Chronic myeloid leukemia as a stem cell-derived malignancy

Chronic myeloid leukemia (CML) is a myeloproliferative disease of the hematopoietic stem cells, characterized by the presence of the Philadelphia (Ph) chromosome. Although imatinib inhibits the BCR-ABL kinase activity, clinical experiences confirm that imatinib may not target CML stem cells in vivo. The identification of signaling pathways responsible for the self-renewal properties of leukemic stem cells in CML will help in the discovery of novel therapeutic targets. Here we review signaling pathways including Wnt/β-catenin, Hedgehog, Alox5, and Foxo which play crucial roles in the maintenance of stem cell functions in CML. It is thought that inhibition of key genes that are part of self-renewal associated signaling pathways may provide an effective way to reduce aberrant stem cell renewal in CML

Toward a noncytotoxic glioblastoma therapy: blocking MCP-1 with the MTZ Regimen

To improve the prognosis of glioblastoma, we developed an adjuvant treatment directed to a neglected aspect of glioblastoma growth, the contribution of nonmalignant monocyte lineage cells (MLCs) (monocyte, macrophage, microglia, dendritic cells) that infiltrated a main tumor mass. These nonmalignant cells contribute to glioblastoma growth and tumor homeostasis. MLCs comprise of approximately 10%-30% of glioblastoma by volume. After integration into the tumor mass, these become polarized toward an M2 immunosuppressive, pro-angiogenic phenotype that promotes continued tumor growth. Glioblastoma cells initiate and promote this process by synthesizing 13 kDa MCP-1 that attracts circulating monocytes to the tumor. Infiltrating monocytes, after polarizing toward an M2 phenotype, synthesize more MCP-1, forming an amplification loop. Three noncytotoxic drugs, an antibiotic - minocycline, an antihypertensive drug - telmisartan, and a bisphosphonate - zoledronic acid, have ancillary attributes of MCP-1 synthesis inhibition and could be re-purposed, singly or in combination, to inhibit or reverse MLC-mediated immunosuppression, angiogenesis, and other growth-enhancing aspects. Minocycline, telmisartan, and zoledronic acid - the MTZ Regimen - have low-toxicity profiles and could be added to standard radiotherapy and temozolomide. Re-purposing older drugs has advantages of established safety and low drug cost. Four core observations support this approach: 1) malignant glioblastoma cells require a reciprocal trophic relationship with nonmalignant macrophages or microglia to thrive;2) glioblastoma cells secrete MCP-1 to start the cycle, attracting MLCs, which subsequently also secrete MCP-1 perpetuating the recruitment cycle;3) increasing cytokine levels in the tumor environment generate further immunosuppression and tumor growth;and 4) MTZ regimen may impede MCP-1-driven processes, thereby interfering with glioblastoma growth

Implications of Complement Imbalance in COVID-19: A Molecular Mechanistic Discussion on the Importance of Complement Balance

Two central questions in COVID-19 treatment which should be considered are: “How does the imbalance of the complement system affect the therapeutic approaches?” and “Do we consider complement inhibitors in therapeutic protocols?”. The complement system is a double-edged sword since it may either promote immune responses against COVID-19 or contribute to destructive inflammation in the host. Therefore, it is crucial to regulate this system with complement inhibitors. In this manuscript, we discuss the molecular mechanisms of complement and complement inhibitors in COVID-19 patients. We searched the terms “COVID-19”, “Complement”, “Complement inhibitor”, “SARS-CoV-2”, and all complement fragments and inhibitors from 2000 to 2022 in PubMed and google scholar and checked the pathways in “KEGG pathway database”. Complement is not well-appreciated in the treatment protocols despite its multiple roles in the disease, and most of the preventive anti-inflammatory therapeutic approaches did not include a complement inhibitor in COVID-19 therapeutic protocols. In this review article, we discussed the most recent studies regarding complement components mediated interventions and the mechanism of these interventions in COVID-19 patients. Since the control of the complement system overactivation is associated with a better prognosis in the initial stages of COVID-19, heparin, anti-thrombin, C1-inhibitor, montelukast, and hydralazine can be effective in the initial stages of this viral infection. Recombinant complement activation (RCA) proteins are more effective in regulating complement compared to terminal pathway therapeutic approaches such as the C3a and C5a inhibitors

