Allogeneic stem cell transplantation for patients with myelodysplastic syndromes

Bi-targeting of thioredoxin 1 and telomerase by thiotert promotes cell death of myelodysplastic syndromes and lymphoma

Thioredoxin1 (TRX1) and telomerase are both attractive oncology targets that are tightly implicated in tumor initiation and development. Here, we reported that the 6-dithio-2-deoxyguanosine analog thiotert exhibits an effective cytotoxic effect on myelodysplastic syndromes (MDS) cell SKM-1 and lymphoma cell U-937. Further studies confirmed that thiotert effectively disrupts cellular redox homeostasis, as evidenced by elevated intracellular reactive oxygen species (ROS) levels, increased MnSOD, accelerated DNA impairment, and activated apoptosis signal. Mechanistically, our present study revealed that thiotert treatment effectively inhibited the function of the TRX1/TRXR1 system and telomerase reverse transcriptase (TERT), rendering oxidative damage and impairment of telomeres. Meanwhile, pharmacological administration of glutathione (GSH), N-acetylcysteine (NAC), and mitoquinone (MitoQ), or genetic overexpression of TRX1 or TERT in MDS and cells could dampen the toxicity caused by thiotert. Remarkably, the in vivo mouse model of MDS demonstrated that thiotert administration exhibited greater efficacy in tumor reduction compared to the conventional chemotherapy drug cytarabine. Collectively, these results provide experimental insights into the mechanism of thiotert-induced MDS and lymphoma cell death and unveil that thiotert may be an effective and promising new drug for future MDS and lymphoma treatment.

The prophylactic application of low-dose rabbit antithymocyte globulin in matched siblings HSCT with high-risk factors for graft-versus-host disease

Relapse and graft-versus-host disease (GVHD) are currently the predominant causes of mortality post allogeneic hematopoietic stem cell transplantation (allo-HSCT). The contentious use of antithymocyte globulin (ATG) for preventing GVHD in matched sibling HSCT scenarios has been a topic of significant debate. A retrospective analysis was conducted on matched sibling HSCT cases with high-risk factors for GVHD in our center from January 2018 to June 2023. Our assessment revealed that the group administered with ATG exhibited a 30 % incidence of acute GVHD (aGVHD), in contrast to 81.8 % in the non-ATG cohort (P = 0.037) among matched sibling HSCT cases with high GVHD risk factors. Furthermore, chronic GVHD (cGVHD) occurred in 20 % of the ATG group and 72.7 % of the non-ATG group (P = 0.03). Notably, the administration of ATG did not significantly impact disease relapse (p = 0.149), infection rates (p = 0.64), granulocyte recovery time (p = 0.15), platelet recovery time (p = 0.12), overall survival (p = 0.889), or disease-free survival time (p = 0.787). The use of rabbit antithymocyte globulin (r-ATG) at a 5 mg/kg dosage demonstrated a notable reduction in aGVHD and cGVHD incidences within sibling matched HSCT cases with high-risk factors for GVHD, without increasing rates of disease recurrence or infections. These findings highlight the potential benefit of using low-dose r-ATG in high-risk of GVHD sibling matched allogeneic HSCTs, although further validation with a larger cohort is necessary.

Comparative analysis of immunological changes following realgar and arsenic trioxide treatments in a murine model of myelodysplastic syndrome

BACKGROUND

Myelodysplastic syndrome (MDS) is a prevalent hematological neoplastic disorder in clinics and its immunopathogenesis has garnered growing interest. Oral and intravenous arsenic agents have long been used to treat hematological malignancies. The main component of oral arsenic is realgar (arsenic disulfide), while arsenic trioxide is the main component of intravenous arsenic.

METHODS

This study aimed to assess the effects of ATO and Realgar on the enhancement of peripheral blood, drug safety, and T cell immune status in the NUP98-HOXD13 (NHD13) mice model of MDS, specifically in the peripheral blood, spleen, and liver.

RESULTS

The study findings indicate that realgar and arsenic trioxide (ATO) can improve peripheral hemogram in mice, whereas realgar promotes higher peripheral blood cell production than ATO. Furthermore, the clinical administration method and dose did not cause significant toxicity or side effects and thus can be considered safe. Coexistence and interconversion of hyperimmune function and immunosuppression in mice were also observed in this study. In addition, there were interactions between immune cells in the peripheral blood, spleen, and liver to regulate the immune balance of the body and activate immunity via T-cell activation.

