Search Results (124)

Acute Lymphoblastic Leukemia (ALL) is a heterogeneous hematological malignancy in which disease progression and response to therapy are influenced by a complex network of molecular alterations, interactions with the bone marrow microenvironment, and epigenetic modulation mechanisms. Crosstalk between oncogenic, inflammatory, and immunoregulatory signaling pathways, together with epigenetic modifications, contributes to the maintenance of leukemic survival and the development of therapeutic resistance. This review analyzes the role of cytokines and chemokines such as IL-6, TNF-α, and CXCL12, which act as biological biomarkers and key mediators of leukemia niche remodeling, and the main signaling pathways involved in ALL, such as Wnt/β-catenin, JAK/STAT, PI3K/AKT/mTOR, Notch, and BCR, highlighting their functional interconnection with the tumor microenvironment. The role of epigenetics in modulating the dialogue between leukemia cells and stromal components is also discussed. Epigenetic programs govern leukemia’s dependence on stromal support, inflammatory and niche-derived signals, as well as the microenvironment signaling pathways. Overall, targeting leukemia-niche interactions is a crucial strategy for improving outcomes in ALL and to identify potential molecular vulnerabilities, also for developing new therapeutic approaches for the treatment of the disease. Full article

Background: Donor lymphocyte infusion (DLI) is commonly used to prevent or treat leukemic relapse following allogeneic hematopoietic cell transplantation; however, efficacy is limited by immune exhaustion, checkpoint-mediated inhibition, and the risk of graft-versus-host disease (GvHD). Gamma delta (γδ) T-cells represent a promising “off-the-shelf” adoptive cell therapy (ACT) with favorable safety and MHC-independent cytotoxicity, yet their function is similarly constrained by the leukemic tumor microenvironment (TME). Acute exercise mobilizes cytotoxic lymphocyte subsets, and is an emerging strategy to enhance cellular immunotherapies, including DLI and expanded γδ T-cells. This study examined how exercise-mobilized lymphocytes and exercise-expanded γδ T-cells interact with TIGIT blockade to improve anti-leukemic activity. Methods: Healthy participants completed an acute cycling bout, after which peripheral blood mononuclear cells (PBMCs) and ex vivo expanded γδ T-cells were phenotyped and cytotoxicity was determined against leukemia cells with TIGIT checkpoint inhibition. The therapeutic relevance of combining TIGIT blockade with rest- or exercise-expanded γδ T-cells was further evaluated in NSG-IL15 mice challenged with K562-luc leukemia. Results: Acute exercise increased circulating CD8⁺ and γδ T-cells with higher TIGIT and PD-1 expression. Exercise-expanded γδ T-cells maintained increased PD-1 and TIGIT expression and exhibited increased co-expression of DNAM-1 and TIGIT. Exercise mobilized PBMCs and exercise-expanded γδ T-cells demonstrated enhanced cytotoxicity, further amplified by TIGIT blockade. In vivo, TIGIT-treated exercise-expanded γδ T-cells modestly improved tumor suppression and prolonged tumor-free survival compared to untreated controls. Conclusions: Exercise primes DLI and γδ T-cell products for enhanced responsiveness to TIGIT checkpoint inhibition. Targeting TIGIT likely augments DNAM-1 dependent cytotoxicity and improves anti-leukemic activity, supporting the integration of exercise-enhanced DLI and γδ T-cell therapies with immune checkpoint blockade as a safe strategy to improve relapse control in leukemia. Full article

Background: Acute lymphoblastic leukemia (ALL) is a hematological malignancy characterised by uncontrolled proliferation of lymphoid cells. Despite improved outcomes with modern chemotherapy, treatment resistance and adverse effects remain major clinical challenges. Curcumin, a natural compound from Curcuma longa, has shown anticancer potential in multiple malignancies, including leukemia. This systematic review aims to summarise preclinical and clinical evidence on the anti-leukemic effects and mechanisms of action of curcumin in ALL. Methods: A literature search was conducted in August 2025 across PubMed, Scopus, Ovid MEDLINE, and Web of Science according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. Primary research involving in vitro, in vivo, and human studies examining curcumin’s anti-leukemic effects on ALL were included. Of the 2034 records screened, 26 articles met the inclusion and exclusion criteria. Results: Curcumin inhibited proliferation and induced cytotoxicity and apoptosis in ALL cells via reactive oxygen species generation, DNA damage, mitochondrial dysfunction, and caspase activation. It also inhibited the Janus kinase/signal transducer and activator of transcription (JAK/STAT) and phosphoinositol-3 kinase/protein kinase B (PI3K/AKT) signalling, downregulated breakpoint cluster region-Abelson (BCR-ABL), Wilms tumor 1 (WT1), and Multidrug resistance 1 (MDR1) mRNAs, and induced ceramide accumulation and autophagy. In vivo evidence was limited, and no human studies were identified. Conclusions: Curcumin exerts multi-targeted anti-leukemic effects in ALL. Clinical translation is constrained by its poor bioavailability and limited clinical data. Future research should focus on improving the bioavailability of curcumin via chemical or pharmaceutical modification, as well as conducting well-designed clinical trials. Full article

