Differential Expression of LMNA/C and Insulin Receptor Transcript Variants in Peripheral Blood Mononuclear Cells of Leukemia Patients

Background: Recent research has identified alternative transcript variants of LMNA/C (LMNA, LMNC, LMNAΔ10, and LMNAΔ50) and insulin receptors (INSRs) as potential biomarkers for various types of cancer. The objective of this study was to assess the expression of LMNA/C and INSR transcript variants in peripheral blood mononuclear cells (PBMCs) of leukemia patients to investigate their potential as diagnostic biomarkers. Methods: Quantitative TaqMan reverse transcriptase polymerase chain reaction (RT-qPCR) was utilized to quantify the mRNA levels of LMNA/C (LMNA, LMNC, LMNAΔ10, and LMNAΔ50) as well as INSR (IR-A and IR-B) variants in PBMCs obtained from healthy individuals (n = 32) and patients diagnosed with primary leukemias (acute myeloid leukemia (AML): n = 17; acute lymphoblastic leukemia (ALL): n = 8; chronic myeloid leukemia (CML): n = 5; and chronic lymphocytic leukemia (CLL): n = 15). Results: Only LMNA and LMNC transcripts were notably present in PBMCs. Both exhibited significantly decreased expression levels in leukemia patients compared to the healthy control group. Particularly, the LMNC:LMNA ratio was notably higher in AML patients. Interestingly, IR-B expression was not detectable in any of the PBMC samples, precluding the calculation of the IR-A:IR-B ratio as a diagnostic marker. Despite reduced expression across all types of leukemia, IR-A levels remained detectable, indicating its potential involvement in disease progression. Conclusions: This study highlights the distinct expression patterns of LMNA/C and INSR transcript variants in PBMCs of leukemia patients. The LMNC:LMNA ratio shows promise as a potential diagnostic indicator for AML, while further research is necessary to understand the role of IR-A in leukemia pathogenesis and its potential as a therapeutic target.

Hsa_circ_0012152 and Hsa_circ_0001857 Accurately Discriminate Acute Lymphoblastic Leukemia From Acute Myeloid Leukemia

Acute leukemia (AL) is a group of highly heterogeneous hematological malignancies. Circular RNAs (circRNAs) are covalently closed circRNA molecules implicated in the development of many diseases. However, the role of circRNAs in AL remains largely unknown. Therefore, this study aimed to identify new classification diagnostic biomarkers for subgroups of AL. The circRNA expression signatures discriminating acute lymphoblastic leukemia (ALL) from acute myeloid leukemia (AML) were identified by microarray, followed by reverse transcription quantitative polymerase chain reaction (RT-qPCR) validation. Receiver operating characteristic curve analysis was used to evaluate the diagnostic efficiencies of hsa_circ_0001857 and hsa_circ_0012152, and hsa_circ_0012152 was selected for Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis. The results showed that the circRNA expression profiles, hsa_circ_0001857, and hsa_circ_0012152 could clearly discriminate ALL from AML. The target genes of hsa_circ_0012152 might be involved in biological processes, such as myeloid cell differentiation, covalent chromatin modification, histone modification, and rat sarcoma (Ras) protein signal transduction, and participate in pathways such as mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3′-kinase (PI3K)-Akt signaling pathway. Hsa_circ_0012152 might be involved in the initiation and development of AML through miR-491-5p/epidermal growth factor receptor (EGFR)/MAPK1 or miR-512-3p/EGFR/MAPK1 axis. Our results showed that circRNA expression profiles and specifically expressed circRNAs were promising classification biomarkers to designate AL into ALL or AML.

