Transcriptome Profiling Reveals Distinct Alterations in B-Cell Signature and Dysregulation of Peripheral B-Cell Subsets in Sickle Cell Anemia Patients.

INTRODUCTION: Sickle cell anemia (SCA) is characterized by immune system activation and heightened susceptibility to infections. We hypothesized that SCA patients exhibit transcriptional alterations in B-cell-related genes, impacting their peripheral B-cell compartment and leading to dysregulated humoral immunity and increased infection susceptibility. OBJECTIVE: Our objective was to conduct an in-silico analysis of whole blood transcriptomes from SCA patients and healthy controls obtained from public repositories. We aimed to identify alterations in the adaptive immune system and validate these findings in our own SCA patient cohort. METHODS: Bioinformatic analyses unveiled significant transcriptional alterations in B-cell signatures, developmental pathways, and signaling pathways. These results were validated in peripheral blood mononuclear cells from our SCA patient cohort and controls using real-time PCR and flow cytometry. RESULTS: Ninety genes exhibited differential expression, with 70 upregulated and 20 downregulated. Dysregulation in the B-cell compartment of SCA patients was evident, characterized by increased frequencies of immature and naive B-cells and decreased percentages of memory B-cell subsets compared to healthy controls. CONCLUSION: Our findings highlight previously unexplored transcriptional and quantitative alterations in peripheral B-cells among SCA patients. Understanding these changes sheds light on the mechanisms contributing to the heightened infection risk in this population. Future studies should delve deeper into these molecular changes to develop targeted interventions and therapeutic strategies aimed at mitigating infection susceptibility in individuals with SCA.

Potency and efficacy of pharmacological PIP4K2 inhibitors in acute lymphoblastic leukemia.

Acute lymphoblastic leukemia (ALL), a complex malignancy, displays varying expression profiles of PIP4K2-related genes in adult patients. While PIP4K2A expression is elevated in ALL bone marrow cells compared to healthy bone marrow cells, PIP4K2B is downregulated, and PIP4K2C remains relatively unchanged. Despite the correlation between increased PIP4K2A expression and increased percentage of peripheral blood blasts, clinical outcomes do not strongly correlate with the expression of these genes. Here we investigated the therapeutic potential of three PIP4K2 inhibitors (THZ-P1-2, a131, and CC260) in ALL cell models. THZ-P1-2 emerges as the most effective inhibitor, inducing cell death and mitochondrial damage while reducing cell viability and metabolism significantly. Comparative analyses highlight the superior efficacy of THZ-P1-2 over a131 and CC260. Notably, THZ-P1-2 uniquely disrupts autophagic flux and inhibits the PI3K/AKT/mTOR pathway, indicating a distinct molecular mechanism. In summary, our findings elucidate the differential expression of PIP4K2-related genes in ALL and underscore the potential role of PIP4K2A in disease pathogenesis. The therapeutic promise of THZ-P1-2 in ALL treatment, along with its distinct effects on cell death mechanisms and signaling pathways, enriches our understanding of PIP4K2's involvement in ALL development and offers targeted therapy prospects.

Cyclopenta[b]indoles as novel antimicrotubule agents with antileukemia activity.

Acute leukemias present therapeutic challenges despite advances in treatments. Microtubule inhibitors have played a pivotal role in cancer therapy, inspiring exploration into novel compounds like C2E1 from the cyclopenta[b]indole class. In the present study, we investigated C2E1's potential as a therapeutic agent for acute leukemia at molecular, cellular, and genetic levels. C2E1 demonstrated tubulin depolarization activity, significantly reducing leukemia cell viability. Its impact involved multifaceted mechanisms: inducing apoptosis, arrest of cell cycle progression, and inhibition of clonogenicity and migration in leukemia cells. At a molecular level, C2E1 triggered DNA damage, antiproliferative, and apoptosis markers and altered gene expression related to cytoskeletal regulation, disrupting essential cellular processes crucial for leukemia cell survival and proliferation. These findings highlight C2E1's promise as a potential candidate for novel anti-cancer therapies. Notably, its distinct mode of action from conventional microtubule-targeting drugs suggests the potential to bypass common resistance mechanisms encountered with existing treatments. In summary, C2E1 emerges as a compelling compound with diverse effects on leukemia cells, showcasing promising antineoplastic properties. Its ability to disrupt critical cellular functions selective to leukemia cells positions it as a candidate for future therapeutic development.

