LncRNA SNHG5 upregulation induced by YY1 contributes to angiogenesis via miR-26b/CTGF/VEGFA axis in acute myelogenous leukemia.

Acute myelogenous leukemia (AML) is the most common acute leukemia in adults. Despite great progress has been made in this field, the pathogenesis of AML is still not fully understood. We report here the biological role of lncRNA small nucleolar RNA host gene 5 (SNHG5) in the pathogenesis of AML and the underlying mechanisms. The results showed that lncRNA SNHG5 was highly expressed in AML cancer cell lines. In vitro studies displayed that inhibition of SNHG5 with shRNA resulted in suppression of survival, cell cycle progression, migration/invasion of AML and capacity of adhesion and angiogenesis in human umbilical vein endothelial cells. Mechanistic studies revealed a SNHG5/miR-26b/connective tissue growth factor (CTGF)/vascular endothelial growth factor A (VEGFA) axis in the regulation of AML angiogenesis. Finally, Yin Yang 1 (YY1) was found to transactivate and interact with SNHG5 promoter, leading to the upregulation of SNHG5 in AML. Collectively, upregulation of lncRNA SNHG5 mediated by YY1, activates CTGF/VEGFA via targeting miR-26b to regulate angiogenesis of AML. Our work provides new insights into the molecular mechanisms of AML.

LncRNA-MALAT1 regulates proliferation and apoptosis of acute lymphoblastic leukemia cells via miR-205-PTK7 pathway.

Long non-coding RNA (lncRNA) MALAT1 has been confirmed to function as an oncogene in various solid tumors. MALAT1 level has been shown to be upregulated in relapsed acute lymphoblastic leukemia (ALL) patients, but the mechanism is unclear. This study aims to investigate the functional roles and underlying mechanisms of MALAT1 in ALL. MALAT1 and miR-205 expression were assessed by real-time quantitative polymerase chain reaction (RT-qPCR). MTT assay and flow cytometry were performed to evaluate cell proliferation and apoptosis, respectively. Protein level of protein tyrosine kinase-7 (PTK7) was detected by Western blot assay. Dual luciferase reporter assay was conducted to confirm the binding of MALAT1 and miR-205, as well as miR-205 and PTK7. The levels of MALAT1 and PTK7 were upregulated in ALL samples. In contrast, miR-205 level was downregulated in ALL in ALL samples. Moreover, MALAT1 silencing or miR-205 overexpression restrained proliferation and promoted apoptosis of ALL cells. Mechanistically, MALAT1 sponged miR-205 to regulate PTK7 expression. In summary, MALAT1 affected ALL cell proliferation and apoptosis via regulating miR-205-PTK7 axis. Our results suggest that MALAT1-miR-205-PTK7 axis participates in the proliferation and apoptosis of ALL, which may provide a potential treatment target for ALL.

Long non-coding RNA MALAT1 triggers ferroptosis via interaction with FUS to enhance ACSF2 mRNA stabilization in septic acute kidney injury.

Septic acute kidney injury (AKI) is a fatal disease in the intensive care unit, with ferroptosis playing a crucial role in its pathogenesis. Long non-coding RNA (LncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been implicated in septic-induced AKI inflammation and apoptosis. However, its regulatory role in ferroptosis and underlying mechanisms remain unclear. In vivo and in vitro models of septic AKI were established using cecal ligation and puncture (CLP) and lipopolysaccharide (LPS) challenge, respectively. Serum levels of creatinine (Cr), blood urea nitrogen (BUN), kidney injury molecule-1 (Kim-1), neutrophil gelatinase-associated lipocalin (NGAL), and inflammatory cytokine in kidney tissues were determined by ELISA kits. Histopathological alterations and apoptosis were evaluated by HE staining and TUNEL. Ferroptosis was accessed by measuring MDA, GSH, Fe2+, total and lipid ROS levels, and mitochondrial ultrastructure changes. Target molecular levels were determined using RT-qPCR, Western blotting, and immunofluorescence. Interactions among MALAT1, acyl-CoA synthetase family member 2 (ACSF2) and FUS RNA binding protein (FUS) were validated by RIP and RNA-pull down. MALAT1 level was significantly elevated in both in vivo and in vitro septic AKI models, of which knockdown impeded ferroptosis to alleviate septic AKI. Mechanistically, high MALAT1 expression increased ACSF2 mRNA stability via interaction with FUS. Rescue experiments showed that ACSF2 overexpression partially reversed the ferroptosis inhibition mediated by MALAT1 silencing. MALAT1 induces ferroptosis and exacerbates septic AKI by stabilizing ACSF2 mRNA with the assistance of FUS. These findings provide theoretical evidence for MALAT1 as a potential therapeutic target for septic AKI.