Spectral-spatial feature-based neural network method for acute lymphoblastic leukemia cell identification via microscopic hyperspectral imaging technology

Microscopic examination is one of the most common methods for acute lymphoblastic leukemia (ALL) diagnosis. Most traditional methods of automized blood cell identification are based on RGB color or gray images captured by light microscopes. This paper presents an identification method combining both spectral and spatial features to identify lymphoblasts from lymphocytes in hyperspectral images. Normalization and encoding method is applied for spectral feature extraction and the support vector machine-recursive feature elimination (SVM-RFE) algorithm is presented for spatial feature determination. A marker-based learning vector quantization (MLVQ) neural network is proposed to perform identification with the integrated features. Experimental results show that this algorithm yields identification accuracy, sensitivity, and specificity of 92.9%, 93.3%, and 92.5%, respectively. Hyperspectral microscopic blood imaging combined with neural network identification technique has the potential to provide a feasible tool for ALL pre-diagnosis.

Canine acute leukaemia: 50 cases (1989-2014)

Acute leukaemia (AL) is a bone marrow malignancy of hematopoietic progenitors that historically is poorly responsive to treatment. With the widespread adoption of dose-intense chemotherapy, more human patients attain long-term survivals, but whether comparable progress has been made in canine AL is unknown. To investigate this question, medical records from three academic veterinary hospitals were reviewed. Fifty dogs met the criteria for AL, having excess circulating or marrow blasts, a major cytopenia(s), and no substantial lymphadenopathy. Thirty-six dogs received cytotoxic chemotherapy; 23 achieved a complete or partial response for a median of 56 days (range, 9-218). With failure or relapse, 14 dogs were rescued. Median survival with treatment was poor at 55 days (range, 1-300). Untreated (n = 6) and palliatively-treated (n = 8) dogs lived a median of 7.5 days. Most dogs developed chemoresistance within weeks of initiating treatment, and consequently, survival times for AL remain disappointingly short.

Acute Myeloid Leukemia: Clinical Spectrum of 125 Patients

BACKGROUND

Acute myeloid leukemia is an acquired clonal heterogeneous stem cell disorder. Hence, various parameters are sought out to categorize this disease into subtypes, so that as a consequence specific treatment modalities can be offered. Conventionally, the practically used method for classification utilizes French American British (FAB) criteria based on morphology and cytochemistry. The aim of present study was to determine the current spectrum of AML sub types in patients in Karachi.

MATERIALS AND METHODS

This single centre cross sectional study was conducted at Liaquat National Hospital, Karachi, extending from January 2010 to December 2014. Data were retrieved from archives were analyzed with SPSS version 22.

RESULTS

A total of 125 patients were diagnosed at our institution with de novo AML during five years period, 76 males and 49 females. Median age was 34.5 years. AML-M1 was the predominant FAB subtype (23.2%) followed by M2 (18.4%), M3 and M4 (16% each), M0 (14.4%), M5 (7.2%), M6 (3.2%) and M7 (1.6%).

CONCLUSIONS

AML in Pakistani patients is seen in a relatively young population. The most common FAB subtype observed in our study was acute myeloblastic leukemia, without maturation (M1).

Myeloid neoplasias: what molecular analyses are telling us

In the last decades, cytogenetic and molecular characterizations of hematological disorders at diagnosis and followup have been most valuable for guiding therapeutic decisions and prognosis. Genetic and epigenetic alterations detected by different procedures have been associated to different cancer types and are considered important indicators for disease classification, differential diagnosis, prognosis, response, and individualization of therapy. The search for new biomarkers has been revolutionized by high-throughput technologies. At this point, it seems that we have overcome technological barriers, but we are still far from sorting the biological puzzle. Evidence based on translational research is required for validating novel genetic and epigenetic markers for routine clinical practice. We herein discuss the importance of genetic abnormalities and their molecular pathways in acute myeloid leukemia, myelodysplastic syndromes, and myeloproliferative neoplasms. We also discuss how novel genomic abnormalities may interact and reassess concepts and classifications of myeloid neoplasias.

