Biology subjects

Chernyavskaya, Y.

Publications and source records attributed to Chernyavskaya, Y..

4 recordsLinked to original sources

bioRxiv2026

NHE1 sustains leukemia-propagating capacity and mitochondrial fitness in T-cell acute lymphoblastic leukemia

Leukemia-propagating cells (LPCs) sustain T-cell acute lymphoblastic leukemia (T-ALL) and are thought to contribute to disease progression and relapse. However, the lack of reliable LPC markers has hindered efforts to identify their vulnerabilities. We screened 786 FDA-approved compounds using a zebrafish transplantation assay that directly measures leukemia-propagating activity. Amiloride markedly reduced functional LPC frequency (p < 0.0001) without significantly delaying leukemia onset at higher transplantation doses. Because amiloride inhibits the sodium-hydrogen exchanger NHE1, we investigated its role in T-ALL. NHE1 knockdown reduced self-renewal-associated colony formation by >70% human T-ALL cells, with only modest increases in apoptosis. Transcriptomic and proteomic analyses revealed extensive molecular remodeling, including reduced abundance of proteins involved in mitochondrial respiration and translation. Amiloride treatment and NHE1 knockdown impaired mitochondrial respiration and reduced mitochondrial content, while NHE1 knockdown also decreased mitochondrial membrane potential. Metabolomic profiling revealed alterations in TCA cycle intermediates and broader cellular metabolism. In mouse xenografts, NHE1 knockdown reduced leukemia involvement in the bone marrow and spleen despite similar overall leukemia progression and survival. Together, these findings implicate NHE1 as a previously unrecognized regulator of T-ALL leukemia-propagating activity, reveal unexpected contributions of this ion exchanger to mitochondrial fitness and leukemia involvement in hematopoietic tissues, and support further investigation of NHE1 as a potential therapeutic target in T-ALL.

cancer biology↗

bioRxiv2025

Small Extracellular Vesicles from Radioresistant H3K27M-Pediatric Diffuse Midline Glioma Cells Modulate Tumor Phenotypes and Radiation Response

Pediatric diffuse midline gliomas with the Histone 3 lysine 27-to-methionine mutation (H3K27M-pDMG) are aggressive brain tumors characterized by intrinsic resistance to radiation therapy, the current standard of care. These tumors exhibit significant intratumoral heterogeneity, with distinct subclonal populations likely contributing to therapy resistance. Emerging evidence suggests that small extracellular vesicles (sEV) mediate oncogenic signaling within glioma stem cell populations, yet their role under radiation-induced stress remains poorly understood. In this study, we characterized sEV uptake dynamics among H3K27M-pDMG tumor cells, identified key sEV surface proteins, and demonstrated that sEVs derived from radioresistant (RR) H3K27M-pDMG cells confer radioprotective effects on radiosensitive tumor cells. Molecular profiling revealed that RR-sEVs carry proteins, microRNAs (miRNAs), and metabolites associated with glycolysis, oxidative phosphorylation, and DNA repair. Upon uptake, RR-sEVs reprogrammed recipient cells by altering gene expression and metabolic pathways, and enhancing DNA repair and survival following radiation exposure. These findings provide insights into the role of sEV-mediated intratumoral communication as a contributor to radiation resistance in H3K27M-pDMG and suggest potential therapeutic strategies to disrupt this process and enhance radiation efficacy.

cancer biology↗

bioRxiv2021

Nanopore sequencing methods detect cell-free DNA associated with minimal residual disease and central nervous system infiltration in pediatric Acute Lymphoblastic Leukemia

Acute Lymphoblastic Leukemia (ALL) patients that are positive for minimal residual disease (MRD) after therapy or have leukemic infiltration into the central nervous system (CNS) are considered high risk and receive intensive chemotherapy regimens. Current methods to diagnose MRD and CNS infiltration rely on detecting leukemic cells in patient samples using pathology, flow cytometry, or next-generation sequencing. However, leukemic blasts may persist in the patient but not be physically present in bone marrow biopsy or biofluid sample, leading to inaccurate or delayed patient diagnosis. We have developed a nanopore sequencing workflow to detect B-ALL-associated cell-free DNA (cfDNA) in blood and cerebrospinal fluid (CSF) samples. Quantitation of B-cell specific VDJ recombination events in cfDNA samples defined B-ALL clonal heterogeneity. This workflow allowed us to track the response of individual B-ALL clones throughout treatment. Detection of cfDNA also predicted the clinical diagnosis of MRD and CNS disease. Importantly, we identified patients diagnosed as CNS negative who had low B-cell derived cell-free DNA levels in their CSF sample that correlated with B-cell clones present in the bone marrow. These data suggest that cfDNA assays may be useful in detecting the presence of ALL in the patient even when blasts are not in the biofluid sample. Nanopore analysis of cell-free DNA is a simple, rapid, and inexpensive assay that can serve as a valuable complement to traditional clinical diagnostic approaches for ALL. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=50 SRC="FIGDIR/small/462067v2_ufig1.gif" ALT="Figure 1"> View larger version (12K): org.highwire.dtl.DTLVardef@1373bd3org.highwire.dtl.DTLVardef@138b2e3org.highwire.dtl.DTLVardef@168661forg.highwire.dtl.DTLVardef@1088626_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2021

Long-Read Sequencing of the Zebrafish Genome Reorganizes Genomic Architecture

Nanopore sequencing technology has revolutionized the field of genome biology with its ability to generate extra-long reads that can resolve regions of the genome that were previously inaccessible to short-read sequencing platforms. Although long-read sequencing has been used to resolve several vertebrate genomes, a nanopore-based zebrafish assembly has not yet been released. Over 50% of the zebrafish genome consists of difficult to map, highly repetitive, low complexity elements that pose inherent problems for short-read sequencers and assemblers. We used nanopore sequencing to improve upon and resolve the issues plaguing the current zebrafish reference assembly (GRCz11). Our long-read assembly improved the current resolution of the reference genome by identifying 1,697 novel insertions and deletions over 1Kb in length and placing 106 previously unlocalized scaffolds. We also discovered additional sites of retrotransposon integration previously unreported in GRCz11 and observed their expression in adult zebrafish under physiologic conditions, implying they have active mobility in the zebrafish genome and contribute to the ever-changing genomic landscape.

genomics↗