Disparities in uterine cancer epidemiology, treatment, and survival among African Americans in the United States

OBJECTIVE

The objective of this article is to comprehensively review the scientific literature and summarize the available data regarding the outcome disparities of African American women with uterine cancer.

METHODS

Literature on disparities in uterine cancer was systematically reviewed using the PubMed search engine. Articles from 1992 to 2012 written in English were reviewed. Search terms included endometrial cancer, uterine cancer, racial disparities, and African American.

RESULTS

Twenty-four original research articles with a total of 366,299 cases of endometrial cancer (337,597 Caucasian and 28,702 African American) were included. Compared to Caucasian women, African American women comprise 7% of new endometrial cancer cases, while accounting for approximately 14% of endometrial cancer deaths. They are diagnosed with later stage, higher-grade disease, and poorer prognostic histologic types compared to their Caucasian counterparts. They also suffer worse outcomes at every stage, grade, and for every histologic type. The cause of increased mortality is multifactorial. African American and white women have varying incidence of comorbid conditions, genetic susceptibility to malignancy, access to care and health coverage, and socioeconomic status; however, the most consistent contributors to incidence and mortality disparities are histology and socioeconomics. More robust genetic and molecular profile studies are in development to further explain histologic differences.

CONCLUSIONS

Current studies suggest that histologic and socioeconomic factors explain much of the disparity in endometrial cancer incidence and mortality between white and African American patients. Treatment factors likely contributed historically to differences in mortality; however, studies suggest most women now receive equal care. Molecular differences may be an important factor to explain the racial inequities. Coupled with a sustained commitment to increasing access to appropriate care, on-going research in biologic mechanisms underlying histopathologic differences will help address and reduce the number of African American women who disproportionately suffer and die from endometrial malignancy.

Preclinical evaluation of the WEE1 inhibitor MK-1775 as single-agent anticancer therapy

Inhibition of the DNA damage checkpoint kinase WEE1 potentiates genotoxic chemotherapies by abrogating cell-cycle arrest and proper DNA repair. However, WEE1 is also essential for unperturbed cell division in the absence of extrinsic insult. Here, we investigate the anticancer potential of a WEE1 inhibitor, independent of chemotherapy, and explore a possible cellular context underlying sensitivity to WEE1 inhibition. We show that MK-1775, a potent and selective ATP-competitive inhibitor of WEE1, is cytotoxic across a broad panel of tumor cell lines and induces DNA double-strand breaks. MK-1775-induced DNA damage occurs without added chemotherapy or radiation in S-phase cells and relies on active DNA replication. At tolerated doses, MK-1775 treatment leads to xenograft tumor growth inhibition or regression. To begin addressing potential response markers for MK-1775 monotherapy, we focused on PKMYT1, a kinase functionally related to WEE1. Knockdown of PKMYT1 lowers the EC(50) of MK-1775 by five-fold but has no effect on the cell-based response to other cytotoxic drugs. In addition, knockdown of PKMYT1 increases markers of DNA damage, γH2AX and pCHK1(S345), induced by MK-1775. In a post hoc analysis of 305 cell lines treated with MK-1775, we found that expression of PKMYT1 was below average in 73% of the 33 most sensitive cell lines. Our findings provide rationale for WEE1 inhibition as a potent anticancer therapy independent of a genotoxic partner and suggest that low PKMYT1 expression could serve as an enrichment biomarker for MK-1775 sensitivity.

Discovery of a novel ERK inhibitor with activity in models of acquired resistance to BRAF and MEK inhibitors

The high frequency of activating RAS or BRAF mutations in cancer provides strong rationale for targeting the mitogen-activated protein kinase (MAPK) pathway. Selective BRAF and MAP-ERK kinase (MEK) inhibitors have shown clinical efficacy in patients with melanoma. However, the majority of responses are transient, and resistance is often associated with pathway reactivation of the extracellular signal-regulated kinase (ERK) signaling pathway. Here, we describe the identification and characterization of SCH772984, a novel and selective inhibitor of ERK1/2 that displays behaviors of both type I and type II kinase inhibitors. SCH772984 has nanomolar cellular potency in tumor cells with mutations in BRAF, NRAS, or KRAS and induces tumor regressions in xenograft models at tolerated doses. Importantly, SCH772984 effectively inhibited MAPK signaling and cell proliferation in BRAF or MEK inhibitor-resistant models as well as in tumor cells resistant to concurrent treatment with BRAF and MEK inhibitors. These data support the clinical development of ERK inhibitors for tumors refractory to MAPK inhibitors.

