Chromosomal aberrations and gene mutations have been considered to be the major reasons for high recurrence rates and poor survival among acute myeloid leukemia (AML) patients. However, the underlying molecular mechanism of AML gene mutation remains largely unclear. Here, we show that SPAG6 (sperm-associated antigen 6), one of the most markedly increased SPAG genes in AML, significantly contributed to the proliferation and migration of leukemic cells. SPAG6 was highly expressed in AML, and its upregulation was negatively correlated with the prognosis of the disease. In vitro, SPAG6 promoted the proliferation and migration of leukemia cells and promoted cell cycle progression from the G1 phase to the S phase. In vivo, low expression of SPAG6 reduced the proliferation and infiltration of leukemia cells and prolonged the survival of xenograft tumor mice. Furthermore, immunoprecipitation and mass spectrometry analysis showed that SPAG6 interacts with MYO1D (myosin 1D). Specifically, overexpression of SPAG6 promoted the translocation of MYO1D into the cell membrane, thus upgrading the expression level of the EGFR family and thereby promoting the progression of AML. Overall, our study found that SPAG6 combined with MYO1D and translocated MYO1D from the cytosol to the cytomembrane, which induced the PI3K (phosphoinositide 3-kinase)/AKT (protein kinase B) signaling and ERK (extracellular signal-regulated kinase) signaling pathway to regulate the growth and prognosis of AML. SPAG6 may become a new target gene for the treatment of AML.

Purpose: To investigate the clinical characteristics, etiology, and risk factors of bacterial bloodstream infection (BSI) in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. This study also aimed to provide a clinical basis for early identification of high-risk patients and optimization of empirical antimicrobial treatment. Patients and Methods: This is a retrospective study of clinical data during agranulocytosis from 331 patients with hematological malignancies who underwent allo-HSCT at our institute between January 2016 and December 2022. The incidence, distribution and drug resistance patterns, and the risk factors of BSI were analyzed. Results: Among the 331 HSCT patients, 250 had febrile neutropenia and 45 cases were found to have BSI. The incidence of BSI in patients with agranulocytosis fever was 18% (45/250). A total of 48 pathogens were isolated during BSI episodes, gram-negative bacteria (GNB) accounted for 70.8% (34/48), gram-positive bacteria (GPB) for 29.2% (14/48). Multivariate analysis revealed that ≥grade 2 acute graft-versus-host disease (aGVHD) and previous BSI within 6 months before HSCT were independently associated with an increased occurrence of BSI. Coagulase-negative staphylococci (CoNS) and Escherichia coli were the most commonly isolated GPB and GNB, respectively. A total of 32 GNB were tested for drug susceptibility, the detection rate of carbapenem-resistant Enterobacteriaceae (CRE) was 12.5% (4/32), and extended-spectrum β-lactamase (ESBL) accounted for 56.3% (18/32). Conclusion: BSIs are still a common and severe complication after allo-HSCT. In our center, BSIs in allo-HSCT patients are dominated by gram-negative bacteria and the resistance rate to carbapenem drugs is high. Risk factors for BSI during agranulocytosis were previous BSI within 6 months before HSCT and ≥grade 2 aGVHD.