Background/Objectives: Imatinib, the first tyrosine kinase inhibitor, marks the beginning of a revolution in clinical oncology. Disrupting oncogenic kinase-dependent signaling pathways represents a key strategy for advancing targeted cancer therapies. Terpene analogues of imatinib were developed to probe the influence of terminal ring modifications on BCR-ABL inhibition and downstream oncogenic signaling. Methods: Nine novel imatinib analogues bearing bulky aliphatic moieties were designed, synthesised, and structurally characterized by ¹H/¹³C NMR spectroscopy and high-resolution mass spectrometry (HRMS). Molecular docking calculations were performed to assess the binding modes and intermolecular interactions. The cytotoxicity of the newly synthesized imatinib derivatives was evaluated across a panel of BCR-ABL+ leukemia cell lines. Results: Molecular docking analyses demonstrated conserved interactions within the ATP-binding site of BCR-ABL for all derivatives, with calculated docking scores ranging between 123 and 128, while modifications at the terminal ring introduced subtle changes in electrostatic and steric profiles. Biological evaluation using MTT-based cytotoxicity assays in BCR-ABL+ leukemic cell lines revealed enhanced antiproliferative activity compared with imatinib, with compounds 6a (flexible cyclohexyl) and 6d (rigid camphane-type (+)-isopinocampheyl) exhibiting the lowest micromolar activity in the AR-230 model (IC₅₀ values of 1.1 and 1.2 μM, respectively). Proteome-wide phosphokinase profiling demonstrated shared suppression of STAT5/3/6, RSK1/2, S6K1/p70, and Pyk2, confirming effective disruption of canonical BCR-ABL pathways. Critically, the terpene moiety dictated downstream pathway bias: 6a preferentially attenuated CREB activation, whereas 6d more effectively suppressed the PI3K/Akt oncogenic axis and strongly activated proapoptotic p53-mediated stress responses. Conclusions: Our findings establish terpene-engineered imatinib analogues as tunable modulators and promising candidates for targeting downstream BCR-ABL signaling pathways in leukemia treatment. Full article

This manuscript presents the development of an electrochemical biosensor designed to detect K-562 chronic myeloid leukemia (CML) cells. The biosensor was made of highly oriented pyrolytic graphite (HOPG), functionalized with -OH and -COOH groups by surface etching with strong acids, and subsequently coated with modified titanium dioxide (TiO₂-m). TiO₂-m is TiO₂ modified during its synthesis process using carbon nanotubes functionalized with -OH and -COOH groups. These changes improve the electron transfer kinetics and physicochemical properties of the electrode surface. TiO₂-m improves the sensitivity and selectivity towards leukemic cells. The detection process involved three stages: cell culture, cell adhesion onto the TiO₂–m electrode, and measurement of the electrochemical signal. Fluorescence microscopy and SEM-EDS confirmed cell adhesion and pseudopod formation on the TiO₂-m surface, which is an important finding because K-562 cells are typically nonadherent. Cyclic voltammetry (VC) and differential pulse voltammetry (VDP) demonstrated rapid and sensitive detection of leukemic cells within the concentration range of 6250 to 1,000,000 cells/mL, achieving high reproducibility and strong linearity (R² = 98%) with a detection time of 25 s. The VC and VDP demonstrated rapid and sensitive detection of leukemic cells over a concentration range of 6250 to 1,000,000 cells/mL, achieving adequate reproducibility and stable linearity (R² = 98%), with a detection time of 25 s. These results indicate that the TiO₂-m biosensor is a promising platform for the rapid and efficient electrochemical detection of leukemia cells. Full article

