Publications by authors named "Lapalombella R"

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological malignancy with a poor prognosis and limited options for targeted therapies. Identifying new molecular targets to develop novel therapeutic strategies is the pressing immediate issue in T-ALL. Here, we observed high expression of WD Repeat-Containing Protein 5 (WDR5) in T-ALL; with in vitro and in vivo models we demonstrated the oncogenic role of WDR5 in T-ALL by activating cell cycle signaling through its new downstream effector, ATPase family AAA domain-containing 2 (ATAD2).

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  • The nuclear export receptor XPO1 is commonly overexpressed in cancer cells, leading to mislocalization of important proteins; the inhibitor selinexor reverses this effect by blocking XPO1-cargo binding.
  • Selinexor triggers the degradation of XPO1 through a specific mechanism involving the cullin-RING E3 ubiquitin ligase (CRL) system and its substrate receptor ASB8.
  • Research using cryogenic electron microscopy revealed that selinexor stabilizes XPO1 in a unique conformation, allowing ASB8 to bind effectively and facilitate ubiquitination, showcasing a new method of protein degradation that differs from previously known molecular glue strategies.
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Acute myeloid leukemia (AML) is the most common and lethal leukemia in adults. AML consists of many genetic subtypes, which limits broad applicability of targeted therapy. We discovered that the hematopoiesis-restricted tetraspanin CD37 is expressed on the majority of primary AML blasts and thus may represent a common therapeutic target for AML regardless of subtype.

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Patients with chronic lymphocytic leukemia (CLL) respond well to initial treatment with the B-cell lymphoma 2 (BCL2) inhibitor venetoclax. Upon relapse, they often retain sensitivity to BCL2 targeting, but durability of response remains a concern. We hypothesize that targeting both BCL2 and B-cell lymphoma-extra large (BCLXL) will be a successful strategy to treat CLL, including for patients who relapse on venetoclax.

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Acute myeloid leukemia (AML) is a highly aggressive hematologic cancer with poor survival across a broad range of molecular subtypes. Development of efficacious and well-tolerable therapies encompassing the range of mutations that can arise in AML remains an unmet need. The bromo- and extra-terminal domain (BET) family of proteins represents an attractive therapeutic target in AML due to their crucial roles in many cellular functions, regardless of any specific mutation.

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  • Myeloid neoplasms, which are linked to clonal hematopoiesis (CH), may also play a role in acute lymphoblastic leukemia (ALL), with 18% of adult ALL cases having TP53 mutations and 16% carrying myeloid CH-related mutations.
  • ALL associated with these myeloid mutations displays unique genetic traits and poorer survival outcomes, suggesting it is a high-risk disease.
  • Research indicates that myeloid mutations can develop years before an ALL diagnosis, with certain clones becoming dominant, while B-ALL cases respond better to immunotherapy due to alterations in cell survival genes.
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Mantle cell lymphoma (MCL) is an incurable B-cell malignancy that comprises up to 6% of non-Hodgkin lymphomas diagnosed annually and is associated with a poor prognosis. The average overall survival of patients with MCL is 5 years, and for most patients who progress on targeted agents, survival remains at a dismal 3 to 8 months. There is a major unmet need to identify new therapeutic approaches that are well tolerated to improve treatment outcomes and quality of life.

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  • Mantle cell lymphoma (MCL) is a challenging B-cell cancer with limited treatment options, especially for those who do not respond to targeted therapies.
  • PRMT5 is found to be overactive in MCL and contributes to cancer progression by altering key cellular processes.
  • Inhibiting PRMT5 with the drug PRT-382 shows promising results in blocking tumor growth and promoting cell death, suggesting it could be a potential treatment for MCL patients, especially those with certain genetic markers.
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Altered hematopoietic stem cell (HSC) fate underlies primary blood disorders but microenvironmental factors controlling this are poorly understood. Genetically barcoded genome editing of synthetic target arrays for lineage tracing (GESTALT) zebrafish were used to screen for factors expressed by the sinusoidal vascular niche that alter the phylogenetic distribution of the HSC pool under native conditions. Dysregulated expression of protein kinase C delta (PKC-δ, encoded by prkcda) increases the number of HSC clones by up to 80% and expands polyclonal populations of immature neutrophil and erythroid precursors.

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  • Richter's Transformation (RT) is a dangerous progression of chronic lymphocytic leukemia (CLL) that appears as diffuse large B-cell lymphoma, with a key role suspected for protein arginine methyltransferase 5 (PRMT5).
  • Research shows that PRMT5 is consistently overexpressed in patients developing RT and that mice with increased levels of PRMT5 face a higher death risk and develop aggressive B-cell diseases similar to RT.
  • The study also introduces PRT382, a new and selective inhibitor of PRMT5, suggesting its potential for targeted treatment in aggressive cases of CLL and RT, highlighting the need for clinical trials.
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Chronic lymphocytic leukemia (CLL) is effectively treated with targeted therapies including Bruton tyrosine kinase inhibitors and BCL2 antagonists. When these become ineffective, treatment options are limited. Positive transcription elongation factor complex (P-TEFb), a heterodimeric protein complex composed of cyclin dependent kinase 9 (CDK9) and cyclin T1, functions to regulate short half-life transcripts by phosphorylation of RNA Polymerase II (POLII).

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Chronic lymphocytic leukemia (CLL) is a quiescent B-cell malignancy that depends on transcriptional dysregulation for survival. The histone deacetylases are transcriptional regulators whose role within the regulatory chromatin and consequence on the CLL transcriptome is poorly characterized. Here, we profiled and integrated the genome-wide occupancy of HDAC1, BRD4, H3K27Ac, and H3K9Ac signals with chromatin accessibility, Pol2 occupancy, and target expression signatures in CLL cells.