Different susceptibilities to 1,25-dihydroxyvitamin D3-induced differentiation of AML cells carrying various mutations

This study was designed to compare the differentiation-inducing potential of 1,25-dihydroxyvitamin D(3) (1,25D) with some analogs (VDAs) in a panel of acute myeloid leukemia (AML) cell lines and in blast cells isolated from patients with AML. Of the cell lines studied, HL60 proved to be the most sensitive to each of the differentiation-inducing agents when compared to THP-1, NB-4 and U-937 cell lines. Three of the VDAs tested (PRI-1906, PRI-2191 and PRI-2201) were similarly effective as 1,25D in all the cell lines tested. However, blast cells from AML showed a varying sensitivity towards 1,25D. For example, blast cells isolated from patients in which the whole or part of chromosome 7 was deleted were extremely sensitive to 1,25D and its analogs. In contrast, 1,25D failed to increase the expression of differentiation markers in blast cells isolated from patients carrying activating mutations in Flt3 gene. Since, the expression of vitamin D receptor (VDR) in cells with Flt3 mutations was increased to the same extent as in other AML cells this suggests that failure of these cells to differentiate lies downstream of the receptor. That blast cells with different cytogenetic abnormalities have dissimilar responses to 1,25D and its analogs, may have implications in the use of 1,25D as a 'differentiation therapy' for myeloid leukemias. The analog PRI-2191 (tacalcitol) was found to be the most potent in inducing patient's cells differentiation.

Genomic profiling of myeloid sarcoma by array comparative genomic hybridization

Myeloid sarcoma (MS) is a tumor mass of myeloblasts or immature myeloid cells occurring in an extramedullary site. In this study, seven cases of MS [stomach (1), testis (1), skin (2), and lymph node (3)] and 3 synchronous and 1 follow-up bone marrow (BM) samples were studied for genomic abnormalities using array comparative genomic hybridization (array-CGH). Array-CGH construction used approximately 5,400 bacterial artificial chromosome clones from the RPCI-11 library, spanning the human genome. Data were analyzed using the DNAcopy software and custom heuristics. All MS cases had genomic abnormalities detected by array-CGH. Unbalanced genomic abnormalities in five MS cases were confirmed by conventional cytogenetics (CC) and/or fluorescence in situ hybridization (FISH); these abnormalities included loss of 4q32.1-q35.2, 6q16.1-q21, and 12p12.2-p13.2 and gain of 8q21.2-q24.3, 8, 11q21-q25, 13q21.32-q34, 19, and 21. Array-CGH was also invaluable in identifying possible deletions, partner translocations, and breakpoints that were questionable by CC. The remaining two MS cases had genomic aberrations detected by array-CGH, but were not studied further by CC/FISH. Chromosome 8 was most commonly abnormal (3/7 cases). Identical genomic abnormalities were demonstrated in MS and in synchronous BM in two cases. These results demonstrate that array-CGH is a powerful tool to screen MS tissue for unbalanced genomic abnormalities, allowing identification of chromosome abnormalities when concurrent BM is nonanalyzable or nonleukemic.

A systematic literature review of the clinical and epidemiological burden of acute lymphoblastic leukaemia (ALL)

Our goal was to identify and summarize the published literature pertaining to the incidence, prevalence, mortality, aetiology, clinical diagnosis, and management of acute lymphoblastic leukaemia (ALL). Acute lymphoblastic leukaemia represents 12% of all leukaemia cases, with a worldwide incidence projected to be 1-4.75 per 100,000 people. Italy, the United States (US), Switzerland, and Costa Rica are the countries with the highest incidence of ALL. Hereditary link, genetic defects, and possibly radiation or chemical exposures are listed amongst the most significant risk factors. Acute lymphoblastic leukaemia is predominantly a disease of childhood, but it affects adults as well. It accounts for 80% of all leukaemia cases in children. The incidence is slightly higher in men than in women and greater in white people than in black people. In 2003 in the US, there were an estimated 5800 deaths from ALL. Presenting signs and symptoms of ALL are fairly non-specific and include fever, anaemia, petechiae, and bone and joint pain. Staging of the disease and patient risk profile are routinely performed to define ALL subtypes and guide management. Chemotherapy, cranial radiation in patients with high-risk disease, and stem cell transplantation for selected patients are the prevalent therapies. Complete remission rates are high, especially amongst children (even 100%); however, long-term survival at 10 years (event-free survival) is in the range of 63% for children and 25-35% for adults. This implies that there is still a strong need for new therapies to maintain remission and prolong survival. Future treatment strategies may be driven by the patient's minimal residual disease status, a measure that more precisely defines remission, prognosis, responsiveness to therapy, and expected long-term survival.

