bladder cancer is one of the most commonly diagnosed malignancies worldwide, derived from the urothelium of the urinary bladder and defined by long asymptomatic and atypical clinical picture. Its complex etiopathogenesis is dependent on numerous risk factors that can be divided into three distinct categories: genetic and molecular abnormalities, chemical or environmental exposure and previous genitourinary disorders and family history of different malignancies. Various genetic polymorphisms and microRNA might represent useful diagnostic or prognostic biomarkers. Genetic and molecular abnormalities - risk factors are represented by miRNA or genetic polymorphisms proved to be part of bladder carcinogenesis such as: genetic mutations of oncogenes TP53, Ras, Rb1 or p21 oncoproteins, cyclin D or genetic polymorhisms of XPD,ERCC1, CYP1B1, NQO1C609T, MDM2SNP309, CHEK2, ERCC6, NRF2, NQO1Pro187Ser polymorphism and microRNA (miR-143, −145, −222, −210, −10b, 576-3p). The aim of our article is to highlight the most recent acquisitions via molecular biomarkers (miRNAs and genetic polymorphisms) involved in bladder cancer in order to provide early diagnosis, precise therapy according to the molecular profile of bladder tumors, as well as to improve clinical outcome, survival rates and life quality of oncological patients. These molecular biomarkers play a key role in bladder carcinogenesis, clinical evolution, prognosis and therapeutic response and explain the molecular mechanisms involved in bladder carcinogenesis; they can also be selected as therapeutic targets in developing novel therapeutic strategies in bladder malignancies. Moreover, the purpose in defining these molecular non invasive biomarkers is also to develop non invasive screening programs in bladder malignancies with the result of decreasing bladder cancer incidence in risk population.

Implications of NQO1 in cancer therapy

NAD(P)H

quinone oxidoreductase (NQO1), an obligatory two-electron reductase, is a ubiquitous cytosolic enzyme that catalyzes the reduction of quinone substrates. The NQO1- mediated two-electron reduction of quinones can be either chemoprotection/detoxification or a chemotherapeutic response, depending on the target quinones. When toxic quinones are reduced by NQO1, they are conjugated with glutathione or glucuronic acid and excreted from the cells. Based on this protective effect of NQO1, the use of dietary compounds to induce the expression of NQO1 has emerged as a promising strategy for cancer prevention. On the other hand, NQO1-mediated two-electron reduction converts certain quinone compounds (such as mitomycin C, E09, RH1 and -lapachone) to cytotoxic agents, leading to cell death. It has been known that NQO1 is expressed at high levels in numerous human cancers, including breast, colon, cervix, lung, and pancreas, as compared with normal tissues. This implies that tumors can be preferentially damaged relative to normal tissue by cytotoxic quinone drugs. Importantly, NQO1 has been shown to stabilize many proteins, including p53 and p33ING1b, by inhibiting their proteasomal degradation. This review will summarize the biological roles of NQO1 in cancer, with emphasis on recent findings and the potential of NQO1 as a therapeutic target for the cancer therapy.

Deoxynyboquinones as NQO1-Activated Cancer Therapeutics

One of the major goals of cancer therapy is the selective targeting of cancer cells over normal cells. Unfortunately, even with recent advances, the majority of chemotherapeutics still indiscriminately kill all rapidly dividing cells. Although these drugs are effective in certain settings, their inability to specifically target cancer results in significant dose-limiting toxicities. One way to avoid such toxicities is to target an aspect of the cancer cell that is not shared by normal cells. A potential cancer-specific target is the enzyme NAD(P)H quinone oxidoreductase 1 (NQO1). NQO1 is a 2-electron reductase responsible for the detoxification of quinones. Its expression is typically quite low in normal tissue, but it has been found to be greatly overexpressed in many types of solid tumors, including lung, breast, pancreatic, and colon cancers. This overexpression is thought to be in response to the higher oxidative stress of the cancer cell, and it is possible that NQO1 contributes to tumor progression. The overexpression of NQO1 and its correlation with poor patient outcome make it an intriguing target. Although some have explored inhibiting NQO1 as an anticancer strategy, this has generally been unsuccessful. A more promising strategy is to utilize NQO1 substrates that are activated upon reduction by NQO1. For example, in principle, reduction of a quinone can result in a hydroquinone that is a DNA alkylator, protein inhibitor, or reduction-oxidation cycler. Although there are many proposed NQO1 substrates, head-to-head assays reveal only two classes of compounds that convincingly induce cancer cell death through NQO1-mediated activation. In this Account, we describe the discovery and development of one of these compounds, the natural product deoxynyboquinone (DNQ), an excellent NQO1 substrate and anticancer agent. A modular synthesis of DNQ was developed that enabled access to the large compound quantities needed to conduct extensive mechanistic evaluations and animal experiments. During these evaluations, we found that DNQ is an outstanding NQO1 substrate that is processed much more efficiently than other putative NQO1 substrates. Importantly, its anticancer activity is strictly dependent on the overexpression of active NQO1. Using previous crystal structures of NQO1, novel DNQ derivatives were designed that are also excellent NQO1 substrates and possess properties that make them more attractive than the parent natural product for translational development. Given their selectivity, potency, outstanding pharmacokinetic properties, and the ready availability of diagnostics to assess NQO1 in patients, DNQ and its derivatives have considerable potential as personalized medicines for the treatment of cancer.