The crosstalk between hematopoietic stem/progenitor cells (HSC), both normal and leukemic, and their neighboring bone marrow (BM) microenvironment (niche) creates a reciprocal dependency, a master regulator of biological process, and chemotherapy resistance. In acute myeloid leukemia (AML), leukemic stem/progenitor cells (LSC) anchored in the protective BM microenvironment, reprogram and transform this niche into a leukemia-supporting and chemoprotective environment. One most important player involved in this crosstalk are CXCL12, produced by the BM mesenchymal stromal cells, and its receptor CXCR4, present onto HSC. The downstream molecular mechanisms involved in CXCL12/CXCR4 axis have many targets, including the Src family members of non-receptor tyrosine kinase (SFK). We herein study the role of one SFK member, the Hematopoietic Cell Kinase (HCK), in CXCL12/CXCR4 pathway and its contribution to the AML pathogenesis. We verified that the inhibition of HCK severely impaired CXCL12-induced migration of leukemic cell lines and CD34 positive cells from AML patients bone marrow, through a disruption of the activation of CXCL12/CXCR4/PI3K/AKT and CXCL12/CXCR4/MAPK/ERK signaling, and by a decreased cytoskeleton dynamic through a lower rate of actin polymerization. We provide new insights into the key role of HCK in conferring a migratory advantage to leukemic cells thought CXCL12/CXCR4 axis. HCK represents an important protein of the main pathway involved in the crosstalk between HSC, and their surrounding milieu. Thus, HCK inhibition could represent a novel approach for the treatment of the acute myeloid leukemia.
<p><strong>Background:</strong> Multiple myeloma is characterized by abnormal plasmocytes proliferation in the bone marrow, resulting in an immunoglobulin oversecretion, which can cause bone pain, anemia, kidney dysfunction, and infections. The present study evaluates prognostic factors and the bone involvement in patients who had a confirmed diagnosis of MM.</p><p><strong>Methods:</strong> A retrospective study was conducted in hospital universitário São Francisco of Bragança Paulista. Patient demographic data, laboratory parameters and treatment received were recorded. We also analyzed the variables related to diagnosis and the development of bone lesions in MM patients.</p><p><strong>Results:</strong> A total of 42 patients had a confirmed diagnosis of MM, out of which most (54.76%) were older than 65. Most patients (45.24%) had beta-2-microglobulin values greater than 5.5 mcg/dl, indicating an advanced stage of the disease and consequently a less favorable prognosis. The main clinical manifestation observed was anemia in 61.90% (26/42) and bone lesions 59.52% (25/42). The analysis of imaging exams showed that most patients presented bone alterations, such as osteopenia, lytic lesions and fractures. Interestingly, 11.90% patients were submitted to autologous bone marrow transplantation with further remission of the disease. Bone marrow transplantation increases overall survival and disease-free survival when compared to conventional treatment.</p><p><strong>Conclusions:</strong> Since MM prognostic factors are numerous and, therefore, the understanding and analysis of the clinical and laboratory features of MM can contribute to an early diagnosis of patients, a targeted therapeutic approach and better outcomes.</p>
The bone marrow (BM) microenvironment (niche) is abnormally altered in acute myeloid leukemia (AML), leading to deficient secretion of proteins, soluble factors, and cytokines by mesenchymal stromal cells (MSC) that modifies the crosstalk between MSC and hematopoietic cells. We focused on a WNT gene/protein family member, WNT5A, which is downregulated in leukemia and correlated with disease progression and poor prognosis. We demonstrated that WNT5A protein upregulated the WNT non-canonical pathway only in leukemic cells, without modulating normal cell behavior. We also introduced a novel WNT5A-mimicking compound, Foxy-5. Our results showed reduction of crucial biological functions that are upregulated in leukemia cells, including ROS generation, cell proliferation, and autophagy, as well as G0/G1 cell cycle arrest. Additionally, Foxy-5 induced early-stage macrophage cell differentiation, a crucial process during leukemia development. At a molecular level, Foxy-5 led to the downregulation of two overexpressed leukemia pathways, PI3K and MAPK, which resulted in a disarrangement of actin polymerization with consequent impairment of CXCL12-induced chemotaxis. Notably, in a novel tri-dimensional bone marrow-mimicking model, Foxy-5 led to reduced leukemia cell growth and similar results were observed in a xenograft in vivo model. Overall, our findings highlight the pivotal role of WNT5A in leukemia and demonstrate that Foxy-5 acts as a specific antineoplastic agent in leukemia, counterbalancing several leukemic oncogenic processes related to the crosstalk in the bone marrow niche, and represents a promising therapeutic option for AML.
