Biallelic TET2 mutations confer sensitivity to 5'-azacitidine in acute myeloid leukemia

Precision medicine can significantly improve outcomes for patients with cancer, but implementation requires comprehensive characterization of tumor cells to identify therapeutically exploitable vulnerabilities. Here, we describe somatic biallelic TET2 mutations in an elderly patient with acute myeloid leukemia (AML) that was chemoresistant to anthracycline and cytarabine but acutely sensitive to 5'-azacitidine (5'-Aza) hypomethylating monotherapy, resulting in long-term morphological remission. Given the role of TET2 as a regulator of genomic methylation, we hypothesized that mutant TET2 allele dosage affects response to 5'-Aza. Using an isogenic cell model system and an orthotopic mouse xenograft, we demonstrate that biallelic TET2 mutations confer sensitivity to 5'-Aza compared with cells with monoallelic mutations. Our data argue in favor of using hypomethylating agents for chemoresistant disease or as first-line therapy in patients with biallelic TET2-mutated AML and demonstrate the importance of considering mutant allele dosage in the implementation of precision medicine for patients with cancer.

Multidrug-related protein 1 (MRP1) polymorphisms rs129081, rs212090, and rs212091 predict survival in normal karyotype acute myeloid leukemia

Resistant disease is still a main obstacle in acute myeloid leukemia (AML) treatment. Therefore, individual genetic variations affecting therapy response are gaining increasing importance. Both SNPs and ABC transporter genes could already be associated with drug resistance. Here, we report allelic variants of MRP1 (ABCC1) SNPs rs129081, rs212090, and rs212091 with significant influences on survival in AML patients. DNA was extracted from bone marrow samples (n = 160) at diagnosis. Genotyping 48 SNPs within seven different ABC transporter genes using real-time PCR revealed rs129081 GG variant with a significant higher OS (p = 0.035) and DFS (p = 0.01). Comparing TT and AA rs212090 variants showed significant influences on DFS (p = 0.021). SNP rs212091 GG expression was associated with worse OS (p = 0.006) and a significant difference in DFS between alleles GG and AA (p = 0.018). The multivariable models confirmed a significant influence on OS for rs212091 (AA HR = 0.296, 95% CI 0.113–0.774, p = 0.013 and GG p = 0.044). Rs129081 variant CG, TT of rs212090, AA, and AG of rs212091 demonstrated significant impact on DFS (p = 0.024, p = 0.029, p = 0.017, and p = 0.042, respectively). This analysis demonstrates a significant influence of MRP1 SNPs on survival in AML. As they were not associated to prognostic characteristics, we suggest these SNPs to be independent prognostic markers for AML.

Lysyl oxidase expression is associated with inferior outcome and Extramedullary disease of acute myeloid leukemia

BACKGROUND

Lysyl oxidase (LOX) has been described as necessary for premetastatic niche formation in epithelium-derived malignancies and its expression level therefore correlates with risk of metastatic disease and overall survival. However, its role in acute myeloid leukemia (AML) has not been sufficiently analyzed.

METHODS

We investigated LOX plasma expression in 683 AML patients (age 17-60 years) treated within the prospective AML2003 trial (NCT00180102). The optimal cut-off LOX value was determined using a minimal-p-value method dichotomizing patients into a LOX-high group (> 109 ng/mL, n = 272, 40%) and a LOX-low group (≤ 109 ng/mL, n = 411, 60%).

RESULTS

Higher LOX expression was associated with lower peripheral white blood cells, lower serum LDH, and a lower frequency of FLT3-ITD and NPM1 mutations at diagnosis. Higher LOX expression was found significantly more frequently in patients with secondary AML and therapy-related AML, in patients with French-American-British M5 subtypes, and in patients with adverse-risk cytogenetics. Comparing patients in the LOX-high group and the LOX-low group revealed a 3-year overall survival (OS) of 47 and 53% (p = 0.022) and 3-year event-free survival (EFS) of 27 and 35% (p = 0.005), respectively. In the LOX-high group significantly more patients had extramedullary AML compared to the LOX-low group (p = 0.037). Combining extramedullary AML and LOX as interacting factors in a multivariate analysis resulted in an independent impact on survival for the LOX-high-extramedullary interaction for OS (HR = 2.25, p = 0.025) and EFS (HR = 2.48, p = 0.008). Furthermore, in patients with extramedullary disease (n = 59) the LOX level predicted survival. Patients within the LOX-low group had an OS of 43% and EFS of 36% as compared to the LOX-high group with an OS of 13% and EFS of 6% (p = 0.002 and p = 0.008, respectively).

