Abstract The IKZF1 gene encodes IKAROS – a DNA binding protein that acts as a tumor suppressor in T-cell acute lymphoblastic leukemia (T-ALL). IKAROS can act as a transcriptional repressor via recruitment of histone deacetylase 1 (HDAC1) and chromatin remodeling, however the mechanisms through which Ikaros exerts its tumor suppressor function via heterochromatin in T-ALL are largely unknown. We studied human and mouse T-ALL using a loss-of-function and IKZF 1 re-expression approach, along with primary human T-ALL, and normal human and mouse thymocytes to establish the role of Ikaros and HDAC1 in global regulation of facultative heterochromatin and transcriptional repression in T-ALL. Results identified novel Ikaros and HDAC1 functions in T-ALL: Both Ikaros and HDAC1 are essential for EZH2 histone methyltransferase activity and formation of facultative heterochromatin; recruitment of HDAC1 by Ikaros is critical for establishment of H3K27me3 histone modification and repression of active enhancers; and Ikaros-HDAC1 complexes promote formation and expansion of H3K27me3 Large Organized Chromatin lysine (K) domains (LOCKs) and Broad Genic Repression Domains (BGRDs) in T-ALL. Our results establish the central role of Ikaros and HDAC1 in activation of EZH2, global regulation of the facultative heterochromatin landscape, and silencing of active enhancers that regulate oncogene expression.
○ This issue of the ARCHIVES includes previously unpublished protocols for the examination of specimens removed from patients with cancer of diverse sites. We provide a historical context for the development of these protocols and describe the process of development and approval. General information about the structure and content of the protocols is also provided. Cancer protocol development is an important step in the process of standardized cancer reporting. The value of such standardized reporting is discussed.
Time and frequency of signal-averaged electrocardiograms from 51 patients and 19 normal subjects were studied. A new filter device was designed to facilitate the analysis of the complete QRS complex, particularly the high-frequency components. All patients underwent electrical programmed stimulation (EPS) with up to three extra stimuli. In 29 patients, sustained ventricular tachycardia (VT) was inducible (group A), whereas in 22, sustained VT could not be elicited (group B). Between A and B, we compared several variables from the signal-averaged ECG as well as clinical data. The variables that differed between the two groups (P<0·01 were entered into a logistic regression model to determine which ones could most reliably predict the outcome of EPS. A combination of three variables (number of minima and maxima in the terminal QRS; third of four areas of equal length, divided by the total area below the QRS; maximum of the frequency spectre in the terminal QRS) could predict the inducibility of sustained VT with 82·8% sensitivity and 86·4% specifity.
Aims: Evidence from post mortem and MRI studies suggests that a dysfunction of glia cells might represent a pathogenic factor for schizophrenia. The astrocytic protein S100B regulates the balance between proliferation and differentiation in neurons and glia cells by modulating protective and apoptotic mechanisms. It therefore represents a marker for glial cell dysfunction, and has been shown to be increased in schizophrenia. However, until now only serum concentrations of S100B have been reported on in schizophrenic patients. This study represents the first attempt to study CSF and serum S100B concentrations in schizophrenia simultaneously.
Abstract Background: Pre-B cell Acute lymphoblastic leukemia (B ALL) high risk (HR) subgroups continue to result in significant mortality and morbidity of pediatric oncology patients. T cell ALL is higher risk and therapy has made less improvement than B ALL with a higher rate of significant poor outcomes. Novel treatment strategies are required to overcome chemotherapy resistance and improve mortality/morbidity for HR B ALL. Leonurine is a bioactive alkaloid that is naturally occurring only in Herbra Leonuri which has been used in traditional herbal medicine. Traditionally, it has been used for menstrual disorders. Research has further described its ability to scavenge oxygen free radicals, anticoagulation properties, and other anti-inflammatory properties[1]. There are investigations in its role for myocardial infarction, stroke, chronic kidney disease, and other inflammatory disorders[2]. Our research data that suggests that leonurine and its derivatives have antileukemic effects.Methods/Results: We analyzed multiple derivatives of leonurine and selected a potent candidate based on cell viability assays use for further testing designated as investigational leonurine derivative (ILD). WST1 proliferation studies comparing ILD to vehicle were performed in cell lines Nalm6, 697, Molt4, CEM, and JM1 at multiple time points. The half maximal inhibitory concentration (IC50) values was variable depending on the treatment time and cell line although all values were consistently between 1.2-4.4 uM. Apoptosis activity was determined by flow cytometry Anexin/7AAD assays showed increased apoptosis in cell lines treated with ILD for Nalm6, Molt4, and 697 cell lines. Caspase 3/7 activity was increased in cells treated with ILD when compared to vehicle treatment. DNA damage assays were performed which revealed only an increased frequency in single strand breaks and not double strand breaks. Western blot was performed to determine levels of PI3K, p-AKT, BCL2/BCL-XL and caspases. The blots suggest that apoptosis may be a result of increased activation of PI3K/AKT signaling. We performed RNAseq on cells treated with ILD at the 24-hour time point and present gene ontology data for this analysis. Nalm6, 697, and Molt4 cell lines expressing GFP and Luciferase were injected into NRG mice as means for in vivo pharmacologic testing. NRG mice injected with these cell lines were treated with ILD five days a week for a total of 3 weeks. Nalm 6 leukemia cells showed minimal differences between treatment and control groups.Conclusion: In summary, leonurine derivatives have a promising impact on apoptosis and cell survival. Further investigation into mechanisms and pharmacokinetics/dynamics will be more revealing. Study of leonurine derivatives will result in further translational and therapeutic applications. Citation Format: Joseph W. Schramm, Melanie Ehudin, Bing He, Chingakham Singh, Daniel Bogush, Jeremy Hengst, Diwakar Bastihalli Tukaramrao, Arati Sharma, Dhimant Desai, Sinisa Dovat. Leonurine derivatives as a potential novel therapeutic approach to acute lymphoblastic leukemias (ALL). [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3833.
