DNA damage to bone marrow stromal cells by antileukemia drugs induces chemoresistance in acute myeloid leukemia via paracrine FGF10-FGFR2 signaling.

Chemoresistance remains a major challenge in the current treatment of acute myeloid leukemia (AML). The bone marrow microenvironment (BMM) plays a complex role in protecting leukemia cells from chemotherapeutics, and the mechanisms involved are not fully understood. Antileukemia drugs kill AML cells directly but also damage the BMM. Here, we determined antileukemia drugs induce DNA damage in bone marrow stromal cells (BMSCs), resulting in resistance of AML cell lines to adriamycin and idarubicin killing. Damaged BMSCs induced an inflammatory microenvironment through NF-κB; suppressing NF-κB with small molecule inhibitor Bay11-7082 attenuated the prosurvival effects of BMSCs on AML cell lines. Furthermore, we used an ex vivo functional screen of 507 chemokines and cytokines to identify 44 proteins secreted from damaged BMSCs. Fibroblast growth factor-10 (FGF10) was most strongly associated with chemoresistance in AML cell lines. Additionally, expression of FGF10 and its receptors, FGFR1 and FGFR2, was increased in AML patients after chemotherapy. FGFR1 and FGFR2 were also widely expressed by AML cell lines. FGF10-induced FGFR2 activation in AML cell lines operates by increasing P38 MAPK, AKT, ERK1/2, and STAT3 phosphorylation. FGFR2 inhibition with small molecules or gene silencing of FGFR2 inhibited proliferation and reverses drug resistance of AML cells by inhibiting P38 MAPK, AKT, and ERK1/2 signaling pathways. Finally, release of FGF10 was mediated by ß-catenin signaling in damaged BMSCs. Our data indicate FGF10-FGFR2 signaling acts as an effector of damaged BMSC-mediated chemoresistance in AML cells, and FGFR2 inhibition can reverse stromal protection and AML cell chemoresistance in the BMM.

Clinical and prognostic profile of SRSF2 and related spliceosome mutations in patients with acute myeloid leukemia.

BACKGROUND: Mutations in splicing factor (SF) genes are frequently detected in myelodysplastic syndrome, but their clinical and prognostic relevance in acute myeloid leukemia (AML) have rarely been reported. METHODS: A total of 368 newly diagnosed non-M3 AML patients were included in this study. Next generation sequencing including four SF genes was performed on the genomicDNA. The clinical features and survival were analyzed using statistical analysis. RESULTS: We found that 64 of 368 patients harbored SF mutations. The SF mutations were much more frequently found in older or male patients. SRSF2 mutations were shown obviously co-existed with IDH2 mutation. The level of measurable residual disease after first chemotherapy was higher in SF-mutated patients compared to that in SF-wild patients, while the complete remission rate was significantly decreased. And the overall survival of SF-mutated patients was shorter than that of SF-wild patients. Moreover, our multivariable analysis suggests that the index of male, Kit mutation or ZRSR2 mutation was the independent risk factor for overall survival. SRSF2mut was associated with older age, higher proportion of peripheral blasts or abnormal cell proportion by flow cytometry. CONCLUSION: SF mutation is a distinct subgroup of AML frequently associated with clinic-biological features and poor outcome. SRSF2mut could be potential targets for novel treatment in AML.

Subclones of bone marrow CD34+ cells in acute myeloid leukemia at diagnosis confer responses of patients to induction chemotherapy.

BACKGROUND: Acute myeloid leukemia (AML) is a hematopoietic malignancy with a prognosis that varies with genetic heterogeneity of hematopoietic stem/progenitor cells (HSPCs). Induction chemotherapy with cytarabine and anthracycline has been the standard care for newly diagnosed AML, but about 30% of patients have no response to this regimen. The resistance mechanisms require deeper understanding. METHODS: In our study, using single-cell RNA sequencing, we analyzed the heterogeneity of bone marrow CD34+ cells from newly diagnosed patients with AML who were then divided into sensitive and resistant groups according to their responses to induction chemotherapy with cytarabine and anthracycline. We verified our findings by TCGA database, GEO datasets, and multiparameter flow cytometry. RESULTS: We established a landscape for AML CD34+ cells and identified HSPC types based on the lineage signature genes. Interestingly, we found a cell population with CRIP1high LGALS1high S100Ashigh showing features of granulocyte-monocyte progenitors was associated with poor prognosis of AML. And two cell populations marked by CD34+ CD52+ or CD34+ CD74+ DAP12+ were related to good response to induction therapy, showing characteristics of hematopoietic stem cells. CONCLUSION: Our study indicates the subclones of CD34+ cells confers for outcomes of AML and provides biomarkers to predict the response of patients with AML to induction chemotherapy.