Abstract 699: Optimized dosing strategies resulting in prolonged pathway inhibition enhance dinaciclib anti-tumor activity in preclinical xenograft models

Dinaciclib is a novel CDK1, 2, 5, and 9 inhibitor currently in clinical development for CLL. Preclinical studies indicate that dinaciclib may have activity in a wide variety of indications including hematologic malignancies and solid tumors. Clinically, dinaciclib is administered by 2 hour intravenous (iv) infusion and achieves plasma concentrations above 100nM for ∼6 hours; a concentration and duration of treatment which in vitro provides complete target engagement and induces apoptosis. Pre-clinically, dinaciclib is administered by intraperitoneal (ip) bolus injections and achieves plasma concentrations above 100nM for less than 2 hours. To determine whether prolonged plasma concentrations would enhance dinaciclib activity, we administered dinaciclib to COLO-320DM tumor bearing mice either as a 40 mg/kg single dose, or as two doses of 20 mg/kg separated by 2 hours. This 20-20 split dosing resulted in prolonged target engagement, phospho-RNA-Polymerase-2 reduction, decreased MCL-1, and increased apoptosis relative to the 40mg/kg single dose. Comparing the in vivo anti-tumor activity of dinaciclib dosed at 40 mg/kg ip every 4 days (q4d) vs. 20 mg/kg bid separated by 2 hours q4d demonstrated that the 20-20 split dose increased the anti-tumor activity of dinaciclib (25% Tumor Growth Inhibition (TGI) versus 66% TGI). Dinaciclib single vs. split dosing was further evaluated in 8 lung cancer xenograft models, 5 of which were insensitive to dinaciclib single dose (TGI >50%) and 3 of which were sensitive. 20-20 split dosing resulted in increased anti-tumor activity in all models tested. Split dosing resulted in <50% TGI in 4 of 5 insensitive models. Split dosing also increased anti-tumor activities in all 3 sensitive models tested resulting in stasis in 2 models, and sustained complete regressions in one lung cancer xenograft model. Body weight measurements revealed that split dosing increased body weight loss indicating that prolonged pathway inhibition can affect both anti-tumor activity and tolerability. Taken together, these data suggest that dinaciclib dosing paradigms that prolong pathway inhibition enhanced anti-tumor activity in pre-clinical xenograft models.

Citation Format: Alwin Schuller, Robert Booher, Louise Cadzow, Minilik Angagaw, Lauren Harmonay, Xianlu Qu, Nathan Miselis, Vincenzo Pucci, Mark Ayers, Thorsten Graef, Ellie Im, Rebecca Blanchard, Brian Long, Leigh Zawel, peter strack. Optimized dosing strategies resulting in prolonged pathway inhibition enhance dinaciclib anti-tumor activity in preclinical xenograft models. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 699. doi:10.1158/1538-7445.AM2013-699

