L-asparaginase mediated therapy in L-asparagine auxotrophic cancers: A review

Microbial L-asparaginase is the most effective first-line therapeutic used in the treatment protocols of paediatric and adult leukemia. Leukemic cell’s auxotrophy for L-asparagine is exploited as a therapeutic strategy to mediate cell death through metabolic blockade of L-asparagine using L-asparaginase. Escherichia coli and Erwinia chrysanthemi serve as the major enzyme deriving sources accepted in clinical practise and the enzyme has bestowed improvements in patient outcomes over the last 40 years. However, an array of side effects generated by the native enzymes due to glutamine co-catalysis and short serum stays augmenting frequent dosages, intended a therapeutic switch towards the development of biobetter alternatives for the enzyme including the formulations resulting in sustained local depletion of L-asparagine. In addition, the treatment with L-asparaginase in few cancer types has proven to elicit drug-induced cytoprotective autophagy mechanisms and therefore warrants concern. Although the off-target glutamine hydrolysis has been viewed in contributing the drug-induced secondary responses in cells deficient with asparagine synthetase machinery, the beneficial role of glutaminase-asparaginase in proliferative regulation of asparagine prototrophic cells has been looked forward. The current review provides an overview on the enzyme’s clinical applications in leukemia and possible therapeutic implications in other solid tumours, recent advancements in drug formulations, and discusses the aspects of two-sided roles of glutaminase-asparaginases and drug-induced cytoprotective autophagy mechanisms.

Spontaneous apoptosis and BCL2 gene expression as predictors of early death and short overall survival in acute leukemia patients: a prospective, case cohort study

Background Spontaneous apoptosis and expression of MCL1, BCL2, and BCL-XL may be useful prognostic markers in acute leukemia patients. The purpose of this study is to examine the prognosis in adult leukemia patients based on spontaneous apoptosis and anti-apoptosis gene expressions in circulating leukocytes. Results Early, late, and total apoptosis were significantly increased in peripheral blood leukocytes from patients diagnosed with acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) compared to controls and in cases of ALL versus AML (P < 0.001). Total apoptosis decreased significantly in AML and ALL patients who died early (ED); P = 0.001 and P = 0.002, respectively. Anti-apoptosis genes MCL1, BCL2, and BCL-XL were upregulated in 62.4%, 64.2%, and 62.4% of the acute leukemia patients, respectively. Among the AML patients, the up-regulation of BCL2 was paradoxically associated with increased apoptosis and low rates of ED. The expression levels of MCL1 and BCL-XL had no significant prognostic values; among patients diagnosed with non-acute promyelocytic leukemia (non-APL-AML), total spontaneous apoptosis, expression of BCL2, and performance status were independent predictors of overall survival (OS). Conclusion Total spontaneous apoptosis and BCL2 gene expression may be valuable independent markers for OS in patients with non-APL-AML. Moreover, in ALL patients decreased levels of spontaneous apoptosis were associated with ED, although this was not a significant predictor of OS.

Evaluation of MLPA as a comprehensive molecular cytogenetic tool to detect cytogenetic markers of chronic lymphocytic leukemia in Egyptian patients

Background Chronic lymphocytic leukemia (CLL) is the most common form of adult leukemia. This disease is genetically heterogeneous, and approximately 85% of patients with CLL harbor chromosomal aberrations that are considered effective prognostic biomarkers. The most frequent aberrations include deletions in 13q14, followed by trisomy 12, and deletions in 11q22.3 and 17p13 (TP53). Currently, fluorescence in situ hybridization (FISH) is the most widely used molecular cytogenetic technique to detect these aberrations. However, FISH is laborious, time-consuming, expensive, and has a low throughput. In contrast, multiplex ligation-dependent probe amplification (MLPA) is a reliable, cost-effective, and relatively rapid technique that can be used as a first-line screening tool and complement with FISH analysis. This study aimed to evaluate the contributions of MLPA as a routine standalone screening platform for recurrent chromosomal aberrations in CLL in comparison to other procedures. Thirty patients with CLL were screened for the most common genomic aberrations using MLPA with SALSA MLPA probemix P038-B1 CLL and FISH. Results In 24 of the 30 cases (80%), the MLPA and FISH results were concordant. Discordant results were attributed to a low percentage of mosaicism. Moreover, the MLPA probemix contains probes that target other genomic areas known to be linked to CLL in addition to those targeting common recurrent CLL aberrations. Conclusions The usage of MLPA as the first screening platform followed by FISH technique for only the negative cases is the most appropriate approach for CLL diagnosis and prognosis.

Identification of Clinically Relevant Subgroups of Chronic Lymphocytic Leukemia Through Discovery of Abnormal Molecular Pathways

Chronic lymphocytic leukemia (CLL) is the most common form of adult leukemia in the Western world with a highly variable clinical course. Its striking genetic heterogeneity is not yet fully understood. Although the CLL genetic landscape has been well-described, patient stratification based on mutation profiles remains elusive mainly due to the heterogeneity of data. Here we attempted to decrease the heterogeneity of somatic mutation data by mapping mutated genes in the respective biological processes. From the sequencing data gathered by the International Cancer Genome Consortium for 506 CLL patients, we generated pathway mutation scores, applied ensemble clustering on them, and extracted abnormal molecular pathways with a machine learning approach. We identified four clusters differing in pathway mutational profiles and time to first treatment. Interestingly, common CLL drivers such as ATM or TP53 were associated with particular subtypes, while others like NOTCH1 or SF3B1 were not. This study provides an important step in understanding mutational patterns in CLL.