Introduction: As a malignant hematological disease, the incidence of acute myeloid leukemia (AML) has exhibited an upward trend in recent years. Nevertheless, certain limitations persist in the treatment of AML. Sperm-associated antigen 6 (SPAG6) has been implicated in the onset and progression of various human cancers, with its expression levels significantly elevated in AML. Consequently, we undertook a series of experiments to investigate the role and underlying mechanisms of SPAG6 in AML cell lines.Methods: In the in vitro experiments of this study, DEPs and GO and KEGG enrichment analysis subsequent to SPAG6 down-regulation were detected by TMT. CCK8 was employed to determine cell viability. The levels of apoptosis and ROS were measured by flow cytometry. In the in vivo experiments, a xenografted tumor model was constructed, and the expression of SPAG6 and GSTP1 in tumor tissues was detected by IHC.Results: Ultimately, our findings indicated that over-expression of SPAG6 promoted cell growth and decreased reactive oxygen species (ROS) and malondialdehyde levels. Furthermore, SPAG6 knockdown was found to diminish mitochondrial membrane potential and facilitate cell apoptosis. In vivo, SPAG6 could also promote tumor growth, suggesting that SPAG6 may serve as a pro-tumor factor. In addition, daunorubicin (DNR) may cause oxidative stress and initiate apoptosis, resulting in oxidative damage to AML cells. However, the overexpression of SPAG6 may attenuate the efficacy of DNR. This was due to SPAG6 promoted GSTP1 expression, thereby reducing ROS levels. Simultaneously, the elevation of GSTP1 and JNK complex may reduce the expression of p-JNK and inhibit the activation of JNK pathway, which might inhibit cell apoptosis.Discussion: In conclusion, our experiments suggested that upregulated SPAG6 might mitigate the pro-apoptotic effects of DNR through ROS/JNK MAPK axis in a GSTP1-dependent manner.

The prognosis of B cell acute lymphoblastic leukemia (B-ALL) is poor, primarily due to drug resistance and relapse. Ga15, encoded by GNA15, belongs to the G protein family, with G protein-coupled receptors playing a crucial role in multiple biological process. GNA15 has been reported to be involved in various malignancies; however, its potential role in B-ALL remain unknown. In this study, high expression of GNA15 in B-ALL was observed in multiple databases. We further confirmed an increased transcriptional level of GNA15 in newly diagnosed B-ALL patients which was closely correlated with relapse. We showed that GNA15 promoted cell growth, inhibited apoptosis and enhanced drug resistance in leukemia cell lines. Metabolomics analysis revealed a significant enrichment of fatty acid oxidation (FAO) according to the GNA15 expression. We further confirmed that GNA15 could enhance FAO process as evidenced by the upregulation of key molecules involved in FAO including carnitine palmitoyl transferase1 (CPT1), CPT2 and CD36. And inhibition of FAO using etomoxir partially reversed the drug resistance caused by high expression of GNA15. Mechanism study showed that GNA15 promoted FAO by up-regulation of AMPK phosphorylation thus leading to survival advantage in leukemia cells. In conclusion, we observed elevated GNA15 transcript levels in B-ALL, which were associated with relapse. GNA15 could induce drug resistance though activation of the AMPK/FAO axis in leukemia cell lines. Targeting GNA15 and FAO may represent potential therapeutic strategy for improving the prognosis of B-ALL.

As a multifunctional scavenger receptor, stabilin‐1 (STAB1) has been identified to induce chronic inflammation and promote cancer progression. Although in silico studies from multiple data sets showed that STAB1 might facilitate the progression of acute myeloid leukemia (AML) and drug resistance, the real impacts of STAB1 expression on AML patients and the detailed mechanisms remain unclear. Herein, we found that a higher expression of STAB1 is associated with a worse prognosis in AML patients. Subsequent in vitro experiments demonstrated that STAB1 knockdown suppressed proliferation and promoted apoptosis through regulating the IKK/NF‐κB pathway in human AML cell lines HEL and NB4. In addition, in vivo studies showed that STAB1 silencing prolonged survival, reduced proliferation, and inhibited aggressiveness of AML cells in xenograft mouse models. Moreover, we investigated the impact of STAB1 expression in AML cells on macrophage differentiation and found that co‐culture of macrophages with conditioned medium from STAB1‐knockdown AML cells reduced M2 polarization of macrophages. Taken together, our study suggests that STAB1 promotes growth and aggressiveness of AML cells through activating the IKK/NF‐κB pathway while also regulating M2 macrophage polarization within the chronic inflammatory environment. Therefore, targeting STAB1 could be a potential therapeutic strategy for treating AML.