Abstract 698: MCL1 dependent cells are sensitive to the CDK inhibitor Dinaciclib

Dinaciclib is a potent inhibitor of cyclin dependent kinases (CDKs) 1, 2, 5, and 9 and is currently in Phase 3 for the treatment of refractory chronic lymphocytic leukemia (CLL). To further understand the mechanism of action, identify predictive biomarkers, and find additional cancer types which may benefit from dinaciclib, we evaluated cell viability following 24 hours treatment across a panel of ∼500 cells lines. Hematopoietic cell lines were on average 3-times more sensitive than solid tumor lines. In agreement with previous findings, mRNA expression of the anti-apoptotic family member BCL-xL or the ratio of MCL1-to-BCL-xL continue to be the best predictor of dinaciclib sensitivity in both hematopoietic and solid tumor cell lines. MCL1 appears to be an important target of dinaciclib particularly in MCL1 amplified cell lines. Dependence on MCL1 was established in a panel of 19 breast, NSCLC and SCLC cell lines by depletion of the protein by either dinaciclib treatment or MCL1 RNAi. The NSCLC line H23 was highly dependent on MCL1, as RNAi knockdown decreased viability to <20% and could be rescued by introduction of a non-targeted MCL1 expression construct. In the H23 xenograft, dinaciclib diminished MCL1 levels and induced tumor apoptosis resulting in >80% tumor regression. Cell lines which lacked pro-apoptotic proteins BAX / BAK or harbored a BAX mutation were insensitive to the inhibitor. Using apoptosis defective lines we demonstrate that 24 hours of dinaciclib treatment still impacted cell count by blocking cell cycle progression as measured by FACS. These data demonstrate that both cell cycle block and induction of apoptosis contribute to dinaciclib's mechanism of action. However, the observation that MCL1 and BCL-xL were top genes associated with sensitivity suggests that induction of apoptosis is the predominant mechanism of dinaciclib's anti-tumor effect and warrants further investigation of MCL1 amplification as a predictive biomarker in future clinical studies.

Citation Format: Harold Hatch, Robert Booher, Samanthi Perera, Thi Nguyen, Brian Dolinski, Samer Al-Assaad, Lauren Harmonay, Alwin Schuller, Minilik Angagaw, Brian Long, Xianlu Qu, Nathan Miselis, Mark Ayers, Michael Nebozhyn, Heather Hirsch, Danielle Greenawalt, Andrey Loboda, Thorseten Graef, Ellie Im, Rebecca Blanchard, Leigh Zawel, Peter Strack. MCL1 dependent cells are sensitive to the CDK inhibitor Dinaciclib. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 698. doi:10.1158/1538-7445.AM2013-698

LOX-1 abrogation reduces cardiac hypertrophy and collagen accumulation following chronic ischemia in the mouse

We hypothesized that lectin-like oxidized LDL receptor-1 (LOX-1) deletion may inhibit oxidative stress signals, reduce collagen accumulation and attenuate cardiac remodeling after chronic ischemia. Activation of LOX-1 plays a significant role in the development of inflammation, apoptosis and collagen signals during acute ischemia. Wild-type and LOX-1 knockout (KO) mice were subjected to occlusion of left coronary artery for 3 weeks. Markers of cardiac hypertrophy, fibrosis-related signals (collagen IV, collagen-1 and fibronectin) and oxidant load (nicotinamide adenine dinucleotide phosphate oxidase expression, activity of mitogen-activated protein kinases and left ventricular (LV) tissue thiobarbituric acid reactive substances) were analyzed. In in vitro experiments, HL-1 cardiomyocytes were transfected with angiotensin II (Ang II) type 1 receptor (AT1R) or type 2 receptor (AT2R) genes to determine their role in the cardiomyocyte hypertrophy. LOX-1 KO mice had 25% improvement in survival over the 3-week period of chronic ischemia. LOX-1 deletion reduced collagen deposition and cardiomyocyte hypertrophy (∼75%) in association with a decrease in oxidant load and AT1R upregulation (all P<0.05). The LOX-1 KO mice hearts exhibited a disintegrin and metalloproteinase 10 (ADAM10) and a disintegrin and metalloproteinase 17 (ADAM17) expression and matrix metalloproteinase 2 activity, and increased AT2R expression (P<0.05). Attenuation of cardiac remodeling was associated with improved cardiac hemodynamics (LV ±dp/dt and cardiac ejection fraction). In vitro studies showed that it is AT1R, and not AT2R overexpression that induces cardiomyocyte hypertrophy. We demonstrate for the first time that LOX-1 deletion reduces oxidative stress and related intracellular signaling, which leads to attenuation of the positive feedback loop involving AT1R and LOX-1. This results in reduced chronic cardiac remodeling.

