The CDK4/6 Inhibitor Palbociclib Synergizes with ATRA to Induce Differentiation in AML.

Differentiation therapy based on ATRA almost cured acute promyelocytic leukemia (APL). However, it is disappointing that ATRA is not effective against other acute myeloid leukemia (AML) subtypes. Developing new and effective anti-AML therapies that promote leukemia differentiation is necessary. The CDK4/6-cyclin D pathway is a key initiator of the G1-S phase transition, which determines cell fate. Herein, we investigated whether the CDK4/6 inhibitor palbociclib would synergize with ATRA to promote leukemia differentiation in vitro and in vivo. Our findings revealed that CDK4/6-cyclin D pathway genes were aberrantly expressed in AML, and we observed that palbociclib sensitized AML cells to ATRA-induced morphologic, biochemical, and functional changes indicative of myeloid differentiation. The combination of palbociclib and ATRA attenuated AML cell expansion in vivo. These enhanced differentiation effects may be associated with the regulation of transcription factors, including RARα, E2F1, and STAT1. Overall, our findings demonstrate that CDK4/6 inhibition sensitizes AML cells to ATRA and could guide the development of novel therapeutic strategies for patients with AML.

Platelet is an unfavorable prognostic biomarker and associated with leukemia stem cells and immunomodulatory factors in acute myeloid leukemia.

Many clinical features, besides cytogenetic and molecular abnormalities, can affect the prognosis of the patients with acute myeloid leukemia (AML). Within this context it remains unclear if and how platelet counts affect the outcome of AML patients. In the present study, we examined the platelet counts at diagnosis in 633 newly diagnosed adult patients with AML from January 2010 to April 2021, and divided the cases into the group with low level of platelet counts (≤30×109/L, n=316) and high level of platelet counts (>30×109/L, n=317) according to the median platelet counts. We then validated the prognostic significance and potential mechanism of platelet counts on the relevance of spectral features for diagnostic risk stratification, initial induction therapy response, treatment effect maintenance, long-term survival, leukemia stem cells (LSCs) proportion, immunomodulatory cytokines level and immune cell subsets proportion. The results suggested that AML patients with a high level of platelet counts at diagnosis were associated with a high-risk molecular cytogenetic stratification, low complete remission (CR) rate, poor leukemia free survival (LFS), high proportion of LSCs, high level of transforming growth factor-ß (TGF-ß) and interleukin-1ß (IL-1ß), high proportion of regulatory T cells (Tregs) and monocytic myeloid-derived suppressor cells (M-MDSCs). It was demonstrated that platelet might be an unfavorable prognostic biomarker and was associated with LSCs and immunomodulatory cytokines as well as immune cell subsets in AML.

Prognostic value of the WT-1 gene combined with recurrent cytogenetic genes in acute myeloid leukemia.

Wilms tumor gene 1 (WT-1 gene) is overexpressed in most patients with acute myeloid leukemia (AML) and is an indicator for minimal residual disease (MRD) monitoring, but because the WT-1 gene has relatively low specificity, further studies of the prognostic value of a combination of the WT-1 and other genes are needed. The aim of this study was to explore the prognostic value of the WT-1 gene combined with recurrent cytogenetic genes in AML. In AML, the transcript expression of the WT-1 gene was closely related to leukemic tumor burden and acted as an accurate molecular indicator for MRD detection. Most patients with low expression levels of the WT-1 gene after induction and consolidation therapy were significantly associated with favorable relapse-free survival (RFS) and overall survival (OS), but 17.6% of patients relapsed and died of primary disease. However, when analyzing the WT-1 gene combined with recurrent cytogenetic genes, none of the patients with low expression levels of the WT-1 gene and recurrent cytogenetic genes negative relapsed and died in the median follow-up time of 19 months (range: 3-94 months). Thus, the combination of the WT-1 gene and recurrent cytogenetic genes is a more accurate indicator for MRD monitoring and prognosis evaluation in AML patients.

Monocytic Myeloid-Derived Suppressor Cells But Not Monocytes Predict Poor Prognosis of Acute Myeloid Leukemia

Objective: Some reports suggest that high absolute monocyte count (AMC) at diagnosis is an independent predictor of poor prognosis in acute myeloid leukemia (AML), but others disagree. Monocytic myeloid-derived suppressor cells (Mo-MDSCs) are immature monocytes. This study aimed to compare the value of monocytes and Mo-MDSCs in predicting the prognosis of AML. Materials and Methods: Peripheral blood samples from 107 newly diagnosed patients with AML and 47 healthy controls (HCs) were collected. We validated the clinical significance of AMC, monocyte count (CD14+CD45++), and Mo-MDSC count (CD14+HLA-DRlow/-CD45++) for initial induction therapy response, maintenance of treatment effects, and long-term survival. Results: Compared with HCs, the levels of AMC, monocyte count, and Mo-MDSC count were all significantly higher among patients with AML. However, only elevated Mo-MDSC count was significantly associated with lower complete remission rate, higher relapse/refractory rate, and poorer long-term survival. Conclusion: Mo-MDSCs but not monocytes predict the poor prognosis of AML.

Comparison of first-line treatments for elderly patients with diffuse large B-cell lymphoma: A systematic review and network meta-analysis.

Background: The incidence of DLBCL in elderly patients has been gradually increased. Considering their comorbidities and performance status, the first-line standard treatment hasn't been determined for the elderly. Methods: We performed a systemic review and network meta-analysis to compare the efficacy and safety of all eligible regimens as first line treatment for elderly patients with DLBCL. We searched PubMed, Cochrane Library, and Embase Library proceedings up to March 2022. Results: Our search yielded thirteen trials including 1839 patients. R2CHOP21 showed the best PFS with a statistical difference and the most favorable OS without a statistical difference. RCOMP showed the most clinical benefits in EFS, CR and OR with no significant difference. The point estimate was in favored improved DFS with RCHOP14 than RCHOP21, although this was not statistically significant. In a subgroup analysis concerning 3-4 grade AEs revealed R-COMP was associated with a decrease in grade III/IV neutropenia and cardiac toxic events; RminiCEOP was associated with the lower rates of 3-4 grade anemia, thrombocytopenia and infection; RCHOP21 had the lowest rate of 3-4 grade AE of neurotoxicity. Conclusion: The findings of our meta-analysis indicated that R2CHOP21 provided the best disease control in PFS and represented an optimal first-line treatment option in the elderly with DLBCL. Furthermore, RCOMP, RminiCEOP and RCHOP21 exhibited lower rates in different 3-4 grade AEs and might be reasonable treatment options in the elderly with poor general conditions.