The Role of WRAP53 in Cell Homeostasis and Carcinogenesis Onset.

The WD repeat containing antisense to TP53 (WRAP53) gene codifies an antisense transcript for tumor protein p53 (TP53), stabilization (WRAP53α), and a functional protein (WRAP53ß, WDR79, or TCAB1). The WRAP53ß protein functions as a scaffolding protein that is important for telomerase localization, telomere assembly, Cajal body integrity, and DNA double-strand break repair. WRAP53ß is one of many proteins known for containing WD40 domains, which are responsible for mediating a variety of cell interactions. Currently, WRAP53 overexpression is considered a biomarker for a diverse subset of cancer types, and in this study, we describe what is known about WRAP53ß's multiple interactions in cell protein trafficking, Cajal body formation, and DNA double-strand break repair and its current perspectives as a biomarker for cancer.

Development and Clinical Applications of PI3K/AKT/mTOR Pathway Inhibitors as a Therapeutic Option for Leukemias.

Leukemias are hematological neoplasms characterized by dysregulations in several cellular signaling pathways, prominently including the PI3K/AKT/mTOR pathway. Since this pathway is associated with several important cellular mechanisms, such as proliferation, metabolism, survival, and cell death, its hyperactivation significantly contributes to the development of leukemias. In addition, it is a crucial prognostic factor, often correlated with therapeutic resistance. Changes in the PI3K/AKT/mTOR pathway are identified in more than 50% of cases of acute leukemia, especially in myeloid lineages. Furthermore, these changes are highly frequent in cases of chronic lymphocytic leukemia, especially those with a B cell phenotype, due to the correlation between the hyperactivation of B cell receptors and the abnormal activation of PI3Kδ. Thus, the search for new therapies that inhibit the activity of the PI3K/AKT/mTOR pathway has become the objective of several clinical studies that aim to replace conventional oncological treatments that have high rates of toxicities and low specificity with target-specific therapies offering improved patient quality of life. In this review we describe the PI3K/AKT/mTOR signal transduction pathway and its implications in leukemogenesis. Furthermore, we provide an overview of clinical trials that employed PI3K/AKT/mTOR inhibitors either as monotherapy or in combination with other cytotoxic agents for treating patients with various types of leukemias. The varying degrees of treatment efficacy are also reported.

Molecular and Clinical Insights in the Increasing Detection of BCR::ABL1 p190+ in Adult Acute Myeloid Leukemia Patients.

BACKGROUND/AIM: Acute myeloid leukemia (AML) is a myeloproliferative neoplasm marked by abnormal clonal expansion of hematopoietic progenitor cells, displaying karyotypic aberrations and genetic mutations as prognostic indicators. The World Health Organization (WHO) and the European LeukemiaNet guidelines categorize BCR::ABL1 p190+ AML as high risk. This study explored the identification of the increased incidence of BCR::ABL1 p190+ in our AML population. PATIENTS AND METHODS: This study included 96 AML patients stratified according to WHO guidelines. Subsequently, patients were screened for genetic abnormalities, such as BCR::ABL1 p 190+, PML::RARA, RUNX1::RUNX1T1, and CBFB::MYH11 by quantitative reverse transcription polymerase chain reaction (RT-qPCR) analysis. RESULTS: Among 96 AML patients, 36 displayed BCR::ABL1 p190+, overcoming the expected global incidence. Age variations (19 to 78 years) showed no significant laboratory differences between BCR::ABL1 p190+ and non-BCR::ABL p190+ cases. The overall survival analysis revealed no statistically significant differences among the patients (p=0.786). CONCLUSION: The analyzed population presented a higher frequency of BCR::ABL1 p190+ detection in adult AML patients when compared to what is described in the worldwide literature. Therefore, more studies are needed to establish the reason why this incidence is higher and what the best treatment approach should be in these cases.

Association of CD38+ Immunophenotyping Biomarker With a Better Prognosis in Elderly Acute Myeloid Leukemia Patients.