Correlation between promoter methylation of glutathione-S-tranferase P1 and oxidative stress in acute-on-chronic hepatitis B liver failure

Promoter methylation of glutathione-S-transferase P1 (GSTP1) may be involved in liver damage caused by oxidative stress in acute-on-chronic hepatitis B-induced liver failure (ACHBLF). This study aimed to explore GSTP1 promoter methylation status and oxidative stress in such patients. DNA was extracted from peripheral blood mononuclear cells (PBMCs) of patients with acute-on-chronic liver hepatitis B-induced liver failure, chronic hepatitis B (CHB) and normal controls, followed by sodium-bisulfite treatment and methylation-specific PCR (MSP) analysis. Plasma malondialdehyde (MDA) adducts levels were detected by enzyme-linked immunosorbent assay as oxidative stress marker. Model for end-stage liver disease (MELD) score was employed to estimate the severity of the liver failure. Eleven of 35 patients with acute-on-chronic liver failure and 3 of 35 patients with stab le hepatitis B displayed GSTP1 promoter methylation, and the difference was significant (χ2)  = 5.71, P = 0.02). No differences in standard liver function tests were found in patients with acute-on-chronic liver failure with and without GSTP1 promoter methylation although the levels of total bilirubin were greater in those with methylation. The levels of MDA adducts were significantly higher in patients with liver failure when compared to those with CHB (12.44 ± 5.38 pmol/mg vs 8.42 ± 5.49 pmol/mg, P < 0.01), and in the patients with liver failure who had promoter methylation the levels were higher than in those who did not (15.2 ± 4.68 pmol/mg vs 11.17 ± 5.29 pmol/mg, P < 0.01). The MELD score was not significantly different between methylated and unmethylated patients with liver failure (P > 0.05), although MDA adducts were correlated with MELD scores in patients with acute-on-chronic liver failure (r = 0.579, P < 0.01). GSTP1 promoter methylation may facilitate oxidative stress-associated liver damage in ACHBLF, and oxidative stress is correlated with ACHBLF severity.

Executive function following child stroke: the impact of lesion location

Child stroke is a major cause of death in children, although limited information exists on neurobehavioral functioning of stroke survivors. Executive function (important for goal-directed behavior) is thought to be vulnerable to early insults such as stroke because of its widespread representation in the immature brain. This study investigated the impact of lesion location on executive skills. Twenty-eight children diagnosed with stroke at least 18 months before assessment were recruited. Lesion characteristics were coded from magnetic resonance imaging (MRI) scans. Neurobehavioral assessment focused on cognitive and everyday executive skills. Deficits were found in the context of overall normal intellectual functioning (M = 91.60; SD = 19.40). Generally, insults involving frontal and extra-frontal regions impacted equally on cognitive performance. Everyday deficits were marginally more prominent following frontal insult. Subcortical frontal lesions were associated with impairments in everyday executive skills. Results provide further support for the diffuse representation of executive function in the immature brain.

Design of reversible cross-linkers for step and flash imprint lithography imprint resists

Progress in the semiconductor manufacturing industry depends upon continuous improvements in the resolution of lithographic patterning through innovative materials development and frequent retooling with expensive optics and radiation sources. Step and Flash Imprint Lithography is a low-cost, nanoimprint lithography process that generates nanopatterned polymeric films via the photopolymerization of low-viscosity solutions containing cross-linking monomers in a transparent template (mold). The highly cross-linked imprint materials are completely insoluble in all inert solvents, which poses a problem for reworking wafers with faulty imprints and cleaning templates contaminated with cured imprint resist. Degradable cross-linkers provide a means of stripping cross-linked polymer networks. The controlled degradation of polymers containing acetal- and tertiary ester-based cross-linkers is demonstrated herein. The viscosity and dose to cure are presented for several prepolymer formulations, along with imprint resolution and tensile modulus results for the cured polymers. Optimum conditions for de-cross-linking and stripping of the cross-linked polymers are presented, including demonstrations of their utility.

