Akute Leukämien des Erwachsenen

Histone lysine demethylase KDM5B facilitates proliferation and suppresses apoptosis in human acute myeloid leukemia cells through the miR-140-3p/BCL2 axis

The histone lysine demethylase KDM5B is frequently up-regulated in various human cancer cells. However, its expression and functional role in human acute myeloid leukemia (AML) cells remain unclear. Here, we found that the expression level of KDM5B is high in primary human AML cells. We have demonstrated that knocking down KDM5B leads to apoptosis and impairs proliferation in primary human AML and some human AML cell lines. We further identified miR-140-3p as a downstream target gene of KDM5B. KDM5B expression was inversely correlated with the miR-140-3p level in primary human AML cells. Molecular studies showed that silencing KDM5B enhanced H3K4 trimethylation (H3K4me3) at the promoter of miR-140-3p, leading to high expression of miR-140-3p, which in turn inhibited B-cell CLL/lymphoma 2 (BCL2) expression. Finally, we demonstrate that the defective proliferation induced by KDM5B knockdown (KD) can be rescued with the miR-140-3p inhibitor or enhanced by combining KDM5B KD with a BCL2 inhibitor. Altogether, our data support the conclusion that KDM5B promotes tumorigenesis in human AML cells through the miR-140-3p/BCL2 axis. Targeting the KDM5B/miR-140-3p/BCL2 pathway may hold therapeutic promise for treating human AML.

Decision-making trade-offs: A classic grounded theory study of Chinese acute leukaemia patients and their family caregivers across the trajectory of illness

AIM AND OBJECTIVES

To identify the main concern of patients with acute leukaemia and their family caregivers in the process of coping with the disease and to determine how patients and their family caregivers address these concerns on an ongoing basis.

BACKGROUND

Acute leukaemia is a progressive disease that may lead to physical problems and mental stress in patients. It also affects the psychological well-being and quality of life of family caregivers. Nevertheless, few studies explore the behavioural pattern across the trajectories of illness in Chinese patients with acute leukaemia and their family caregivers.

DESIGN

Grounded theory.

METHODS

Theoretical sampling was performed to collect 14 sets of secondary data from Bilibili platform, literature, articles from WeChat official account, press releases and documentary. A total of 29 participants were selected to participate in semistructured interviews from the haematology department of a tertiary care hospital in Fuzhou, Fujian Province from January 2021 to November 2021. Data collection and analysis were conducted in a synchronous iterative manner until theoretical saturation was reached. Data analysis included open coding, selective coding and constant comparison, et al. The CCOREQ checklist was utilised.

RESULTS

This study discovered the main concern (i.e. seeking survival) and main behavioural pattern of how patients with acute leukaemia and their family caregivers addressed this issue. Three decision-making strategies, 'responding' 'accommodating' and 'resisting' also emerged.

CONCLUSIONS

This study explored the behavioural pattern of patients with acute leukaemia and their family caregivers in the process of coping with disease. The study found that the main concern of patients with acute leukaemia and their family caregivers, and provided a theoretical basis for disease management and nursing interventions for them in the future.

RELEVANCE TO CLINICAL PRACTICE

The findings of this study contribute to nursing knowledge, practice in the field of patients' participation in decision-making.

PATIENT OR PUBLIC CONTRIBUTION

Due to the characteristics of grounded theory (no presupposition of research questions), the interviews in this study mainly focus on theory generation. Participants were not asked to assess the burden of the intervention and the time required to participate in the study, as interviews were conducted for theory generation. This study may assist patients and family caregivers in obtaining better understand and adapt to changes across the trajectory of illness, as well as to promote public destigmatisation of acute leukaemia and reforms in family-hospital-community diversified care.

Genetic features and efficacy of decitabine-based chemotherapy in elderly patients with acute myeloid leukemia

OBJECTIVES

The outcome of elderly acute myeloid leukemia (AML) patients is poor, which was traditionally attributed to patient- and leukemia-related factors. However, studies about the genetic features of these elderly patients have not been integrated and the genetic mechanism of their poor outcome is less known.

METHODS

Here, we used next generation sequencing (NGS) to identify the genetic features of elderly AML patients and confirmed the efficacy of chemotherapy based on molecular aberrations. Mutations in 111 genes relevant to hematological malignancy was analysed by virtue of NGS and the genetic differences were compared between elderly (n=52) and young (n=161) AML patients. Furthermore, the outcome of decitabine-based chemotherapy was identified in elderly patients.

RESULTS

Frequencies of adverse genetic alterations, such as RUNX1 and secondary-type mutations (ASXL1, STAG2 and spliceosome), were much higher in elderly patients, while the frequency of WT1 mutations was much lower. Moreover, epigenetic mutations such as DNMT3A, TET2, ASXL1 and IDH2, were also more common in elderly patients. Furthermore, there were 39 elderly patients receiving the decitabine-based chemotherapy, and the results showed that the overall response rate (ORR) and complete remission rate (CR) were 76.9% and 71.8%, respectively. The median overall survival (OS) for those older patients was 12 months, and the 2-year OS probability was 20.5%.

DISCUSSION

Our study provides deep understanding into the molecular mechanisms of the poor outcome of elderly AML patients.

CONCLUSION

Epigenetic mutations play an important role, and decitabine-based regimen can be used as alternative first-line chemotherapy for elderly patients.

Low-dose decitabine enhances chidamide-induced apoptosis in adult acute lymphoblast leukemia, especially for p16-deleted patients through DNA damage

AIM

To investigate the combined action of decitabine (DAC) with chidamide (CS055) on acute lymphoblastic leukemia (ALL) cells.

MATERIALS & METHODS

ALL cell lines as well as primary cells from 17 ALL patients were subjected to different treatments and thereafter cell counting Kit-8 (CCK-8) assay, flow cytometry and western blot were employed to determine IC₅₀, apoptosis and checkpoint kinase 1 and γH2A.X expression.

RESULTS

Low-dose DAC combined with CS055 could effectively kill ALL cells by the reduction of cell viability and induction of apoptosis. This was also observed in primary cells from 17 ALL patients, especially for those with p16 gene deletion. Suppression of checkpoint kinase 1 phosphorylation and upregulation of γH2A.X expression was demonstrated to participate in DAC plus CS055-induced apoptosis.

CONCLUSION

Low-dose DAC could enhance chidamide-induced apoptosis in adult ALL, especially for patients with p16 gene deletion through DNA damage.