Inhibition of PRAME Expression Causes Cell Cycle Arrest and Apoptosis In Leukemic Cells

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1695-1695
Author(s):  
Norina Tanaka ◽  
Yan-Hua Wang ◽  
Masayuki Shiseki ◽  
Minoko Takanashi ◽  
Toshiko Motoji
Keyword(s):  
Cell Cycle ◽  
Acute Leukemia ◽  
Western Blot ◽  
Real Time ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Caspase 3 ◽  
S Phase ◽  
Leukemic Cells ◽  
Rt Pcr

Abstract Abstract 1695 Introduction: The preferentially expressed antigen of melanoma (PRAME) was originally described as a tumor-associated antigen recognized by autologous cytotoxic T cells against a melanoma surface antigen. PRAME seems to act as a dominant repressor of retinoic acid receptor (RAR) signaling, but the function of PRAME in leukemia remains unclear. In the present study, we clarified the function of PRAME in leukemia, by the method of small interfering RNA (siRNA)-induced knockdown of PRAME using a leukemic cell line. To elucidate the clinical significance of PRAME expression in acute leukemia, especially its role at the relapse of disease, expression of PRAME mRNA levels and cell cycle profiles were analyzed in acute leukemia at the time of diagnosis and relapse in paired samples. Methods: The K562 cell line was used in siRNA experiments. After PRAME siRNA transfection, the effect on cell growth was examined by colony formation assay and cell counts in liquid culture. Furthermore, cell cycle analysis and apoptotic assays (annexinV assay and caspase-3 activity assay) were performed to assess the time course from day 1 to day 6. At the same time, the possible changes in various gene expressions and protein levels were analyzed by quantitative real-time RT-PCR and western blot analysis. As clinical samples, PRAME mRNA levels were measured in a total of 44 acute leukemia patients. We also examined the relationship between PRAME expression and the percentages of S phase in leukemic cells taken from 35 paired acute leukemia patients from whom sufficient blast cells were obtained. Results: A significant decrease in cell growth was observed in liquid culture and colony formation assay of the PRAME-inhibited cells. At the same time, cell cycle analysis showed a significant decrease of cells in the S phase and increase of cells in the G0/G1 phase in PRAME siRNA-treated cells. Among the cell cycle related genes analyzed with quantitative real-time RT-PCR, a clear increase of p27 expression was observed between day 3 and day 6 in PRAME siRNA-treated cells. Increase of p27 protein expression was also confirmed with western blot analysis. Furthermore, PRAME siRNA-treated cells showed a change of erythroid regulatory genes. Our result observed an increase in GATA-1 protein from day 3 to day 6, a decrease in GATA-2 protein from day 1 to day 5, and a decrease in PU.1 protein from day 2 to day 6, as well as quantitative real-time RT-PCR. On annexin V assay, the percentage of apoptotic cells gradually increased from day 3 to day 6 in PRAME siRNA-treated cells. The total percentage of apoptotic cells on day 6 was 45.5% (early apoptotic cells 33.1%, late apoptotic/necrotic cells 12.4%) in PRAME siRNA-treated cells and only 10.1% (early apoptosis 8.0%, late apoptosis 2.1%) in control cells. Caspase-3 was activated on day 3 in PRAME siRNA-treated cells, then increased gradually with the maximum activity being observed on day 6 (33.4%) using antibody against cleaved caspase-3 by flow cytometory. Western blot analysis showed that a faint band of cleaved caspase-3 protein was detected after day 3, and then an obviously augmented band was observed on days 5–6. In 51.4% of clinical samples in our study, the PRAME expression level was higher at relapse than at diagnosis. In the group in which PRAME expression was higher at relapse, the percentage of S phase cells at relapse was significantly increased compared to that at diagnosis (median, 2.4% at diagnosis vs. 6.8% at relapse, P = 0.02, n = 18). Conclusions: Inhibition of PRAME by siRNA in K562 cells suggested that PRAME expression is associated with cell cycle progression from the G0/G1 phase to S phase, inhibition of apoptosis and blocking of cell differentiation. Furthermore, we found cell cycle progression in leukemia patients in whom PRAME was highly expressed at relapse. The PRAME gene may be one of the important genes influencing proliferation of leukemic cells. Insights into the function of PRAME are expected to provide a new perspective on characteristics at relapse in acute leukemia, making it an attractive molecular target for potential therapy. Disclosures: No relevant conflicts of interest to declare.

