Combinatorial targeting of telomerase and DNA-PK induces synergistic apoptotic effects against Pre-B acute lymphoblastic leukemia cells.

BACKGROUND: Due to the high demand for novel approaches for leukemia-targeted therapy, this study investigates the impact of DNA-PK inhibitor NU7441 on the sensitivity of pre-B ALL cells to the telomerase inhibitor MST-312. METHODS: The study involved NALM-6 cells treated with MST-312 and NU7441, assessing their viability and metabolic activity using trypan blue and MTT assays. The study also evaluated apoptosis, gene expression changes, and DNA damage using flow cytometry, qRT-PCR, and micronucleus assays. The binding energy of MST-312 in the active site of telomerase was calculated using molecular docking. RESULTS: The study's findings revealed a synergistic decline in both cell viability and metabolic activity in NALM-6 cells when exposed to the combined treatment of MST-312 and NU7441, and this decrease occurred without any adverse effects on healthy PBMC cells. Furthermore, the combination treatment exhibited a significantly higher induction of apoptosis than treatment with MST-312 alone, as observed through flow cytometry assay. qRT-PCR analysis revealed that this enhanced apoptosis was associated with a notable downregulation of Bcl-2 expression and an upregulation of Bax gene expression. Moreover, the combination therapy decreased expression levels of hTERT and c-Myc genes. The micronucleus assay indicated that the combination treatment increased DNA damage in NALM-6 cells. Also, a good conformation between MST-312 and the active site of telomerase was revealed by docking data. CONCLUSIONS: The study suggests that simultaneous inhibition of telomerase and DNA-PK in pre-B ALL presents a novel targeted therapy approach.

Extracellular microvesicles: biologic properties, biogenesis, and applications in leukemia.

Microvesicles are cellular membrane vesicles of which size is limited to 30-1000 nm. Almost all cells release them in response to activation signals and apoptosis. Their ability for intercellular communication and enhancement of potential for information exchange (between them) has attracted much interest. Their content is affected by the content of the mother cell, which can help identify their origin. Furthermore, these particles can change the physiology of the target cells by transferring a set of molecules to them and changing the epigenetics of the cells by transferring DNA and RNA. These changes can be induced in cells close to the mother and distant cells. Significant activities of these microvesicles are known both in physiological and pathologic conditions. In this regard, we have reviewed these small particle elements, their contents, and the way of synthesis. Finally, we discussed their current known roles to reveal more potential applications in leukemia.

Differential Expression of the hTERT Gene in Umbilical Cord-Derived Mesenchymal Stem Cells Cocultured with B Cell Precursor Leukemia Cell Microparticles or CD41+/CD61+ Platelet Microparticles.

Several investigations are being done to increase the short lifetime of mesenchymal stem cells (MSCs). One of the crucial genes involved in the immortalization of MSCs, hTERT (human telomerase reverse transcriptase), is activated in most publications using viral-based techniques. In this work, we investigated the use of platelet-derived (PMPs) and B cell precursor leukemia-derived microparticles as a nonviral method to trigger and compare the expression of the hTERT gene in MSCs. MSCs were extracted from the umbilical cord for the current investigation and identified using a flow cytometry approach and an inverted microscope. The Nalm-6 cell line and platelet concentrate were used to isolate microparticles (MPs). MSCs and MPs were cocultured for 14 days at 25-, 50-, and 100 µg/ml concentrations. qRT-PCR was used to research the expression of the hTERT gene. SPSS 26.0's t test was used to compare the outcomes. After coculture with platelet MPs, MSCs had higher levels of hTERT gene expression than the control group. In contrast, this gene's expression was concurrently decreased in MSCs exposed to MPs generated from Nalm-6. We demonstrated that following 14-day treatment, PMP significantly boosted the hTERT gene expression in MSCs, while the Nalm-6 MPs lowered the gene expression. However, additional studies are necessary due to the stability of hTERT gene expression and the immortalization of MSCs following exposure.

Promising anti-leukemic effect of Zataria multiflora extract in combination with doxorubicin to combat acute lymphoblastic leukemia cells (Nalm-6) (in vitro and in silico).

One of the heterogeneous hematologic malignancies of the lymphocyte precursors is ALL. ALL has two incidence peaks that were determined in 2-5 years children and 60 years old adults. Cardiotoxicity of chemotherapeutic drugs is one of important side effects which may occur during or after chemotherapy period. The aim of this study was to evaluate the effect of ZME, Dox, and combinations on Nalm-6 cells. In this vein, the cell viability was assessed by Trypan blue and MTT assay. Evaluation of apoptosis was also analyzed by Annexin-V/PI staining. Moreover, the expression of Bax, Bcl-2, Bcl-xl, hTERT, c-Myc, P53, and P21 genes was detected by Real-Time PCR. Molecular docking as an in-silico method was performed for Bcl-2 and Bcl-xl proteins as well. Our achievements indicated that ZME had dose-dependent effect on Nalm-6 cells and ZME synergistically potentiated Dox effect. The expression of Bax, P53 and P21 genes increased although the expression of Bcl-2 genes decreased when cells treated with ZME/ Dox combination. Molecular docking showed the interactions of carvacrol and thymol in the active cavities of BCL2 and BCL-xl. Regarding to present study, ZME could be utilized as a combinatorial and potential drug for leukemic patients, which is under the treatment by Dox due to reducing the chemotherapy drug doses.