Search Results (541)

Current treatments against leukemia present several limitations, prompting the search for new therapeutic agents, particularly those derived from natural products. In this context, structural modifications were performed on the triterpene 3α,24-dihydroxylup-20(29)-en-28-oic acid (T1), isolated from Phoradendron wattii. Among the five derivatives obtained, 3α,24-dihydroxy-30-oxolup-20(29)-en-28-oic acid (T1c) exhibited the highest activity, with an IC₅₀ value of 12.90 ± 0.1 µM against THP-1 cells. T1c significantly reduced cell viability in both acute lymphoblastic leukemia (CCRF-CEM, REH, JURKAT, and MOLT-4) and acute myeloid leukemia (THP-1) cell lines, inducing apoptosis after 48 h of treatment, while showing minimal cytotoxicity toward normal mononuclear cells (MNCs). In silico molecular docking studies were conducted against three key protein targets: BCL-2 (B-cell lymphoma 2), EGFR (epidermal growth factor receptor, tyrosine kinase domain), and FLT3 (FMS-like tyrosine kinase 3). The lowest binding energies (kcal/mol) observed were as follows: T1–BCL-2: −10.12, EGFR: −12.75, FLT3: −14.05; T1c–BCL-2: −10.23, EGFR: −14.50, FLT3: −14.07; T2–BCL-2: −11.59, EGFR: −15.00, FLT3: −14.03. These findings highlight T1c as a promising candidate in the search for anti-leukemic drugs which deserves further study. Full article

Background: Lysosomal-associated membrane protein 1 (LAMP1), typically localized to the lysosomal membrane, is increasingly implicated as a marker of cancer aggressiveness and metastasis when expressed on the cell surface. This study aimed to develop a LAMP1-targeted antibody-based PET tracer and assess its efficacy in mouse models of human breast and colon adenocarcinoma. Methods: To determine the source of LAMP1 expression, we utilized human single-cell RNA sequencing and spatial transcriptomics, complemented by in-house flow cytometry on xenografted mouse models. Tissue microarrays of multiple epithelial cancers and normal tissue were stained for LAMP-1, and staining was quantified. An anti-LAMP1 monoclonal antibody was conjugated with desferrioxamine (DFO) and labeled with zirconium-89 (⁸⁹Zr). Human triple-negative breast cancer (MDA-MB-231) and colon cancer (Caco-2) cell lines were implanted in nude mice. PET/CT imaging was conducted at 24, 72, and 168 h post-intravenous injection of ⁸⁹Zr-DFO-anti-LAMP1 and ⁸⁹Zr-DFO-IgG (negative control), followed by organ-specific biodistribution analyses at the final imaging time point. Results: Integrated single-cell and spatial RNA sequencing demonstrated that LAMP1 expression was localized to myeloid-derived suppressor cells (MDSCs) and cancer-associated fibroblasts (CAFs) in addition to the cancer cells. Tissue microarray showed significantly higher staining for LAMP-1 in tumor tissue compared to normal tissue (3986 ± 2635 vs. 1299 ± 1291, p < 0.001). Additionally, xenograft models showed a significantly higher contribution of cancer cells than the immune cells to cell surface LAMP1 expression. In vivo, PET imaging with ⁸⁹Zr-DFO-anti-LAMP1 PET/CT revealed detectable tumor uptake as early as 24 h post-injection. The ⁸⁹Zr-DFO-anti-LAMP1 tracer demonstrated significantly higher uptake than the control ⁸⁹Zr-DFO-IgG in both models across all time points (MDA-MB-231 SUV_max at 168 h: 12.9 ± 5.7 vs. 4.4 ± 2.4, p = 0.003; Caco-2 SUV_max at 168 h: 8.53 ± 3.03 vs. 3.38 ± 1.25, p < 0.01). Conclusions: Imaging of cell surface LAMP-1 in breast and colon adenocarcinoma is feasible by immuno-PET. LAMP-1 imaging can be expanded to adenocarcinomas of other origins, such as prostate and pancreas. Full article