Role of CDH23 as a prognostic biomarker and its relationship with immune infiltration in acute myeloid leukemia.

BACKGROUND: Cadherin-23 (CDH23) plays an important role in intercellular adhesion and is involved in the progression of several types of cancer. However, the biological functions and effect of CDH23 expression on the prognosis of patients with acute myeloid leukemia (AML) are unexplored. Herein, we aim to characterize the role and molecular functions of CDH23 in AML. METHODS: We downloaded the transcriptomic profiles and clinical data from the Cancer Genome Atlas and Beat AML trial. The expression level of CDH23 was assessed using Gene Expression Profiling Interactive Analysis (GEPIA). Kaplan-Meier survival analysis was used to assess prognostic value of CDH23. Correlation and biological function analyses were performed using LinkedOmics and GeneMANIA. Relationship of CDH23 with immune infiltration level was determined using Tumor Immune Estimation Resource (TIMER). RESULTS: We found that the CDH23 expression was aberrantly upregulated in patients with AML and could be used as an independent risk factor of overall survival using Cox multivariate analysis. Notably, we observed a negative correlation between CDH23 expression and immune cell infiltration abundance by calculating the immune and stromal scores. In addition, functional enrichment analysis established that CDH23 plays a crucial role in tumor immunity. CONCLUSIONS: Our findings indicate that upregulated CDH23 expression corresponds to decreased overall survival of patients with AML. CDH23 may be involved in mediating tumor immune environment, and this highlights the potential of CDH23 as a therapeutic target in AML.

hsa_circ_0000745 promotes cervical cancer by increasing cell proliferation, migration, and invasion.

Circular RNAs (circRNAs) participate in gene regulation and malignant tumor progression, including uterine cervical cancer (CC). In this study, the expression profile of circRNAs in CC was detected using circRNA microarrays. Then, we selected hsa_circ_0000745 for further examination from the significantly dysregulated circRNAs. Proliferation assays, Transwell assays, quantitative reverse transcription polymerase chain reaction, western blot analysis and tumorigenesis tests in vivo were used to validate the role of hsa_circ_0000745 in CC. hsa_circ_0000745 was upregulated in CC, and its level positively correlated with the level of its linear messenger RNA isoform. Patients with poorly differentiated tumors or vascular/lymphatic invasion presented higher expression of hsa_circ_0000745. The role of hsa_circ_0000745 was illuminated by knocking down hsa_circ_0000745 in CC cells, and the results revealed that reducing hsa_circ_0000745 inhibited cell proliferation, migration, and invasion in CC by upregulating E-cadherin (E-cad) expression. In summary, as a tumor promoter in CC, hsa_circ_0000745 enhances the cell's ability to proliferate, migrate, and invade by reducing the expression of E-cad. hsa_circ_0000745 is a candidate target for the treatment of CC in the clinic.

Genetic polymorphisms of IL-18 rs1946518 and IL-1ß rs16944 are associated with prognosis and survival of acute myeloid leukemia.

BACKGROUND: Though the pathogenesis of AML is still unknown, accumulating evidence revealed that immune response plays a vital part in it. NLRP3 inflammasome as a component of immune system has been found related to several cancers. The single nucleotide polymorphisms (SNPs) of NLRP3 inflammasome genes may be related to pathogenesis and prognosis of AML. METHODS AND RESULTS: We determined polymorphisms of NLRP3 (rs35829419), CARD8 (rs2043211), IL-1ß (rs16944), IL-18 (rs1946518) and NF-κB -94 ins/del ATTG in de novo AML patients to find out whether they play roles in the susceptibility and severity of AML. In our study, 383 AML cases and 300 randomly selected healthy individuals were examined for the polymorphisms and expression of NLRP3 genes. IL-1ß (rs16944) polymorphism in different risk AML subgroups was found statistically different, with more GA genotype in favorable-risk cytogenetics group. We also demonstrated that the bone marrow blasts of patients carrying IL-18 (rs1946518) GG or GT genotype were higher than patients of TT genotype. IL-18 plasma level of patients with IL-18 (rs1946518) GT or TT genotype was higher than GG genotype. Moreover, the GT genotype of IL-18 (rs1946518) led to statistically poorer AML-specific survival. CONCLUSION: IL-1ß (rs16944) and IL-18 (rs1946518) may be served as potential predictors for AML.