Prima-1Met Combined with Bortezomib Has Synergistic Anti-Myeloma Activity By Modulation of Apoptosis and Cell Cycle Regulating Genes

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4213-4213
Author(s):  
Priya Khoral ◽  
Robert J Guo ◽  
Jahangir Abdi ◽  
Hong Chang
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Western Blot ◽  
Real Time ◽  
Cell Lines ◽  
Blot Analysis ◽  
Drug Combination ◽  
Western Blot Analysis ◽  
Rt Pcr ◽  
Novel Therapeutic

Abstract INTRODUCTION Multiple Myeloma (MM) is a plasma-cell malignancy characterized by dismal prognosis and a high level of relapse, thus novel therapeutic approaches are needed. PRIMA-1Met is a novel small molecule showing anti-tumour activity and currently in clinical phase I-II trials. We recently demonstrated that PRIMA-1Met has potent anti-MM activity in vitro and in vivo. Bortezomib (BTZ) is a proteasome inhibitor that has been successfully used for treating some cases of relapsed MM. The aim of the current study is to determine whether PRIMA-1Met could be used in combination with BTZ to enhance the cytotoxic effects in myeloma cells. METHODS Using three different MM cell lines (LP1, U266 and 8226), we established dose response curves for both PRIMA-1Met and BTZ, and tested drug cytotoxicity using MTT assays. We then tested drug cytotoxicity of a range of concentrations of the drugs in combination. The Chou Talay method was used to determine whether or not the drug combinations were synergistic. A gene expression array was used to investigate the mechanism of the drug combination's effects. Total RNA was isolated from MM cell pellets, then synthesized cDNAs were applied to real time RT-PCR gene expression arrays containing 84 genes of interest. The genes selected were involved in apoptotic as well as cell growth and proliferation pathways. After normalization to 4 different housekeeping genes, fold changes in gene expression were analyzed in both drug treated and control samples using the 2-ΔΔCt algorithm. Western blot analysis was used to further investigate proteins of interest. RESULTS Cell viability of 8226, LP1 and U266 cells treated with individual concentrations of PRIMA-1Met (10uM) and BTZ (10nM) was on average 65%, 45% and 72.5%, respectively. However, combination of above doses reduced viability to 20% in 8226 and LP1, and to 40% in U266. The Chou Talay method identified this drug combination as synergistic in 2 out of the three tested cell lines, with Combination Index (CI) values of 0.72 in 8226 and 0.582 in U266. The gene expression analysis in real time RT-PCR indicated that the drug combination resulted in downregulation of genes involved in cell cycle and proliferation (CCND1, CDK4, CDK6, CDK2, IGFIR), genes from the Bcl-2 family of apoptosis regulation (Bcl-2, Bcl-XL, Mcl-1), as well as MDM2 from the p53 signalling pathway, and MYC, which is involved in both apoptosis and cell cycle progression. Western blot analysis revealed up-regulation of cleaved caspase-3 and -9, implying involvement of the intrinsic apoptotic pathway in the drug combination's activity. CONCLUSION Our results reveal that PRIMA-1Met synergistically enhances the anti-MM effect of BTZ, leading to a significantly higher level of MM cell death. Real time RT-PCR gene array analysis offers some insight into the mechanism of this combination's effect, implicating apoptotic, cell cycle and growth regulating genes. Our study provides framework for further evaluation of this drug combination as a novel therapeutic strategy in MM. Disclosures No relevant conflicts of interest to declare.

Proteasome Inhibitors Can Induce Caspase-3 Activation and Apoptosis in Human CML Cell Lines.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4681-4681
Author(s):  
Byung-Su Kim ◽  
Chang Up Kim ◽  
Young-Ju Kim ◽  
Eun Kyung Bae ◽  
Jinhee Kim ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Western Blot ◽  
Cell Lines ◽  
Blot Analysis ◽  
Proteasome Inhibitor ◽  
Western Blot Analysis ◽  
Caspase 3 ◽  
Expression Patterns ◽  
Proteasome Inhibitors ◽  
Acridine Orange Staining