Alphaviral vector-transduced dendritic cells are successful therapeutic vaccines against neu-overexpressing tumors in wild-type mice

While dendritic cell (DC) vaccines can protect hosts from tumor challenge, their ability to effectively inhibit the growth of established tumors remains indeterminate. Previously, we have shown that human DCs transduced with Venezuelan equine encephalitis virus replicon particles (VRPs) were potent stimulators of antigen-specific T cells in vitro. Therefore, we investigated the ability of VRP-transduced DCs (VRP-DCs) to induce therapeutic immunity in vivo against tumors overexpressing the neu oncoprotein. Transduction of murine DCs with VRPs resulted in high-level transgene expression, DC maturation and secretion of proinflammatory cytokines. Vaccination with VRP-DCs expressing a truncated neu oncoprotein induced robust neu-specific CD8(+) T cell and anti-neu IgG responses. Furthermore, a single vaccination with VRP-DCs induced the regression of large established tumors in wild-type mice. Interestingly, depletion of CD4(+), but not CD8(+), T cells completely abrogated inhibition of tumor growth following vaccination. Taken together, our results demonstrate that VRP-DC vaccines induce potent immunity against established tumors, and emphasize the importance of the generation of both CD4(+) T cell and B cell responses for efficient tumor inhibition. These findings provide the rationale for future evaluation of VRP-DC vaccines in the clinical setting.

Seasonal Variability in Otariid Energetics: Implications for the Effects of Predators on Localized Prey Resources

Otariids, like other wild mammals, contend with a wide variety of energetic demands across seasons. However, due to the cryptic behaviors of this marine group, few studies have been able to examine longitudinal energetic costs or the potential impact of these costs on seasonal or annual prey requirements. Here we evaluated the changes in energy demand and intake of female California sea lions (Zalophus californianus) during reproductive (n=2 sea lions) and nonreproductive (n=3) periods. Monthly measurements included resting metabolic rate, blood hormone levels, body condition (blubber thickness and body mass), and caloric intake for adult sea lions throughout molting, late pregnancy, lactation, and postweaning. We found that maintenance energy demands decreased from 32.0 to 23.1 MJ d(-1) before pupping, remaining stable at 19.4+/-0.6 MJ d(-1) during lactation and postweaning. Energy intake rates to meet these demands showed marked changes with activity level and the reproductive cycle, reaching a peak intake of 3.6 times baseline levels during lactation. Translating this into prey demands, we find that 20,000 reproductively active females on San Nicolas Island rookeries would maximally require 4,950 metric tons of Pacific whiting during a month of the breeding season. This localized impact is reduced significantly with postbreeding dispersal and demonstrates the importance of considering spatial and temporal factors driving the energetic requirements of predators when designing marine protected areas.

Identical beta cell-specific CD8(+) T cell clonotypes typically reside in both peripheral blood lymphocyte and pancreatic islets

A major issue regarding T cell responses in autoimmunity is how the repertoire compares between the periphery and target organ. In type 1 diabetes, the status of at-risk or diabetic individuals can be monitored by measuring beta cell-specific T cells isolated from PBL, but whether these T cells accurately reflect the repertoire residing in the pancreatic islets is unclear. The TCR repertoire of disease-relevant, tetramer-sorted CD8(+) T cells was examined at the single-cell level in PBL, pancreatic lymph nodes (PLN), and the islets of individual NOD mice. CDR3alpha and CDR3beta sequences demonstrated that the same repertoire of T cells in PBL was detected in the islets and PLN, although the frequency of specific clonotypes varied. Albeit infrequent, clonotypes that were prevalent in the islets but not found in PBL were also detected. beta cell Ag immunization expanded immunodominant PBL clonotypes present in the islets and PLN. These results show that insight into repertoire profiles of islet-infiltrating T cells can be obtained from PBL.

Elastic path controller for assistive devices

Robotic assistive devices that constrain motion along pre-defined paths are useful in reducing maneuvering efforts by human. This paper introduces an Elastic Path Controller (EPC) that adds "elasticity" to the path following and enables dynamic modification of the paths. This permits the users to compensate for changes in the environment such as introduction of new obstacles or for errors in position sensing. The experiments performed on a Scooter cobot show that users can learn to use this novel tool to modify and design guiding paths in a relatively simple way. The operators use the EPC by pushing/pulling against the guided paths to produce the desired deformations. Then, by just dropping the forces and trusting the path controller, they will be brought back to the guided paths.