Hsa_circ_0079480 promotes tumor progression in acute myeloid leukemia via miR-654-3p/HDGF axis.

Circular RNAs (circRNAs) are newly-discovered endogenous non-coding RNAs that have vital functions in regulating gene expression in tumorigenesis. Nonetheless, the function of circRNAs in acute myeloid leukemia (AML) are not yet clarified. In this analysis, hsa_circ_0079480, a novel circRNA, has been identified as being highly expressed in AML. Loss-of-function assays showed that reduction of hsa_circ_0079480 decreased the growth and stimulated apoptosis of AML cells in vitro. Furthermore, miR-654-3p was sponged by hsa_circ_0079480, and hepatoma-derived growth factor (HDGF) was targeted by miR-654-3p with respect to the fundamental mechanism. Moreover, the influence on growth and apoptosis of AML cells stimulated by hsa_circ_0079480 inhibition can be rescued by miR-654-3p inhibitor or HDGF overexpression. In summary, hsa_circ_0079480 is highly expressed in AML and drives by tumor progression via regulation of hsa_circ_0079480/miR-654-3p/HDGF axis, indicating that hsa_circ_0079480 may function as a new treatment target for AML therapy.

c-Myc, RMRP, and miR-34a-5p form a positive-feedback loop to regulate cell proliferation and apoptosis in multiple myeloma.

Long non-coding RNA (lncRNA) component of mitochondrial RNA processing endoribonuclease (RMRP) has been demonstrated to be implicated in human cancer processes. However, the role of lncRNA RMRP in multiple myeloma (MM) remains unknown. In this paper, we proved that RMRP and c-Myc were upregulated, while miR-34a-5p was downregulated in MM cell lines and bone marrows of MM patients. High RMRP expression significantly correlated with worse disease-free survival and overall survival in MM patients. c-Myc promoted RMRP transcription by directly binding to its promoter region. Knockdown of RMRP inhibited proliferation and promoted apoptosis of OPM2 and RPMI-8226 cells. Negative correlation between RMRP, and miR-34a-5p was discovered in bone marrows of MM patients. c-Myc expression was inversely correlated with miR-34a-5p in bone marrows of MM patients. Additionally, silencing of RMRP led to a marked reduction in c-Myc expression in OPM2 and RPMI-8226 cells, and this action was obviously blocked by miR-34a-5p knockdown. Moreover, upregulation of miR-34a-5p repressed proliferation and promoted apoptosis of OPM2 and RPMI-8226 cells. However, RMRP overexpression blocked these changes triggered by miR-34a-5p mimic. Besides, RMRP knockdown repressed MM tumor growth in vivo. Conclusions, RMRP functions as a miR-34a-5p sponge to promote cell proliferation and repress cell apoptosis through upregulation of c-Myc in MM.

HMGA2 regulates acute myeloid leukemia progression and sensitivity to daunorubicin via Wnt/ß-catenin signaling.

Acute myeloid leukemia (AML) is a malignant disease with an increasing prevalence in adults and children. However, valuable molecular diagnostic research is rare. In the present study, plasmids silencing and overexpressing high­mobility group AT­hook 2 (HMGA2) were respectively transfected in HL60 and NB4 cells. The effects of HMGA2 on AML cell viability, apoptosis, migration and invasion were determined by preforming MTT, flow cytometry, wound scratch and Transwell assays, respectively. Genes associated with apoptosis and Wnt signaling were evaluated by reverse transcription­quantitative (RT­q)­PCR and western blotting. AML cell sensitivity to daunorubicin (DNR) and the regulatory effects of the Wnt signaling pathway via HMGA2 following treatment with the agonist LiCl or antagonist XAV939 were detected by MTT, RT­qPCR and western blot analysis. The results revealed that the expression of HMGA2 was elevated more so in HL60, KG1, U937, Kasumi­1, THP­1 and K562 cells than in NB4 cells. Silencing HMGA2 suppressed cell viability, migration and invasion, enhanced cell apoptosis and sensitivity to DNR, and almost restored the DNR inhibitory function that was promoted by LiCl treatment. In addition, low expression of HMGA2 attenuated X­linked inhibitor of apoptosis and Bcl­2 mRNA and protein levels, and upregulated the expression of Bax and cleaved­caspase­3. Furthermore, silencing HMGA2 not only decreased Wnt and non­phospho­ß­catenin expressions, but also partially reversed the increased expressions of these proteins induced by LiCl treatment. On the other hand, overexpression of HMGA2 exhibited the opposite results after transfection in NB4 cells. The results of the present study demonstrated that HMGA2 played important roles in driving AML progression and chemosensitivity in HL60 and NB4 cells, potentially by activating the Wnt/ß­catenin signaling pathway. Therefore, it was suggested that HMGA2 may be a promising molecular marker for AML diagnosis.

Long non-coding RNA CCAT1 promotes multiple myeloma progression by acting as a molecular sponge of miR-181a-5p to modulate HOXA1 expression.

