Low TYROBP expression predicts poor prognosis in multiple myeloma.

BACKGROUND: Multiple myeloma (MM) is the second most common refractory hematologic cancer. Searching for new targets and prognostic markers for MM is significant. METHODS: GSE39754, GSE6477 and GSE24080 were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) in MM versus healthy people from GSE39754 and GSE6477 were screened using limma package, and MM-related module genes were chosen with the use of Weighted gene co-expression network analysis (WGCNA), and the two were intersected using ggVennDiagram for obtaining MM-related DEGs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were carried out. Then, protein-protein interactions (PPI) analysis in String database was used to obtain hub genes, while prognosis was analyzed by survival package in GSE24080. Receiver operating characteristic (ROC) curve was adopted for evaluating diagnostic value of hub genes. Besides, univariable/multivariable Cox regression were employed to screen independent prognostic biomarkers. Gene set enrichment analysis (GSEA) was used to find possible mechanism. Finally, western-blotting and reverse transcription-polymerase chain reaction (RT-PCR) verify TYROBP expression within MM and healthy people. We performed cell adhesion and transwell assays for investigating TYROBP function in MM cell adhesion and migration. RESULTS: Through differential analyses, 92 MM-related DEGs were obtained. 10 hub genes were identified by PPI and CytoHubba. Their diagnostic and prognostic significance was analyzed. Down-regulation of genes like TYROBP, ELANE, MNDA, and MPO related to dismal MM prognosis. Upon univariable/multivariable Cox regression, TYROBP independently predicted MM prognosis. GSEA pathway was enriched, indicating that TYROBP expression affected MM development via cell adhesion molecular pathway. Upon Western-blotting and RT-PCR assays, TYROBP expression among MM patients decreased relative to healthy donors. Cell adhesion and transwell migration assays revealed increased MM cell adhesion and decreased migration upon TYROBP up-regulation. CONCLUSION: In summary, TYROBP is a potential prognostic marker for MM.

BM-MSCs display altered gene expression profiles in B-cell acute lymphoblastic leukemia niches and exert pro-proliferative effects via overexpression of IFI6.

BACKGROUND: The tumor microenvironment (TME) is a supportive environment responsible for promoting the growth and proliferation of tumor cells. Current studies have revealed that the bone marrow mesenchymal stem cells (BM-MSCs), a type of crucial stromal cells in the TME, can promote the malignant progression of tumors. However, in the adult B-cell acute lymphoblastic leukemia (B-ALL) microenvironment, it is still uncertain what changes in BM-MSCs are induced by leukemia cells. METHODS: In this study, we mimicked the leukemia microenvironment by constructing a BM-MSC-leukemia cell co-culture system. In vitro cell experiments, in vivo mouse model experiments, lentiviral transfection and transcriptome sequencing analysis were used to investigate the possible change of BM-MSCs in the leukemia niche and the potential factors in BM-MSCs that promote the progression of leukemia. RESULTS: In the leukemia niche, the leukemia cells reduced the MSCs' capacity to differentiate towards adipogenic and osteogenic subtypes, which also promoted the senescence and cell cycle arrest of the MSCs. Meanwhile, compared to the mono-cultured MSCs, the gene expression profiles of MSCs in the leukemia niche changed significantly. These differential genes were enriched for cell cycle, cell differentiation, DNA replication, as well as some tumor-promoting biofunctions including protein phosphorylation, cell migration and angiogenesis. Further, interferon alpha-inducible protein 6 (IFI6), as a gene activated by interferon, was highly expressed in leukemia niche MSCs. The leukemia cell multiplication was facilitated evidently by IFI6 both in vitro and in vivo. Mechanistically, IFI6 might promote leukemia cell proliferation by stimulating SDF-1/CXCR4 axis, which leads to the initiation of downstream ERK signaling pathway. As suggested by further RNA sequencing analysis, the high IFI6 level in MSCs somewhat influenced the gene expression profile and biological functions of leukemia cells. CONCLUSIONS: BM-MSCs in the leukemia niche have varying degrees of changes in biological characteristics and gene expression profiles. Overexpression of IFI6 in BM-MSCs could be a key factor in promoting the proliferation of B-ALL cells, and this effect might be exerted through the SDF-1/CXCR4/ERK signal stimulation. Targeting IFI6 or related signaling pathways might be an important measure to reduce the leukemia cell proliferation.

Heme oxygenase-1 inhibits the cytotoxicity of natural killer cells to acute myeloid leukemia by downregulating human leukocyte antigen-C.