Introduction. Hematopoietic cell kinase (HCK) belongs to the Src kinase family (SFK) involved in the oncogenic process and hematological malignancy. Some SFK inhibitors are currently under investigation in clinical trials for leukemia after demonstrating efficacy in patients with solid tumors. We have previously reported that HCK is overexpressed in leukemic cells and its inhibition by lentivirus resulted in reduction of cell growth and increased cell death (Roversi et al. BBA Mol Basis Dis. 2017, 1863(2):450-61). In light of the genomic and molecular diversity of myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML), the development of chemical compounds specific for new molecular targets is currently an important subject. Aims. To investigate the in vitro and in vivo effects of a new chemical compound targeting HCK inhibition (iHCK), alone or in combination with the most used drugs for treatment of MDS and AML (Azacytidine - Aza - or Cytarabine - Ara-C). Methods. After iHCK development, we tested its activity alone or in combination with Aza or Ara-C in CD34+ cells isolated from AML patients (n=5) as well as in a panel of myeloid leukemia cell lines (KG1, HL-60, HEL and K562). Additionally, we tested the iHCK in normal and malignant cells cultured in a 3D bioscaffold obtained by decellularization of bovine bone marrow (Bianco et al. Biomat Sci 2019, 7(4):1516-28), in order to mimic the bone marrow niche. After informed written consent and approval of the Ethical Committee of University of Campinas (CAAE 1000.0.146.00-11), in accordance to the Helsinki Declaration, CD34+ cells were isolated from bone marrows of healthy donors (HD), MDS and AML patients and were treated with iHCK or vehicle (DMSO) in liquid culture, for three days. Meanwhile, HS-5 mesenchymal cells were cultured into the 3D bioscaffold. iHCK or vehicle treated CD34+ cells were introduced into the 3D bioscaffold containing HS-5 and evaluated after 7 and 14 days, by light microscopy (hematoxilin and eosin regular staining) and immunohistochemistry (expression of CD34 and CD90 antigens). NOD.CB17-Prkdcscid/J mice received 2 Gy irradiation followed by transplantation with caudal intravenous injection of leukemia cells obtained from hCG-PML-RARα transgenic mice. After acute promyelocytic leukemia (APL) establishment, animals were treated or not with intraperitoneally iHCK and peripheral blood was collected for hematological analysis and protein was extracted from spleen and bone marrows for Western Blot analysis. ANOVA and Student's T-Test were used. Results.In leukemia cell lines and primary cells, the combinatory treatment of iHCK and Cytarabine (1μM) or 5-Azacitidine (1μM) demonstrated synergistic effects, compared to either drug alone, on the reduction of growth and induction of cell death (P<0.001; Figure 1). Further, Western blot revealed increased BAX expression and decreased BCL-XL expression. Moreover, iHCK treatment was able to reduce the activation of oncogenic pathways, MAPK/ERK and PI3K/AKT, leading to severe reduction of ERK, AKT and p70S6 phosphorylation. Treatment with iHCK reduced CD34+ MDS and AML cells proliferation cultured into the 3D bioscaffold but had no effect upon normal CD34+cells. In vivo analysis showed that APL mice treated with iHCK (5μM) for 48h had reduced leukocyte number compared to APL mice treated with vehicle (13.2±1.1 vs 49.4±18.8; P<0.001). No alterations in hemoglobin levels and platelet were found. Likewise, the in vivo iHCK (2.5μM, 5.0μM or 10.0μM) treatment decreased the phosphorylation of ERK, AKT and P70S6K proteins of leukemic cells (Figure 2). Conclusion.The iHCK pharmacological inhibitor has an antiproliferative activity in leukemic cells without altering cell death and survival rate of normal cells, demonstrating on-target malignant cell killing activity as a single agent or in combination with Azacytidine (Aza) or Cytarabine (Ara-C). Disclosures No relevant conflicts of interest to declare.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.