Characterization of hsa_circ_0004277 as a New Biomarker for Acute Myeloid Leukemia via Circular RNA Profile and Bioinformatics Analysis.

Circular RNAs (circRNAs) represent a widespread class of non-coding RNAs, which drew little attention in the past. Recently, limited data showed their promising future to act as biomarkers in human cancer, but the characteristics and functions remain largely unknown in hematopoietic malignancies, especially in leukemia. In this study, with the help of circRNA microarray, we demonstrated the expression profile of circRNAs in acute myeloid leukemia (AML) patients, and identified a large number of circRNAs possibly expressed in a leukemia specific manner. We also described a circRNA signature related to AML risk-status based on the bioinformatics prediction. In particular, a downregulated circRNA, hsa_circ_0004277, was characterized and functionally evaluated in a cohort of 115 human samples, thus offering a potential diagnostic marker and treatment target in AML. Interestingly, we found chemotherapy could significantly restore the expression of hsa_circ_0004277, indicating the increasing level of hsa_circ_0004277 was associated with successful treatment. Furthermore, a detailed circRNA-miRNA-mRNA interaction network was presented for hsa_circ_0004277, allowing us to better understand its underlying mechanisms for function in AML.

Role of stromal cells-mediated Notch-1 in the invasion of T-ALL cells.

Extra-medullary infiltration is still one of the main causes of recurrence and treatment failure of T-cell acute lymphoblastic leukemia (T-ALL). Intensive studies revealed that Notch pathway plays an important role in the invasion of tumor cells. Notch pathway can be triggered by binding of Notch receptors on T-ALL cells to their ligands on bone marrow stromal cells (BMSCs), which contributes to the development of T-ALL. However, the effect and molecular mechanisms of BMSCs in invasion of T-ALL cells remain unclear. To explore the effect of Notch-1 on the invasiveness of T-ALL cells, we co-cultured T-ALL cells with BMSCs (from healthy donors)/BMSCs(⁎) (from newly diagnosed T-ALL patients). The results demonstrated that BMSCs/BMSCs(⁎) promoted invasion of T-ALL cells through activating Notch-1 signaling. In particular, T-ALL cells showed a higher invasive potential in the presence of BMSCs(⁎) than BMSCs. Knockdown of Notch-1 prevented the positive effect of stromal cells-mediated invasion. Our study also showed that BMSCs/BMSCs(⁎)-induced Notch-1 activation increased the expression of matrix metalloprote inase-2 (MMP-2) and matrix metalloprote inase-9 (MMP-9), which increased invasiveness. These results provided theoretical and laboratory basis for the prevention and treatment of extra-medullary infiltration of T-ALL cells.

Inactivation of Notch signaling reverses the Th17/Treg imbalance in cells from patients with immune thrombocytopenia.

T helper 17 (Th17) cells and regulatory T (Treg) cells, along with Th1 and Th2 cells, may contribute to the development of immune thrombocytopenia (ITP). The imbalance of Th17/Treg toward Th17 cells has been shown to play a pivotal role in the peripheral immune response. Notch signaling has been implicated in peripheral T-cell activation and effector cell differentiation. However, the role of Th17/Treg in the pathogenesis of ITP and the effect of Notch signaling on Th17/Treg imbalances remain largely elusive in ITP. In vitro, we treated peripheral blood mononuclear cells (PBMCs) from ITP and healthy controls with γ-secretase inhibitor (DAPT). Th17 cells and Treg cells were measured by flow cytometry and IL-17, IL-21, and IL-10 secretion by enzyme immunoassay technique. The mRNA expression of Ntoch1, Hes1, Hey1, RORγt, and Foxp3 was investigated by RT-PCR. Cell proliferation and apoptosis were determined by the Cell Counting Kit-8 and apoptosis detection kit. We demonstrated that DAPT was effective in inhibiting mRNA expression of Notch signaling molecules. In untreated cultured PBMCs from ITP patients, we observed elevated Th17 cell and IL-21 levels and RORγt mRNA expression, decreased Treg cells and Foxp3 mRNA expression, and an increased ratio of Th17/Treg and RORγt/Foxp3. After inactivating Notch signal by DAPT, Th17 cells and Th17/Treg ratio were dose dependently decreased and accompanied by the reduction of IL-17 in culture supernatants and RORγt mRNA expression in ITP patients. However, no significant difference was found for Treg cells and Foxp3 mRNA expression, RORγt/Foxp3 ratio, and IL-21 and IL-10 levels after DAPT treatment in ITP patients. We also present evidence that the effect of DAPT inhibition on the Th17 cell response was associated with downregulation of RORγt and IL-17 transcription using human in vitro polarization. In conclusion, our findings highlight the importance of Notch signaling in Th17/Treg imbalances in ITP. Inactivation of Notch signaling might be a potential immunoregulatory strategy in ITP patients.