Ferrocene (Fc), a redox-active organometallic scaffold, has attracted significant attention in medicinal chemistry due to its favorable physicochemical and pharmacological properties. The present study explores the therapeutic potential of novel Fc-functionalized analogues of imatinib and nilotinib, aimed at targeting BCR-ABL1+ chronic myeloid leukemia (CML) cells. A series of Fc-based derivatives (compounds 6, 9, 14, and 18) were synthesized by systematically substituting key pharmacophoric regions of the parent tyrosine kinase inhibitors with Fc units. The antiproliferative activity of these compounds was evaluated against four BCR-ABL1-positive leukemia cell lines (K-562, BV-173, AR-230, and LAMA-84), with imatinib serving as a reference drug. Biological assays revealed distinct structure–activity relationships. Compounds 6 and 9 demonstrated superior activity against the K-562 cell line, while compounds 14 and 18 exhibited enhanced potency and higher ligand efficiencies (LEs) against BV-173 and AR-230 cells compared to imatinib. Selectivity assays further indicated favorable toxicity profiles of compounds 9 and 14 toward malignant versus non-malignant cells. Molecular docking studies supported these findings, showing that Fc substitution alters binding interactions within the c-Abl kinase ATP-binding site while retaining key stabilizing contacts. Computationally predicted LEs showed strong correlation with experimental data, especially for K-562 and LAMA-84 cells, confirming the kinase as a relevant target. Full article

Background and Objectives: A thorough comprehension of the essential molecules and related processes underlying the carcinogenesis, proliferation, and recurrence of acute myeloid leukemia (AML) is crucial. This study aimed to investigate the expression levels, diagnostic and prognostic significance and biological roles of Bcl-2-associated athanogene 4 (BAG4) in AML carcinogenesis. Materials and Methods: Gene expression profiles were analyzed using publicly available datasets, particularly GSE9476 and TCGA, using tools such as GEO2R, GEPIA2, UALCAN and TIMER2.0. The immune infiltration correlation was examined using the GSCA platform, while the function of BAG4 at the single-cell level was analyzed via CancerSEA. Protein–protein and gene–gene interaction networks were constructed using STRING and GeneMANIA, and enrichment analyses were performed using GO, KEGG and DAVID. Expression validation was performed using RT-qPCR in HL-60 (AML) and HaCaT (normal) cells, and ROC curve analysis evaluated the diagnostic accuracy. Results: BAG4 was significantly overexpressed in AML tissues and cell lines compared with healthy controls. High BAG4 expression was associated with poor overall survival and strong diagnostic power (AUC = 0.944). BAG4 was positively associated with immune cell infiltration and negatively associated with CD4+/CD8+ T and NK cells. At the single-cell level, BAG4 was associated with proliferation, invasion, and DNA repair functions. Functional network analysis showed that BAG4 interacted with apoptosis and necroptosis-related genes such as BCL2, BAG3 and TNFRSF1A and was enriched in pathways such as NF-κB, TNF signaling and apoptosis. Conclusions: BAG4 is overexpressed in AML and is associated with adverse clinical outcomes and immune modulation. It may play an important role in leukemogenesis by affecting apoptotic resistance and immune evasion. BAG4 has potential as a diagnostic biomarker and treatment target in AML, but further in vivo and clinical validation is needed. Full article

