UNASSIGNED: The PI3K/AKT/mTOR signaling pathway plays a significant role in the development of T-cell acute lymphoblastic leukemia (T-ALL). Rapamycin is a potential therapeutic strategy for hematological malignancies due to its ability to suppress mTOR activity. Additionally, microRNAs (miRNAs) have emerged as key regulators in T-ALL pathophysiology and treatment. This study aimed to investigate the combined effects of rapamycin and miRNAs in inhibiting the PI3K/AKT/mTOR pathway in T-ALL cells.
UNASSIGNED: Bioinformatic algorithms were used to find miRNAs that inhibit the PI3K/AKT/mTOR pathway. Twenty-five bone marrow samples were collected from T-ALL patients, alongside five control bone marrow samples from non-leukemia patients. The Jurkat cell line was chosen as a representative model for T-ALL. Gene and miRNA expression levels were assessed using quantitative real-time PCR (qRT-PCR). Two miRNAs exhibiting down-regulation in both clinical samples and Jurkat cells were transfected to the Jurkat cell line to investigate their impact on target gene expression. Furthermore, in order to evaluate the potential of combination therapy involving miRNAs and rapamycin, apoptosis and cell cycle assays were carried out.
UNASSIGNED: Six miRNAs (miR-3143, miR-3182, miR-99a/100, miR-155, miR-576-5p, and miR-501- 3p) were predicted as inhibitors of PI3K/AKT/mTOR pathway. The expression analysis of both clinical samples and the Jurkat cell line revealed a simultaneous downregulation of miR-3143 and miR-3182. Transfection investigation demonstrated that the exogenous overexpression of miR-3143 and miR-3182 can effectively inhibit PI3K/AKT/mTOR signaling in the Jurkat cell line. Moreover, when used as a dual inhibitor along with rapamycin, miR-3143 and miR-3182 significantly increased apoptosis and caused cell cycle arrest in the Jurkat cell line.
UNASSIGNED: These preliminary results highlight the potential for improving T-ALL treatment through multi-targeted therapeutic strategies involving rapamycin and miR-3143/miR-3182.

T-cell acute lymphoblastic leukemia (T-ALL), a heterogeneous hematological malignancy, is caused by the developmental arrest of normal T-cell progenitors. The development of targeted therapeutic regimens is impeded by poor knowledge of the stage-specific aberrances in this disease. In this study, we performed multi-omics integration analysis, which included mRNA expression, chromatin accessibility, and gene-dependency database analyses, to identify potential stage-specific druggable targets and repositioned drugs for this disease. This multi-omics integration helped identify 29 potential pathological genes for T-ALL. These genes exhibited tissue-specific expression profiles and were enriched in the cell cycle, hematopoietic stem cell differentiation, and the AMPK signaling pathway. Of these, four known druggable targets (CDK6, TUBA1A, TUBB, and TYMS) showed dysregulated and stage-specific expression in malignant T cells and may serve as stage-specific targets in T-ALL. The TUBA1A expression level was higher in the early T cell precursor (ETP)-ALL cells, while TUBB and TYMS were mainly highly expressed in malignant T cells arrested at the CD4 and CD8 double-positive or single-positive stage. CDK6 exhibited a U-shaped expression pattern in malignant T cells along the naïve to maturation stages. Furthermore, mebendazole and gemcitabine, which target TUBA1A and TYMS, respectively, exerted stage-specific inhibitory effects on T-ALL cell lines, indicating their potential stage-specific antileukemic role in T-ALL. Collectively, our findings might aid in identifying potential stage-specific druggable targets and are promising for achieving more precise therapeutic strategies for T-ALL.

The present study aimed to investigate the anti-leukemic effects of dihydroartemisinin (DHA) on T-cell acute lymphoblastic leukemia (T-ALL) cell lines, Jurkat and Molt-4, and the underlying mechanisms. Cell Counting Kit-8 was performed to measure cell viability. Cell apoptosis and cell cycle distribution were assessed by flow cytometry. The expression levels of ATF4 and CHOP mRNA were assessed by reverse transcription-quantitative PCR, while the protein abundance of SLC7A11, GPX4, ATF4 and CHOP was determined by western blotting. Moreover, malondialdehyde, glutathione (GSH) and reactive oxygen species (ROS) assays were used to detect the levels of ferroptosis. The results showed that DHA suppressed T-ALL cell viability in vitro, and induced cell cycle arrest at S or G2/M phase. DHA also induced ROS burst, activated endoplasmic reticulum (ER) stress, disrupted the system Xc--GSH-GSH peroxidase 4 antioxidant system, and increased lipid peroxide accumulation, resulting in cell death. By contrast, the pharmacological inhibition of ferroptosis alleviated DHA-induced cell death, confirming that DHA induces T-ALL cell death via ferroptosis. Mechanistically, the effect of DHA on ferroptosis was partly mediated by downregulating SLC7A11 and upregulating the ATF4-CHOP signaling pathway, which is associated with ER stress. These results indicated that DHA may induce ferroptosis in T-ALL cell lines and could represent a promising therapeutic agent for treating T-ALL.

