APE1/Ref-1 Role in Redox Signaling: Translational Applications of Targeting the Redox Function of the DNA Repair/Redox Protein APE1/Ref-1

The heterogeneity of most cancers diminishes the treatment effectiveness of many cancer-killing regimens. Thus, treatments that hold the most promise are ones that block multiple signaling pathways essential to cancer survival. One of the most promising proteins in that regard is APE1, whose reduction-oxidation activity influences multiple cancer survival mechanisms, including growth, proliferation, metastasis, angiogenesis, and stress responses. With the continued research using APE1 redox specific inhibitors alone or coupled with developing APE1 DNA repair inhibitors it will now be possible to further delineate the role of APE1 redox, repair and protein-protein interactions. Previously, use of siRNA or over expression approaches, while valuable, do not give a clear picture of the two major functions of APE1 since both techniques severely alter the cellular milieu. Additionally, use of the redox-specific APE1 inhibitor, APX3330, now makes it possible to study how inhibition of APE1’s redox signaling can affect multiple tumor pathways and can potentiate the effectiveness of existing cancer regimens. Because APE1 is an upstream effector of VEGF, as well as other molecules that relate to angiogenesis and the tumor microenvironment, it is also being studied as a possible treatment for age-related macular degeneration and diabetic retinopathy. This paper reviews all of APE1’s functions, while heavily focusing on its redox activities. It also discusses APE1’s altered expression in many cancers and the therapeutic potential of selective inhibition of redox regulation, which is the subject of intense preclinical studies

Development in the Gulf of Maine: Avoiding Geohazards and Embracing Opportunities

Mapping for marine-spatial planning is crucial if Maine is to safely develop its offshore resources, espe­cially wind and tidal energy. The authors focus on shallow natural gas (methane) deposits, an important and widespread geohazard in Maine’s seafloor. They describe the origin, occur­rence, and identification of natural gas in Maine’s seafloor; explain the hazards associated with these deposits and how to map them; and discuss what Maine can learn from European nations that have already developed their offshore wind resources. Because the U.S. gives states a central role in coastal management, Maine has the chance to be proactive in delineating coastal resources and demarcating potential seafloor hazards

APE1/Ref-1 knockdown in pancreatic ductal adenocarcinoma – characterizing gene expression changes and identifying novel pathways using single-cell RNA sequencing

Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1 or APE1) is a multifunctional protein that regulates numerous transcription factors associated with cancer-related pathways. Because APE1 is essential for cell viability, generation of APE1-knockout cell lines and determining a comprehensive list of genes regulated by APE1 has not been possible. To circumvent this challenge, we utilized single-cell RNA sequencing to identify differentially expressed genes (DEGs) in relation to APE1 protein levels within the cell. Using a straightforward yet novel statistical design, we identified 2837 genes whose expression is significantly changed following APE1 knockdown. Using this gene expression profile, we identified multiple new pathways not previously linked to APE1, including the EIF2 signaling and mechanistic target of Rapamycin pathways and a number of mitochondrial-related pathways. We demonstrate that APE1 has an effect on modifying gene expression up to a threshold of APE1 expression, demonstrating that it is not necessary to completely knockout APE1 in cells to accurately study APE1 function. We validated the findings using a selection of the DEGs along with siRNA knockdown and qRT-PCR. Testing additional patient-derived pancreatic cancer cells reveals particular genes (ITGA1, TNFAIP2, COMMD7, RAB3D) that respond to APE1 knockdown similarly across all the cell lines. Furthermore, we verified that the redox function of APE1 was responsible for driving gene expression of mitochondrial genes such as PRDX5 and genes that are important for proliferation such as SIPA1 and RAB3D by treating with APE1 redox-specific inhibitor, APX3330. Our study identifies several novel genes and pathways affected by APE1, as well as tumor subtype specificity. These findings will allow for hypothesis-driven approaches to generate combination therapies using, for example, APE1 inhibitor APX3330 with other approved FDA drugs in an innovative manner for pancreatic and other cancer treatments

Ref-1/APE1 as Transcriptional Regulator and Novel Therapeutic Target in Pediatric T-cell Leukemia