The current clinical value of genomic instability

Clinical Oncologists have largely ignored the debate over genetic instability in human cancers. It is clear that genetic lesions themselves provide valuable information in the treatment of patients with cancer and those genetic lesions can be exploited successfully as therapeutic targets. Whether the mechanisms resulting in the accumulation of genetic lesions can be translated and used clinically remains to be seen.

Microgranular and t(11;17)/PLZF-RARalpha variants of acute promyelocytic leukemia also present the flow cytometric pattern of CD13, CD34, and CD15 expression characteristic of PML-RARalpha gene rearrangement

Acute promyelocytic leukemia (APL) is a subtype acute myeloid leukemia in which leukemic promyelocytes predominate in the bone marrow (BM). Rapid diagnosis is critical for treatment decision since all-trans-retinoic acid must be administrated promptly. The microgranular variant may be of difficult diagnosis, as it may be confused with other diseases on morphological grounds. The purpose of this study was to determine if the microgranular variant has the same antigenic profile as the classical hypergranular type. The immunophenotype of leukemic cells from the bone marrow of 50 patients, with the PML-RARalpha gene rearrangement confirmed by RT-PCR, was determined by flow cytometry using a large panel of 22 monoclonal antibodies and a polyclonal anti-TdT antibody. Thirty-four cases were classified as classical APL and 16 as microgranular APL. The immunophenotypic profile of the two subtypes was indistinguishable concerning the presence or absence of these antigens, including the absence of reactivity for the HLA-DR antigen. The simultaneous immunophenotypic combination of a unique major cell population, heterogeneous intensity of expression of CD13, and the typical pattern of CD15/CD34 expression were similarly present in the hypergranular and microgranular subtypes. Homogeneous expression of CD33 was observed in 76% of the classical APL cases and in 100% of the microgranular cases. Additionally, we have studied two cases of PLZF-RARalpha APL that also displayed the same immunophenotype described for classical APL. Thus, the immunophenotypic profile highly characteristic of the PML-RARalpha gene rearrangement was also observed in microgranular and PLZF-RARalpha variants of APL.

Myelodysplasia and the acute myeloid leukaemias

The myelodysplastic syndromes are increasingly recognised clinical entities reflecting a stem cell defect that gives rise to ineffective clonal haematopoiesis. The spectrum extends from relatively indolent refractory anaemia through varying combinations of leucopoenia and thrombocytopenia to acute leukaemia. Diagnosis rests on marrow hypercellularity with dysplastic morphology, apoptosis and, often distinctive cytogenetic defects. Stratification to risk-related protocols range from occasional blood transfusions or erythropoietin through innovative options including thalidomide or amifostine to haematopoietic stem cell transplantation in selected individuals. Acute myeloid leukaemia, conceptually segregated from preleukaemia, is treated differently although accumulating cellular and molecular data favour a more integrated approach. Morphology and immunophenotyping are complemented by molecular genetics. On this basis chemotherapy alone is sufficient in defined sub-groups whereas others benefit by autologous or allogeneic grafting. Attention to demonstrating minimal residual disease is the basis for more specific intervention exemplified by monoclonal antibodies or maturation-inducing agents as with retinoic acid in acute progranulocytic leukaemia

Increased IkappaB kinase activity is associated with activated NF-kappaB in acute myeloid blasts