CONCLUSION

In summary, oral and intravenous arsenic agents are beneficial in improving peripheral hemogram and immunity in mice.

Comparison of Melphalan Dose in Patients with Myelodysplastic Syndrome Undergoing Allogeneic Transplantation with Reduced-Intensity Conditioning

The present study compared lower-dose melphalan (80 mg/m2, FM80) and higher-dose melphalan (140 mg/m2, FM140) when administering reduced-intensity conditioning with fludarabine in adult patients with myelodysplastic syndrome (MDS) undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). We retrospectively analyzed nationwide registry data (2006 to 2019) and compared transplant outcomes between the 2 groups. Ninety-two patients (median age, 61 [interquartile range, 56 to 65] years) were assigned to the FM80 and FM140 groups by propensity score matching. The 3-year overall survival (OS) rate in the FM140 group (63.9%; 95% confidence interval [CI], 52.9% to 73.0%) was significantly higher than that in the FM80 group (54.2%; 95% CI, 37.1% to 52.1%) (P = .038). The FM140 group had a nonsignificantly (P = .095) lower 3-year cumulative incidence of relapse (15.5%; 95% CI, 8.9% to 23.8% versus 26.0%; 95% CI, 17.3% to 35.5%). The 3-year cumulative incidences of nonrelapse mortality were 22.3% (95% CI, 14.1% to 31.8%) and 23.7% (95% CI, 15.4% to 33.2%) in the FM80 and FM140 groups, respectively (P = .49). The beneficial effect of FM140 was more evident in patients with a poor cytogenetic risk. Our findings suggest the superiority of FM140 in patients with MDS undergoing allo-HSCT, especially in high-risk patients.

Role of reactive oxygen species in myelodysplastic syndromes

Reactive oxygen species (ROS) serve as typical metabolic byproducts of aerobic life and play a pivotal role in redox reactions and signal transduction pathways. Contingent upon their concentration, ROS production not only initiates or stimulates tumorigenesis but also causes oxidative stress (OS) and triggers cellular apoptosis. Mounting literature supports the view that ROS are closely interwoven with the pathogenesis of a cluster of diseases, particularly those involving cell proliferation and differentiation, such as myelodysplastic syndromes (MDS) and chronic/acute myeloid leukemia (CML/AML). OS caused by excessive ROS at physiological levels is likely to affect the functions of hematopoietic stem cells, such as cell growth and self-renewal, which may contribute to defective hematopoiesis. We review herein the eminent role of ROS in the hematological niche and their profound influence on the progress of MDS. We also highlight that targeting ROS is a practical and reliable tactic for MDS therapy.

The prognosis and risk factors for patients with complex karyotype myelodysplastic syndrome undergoing allogeneic haematopoietic stem cell transplantation

Allogeneic haematopoietic stem cell transplantation (HCT) is the curative treatment for myelodysplastic syndrome with a complex karyotype (CK-MDS). However, only a few studies have been limited to patients with CK-MDS undergoing allogeneic HCT. This study aimed to identify the risk factors for patients with CK-MDS undergoing allogeneic HCT. We included 691 patients with CK-MDS who received their first allogeneic HCT. The overall survival (OS) was the primary end-point, estimated using the Kaplan-Meier method. Prognostic factors were identified using a Cox proportional hazards model. The 3-year OS was 29.8% (95% confidence interval [CI]: 26.3-33.3). In the multivariable analysis, older age (hazard ratio [HR]: 1.44, 95% CI: 1.11-1.88), male sex (HR: 1.38, 95% CI: 1.11-1.71), poor haematopoietic cell transplant comorbidity index (HR: 1.47, 95% CI: 1.20-1.81), red blood cell transfusion requirement (HR: 1.58, 95% CI: 1.13-2.20), platelet transfusion requirement (HR: 1.85, 95% CI: 1.46-2.35), not-complete remission (HR: 1.55, 95% CI: 1.16-2.06), a high number of karyotype abnormality (HR: 1.63, 95% CI: 1.18-2.25) and monosomal karyotype (HR: 1.49, 95% CI: 1.05-2.12) were significantly associated with OS. Thus, the 3-year OS of allogeneic HCT was 29.8% in patients with CK-MDS, and we identified risk factors associated with poor OS.