Background: Esophageal squamous cell carcinoma (ESCC) is a fatal malignant tumor. Several studies have demonstrated that immune checkpoint inhibitors can provide clinical benefits to patients with ESCC. However, the single-agent efficacy of these agents remains limited. Although combination therapies (e.g., radiotherapy, chemotherapy) can help to overcome immunotherapy resistance in ESCC, their severe side effects limit clinical application. This study aimed to explore new resistance mechanisms to immunotherapy in ESCC and identify novel molecular targets to overcome immunotherapy resistance. Methods: We employed immunohistochemistry staining to examine the p-FGFR1^Y654 in tumor samples obtained from 103 patients with ESCC, in addition to evaluating CD8+ T cell infiltration. In vitro expression, western blotting, CCK-8, 5-bromo-2′-deoxyuridine incorporation assays, and migration assays were used to confirm the impact of AZD4547 on p-FGFR1^Y654 expression and the proliferation and migration in ESCC cell lines. Through RNA sequencing analysis, databases such as the Cancer Genome Atlas (TCGA) and Gene Set Cancer Analysis (GSCA), and the reconstruction of transgenic mice using the humanized immune system, we validated the correlation between the expression of p-FGFR1^Y654 and CD8+ T cell infiltration. We also explored how p-FGFR1^Y654 recruits myeloid-derived suppressor cells (MDSCs) through the CXCL8–CXCR2 axis to suppress the therapeutic efficacy of immunotherapy in ESCC. Finally, the tumor-suppressive effects of AZD4547 combined with immunotherapy were confirmed in vivo in tumor-bearing mice with a humanized immune system. Results: We found that the inhibition of p-FGFR1^Y654 expression in ESCC can enhance CD8+ T cell infiltration by suppressing the CXCL8-–XCR2 recruitment of MDSCs. AZD4547, combined with immunotherapy, further promotes immunotherapeutic efficacy in ESCC. Conclusions: In conclusion, our study presents a promising model for combination therapy in ESCC immunotherapy. Full article

Anthracyclines have been clinically well established in cancer chemotherapy for decades. The main limitations of this drug class are the development of resistance and severe side effects. In the present investigation, we analyzed 30 anthracyclines in a panel of 59 cell lines of the National Cancer Institute, USA. The log₁₀IC₅₀ values varied from −10.49 M (3′-deamino-3′-(4″-(3″-cyano)morpholinyl)-doxorubicin, 1) to −4.93 M (N,N-dibenzyldaunorubicin hydrochloride, 30). Multidrug-resistant NCI-ADR-Res ovarian cancer cells revealed a high degree of resistance to established anthracyclines (between 18-fold to idarubicin (4) and 166-fold to doxorubicin (13) compared to parental, drug-sensitive OVCAR8 cells). The resistant cells displayed only low degrees of resistance (1- to 5-fold) to four other anthracyclines (7, 18, 28, 30) and were even hypersensitive (collaterally sensitive) to two compounds (1, 26). Live cell time-lapse microscopy proved the cross-resistance of the three chosen anthracyclines (4, 7, 9) on sensitive CCRF/CEM and multidrug-resistant CEM/ADR5000 cells. Structure–activity relationships showed that the presence of tertiary amino functions is helpful in avoiding resistance, while primary amines rather increased resistance development. An α-aminonitrile function as in compound 1 was favorable. Investigating the mRNA expression of 49 ATP-binding cassette (ABC) transporter genes showed that ABCB1/MDR1 encoding P-glycoprotein was the most important one for acquired and inherent resistance to anthracyclines. Molecular docking demonstrated that all anthracyclines bound to the same binding domain at the inner efflux channel side of P-glycoprotein with high binding affinities. Kaplan–Meier statistics of RNA sequencing data of more than 8000 tumor biopsies of TCGA database revealed that out of 23 tumor entities high ABCB1 expression was significantly correlated with worse survival times for acute myeloid leukemia, multiple myeloma, and hepatocellular carcinoma patients. This indicates that ABCB1 may serve as a prognostic marker in anthracycline-based chemotherapy regimens in these tumor types and a target for the development of novel anthracycline derivatives. Full article

Several of the integrin family of cell adhesion receptors have been popular targets for the development of anticancer agents, but with little clinical success to date. Cancer cells usually express multiple redundant integrins; one hypothesis for the lack of efficacy of current antagonists is their high selectivity for a single integrin. To address this, we developed a functional dual-β3-expressing cell model to investigate the effects of combined αIIbβ3/αvβ3 antagonism. We established that treating K562 chronic myeloid leukemia cells with 0.04 μM phorbol 12-myristate 13-acetate (PMA) for 40 h significantly upregulates functional αIIbβ3 and αvβ3 integrins. This optimized method provides a reliable platform for adhesion and detachment assays, enabling the characterization of dual integrin targeting strategies. Using this model, we demonstrate that combining αIIbβ3 and αvβ3 antagonists (GR144053 and cRGDfV) synergistically enhances inhibition of cell adhesion and promotes cell detachment compared to single-agent treatments. Our findings establish a reproducible approach for studying dual β3 integrin targeting, which can be used to investigate potential strategies for overcoming integrin redundancy in cancer therapeutics. Full article