The increasing characterization of childhood acute lymphoblastic leukemia (ALL) has led to the identification of multiple molecular targets, but have yet to translate into more effective targeted therapies, particularly for high-risk, relapsed T-cell ALL. Searching for master regulators controlling multiple signaling pathways in T-ALL, we investigated the multi-functional protein redox factor-1 (Ref-1/APE1), which acts as a signaling "node" by exerting redox regulatory control of transcription factors important in leukemia. Leukemia patients' transcriptome databases showed increased expression in T-ALL of Ref-1 and other genes of the Ref-1/SET interactome. Validation studies demonstrated that Ref-1 is expressed in high-risk leukemia T-cells, including in patient biopsies. Ref-1 redox function is active in leukemia T-cells, regulating the Ref-1 target NF-kB, and inhibited by the redox-selective Ref-1 inhibitor E3330. Ref-1 expression is not regulated by Notch signaling, but is upregulated by glucocorticoid treatment. E3330 disrupted Ref-1 redox activity in functional studies and resulted in marked inhibition of leukemia cell viability, including T-ALL lines representing different genotypes and risk groups. Potent leukemia cell inhibition was seen in primary cells from ALL patients, relapsed and glucocorticoid-resistant T-ALL cells, and cells from a murine model of Notch-induced leukemia. Ref-1 redox inhibition triggered leukemia cell apoptosis and down-regulation of survival genes regulated by Ref-1 targets. For the first time, this work identifies Ref-1 as a novel molecular effector in T-ALL and demonstrates that Ref-1 redox inhibition results in potent inhibition of leukemia T-cells, including relapsed T-ALL. These data also support E3330 as a specific Ref-1 small molecule inhibitor for leukemia

Mental and substance use disorders from early adolescence to young adulthood among indigenous young people: final diagnostic results from an 8-year panel study

Objective—Our objective was to investigate change in prevalence rates for mental and substance abuse disorders between early adolescence and young adulthood in a cohort of indigenous adolescents who participated in an 8-year panel study. Method—The data are from a lagged, sequential study of 671 indigenous adolescents (Wave 1) from a single culture in the Northern Midwest USA and Canada. At Wave 1 (mean age 11.3 years, Wave 4 (mean age 14.3 years), Wave 6 (mean age 16.2 years), and at Wave 8 (mean age 18.3 years) the tribally enrolled adolescents completed a computer-assisted personal interview that included DISC-R assessment for 11 diagnoses. Our yearly retention rates by diagnostic wave were: Wave 2, 94.7 %; Wave 4, 87.7 %; Wave 6, 88.0 %; Wave 8, 78.5 %. Results—The findings show a dramatic increase in lifetime prevalence rates for substance use disorders. By young adulthood, over half had met criteria of substance abuse or dependence disorder. Also at young adulthood, 58.2 % had met lifetime criteria of a single substance use or mental disorder and 37.2 % for two or more substance use or mental disorders. The results are compared to other indigenous diagnostic studies and to the general population. Conclusions—A mental health crisis exists within the indigenous populations that participated in this study. Innovations within current mental health service systems are needed to address the unmet demand of adolescents and families

Mental and substance use disorders from early adolescence to young adulthood among indigenous young people: final diagnostic results from an 8-year panel study

Objective—Our objective was to investigate change in prevalence rates for mental and substance abuse disorders between early adolescence and young adulthood in a cohort of indigenous adolescents who participated in an 8-year panel study. Method—The data are from a lagged, sequential study of 671 indigenous adolescents (Wave 1) from a single culture in the Northern Midwest USA and Canada. At Wave 1 (mean age 11.3 years, Wave 4 (mean age 14.3 years), Wave 6 (mean age 16.2 years), and at Wave 8 (mean age 18.3 years) the tribally enrolled adolescents completed a computer-assisted personal interview that included DISC-R assessment for 11 diagnoses. Our yearly retention rates by diagnostic wave were: Wave 2, 94.7 %; Wave 4, 87.7 %; Wave 6, 88.0 %; Wave 8, 78.5 %. Results—The findings show a dramatic increase in lifetime prevalence rates for substance use disorders. By young adulthood, over half had met criteria of substance abuse or dependence disorder. Also at young adulthood, 58.2 % had met lifetime criteria of a single substance use or mental disorder and 37.2 % for two or more substance use or mental disorders. The results are compared to other indigenous diagnostic studies and to the general population. Conclusions—A mental health crisis exists within the indigenous populations that participated in this study. Innovations within current mental health service systems are needed to address the unmet demand of adolescents and families

Disparities in eating disorder risk and diagnosis among sexual minority college students: Findings from the national Healthy Minds Study