[Deletions and rearrangements of PAX5 gene in B-lineage acute lymphoblastic leukemia].

OBJECTIVE: To determine the frequency paired-box domain 5 (PAX5) gene alterations in B-lineage acute lymphoblastic leukemia (B-ALL) harboring 9p abnormalities and its implication for clinical prognosis. METHODS: Bacterial artificial chromosomes RP11-344B23 and RP11-652D9 encompassing the PAX5 gene were selected. DNA was extracted with conventional method and labeled with fluorescein by nicking transition. Fluorescence in situ hybridization (FISH) was used to determine the rearrangement or deletion of the PAX5 gene in B-ALL harboring chromosome 9p abnormalities. Clinical and laboratory features of patients were analyzed. RESULTS: Fifty cases were analyzed with FISH. Complete deletion was observed in 23 patients (46%), partial deletion was observed in 2 patients (4%), and rearrangement was detected only in 1 case. The total frequency of abnormalities was 52% (26/50). No significant difference was found in clinical features of patients with or without PAX5 rearrangement or deletion. CONCLUSION: The frequency of PAX5 gene alterations in B-ALL harboring 9p abnormalities was 52%. However, no significant difference was found between patients with and without PAX5 alterations.

Using JAK inhibitor to treat cytokine release syndrome developed after chimeric antigen receptor T cell therapy for patients with refractory acute lymphoblastic leukemia: A case report.

RATIONALE: Significant concerns about the adverse effects following chimeric antigen receptor T cell (CAR-T) therapy are still remained including cytokine release syndrome (CRS). In rare circumstances, CRS may be refractory to tocilizumab and/or corticosteroids, a new treatment is needed for the management of CRS. PATIENT CONCERNS: We present a case of a 20-year-old male patient with acute lymphoblastic leukemia developed CRS after CD19/CD22 bispecific CAR-T treatment. DIAGNOSIS: The patient was diagnosed with BCR-ABL(P210) positive B-ALL and developed CRS after CD19/CD22 bispecific CAR-T treatment. INTERVENTIONS: Tocilizumab and methylprednisolone were administered, unfortunately the patient's symptoms of CRS were still not resolved. Another methylprednisolone and ruxolitinib were administered. OUTCOMES: The persistent fever and hypotension of this patient achieved a rapid clinical remission within hours after ruxolitinib administration. LESSONS: Ruxolitinib can be used as an alternative therapeutic approach for severe and refractory CRS without impairing CAR-T amplification and anti-tumor effect.

LncRNA PVT1 promotes the malignant progression of acute myeloid leukaemia via sponging miR-29 family to increase WAVE1 expression.

LncRNA PVT1 has been demonstrated to be upregulated in acute myeloid leukaemia (AML) patients and indicates a poor prognosis. Nevertheless, its role in AML remains obscure. This study investigated the regulatory role and potential mechanisms of PVT1 in the progression of AML. Expression of PVT1, miR-29 family and WAVE1 was detected by quantitative real-time polymerase chain reaction. CCK8 and EdU assays were performed to assess the proliferation of AML cells. Cell cycle and apoptosis were determined by propidium iodide (PI) staining and Annexin V/PI staining on a flow cytometer. Transwell assay was carried out to evaluate the migration and invasion abilities. The interaction between miR-29 family and PVT1/WAVE1 was confirmed by dual luciferase reporter assay and RNA immunoprecipitation assay. The protein levels of WAVE1, Bcl-2, Bax, cleaved Caspase 3, cyclin D1, and p21 were detected by western blotting. Xenograft transplantation was performed to determine the tumourigenicity of AML cell in vivo. PVT1 expression was significantly increased in AML patient samples and cells, which positively correlated with WAVE1 expression. Silencing of PVT1 restrained growth, migration and invasion, while inducing apoptosis of AML cells. Moreover, PVT1 acted as a sponge for miR-29 family to increase WAVE1 expression in AML cells. Overexpression of WAVE1 partly counteracted PVT1 knockdown-induced anti-tumour effects on AML cells in vitro and xenograft tumour in vivo. PVT1 facilitated the progression of AML via regulating miR-29 family/WAVE1 axis, which supported the conclusion that PVT1 may be a promising therapeutic target for AML.