NT157 exhibits antineoplastic effects by targeting IRS and STAT3/5 signaling in multiple myeloma.

Multiple myeloma (MM) is a prevalent hematological malignancy with high recurrence and no definitive cure. The current study revisits the role of the IGF1/IGF1R axis in MM, introducing a novel inhibitor, NT157. The IGF1/IGF1R pathway is pivotal in MM, influencing cell survival, proliferation, and migration and impacting patient survival outcomes. NT157 targets intracellular proteins such as IRS and STAT proteins and demonstrates antineoplastic potential in hematological malignancies and solid tumors. In the present study, we assessed IGF1R signaling-related gene expression in MM patients and healthy donors, unveiling significant distinctions. MM cell lines displayed varying expression patterns of IGF1R-related proteins. A gene dependence analysis indicated the importance of targeting receptor and intracellular elements over autocrine IGF1. NT157 exhibited inhibitory effects on MM cell viability, clonal growth, cell cycle progression, and survival. Moreover, NT157 reduced IRS2 expression and STAT3, STAT5, and RPS6 activation and modulated oncogenes and tumor suppressors, fostering a tumor-suppressive molecular profile. In summary, our study demonstrates that the IGF1/IGF1R/IRS signaling axis is differentially activated in MM cells and the NT157's capacity to modulate crucial molecular targets, promoting antiproliferative effects and apoptosis in MM cells. NT157 may offer a multifaceted approach to enhance MM therapy.

Comprehensive analysis of the HCK gene in myeloid neoplasms: Insights into biological functions, prognosis, and response to antineoplastic agents.

Myeloid neoplasms result from molecular alterations in hematopoietic stem cells, with acute myeloid leukemia (AML) being one of the most aggressive and with a poor prognosis. Hematopoietic cell kinase (HCK) is a proto-oncogene that encodes a protein-tyrosine kinase of the Scr family, and it is highly expressed in AML. The present study investigated HCK expression in normal hematopoietic cells across myeloid differentiation stages and myeloid neoplasm patients. Within the AML cohort, we explored the impact of HCK expression on clinical outcomes and its correlation with clinical, genetic, and laboratory characteristics. Furthermore, we evaluated the association between HCK expression and the response to antineoplastic agents using ex vivo assay data from AML patients. HCK expression is higher in differentiated subpopulations of myeloid cells. High HCK expression was observed in patients with chronic myelomonocytic leukemia, chronic myeloid leukemia, and AML. In patients with AML, high levels of HCK negatively impacted overall and disease-free survival. High HCK expression was also associated with worse molecular risk groups and white blood cell count; however, it was not an independent prognostic factor. In functional genomic analyses, high HCK expression was associated with several biological and molecular processes relevant to leukemogenesis. HCK expression was also associated with sensitivity and resistance to several drugs currently used in the clinic. In conclusion, our analysis confirmed the differential expression of HCK in myeloid neoplasms and its potential association with unfavorable molecular risks in AML. We also provide new insights into HCK biological functions, prognosis, and response to antineoplastic agents.

Antineoplastic effects of pharmacological inhibitors of aurora kinases in CSF3RT618I-driven cells.