Neuroblastoma is a common childhood malignancy, and high-risk presentations, including an MYCN amplified status, continue to result in poor survival. Difluoromethylornithine (DFMO) is a new and well-tolerated treatment for high-risk neuroblastoma. This review article discusses preclinical and clinical data that resulted in the establishment of DFMO as a treatment for neuroblastoma. The review of preclinical data includes a summary of the contribution of polyamine synthetic pathways to high-risk neuroblastoma, the effect that MYCN has on polyamine synthetic pathways, and the proposed mechanism by which DFMO inhibits tumorigenesis. This understanding has led to the discussion of various preclinical combination therapies that may result in a synergistic therapeutic response for high-risk neuroblastoma. We review the clinical trials that show the successful treatment of high-risk neuroblastoma with DFMO, including comparative analysis and traditional neuroblastoma trials using propensity score matching. We review the regulatory path by which DFMO gained approval from the Federal Drug Administration for use as a maintenance therapy following the traditional high-risk neuroblastoma therapy. Finally, we discuss the role of DFMO in future clinical research for neuroblastoma and additional pediatric cancers.
Abstract B-Cell Acute Lymphoblastic Leukemia (B-ALL) is the most common childhood malignancy. Hispanic/Latino (H/L) children have a 40% higher death rate than non-Hispanic white (NHW) children after correcting for socioeconomic factors. Recently, we identified a 3.5-fold increased incidence of deletion of one IKZF1 allele (IKZF1-del) and over 15-fold increased incidence of deletion of one IKZF1 allele concomitant with IGH-CRLF2 translocation (IKZF1-del/IGH-CRLF2) in B-ALL of H/L children. This provided a biological rationale for the worse prognosis of B-ALL in H/L children. The very high incidence (29% in all H/L children and 60% in ≥10yr old H/L children) makes IKZF1-del the most frequent genetic alteration that confers adverse prognosis in B-ALL in H/L children. The IKZF1 gene encodes a DNA-binding protein, IKAROS, which regulates transcription of its target genes via chromatin remodeling. The purpose of the study is to analyze the global epigenomic regulation of gene expression in H/L and NHW children with B-ALL and identify biological determinants of altered gene expression that result in worse prognosis for H/L children with B-ALL. /. B-ALL primary cells from 60 H/L and NHW children were analyzed with whole genome sequencing and gene expression profiling using RNA-seq. A subset of B-ALL from each group was analyzed for epigenomic changes by Reduced Representation Bisulfite Sequencing (RRBS), ChIP-seq, CUT&RUN, and CUT&Tag. Results showed that gene expression pattern in B-ALL of H/L children is quite different from B-ALL of NHW children. GSEA and Ingenuity pathway analysis identified oncogenic drivers of B-ALL in H/L children. B-ALL of H/L children have elevated expression of genes that promotestemness, inflammation, and with antiapoptotic activity. RBBS analysis showed a distinct DNA methylation pattern in B-ALL in H/L vs NHW children at promoters of a large set of genes that are involved in cellular signaling, RNA processing, and cellular proliferation. Presence of IKZF1-del results in the alteration of global epigenomic regulation of gene expression with altered enhancer and super-enhancer landscape. Epigenomic alterations due to IKZF1-del resulted in profound redistribution of enhancers and super-enhancers in B-ALL of both H/L vs. NHW children. This was associated with a distinct alteration in gene expression and uncovered that IKAROS regulates different sets of genes in B-ALL in H/L vs. NHW children. These data identified a unique oncogenic signaling that are responsible for aggressive course of B-ALL in H/L children. In conclusion, the multiomics analysis of primary B-ALL cells revealed a distinct global epigenomic regulation of gene expression between B-ALL from H/L and NHW children. This was demonstrated by alterations in DNA methylation and enhancer landscape. Presence of IKZF1-del has a different effect on gene expression in B-ALL of H//L vs NHW children. Results of the study provide a biological rationale for the worse prognosis of B-ALL in H/L children and identified novel therapeutic targets for this disease. Citation Format: Laura Budurlean, Bing He, Yali Ding, Diwakar Bastihalli Tukaramrao, Chingakham Singh, Joseph Schramm, Daniel Bogush, James Broach, Sinisa Dovat. Distinct epigenomic regulation of gene expression in Hispanic/Latino children with high-risk B-cell acute lymphoblastic leukemia [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr C055.