Background/Objectives: In the current medical era, Topoisomerase II is recognized as an essential enzyme that regulates DNA topology during critical biological processes such as DNA replication, transcription, and repair. This study aimed to design, synthesize, and biologically evaluate a new series of pyrazolo[3,4-b]pyridines (8a–g, 10a–g, and 12) as potential anticancer agents and Topoisomerase II inhibitors. Methods: The synthesized compounds were subjected to in vitro anticancer screening at the National Cancer Institute (NCI, USA). Active derivatives were further evaluated through a five-dose screening to determine their antiproliferative potency. Selected compounds were examined for their effects on leukemia cell lines (K562 and MV4-11), and mechanistic studies were performed to assess DNA damage, cell cycle distribution, and apoptosis-related protein modulation. Additionally, enzyme inhibition assays were conducted to determine Topoisomerase IIα (TOPIIα) inhibition. Results: Initial single-dose screening identified several active compounds, notably 8b, 8c, 8e, 8f, 10b, 10c, 10e, and 10f. Among these, compound 8c exhibited potent and broad-spectrum antiproliferative activity across the NCI cancer cell line panel, with a GI₅₀ MG-MID value of 1.33 µM (range: 0.54–2.08 µM). The synthesized molecules showed moderate to good anti-leukemic efficacy against K562 and MV4-11 cells. Mechanistic investigations revealed that compound 8c induced DNA damage and S-phase cell cycle arrest, leading to apoptosis as evidenced by the modulation of PARP-1, Bax, XIAP, and Caspases. Furthermore, target-based assays confirmed that compound 8c significantly inhibited the DNA relaxation activity of TOPIIα in a dose-dependent manner, comparable to etoposide. Conclusions: The study highlights compound 8c as a promising pyrazolo[3,4-b]pyridine derivative with potent antiproliferative activity and effective inhibition of Topoisomerase IIα. These findings suggest its potential as a lead scaffold for further optimization in anticancer drug development.. Full article

Despite advances with novel targeted agents (e.g., BCL-2 or IDH inhibitors) combined with chemotherapy for acute myeloid leukemia (AML), drug resistance persists. We investigated whether blocking Na⁺/H⁺ exchanger 1 (NHE1) could enhance AML cell sensitivity to the BCL-2 inhibitor venetoclax and sought to determine the molecular mechanisms. Our results demonstrated that co-treatment with venetoclax and the NHE1 inhibitor 5-(N,N-hexamethylene) amiloride (HMA) synergistically induced apoptosis in both venetoclax-sensitive and -resistant leukemic cell lines. Specifically, the combination significantly increased apoptosis in venetoclax-resistant THP-1 cells to 72.28% (17.79% with 100 nM venetoclax and 10.15% with 10 μM HMA alone; p < 0.001). Conversely, another venetoclax-resistant line, U-937, showed no significant apoptotic response to the combination. In THP-1 cells, this synergy was mediated via a caspase-dependent programmed cell death pathway, evidenced by an increased BAX/BCL-2 ratio, mitochondrial cytochrome c release, and subsequent caspase-9 and caspase-3 activation. Furthermore, co-treatment downregulated the anti-apoptotic protein MCL-1 and reduced PI3K and Akt phosphorylation, suggesting that inhibition of these survival pathways also contributed to the synergistic effect. Inhibition of NHE1 may substantially enhance venetoclax sensitivity in certain AML models, particularly in venetoclax-resistant THP-1 cells but not in U-937, highlighting biological diversity and the probable involvement of alternative survival pathways. Full article

The BCR-ABL fusion oncoprotein, a constitutively active tyrosine kinase, plays a central role in the pathogenesis of chronic myeloid leukemia (CML). While tyrosine kinase inhibitors (TKIs) have transformed CML treatment, issues such as drug resistance, particularly involving mutations like T315I, and adverse effects underscore the need for alternative or complementary therapeutic strategies. Natural products derived from plants have long served as a reservoir for anticancer agents, offering structural diversity and multi-targeted bioactivity. Notably, many plant-based compounds exhibit anticancer effects with comparatively lower toxicity and fewer side effects than synthetic TKIs, making them attractive candidates for safer long-term use. This review explores the recent advances in plant-based natural compounds that directly or indirectly inhibit BCR-ABL kinase activity and its downstream signaling pathways. Key compounds are discussed with respect to their mechanisms of action, structure–activity relationships, and potential to overcome TKI resistance. Several of these compounds directly target BCR-ABL or promote its degradation, while others inhibit downstream effectors such as STAT5 and PI3K/Akt, leading to apoptosis and growth inhibition of leukemic cells. The synergistic potential of these natural products with existing TKIs and their promise to target drug-resistant CML cells further highlight their translational value. By integrating insights from molecular pharmacology, medicinal chemistry, and leukemia biology, this review supports the continued investigation of plant-derived agents as novel or adjunctive therapies against BCR-ABL-driven leukemias. Full article