Hematopoietic Stem Cell Transplantation in the Management of Myelodysplastic Syndrome: A Retrospective, Current, and Future Perspective

Myelodysplastic syndrome (MDS) is a clonal disorder that affects hematopoietic stem cells (HSCs), primarily occurring in the elderly population. Lower-risk MDS is characterized by a decrease in blood cells, whereas higher-risk MDS is associated with an increased risk of transformation to acute myeloid leukemia (AML). Currently, the treatment of MDS is still unsatisfactory, although demethylating agents, azacitidine (AZA), and decitabine (Dec) have been successfully used to treat MDS and improve survival rates. However, hematopoietic stem cell transplantation (HSCT) remains the only curative treatment for MDS patients, effectively increasing patient survival and quality of life. Nevertheless, treatment-related toxicity, graft-versus-host disease, infectious complications, and relapse are still major post-transplant issues. In this review, through a retrospective analysis of past and present HSCT for the treatment of MDS, we provide insights for the future.

Pulmonary infection associated with immune dysfunction is associated with poor prognosis in patients with myelodysplastic syndrome accompanied by TP53 abnormalities

The aim of this study was to examine the characteristics and prognosis of patients with myelodysplastic syndrome (MDS) accompanied by TP53 abnormalities and explore potential prognostic factors and treatment responses. This retrospective analysis included 95 patients with MDS and TP53 abnormalities and 173 patients with MDS without TP53 abnormalities at the Fujian Medical University Union Hospital between January 2016 and June 2023. Among patients with TP53 abnormalities, 26 (27.4%) developed AML during the disease course, with a median transformation time of 5.7 months. Complex karyotypes were observed in 73.1% of patients, and the proportions of -5 or del(5q), -7 or del(7q), +8, and -20 or del(20q) were 81.8%, 54.5%, 30.7%, and 25.0%, respectively. These patients exhibited poor survival, with a median overall survival (OS) of 7.3 months, and had 1- and 2-year OS rates of 42.2% and 21.5%, respectively. The complete response rates for azacitidine monotherapy, venetoclax combined with azacitidine, decitabine monotherapy, and decitabine combined with low-dose chemotherapy were 9.1%, 41.7%, 37.5%, and 33.3%, respectively. Long-term survival was similar among the four treatment groups. Patients who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) had a median OS of 21.3 months, which trended to be longer than that of patients who did not undergo allo-HSCT (5.6 months; P = 0.1449). Patients with pulmonary infection at diagnosis experienced worse OS than those without pulmonary infection (2.3 months vs. 15.4 months; P < 0.0001). Moreover, 61.9% of patients with pulmonary infection had immune dysfunction, with a ratio of CD4+ to CD8+ T lymphocytes below two. Pulmonary infections and complex karyotypes were independent adverse prognostic factors for OS. In conclusion, TP53 abnormalities in patients with MDS were frequently accompanied by complex karyotypes, and treatments based on hypomethylating agents or venetoclax have limited efficacy. Pulmonary infections associated with immune dysfunction is associated with poor prognosis.

TP53-Mutated Myelodysplasia and Acute Myeloid Leukemia

TP53-mutated myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) form a distinct and heterogeneous group of myeloid malignancies associated with poor outcomes. Studies carried out in the last years have in part elucidated the complex role played by TP53 mutations in the pathogenesis of these myeloid disorders and in the mechanisms of drug resistance. A consistent number of studies has shown that some molecular parameters, such as the presence of a single or multiple TP53 mutations, the presence of concomitant TP53 deletions, the association with co-occurring mutations, the clonal size of TP53 mutations, the involvement of a single (monoallelic) or of both TP53 alleles (biallelic) and the cytogenetic architecture of concomitant chromosome abnormalities are major determinants of outcomes of patients. The limited response of these patients to standard treatments, including induction chemotherapy, hypomethylating agents and venetoclax-based therapies and the discovery of an immune dysregulation have induced a shift to new emerging therapies, some of which being associated with promising efficacy. The main aim of these novel immune and nonimmune strategies consists in improving survival and in increasing the number of TP53-mutated MDS/AML patients in remission amenable to allogeneic stem cell transplantation.