Multiple myeloma (MM) is the second most common hematological cancer all over the world. Long non-coding RNA (lncRNA) colon cancer associated transcript-1 (CCAT1) has been reported to play important roles in the development and progression of multiple human malignancies. However, little is known about its functional role and molecular mechanism in MM. The aim of this study was to investigate the clinical and biological significance of CCAT1 in MM. Our data showed that the relative expression levels of CCAT1 were significantly upregulated in MM tissues and cell lines compared with healthy donors and normal plasma cells (nPCs). High expression of CCAT1 was correlated shorter overall survival of MM patients. CCAT1 knockdown significantly inhibited cell proliferation, induced cell cycle arrest at G0/G1 phase and promoted cell apoptosis in vitro, and suppressed tumor growth in vivo. MiR-181a-5p was a direct target of CCAT1, and repression of miR-181a-5p could rescue the inhibition of CCAT1 knockdown on MM progression. In addition, CCAT1 positively regulated HOXA1 expression through sponging miR-181a-5p in MM cells.taken together, lncRNA CCAT1 exerted an oncogenic role in MM by acting as a ceRNA of miR-181a-5p. These results suggest that CCAT1 may serve as a novel diagnostic marker and therapeutic target for MM.

[Effect of SHIP-1 on Invasion, Migration and PI3K-AKT Signaling Pathway of Leukemic Cells].

OBJECTIVE: To investigate the effect of SH2-containing inositol phosphatase-1 (SHIP-1) on the proliferation, invasion and migration of human leukemia cells as well as phosphatidylinositol-3 kinase (PI3K) / protein kinase B (AKT) signaling pathway. METHODS: The overexpression vector pCDNA3.1-SHIP1 was transfected into THP-1 cells by Lipofectamine 2000. The experiment was divided into 3 groups: control group (untreated cells) and empty vector group (transfected with empty vector pCDNA3.1-NC) and overexpression group (transfected with overexpression vector pCDNA3.1-SHIP1). The cell proliferation was tected by CCK-8 assay, Transwell assay was used to evaluate the cell invasion and migration capabilities. The expressions of SHIP-1, AKT, phosphorylated AKT (pAKT), matrix metalloproteinase-9 (MMP-9) protein were analyzed by Western blot. RESULTS: The expression of SHIP-1 in overexpression group was significantly higher than that in the control group(P<0.05). Compared with the control group, the absorbance of the cells in the empty vector group was not statistically different (P>0.05), and the absorbance in overexpression group decreased significantly(P<0.05). The cell numbers of invasion and migration were not significantly different between empty and control groups(P>0.05), but those in overexpression group were significantly lower than those in the control group(P<0.05). Compared with the control group, the expression of AKT, pAKT and MMP-9 in the empty vector group was not statistically different (P>0.05); the AKT protein in overexpression group was not significantly different (P>0.05), but the pAKT and MMP-9 significantly decreased(P<0.05). CONCLUSION: SHIP-1 plays a role in inhibiting the proliferation, invasion and migration of leukemia cells, the mechanism probably relates with supressing the expression of MMP-9 by regulating PI3K/AKT signaling pathway.

LncRNA MALAT1 acts as an oncogene in multiple myeloma through sponging miR-509-5p to modulate FOXP1 expression.

Previous studies showed that Metastasis associated lung adenocarcinoma transcript 1(MALAT1) acted as an oncogene in Multiple Myeloma (MM). However, the underlying mechanism of MALAT1 in MM remains unclear. Quantitative real time-PCR(qRT-PCR) was used to determine MALAT1 expression in MM samples and cell lines. in vitro function assays were used to determine the function of MALAT1 on MM cells. Bioinformatics tools were used to predict the targets of MALAT1 and miR-509-5p, respectively. Furthermore, rescue experiments were performed to further confirm the regulation of miR-509-5p by MALAT1. In the present study, our data showed that MALAT1 expression was upregulated in MM samples and cell lines. In function assays, we confirmed that MALAT1 inhibition significantly suppressed cells proliferation, induced cells apoptosis, arrested cells in G1/S phase, and inhibited MM cells growth in vivo. Furthermore, MALAT1 was identified to function as a competitive endogenous RNA (ceRNA) for miR-509-5p to promote MM cell viability. Additionally, our results suggested that miR-509-5p targeted the 3'-UTR of FOXP1 to suppress MM cells progression. Meanwhile, our results showed that miR-509-5p inhibitors significantly abrogated the decreased expression of FOXP1 induced by MALAT1 suppression, indicating that MALAT1 could positively regulate FOXP1 expression by sponging miR-509-5p. Our findings suggested that MALAT1/miR-509-5p/FOXP1 axis was one of the key signalings in mediating MM cell growth, and further indicated that MALAT1 could act as a novel diagnostic marker and therapeutic target for the treatment of MM.

[Effects of Different Dosages of rhG-CSF on Duration of Aleucocytosis and Leukocytes Level after Chemotherapy of Patients with Hematologic Malignancies].