BACKGROUND AIMS: Recently, immune escape has been considered as a factor leading to relapse of acute myeloid leukemia (AML). In our previous study, heme oxygenase 1 (HO-1) proved to play an essential role in the proliferation and drug resistance of AML cells. In addition, recent studies by our group have shown that HO-1 is involved in immune escape in AML. Nevertheless, the specific mechanism by which HO-1 mediates immune escape in AML remains unclear. METHODS: In this study, we found that patients with AML and an overexpression of HO-1 had a high rate of recurrence. In vitro, overexpression of HO-1 attenuated the toxicity of natural killer (NK) cells to AML cells. Further study indicated that HO-1 overexpression inhibited human leukocyte antigen-C and reduced the cytotoxicity of NK cells to AML cells, leading to AML relapse. Mechanistically, HO-1 inhibited human leukocyte antigen-C expression by activating the JNK/C-Jun signaling pathway. RESULTS: In AML, HO-1 inhibits cytotoxicity of NK cells by inhibiting the expression of HLA-C, thus causing immune escape of AML cells. CONCLUSIONS: NK cell-mediated innate immunity is important for the fight against tumors, especially when acquired immunity is depleted and dysfunctional, and the HO-1/HLA-C axis can induce functional changes in NK cells in AML. Anti-HO-1 treatment can promote the antitumor effect of NK cells and may play an important role in the treatment of AML.

[Study on the Relationship between Integrin 2A and Drug Resistance in Chronic Myeloid Leukemia].

OBJECTIVE: To explore the expression pattern and clinical significance of Integral membrane protein 2A（ITM2A） in drug resistant patients with chronic myeloid leukemia (CML). METHODS: The expression of ITM2A in CML was evaluated by qRT-PCR, Western blot and immunocytochemistry. In order to understand the possible biological effects of ITM2A, apoptosis, cell cycle and myeloid differentiation antigen expression of CML cells were detected by flow cytometry after over-expression of ITM2A. The nuderlying molecular mechanism of its biological effect was explored. RESULTS: The expression of ITM2A in bone marrow of CML resistant patients was significantly lower than that of sensitive patients and healthy donors（P<0.05）. The CML resistant strain cell K562R was successfully constructed in vitro. The expression of ITM2A in the resistant strain was significantly lower than that in the sensitive strain(P<0.05). Overexpression of ITM2A in K562R cells increased the sensitivity of K562R cells to imatinib and blocked the cell cycle in G2 phase(P<0.05), but did not affect myeloid differentiation. Mechanistically, up-regulation of ITM2A reduced phosphorylation in ERK signaling (P<0.05). CONCLUSION: The expression of ITM2A was low in patients with drug resistance of CML, and the low expression of ITM2A may be the key factor of imatinib resistance in CML.

Nuclear factor Nrf2 promotes glycosidase OGG1 expression by activating the AKT pathway to enhance leukemia cell resistance to cytarabine.

Chemotherapy resistance is the dominant challenge in the treatment of acute myeloid leukemia (AML). Nuclear factor E2-related factor 2 (Nrf2) exerts a vital function in drug resistance of many tumors. Nevertheless, the potential molecular mechanism of Nrf2 regulating the base excision repair pathway that mediates AML chemotherapy resistance remains unclear. Here, in clinical samples, we found that the high expression of Nrf2 and base excision repair pathway gene encoding 8-hydroxyguanine DNA glycosidase (OGG1) was associated with AML disease progression. In vitro, Nrf2 and OGG1 were highly expressed in drug-resistant leukemia cells. Upregulation of Nrf2 in leukemia cells by lentivirus transfection could decrease the sensitivity of leukemia cells to cytarabine, whereas downregulation of Nrf2 in drug-resistant cells could enhance leukemia cell chemosensitivity. Meanwhile, we found that Nrf2 could positively regulate OGG1 expression in leukemia cells. Our chromatin immunoprecipitation assay revealed that Nrf2 could bind to the promoter of OGG1. Furthermore, the use of OGG1 inhibitor TH5487 could partially reverse the inhibitory effect of upregulated Nrf2 on leukemia cell apoptosis. In vivo, downregulation of Nrf2 could increase the sensitivity of leukemia cell to cytarabine and decrease OGG1 expression. Mechanistically, Nrf2-OGG1 axis-mediated AML resistance might be achieved by activating the AKT signaling pathway to regulate downstream apoptotic proteins. Thus, this study reveals a novel mechanism of Nrf2-promoting drug resistance in leukemia, which may provide a potential therapeutic target for the treatment of drug-resistant/refractory leukemia.

Nrf2 overexpression increases the resistance of acute myeloid leukemia to cytarabine by inhibiting replication factor C4.