Myeloproliferative neoplasms (MPN) are consolidated as a relevant group of diseases derived from the malfunction of the hematopoiesis process and have as a particular attribute the increased proliferation of myeloid lineage. Among these, chronic neutrophilic leukemia (CNL) is distinguished, caused by the T618I mutation of the CSF3R gene, a trait that generates ligand-independent receptor activation and downstream JAK2/STAT signaling. Previous studies reported that mutations in BCR::ABL1 and JAK2V617F increased the expression of the aurora kinase A (AURKA) and B (AURKB) in Ba/F3 cells and their pharmacological inhibition displays antineoplastic effects in human BCR::ABL1 and JAK2V617F positive cells. Delimiting the current scenario, aspects related to the AURKA and AURKB as a potential target in CSF3RT618I-driven models is little known. In the present study, the cellular and molecular effects of pharmacological inhibitors of aurora kinases, such as aurora A inhibitor I, AZD1152-HQPA, and reversine, were evaluated in Ba/F3 expressing the CSF3RT618I mutation. AZD1152-HQPA and reversine demonstrated antineoplastic potential, causing a decrease in cell viability, clonogenicity, and proliferative capacity. At molecular levels, all inhibitors reduced histone H3 phosphorylation, aurora A inhibitor I and reversine reduced STAT5 phosphorylation, and AZD1152-HQPA and reversine induced PARP1 cleavage and γH2AX expression. Reversine more efficiently modulated genes associated with cell cycle and apoptosis compared to other drugs. In summary, our findings shed new insights into the use of AURKB inhibitors in the context of CNL.

Pharmacological Inhibition of PIP4K2 Potentiates Venetoclax-Induced Apoptosis in Acute Myeloid Leukemia.

Phosphatidylinositol-5-phosphate 4-kinase type 2 (PIP4K2) protein family members (PIP4K2A, PIP4K2B, and PIP4K2C) participate in the generation of PIP4,5P2, which acts as a secondary messenger in signal transduction, a substrate for metabolic processes, and has structural functions. In patients with acute myeloid leukemia (AML), high PIP4K2A and PIP4K2C levels are independent markers of a worse prognosis. Recently, our research group reported that THZ-P1-2 (PIP4K2 pan-inhibitor) exhibits anti-leukemic activity by disrupting mitochondrial homeostasis and autophagy in AML models. In the present study, we characterized the expression of PIP4K2 in the myeloid compartment of hematopoietic cells, as well as in AML cell lines and clinical samples with different genetic abnormalities. In ex vivo assays, PIP4K2 expression levels were related to sensitivity and resistance to several antileukemia drugs and highlighted the association between high PIP4K2A levels and resistance to venetoclax. The combination of THZ-P1-2 and venetoclax showed potentiating effects in reducing viability and inducing apoptosis in AML cells. A combined treatment differentially modulated multiple genes, including TAp73, BCL2, MCL1, and BCL2A1. In summary, our study identified the correlation between the expression of PIP4K2 and the response to antineoplastic agents in ex vivo assays in AML and exposed vulnerabilities that may be exploited in combined therapies, which could result in better therapeutic responses.

The Multikinase Inhibitor AD80 Induces Mitotic Catastrophe and Autophagy in Pancreatic Cancer Cells.

Significant advances in understanding the molecular complexity of the development and progression of pancreatic cancer have been made, but this disease is still considered one of the most lethal human cancers and needs new therapeutic options. In the present study, the antineoplastic effects of AD80, a multikinase inhibitor, were investigated in models of pancreatic cancer. AD80 reduced cell viability and clonogenicity and induced polyploidy in pancreatic cancer cells. At the molecular level, AD80 reduced RPS6 and histone H3 phosphorylation and induced γH2AX and PARP1 cleavage. Additionally, the drug markedly decreased AURKA phosphorylation and expression. In PANC-1 cells, AD80 strongly induced autophagic flux (consumption of LC3B and SQSTM1/p62). AD80 modulated 32 out of 84 autophagy-related genes and was associated with vacuole organization, macroautophagy, response to starvation, cellular response to nitrogen levels, and cellular response to extracellular stimulus. In 3D pancreatic cancer models, AD80 also effectively reduced growth independent of anchorage and cell viability. In summary, AD80 induces mitotic aberrations, DNA damage, autophagy, and apoptosis in pancreatic cancer cells. Our exploratory study establishes novel targets underlying the antineoplastic activity of the drug and provides insights into the development of therapeutic strategies for this disease.