T-cell acute lymphoblastic leukemia (T-ALL) is a hematologic heterogeneous disease. This study explored the mechanism of specificity protein 1/3 (Sp1/3) in T-ALL cells through β-catenin by acting as targets of miR-495-3p. Expression levels of miR-495-3p, Sp1, Sp3, and β-catenin in the serum from T-ALL children patients, healthy controls, and the T-ALL cell lines were measured. The cell proliferation ability and apoptosis rate were detected. Levels of proliferation-related proteins proliferating cell nuclear antigen (PCNA)/cyclinD1 and apoptosis-related proteins B-cell lymphoma-2 associated X protein (Bax)/B-cell lymphoma-2 (Bcl-2) were determined. The binding of Sp1/3 and β-catenin promoter and the targeted relationship between miR-495-3p with Sp1/3 were analyzed. Sp1/3 were upregulated in CD4+ T-cells in T-ALL and were linked with leukocyte count and risk classification. Sp1/3 interference prevented proliferation and promoted apoptosis in T-ALL cells. Sp1/3 transcription factors activated β-catenin expression. Sp1/3 enhanced T-ALL cell proliferation by facilitating β-catenin expression. miR-495-3p targeted and repressed Sp1/3 expressions. miR-495-3p overexpression inhibited T-ALL cell proliferation and promoted apoptosis. Conjointly, Sp1/3, as targets of miR-495-3p limit apoptosis and promote proliferation in T-ALL cells by promoting β-catenin expression.

UNASSIGNED: T-cell acute lymphoblastic leukemia (T-ALL) is a form of leukemia characterized by the proliferation of immature T lymphocytes. NOTCH1 is one of the most frequently mutated genes in T-ALL. NOTCH1 expression in T-cell development depends on plant homeodomain finger protein 6 (PHF6), which plays a tumor suppressor role in T-ALL. Several studies have shown that PHF6 expression is essential for NOTCH1 expression. Therefore, whether posttranslational modification of PHF6 plays a role in the regulation of NOTCH1 expression and T-ALL cell line proliferation was investigated herein.
UNASSIGNED: The amino acid sequence of PHF6 was analyzed and it was found that a putative protein kinase A (PKA) phosphorylation motif RDRS199 was conserved in several vertebrate species and the S199 site was expected to be phosphorylated according to the PhosphoSite database. Therefore, an eukaryotic expression vector of human PHF6 was constructed, and the codon 199 was changed to the codon encoding the nonphosphorylatable alanine and the phosphorylation-mimicking aspartic acid via site-directed mutagenesis. After confirming the ectopic expressions of the PHF6 vectors by western blot analysis, the effects of these proteins were identified on the NOTCH1 expression using western blot analysis, leukemic cell proliferation using MTT assay, and expressions of the cell surface markers of T-cells using flow cytometry.
UNASSIGNED: The ectopic expression of wild-type PHF6 stimulated the formation of CD4 + T-cells. While the expression of the wild-type PHF6 suppressed the growth of the leukemic cell line, this effect was diminished in both the alanine and aspartic acid mutants of PHF6. In addition, both mutants also seemed to negatively affect the NOTCH1 expression, although the effect of the alanine mutant was more severe.
UNASSIGNED: Taken together, the different biological activities exerted by the conserved S199 phosphorylation-site mutants shown in this study implicate that signaling pathway(s) leading to differential phosphorylation of this residue may have a substantial effect on the activity of PHF6, and thus may constitute a potential therapeutic target in T-ALL.

BACKGROUND: Identifying patients with high-risk T-cell acute lymphoblastic leukemia (T-ALL) is crucial for personalized therapy; however, the lack of robust biomarkers hinders prognosis assessment. To address this issue, our study aimed to screen and validate genes whose expression may serve as predictive indicators of outcomes in T-ALL patients while also investigating the underlying molecular mechanisms.
METHODS: Differentially expressed genes (DEGs) between T-ALL patients and healthy controls were identified by integrating data from three independent public datasets. Functional annotation of these DEGs and protein-protein interactions were also conducted. Further, we enrolled a prospective cohort of T-ALL patients (n = 20) at our center, conducting RNA-seq analysis on their bone marrow samples. Survival-based univariate Cox analysis was employed to identify gene expressions related to survival, and an intersection algorithm was sequentially applied. Furthermore, we validated the identified genes using cases from the Therapeutically Applicable Research to Generate Effective Treatments database, plotting Kaplan-Meier curves for secondary validation.
RESULTS: Through the integration of survival-related genes with DEGs identified in T-ALL, our analysis revealed six T-ALL-specific genes, the expression levels of which were linked to prognostic value. Notably, the independent prognostic value of SLC40A1 and TES expression levels was confirmed in both an external cohort and a prospective cohort at our center.
CONCLUSIONS: In summary, our preliminary study indicates that the expression levels of TES and SLC40A1 genes show promise as potential indicators for predicting survival outcomes in T-ALL patients.