OBJECTIVE: To compare the effects of different dosages of rhG-CSF on duration of aleucocytosis and white blood cell counts after chemotherapy of patients with hematologic malignancies. METHODS: Ninety patients in our hospital from December 2011 to June 2016 were chosen as study objects, and all of them were divided into 3 groups: group A (rhG-CSF 200 µg/m2), group B(rhG-CSF 300 µg/m2) and group C(rhG-CSF 400 µg/m2); 30 patients from January 2004 to January 2007 were chosen as control(control group). The WBC(min) and its duration, WBC(max) and its timepoint were compared among different groups. The infection rate, incidence of side reactions and total amount of rhG-CSF used in different groups were compared. RESULTS: In control group, WBC(min) was(1.30±0.11)×109/L, its duration was (3.2±0.7)d, WBC(max) was(5.14±0.41)×109/L, and its time point was (26.1±1.8)d; these in group A were (3.14±0.23)×109/L,(2.7±1.0)d, (10.08±0.69)×109/L and (14.9±1.8)d respectively; these in group B were (3.11±0.32)×109/L, (0.9±0.5)d, (10.17±0.75)×109/L and(10.7±1.5)d respectively; these in group C were (3.15±0.30)×109/L,(0.5±0.3)d, (11.95±0.86)×109/L and (10.6±1.5)d, respectively. Compared with control group, the WBC(min) and WBC(max) were both increased significantly, the duration of WBC(min) was shortened and the timepoint of WBC(max) was moved up(P<0.05). The infection rate of group C (3.33%(1/30)) was significantly lower than that of control group(33.33%(10/30))(P<0.05), total used amount of rhG-CSF and incidence of side reactions were not statistically different among group A,B,C(P>0.05). CONCLUSION: Compared with low dosage of rhG-CSF, medium/high dosage of rhG-CSF can help to shorten duration of a leukocytosis after chemotherapy of patients.

[Change of Plasma Interleukin-16 Level in Patients with Multiple Myeloma and Its Clinical Significance].

OBJECTIVE: To investigate the change of plasma IL-16 level in patients with multiple myeloma(MM) and its clinical significance. METHODS: Sixty-two patients with multiple myeloma were admitted in our hospital from June 2008 to June 2015. Forty healthy volunteers were selected as control group. The peripheral blood of all the patients and healthy volunteers were collected before the treatment of patients. The levels of IL-16, Cys-C, LDH and ß2-MG were measured. ROC curve was used to analyze the optimal IL-16 thresholds in MM patients. Kaplan-Meier method was used to analyze the factors affecting overall survival. RESULTS: The levels of IL-16, Cys-C, LDH and ß2-MG in the MM group were significantly higher than those in the control group (P<0.05). The levels of IL-16, Cys-C, LDH and ß2-MG in patients with different ISS were significantly different (P<0.05). The levels of IL-16, Cys-C, LDH and ß2-MG in ISS III groups were higher than those in ISS I and ISS II groups(P<0.05). When the IL-16 concentration was 171.26 ng/L, the AUC was 0.787 (P<0.01), and the sensitivity and specificity were 82.25% and 75.80%, respectively, when the IL-16 threshold was predicted by ROC curve analysis. The 3-year overall survival rates of patients with IL-16≤171.26 ng/L and IL-16>171.26 ng/L were 91.93% and 51.61%, respectively (P<0.01). Multivariate analysis showed that the changes of IL-16 levels were significantly related with overall survival (P<0.01). CONCLUSION: The level of IL-16 in peripheral blood of patients with multiple myeloma has been cofirmed to be significantly elevated, and the elevated IL-16 is closely related with the prognosis.

miR-92a Inhibits Proliferation and Induces Apoptosis by Regulating Methylenetetrahydrofolate Dehydrogenase 2 (MTHFD2) Expression in Acute Myeloid Leukemia.

Aberrant expression of microRNA-92a (miR-92a) has been investigated in various cancers. However, the function and mechanism of miR-92a in acute myeloid leukemia (AML) remain to be elucidated. Our data showed that miR-92a was evidently downregulated and methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) was remarkably upregulated in AML cell lines HL-60 and THP-1. Dual luciferase reporter assay revealed that MTHFD2 was a direct target of miR-92a. Gain- and loss-of-function analysis demonstrated that MTHFD2 knockdown or miR-92a overexpression notably inhibited proliferation and promoted apoptosis of AML cell lines. Restoration of MTHFD2 expression reversed proliferation inhibition and apoptosis induction of AML cells triggered by miR-92a. Moreover, an implanted tumor model in mice indicated that miR-92a overexpression dramatically decreased tumor growth and MTHFD2 expression in vivo. Taken together, our results suggest that miR-92a inhibits proliferation and induces apoptosis by directly regulating MTHFD2 expression in AML. miR-92a may act as a tumor suppressor in AML, providing a promising therapeutic target for AML patients.