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Using a genome-wide CRISPR screen, we identified , , and as synthetic lethal partners with gilteritinib treatment in fms-like tyrosine kinase 3 ()-internal tandem duplication (ITD) acute myeloid leukemia (AML) and genetically and pharmacologically validated their roles in gilteritinib sensitivity. The presence of -ITD is associated with an increase in anaerobic glycolysis, rendering leukemia cells highly sensitive to inhibition of glycolysis. Supportive of this, our data show the enrichment of single guide RNAs targeting 28 glycolysis-related genes upon gilteritinib treatment, suggesting that switching from glycolysis to oxidative phosphorylation (OXPHOS) may represent a metabolic adaption of AML in gilteritinib resistance.

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DNA origami (DO) nanotechnology enables the construction of precise nanostructures capable of functionalization with small molecule drugs, nucleic acids, and proteins, suggesting a promising platform for biomedical applications. Despite the potential for drug and vaccine delivery, the impact of DO vehicles on immunogenicity in vivo is not well understood. Here, two DO vehicles, a flat triangle and a nanorod, at varying concentrations are evaluated in vitro and with a repeated dosing regimen administered at a high dose in vivo to study early and late immunogenicity.

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Purpose: Dual blockade of Bruton's tyrosine kinase with ibrutinib and selinexor has potential to deepen responses for patients with chronic lymphocytic leukemia (CLL) and non-Hodgkin lymphoma (NHL).

Patients And Methods: In this phase I study (clinicaltrials.gov: NCT02303392), adult patients with CLL/NHL, relapsed/refractory to ≥1 prior therapy were enrolled.

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Dysregulated cellular differentiation is a hallmark of acute leukemogenesis. Phosphatases are widely suppressed in cancers but have not been traditionally associated with differentiation. In this study, we found that the silencing of protein phosphatase 2A (PP2A) directly blocks differentiation in acute myeloid leukemia (AML).

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Rare, recurrent balanced translocations occur in a variety of cancers but are often not functionally interrogated. Balanced translocations with the immunoglobulin heavy chain locus (IGH; 14q32) in chronic lymphocytic leukemia (CLL) are infrequent but have led to the discovery of pathogenic genes including CCND1, BCL2, and BCL3. Following identification of a t(X;14)(q28;q32) translocation that placed the mature T cell proliferation 1 gene (MTCP1) adjacent to the immunoglobulin locus in a CLL patient, we hypothesized that this gene may have previously unrecognized importance.

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The in vitro erythrocyte differentiation model remains a strong, clinically relevant tool to model erythroid development in normal and disease related hematopoiesis. This model also has application to developing therapeutics for diseases related to red blood cells such as sickle cell anemia where targeting increased expression of fetal hemoglobin has been a major emphasis. Since the original protocol's publication in 2002, many groups have published modified methodologies to address issues in efficiency of maturation and terminal enucleation, as well as in scalability.

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Acute myeloid leukemia (AML) with an internal tandem duplication (-ITD) mutation is an aggressive hematologic malignancy associated with frequent relapse and poor overall survival. The tyrosine kinase inhibitor gilteritinib is approved for the treatment of relapse/refractory AML with mutations, yet its mechanism of action is not completely understood. Here, we sought to identify additional therapeutic targets that can be exploited to enhance gilteritinib's antileukemic effect.

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Background: Tumor-specific metabolic processes essential for cell survival are promising targets to potentially circumvent intratumoral heterogeneity, a major resistance factor in gliomas. Tumor cells preferentially using nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in the salvage pathway for synthesis of NAD, a critical cofactor for diverse biological processes including cellular redox reactions, energy metabolism, and biosynthesis. NAMPT is overexpressed in most malignancies, including gliomas, and can serve as a tumor-specific target.

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Article Synopsis
  • KPT-9274 is a first-in-class inhibitor targeting both PAK4 and NAMPT, showing effectiveness against various types of acute myeloid leukemia (AML) by blocking NAD production.
  • In preclinical trials, the treatment revealed specific toxicities in mice, including stomach and kidney damage, as well as anemia, especially in female subjects due to EPO deficiency.
  • The study identified that niacin could alleviate kidney toxicity and EPO deficiency associated with KPT-9274 while maintaining its anti-cancer effectiveness, providing potential avenues for improving side effects of this therapy.
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Hematopoiesis is hierarchical, and it has been postulated that acute myeloid leukemia (AML) is organized similarly with leukemia stem cells (LSCs) residing at the apex. Limited cells acquired by fluorescence activated cell sorting in tandem with targeted amplicon-based sequencing (LC-FACSeq) enables identification of mutations in small subpopulations of cells, such as LSCs. Leveraging this, we studied clonal compositions of immunophenotypically-defined compartments in AML through genomic and functional analyses at diagnosis, remission and relapse in 88 AML patients.

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The programmed death-1 (PD-1) and the PD ligand 1 (PD-L1) interaction represents a key immune checkpoint within the tumor microenvironment (TME), and PD-1 blockade has led to exciting therapeutic advances in clinical oncology. Although IFN-γ-dependent PD-L1 induction on tumor cells was initially thought to mediate the suppression on effector cells, recent studies have shown that PD-L1 is also expressed at high level on tumor-associated macrophages (TAMs) in certain types of tumors. However, the precise role of PD-L1 expression on TAMs in suppressing antitumor immunity within the TME remains to be defined.

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