Drug resistance is a key factor in the treatment failure of acute myeloid leukemia (AML). Nuclear factor E2-related factor 2 (Nrf2) plays a crucial role in tumor chemotherapy resistance. However, the potential mechanism of Nrf2 regulating DNA mismatch repair (MMR) pathway to mediate gene-instability drug resistance in AML is still unclear. Here, it was found that Nrf2 expression was closely related to the disease progression of AML as well as highly expressed in AML patients with poor prognostic gene mutations. Meanwhile, it was also found that the expression of Nrf2 was significantly negatively correlated with DNA MMR gene replication factor C4 (RFC4) in AML. CHIP analysis combined with luciferase reporter gene results further showed that Nrf2 may inhibit the expression of RFC4 by its interaction with the RFC4 promoter. In vitro and vivo experiments showed that the overexpression of Nrf2 decreased the killing effect of chemotherapy drug cytarabine (Ara-C) on leukemia cells and inhibited the expression of RFC4. Mechanistically, The result that Nrf2-RFC4 axis mediated AML genetic instability drug resistance might be received by activating the JNK/NF-κB signaling pathway. Taken together, these findings may provide a new idea for improving AML drug resistance.

An Analysis of the Willingness to the COVID-19 Vaccine Booster Shots among Urban Employees: Evidence from a Megacity H in Eastern China.

Many studies have shown that urban workers may have a higher acceptance rate of coronavirus disease (COVID-19) vaccine uptake compared to their rural counterparts. As Omicron spreads globally, the COVID-19 booster vaccination has been acknowledged as the primary strategy against this variant. In this study, we identify factors related to the willingness of workers in megacities to take the vaccine booster shots and their main reasons accounting for their booster willingness. This research survey was conducted in megacity H in eastern China, and a total of 1227 employees from different industries were interviewed. The study at hand examines the relationship between various characteristics (including both economic and non-economic factors) of urban employees and their intention/desire to accept the COVID-19 booster shoots. The survey results show that some characteristics, namely work organization, vaccine knowledge, and social network, affect their intention to take COVID-19 vaccine booster shots. Urban employees with a strong work organization, a high degree of vaccine knowledge, and a dense social capital are more likely to receive booster injections than other employees. Therefore, work organization, vaccine knowledge, and social networks provide fundamental entry points for designing enhanced injection strategies to increase the acceptance of COVID-19 vaccines among employees in megacities.

Overexpressed mitogen-and stress-activated protein kinase 1 promotes the resistance of cytarabine in acute myeloid leukemia through brahma related gene 1-mediated upregulation of heme oxygenase-1.

Drug resistance remains a major challenge in the current treatment of acute myeloid leukemia (AML). Finding specific molecules responsible for mediating drug resistance in AML contributes to the effective reversal of drug resistance. Recent studies have found that mitogen- and stress-activated protein kinase 1 (MSK1) is of great significance in the occurrence and development of tumors. In the current study, MSK1 was found highly expressed in drug-resistant AML patients. Heme oxygenase-1 (HO-1) has been previously validated to be associated with drug resistance in AML. Our study revealed a positive correlation between MSK1 and HO-1 in patient samples. In vitro experiments revealed that the sensitivity of AML cell lines THP-1 and U937 to cytarabine (Ara-C) significantly decreased after overexpression of MSK1. Meanwhile, downregulation of MSK1 by siRNA transfection or treatment of pharmacological inhibitor SB-747651A in AML cell lines and primary AML cells enhanced the sensitivity to Ara-C. Flow cytometry analysis showed that downregulation of MSK1 in AML cells accelerated apoptosis and arrested cell cycle progression in G0/G1 phase. However, the increased cell sensitivity induced by MSK1 downregulation was reversed by the induction of HO-1 inducer Hemin. Through further mechanism exploration, real-time PCR, immunofluorescence and Western blot analysis demonstrated that brahma related gene 1 (BRG1) was involved in the regulatory effect of MSK1 on HO-1. High expression of MSK1 could promote the resistance of AML through BRG1-mediated upregulation of HO-1. Downregulation of MSK1 enhanced the sensitivity of AML cells to Ara-C. Our findings provide novel ideas for developing effective anti-AML targets.

Mesenchymal Stem Cells With Cancer-Associated Fibroblast-Like Phenotype Stimulate SDF-1/CXCR4 Axis to Enhance the Growth and Invasion of B-Cell Acute Lymphoblastic Leukemia Cells Through Cell-to-Cell Communication.

