scholarly journals BIOM-55. DGKζ-TARGETED REGULATION OF MIR-34A IN THE PROLIFERATION AND TUMORIGENICITY OF HUMAN GLIOBLASTOMA

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii13-ii13
Author(s):  
Wangxian Gu ◽  
Guoqing Wan ◽  
Yanjun Zheng ◽  
Xintong Yang ◽  
Peng Zhang ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Precancerous Lesions ◽  
Lipid Kinase ◽  
Human Glioblastoma ◽  
Kinase Substrate ◽  
Downstream Target ◽  
Protein Levels ◽  
Type Iv

Abstract Diacylglycerol kinase (DGK) is a lipid kinase that catalyzes the phosphorylation of diacylglycerol (DAG) to produce phosphatidic acid (PA), which uses ATP as a phosphate donor. Diacylglycerol kinases ζ(DGKζ) is characterized as specific type IV due to its myristoylated alanine-rich C-kinase substrate (MARCKS), ankyrin, and PDZ binding domain. Similar to other DGKs, DGKζ is also reported to be abnormally expressed in human colorectal cancer cells, and it is indispensable for the proliferation of cancer cells. However, its implications in human glioblastoma (GBM) is largely unknown. Both the mRNA and protein levels of DGKζ were significantly higher in GBM tissues than in precancerous lesions. Knockdown of DGKζ inhibited GBM cell proliferation, cell cycle and promoted apoptosis of GBM cells. Moreover, down-regulation of DGKζ markedly reduced in vitro colony formation and in vivo tumorigenic capability. Furthermore, we confirmed that DGKζ was the downstream target of miR-34a. The expression level of DGKζ was negatively correlated with miR-34a in GBM tissues. Overexpression of DGKζ reversed the tumor suppressive roles of miR-34a in GBM cells. Taken together, DGKζ can act as a potential prognostic biomarker for GBM patients and promote the growth of GBM cells was regulated by miR-34a, and it may represent a promising therapeutic target for patients with GBM.

scholarly journals Long noncoding RNA SNHG14 promotes hepatocellular carcinoma progression by regulating miR-876-5p/SSR2 axis

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Zhibin Liao ◽  
Hongwei Zhang ◽  
Chen Su ◽  
Furong Liu ◽  
Yachong Liu ◽  
...  
Keyword(s):  
Noncoding Rna ◽  
Animal Experiments ◽  
Luciferase Reporter ◽  
Western Blot Assay ◽  
Downstream Target ◽  
Protein Levels ◽  
Elevated Expression ◽  
Rna Immunoprecipitation

Abstract Background Aberrant expressions of long noncoding RNAs (lncRNAs) have been demonstrated to be related to the progress of HCC. The mechanisms that SNHG14 has participated in the development of HCC are obscure. Methods Quantitative real-time PCR (qRT-PCR) was used to measure the lncRNA, microRNA and mRNA expression level. Cell migration, invasion and proliferation ability were evaluated by transwell and CCK8 assays. The ceRNA regulatory mechanism of SNHG14 was evaluated by RNA immunoprecipitation (RIP) and dual luciferase reporter assay. Tumorigenesis mouse model was used to explore the roles of miR-876-5p in vivo. The protein levels of SSR2 were measured by western blot assay. Results In this study, we demonstrated that SNHG14 was highly expressed in HCC tissues, meanwhile, the elevated expression of SNHG14 predicted poor prognosis in patients with HCC. SNHG14 promoted proliferation and metastasis of HCC cells. We further revealed that SNHG14 functioned as a competing endogenous RNA (ceRNA) for miR-876-5p and that SSR2 was a downstream target of miR-876-5p in HCC. Transwell, CCK8 and animal experiments exhibited miR-876-5p inhibited HCC progression in vitro and in vivo. By conducting rescue experiments, we found the overexpression of SSR2 or knocking down the level of miR-876-5p could reverse the suppressive roles of SNHG14 depletion in HCC. Conclusion SNHG14 promotes HCC progress by acting as a sponge of miR-876-5p to regulate the expression of SSR2 in HCC.

scholarly journals HOTAIR contributes to cell proliferation and metastasis of cervical cancer via targetting miR-23b/MAPK1 axis

2018 ◽  
Vol 38 (1) ◽  
Author(s):  
Qin Li ◽  
Yanhong Feng ◽  
Xu Chao ◽  
Shuai Shi ◽  
Man Liang ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Cell Proliferation ◽  
Cancer Cells ◽  
Mitogen Activated Protein Kinase ◽  
Cancer Tissue ◽  
Tissue Samples ◽  
Downstream Target ◽  
Cervical Cancer Cells