Background/Objectives: Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm characterized by the BCR–ABL fusion gene, whose constitutive tyrosine kinase activity drives leukemogenesis. Although tyrosine kinase inhibitors (TKIs) have revolutionized treatment, drug resistance and leukemic stem cell persistence remain major challenges. Natural compounds such as polyphenols have shown potential in modulating key oncogenic pathways in CML. Results: Polyphenols such as resveratrol, quercetin, curcumin, and epigallocatechin gallate (EGCG) demonstrated significant antiproliferative and pro-apoptotic effects in CML cell lines, including imatinib-resistant models. These effects were mediated through the modulation of signaling pathways, including PI3K/Akt, STAT5, and MAPK; inhibition of BCR–ABL expression; induction of oxidative stress; and the enhancement of apoptosis via mitochondrial and caspase-dependent mechanisms. Some polyphenols also showed synergistic activity with TKIs, potentiating their efficacy and overcoming resistance. Conclusions: Preclinical evidence supports the role of polyphenols as potential adjuvants in CML therapy, particularly in drug-resistant contexts. Their pleiotropic molecular actions and low toxicity profile make them promising candidates for integrative oncology. Nonetheless, clinical translation requires further investigation through well-designed trials assessing efficacy, safety, and pharmacokinetics. Full article

The aim of this paper is to obtain ethyl (2-(methylcarbamoyl)phenyl)carbamate and its metal complexes as promising antimicrobial agents. The title compound was synthesized using the ring-opening of isatoic anhydride with methylamine and further acylation with ethyl chloroformate. All metal complexes were successfully obtained after mixing the ligand dissolved in DMSO and water solutions of the corresponding metal salts and sodium hydroxide, in a metal-to-ligand-to base ratio 1:2:2. As a result, mixed ligand complexes of ethyl 2-(methylcarbamoyl)phenyl)carbamate and 3-methylquinazoline-2,4(1H,3H)-dione were obtained. The obtained complexes were characterized by their melting points, FTIR, NMR spectroscopy, and MP-AES. Then, the antimicrobial effect of the compounds against both Gram-negative and Gram-positive bacteria, yeasts, and fungi was studied. Only the Co(II) complex showed antimicrobial activity against almost all Gram-positive and Gram-negative bacteria. The cobalt complex exhibited promising antimicrobial activity against Gram-positive Micrococcus luteus with inhibition zones of 20 mm, Listeria monocytogenes (15 mm), Staphylococcus aureus (13 mm), as well as Gram-negative Klebsiella pneumoniae (13 mm) and Proteus vulgaris (13 mm). Given the potential of metal complexes as antimicrobial agents, understanding their cytotoxic effects is crucial for evaluating their therapeutic safety. To assess the in vitro biocompatibility of the experimental compounds, a range of cell viability assays was conducted using human malignant leukemic cell lines (LAMA-84, K-562) and normal murine fibroblast cells (CCL-1). The Ni(II) complex shows IC₅₀ = 105.1 µM against human malignant leukemic cell lines LAMA-84. Based on the reported results, it may be concluded that the mixed cobalt complex of 2-(methylcarbamoyl)phenyl)carbamate and 3-methylquinazoline-2,4(1H,3H)-dione can be attributed as a promising antimicrobial agent. Future in vivo tests will contribute to establishing the antimicrobial properties of this complex. Full article

Despite the successes achieved in recent years in the treatment of childhood acute lymphoblastic leukemia (ALL), high-risk ALL in particular still represents a considerable challenge, with poorer outcomes. The PI3K/AKT/mTOR signaling pathway is frequently constitutively activated in ALL and consequently leads to unrestricted cell proliferation, without showing frequent mutations in the most important representatives of the signaling pathway. Recent studies have shown that fine balanced protein expression is a common way to adjust oncogenic B cell directed receptor signaling and to mediate malignant cell proliferation and survival in leukemic cells. Too low expression of inhibitory phosphatases can lead to constitutive signaling of kinases, which are important for cell proliferation and survival. In contrast, marked high expression levels of key phosphatases enable cells with distinct pronounced oncogenic B cell directed receptor signaling to escape negative selection by attenuating signal strength and thus raising the threshold for deletion checkpoint activation. One of the most important B cell receptor-dependent signaling cascades is the PI3K/AKT signaling pathway, with its important antagonist SHIP1. However, recent data show that the inositol-5-phosphatase SHIP1 is differentially expressed across the heterogeneity of the ALL subtypes, making the overall therapeutic strategy targeting SHIP1 more complex. The aim of this article is therefore to provide an overview of the current knowledge about SHIP1, its expression in the various subtypes of ALL, its regulation, and the molecules that influence its gene and protein expression, to better understand its role in the pathogenesis of leukemia and other human cancers. Full article