The existence of Th22, pure Th17 and Th1 cells in CIN and Cervical Cancer along with their frequency variation in different stages of cervical cancer.

BACKGROUND: Recently, it is found that T-helper (Th) 22 cells are involved in different types of autoimmune and tumor diseases. But, till now, no study has been carried out to understand the involvement of these cells in cervical cancer (CC). METHODS: Flow cytometry was used to determine the expression of interferon gamma (IFN-γ), Interleukin-22 (IL-22), IL-17 in the peripheral blood of healthy controls (HC), CIN and cervical cancer patients. From peripheral blood mononuclear cells (PBMCs), mRNA expression levels of Aryl hydrocarbon receptor (AHR), RAR-related orphan receptor C (RORC), TNF-α and IL-6 were respectively determined. Using the method of ELISA, plasma concentrations of IL-22, IL-17 and TNF-α were examined. RESULTS: Th22 and Th17 cells were elevated in CC and CIN patients. Th1 cells and the plasma concentrations of IL-22 in CC patients were significantly increased compared with HC. In CC patients, an increased prevalence of Th22 cells was associated with lymph node metastases. There was a positive correlation between Th22 and Th17 cells, but an approximately negative correlation between Th22 and Th1 cells in CC patients. The mRNA expression of RORC, TNF-α and IL-6 was significantly high in CC patients. CONCLUSIONS: Our results indicate that there is a higher circulatory frequency of Th22, Th17 and Th1 cells in CC which may conjointly participate in the pathogenesis and growth of CC.

Genistein exhibits anti-cancer effects via down-regulating FoxM1 in H446 small-cell lung cancer cells.

Genistein, a major isoflavone constituent in soybeans, has been reported to exhibit multiple anti-tumor effects, such as inducing cell cycle arrest, triggering apoptosis, and inactivating critical signaling pathways in a few human cancer cells. Here, we investigated the anti-tumor effects of genistein on the small-cell lung cancer (SCLC) cell line H446 and the underlying molecular mechanisms. H446 cells were treated with various concentrations of genistein, and experiments including CCK-8 assay, colony formation assay, flow cytometry analysis, wound healing assay, real-time polymerase chain reaction (PCR), western blot analysis, and plasmid transfection were used to investigate the influence of genistein on cell proliferation, migration ability, apoptosis, cell cycle progression, as well as the mRNA and protein alterations of FoxM1 pathway molecules. We found that genistein significantly inhibited the proliferation and migration ability of H446 cell, accompanied by apoptosis and G2/M phase cell cycle arrest. In addition, genistein enhanced the anti-proliferative effect of cisplatin on H446 cells. Importantly, genistein led to attenuation of the FoxM1 protein and down-regulated a series of FoxM1 target genes regulating cell cycle and apoptosis including Cdc25B, cyclin B1, and survivin. In addition, up-regulation of FoxM1 by cDNA transfection prior to genistein treatment could reduce genistein-induced H446 proliferation inhibition. Thus, for the first time, we demonstrated that genistein exerted multiple anti-tumor effects in H446 SCLC cell line at least partly mediated by the down-regulation of FoxM1. FoxM1 has the potential as a novel therapeutic agent in SCLC and is worthy of further study.

Wnt signaling is involved in 6-benzylthioinosine-induced AML cell differentiation.