The long non-coding RNA (lncRNA) HOX transcript antisense RNA (HOTAIR) has been found to be overexpressed in many human malignancies and involved in tumor progression and metastasis. Although the downstream target through which HOTAIR modulates tumor metastasis is not well-known, evidence suggests that miR-23b might be involved in this event. In the present study, the expressions of HOTAIR and miR-23b were detected by real-time PCR in 33 paired cervical cancer tissue samples and cervical cell lines. The effects of HOTAIR on the expressions of miR-23b and mitogen-activated protein kinase 1 (MAPK1) were studied by overexpression and RNAi approaches. We found that HOTAIR expression was significantly increased in cervical cancer cells and tissues. In contrast, the expression of miR-23b was obviously decreased. We further demonstrated that HOTAIR knockdown promoted apoptosis and inhibited cell proliferation and invasion in vitro and in vivo. Moreover, our data indicated that HOTAIR may competitively bind miR-23b and modulate the expression of MAPK1 indirectly in cervical cancer cells. Taken together, our study has identified a novel pathway through which HOTAIR exerts its oncogenic role, and provided a molecular basis for potential applications of HOTAIR in the prognosis and treatment of cervical cancer.

scholarly journals Metadherin enhances vulnerability of cancer cells to ferroptosis

2019 ◽  
Vol 10 (10) ◽  
Author(s):  
Jianling Bi ◽  
Shujie Yang ◽  
Long Li ◽  
Qun Dai ◽  
Nicholas Borcherding ◽  
...  
Keyword(s):  
Cancer Therapy ◽  
Cancer Cells ◽  
Messenger Rna ◽  
Underlying Mechanism ◽  
Lipid Hydroperoxides ◽  
Protein Levels ◽  
Enhanced Sensitivity ◽  
Regulated Cell Death

Abstract Ferroptosis is an iron-dependent, non-apoptotic form of regulated cell death driven by lipid hydroperoxides within biological membranes. Although therapy-resistant mesenchymal-high cancers are particularly vulnerable to ferroptosis inducers, especially phospholipid glutathione peroxidase 4 (GPx4) inhibitors, the underlying mechanism is yet to be deciphered. As such, the full application of GPx4 inhibitors in cancer therapy remains challenging. Here we demonstrate that metadherin (MTDH) confers a therapy-resistant mesenchymal-high cell state and enhanced sensitivity to inducers of ferroptosis. Mechanistically, MTDH inhibited GPx4, as well as the solute carrier family 3 member 2 (SLC3A2, a system Xc− heterodimerization partner), at both the messenger RNA and protein levels. Our metabolomic studies demonstrated that MTDH reduced intracellular cysteine, but increased glutamate levels, ultimately decreasing levels of glutathione and setting the stage for increased vulnerability to ferroptosis. Finally, we observed an enhanced antitumor effect when we combined various ferroptosis inducers both in vitro and in vivo; the level of MTDH correlated with the ferroptotic effect. We have demonstrated for the first time that MTDH enhances the vulnerability of cancer cells to ferroptosis and may serve as a therapeutic biomarker for future ferroptosis-centered cancer therapy.

scholarly journals LncRNA CTD-3252C9.4 modulates pancreatic cancer cell survival and apoptosis through regulating IFI6 transcription

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xin Yin ◽  
Jingyan Yang ◽  
Jintian Chen ◽  
Ruiqi Ni ◽  
Yanhao Zhou ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Pancreatic Cancer Cell ◽  
Luciferase Reporter ◽  
Downstream Target ◽  
Pancreatic Cancer Cells ◽  
Cancer Cell Survival

Abstract Background Pancreatic cancer (PC) is one of the most lethal cancer types with high degree of malignancy and poor prognosis. Recent studies have shown that long non-coding RNAs (lncRNAs) were associated with the initiation and progression of pancreatic cancer. In the current study, we have investigated the expression, biological function and mechanism of a lncRNA CTD-3252C9.4 in pancreatic cancer. Methods The expression of CTD-3252C9.4 in pancreatic cancer cells and tissues was measured by qRT-PCR. In vitro and in vivo functional experiments assays were implemented for identifying CTD-3252C9.4 function in pancreatic cancer. Molecular relationships among CTD-3252C9.4, IRF1 and IFI6 were investigated via luciferase reporter assay, pulldown assay and ChIP assays. Results CTD-3252C9.4 was found remarkably decreased in pancreatic cancer cells and tissues. Overexpression of CTD-3252C9.4 suppressed migration, invasion and proliferation, yet facilitated apoptosis of pancreatic cancer cells both in vitro and in vivo. Then, IFI6 was identified as a downstream target that could be down-regulated by CTD-3252C9.4 and IFI6 overexpression could counteract the effects of CTD-3252C9.4 upregulation on the survival and apoptosis of pancreatic cancer cells. Furthermore, mechanism experiments revealed that IRF1 was a transcriptional factor of IFI6 that can be blocked by CTD-3252C9.4 to inhibit IFI6 transcription. Conclusion Our data indicated that CTD-3252C9.4 could promote pancreatic cancer cell apoptosis and restrain cell growth via binding IRF1 and preventing the transcription of IFI6, which may become a potential therapeutic target for pancreatic cancer.