L-asparaginase (L-ASNase) remains a vital chemotherapeutic agent for acute lymphoblastic leukemia (ALL), primarily due to its mechanism of depleting circulating asparagine essential for leukemic cell proliferation. However, existing ASNases (including pegylated ones) face limitations including immunogenicity, rapid clearance, and off-target toxicities. Earlier, we have shown that the conjugation of L-ASNase with the polyamines and their copolymers results in significant enhancement of the antiproliferative activity due to accumulation in tumor cells. We suggested that this effect is probably mediated by polyamine transport system (PTS) receptors that are overexpressed in ALL cells. Here, we investigated the effect of competitive inhibitors of PTS receptors to the L-ASNase interaction with cancer cells (L5178Y, K562 and A549). L-ASNase from Rhodospirillum rubrum (RrA), Erwinia carotovora (EwA), and Escherichia coli (EcA) were conjugated with natural polyamines (spermine—spm, spermidine—spd, putrescine—put) and a synthetic branched polymer, polyethyleneimine 2 kDa (PEI2 ), using carbodiimide chemistry. Polyamine conjugation with L-ASNase significantly increased enzyme binding and cellular uptake, as quantified by fluorimetry and confocal microscopy. This increased cellular uptake translated into increased cytotoxicity of L-ASNase conjugates. The presence of competitive ligands to PTS receptors decreased the uptake of polyamine-conjugated enzymes-fatty acid derivatives of polyamines produced the strongest suppression. Simultaneously with this suppression, in some cases, competitive ligands to PTS significantly promoted the uptake of the native unconjugated enzymes, “equalizing” the cellular access for native vs conjugated ASNase. The screening for competing inhibitors of PTS receptor-mediated endocytosis revealed spermine and caproate/lipoate derivatives as the most potent inhibitors or antagonists, significantly reducing the cytostatic efficacy of polyamine-conjugated ASNases. The results obtained emphasize the complex, cell-type-dependent and inhibitor-specific nature of these interactions, which highlights the profound involvement of PTS in L-ASNase internalization and cytotoxic activity. These findings support the viability of polyamine conjugation as a strategy to enhance L-ASNase delivery and therapeutic efficacy by targeting the PTS. Full article

Background and Objectives: Philadelphia (Ph)-negative myeloproliferative neoplasms can exhibit defects in Janus kinase 2 (JAK2), Calreticulin (CalR), and MPL genes. It is possible that the presence of other driver mutations may influence diagnosis and prognosis in patients who do not have a JAK2 gene mutation. The purpose of this study was to assess the frequency of CalR and MPL gene mutations and the clinical effects of these mutations in JAK2 gene-unmutated MPN patients from a single center. Materials and Methods: We examined 46 patients (ET/PMF: 34/12) diagnosed with MPNs regarding their genetic conditions, diagnoses, and complications. Results: CalR Type 1 gene mutation was detected in 26.1% of cases, CalR Type 2 gene mutation in 13.0%, MPL-L gene mutation in 2.2%, and MPL-K gene mutation in 6.5%. In total, 56.5% of patients were triple-negative. The presence of CalR Type 1 and Type 2 mutations was significantly more prevalent in patients with essential thrombocytosis (ET), although the difference did not reach statistical significance (p = 0.51, p = 0.57). In contrast, MPL mutations were only observed in patients with primary myelofibrosis (PMF). Conclusions: We found no correlation between thrombosis, leukemic transformation, and driver mutations. MPL gene mutation was present in only myelofibrosis patients, and CALR gene mutation was present in one of the three cases of leukemic transformation. The triple-negative group had a lower survival rate, but this difference was not statistically significant (110.3 months vs. 121.4 months, respectively, p = 0.53). However, the sample size was quite small. Our limited observations suggest a possible trend that requires confirmation. Full article