Abstract The proteasome is a multi-enzyme complex that provides the ubiquitin-dependent degradation of many cytoplasmic and nuclear proteins involved in cell cycle progression and apoptosis. Inhibition of the proteasome represents a promising approach for the treatment of cancer because it can lead to cell cycle arrest and activation of caspases in tumor cells. There are several proteasome inhibitors that have been reported to induce apoptosis in various tumors. However, the effect of proteasome inhibition in human myeloid leukemia has not been reported so far. In this study, we tested two peptide-aldehyde proteasome inhibitors (MG115, MG132) on two human CML cell lines (K562, KCL22). At first, we treated both cell lines for 24, 48 and 72 hours with different doses of MG115 and MG132 and cell viability was tested by MTT assay. It showed substantial time and dose dependent cytotoxicity in both CML cell lines. Acridine orange staining also revealed DNA fragmentation. We then performed caspase-3 colorimetric assay after treating both cell lines for 6, 12 and 24 hours with 0.78μM of MG115, MG132. K562 showed the continuous rising of caspase-3 activity, while KCL22 exhibited the initial increase and subsequent mild decrease of caspase-3 activity. In addition, western blot analysis showed the reduction of procaspase-3 expression. The expression of Bcl-2 and Bcl-XL was reduced by western blot. p21 expression was slightly increased and that of cyclin D1 was decreased. Additionally, the treatment of proteasome inhibitor in CML cell lines initially induced phosphorylation of Jun kinase. We next examined the expression of heat shock proteins (Hsp70, Hsp90) after treating for 6, 12, 24 hours with the same proteasome inhibitors. Western blot analysis results indicated that expression patterns were different between MG115 and MG132. MG115 induced the slight increase of Hsp70 and Hsp90 in K562, but the reduction of both in KCL22. Meanwhile, MG132 produced the decrease of Hsp70 and Hsp90 in both K562, KCL22. In summary, our work supports that a proteasome inhibitor can induce apoptosis in human CML cell lines. We are currently focusing on the combined effect of proteasome inhibitor and Hsp90 inhibitor on CML. IC50 of Proteasome Inhibitors Cell line Proteasome Inhibitor 24hr 48hr 72hr K562 MG115 3.01 μM 1.14 μM 0.59 μM K562 MG132 μ 2.13 M 1.03 μM 0.57 μM KCL22 MG115 156.92 μM 1.36 μM 0.73 μM KCL22 MG132 1.56 μM 0.93 μM μ 0.75 M

scholarly journals Effects of Electroacupuncture on Ovarian Expression of the Androgen Receptor and Connexin 43 in Rats with Letrozole-Induced Polycystic Ovaries

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Ge Xu ◽  
Andong Zhang ◽  
Jiandang Liu ◽  
Xi Wang ◽  
Jiwei Feng ◽  
...  
Keyword(s):  
Androgen Receptor ◽  
Western Blot ◽  
Real Time ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Connexin 43 ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mrna Levels ◽  
Endocrine Dysfunction ◽  
Rt Pcr

Background. Polycystic ovarian syndrome (PCOS) occurs in women of reproductive age and is often characterized by reproductive and endocrine dysfunction. Androgens play a major role in PCOS, and previous studies reported abnormal expression of Connexin 43 (Cx43) in animal models of PCOS, suggesting an association of Cx43 with PCOS pathogenesis. Experimental and clinical evidence indicated that acupuncture may be a safe and effective approach for treating reproductive and endocrine disorders in women with PCOS. This study aimed to determine the effects of electroacupuncture (EA) on PCOS and its relationship with the expression of the androgen receptor (AR) and Cx43. Methods. In total, 30 female Sprague Dawley rats (6 weeks old) were randomly divided into three groups: control group, letrozole (LE) group, and LE + EA group. Rats were administered LE solution (1.0 mg/kg) for 21 consecutive days to induce PCOS. For the LE + EA group, additional EA treatment was conducted (2 Hz, 20 min/d) with “Guanyuan” (CV3) for 14 consecutive days. After hematoxylin-eosin staining, the ovarian structure was observed with an optical microscope, and serum levels of the following hormones were examined via enzyme-linked immunosorbent assay (ELISA): testosterone (T), estradiol (E2), sex hormone-binding globulin (SHBG), follicle-stimulating hormone (FSH); luteinizing hormone (LH), insulin (INS), anti-Müllerian hormone (AMH), and inhibin B (INHB). Fasting blood glucose (FBG) levels were evaluated using glucose oxidase-peroxidase. Ovarian mRNA and protein expressions of AR and Cx43 were determined by real-time RT-PCR and Western blot analysis. Results. EA was found to restore the cyclicity and ovarian morphology in the PCOS rat model. Serum derived from the LE + EA group showed significant decreases in the levels of T, free androgen index (FAI), LH, LH/FSH ratio, AMH, INHB, and fasting serum insulin (FINS), and significant increases in the levels of E2, FSH, and SHBG. Western blot analysis showed a decreased protein expression of ovarian AR and Cx43; real-time RT-PCR showed reduced expression of ovarian mRNA levels of AR and Cx43. Conclusions. In conclusion, our results showed that EA can ease hyperandrogenism and polycystic ovary morphology in PCOS rats. Furthermore, EA counteracted the letrozole-induced upregulation of AR and Cx43. These results suggested that acupuncture can break the vicious cycle initiated by excessive androgen secretion and may be an effective treatment method for improving the reproductive and endocrine dysfunction caused by PCOS.