NF-kappaB/Rel transcription factors are modulators of immune and inflammatory processes and are also involved in malignancy. Phosphorylation of the IkappaB inhibitors by the IkappaB kinase (IKK) complex leads to their proteasomal degradation, resulting in activated NF-kappaB. Here, we investigated the activation status of NF-kappaB and the IKK complex in acute myeloid leukemia (AML). Gelshift assays revealed an increased level of activated nuclear NF-kappaB in myeloid blasts. Both bone marrow and peripheral blood blasts from AML patients showed enhanced IKK activity relative to controls, whereas the IKK protein concentrations were comparable. In addition, an increased level of IkappaB-alpha was detected in AML blast cells, although this appeared to be insufficient to block nuclear translocation of NF-kappaB, also confirmed by immunofluorescence. In subtype M4 and M5 AML cells a more extensive NF-kappaB activation and higher IKK activity was found than in M1/M2 specimens. Isolated AML blasts cultured ex vivo responded to external stimulation (TNF, LPS) by further IKK activation, IkappaB degradation and NF-kappaB activation. Preincubation with the proteasome inhibitor PSI inhibited the NF-kappaB system in isolated AML blasts. This study established for the first time a dysregulation of IKK signaling in AML leading to increased NF-kappaB activity suggesting potential therapeutic avenues.

Acute leukemia

This article provides a review of the acute leukemias with updated basic and practical information. The main emphasis is on techniques used to arrive at the correct diagnosis. Although morphology and cytochemistry were the mainstays of diagnosis in the past, new developments in immunophenotyping, cytogenetics, molecular biology, and in vitro assays have improved the understanding of this disease dramatically and enable the identification of new entities with distinct clinicobiologic features.

The vascular endothelial growth factor (VEGF) signaling pathway: a therapeutic target in patients with hematologic malignancies

Angiogenesis is an important component in the progression and metastasis of solid tumors. We now appreciate that angiogenesis is also critically involved in the pathogenesis of hematologic malignancies. Current data suggest important prognostic and therapeutic implications of angiogenesis in a variety of malignancies of the hematopoietic system, including acute and chronic leukemias, myeloproliferative diseases, multiple myeloma, non-Hodgkin's lymphomas, and Hodgkin's disease. Vascular endothelial growth factor (VEGF) is a major angiogenic factor that regulates multiple endothelial cell functions, including mitogenesis. Cellular and circulating levels of VEGF are elevated in hematologic malignancies and are adversely associated with prognosis. Angiogenesis is a very complex, tightly regulated, multistep process, the targeting of which may well prove useful in the creation of novel therapeutic agents. Current approaches being investigated include the inhibition of angiogenesis stimulants (e.g., VEGF), or their receptors, blockade of endothelial cell activation, inhibition of matrix metalloproteinases, and inhibition of tumor vasculature. Preclinical, phase I, and phase II studies of both monoclonal antibodies to VEGF and blockers of the VEGF receptor tyrosine kinase pathway indicate that these agents are safe and offer potential clinical utility in patients with hematologic malignancies.

Targeting hypomethylation of DNA to achieve cellular differentiation in myelodysplastic syndromes (MDS)

Considerable progress has been made recently in defining and understanding the diverse members of the group of hematologic disorders now known as the myelodysplastic syndrome (MDS). New systems of classification, based on the latest cytogenetic methodologies, have generated better prognostic data, and basic research has more closely associated molecular mechanisms with clinical subgroups. The mechanisms underlying most cases of myelodysplasia appear to be an array of chromosomal abnormalities leading to suppression of normal myeloid cell differentiation and dominance of abnormal, immature cells. The process is progressive and is mediated by a variety of cytokines, potential loss of tumor suppressor genes, aberrations in signal transduction pathways, and perhaps immune mechanisms. Hypermethylation of specific DNA sequences has been implicated in the pathogenesis of MDS. Until recently, treatment options have been few, high risk, and mostly ineffective. New discoveries, particularly in the area of stimulating remaining normal myeloid cells to resume growth and differentiation, hold promise for safer treatment regimens and improved outcomes. Among the promising new agents are nucleoside analogues, such as 5-azacytidine and decitabine, which reactivate tumor suppressor gene transcription through effects on DNA methylation.