Although 60% of AML patients respond well to standard chemotherapy, most patients eventually relapse, develop chemoresistance, and do not survive more than five years. Targeted therapies, including analogs of imiquimod belonging to the family of imiqualines, emerged as promising agents against AML. Notably, the first-generation imiqualine EAPB0503 proved selective potency against nucleophosmin-1-mutant (NPM1c) AML. Recently, chemical modifications of EAPB0503 led to the development of the lead compound from the second generation, EAPB02303. Here, we demonstrate that EAPB02303 displays 200-fold greater potency, broader activity across AML subtypes, and, importantly, a distinct mechanistic profile when compared to EAPB0503. Unlike EAPB0503, which primarily targeted NPM1c AML cells, EAPB02303 exhibits broad-spectrum activity across various AML subtypes. Remarkably, EAPB02303 anti-leukemic activity was attributed to the inhibition of PI3K/AKT/mTOR signaling activity. Nevertheless, NPM1c AML cells were more sensitive to EAPB02303, likely due to its ability to promote NPM1c protein degradation. In vivo, EAPB02303 potently reduced the leukemic burden and improved organ tumor infiltration in both wt-NPM1 and NPM1c AML xenograft mice. Yet, the significant prolonged survival was exclusive to NPM1c AML xenografts, likely due to superior response conferred by NPM1c degradation. Overall, these findings highlight the potential of EAPB02303 as a powerful therapeutic agent for a range of AML subtypes, supporting its further development for broader clinical use. Full article

The underlying structural features of the mismatch between catalytic and cytostatic properties in L-asparaginase from Rhodospirillum rubrum (RrA) and three of its mutants were investigated. The rationale for selecting the specific mutations (RrA_{A64V, E67K}; RrA_{R118H, G120R}; RrA_{E149R, V150P, F151T}) is to elucidate the role of inter-subunit interaction in RrA and its impact on catalytic efficiency and stability. Bioinformatic modeling revealed a predominantly negative surface charge on RrA with limited positive charge clusters in the vicinity of the interface region. Thus, some negatively charged groups were replaced with positively charged ones to enhance the electrostatic interactions and stabilize the enzyme quaternary structure. RrA_{A64V, E67K} and RrA_{R118H, G120R} additionally contained an N-terminal 17-amino acid capsid peptide derived from the bacteriophage T7 (MASMTGGQQMGRGSSRQ), which could potentially affect the conformational stability of theenzymes. Circular dichroism (CD) spectroscopy was applied to the kinetic parameters analysis of Asn hydrolysis and showed that native RrA displayed a V_max of 30 U/mg and a K_M of 4.5 ± 0.5 mM. RrA_{E149R, V150P, and F151T} exhibited a substantially increased V_max of 57 U/mg. The catalytic efficiency of V_max/K_M also improved compared to the native enzyme: the V_max/K_M increased from approximately 7 U/mg × mM⁻¹ (for the native enzyme) to 9 U/mg × mM⁻¹ for Mut3. Other mutants exhibited less pronounced changes. Thermo-denaturation studies allowed us to determine the phase transition parameters of the RrA variants in comparison with commercial reference sample EcA. RrA_{A64V, E67K} and RrA_{R118H, G120R} exhibited the most favorable phase transition parameters, with melting temperatures (T_m) of 60.3 °C and 59.4 °C, respectively, exceeding that of the wild-type RrA (54.6 °C) and RrA_{E149R, V150P, F151T} (52 °C). The EcA demonstrated a slightly superior thermal stability, with a T_m of 62 °C. The mutations showed a significant effect on protein stability during trypsinolysis. Therefore, RrA_{E149R, V150P, F151T} showed higher resistance (45% activity remaining after 30 min of trypsin exposure) compared to the native RrA retained 20% activity. EcA preparations exhibited lower stability to trypsinolysis (losing over 90% activity in 15 min). The cytostatic effects were evaluated using MTT assays against K562 (leukemic) and A549 (lung carcinoma) cell lines. The MTT assays with K562 cells revealed that RrA_{E149R, V150P, F151T} (IC₅₀ of 10 U/mL) and RrA_{R118H, G120R} (IC₅₀ of 11.5 U/mL) exhibited superior antiproliferative activity compared to native enzymes RrA (IC₅₀ of 15 U/mL) and EcA (24 U/mL). RrA_{E149R, V150P, F151T} showed the most significant improvement in cytostatic activity. The results obtained indicate that the substitutions in RrA_{E149R, V150P, F151T} resulted in the improvement of the enzyme biocatalytic properties and an increase in the resistance to aggregation and trypsinolysis. This highlights the role of electrostatic interactions in stabilizing the oligomeric structure of the enzyme, which eventually translates into an improvement in cytostatic efficiency and antiproliferative forces. Full article