Objective: This study aimed to investigate the role and mechanism of circular RNA PVT1 (circPVT1) in patients with acute myeloid leukemia (AML).
Materials and Methods: The expression of circPVT1 in 23 patients with de novo AML (not acute promyelocytic leukemia, not APL) and cell lines were detected by RT-qPCR. Loss of function assays were carried out to explore the influence of silenced circPVT1 on the proliferation, migration, and apoptosis in the THP-1 cell line. CCK-8 assays, transwell assays, and annexin V/PI staining assays were performed to assess proliferation, migration, and apoptosis, respectively.
Results: CircPVT1 was highly expressed in AML patients and myeloid cell lines compared to healthy controls. Higher expression of circPVT1 was related to shorter overall survival (OS) and relapse-free survival (RFS) in AML patients. Cell viability and migration were inhibited and apoptosis was increased when circPVT1 was knocked down in THP-1 cells. Knockdown of circPVT1 resulted in marked suppression of c-Myc protein with no significant change in mRNA levels. We also found that circPVT1 knockdown markedly increased the phosphorylation of c-Myc Thr-58, which was responsible for c-Myc degradation. Silencing of c-Myc caused a significant decrease in CXCR4 mRNA and protein expression, whereas the overexpression of c-Myc caused the opposite result, suggesting that CXCR4 is a target molecule of c-Myc. Finally, we found that overexpression of c-Myc could partially reverse circPVT1 knockdown-induced anti-tumor effects on THP-1 cells in vitro.
Conclusion: Our findings showed that circPVT1 was highly expressed in AML patients and was related to shorter OS and RFS. CircPVT1 may exert an oncogenic effect in THP-1 cells by stabilizing c-Myc protein expression and downstream target CXCR4 expression. These data indicate that circPVT1 may be a promising therapeutic target for AML.

Objective: This study was undertaken to evaluate the long-term clinical efficacy of epoetin alfa and darbepoetin alfa in patients with myelodysplastic syndrome (MDS) in a real-life setting.
Materials and Methods: A total of 204 patients with low-risk or intermediate-1-risk MDS who received epoetin alfa or darbepoetin alfa were included. Hemoglobin levels and transfusion needs were recorded before treatment and at 12 months, 24 months, 36 months, and 48 months of treatment.
Results: At the 36-month (p=0.025) and 48-month (p=0.022) visits, epoetin alfa yielded significantly higher hemoglobin levels compared to darbepoetin alfa. Transfusion needs were also significantly lower with epoetin alfa compared to darbepoetin alfa at 24 months (p=0.012) and in the low-risk group compared to the intermediate-risk group at 24 months (p=0.018), 36 months (p=0.025), and 48 months (p<0.001). Treatment response rates at the 24-month, 36-month, and 48-month visits in the epoetin alfa (43.0%, 33.6%, and 27.1%), darbepoetin alfa (29.9%, 22.7%, and 16.5%), low-risk (39.3%, 30.0%, and 26.0%), and intermediate-risk (29.6%, 24.1%, and 11.1%) groups were lower than those obtained at 12 months, and the values differed significantly for the 36-month and 48-month visits with values ranging from p<0.05 to p<0.001.
Conclusion: This real-life long-term ESA extension study investigated the clinical efficacy of epoetin alfa and darbepoetin alfa for up to 48 months, revealing that treatment efficacy reached a plateau starting from the 24th month of therapy with a continuing decrease in treatment response rates regardless of treatment type, risk status, or gender. Nonetheless, significantly higher hemoglobin levels and marked improvement in transfusion needs were evident in epoetintreated patients compared to darbepoetin-treated patients and in the low-risk group compared to the intermediate-risk group.

Objective: Chronic myeloid leukemia (CML) is a disease caused by the acquisition of BCR-ABL1 fusion in hematopoietic stem cells. In this study, we focus on the oncofetal ENOX2 protein as a potential secretable biomarker in CML.
Materials and Methods: We used cell culture, western blot, quantitative RT-PCR, ELISA, transcriptome analyses, and bioinformatics techniques to investigate ENOX2 mRNA and protein expression.
Results: Western blot analyses of UT-7 and TET-inducible Ba/F3 cell lines demonstrated the upregulation of the ENOX2 protein. BCR-ABL1 was found to induce ENOX2 overexpression in a kinase-dependent manner. We confirmed increased ENOX2 mRNA expression in a cohort of CML patients at diagnosis. In a series of CML patients, ELISA assays showed a highly significant increase of ENOX2 protein levels in the plasma of patients with CML compared to controls. Reanalyzing the transcriptomic dataset confirmed ENOX2 mRNA overexpression in the chronic phase of the disease. Bioinformatic analyses identified several genes whose mRNA expressions were positively correlated with ENOX2 in the context of BCR-ABL1. Some of them encode proteins involved in cellular functions compatible with the growth deregulation observed in CML.
Conclusion: Our results highlight the upregulation of a secreted redox protein in a BCR-ABL1-dependent manner in CML. The data presented here suggest that ENOX2, through its transcriptional mechanism, plays a significant role in BCR-ABL1 leukemogenesis.

Objective: Hemophilia A is an X-linked recessive bleeding disorder caused by a deficiency of plasma coagulation factor VIII (FVIII), and it accounts for about 80%-85% of all cases of hemophilia. Plasma-derived therapies or recombinant FVIII concentrates are used to prevent and treat the bleeding symptoms along with FVIIImimicking antibodies. Recently, the European Medicines Agency granted conditional marketing approval for the first gene therapy for hemophilia A. The aim of this study was to determine the effectiveness of coagulation in correcting FVIII deficiency with FVIII-secreting transgenic mesenchymal stem cells (MSCs).
Materials and Methods: A lentiviral vector encoding a B domaindeleted FVIII cDNA sequence with CD45R0 truncated (CD45R0t) surface marker was designed to develop a transgenic FVIII-expressing primary cell line by transducing MSCs. The efficacy and functionality of the FVIII secreted from the MSCs was assessed with anti-FVIII ELISA, CD45R0t flow cytometry, FVIII western blot, and mixing test analysis in vitro.
Results: The findings of this study showed that the transgenic MSCs maintained persistent FVIII secretion. There was no significant difference in FVIII secretion over time, suggesting stable FVIII expression from the MSCs. The functionality of the FVIII protein secreted in the MSC supernatant was demonstrated by applying a mixing test in coagulation analysis. In the mixing test analysis, FVIIIdeficient human plasma products were mixed with either a saline control or FVIII-secreted MSC supernatant. The mean FVIII level of the saline control group was 0.41±0.03 IU/dL, whereas the mean level was 25.41±33.38 IU/dL in the FVIII-secreting MSC supernatant mixed group (p<0.01). The mean activated partial thromboplastin time (aPTT) of the saline control group was 92.69±11.38 s, while in the FVIII-secreting MSC supernatant mixed group, the mean aPTT level decreased to 38.60±13.38 s (p<0.001).
Conclusion: The findings of this in vitro study suggest that the new method presented here is promising as a possible treatment for hemophilia A. Accordingly, a study of FVIII-secreting transgenic MSCs will next be initiated in a FVIII-knockout animal model.