Effects of ferroptosis-related gene HSPB1 on acute myeloid leukemia.

INTRODUCTION: The purpose of this study was to investigate the effects and potential mechanisms of ferroptosis-related gene heat shock protein beta-1 (HSPB1) on acute myeloid leukemia (AML). METHODS: The RNA-seq and clinical data of AML samples were obtained from the Genomic Data Commons database, and the FerrDb database was used to screen the marker, drive and suppressor of ferroptosis. Besides, DESeq2 was applied for differential expression analysis on AML samples and screening for differentially expressed genes (DEGs). The screened DEGs were subjected to the intersection analysis with ferroptosis-related genes to identify the ferroptosis-related DEGs. Next, the functional pathways of ferroptosis-related DEGs were further be discussed by Gene Ontology as well as Kyoto Encyclopedia of Genes and Genomes enrichment analysis of DEGs. Additionally, lasso regression analysis was employed to determine the differential genes related to prognosis in patients with AML and the survival analysis was performed. Subsequently, quantitative real-time polymerase chain reaction and western blot assay were applied to detect the mRNA and protein expression levels of HSPB1 in normal/AML bone marrow tissues and human normal (HS-5)/AML (HL-60) bone marrow cells, respectively. Furthermore, HSPB1 was knocked down to assess the expression changes of glutathione peroxidase 4 and acyl-CoA synthetase long-chain family member 4. Ultimately, the viability and oxidative stress levels of HL-60 were analyzed by Cell Counting Kit-8 and biochemical detection. RESULTS: A total of 4986 DEGs were identified in AML samples, with 3324 up-regulated and 1662 down-regulated. The enrichment analysis illustrated that ferroptosis-related DEGs were significantly enriched in response to metal irons, oxidative stress, and other pathways. After lasso regression analysis, 17 feature genes related to the prognosis of patients with AML were obtained, with HSPB1 exhibiting a significant correlation. The reliability of our models was verified by Cox regression analysis and survival analysis of the hazard model. Furthermore, the outcomes of quantitative real-time polymerase chain reaction and western blot showed that mRNA and protein expression levels of HSPB1 were significantly increased in the AML Group and HL-60 cells. The knockdown of HSPB1 in HL-60 cells reduced the protein level of glutathione peroxidase 4, increased the protein level of acyl-CoA synthetase long-chain family member 4, decreased the cell viability, and aggravated oxidative stress. CONCLUSION: Ferroptosis-related gene HSPB1 is highly expressed in patients with AML. In addition, HSPB1 may be involved in the occurrence and development of AML by regulating oxidative stress and ferroptosis-related pathways. This study provides new clues for further understanding of AML molecular mechanisms. Also, HSPB1 is expected to be a potential therapeutic target for AML in the future.

[Effect of Polyvinyl Alcohol/Graphene Oxide Aerogel on the Biological Characteristics of Acute Leukemia Cell Lines].

OBJECTIVE: To investigate the effects of polyvinyl alcohol (PVA) + graphene oxide (GO, weight content 1 wt%) aerogel three-dimensional (3D) scaffolds culture system on the proliferation, phenotype and drug resistance of ALL cell line Jurkat and AML cell line HL-60. METHODS: Jurkat cells and HL-60 cells were seeded in PVA+GO aerogel scaffolds for culture, and the structure of cells were observed by the scanning electron microscopy. Cell proliferation activity was measured by Cell Counting Kit-8 (CCK-8), cell phenotypes were analyzed by flow cytometry after fluorescent staining, then were compared with 2D cultured cells. Ara-C was used in drug resistance experiment, and CCK8 was used to detected cell proliferation activity. RESULTS: The proliferation activity of Jurkat cells grown in aerogel scaffolds was higher than that by 2D cultured in long-term culture. However, in HL-60 cells, the proliferation activity on 3D scaffold only at the 8th to 20th day was higher than that on the traditional 2D culture. Expression of CD4 in Jurkat cells increased after culture for 30 days, but the cell phenotypes in the 3D aerogel scaffolds were similar to 2D cultured cells. Phenotype of HL-60 cells was certainly changed after culture for 30 days, the cells can be divided into CD13+CD14-CD45+HLA-DR+,CD13-CD14--CD45+HLA-DR+ and CD13-CD14-CD45+HLA-DR- groups, and a new CD13+CD14-CD45-HLA-DR+ group of cells appeared in the cells cultured in 3D scaffolds, but not in 2D cultured cells. Drug resistance experiments showed that Jurkat cells in aerogel scaffolds have stronger drug resistance than those in 2D culture. CONCLUSION: PVA+GO (1 wt%) aerogel scaffolds can improve the proliferation and drug resistance of leukemia cells, and the phenotypes were the same as those in 2D culture, which can be used for cell amplification and biology characteristics studies and drug experiments. However, cell phenotypes should be analyzed before culture, and the effects of phenotypes changes on drug resistance should be eliminated.

[Ratio of Primary Bone Marrow Cells after Induction Chemothrapy for Two Weeks in the Patients with Ph- ALL and Its Influence on Complete Remission and Overall Progrosis].

OBJECTIVE: To investigate the influence of bone marrow blasts ratio after induction chemotherapy for 2 weeks in patients with Ph- ALL, and it's influence on complete remission (CR) and overall prognosis. METHODS: A total of 172 patients with Ph- ALL in our hospital from March 2012 to February 2016 were selected. The bone marrow blast ratio was analyzed by the receiver-operating characteristic curve (ROC) in patients after induction chemotherapy for 2 weeks, at same time its influence on CR and overall prognosis of Ph- ALL patients was evaluated. RESULTS: The cutoff value of CR was 0.075, its area under ROC was 0.763; the comparison of area under ROC with Az=0.5 showed statistically significant difference, therefore 172 patients with Ph- ALL were grouped according to bone marrow blast ratio after induction chemotherapy for 2 weeks: 104 cases (60.5%) with bone marrow blast ratio <0.075, 68 cases (39.5%) with bone marrow blast ratio ≥0.075. The Ph- ALL patinets with bone marrow blast ratio <0.075 who achieved CR and finally achieved CR after induction chemotherapy for 4 weeks acconnted for 89 (85.6%) and 99(95.2%) respectively, which were significantly higher than those in Ph- ALL patients with bone marrow blast ratio≥0.075, [29(42.6%) and 52 (76.5%)](P<0.05). In addition, the influencing factor clinically reducing the OS and DFS rate of patients and enhancing the ralapse rate of patients were mainly chemotherapy, the failure of induction chemotherapy (patients did not achieve CR after induction therapy for 4 weeks), the bone marrow blast ratio≥0.075 after induction treatment for 2 weeks, and CNSL at diagnosis and so on, while the enhaced WBC count at diagnosis was poor factor affecting the DFS rate of patients. CONCLUSION: After induction chemotherapy for 2 weeks, the elevated bone marrow blast ratio in Ph- ALL patients will be infavourable to CR, and the overall prognosis is poor.