Long Noncoding RNA H19 Promotes Tumorigenesis of Multiple Myeloma by Activating BRD4 Signaling by Targeting MicroRNA 152-3p.

Multiple myeloma (MM) accounts for over twenty percent of hematological cancer-related death worldwide. Long noncoding RNA (lncRNA) H19 is associated with multiple tumorigenesis and is increased in MM, but the underlying mechanism of H19 in MM is unclear. In this study, the expression of H19, microRNA 152-3p (miR-152-3p), and BRD4 in MM patients was evaluated by quantitative real-time PCR (qRT-PCR) and Western blotting. Colony formation and flow cytometry analysis were used to determine the effects of H19 and miR-152-3p on MM cell proliferation, apoptosis, and cell cycle. A luciferase reporter assay was conducted to confirm the interaction among H19, miR-152-3p, and BRD4. A nude mouse xenograft model was established, and the cell proliferation and apoptosis were evaluated by immunohistochemistry (IHC) staining and terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling assay. We found that levels of H19 and BRD4 were upregulated and the expression of miR-152-3p was downregulated in MM patients. Dual luciferase reporter assay showed H19 targeted miR-152-3p to promote BRD4 expression. Knockdown of H19 repressed proliferation and enhanced apoptosis and cell cycle G1 arrest by upregulating miR-152-3p in MM cells. Furthermore, H19 knockdown suppressed the growth of xenograft tumor, reduced Ki-67 and BRD4 levels, and increased cell apoptosis in xenograft tumor tissues. Taking these results together, H19 knockdown suppresses MM tumorigenesis via inhibiting BRD4-mediated cell proliferation through targeting miR-152-3p, implying that H19 is a promising biomarker and drug target for MM.

I-BET151 suppresses osteoclast formation and inflammatory cytokines secretion by targetting BRD4 in multiple myeloma.

Background: Multiple myeloma (MM) is an incurable hematologic cancer, accompanied by excessive osteoclast formation and inflammatory cytokine secretion. The mechanisms by which bromodomain and extra-terminal domain (BET) protein inhibitor I-BET151 regulates osteoclast differentiation and inflammatory cytokine secretion in MM are largely unknown. Methods: The isolated peripheral blood mononuclear cells from normal or patients with MM were treated with receptor activator of NF-κB ligand (RANKL) and M-CSF to induce osteoclast differentiation. RAW 264.7 cells were treated with RANKL. I-BET151 was applied to investigate the effects of BRD4 inhibition on osteoclast formation and inflammatory cytokine secretion. Osteoclast formation was determined by tartrate-resistant acid phosphatase (TRACP) staining. The expression of osteoclast-specific genes TRACP, matrix metalloproteinase-9 (MMP-9), cathepsin K (Ctsk), and c-Src was tested using quantitative real-time PCR. And the level of inflammatory cytokines TNF-α, IL-1ß, and IL-6 was assessed by ELISA. Tumor necrosis factor receptor-associated factor 6 (TRAF6), BRD4, nuclear and cytoplasm p65, IκB-α, nuclear factor of activated T cells cytoplasmic (NFATc1), and osteoprotegerin (OPG) expression were measured by Western blotting. RNAi technology was applied to knock down BET family member BRD4. Results: I-BET151 dose-dependently suppressed osteoclast formation, inhibited the levels of osteoclast-specific genes TRACP, MMP-9, Ctsk, and c-Src and inflammatory cytokines TNF-α, IL-1ß, and IL-6 secretion in peripheral blood mononuclear cells and RAW 264.7. I-BET151 inhibited the protein levels of BRD4 and NFATc1, increased OPG expression, and suppressed IκB-α degradation and p65 nuclear translocation. Further, the effects of I-BET151 on osteoclast formation, osteoclast-specific genes expression, inflammatory cytokine secretion, and NF-κB inhibition were promoted by BRD4 knockdown. Conclusion: I-BET151 inhibits osteoclast formation and inflammatory cytokine secretion by targetting BRD4-mediated RANKL-NF-κB signal pathway and BRD4 inhibition might be beneficial for MM treatment.