CONCLUSION

We hypothesize LOX expression to be a new potential biomarker to predict outcome in AML, specifically in AML subgroups such as the prognostic heterogeneous group of AML patients with extramedullary disease.

TRIAL REGISTRATION

This retrospective study was performed with patient samples registered within the prospective AML2003 trial (NCT00180102). Patients were enrolled between December 2003 and November 2009.

Allocating effort and anticipating pleasure in schizophrenia: Relationship with real world functioning

BACKGROUND

Poor motivation to engage in goal-oriented behavior has been recognized as a hallmark feature of schizophrenia spectrum disorders (SZ). Low drive in SZ may be related to anticipating rewards as well as to poor working memory. However, few studies to date have examined beliefs about self-efficacy and satisfaction for future rewards (anticipatory pleasure). Additionally, few studies to date have examined how these deficits may impact SZ patients' real world functioning.

METHOD

The present study examined SZ patients' (n=57) anticipatory pleasure, working memory, self-efficacy and real world functioning in relation to their negative symptom severity.

RESULTS

Results revealed that SZ patients' negative symptom severity was related to decisions in effort allocation and reward probability, working memory deficits, self-efficacy and anticipatory pleasure for future reward. Effort allocation deficits also predicted patients' daily functioning skills.

CONCLUSIONS

SZ patients with high levels of negative symptoms are not merely effort averse, but have more difficulty effectively allocating effort and anticipating pleasure engaging in effortful activities. It may be the case that continuously failing to achieve reinforcement from engagement and participation may lead SZ patients to form certain negative beliefs about their abilities which contributes to amotivation and cognitive deficits. Lastly, our findings provide further support for a link between SZ patients functional daily living skills their effort allocation.

Regulation of oxidative stress by Nrf2 in the pathophysiology of infectious diseases

The innate immune system, including phagocytic cells, is the first line of defense against pathogens. During infection by microorganisms such as viruses, bacteria, or parasites, phagocytic cells produce an excess of oxidants, a crucial process for the clearance of pathogens. This increase in oxidants creates an imbalance between oxidants and endogenous antioxidants. Left unchecked, this acute or chronic oxidative stress can lead to apoptotic cell-death and oxidative stress-induced diseases including neurodegenerative and cardiovascular disorders, premature aging, secondary infections, and cancer. The activation of nuclear factor E2-related factor 2 (Nrf2) is an efficient antioxidant defensive mechanism used by host cells to counteract oxidative stress. The transcription factor Nrf2 has been identified as the master regulator of several hundred of genes involved in the antioxidant defense response. The review objectives were to collect recent findings on the contribution of oxidative stress to complications of infection, and to highlight the beneficial impact of antioxidants in reducing inflammation and oxidant-related tissue damage. Furthermore, a direct relationship between infection and decline in Nrf2 activity has been demonstrated. Thus, an interesting therapeutic approach in disease prevention and treatment of stress-related diseases may consist in optimizing antibiotic or antiviral therapy with a combination of Nrf2 inducer treatment.

Immunohistochemical study of HLA-G expression in lung transplant recipients

Human leukocyte antigen-G (HLA-G), a nonclassical HLA class I protein, promotes immune tolerance of solid-organ allografts, yet its role in lung transplantation (LTx) is unknown. We examined the expression of HLA-G in lung allografts through immunohistochemistry by a cross-sectional study of 64 LTx recipients, classified into four groups (stable patients, acute rejection [AR], bronchiolitis obliterans syndrome [BOS] and symptomatic viral shedders). A marked expression of HLA-G in bronchial epithelial cells (BEC) was frequently observed in stable recipients (n = 18/35 [51%]), but not in patients with AR (n = 14) or with BOS (n = 8). HLA-G was also expressed by 4 of 7 symptomatic viral shedders. In addition, HLA-G-positive patients from the stable group (n = 35) experienced lower incidence of resistant AR and/or BOS during long-term follow-up, as compared with their HLA-G-negative counterparts. Finally, in vitro data showed that interferon-gamma, a cytokine present in lung allograft microenvironment, upregulated HLA-G mRNA and protein expression in primary cultured human BEC. We conclude that HLA-G expression in the bronchial epithelium of lung allograft is elevated in some LTx recipients in association with their functional stability, suggesting a potential role of HLA-G as a tolerance marker.