Myelodysplastic syndromes (MDSs) comprise a diverse group of clonal hematopoietic stem cell disorders characterized by ineffective hematopoiesis, cytopenia in the peripheral blood, and an increased risk of transformation into acute myeloid leukemia (AML). Despite extensive research, the mechanisms underlying MDS pathogenesis remain unclear. In the present study, we explored the role of autophagy and apoptosis in the development of MDS and assessed the impact of azacitidine on these processes in vitro. First, we assessed the expression of proteins involved in both autophagic and apoptotic pathways in MDS patients with different prognoses. Furthermore, using the MDS-L cell line as a model, we investigated the in vitro effects of azacitidine treatment on these processes. We report that MDS, irrespective of risk classification, is associated with the dysregulation of autophagy and apoptosis. Notably, azacitidine treatment restored these cellular processes, accompanied by modulation of key signaling phosphoproteins. Overall, these findings provide evidence that impaired autophagy and apoptosis contribute to MDS pathogenesis and that azacitidine helps restore cellular homeostasis by activating both processes. Furthermore, our study highlights the potential therapeutic benefits of targeting these mechanisms and suggests that combining azacitidine with agents that modulate autophagy and apoptosis could enhance the treatment efficacy for MDS patients. Full article

Acute myeloid leukemia (AML) is a heterogeneous hematological malignancy associated with a poor prognosis. Activating mutations in the FLT3 gene occur in approximately 30% of AML cases, with internal tandem duplications in the juxtamembrane domain (FLT3-ITD; 75%) and mutations in the tyrosine kinase domain (FLT3-TKD; 25%). FLT3-ITD mutations are linked to poor prognosis and offer significant clinical predictive value, whereas the implications of FLT3-TKD mutations are less understood. The Hedgehog–Gli pathway is an established therapeutic target in AML, and emerging evidence suggests crosstalk between FLT3-ITD signaling and Gli expression regulation via non-canonical mechanisms. Post-translational modifications involving myristic and palmitic acids regulate various cellular processes, but their role in AML remains poorly defined. In this study, we investigated the role of fatty acid synthase (FASN), which synthesizes myristic and palmitic acids and catalyzes palmitoyl-acyltransferation, in regulating FLT3-ITD-Gli signaling. FASN knockdown using shRNA and the FASN inhibitor TVB-3166 was performed in FLT3-ITD-mutated AML cell lines (MOLM13, MV411) and Baf3-FLT3-ITD cells. The impact of FASN inhibition was assessed through Western blot and kinome profiling, while biological implications were evaluated by measuring cell viability and proliferation. FASN inhibition resulted in reduced levels of phospho-Akt (pAkt) and phospho-S6 kinase (pS6) and decreased expression of Hedgehog–Gli1, confirming non-canonical regulation of Gli by FLT3-ITD signaling. Combining TVB-3166 with the Gli inhibitor GANT61 significantly reduced the survival of MOLM13 and MV411 cells. Full article

The nucleoprotein structures known as telomeres provide genomic integrity by protecting the ends of chromosomes. Tumorigenesis is associated with alterations in telomere function and stability. This narrative review provides evidence of the potential prognostic value of telomere length and telomerase in leukemias. On the one hand, oxidative stress and mitochondrial dysfunction can accelerate telomere shortening, leading to higher susceptibility and the progression of leukemia. On the other hand, cytogenetic alterations (such as gene fusions and chromosomal abnormalities) and genomic complexity can result from checkpoint dysregulation, the induction of the DNA damage response (DDR), and defective repair signaling at telomeres. This review thoroughly outlines the ways by which telomere dysfunction can play a key role in the development and progression of four primary leukemias, including chronic lymphocytic leukemia (CLL), chronic myeloid leukemia (CML), and acute leukemias of myeloid or lymphoid origin, highlighting the potential prognostic value of telomere length in this field. However, telomerase, which is highly active in leukemias, can prevent the rate of telomere attrition. In line with this, leukemia cells can proliferate, suggesting telomerase as a promising therapeutic target in leukemias. For this reason, telomerase-based immunotherapy is analyzed in the fight against leukemias, leveraging the immune system to eliminate leukemia cells with uncontrolled proliferation. Full article