Background: Bone marrow mesenchymal stem cells (BM-MSCs) are the stromal cells in the leukemia microenvironment, and can obtain cancer-associated fibroblast (CAF)-like phenotype under certain conditions to further promote leukemia progression. However, the mechanism of MSCs with CAF-like phenotype interacting with leukemia cells in B-cell acute lymphoblastic leukemia (B-ALL) and promoting the progression of B-ALL remains unclear. Methods: Mesenchymal stem cells with CAF-like phenotype were obtained by treating MSCs with recombinant human transforming growth factor-ß (rhTGF-ß), hereafter referred to as TGF-ß conditioned MSCs. In vivo mouse model experiments, in vitro transwell chamber experiments, three-dimensional (3D) cell culture models, lentiviral transfection and other experimental methods were used to investigate the possible mechanism of the interaction between TGF-ß conditioned MSCs and leukemia cells in promoting the growth, migration and invasion of B-ALL cells. Results: Compared with untreated MSCs, TGF-ß conditioned MSCs significantly promoted the growth and proliferation of leukemia cells in mice, and increased the expression of CXCR4 in tumor tissues. In vitro cell experiments, TGF-ß conditioned MSCs obviously promoted the migration and invasion of Nalm-6/RS4;11 cells, which were effectively blocked by the CXCR4 inhibitor AMD3100, thereby inhibiting the secretion of MMP-9 in TGF-ß conditioned MSCs and inhibiting the activation of the PI3K/AKT signaling pathway in leukemia cells. Further, findings were made that the interaction between TGF-ß conditioned MSCs and leukemia cells were mediated by the interaction between the integrin receptor α5ß1 on the surface of leukemia cells and the increased expression of fibronectin on TGF-ß conditioned MSCs. AMD3100 could weaken such effect by reducing the expression of integrin α5ß1 on leukemia cells. Further regulation of integrin ß1 could effectively interfere with the interaction between TGF-ß conditioned MSCs and leukemia cells. Conclusion: Mesenchymal stem cells with CAF-like phenotype could be a key factor in promoting the growth and invasion of B-ALL cells, and the SDF-1/CXCR4 axis might be a significant factor in mediating the communication of MSCs with CAF-like phenotype and leukemia cells. To prevent the progression of B-ALL cells, blocking the SDF-1/CXCR4 axis with AMD3100 or targeting integrin ß1 might be a potential therapeutic strategy.

TANK-binding kinase 1 inhibitor GSK8612 enhances daunorubicin sensitivity in acute myeloid leukemia cells via the AKT-CDK2 pathway.

PURPOSE: It has been established in previous studies that TANK-binding kinase 1 (TBK1) is upregulated in malignant tumors and is therefore associated with poor prognosis. However, the role of TBK1 in acute myeloid leukemia (AML) remains unclear. In this study, we investigated the expression levels and the function of TBK1 in AML. METHODS: First, TBK1 expression was detected and analyzed using Western blot and qRT-PCR. Then, GSK8612, a novel TBK1 inhibitor, and TBK1-specific siRNA (si-TBK1) were used to inhibit TBK1 function and expression. The effects of TBK1 inhibition on AML were investigated first through a cell counting kit (CCK-8) assay, followed by trypan blue staining to assess cell apoptosis and cell cycle progression in vitro. Finally, the signaling pathway activities in HL-60 and Kasumi-1 cells and patients' mononuclear cells (MNCs) were explored using western blot. RESULTS: We found a significantly higher TBK1 expression in AML patients with poor prognoses. GSK8612 successfully inhibited TBK1 expression, resulting in the increased sensitivity of AML cells to daunorubicin. Mechanistically, TBK1 inhibition (by GSK8612 and si-TBK1) regulated cyclin-dependent kinase 2 (CDK2) levels in AML cells via the AKT pathway. Moreover, it was observed that the inhibition of protein kinase B (AKT) activity also resulted in the increased sensitivity of AML cell lines to daunorubicin, validating the relationship between TBK1 and the AKT-CDK2 pathway. Similar results were obtained in MNCs from patients with AML. CONCLUSION: TBK1 is a potential prognostic factor for AML, and its inhibition may improve the sensitivity of AML cells to daunorubicin. This regulatory effect is predicted to involve the TBK1-AKT-CDK2 pathway.

[Sensitivity of distortion product otoacoustic emissions and auditory brain-stem response in neonatal hearing screening, a comparative study].

OBJECTIVE: To investigate the sensitivity of distortion product otoacoustic emissions (DPOAE) and auditory brain-stem response (ABR) in neonatal hearing screening. METHODS: DPOAE and ABR were conducted on 99 neonates (198 ears) at risk of hearing impairment as initial screening tests. One month later rescreening tests were conducted: DPOAE was conducted again on those ears failing this test during the initial screening test and ABR was conducted again on the ears failing this test during the initial screening test Those ears failing the DPOAE and ABR tests during the rescreening tests were examined with electric otoscope, diagnostic ABR, etc. to get confirmed diagnosis. RESULTS: 54 ears (27%) failed the DPOAE test during the initial screening and 14 out of the 54 ears (14/198, 7%) still failed the DPOAE test during the rescreening. 26 ears (12%) failed the ABR test during the initial screening and 9 out of the 16 ears (9/198, 4.5%) still failed this test during the rescreening. Two babies were confirmed as with severe sensorineural hearing loss, one unilateral and one bilateral. The sensitivity was 97% for DPOAE and 99% for ABR. CONCLUSION: ABR is a little bit more sensitive then DPOAE in neonatal hearing screening. Two-stage testing procedure increases the sensitivity of neonatal hearing screening.