αvβ3 Integrin Expression and Mitogenic Effects by Thyroid Hormones in Chronic Lymphocytic Leukemia

Background: Chronic lymphocytic leukemia (CLL) is the most common adult leukemia. The thyroid hormones, T3 and T4, bind the αvβ3 integrin and activate phosphorylates ERK (pERK). These tumor-promoting actions were reported in a number of malignancies, but not in CLL. Methods: Primary cells from 22 CLL patients were verified for disease markers (CD5/CD19/CD23) and analyzed for αvβ3 by flow cytometry (FC), ImageStream, Western blots (WB), and immunohistochemistry (IHC) in archival bone marrow (BM, n = 6) and lymph node (LN, n = 5) tissues. Selected samples (n = 8) were incubated with T3 (1–100 nM) or T4 (0.1–10 µM) for 30 min, and the expression levels of αvβ3, pERK and PCNA (cell proliferation marker) were determined (WB). Results: αvβ3 was detected on the membrane of circulating CLL cells and in the BM but not in the LN. T3 and T4 enhanced αvβ3 protein levels in primary CLL cells. Similarly, pERK and PCNA were rapidly induced in response to T3 and T4 exposure. Conclusions: αvβ3 integrin is expressed on primary CLL cells and is induced by thyroid hormones. We further suggest that the hormones are mitogenic in these cells, presumably via αvβ3-mediated signaling.

Nurse-Like Cells and Chronic Lymphocytic Leukemia B Cells: A Mutualistic Crosstalk inside Tissue Microenvironments

Chronic lymphocytic leukemia (CLL) is the most common adult leukemia in Western countries and is an example of hematological disease where cooperation between genetic defects and tumor microenvironmental interaction is involved in pathogenesis. CLL is a disease that is considered as “addicted to the host”; indeed, the crosstalk between leukemic cells and the tumor microenvironment is essential for leukemic clone maintenance supporting CLL cells’ survival, proliferation, and protection from drug-induced apoptosis. CLL cells are not innocent bystanders but actively model and manipulate the surrounding microenvironment to their own advantage. Besides the different players involved in this crosstalk, nurse-like cells (NLC) resemble features related to leukemia-associated macrophages with an important function in preserving CLL cell survival and supporting an immunosuppressive microenvironment. This review provides a comprehensive overview of the role played by NLC in creating a nurturing and permissive milieu for CLL cells, illustrating the therapeutic possibilities in order to specifically target and re-educate them.

Survival Rate of Patients with Acute Leukemia: A Case Study in Iran

Background: Acute leukemia is a kind of aggressive disease that includes high rates of fatalities in the world, in particular in Iran. This research was done to determine the survival rate of patients with acute leukemia in Iran. Methods: 85 adult patients who were first diagnosed with acute leukemia in Shahid Bahonar hospital of Kerman during March 2012 until March 2013 were evaluated in a retrospective descriptive study to measure the death/life status in a 5-year period (2012-2017). The required data was gathered from medical records of patients, HIS system data, and the cancer registry system, and the Kaplan-Meier estimator and Log Rank test were used to calculate the survival rate using SPSS23. Results: Survival rate was completely 45.9 % for patients with acute adult leukemia. It was 47.08 % in acute myelogenous leukemia (AML) and it was 43.06 % in acute lymphocytic leukemia (ALL). The 1,2,3,4 and 5-year survival of acute leukemia was respectively 87.1 %, 69.4 %, 62.4 %, 56.5 % and 45.9 %. Conclusion: Iran's health system should design and plan to increase the survival of patients with acute leukemia by improving the methods and facilities to diagnose and treat it more quickly and more effectively.

Chronic Myeloid Leukemia (CML) in Adolescents & Young Adults (AYA): Single Institution 10 Years Experience with 1st Line Imatinib Mesylate (IM)

Introduction and Aims: CML is the commonest adult leukemia in India and the disease is diagnosed commonly in the 3rd or 4th decade of life - at least 10 years earlier than in the west, making the disease an important issue in AYA cancers. The present study reports our 10 year experience (all patients registered after 2005 with minimum of 3 years follow up) with the use of 1st line IM in patients of CML Chronic Phase (CML-CP) in patients aged 15 to 29 years. Methods: Patients of CML-CP receiving 1st line IM, aged 15 to 29 were included in the study. Standard demographics; hematological response, molecular responses (RQ-PCR on International Scale) q 6 monthly and toxicity of IM were assessed. Results A total of 337 patients of CML-CP were registered, 89 (28.7%) of which were aged between 15 to 29 and were on 1st line IM. These are reported in this study. Age distribution: 15 to 19 years: 17 (19.1%); 20 to 24: 26 (29.2%); 24 to 29: 46 (51.7%). Male female ratio: 53 (59.5%) to 36 (40.5%). Sixty one (68.5%) received innovator IM (Glivec) through the GIPAP (Glivec International Patient Assistance Program), 28 (40.5%) generic IM. At 10 years f/u, 6 (6.7%) patients were lost to f/u, 15 (16.8%) off imatinib (12 sub-optimal molecular response/relapse, and 3 b/o toxicity - 2 hepatitis, 1 renal). Seventy four (74) patients continue on IM, 56 on 400 mg/day and 18 on &gt; 400mg/day. Fifty nine are in deep molecular response, 15 have a bcr/abl between 0.1 to 1.0 but are in complete hematological remission. Musculo-skeletal toxicity, grade I to II: 11/74 (14.8%), skin toxicity grade I: 27/74 (36.5%) and GI grade I to II: 16/74 (21.6%) were seen. Discussion and Conclusion CML is a common cancer in AYA in developing countries. IM, including generic IM, remains the standard 1st line drug for the majority and is effective, well tolerated in most patients. Issues related to treatment-free-remission (TFR), compliance, long-term drug toxicity and fertility need to be studied in this young population. Disclosures No relevant conflicts of interest to declare.