2-Methoxyestradiol-3,17-O,O-bis-sulfamate (STX140) Inhibits Proliferation and Invasion via Senescence Pathway Induction in Human BRAFi-Resistant Melanoma Cells.

The endogenous estradiol derivative 2-Methoxyestradiol (2-ME) has shown good and wide anticancer activity but suffers from poor oral bioavailability and extensive metabolic conjugation. However, its sulfamoylated derivative, 2-methoxyestradiol-3,17-O,O-bis-sulfamate (STX140), has superior potential as a therapeutic agent, acts by disrupting microtubule polymerization, leading to cell cycle arrest and apoptosis in cancer cells and possesses much better pharmaceutical properties. This study investigated the antiproliferative and anti-invasive activities of STX140 in both SKMEL-28 naïve melanoma (SKMEL28-P) cells and resistant melanoma cells (SKMEL-28R). STX140 inhibited cell proliferation in the nanomolar range while having a less pronounced effect on human melanocytes. Additionally, STX140 induced cell cycle arrest in the G2/M phase and sub-G1, reduced migration, and clonogenic potential in monolayer models, and inhibited invasion in a 3D human skin model with melanoma cells. Furthermore, STX140 induced senescence features in melanoma and activated the senescence machinery by upregulating the expression of senescence genes and proteins related to senescence signaling. These findings suggest that STX140 may hold potential as a therapeutic agent for melanoma treatment.

Cellular and Molecular Effects of Eribulin in Preclinical Models of Hematologic Neoplasms.

Despite the advances in understanding the biology of hematologic neoplasms which has resulted in the approval of new drugs, the therapeutic options are still scarce for relapsed/refractory patients. Eribulin is a unique microtubule inhibitor that is currently being used in the therapy for metastatic breast cancer and soft tissue tumors. Here, we uncover eribulin's cellular and molecular effects in a molecularly heterogeneous panel of hematologic neoplasms. Eribulin reduced cell viability and clonogenicity and promoted apoptosis and cell cycle arrest. The minimal effects of eribulin observed in the normal leukocytes suggested selectivity for malignant blood cells. In the molecular scenario, eribulin induces DNA damage and apoptosis markers. The ABCB1, ABCC1, p-AKT, p-NFκB, and NFκB levels were associated with responsiveness to eribulin in blood cancer cells, and a resistance eribulin-related target score was constructed. Combining eribulin with elacridar (a P-glycoprotein inhibitor), but not with PDTC (an NFkB inhibitor), increases eribulin-induced apoptosis in leukemia cells. In conclusion, our data indicate that eribulin leads to mitotic catastrophe and cell death in blood cancer cells. The expression and activation of MDR1, PI3K/AKT, and the NFκB-related targets may be biomarkers of the eribulin response, and the combined treatment of eribulin and elacridar may overcome drug resistance in these diseases.

The PIP4K2 inhibitor THZ-P1-2 exhibits antileukemia activity by disruption of mitochondrial homeostasis and autophagy.

The treatment of acute leukemia is challenging because of the genetic heterogeneity between and within patients. Leukemic stem cells (LSCs) are relatively drug-resistant and frequently relapse. Their plasticity and capacity to adapt to extracellular stress, in which mitochondrial metabolism and autophagy play important roles, further complicates treatment. Genetic models of phosphatidylinositol-5-phosphate 4-kinase type 2 protein (PIP4K2s) inhibition have demonstrated the relevance of these enzymes in mitochondrial homeostasis and autophagic flux. Here, we uncovered the cellular and molecular effects of THZ-P1-2, a pan-inhibitor of PIP4K2s, in acute leukemia cells. THZ-P1-2 reduced cell viability and induced DNA damage, apoptosis, loss of mitochondrial membrane potential, and the accumulation of acidic vesicular organelles. Protein expression analysis revealed that THZ-P1-2 impaired autophagic flux. In addition, THZ-P1-2 induced cell differentiation and showed synergistic effects with venetoclax. In primary leukemia cells, LC-MS/MS-based proteome analysis revealed that sensitivity to THZ-P1-2 is associated with mitochondrial metabolism, cell cycle, cell-of-origin (hematopoietic stem cell and myeloid progenitor), and the TP53 pathway. The minimal effects of THZ-P1-2 observed in healthy CD34+ cells suggest a favorable therapeutic window. Our study provides insights into the pharmacological inhibition of PIP4K2s targeting mitochondrial homeostasis and autophagy, shedding light on a new class of drugs for acute leukemia.