BACKGROUND: We previously demonstrated that 6-benzylthioinosine (6-BT) could induce the differentiation of a subset of acute myeloid leukemia (AML) cell lines and primary AML cells regardless of their cytogenetics. In this study we investigated whether Wnt signaling pathways played roles in 6-BT-induced differentiation of AML cells. METHODS: We induced differentiation of HL-60 leukemic cells and primary AML cells in vitro using 6-BT. Real-time PCR (qPCR), western blot, and luciferase assays were used to examine the molecules' expression and biological activity in canonical and noncanonical Wnt signaling pathways. AML cell differentiation was measured by the Nitroblue tetrozolium (NBT) reduction assay. RESULTS: 6-BT regulated the expression of both canonical and non-canonical Wnt signaling molecules in HL-60 cells. Both 6-BT and all-trans-retinoic-acid (ATRA) reduced canonical Wnt signaling and activated noncanonical Wnt/Ca2+ signaling in HL-60 cells. Pre-treatment of HL-60 cells with an inhibitor of glycogen synthase kinase-3ß (GSK-3ß), which activated canonical Wnt signaling, partly abolished the differentiation of HL-60 cells induced by 6-BT. Pre-treatment of HL-60 cells with an inhibitor of protein kinase C (PKC), resulting in inactivation of non-canonical Wnt/Ca2+ signaling, abolished 6-BT-induced differentiation of HL-60 cells. Several molecules in the non-canonical Wnt/Ca2+ pathway were detected in bone marrow samples from AML patients, and the expression of FZD4, FZD5, Wnt5a and RHOU were significantly reduced in newly diagnosed AML samples compared with normal controls. CONCLUSIONS: Both canonical and non-canonical Wnt signaling were involved in 6-BT-induced differentiation of HL-60 cells, and played opposite roles in this process. Wnt signaling could be involved in the pathogenesis of AML not only by regulating self-renewal of hematopoietic stem cells, but also by playing a role in the differentiation of AML cells.

Changes of Th17/Tc17 and Th17/Treg cells in endometrial carcinoma.

OBJECTIVES: T helper 17 (Th17), T cytotoxic 17 (Tc17) and regulatory T (Treg) cells are important factors in the pathogenesis of inflammatory and autoimmune diseases. However, information concerning the roles of these cells in antitumor immunity or endometrial tumorigenesis remains limited. In this study, we aimed to describe the distribution of Th17, Tc17 and Treg cells in endometrial carcinoma patients, and elucidate the probable role of these effector T cells. METHODS: We assessed the expression of interleukin (IL)-17 and Foxp3 in the peripheral blood of endometrial carcinoma patients and healthy controls by flow cytometry to determine the relative numbers of Th17, Tc17 and Treg cells. Th17 cells and Tc17 cells were counted as percentages of the total number of CD3(+) T cells; Treg cells were counted as a percentage of the total number of CD4(+) T cells. We also evaluated Th17 and Tc17 cells in tumor tissue by immunohistochemical staining. IL-17 and IL-10, dominant products of these three cell types, were detected by using enzyme-linked immunosorbent assays. RESULTS: The frequencies of Th17, Tc17 and Treg cells, as well as the serum level of IL-10, were significantly elevated in endometrial carcinoma patients compared to healthy controls. The Th17/Tc17 and Th17/Treg ratios were also observed to change significantly. However, there was no significant difference on the IL-17 levels in the serum. Additionally, immunohistochemistry performed on tumor tissues indicated that the amounts of Th17 and Tc17 increased in the cancer patients. CONCLUSIONS: Our data suggests a probable involvement of Th17, Tc17 and Treg cells in the pathogenesis of endometrial carcinoma. Restoring the balance of these cells may help with the research and development of immunotherapies for endometrial carcinoma.

Bortezomib and IL-12 produce synergetic anti-multiple myeloma effects with reduced toxicity to natural killer cells.