Biochanin A, a naturally occurring isoflavone derived from legumes, possesses anti-inflammatory, estrogenic, and anticancer activities. In this study, we investigated the cytotoxic effects and underlying molecular mechanisms of Biochanin A in acute myeloid leukemia (AML) cell lines, U937 and THP-1, using in vitro cytotoxicity assays, RNA sequencing, and bioinformatic analyses. Biochanin A induced dose-dependent apoptosis, as evidenced by caspase-7 activation and PARP1 cleavage. Over-representation analysis (ORA) revealed that differentially expressed genes (DEGs) were significantly enriched in pathways related to inflammatory responses, DNA replication, and cell cycle regulation. Gene set enrichment analysis (GSEA) further confirmed the upregulation of apoptosis- and inflammation-related pathways and the downregulation of MYC targets, cholesterol biosynthesis, and G2/M checkpoint gene sets. RT-qPCR analysis demonstrated that Biochanin A downregulated oncogenes such as RUNX1, BCL2, and MYC while upregulating CHOP (GADD153), CDKN1A (p21), and SQSTM1 (p62), contributing to apoptosis and cell cycle arrest across both cell lines. Notably, Biochanin A downregulated PLK1 and UHRF1 in THP-1 cells, indicating a disruption of mitotic progression and epigenetic regulation. In contrast, in U937 cells, Biochanin A upregulated TXNIP and downregulated CCND2, highlighting the involvement of oxidative stress and G1/S cell cycle arrest. These findings support the potential of Biochanin A as a promising therapeutic candidate for AML through both shared and distinct regulatory pathways. Full article

Background and Clinical Significance: Intermediate- to high-risk Myelodysplastic Syndrome (MDS), according to the Revised International Prognostic Scoring System (IPSS-M), confers a high risk of progression into acute myeloid leukemia. Treatment with hypomethylating agents, including azacitidine and decitabine, represents the current standard of care. In eligible patients, hypomethylating agents are used as a bridge for allogeneic stem cell transplantation, currently the only curative approach in these malignancies. The most common side effects of hypomethylating agents are myelosuppression, cutaneous injection site reactions (when azacitidine is given subcutaneously), and gastrointestinal symptoms. Uncommon, disabling, and long-lasting side effects represent a threat to effective treatment in this group of patients. Case Presentation: We describe the case of a 49-year-old male patient with IPSS-M intermediate-risk MDS, intended to receive first-line treatment with azacitidine followed by allogeneic stem cell transplantation. The first, late-onset azacitidine reaction was observed 48 h after the first exposure, with cutaneous and respiratory toxicity, followed by the late-onset recurrence of symptoms after azacitidine withdrawal and decitabine introduction. Conclusions: This case highlights atypical, disabling, and long-lasting drug reactions to two hypomethylating agents, with the persistence of hypersensitivity manifestations months after medication withdrawal. Full article