A MDR1 (ABCB1) gene single nucleotide polymorphism predicts outcome of temozolomide treatment in glioblastoma patients

BACKGROUND

Some patients with glioblastoma multiform do not respond to temozolomide even though they have aberrant promoter methylation of the DNA repair enzyme O(6)-methylguanine methyltransferase (MGMT). This suggests that additional factors hamper temozolomide cytotoxicity. We aimed to confirm first that temozolomide is a target for the multidrug resistance transporter MDR1/ABCB1 and second to investigate whether genetic variants of the MDR1 gene are associated with the survival of glioblastoma patients treated with temozolomide.

MATERIALS AND METHODS

Temozolomide-mediated cytotoxicity was determined by the colorimetric methyl-thiazol-tetrazolium assay in MDR-expressing and MDR-nonexpressing cell lines. Genotypes of three single nucleotide polymorphisms (SNPs) of the MDR1 gene (C1236T, G2677T, and C3435T), MDR1 mRNA expression levels, and the MGMT promoter methylation status were analyzed in 112 glioblastoma patients who had been treated either by surgery plus radiotherapy alone or by additional temozolomide chemotherapy.

RESULTS

In vitro analysis revealed that temozolomide-mediated cytotoxicity is dependent on MDR1 expression. Multivariate analysis of MDR1 genotypes showed that the C/C variant of the exon12 C1236T SNP is predictive for survival of patients treated with temozolomide. This effect was independent of the MGMT methylation status. Patients with the C/C genotype had a 2-year overall survival of 37% compared with 8% and 10% for patients with C/T and T/T genotypes, respectively (P=0.02). No influence was seen in the group of patients with radiotherapy only.

CONCLUSION

The genotype of the MDR1 exon12 C1236T SNP is a novel independent predictive factor for outcome of temozolomide treatment in glioblastoma patients.

Reversible neuropsychological deficits after mild traumatic brain injury

OBJECTIVES

To determine the influence of motivation on performance in a divided attention test of patients after mild traumatic brain injury (MBI).

METHODS

Comparison of the performance of 12 patients with MBI with 10 patients with severe brain injury (SBI) and 11 healthy controls in a computer supported divided attention task before (T1) and after (T2) verbal motivation.

RESULTS

At T1, the MBI group performed the same as the SBI group but significantly worse than the controls in all variables. At T2, the MBI group performed worse than the controls at T2 but the results were equal to the results of the controls at T1 and significantly better than the SBI group at T1 or T2. At T2 the MBI group performed at the level of published norms for the rest.

CONCLUSION

Before verbal motivation the MBI group's results in the divided attention task were comparable with those from patients with severe brain injury. They failed to exploit their performance potential when it depended on self motivation but were able to perform at the level of the control group when external motivation was applied.

Glaucoma: what the ophthalmic nurse should know

Glaucoma is both an international and a national public health issue. Worldwide, glaucoma is one of the leading causes of blindness. More than 2 million persons in the United States have glaucoma, yet only half of them are aware that they have the disease. The diagnosis of glaucoma requires an extensive ocular examination. Glaucoma consists of a group of ocular diseases that result in optic disk cupping and visual field loss. Although glaucoma is a blinding disease, in most cases, blindness may be prevented through early detection and treatment. Glaucoma management is determined by the type of glaucoma a person has.

Glaucoma: what the nurse practitioner should know

Glaucoma is both an international and a national public-health issue. Worldwide, glaucoma is one of the leading causes of blindness. Although more than two million people in the United States have glaucoma, yet only half of them are aware that they have the disease. The diagnosis of glaucoma requires an extensive ocular examination. Glaucoma consists of a group of ocular diseases that result in optic disk cupping and visual field loss. Although glaucoma is a blinding disease, in most cases, blindness may be prevented through early detection and treatment. Glaucoma management is determined by the type of glaucoma one has.

The research report: analysis of the findings, Part 1

The purpose of the results section of the research report is to answer the research questions (the hypotheses) in the order they were asked (Thomas, 1990), to justify the use of the analytic technique used to answer the questions, to use tables and figures (where appropriate) to clarify and highlight relevant findings with an accompanying narrative, and to identify limitations.