NT157 exerts antineoplastic activity by targeting JNK and AXL signaling in lung cancer cells.

Combination therapies or multi-targeted drugs have been pointed out as an option to prevent the emergence of resistant clones, which could make long-term treatment more effective and translate into better clinical outcomes for cancer patients. The NT157 compound is a synthetic tyrphostin that leads to long-term inhibition of IGF1R/IRS1-2-, STAT3- and AXL-mediated signaling pathways. Given the importance of these signaling pathways for the development and progression of lung cancer, this disease becomes an interesting model for generating preclinical evidence on the cellular and molecular mechanisms underlying the antineoplastic activity of NT157. In lung cancer cells, exposure to NT157 decreased, in a dose-dependent manner, cell viability, clonogenicity, cell cycle progression and migration, and induced apoptosis (p < 0.05). In the molecular scenario, NT157 reduced expression of IRS1 and AXL and phosphorylation of p38 MAPK, AKT, and 4EBP1. Besides, NT157 decreased expression of oncogenes BCL2, CCND1, MYB, and MYC and increased genes related to cellular stress and apoptosis, JUN, BBC3, CDKN1A, CDKN1B, FOS, and EGR1 (p < 0.05), favoring a tumor-suppressive cell signaling network in the context of lung cancer. Of note, JNK was identified as a key kinase for NT157-induced IRS1 and IRS2 phosphorylation, revealing a novel axis involved in the mechanism of action of the drug. NT157 also presented potentiating effects on EGFR inhibitors in lung cancer cells. In conclusion, our preclinical findings highlight NT157 as a putative prototype of a multitarget drug that may contribute to the antineoplastic arsenal against lung cancer.

Allogeneic haematopoietic stem cell transplantation resets T- and B-cell compartments in sickle cell disease patients.

Objectives: Allogeneic haematopoietic stem cell transplantation (allo-HSCT) is the only currently available curative treatment for sickle cell disease (SCD). Here, we comprehensively evaluated the reconstitution of T- and B-cell compartments in 29 SCD patients treated with allo-HSCT and how it correlated with the development of acute graft-versus-host disease (aGvHD). Methods: T-cell neogenesis was assessed by quantification of signal-joint and ß-chain TCR excision circles. B-cell neogenesis was evaluated by quantification of signal-joint and coding-joint K-chain recombination excision circles. T- and B-cell peripheral subset numbers were assessed by flow cytometry. Results: Before allo-HSCT (baseline), T-cell neogenesis was normal in SCD patients compared with age-, gender- and ethnicity-matched healthy controls. Following allo-HSCT, T-cell neogenesis declined but was fully restored to healthy control levels at one year post-transplantation. Peripheral T-cell subset counts were fully restored only at 24 months post-transplantation. Occurrence of acute graft-versus-host disease (aGvHD) transiently affected T- and B-cell neogenesis and overall reconstitution of T- and B-cell peripheral subsets. B-cell neogenesis was significantly higher in SCD patients at baseline than in healthy controls, remaining high throughout the follow-up after allo-HSCT. Notably, after transplantation SCD patients showed increased frequencies of IL-10-producing B-regulatory cells and IgM+ memory B-cell subsets compared with baseline levels and with healthy controls. Conclusion: Our findings revealed that the T- and B-cell compartments were normally reconstituted in SCD patients after allo-HSCT. In addition, the increase of IL-10-producing B-regulatory cells may contribute to improve immune regulation and homeostasis after transplantation.

NSC305787, a pharmacological ezrin inhibitor, exhibits antineoplastic activity in pancreatic cancer cells.