Cyclin B1, D1 overexpression and its correlation with clinical prognostic factors in ovarian carcinoma

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 15067-15067
Author(s):  
J. W. Kim ◽  
Y. T. Kim ◽  
H. Y. Kim ◽  
M. H. Kang ◽  
J. H. Kim ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Prognostic Factors ◽  
Western Blot ◽  
Ovarian Carcinoma ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Cyclin B1 ◽  
Rt Pcr ◽  
The Mean ◽  
The Relationship

15067 Background: The change of cell cycle is one of the characteristics of cancer. The various proteins related to the cell cycle have been revealed and their expression in ovarian carcinoma has been demonstrated. Therefore, this study was conducted to determine the expression of cyclin B1, D1 and evaluate the relationship between cyclin B1, D1 and clinical prognostic factors in patients with ovarian carcinoma. Methods: 41 fresh ovarian tissue samples including 36 ovarian carcinomas and 5 normal ovarian tissues were surgically obtained at YUMC from May 2002 to February 2005. Cyclin B1, D1 expression were detected using the quantitative real-time RT-PCR and Western blot analysis. For clinical prognostic factors, age, stage, grade, histopathology, LN metastasis, residual tumor size, CA 125 and DNA flow cytometry were evaluated. Results: By quantitative real time RT-PCR, the mean 2−ΔΔCT value of cyclin B1 and D1 mRNA in ovarian carcinoma was 5.83 ± 12.03, 17.60 ± 22.20, slightly higher than that of the control. (p = 0.67, 0.07). The mean value of relative protein levels of cyclin B1 and D1 in Western blot analysis was also higher in ovarian carcinoma (1.30 ± 0.73, 1.81 ± 1.28, respectively) (p = 0.76, 0.06). No significant relationship of cyclin B1, D1 expression and clinical prognostic factors was observed. Conclusions: The expression of cyclin B1, D1 in ovarian carcinoma was higher than that of the control, although there was no statistical significance. This suggests that cyclin B1, D1 might be involved in the tumorigenesis and the progression of malignancy. Even though there was no significant correlation between cyclin expression and prognostic factors, further studies are needed assessing the relationship between cyclin expression and survival rate to elucidate the role of cyclin as a prognostic factor in ovarian carcinoma. No significant financial relationships to disclose.

scholarly journals DIAPH1 Is Upregulated and Inhibits Cell Apoptosis through ATR/p53/Caspase-3 Signaling Pathway in Laryngeal Squamous Cell Carcinoma

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Jiechao Yang ◽  
Liang Zhou ◽  
Yanping Zhang ◽  
Juan Zheng ◽  
Jian Zhou ◽  
...  
Keyword(s):  
Squamous Cell Carcinoma ◽  
Western Blot ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Molecular Mechanisms ◽  
Caspase 3 ◽  
Laryngeal Squamous Cell Carcinoma ◽  
Poor Overall Survival

Cancer bioinformatics has been used to screen possible key cancer genes and pathways. Here, through bioinformatics analysis, we found that high expression of diaphanous related formin 1 (DIAPH1) was associated with poor overall survival in head and neck squamous cell carcinoma and laryngeal squamous cell carcinoma (LSCC). The effect of DIAPH1 in LSCC has not been previously investigated. Therefore, we evaluated the expression, function, and molecular mechanisms of DIAPH1 in LSCC. Immunohistochemistry and western blot analysis confirmed the significant upregulation of DIAPH1 in LSCC. We used DIAPH1 RNA interference to construct two DIAPH1-knockdown LSCC cell lines, AMC-HN-8 and FD-LSC-1, and validated the knockdown efficiency. Flow cytometry data showed that DIAPH1 inhibited apoptosis. Further, western blot analysis revealed that DIAPH1 knockdown increased the protein levels of ATR, p-p53, Bax, and cleaved caspase-3, -8, and -9. Thus, DIAPH1 is upregulated in LSCC and may act as an oncogene by inhibiting apoptosis through the ATR/p53/caspase-3 pathway in LSCC cells.

