The Dawn of Allosteric BCR-ABL1 Drugs: From a Phenotypic Screening Hit to an Approved Drug.

Chronic myeloid leukemia (CML) is driven by the constitutive activity of the BCR-ABL1 fusion oncoprotein. Despite the great success of drugs that target the BCR-ABL1 ATP-binding site in transforming CML into a manageable disease, emerging resistance point mutations impair inhibitor binding, thereby limiting the effectiveness of these drugs. Recently, allosteric inhibitors that interact with the ABL1 myristate-binding site have been shown to awaken an endogenous regulatory mechanism and reset full-length BCR-ABL1 into an inactive assembled state. The discovery and development of these allosteric inhibitors demonstrates an in-depth understanding of the fundamental regulatory mechanisms of kinases. In this review, we illustrate the structural basis of c-ABL1's dynamic regulation of autoinhibition and activation, discuss the discovery of allosteric inhibitors and the characterization of their mechanism of action, present the therapeutic potential of dual binding to delay the development of mutation-driven acquired resistance, and suggest key lessons learned from this program

Validation of DNA methylation to predict outcome in acute myeloid leukemia by use of xMELP

Epigenetic dysregulation involving alterations in DNA methylation is a hallmark of various types of cancer, including acute myeloid leukemia (AML). Although specific cancer types and clinical aggressiveness of tumors can be determined by DNA methylation status, the assessment of DNA methylation at multiple loci is not routinely performed in the clinical laboratory. We recently described a novel microsphere-based assay for multiplex evaluation of DNA methylation. In the current study, we validated and used an improved assay [termed expedited microsphere HpaII small fragment Enrichment by Ligation-mediated PCR (xMELP)] that can be performed with appropriate clinical turnaround time. Using the xMELP assay in conjunction with a new 17-locus random forest classifier that has been trained using 344 AML samples, we were able to segregate an independent cohort of 70 primary AML patients into methylation-determined subgroups with significantly distinct mortality risk (P = 0.009). We also evaluated precision, QC parameters, and preanalytic variables of the xMELP assay and determined the sensitivity of the random forest classifier score to failure at 1 or more loci. Our results demonstrate that xMELP performance is suitable for implementation in the clinical laboratory and predicts AML outcome in an independent patient cohort

Changes in Paracrine Interleukin-2 Requirement, CCR7 Expression, Frequency, and Cytokine Secretion of Human Immunodeficiency Virus-Specific CD4(+) T Cells Are a Consequence of Antigen Load

Virus-specific CD4(+) T-cell responses are thought to be required for the induction and maintenance of many effective CD8(+) T-cell and B-cell immune responses in experimental animals and humans. Although the presence of human immunodeficiency virus (HIV)-specific CD4(+) T cells has been documented in patients at all stages of HIV infection, many fundamental questions regarding their frequency and function remain. A 10-color, 12-parameter flow cytometric panel was utilized to examine the frequency, memory phenotype (CD27, CCR7, and CD45RA), and cytokine production (interleukin-2 [IL-2], gamma interferon, and tumor necrosis factor alpha) of CD4(+) T cells specific for HIV antigens as well as for adenovirus, Epstein-Barr virus (EBV), influenza H1N1 virus, influenza H3N2 virus, cytomegalovirus, varicella-zoster virus (VZV), and tetanus toxoid in normal controls, long-term nonprogressors (LTNP), and HIV-infected patients with progressive disease on or off therapy. The HIV-specific CD4(+) T-cell responses in LTNP and patients on therapy were similar in frequency, phenotype, and cytokine production to responses directed against adenovirus, EBV, influenza virus, and VZV. HIV-specific CD4(+) T cells from patients off antiretroviral therapy demonstrated a shift towards a CCR7(−) CD45RA(−) phenotype and a reduced percentage of IL-2-producing cells. The alterations in cytokine production during HIV viremia were found to be intrinsic to the HIV-specific CD4(+) T cells and caused a requirement for IL-2 supplied exogenously for proliferation to occur. These observations suggest that many previously described changes in HIV-specific CD4(+) T-cell function and phenotype are a consequence of high levels of antigen in viremic patients. In addition, defects in function and phenotype of HIV-specific CD4(+) T cells are not readily discernible in the context of antiretroviral therapy but rather are similar to responses to other viruses

Exploring Influencing Factors of Anxiety Improvement Following Mindfulness-Based Music Therapy in Young Adults with Cancer

The purpose of this secondary analysis was to explore physiological, psychological, and situational influencing factors that may affect the impact of a mindfulness-music therapy intervention on anxiety severity in young adults receiving cancer treatment. Young adults receiving cancer treatment for ≥ eight weeks were recruited from adult and pediatric oncology outpatient centers at Dana-Farber Cancer Institute. Participants were asked to attend up to four, in-person (offered virtually via Zoom video conference after the onset of the COVID-19 pandemic) 45-min mindfulness-based music therapy sessions over twelve weeks with a board-certified music therapist. Participants completed questionnaires about anxiety, stress, and other cancer treatment-related outcomes before and after participating in the intervention. Changes in anxiety (i.e., PROMIS Anxiety 4a) over time were compared among baseline physiological (e.g., age or sex), psychological (e.g., stress), and situational influencing (i.e., intervention delivery format) factors using Wilcoxon-rank sum tests. Thirty-one of the 37 enrolled participants completed the baseline and post-intervention measures and were eligible for inclusion in the secondary analysis. Results revealed that higher baseline physical functioning (median change = −6.65), anxiety (median change=-5.65), fatigue (median change = −5.6), sleep disturbance (median change = −5.6), female sex (median change = −5.15), or virtual intervention delivery (median change = −4.65) were potential physiological, psychological, or situational influencing factors associated with anxiety improvement following mindfulness-based music therapy. Additional investigation into physiological, psychological, or situational influencing factors associated with anxiety response will help to tailor the design of future mindfulness-music therapy interventions to decrease psychological distress and address the unique psychosocial concerns among young adults receiving cancer treatment. Trial Registration ClinicalTrials.gov Identifier: NCT0370922

Diminished Production of Monocyte Proinflammatory Cytokines during Human Immunodeficiency Virus Viremia Is Mediated by Type I Interferons

The effect of human immunodeficiency virus (HIV) infection and high-level HIV replication on the function of monocytes was investigated. HIV-positive patients had elevated levels of spontaneous production of some or all of the monocyte proinflammatory cytokines measured (interleukin-1β [IL-1β], IL-6, and tumor necrosis factor alpha [TNF-α]) compared to uninfected controls. In patients on therapy with high frequencies of monocytes producing proinflammatory cytokines, this frequency was diminished in the context of viremia during an interruption of therapy. Diminished production of proinflammatory cytokines during viremia was restored by culture with autologous CD4(+) T cells or monocytes from an on-therapy time point or lipopolysaccharide (LPS). Microarray analysis demonstrated that diminished monocyte production of proinflammatory cytokines was correlated with elevated type I interferon-stimulated gene transcripts. The addition of exogenous alpha 2A interferon diminished the spontaneous production of IL-1β, IL-6, and TNF-α but did not affect responses to LPS, recapitulating the changes observed for HIV-viremic patients. These results suggest that monocyte function is diminished during high-level HIV viremia and that this effect is mediated by chronic stimulation by type I interferons. This effect on monocytes during viremia may play a role in diminished innate or adaptive immune system functions in HIV-infected patients. In addition, the restoration of these functions may also play a role in some immune reconstitution syndromes observed during initiation of therapy