Pancreatic cancer is one of the most lethal human neoplasms, and despite advances in the understanding of the molecular complexity involved in the development and progression of this disease, little of this new information has been translated into improvements in therapy and prognosis. Ezrin (EZR) is a protein that regulates multiple cellular functions, including cell proliferation, survival, morphogenesis, adhesion, and motility. In pancreatic cancer, EZR is highly expressed and reflects an unfavorable prognosis, whereas EZR silencing ameliorates the malignant phenotype of pancreatic cancer cells. NSC305787 was identified as a pharmacological EZR inhibitor with favorable pharmacokinetics and antineoplastic activity. Here, we endeavored to investigate the impact of EZR expression on survival outcomes and its associations with molecular and biological characteristics in The Cancer Genome Atlas pancreatic adenocarcinoma cohort. We also assessed the potential antineoplastic effects of NSC305787 in pancreatic cancer cell lines. High EZR expression was an independent predictor of worse survival outcomes. Functional genomics analysis indicated that EZR contributes to multiple cancer-related pathways, including PI3K/AKT/mTOR signaling, NOTCH signaling, estrogen-mediated signaling, and apoptosis. In pancreatic cells, NSC305787 reduced cell viability, clonal growth, and migration. Our exploratory molecular studies identified that NSC305787 modulates the expression and activation of key regulators of the cell cycle, proliferation, DNA damage, and apoptosis, favoring a tumor-suppressive molecular network. In conclusion, EZR expression is an independent prognosis marker in pancreatic cancer. Our study identifies a novel molecular axis underlying the antineoplastic activity of NSC305787 and provides insights into the development of therapeutic strategies for pancreatic cancer.

Effect of FKBP12-Derived Intracellular Peptides on Rapamycin-Induced FKBP-FRB Interaction and Autophagy.

Intracellular peptides (InPeps) generated by proteasomes were previously suggested as putative natural regulators of protein-protein interactions (PPI). Here, the main aim was to investigate the intracellular effects of intracellular peptide VFDVELL (VFD7) and related peptides on PPI. The internalization of the peptides was achieved using a C-terminus covalently bound cell-penetrating peptide (cpp; YGRKKRRQRRR). The possible inhibition of PPI was investigated using a NanoBiT® luciferase structural complementation reporter system, with a pair of plasmids vectors each encoding, simultaneously, either FK506-binding protein (FKBP) or FKBP-binding domain (FRB) of mechanistic target of rapamycin complex 1 (mTORC1). The interaction of FKBP-FRB within cells occurs under rapamycin induction. Results shown that rapamycin-induced interaction between FKBP-FRB within human embryonic kidney 293 (HEK293) cells was inhibited by VFD7-cpp (10-500 nM) and FDVELLYGRKKRRQRRR (VFD6-cpp; 1-500 nM); additional VFD7-cpp derivatives were either less or not effective in inhibiting FKBP-FRB interaction induced by rapamycin. Molecular dynamics simulations suggested that selected peptides, such as VFD7-cpp, VFD6-cpp, VFAVELLYGRKKKRRQRRR (VFA7-cpp), and VFEVELLYGRKKKRRQRRR (VFA7-cpp), bind to FKBP and to FRB protein surfaces. However, only VFD7-cpp and VFD6-cpp induced changes on FKBP structure, which could help with understanding their mechanism of PPI inhibition. InPeps extracted from HEK293 cells were found mainly associated with macromolecular components (i.e., proteins and/or nucleic acids), contributing to understanding InPeps' intracellular proteolytic stability and mechanism of action-inhibiting PPI within cells. In a model of cell death induced by hypoxia-reoxygenation, VFD6-cpp (1 µM) increased the viability of mouse embryonic fibroblasts cells (MEF) expressing mTORC1-regulated autophagy-related gene 5 (Atg5), but not in autophagy-deficient MEF cells lacking the expression of Atg5. These data suggest that VFD6-cpp could have therapeutic applications reducing undesired side effects of rapamycin long-term treatments. In summary, the present report provides further evidence that InPeps have biological significance and could be valuable tools for the rational design of therapeutic molecules targeting intracellular PPI.