scholarly journals Exosomal miR-27a Derived from Gastric Cancer Cells Regulates the Transformation of Fibroblasts into Cancer-Associated Fibroblasts

2018 ◽  
Vol 49 (3) ◽  
pp. 869-883 ◽  
Author(s):  
Jingya Wang ◽  
Xuwen Guan ◽  
Yue Zhang ◽  
Shaohua Ge ◽  
Le Zhang ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cancer Cells ◽  
Biological Behavior ◽  
Transport Systems ◽  
Cancer Associated Fibroblasts ◽  
Gastric Cancer Cells ◽  
Downstream Target ◽  
Malignant Behavior

Background/Aims: The malignant biological behavior of gastric cancer(GC) is not only determined by cancer cells alone, but also closely regulated by the microenvironment. Fibroblasts represent a large proportion of the components in the tumor microenvironment, and they promote the development of disease. Currently, accumulating evidence suggests that exosomes can function as intercellular transport systems to relay their contents, especially microRNAs(miRNAs). Methods: First, we detected the highly-expressed level of miR-27a in exosomes isolated from gastric cancer cells by qRT-PCR. MiR-27a –over-expressed models in vitro and in vivo were established to investigate the transformation of cancer-associated fibroblasts observed by Western blotting, and the malignant behavior of gastric cancer cells using the methods CCK8 and Transwell. Moreover, the downregulation of CSRP2 in fibroblasts was used to evaluate the promotion of malignancy of gastric cancer using the methods CCK8 and Transwell. Results: In this study, we found a marked high level of miR-27a in exosomes derived from GC cells. miR-27a was found to function an oncogene that not only induced the reprogramming of fibroblasts into cancer-associated fibroblasts(CAFs), but also promoted the proliferation, motility and metastasis of cancer cells in vitro and in vivo. Conversely, CAFs with over-expression of miR-27a could pleiotropically increase the malignant behavior of the GC cells. For the first time, we revealed that CSRP2 is a downstream target of miR-27a. CSRP2 downregulation could increase the proliferation and motility of GC cells. Conclusion: Thus, this report indicates that miR-27a in exosomes derived from GC cells has a crucial impact on the microenvironment and may be used as a potential therapeutic target in the treatment of GC

scholarly journals Primaquine Inhibits the Endosomal Trafficking and Nuclear Localization of EGFR and Induces the Apoptosis of Breast Cancer Cells by Nuclear EGFR/Stat3-Mediated c-Myc Downregulation

2021 ◽  
Vol 22 (23) ◽  
pp. 12961
Author(s):  
Ji-Hyang Kim ◽  
Hack-Sun Choi ◽  
Dong-Sun Lee
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Nuclear Translocation ◽  
Growth Factor Receptor ◽  
Endosomal Trafficking ◽  
Protein Levels ◽  
Early Endosomes

Triple-negative breast cancer (TNBC) cells overexpress the epidermal growth factor receptor (EGFR). Nuclear EGFR (nEGFR) drives resistance to anti-EGFR therapy and is correlated with poor survival in breast cancer. Inhibition of EGFR nuclear translocation may be a reasonable approach for the treatment of TNBC. The anti-malarial drugs chloroquine and primaquine have been shown to promote an anticancer effect. The aim of the present study was to investigate the effect and mechanism of chloroquine- and primaquine-induced apoptosis of breast cancer cells. We showed that primaquine, a malaria drug, inhibits the growth, migration, and colony formation of breast cancer cells in vitro, and inhibits tumor growth in vivo. Primaquine induces damage to early endosomes and inhibits the nuclear translocation of EGFR. Primaquine inhibits the interaction of Stat3 and nEGFR and reduces the transcript and protein levels of c-Myc. Moreover, primaquine and chloroquine induce the apoptosis of breast cancer cells through c-Myc/Bcl-2 downregulation, induce early endosome damage and reduce nEGFR levels, and induce apoptosis in breast cancer through nEGFR/Stat3-dependent c-Myc downregulation. Our study of primaquine and chloroquine provides a rationale for targeting EGFR signaling components in the treatment of breast cancer.

scholarly journals WISP2/CCN5 gene knockdown in vitro and in vivo exhibits proliferation promotion of breast cancer through targeting Skp2 and p27Kip1

2020 ◽  
Author(s):  
Yan Lv ◽  
Chang Zhang ◽  
Xiao Jiang Li ◽  
Shan Gao ◽  
Xu Zheng ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Gene Knockdown ◽  
Control Group ◽  
Rt Pcr ◽  
Protein Levels ◽  
Mcf 7