[RNAi-mediated Silencing of CXCR4 Inhibits the Adhesion, Invasion and Tumorigenicity of Acute Monocytic Leukemic Cell Line SHI-1].

OBJECTIVE: To investigate the effect of CXCR4 gene on the proliferation, adhesion, invasion and tumorigenicity of a human monocytic leukemic cell line SHI-1. METHODS: The lentivirus vector silencing the expression of CXCR4 was constructed for infection of SHI-1 cells silencing expression of CXCR4 in SHI-1 cells. The expression of CXCR4, MMP-2 and MMP-9 was detected by real time PCR. The expression of CXCR4 on membrane of SHI-1 cells was detected by flow cytometry. The SHI-1 cell proliferation ability was detected by MTT. The co-culture system of the leukemia cells and bone marrow stromal cells was used to detect the adhesion and migration ability of leukemia cells. SHI-1 cells were inoculated subcutaneously in nude mice to investigate the growth ability in vivo. RESULTS: After SHI-1 cells were infected by lentivirus silencing expression of CXCR4, the expression of CXCR4 mRNA in SHI-1 CXCR-4i cells decreased by 76% as compared with expression of SHI-1/NC of negative control virus, the expression of CXCR4 on membrane of SHI-1/CXCR4i obviously downregulated; the expression of MMP-2 and MMP-9 in SHI-1/CXCRi cells also declined by 63% and 62% respectively; the proliferation ability of SHI-1/CXCR4i in vitro did not obviously changed, but the adhesion and trans-matrigel invasion ability significantly decreased, the SHI-1/CXCR4i cells could not form neoplasm subcutaneously in mice, but the SHI-1 and SHI-1/NC cells could form neoplasm subcutaneously in mice, and there was no significant difference in volumn of neoplasm mass. CONCLUSION: The silencing expression of CXCR4 can decline the adhesion and migration ability of SHI-1 cells, and can completely suppress the formation of neoplasm subcutaneously, so the CXCR4 may serve as a target for treating leukemia.

[A clinical and laboratory study of TCF3-PBX1 positive adult acute lymphoblastic leukemia.].

OBJECTIVE: To explore the morphology, immunophenotype, cytogenetics and clinical features of TCF3-PBX1 fusion gene positive adult acute lymphoblastic leukemia (ALL). METHODS: R banding was used to analyze conventional cytogenetics (CC), interphase fluorescence in situ hybridization (iFISH) and RT-PCR to detect the TCF3-PBX1 fusion gene, and flow cytometry to immunophenotype. The clinical and laboratory features and long-term follow-up of the patients were analyzed. RESULTS: The incidence of 19 TCF3-PBX1-positive adult ALL was 3.13% of total ALL patients. Of them, 12 and 7 cases were diagnosed as L(1) and L(2) morphology respectively; 7 cases with balanced translocation of chromosome 1 and 19; 10 with der(19) t(1;19) formed from unbalanced translocation and 2 with normal karyotypes. TCF3-PBX1 fusion gene was detected by RT-PCR in 9 cases, and by iFISH in 17. 16 cases were B-phenotype and the other 2 T-phenotype; 17 cases had lymph node, spleen or liver infiltration. Of 18 patients received chemotherapy, 17 (94.7%) achieved complete remission (CR); the median relapse-free survival (RFS) and median overall survival was 3.2 months and 7.2 months, respectively. CONCLUSIONS: TCF3-PBX1-positive adult ALL had unique clinical and pathological features with high remission rate, high relapse rate and short survival time and should be considered to receive intensified treatment strategies. iFISH combined with CC and RT-PCR can increase the detection rate of t(1;19)/TCF3-PBX1 fusion gene.