BACKGROUND/AIM: The relevance of cytogenetic markers as prognostic risk factors has been demonstrated in a vast number of studies, with many prognostication tools utilizing these factors to determine treatment approaches. Patients aged above 60 years represent an important subgroup of acute myeloid leukemia (AML) patients, especially because they usually exhibit a poorer cytogenetic landscape and are less suitable for intensive treatments. The importance of evaluating prognostic parameters in AML, especially in low-income countries, prompted an investigation into CD38 expression and its effects. PATIENTS AND METHODS: Medical records of AML patients aged above 60 years from three hospitals in Brazil's northwest region were analyzed. A total of 67 patients were evaluated in terms of overall survival and factors predicting worse outcomes. The risk stratification was performed based on the European LeukemiaNet 2022 guidelines. The analysis of immunophenotyping markers was conducted using multi-parametric flow cytometry. RESULTS: The overall survival of CD38-positive AML patients was higher than that of patients with CD38-negative AML, with survival rates of 15.6 months versus 4 months, respectively (p-value=0.026). The impact of CD38 positivity was relevant also in multivariable Cox proportional hazards regression, demonstrating a positive effect on overall survival, with a hazard ratio of 0.33 (95%CI=0.13-0.79; p-value=0.014). CONCLUSION: Expression of CD38 in patients with AML was associated with better overall survival and serves as a relevant predictor of improved outcome in patients aged above 60 years.

Association between Immunophenotypic Parameters and Molecular Alterations in Acute Myeloid Leukemia.

Acute myeloid leukemia (AML) is a hematologic malignancy that occurs due to alterations such as genetic mutations, chromosomal translocations, or changes in molecular levels. These alterations can accumulate in stem cells and hematopoietic progenitors, leading to the development of AML, which has a prevalence of 80% of acute leukemias in the adult population. Recurrent cytogenetic abnormalities, in addition to mediating leukemogenesis onset, participate in its evolution and can be used as established diagnostic and prognostic markers. Most of these mutations confer resistance to the traditionally used treatments and, therefore, the aberrant protein products are also considered therapeutic targets. The surface antigens of a cell are characterized through immunophenotyping, which has the ability to identify and differentiate the degrees of maturation and the lineage of the target cell, whether benign or malignant. With this, we seek to establish a relationship according to the molecular aberrations and immunophenotypic alterations that cells with AML present.

Leukemic Stem Cell: A Mini-Review on Clinical Perspectives.

Hematopoietic stem cells (HSCs) are known for their ability to proliferate and self-renew, thus being responsible for sustaining the hematopoietic system and residing in the bone marrow (BM). Leukemic stem cells (LSCs) are recognized by their stemness features such as drug resistance, self-renewal, and undifferentiated state. LSCs are also present in BM, being found in only 0.1%, approximately. This makes their identification and even their differentiation difficult since, despite the mutations, they are cells that still have many similarities with HSCs. Although the common characteristics, LSCs are heterogeneous cells and have different phenotypic characteristics, genetic mutations, and metabolic alterations. This whole set of alterations enables the cell to initiate the process of carcinogenesis, in addition to conferring drug resistance and providing relapses. The study of LSCs has been evolving and its application can help patients, where through its count as a biomarker, it can indicate a prognostic factor and reveal treatment results. The selection of a target to LSC therapy is fundamental. Ideally, the target chosen should be highly expressed by LSCs, highly selective, absence of expression on other cells, in particular HSC, and preferentially expressed by high numbers of patients. In view of the large number of similarities between LSCs and HSCs, it is not surprising that current treatment approaches are limited. In this mini review we seek to describe the immunophenotypic characteristics and mechanisms of resistance presented by LSCs, also approaching possible alternatives for the treatment of patients.

Kinase Inhibition in Multiple Myeloma: Current Scenario and Clinical Perspectives.

Multiple myeloma (MM) is a blood cell neoplasm characterized by excessive production of malignant monoclonal plasma cells (activated B lymphocytes) by the bone marrow, which end up synthesizing antibodies or antibody fragments, called M proteins, in excess. The accumulation of this production, both cells themselves and of the immunoglobulins, causes a series of problems for the patient, of a systemic and local nature, such as blood hyperviscosity, renal failure, anemia, bone lesions, and infections due to compromised immunity. MM is the third most common hematological neoplasm, constituting 1% of all cancer cases, and is a disease that is difficult to treat, still being considered an incurable disease. The treatments currently available cannot cure the patient, but only extend their lifespan, and the main and most effective alternative is autologous hematopoietic stem cell transplantation, but not every patient is eligible, often due to age and pre-existing comorbidities. In this context, the search for new therapies that can bring better results to patients is of utmost importance. Protein tyrosine kinases (PTKs) are involved in several biological processes, such as cell growth regulation and proliferation, thus, mutations that affect their functionality can have a great impact on crucial molecular pathways in the cells, leading to tumorigenesis. In the past couple of decades, the use of small-molecule inhibitors, which include tyrosine kinase inhibitors (TKIs), has been a hallmark in the treatment of hematological malignancies, and MM patients may also benefit from TKI-based treatment strategies. In this review, we seek to understand the applicability of TKIs used in MM clinical trials in the last 10 years.