AbstractBackgroundEmerging evidence has demonstrated that WISP2/CCN5 is critically involved in tumorigenesis. However, the function of WISP2/CCN5 in breast cancer carcinogenesis is largely unclear.Methodswe aim to explore the effects and potential mechanisms of WISP2/CCN5 on proliferation of breast cancer cells and carcinogenesis of breast cancer xenograft. Lentivirus vector with WISP2/CCN5shRNA was transfected into MCF-7, and breast cancer cells and xenograft were conducted. Effect of WISP2/CCN5 on growth and carcinogenesis of breast cancer cells and xenografts was evaluated by MTT assay and tumor volume. The relationship between WISP2/CCN5, Skp2 and p27Kip1 was detected in vitro and in vivo by RT-PCR at mRNA level and Western blotting at protein level.ResultsThe result of MTT assay indicated that MCF-7 cell growth viability in WISP2/CCN5 gene knockdown group was significantly higher than negative vector group(P<0.05) or control group (P<0.05). It suggested that knockdown of WISP2/CCN5 gene by shRNA lentivirus plasmid promoted proliferation of MCF-7 cells. The growth curves of breast cancer xenograft showed that xenografts in WISP2/CCN5 knockdown group grew more quickly than negative vector group(P< 0.05) or control group (P< 0.05). Subsequently, the results of RT-PCR and Western blotting revealed that WISP2/CCN5 gene knockdown led to increased Skp2 and decreased p27Kip1 at mRNA and protein levels. WISP2/CCN5 exerts its inhibition on proliferation of MCF-7 cell line and suppressive functions on growth of breast carcinoma via regulation of Skp2 and p27Kip1at mRNA and protein levels. However, WISP2/CCN5 gene knockdown resulted in loss of inhibition effect on MCF-7 and breast cancer.ConclusionsOur findings suggest that WISP2/CCN5 could be a useful therapeutic strategy for the treatment of breast cancer through targeting Skp2 and p27Kip1.

scholarly journals Methylthioadenosine is Not Dramatically Elevated in MTAP-Homozygous Deleted Primary Glioblastomas

2019 ◽  
Author(s):  
Yasaman Barekatain ◽  
Victoria C. Yan ◽  
Jeffrey J. Ackroyd ◽  
Anton H. Poral ◽  
Theresa Tran ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Stromal Cells ◽  
Homozygous Deletion ◽  
Human Tumors ◽  
Normal Brain ◽  
List Type ◽  
Human Glioblastoma ◽  
Frequent Event

In BriefThe co-deletion of MTAP in the CDKN2A locus is a frequent event in diverse cancers including glioblastoma. Recent publications report that significant accumulations of the MTAP substrate, methylthioadenosine (MTA), can sensitize MTAP-deleted cancer cells to novel inhibitors of PRMT5 and MAT2A for targeted therapy against tumors with this particular genetic alteration. In this work, using comprehensive metabolomic profiling, we show that MTA is primarily secreted, resulting in exceedingly high levels of extracellular MTA in vitro. We further show that primary human glioblastoma tumors minimally accumulate MTA in vivo, which is likely explained by the metabolism of MTA by MTAP-competent stromal cells. Together, these data challenge whether the metabolic conditions required for therapies to exploit vulnerabilities associated MTAP deletions are present in primary human tumors, questioning their translational efficacy in the clinic.HighlightsMethylthioadenosine (MTA) is elevated in MTAP-deleted cancer cells in vitro, which provides a selective vulnerability to PRMT5 and MAT2A inhibitorsAccumulation of MTA in MTAP-deleted cancer cells is predominately extracellular, suggesting active secretion of MTA.MTAP-deleted primary human glioblastoma tumors show minimal intratumoral elevations of MTA, which is likely explained by secretion and metabolism by MTAP-competent stromal cells.SUMMARYHomozygous deletion of the CDK2NA locus frequently results in co-deletion of methylthioadenosine phosphorylase (MTAP) in many fatal cancers such as glioblastoma multiforme (GBM), resulting in elevations of the substrate metabolite, methylthioadenosine (MTA). To capitalize on such accumulations, therapeutic targeting of protein arginine methyltransferase 5 (PRMT5) and methionine adenosyl transferase (MAT2A) are ongoing. While extensively corroborated in vitro, the clinical efficacy of these strategies ultimately relies on equally significant accumulations of MTA in human tumors. Here, we show that in vitro accumulation of MTA is a predominately extracellular phenomenon, indicating secretion of MTA from MTAP-deleted cells. In primary human GBMs, we find that MTA levels are not significantly higher in MTAP-deleted compared to MTAP-intact tumors or normal brain tissue. Together, these findings highlight the metabolic discrepancies between in vitro models and primary human tumors and should thus be carefully considered in the development of the precision therapies targeting MTAP-homozygous deleted GBM.

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