ObjectiveTo examine differences in eating disorder (ED) risk and diagnosis by sexual orientation in a national sample of college students.MethodData from 178 U.S. colleges and universities participating in the Healthy Minds Study between 2016 and 2019 were analyzed (36,691 cisgender men, 81,730 cisgender women; 15.7% self‐identifying as sexual minorities). Outcomes were ED risk (≥2 on the SCOFF) and self‐reported lifetime ED diagnosis. Prevalence estimates adjusted for demographics and weight status were computed via logistic regression.ResultsHigher proportions of questioning (29.1%), bisexual (26.3%), and gay men (30.9%) exhibited elevated risk than heterosexual men (14.3%), and a higher proportion of gay men exhibited elevated risk than bisexual men. Higher proportions of questioning (34.5%) and bisexual women (34.6%) exhibited elevated risk than heterosexual women (27.6%); proportions of lesbian (28.1%) and heterosexual women were similar. Among those with elevated risk, higher proportions of bisexual (5.0%) and gay men (7.1%) and of questioning (14.7%), bisexual (18.1%), and lesbian women (19.6%) had been diagnosed relative to heterosexual men (2.0%) and heterosexual women (10.3%), respectively.DiscussionQuestioning and bisexual individuals appear to be particularly vulnerable; they may experience elevated ED risk relative to their heterosexual peers yet underdiagnosis relative to their gay or lesbian peers.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162796/2/eat23304_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162796/1/eat23304.pd

Effects of Exposure to Community Violence and Family Violence on School Functioning Problems among Urban Youth: The Potential Mediating Role of Posttraumatic Stress Symptoms

Adolescents who are exposed to violence during childhood are at an increased risk for developing posttraumatic stress (PTS) symptoms. The literature suggests that violence exposure might also have negative effects on school functioning, and that PTS might serve as a potential mediator in this association. The purpose of the current study was to replicate and extend prior research by examining PTS symptoms as a mediator of the relationship between two types of violence exposure and school functioning problems among ado- lescent youth from an urban setting. Participants included a sample of 121 junior high and high school students (M = 15 years; range = 13–16 years; 60 males, 61 females) within high-crime neighborhoods. Consistent with our hypotheses, community violence and fam- ily violence were associated with PTS symptoms and school functioning problems. Our data suggest that community and family violence were indirectly related to school func- tioning problems through PTS symptoms. Findings from this study demonstrate that PTS symptoms potentially mediate the relationship between violence exposure and school functioning problems across two settings (community and home). Future research should further examine protective factors that can prevent youth violence exposure as well as negative outcomes related to violence

Small-molecule inhibitors of proteins involved in base excision repair potentiate the anti-tumorigenic effect of existing chemotherapeutics and irradiation

There has been a recent upsurge in the development of small-molecule inhibitors specific to DNA repair proteins or proteins peripherally involved in base excision repair and the DNA damage response. These specific, nominally toxic inhibitors are able to potentiate the effect of existing cancer cell treatments in a wide array of cancers. One of the largest obstacles to overcome in the treatment of cancer is incomplete killing with initial cancer treatments, leading to resistant cancer. The progression of our understanding of cancer and normal cell responses to DNA damage has allowed us to develop biomarkers that we can use to help us predict responses of cancers, more specifically target cancer cells and overcome resistance. Initial successes using these small-molecule DNA repair inhibitors in target-validation experiments and in the early stages of clinical trials indicate an important role for these inhibitors, and allow for the possibility of a future in which cancers are potentially treated in a highly specific, individual manner

A study of elective genome sequencing and pharmacogenetic testing in an unselected population

BACKGROUND: Genome sequencing (GS) of individuals without a medical indication, known as elective GS, is now available at a number of centers around the United States. Here we report the results of elective GS and pharmacogenetic panel testing in 52 individuals at a private genomics clinic in Alabama. METHODS: Individuals seeking elective genomic testing and pharmacogenetic testing were recruited through a private genomics clinic in Huntsville, AL. Individuals underwent clinical genome sequencing with a separate pharmacogenetic testing panel. RESULTS: Six participants (11.5%) had pathogenic or likely pathogenic variants that may explain one or more aspects of their medical history. Ten participants (19%) had variants that altered the risk of disease in the future, including two individuals with clonal hematopoiesis of indeterminate potential. Forty-four participants (85%) were carriers of a recessive or X-linked disorder. All individuals with pharmacogenetic testing had variants that affected current and/or future medications. CONCLUSION: Our study highlights the importance of collecting detailed phenotype information to interpret results in elective GS