The aim of this study was to examine the hypothesis that a combination of proteasome inhibition by bortezomib and immune therapy with interleukin-12 (IL-12) can produce enhanced antitumor efficacy relative to the effects of either of these agents alone. A mouse xenograft model of myeloma was developed. The mice were randomly divided into saline control (NS), IL-12 (0.4 µg/animal; intraperitoneal), bortezomib (0.75 mg/kg; intravenous), and bortezomib+IL-12 groups. Effects of treatments on tumor growth were assessed by before and after treatment comparisons and group comparisons. The effects of various treatments on the number of peripheral blood lymphocytes and natural killer (NK) cells were assessed by complete blood count and flow cytometry analysis. The cell-killing function of NK cells in splenocytes was evaluated using the lactate dehydrogenase release assay. IL-12 treatment alone produced a mild decrease in tumor volume compared with control (P>0.05). Bortezomib alone resulted in substantial inhibition of tumor growth at varying time points, reaching ~65 and ~60% reduction in tumor volume after 15 and 21 days of therapy, respectively. At the same time points, the combination therapy produced ~75 and ~84% decreases in tumor growth, respectively, which were significantly greater than the reduction produced by bortezomib monotherapy. Tumors resumed growth upon termination of bortezomib treatment at 2 weeks, although the tumor volume was still significantly smaller than that in the time-matched NS and IL-12 animals. This rebound of tumor growth was completely prevented with the combination therapy, and tumor volume continued to decrease throughout the time course. The percentage and total number of NK cells were significantly decreased after bortezomib monotherapy and combination therapy; however, they remained unaltered after IL-12 treatment compared with no treatment. Further, combination therapy significantly restored the bortezomib-induced functional impairment of the cell-killing capability of NK cells, relative to bortezomib alone. We conclude that the bortezomib-IL-12 combination therapy offers superior antitumor efficacy over monotherapy with either bortezomib or IL-12 in a mouse model of myeloma. Restoration of bortezomib-induced functional impairment of NK cells by IL-12 may be a mechanism for the synergetic effects of the two agents. Therefore, a combination of the two agents may represent a more rational therapeutic approach for myeloma.

SMG1 acts as a novel potential tumor suppressor with epigenetic inactivation in acute myeloid leukemia.

Suppressor with morphogenetic effect on genitalia family member (SMG1) belongs to a family of phosphoinositide 3-kinase-related kinases and is the main kinase involved in nonsense-mediated mRNA decay. Recently, SMG1 was suggested as a novel potential tumor suppressor gene, particularly in hypoxic tumors. To investigate the function of SMG1 in acute myeloid leukemia (AML), we performed methylation-specific polymerase chain reaction and found that SMG1 was hypermethylated in the promoter region. SMG1 hypermethylation was found in 66% (33/50) of AML samples compared with none (0/14) of the normal controls. SMG1 mRNA was down-regulated in AML patients with hypermethylation status whereas it was readily expressed in patients without methylation. Moreover, treatment of AML cells with demethylating agent 5-aza-2'-deoxycytidine (decitabine) inhibited AML cell growth and induced apoptosis by reversing SMG1 methylation status and restoring SMG1 expression. On the other hand, knockdown of SMG1 by RNA interference inhibited apoptosis. We also found that mTOR expression level was negatively correlated to SMG1 expression in AML patients which indicated that SMG1 and mTOR maybe act antagonistically to regulate AML cell growth. In conclusion, our results indicate that SMG1 acts as a potential tumor suppressor with epigenetic regulation in AML.

Elevated Th22 cells correlated with Th17 cells in peripheral blood of patients with acute myeloid leukemia.

Acute myeloid leukemia (AML) is a hematological tumor in which progress T helper (Th) subsets including Th22, Th17, and Th1 cells play a pivotal role. However, the role of T helper (Th) subsets in the immune pathogenesis of AML remains unclear. Here, we investigated frequencies of Th22, Th17, pure Th17, and Th1 cells in the peripheral blood (PB) of AML patients. We demonstrated that Th22, Th17, and pure Th17 in newly-diagnosed (ND) and non-complete remission (Non-CR) AML patients and plasma IL-22 in ND AML patients were significantly increased. Retinoid-related orphan receptor C (RORC) expression was significantly elevated in CR and Non-CR AML patients. However, Th1 in ND AML patients and IL-17 in ND, Non-CR or CR AML patients was significantly decreased compared with controls. Moreover, Th22 and IL-22 showed positive correlation with pure Th17, but Th22 showed negative correlation with Th1 in ND AML patients. RORC showed positive correlation with Th22 and approximately positive correlation with pure Th17 in Non-CR patients. PB blast cell showed positive correlation with Th22 and negative correlation with Th1 in ND AML patients. Our results indicate that Th22 and pure Th17 cells conjointly contribute to the pathogenesis of AML and might be promising novel clinical index for AML.