CD99 was demonstrated to be a potential target for antibody therapy on T-acute lymphoblastic leukemia (T-ALL). The ligation of CD99 by certain monoclonal antibodies (mAbs) induced T-ALL apoptosis. However, the molecular basis contributing to the apoptosis of T-ALL upon anti-CD99 mAb engagement remains elusive. In this study, using our generated anti-CD99 mAb clone MT99/3 (mAb MT99/3), mAb MT99/3 engagement strongly induced apoptosis of T-ALL cell lines, but not in non-malignant peripheral blood cells. By transcriptome analysis, upon mAb MT99/3 ligation, 13 apoptosis-related genes, including FOS, TNF, FASLG, BCL2A1, JUNB, SOCS1, IL27RA, PTPN6, PDGFA, NR4A1, SGK1, LPAR5 and LTB, were significantly upregulated. The epitope of CD99 recognized by mAb MT99/3 was then identified as the VDGENDDPRPP at residues 60-70 of CD99, which has never been reported. To the best of our knowledge, this is the first transcriptome data conducted in T-ALL with anti-CD99 mAb engagement. These findings provide new insights into CD99 implicated in the apoptosis of T-ALL. The identification of a new epitope and apoptosis-related genes that relate to the induction of apoptosis by mAb MT99/3 may serve as a new therapeutic target for T-ALL. The anti-CD99 mAb clone MT99/3 might be a candidate for further development of a therapeutic antibody for T-ALL therapy.

T-cell acute lymphoblastic leukemia/lymphoma (T-ALL/LBL) is a rare and aggressive leukemia. Philadelphia chromosome-positive cytogenetic abnormality is most common in CML. It is difficult to differentiate between de novo Ph+ T-ALL/LBL and T-cell lymphoblastic crises of CML. We present a case of adult Ph+ T-ALL/LBL with a likely history of antecedent CML. Initially thought to be a case of chronic-phase CML, a diagnostic quandary led to the pursuit of a lymph node biopsy that established the diagnosis of Ph+ T-LBL or T lymphoblastic blast crisis of CML, a clinical presentation extremely rare and only the second of its kind from our review of the literature. The patient was treated with an intensive chemotherapy regimen for over a year due to persistent minimal residual disease (MRD) positivity indicating aggressive disease.

Gamma delta (γδ) T-cell acute lymphoblastic leukemia/lymphoma (T-ALL) is a rare, aggressive subtype of T-lymphoid leukemia that accounts for only 9-12% of all T-ALL cases. Herein, we report the case of an 8-year-old boy who presented with facial swelling, shortness of breath, and progressive cervical and axillary lymphadenopathy. Pathological examination, flow cytometry (Navios, Beckman Coulter ClearLLab 10C 10-color T-cell panel [containing FITC-labeled TCR γδ antibody]), chromosomal analysis, interphase FISH, and targeted DNA-based NGS (34-gene Illumina TruSeq Myeloid Panel) were performed. Flow cytometry evaluation of a lymph node biopsy specimen revealed an immature T-cell population positive for CD4, CD3, CD2 (subset positive), CD5, CD7, CD38, CD1a, cytoplasmic terminal deoxynucleotidyl transferase (cyto-TdT), CD30 (subset positive), and T-cell receptor (TCR) gamma delta (γδ). Microscopic examination of an enlarged lymph node and bone marrow showed involvement by a dense, diffuse, neoplastic infiltrate. Interphase FISH revealed a copy number loss of PDGFRB (5q32) in 90.5% of interphase nuclei. Targeted DNA-based NGS detected a tier II oncogenic variant in NOTCH1 (c.7375C > T, p.Gln2459Ter) at a VAF of 21%. This case of γδ T-ALL highlights a rare entity and adds to the literature, albeit scant, which may aid in better recognition and classification.

Monoclonal antibodies (mAbs) are an effective drug for targeted immunotherapy in several cancer types. However, so far, no antibody has been successfully developed for certain types of cancer, including T-cell acute lymphoblastic leukemia (T-ALL). T-ALL is an aggressive hematologic malignancy. T-ALL patients who are treated with chemotherapeutic drugs frequently relapse and become drug resistant. Therefore, antibody-based therapy is promising for T-ALL treatment. To successfully develop an antibody-based therapy for T-ALL, antibodies that induce death in malignant T cells but not in nonmalignant T cells are required to avoid the induction of secondary T-cell immunodeficiency. In this review, CD99 tumor associated antigen, which is highly expressed on malignant T cells and lowly expressed on nonmalignant T cells, is proposed to be a potential target for antibody therapy of T-ALL. Since certain clones of anti-CD99 mAbs induce apoptosis only in malignant T cells, these anti-CD99 mAbs might be a promising antibody drug for the treatment of T-ALL with high efficiency and low adverse effects. Moreover, over the past 25 years, many clones of anti-CD99 mAbs have been studied for their direct effects on T-ALL. These outcomes are gathered here.