scholarly journals NHE1, NHE2, and NHE3 contribute to regulation of intracellular pH in murine duodenal epithelial cells

2000 ◽  
Vol 278 (2) ◽  
pp. G197-G206 ◽  
Author(s):  
J. Praetorius ◽  
D. Andreasen ◽  
B. L. Jensen ◽  
M. A. Ainsworth ◽  
U. G. Friis ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Western Blot ◽  
Intracellular Ph ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Mrna Level ◽  
Rt Pcr ◽  
Acid Extrusion ◽  
Molecular Expression ◽  
Nhe Isoforms

Na+/H+-exchangers (NHE) mediate acid extrusion from duodenal epithelial cells, but the isoforms involved have not previously been determined. Thus we investigated 1) the contribution of Na+-dependent processes to acid extrusion, 2) sensitivity to Na+/H+ exchange inhibitors, and 3) molecular expression of NHE isoforms. By fluorescence spectroscopy the recovery of intracellular pH (pHi) was measured on suspensions of isolated acidified murine duodenal epithelial cells loaded with 2′,7′-bis(2-carboxyethyl)-5(6)-carboxyfluorescein. Expression of NHE isoforms was studied by RT-PCR and Western blot analysis. Reduction of extracellular Na+ concentration ([Na+]o) during pHirecovery decreased H+ efflux to minimally 12.5% of control with a relatively high apparent Michaelis constant for extracellular Na+. The Na+/H+exchange inhibitors ethylisopropylamiloride and amiloride inhibited H+ efflux maximally by 57 and 80%, respectively. NHE1, NHE2, and NHE3 were expressed at the mRNA level (RT-PCR) as well as at the protein level (Western blot analysis). On the basis of the effects of low [Na+]o and inhibitors we propose that acid extrusion in duodenal epithelial cells involves Na+/H+ exchange by isoforms NHE1, NHE2, and NHE3.

scholarly journals Integrin β3 Mediates the Endothelial-to-Mesenchymal Transition via the Notch Pathway

2018 ◽  
Vol 49 (3) ◽  
pp. 985-997 ◽  
Author(s):  
Weisen Wang ◽  
Zhi Wang ◽  
Dingyuan Tian ◽  
Xi Zeng ◽  
Yangdong Liu ◽  
...  
Keyword(s):  
Western Blot ◽  
Notch Signaling ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Notch Signaling Pathway ◽  
Rt Pcr ◽  
Mesenchymal Transition ◽  
Integrin Β3 ◽  
Endothelial To Mesenchymal Transition ◽  
Tgf Β1

Background/Aims: Neointimal hyperplasia is responsible for stenosis, which requires corrective vascular surgery, and is also a major morphological feature of many cardiovascular diseases. This hyperplasia involves the endothelial-to-mesenchymal transition (EndMT). We investigated whether integrin β3 can modulate the EndMT, as well as its underlying mechanism. Methods: Integrin β3 was overexpressed or knocked down in human umbilical vein endothelial cells (HUVECs). The expression of endothelial markers and mesenchymal markers was determined by real-time reverse transcription PCR (RT-PCR), immunofluorescence staining, and western blot analysis. Notch signaling pathway components were detected by real-time RT-PCR and western blot analysis. Cell mobility was evaluated by wound-healing, Transwell, and spreading assays. Fibroblast-specific protein 1 (FSP-1) promoter activity was determined by luciferase assay. Results: Transforming growth factor (TGF)-β1 treatment or integrin β3 overexpression significantly promoted the EndMT by downregulating VE-cadherin and CD31 and upregulating smooth muscle actin α and FSP-1 in HUVECs, and by enhancing cell migration. Knockdown of integrin β3 reversed these effects. Notch signaling was activated after TGF-β1 treatment of HUVECs. Knockdown of integrin β3 suppressed TGF-β1-induced Notch activation and expression of the Notch downstream target FSP-1. Conclusion: Integrin β3 may promote the EndMT in HUVECs through activation of the Notch signaling pathway.