Background: Bone marrow (BM)-derived myeloid–lymphatic endothelial cell progenitors (M-LECPs) promote formation of tumor lymphatics that are responsible for metastasis to lymph nodes. The regenerative capacity of BM progenitors to other lineages is mediated through cell fusion, a process that delivers a pro-mitotic message directly to division-restricted cells. This suggested that M-LECPs might use a similar mechanism to induce division of lymphatic endothelial cells (LECs). Methods: To test this hypothesis, we determined expression of fusogenic markers in M-LECP produced in vitro and recruited to human or mouse tumors in vivo as well as quantified their fusion with LECs in both settings. Fusion in vivo was determined in female chimera mice grafted with male BM that have been implanted with MDA-MB-231 or EMT6 breast tumors. Co-staining for Y-chromosome and LEC-specific markers allowed us to quantify tumor lymphatic vessels fused with BM progenitors. Results: We found that both tumor-recruited and in-vitro-produced M-LECPs expressed multiple fusogenic regulators and possessed a significant fusogenic activity towards cultured and vessel-lining LECs. Y-chromosomes, a marker of fusion, were detected in nearly half of tumor lymphatics and were associated with mitotic division, vessel formation, and node metastasis. Both in vitro and in vivo assays showed dependency of fusion on Th2 and Toll-like receptor-4 (TLR4) pathways. Conclusions: This novel mechanism of tumor lymphatic formation triggered by fusion with BM myeloid–lymphatic progenitors suggests a variety of new targets for inhibition of metastatic spread. Full article

N-(2-chloro-5-(3-(pyridin-4-yl)-1H-pyrazolo [3,4-b]pyridin-5-yl)pyridin-3-yl)-4-fluorobenzenesulfonamide, namely, FD274, is a promising 7-azaindazole-based PI3K inhibitor candidate with high antitumor efficacy against acute myeloid leukemia and reduced cardiotoxicity in the zebrafish model. To advance its clinical translation, in this work, we conducted comprehensive assessments of the cardiotoxicity of FD274 and preliminarily investigated its synergistic antitumor effects with an FLT3 inhibitor, Gilteritinib. The cardiotoxicity profile of FD274, as well as its bioisostere FD268 (positive control), was evaluated using the C57BL/6 mouse model and the H9C2 cell line. The cardiotoxicity of FD274 after a consecutive 20-day treatment period was further assessed in an HL-60 xenograft mouse model. The synergistic cytotoxicity of FD274 with Gilteritinib was evaluated in the HL-60 cell line and the FLT3-ITD cell line MV-4-11. FD274 demonstrated lower adverse effects associated with cardiac dysfunction, oxidative stress, and myocardial injury in the C57BL/6 mouse model and in the H9C2 cell line as compared with FD268. Its negligible adverse effect was further validated in the HL-60 xenograft mice after the 20-day treatment process. Moreover, FD274 demonstrated a synergistic pro-apoptotic effect with Gilteritinib in both HL-60 and MV-4-11 cells. Our findings confirmed the low cardiotoxicity of FD274 and its great potential for combination therapy with Gilteritinib, warranting further development. Full article

The backbone of therapy for elderly patients with myelodysplastic syndromes and acute myeloid leukemia consists of hypomethylating agents 5-aza-2’-deoxycytidine (DAC) and 5-azacytidine (AZA). However, resistance frequently emerges during treatment. To investigate the mechanisms of resistance, we generated DAC-resistant variants of the acute myeloid leukemia cell lines, MOLM-13 and SKM-1, through their prolonged cultivation in increasing concentrations of DAC. The resistant cell variants, MOLM-13/DAC and SKM-1/DAC, exhibited cross-resistance to cytarabine and gemcitabine, but remained sensitive to AZA. Existing studies have suggested that the loss of deoxycytidine kinase (DCK) may play an important role in DAC resistance. DCK is critical for DAC activation, but the precise mechanisms of its downregulation remain incompletely understood. We identified a novel point mutation (A180P) in DCK, which results in acquired DAC resistance. Although the DCK mRNA was actively transcribed, the mutant protein was not detected in DAC-resistant cells. The transfection of HEK293 cells with the mutant DCK, combined with proteasomal inhibition, revealed rapid proteasomal degradation, establishing a mechanistic link between the A180P mutation and DCK loss, not previously described. This highlights the importance of also evaluating DCK at the protein and/or enzymatic activity levels in patients. The loss of functional DCK impairs the phosphorylation of deoxynucleosides, conferring resistance to DAC, gemcitabine, and cytarabine, but AZA, phosphorylated by uridine–cytidine kinase, remains effective and may represent a therapeutic alternative for patients with acquired DAC resistance. Full article