Thrombocytopenia in leukemia: Pathogenesis and prognosis

Leukemias, a heterogeneous group of hematological disorders, are characterized by ineffective hematopoiesis and morphologic abnormalities of hematopoietic cells. Thrombocytopenia is a common problem among leukemia types that can lead to hemorrhagic complications in patients. The purpose of this review article is to identify the conditions associated with the incidence of thrombocytopenia in leukemias. It can be stated that although translocations have been considered responsible for this complication in many studies, other factors such as bone marrow failure, genes polymorphism, a mutation in some transcription factors, and the adverse effects of treatment could be associated with pathogenesis and poor prognosis of thrombocytopenia in leukemias. Considering the importance of thrombocytopenia in leukemias, it is hoped that the recognition of risk factors increasing the incidence of this complication in leukemic patients would be useful for prevention and treatment of this disorder

The expression of CD markers in solid tumors: Significance in metastasis and prognostic value

Objective. The clusters of differentiations (CDs) are among the surface markers expressed on different cells in the body, which are involved in the communication of cells with each other and the induction of signaling. Moreover, the evaluation of the ectopic expression of these markers in solid tumors has led to the detection of disease in early stages. In this paper, we have examined the effect of CD markers expression on the function of cancer cells, as well as their importance as the diagnostic and prognostic factors for monitoring the progression of solid tumors. Materials and methods Relevant literature was identified by a PubMed search (1988-2017) of English the language papers using the terms “CD markers”, “diagnostic”, “prognostic”, “predictive marker” and “solid tumors.” Discussion. Finally, it can be stated that the evaluation of CDs is not only of diagnostic value at disease onset, but these markers can be used as prognostic and predictive markers to contribute to the treatment of disease and predict its relapse. Conclusion. Monitoring of tumors progression through CDs expressed on circulating tumor cells could be a new diagnostic and prognostic factor in the future

Neoplastic Bone Marrow Niche: Hematopoietic and Mesenchymal Stem Cells

The neoplastic niche comprises complex interactions between multiple cell typesand molecules requiring cell-cell signaling as well as local secretion. These nichesare important for both the maintenance of cancer stem cells and the inductionof neoplastic cells survival and proliferation. Each niche contains a population oftumor stem cells supported by a closely associated vascular bed comprising mesenchyme-derived cells and extracellular matrix. Targeting cancer stem cells andneoplastic niche may provide new therapies to eradicate tumors. Much progresshas been very recently made in the understanding of the cellular and molecularinteractions in the microenvironment of neoplastic niches. This review articleprovides an overview of the neoplastic niches in the bone marrow. In addition tohighlighting recent advances in the field, we will also discuss components of theniche and their signaling pathways

The impact of Mir-9 regulation in normal and malignant hematopoiesis

MicroRNA-9 (MiR-9) dysregulation has been observed in various cancers. Recently, MiR-9 is considered to have a part in hematopoiesis and hematologic malignancies. However, its importance in blood neoplasms is not yet well defined. Thus, this study was conducted in order to assess the significance of MiR-9 role in the development of hematologic neoplasia, prognosis, and treatment approaches. We have shown that a large number of MiR-9 targets (such as FOXOs, SIRT1, CCND1, ID2, CCNG1, Ets, and NFkB) play essential roles in leukemogenesis and that it is overexpressed in different leukemias. Our findings indicated MiR-9 downregulation in a majority of leukemias. However, its overexpression was reported in patients with dysregulated MiR-9 controlling factors (such as MLLr). Additionally, prognostic value of MiR-9 has been reported in some types of leukemia. This study generally emphasizes on the critical role of MiR-9 in hematologic malignancies as a prognostic factor and a therapeutic target