Abstract 255: Cytoprotective Effects of Erythropoietin and Erythropoietin-derivatives in Ischaemic Human Myotubes and the Role of Pi3k/akt Signalling Pathway

2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Rebekah Sian Hwee Yu ◽  
Daryll Baker ◽  
David Abraham ◽  
Janice Tsui
Keyword(s):  
Skeletal Muscle ◽  
Western Blot ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Caspase 3 ◽  
Signalling Pathway ◽  
Critical Limb Ischaemia ◽  
Human Myotubes ◽  
Muscle Biopsies

Objectives Erythropoietin (Epo) has tissue-protective effects in response to injury, acting through the EpoR-βcR heteroreceptor. We have previously demonstrated the presence and interaction of the EpoR and βcR in human skeletal muscle. Here we aim to investigate the potential cytoprotective effects of Epo and an Epo-derivative (ARA-290) in a human in vitro model of skeletal muscle and establish a potential downstream signalling pathway utilised in protecting cells from apoptosis (including Jak-2, PI3k/Akt, NFkB). Methods Gastrocnemius muscle biopsies were obtained from patients with critical limb ischaemia and control samples were obtained from non-ischaemic patients. Human myoblasts were isolated from muscle biopsies, cultured, and allowed to differentiate into myotubes in order to investigate the cytoprotective effects of Epo and ARA-290 on myotubes subjected to simulated ischaemia. The PI3k inhibitors, LY294002 and wortmannin, were then used to determine the role of PI3k/Akt pathway in mediating cytoprotection. Following this, inhibitors against the upstreatm (Jak-2) and downstream (NFkB) molecules were also investigated. Western blot analysis, using the pro-apoptotic marker cleaved caspase-3 was performed and compared with levels of Akt and phosphorylated-Akt, using western blot analysis. Results Exogenous administration of Epo and ARA-290 were able to ameliorate the ischaemia-induced apoptosis on isolated human myotubes as shown by a significant reduction in cleaved caspase-3 expression. Addition of all inhibitors, to ARA-290 or Epo pre-treated cells, abolished the reduction in apoptosis. Conclusion The ability of ARA-290 to attenuate apoptosis in human myotubes undergoing ischaemic insult suggests a potential role in tissue protection in skeletal muscle injury. We propose that the PI3k/Akt signalling pathway is involved in mediating this cytoprotection.

Interfering With Hyaluronic Acid Metabolism Suppresses Glioma Cell Proliferation by Regulating Autophagy

2020 ◽  
Author(s):  
Tao Yan ◽  
Xin Chen ◽  
Hua Zhan ◽  
Penglei Yao ◽  
Ning Wang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Hyaluronic Acid ◽  
Tumor Microenvironment ◽  
Western Blot ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Glioma Cell ◽  
Glioma Cells

Abstract BackgroundThe tumor microenvironment plays an important role in tumor progression. Hyaluronic acid (HA), an important component of the extracellular matrix in the tumor microenvironment, abnormally accumulates in a variety of tumors. Whereas the role of abnormal HA metabolism in glioma remains unclear. MethodsThe expression level of hyaluronic acid (HA) was analyzed by ELISA assay and proteins such as HAS3, CD44, P62, LC3, CCND1 and CCNB1 were measured with Western blot analysis. The cell viability and proliferation were measured by MTT and KI67 immunofluorescence staining respectively. Autophagic vesicles and autophagosomes were quantified by transmission electron microscopy (TEM) and GFP-RFP-LC3 fluorescence analysis respectively. Cell cycle was analyzed by flowcytometry and Western blot analysis. Immunohistochemical (IHC) staining was used to detect expression levels of HA, Ki67, HAS3 and CD44 in human and mouse tumor tissues. Lentivirus constructed HAS3 and CD44 knockout stable glioma cells were transplanted to BALB/C nude mice for in vivo experiments. 4-Methylumbelliferone (4MU) was also used to treat glioma bearing mice for verifing its anti-tumor ability. The expression curve of HAS3, CD44 and the disease-free survival (DFS) curves for HAS3, CD44 in patients with LGG and GBM was performed based on TCGA database. ResultsAs shown in the present study, HA, hyaluronic acid synthase 3 (HAS3) and a receptor of HA named CD44 are expressed at high levels in human glioma tissues and negatively correlated with the prognosis of patients with glioma. Silencing HAS3 or blocking CD44 inhibited the proliferation of glioma cells in vitro and in vivo. The underlying mechanism was attributed to the inhibition of autophagy flux and further maintaining glioma cell cycle arrest in G1 phase. More importantly, 4-Methylumbelliferone (4-MU), a small competitive inhibitor of UDP with the ability to penetrate the blood-brain barrier (BBB), also inhibited the proliferation of glioma cells in vitro and in vivo. ConclusionApproaches that interfere with HA metabolism by altering the expression of HAS3 and CD44 and the administration of 4-MU potentially represent effective strategies for glioma treatment.

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