ABSTRACT
The BCL2-inhibitor, Venetoclax (VEN), has shown significant anti-leukemic efficacy in combination with the DNMT-inhibitor, Azacytidine (AZA). To explore the mechanisms underlying the selective sensitivity of mutant leukemia cells to VEN and AZA, we used cell-based isogenic models containing a common leukemia-associated mutation in the epigenetic regulator ASXL1. KBM5 cells with CRISPR/Cas9-mediated correction of the ASXL1G710X mutation showed reduced leukemic growth, increased myeloid differentiation, and decreased HOXA and BCL2 gene expression in vitro compared to uncorrected KBM5 cells. Increased expression of the anti-apoptotic gene, BCL2, was also observed in bone marrow CD34+ cells from ASXL1 mutant MDS patients compared to CD34+ cells from wild-type MDS cases. ATAC-sequencing demonstrated open chromatin at the BCL2 promoter in the ASXL1 mutant KBM5 cells. BH3 profiling demonstrated increased dependence of mutant cells on BCL2. Upon treatment with VEN, mutant cells demonstrated increased growth inhibition. In addition, genome-wide methylome analysis of primary MDS samples and isogenic cell lines demonstrated increased gene-body methylation in ASXL1 mutant cells, with consequently increased sensitivity to AZA. These data mechanistically link the common leukemia-associated mutation ASXL1 to enhanced sensitivity to VEN and AZA via epigenetic upregulation of BCL2 expression and widespread alterations in DNA methylation.
Subject(s)
Antineoplastic Agents/pharmacology , Azacitidine/pharmacology , Bridged Bicyclo Compounds, Heterocyclic/pharmacology , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics , Repressor Proteins/genetics , Sulfonamides/pharmacology , Cell Line, Tumor , Epigenesis, Genetic/drug effects , Gene Expression Regulation, Leukemic/drug effects , Humans , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy , Mutation/drug effects , Point Mutation/drug effectsSubject(s)
Coronavirus Infections/epidemiology , Critical Illness/therapy , Hospital Mortality , Hospitals, Pediatric/organization & administration , Palliative Care/methods , Pneumonia, Viral/epidemiology , Adult , COVID-19 , COVID-19 Testing , Child , Child, Preschool , Clinical Laboratory Techniques , Coronavirus Infections/diagnosis , Female , Hospitalization/statistics & numerical data , Humans , Infant , Male , Medical Staff, Hospital/education , New York City , Palliative Care/statistics & numerical data , Pandemics , Patient Care Team/organization & administration , Pediatrics/organization & administration , Pneumonia, Viral/diagnosis , Risk AssessmentABSTRACT
An 8-year-old boy with no significant past medical history presented to his pediatrician with 5 days of fever, diffuse abdominal pain, and pallor. The pediatrician referred the patient to the emergency department (ED), out of concern for possible malignancy. Initial vital signs indicated fever, tachypnea, and tachycardia. Physical examination was significant for marked abdominal distension, hepatosplenomegaly, and abdominal tenderness in the right upper and lower quadrants. Initial laboratory studies were notable for pancytopenia as well as an elevated erythrocyte sedimentation rate and C-reactive protein. Computed tomography (CT) of the abdomen and pelvis showed massive splenomegaly. The only significant history of travel was immigration from Albania 10 months before admission. The patient was admitted to a tertiary care children's hospital and was evaluated by hematology-oncology, infectious disease, genetics, and rheumatology subspecialty teams. Our multidisciplinary panel of experts will discuss the evaluation of pancytopenia with apparent multiorgan involvement and the diagnosis and appropriate management of a rare disease.
Subject(s)
Fever/diagnosis , Leishmaniasis, Visceral/complications , Pancytopenia/diagnosis , Splenomegaly/diagnosis , Child , Diagnosis, Differential , Fever/etiology , Humans , Leishmania/isolation & purification , Leishmaniasis, Visceral/diagnosis , Male , Pancytopenia/etiology , Splenomegaly/etiology , Tomography, X-Ray ComputedABSTRACT
OBJECTIVE: To evaluate the effect of bisphenol-A (BPA), a xenoestrogen endocrine disruptor, on endometrial P receptor (PR) expression in nonhuman primates and human cells. DESIGN: Controlled trial in primates. SETTING: University. ANIMAL(S): African green monkeys. INTERVENTION(S): After oophorectomy, BPA (50 µg/kg/d), E(2), both, or vehicle control were administered. Estradiol and BPA were used in Ishikawa cells. MAIN OUTCOME MEASURE(S): Progesterone receptor expression using immunohistochemistry and quantitative polymerase chain reaction. RESULT(S): Progesterone receptor expression was increased in E(2)-treated primates compared with controls. Exposure to the combination of E(2) and BPA resulted in decreased PR expression compared with E(2) exposure alone. In Ishikawa cells treated with E(2), PR expression increased 5.1-fold; however, when Ishikawa cells were simultaneously treated with E(2) and BPA, PR expression was decreased to 0.6-fold that of cells treated with E(2) alone. CONCLUSION(S): Bisphenol-A alone functions as a weak estrogen. However, when administered with E(2), BPA diminishes E(2)-induced PR expression. The estrogen-like effect of BPA reported in exposed humans may be mediated by PR blockade and a resultant decrease in the estrogen inhibition normally imparted by P. Diminished PR expression may underlie previous reports linking BPA exposure to endometrial dysfunction in humans.