Analysis of gene mutation characteristics and its correlation with prognosis in patients with myelodysplastic syndromes.

Gene mutations are a pivotal component of the pathogenesis of MDS, and they hold profound prognostic significance for predicting treatment responses and survival outcomes. However, reports about mutation patterns in Chinese MDS patients are limited. In this study, we analyzed the genetic mutation of 23 genes in 231 patients with MDS using next-generation sequencing (NGS) technology, and explored the characteristics of gene mutations in MDS patients and their associations with clinical outcomes, survival, and transformation outcomes. Our results showed that 68.83% patients had at least one gene mutation, and the most common mutations were ASXL1 (21.65%), SF3B1 (17.32%), U2AF1 (16.02%), TET2 (14.72%) and TP53 (8.66%). We also showed that the genetic mutations of TP53, U2AF1 and DNMT3A are independent risk factors for death in patients with MDS, and the ETV6 gene mutation was an independent risk factor for the transformation of MDS patients to AML through the univariate and multivariate Cox regression analysis model. Additionally, the study developed a risk score based on gene mutation data that demonstrated robust predictive capability and stability for the overall survival of MDS patients. Our research provided a strong theoretical basis for the establishment of personalized treatment and prognostic risk assessment models for Chinese MDS patients.

Propionate promotes ferroptosis and apoptosis through mitophagy and ACSL4-mediated ferroptosis elicits anti-leukemia immunity.

Short-chain fatty acids (SCFAs), particularly propionate and butyrate, have been reported in many cancers. However, the relationship between propionate and acute myeloid leukemia (AML) remains unclear. Additionally, Acyl-CoA synthetase long chain family member 4 (ACSL4) has been reported to regulate immunity in solid tumors, but there are still many gaps to be filled in AML. Here, we discovered the underlying mechanism of propionate and ACSL4-mediated ferroptosis for immunotherapy. Our results showed that the level of propionate in the AML patients' feces was decreased, which was correlated to gut microbiota dysbiosis. Moreover, we demonstrated that propionate suppressed AML progression both in vivo and in vitro. In mechanism, propionate induced AML cells apoptosis and ferroptosis. The imbalance of reactive oxygen species (ROS) and redox homeostasis induced by propionate caused mitochondrial fission and mitophagy, which enhanced ferroptosis and apoptosis. Furthermore, ACSL4-mediated ferroptosis caused by propionate increased the immunogenicity of AML cells, induced the release of damage-associated molecular patterns (DAMPs), and promoted the maturation of dendritic cells (DCs). The increased level of immunogenicity due to ferroptosis enable propionate-based whole-cell vaccines to activate immunity, thus further facilitating effective killing of AML cells. Collectively, our study uncovers a crucial role for propionate suppresses AML progression by inducing ferroptosis and the potential mechanisms of ACSL4-mediated ferroptosis in the regulation of AML immunity.

circFAM193B interaction with PRMT6 regulates AML leukemia stem cells chemoresistance through altering the oxidative metabolism and lipid peroxidation.

Most forms of chemotherapy for acute myeloid leukemia (AML) are often ineffective in eliminating leukemic stem cells (LSCs), as their underlying mechanisms remain unclear. Here, we have identified circFAM193B, which regulates the redox biology of LSCs and is associated with unfavorable outcomes in AML patients. In vitro and in vivo assays suggested that circFAM193B significantly inhibits LSCs chemotherapy resistance and AML progression. Knockdown circFAM193B enhances mitochondrial OXPHOS function and inhibits the accumulation of reactive oxygen species and lipid peroxidation mediated by chemotherapy, which protects AML cells from oxidative stress-induced cell death. Mechanistically, circFAM193B physically interacts with arginine methyltransferase PRMT6 catalytic domain and enhances the transcription efficiency of key lipid peroxidation factor ALOX15 by decreasing H3R2me2a modification. In summary, we have identified circFAM193B was downregulated in LSCs to promote the survival of LSC by modulating energy metabolism and the redox balance in the postchemotherapy persistence of LSC. Our studies provide a conceptual advance and biological insights regarding the drug resistance of LSCs via circRNA mediated PRMT6-deposited methylarginine signaling.