Targeting of human cancers by miRNAs delivered by mesenchymal stem cell derived microparticles.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e14062-e14062
Author(s):  
Agamemnon A. Epenetos ◽  
Marianna Prokopi ◽  
Costas Pitsillides
Keyword(s):  
Tumor Suppressor ◽  
Cancer Cells ◽  
Kinase Activity ◽  
Imaging Techniques ◽  
Ectopic Expression ◽  
Protein Kinase Activity ◽  
Cancer Disease ◽  
Human Cancers ◽  
Target Cancer

e14062 Background: Recent data has shown that several oncogenic and tumor suppressor kinases that are deregulated in human cancers can be targeted via specific miRNA sequences. miRNAs can inhibit oncogenic kinase activity as well as upregulate tumor suppressor kinases in cancer cells, leading to inhibition of tumor processes such as invasion, migration and resistance to apoptosis. Examples include the inhibition of PLK1 activity that is overexpressed in breast, ovarian, pancreatic and colorectal cancers by the ectopic expression of miR-10b, miR-100 or miR-593, and the targeting of the increased FAK expression in breast cancer cells by miR-7. Methods: In this study, we have employed preclinical models of cancer disease and have utilized advanced genomics technologies in combination with innovative in vivo imaging techniques to conduct pharmacokinetics and pharmacodynamics studies as well as safety and efficacy studies in order to establish a mechanism of action and demonstrate that miRNA-loaded microparticles can interfere with tumor promoting kinase activity in vivo Results: Our results demonstrate that delivering specific miRNAs targeted against aberrant protein kinase activity may potentially be a novel approach to selectively inhibit cancer cell processes. Conclusions: We report the development of a new microRNA-based approach to target cancer cells by potentially interfering in multiple signaling pathways that are mediated by kinase-dependent mechanisms. We propose that therapeutic miRNA sequences can be delivered to cancer cells via microparticles (MPs) derived from umbilical cord mesenchymal stem cells (MSCs). The engineered MPs home selectively to tumor sites via specific chemokine receptors, fuse with the cell membrane and incorporate miRNA directly into the target cancer cells.

scholarly journals Hypermethylation of DHRS3 as a Novel Tumor Suppressor Involved in Tumor Growth and Prognosis in Gastric Cancer

2021 ◽  
Vol 9 ◽  
Author(s):  
Sha Sumei ◽  
Kong Xiangyun ◽  
Chen Fenrong ◽  
Sun Xueguang ◽  
Hu Sijun ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Tumor Suppressor ◽  
Tumor Growth ◽  
Human Cancer ◽  
Methylation Status ◽  
Ectopic Expression ◽  
Survival Times

Background/AimsThe role of DHRS3 in human cancer remains unclear. Our study explored the role of DHRS3 in gastric cancer (GC) and its clinicopathological significance and associated mechanisms.MaterialsBisulfite-assisted genomic sequencing PCR and a Mass-Array system were used to evaluate and quantify the methylation levels of the promoter. The expression levels and biological function of DHRS3 was examined by both in vitro and in vivo assays. A two-way hierarchical cluster analysis was used to classify the methylation profiles, and the correlation between the methylation status of the DHRS3 promoter and the clinicopathological characteristics of GC were then assessed.ResultsThe DHRS3 promoter was hypermethylated in GC samples, while the mRNA and protein levels of DHRS3 were significantly downregulated. Ectopic expression of DHRS3 in GC cells inhibited cell proliferation and migration in vitro, decreased tumor growth in vivo. DHRS3 methylation was correlated with histological type and poor differentiation of tumors. GC patients with high degrees of CpG 9.10 methylation had shorter survival times than those with lower methylation.ConclusionDHRS3 was hypermethylated and downregulated in GC patients. Reduced expression of DHRS3 is implicated in gastric carcinogenesis, which suggests DHRS3 is a tumor suppressor.

scholarly journals RUNX1 suppresses breast cancer stemness and tumor growth

2018 ◽  
Author(s):  
Deli Hong ◽  
Andrew J. Fritz ◽  
Kristiaan H. Finstad ◽  
Mark P. Fitzgerald ◽  
Adam L. Viens ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Stem Cell ◽  
Tumor Suppressor ◽  
Cancer Stem Cell ◽  
Tumor Growth ◽  
Epithelial Mesenchymal Transition ◽  
Ectopic Expression ◽  
Cell Activity ◽  
Mesenchymal Transition

SummaryRecent studies have revealed that mutations in the transcription factor Runx1 are prevalent in breast tumors. Yet, how loss of Runx1 contributes to breast cancer (BCa) remains unresolved. We demonstrate for the first time that Runx1 represses the breast cancer stem cell (BCSC) phenotype and consequently, functions as a tumor suppressor in breast cancer. Runx1 ectopic expression in MCF10AT1 and MCF10CA1a BCa cells reduces (60%) migration, invasion and in vivo tumor growth in mouse mammary fat pad (P<0.05). Runx1 is decreased in BCSCs, and overexpression of Runx1 suppresses tumorsphere formation and reduces the BCSC population. Furthermore, Runx1 inhibits Zeb1 expression, while Runx1 depletion activates Zeb1 and the epithelial-mesenchymal transition. Mechanistically Runx1 functions as a tumor suppressor in breast cancer through repression of cancer stem cell activity. This key regulation of BCSCs by Runx1 may be shared in other epithelial carcinomas, highlighting the importance of Runx1 in solid tumors.

scholarly journals The protein kinase activity of fructokinase A specifies the antioxidant responses of tumor cells by phosphorylating p62

2019 ◽  
Vol 5 (4) ◽  
pp. eaav4570 ◽  
Author(s):  
Daqian Xu ◽  
Xinjian Li ◽  
Fei Shao ◽  
Guishuai Lv ◽  
Hongwei Lv ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Protein Kinase ◽  
Cancer Cells ◽  
Kinase Activity ◽  
Survival Rates ◽  
Adenosine Monophosphate ◽  
Nuclear Accumulation ◽  
Protein Kinase Activity ◽  
Reduction Cell ◽  
Expression Of Genes

Cancer cells often encounter oxidative stress. However, it is unclear whether normal and cancer cells differentially respond to oxidative stress. Here, we demonstrated that under oxidative stress, hepatocellular carcinoma (HCC) cells exhibit increased antioxidative response and survival rates compared to normal hepatocytes. Oxidative stimulation induces HCC-specifically expressed fructokinase A (KHK-A) phosphorylation at S80 by 5′-adenosine monophosphate-activated protein kinase. KHK-A in turn acts as a protein kinase to phosphorylate p62 at S28, thereby blocking p62 ubiquitination and enhancing p62’s aggregation with Keap1 and Nrf2 activation. Activated Nrf2 promotes expression of genes involved in reactive oxygen species reduction, cell survival, and HCC development in mice. In addition, phosphorylation of KHK-A S80 and p62 S28 and nuclear accumulation of Nrf2 are positively correlated in human HCC specimens and with poor prognosis of patients with HCC. These findings underscore the role of the protein kinase activity of KHK-A in antioxidative stress and HCC development.

scholarly journals Mortaparib, a novel dual inhibitor of mortalin and PARP1, is a potential drug candidate for ovarian and cervical cancers

2019 ◽  
Vol 38 (1) ◽  
Author(s):  
Jayarani F. Putri ◽  
Priyanshu Bhargava ◽  
Jaspreet Kaur Dhanjal ◽  
Tomoko Yaguchi ◽  
Durai Sundar ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Growth Arrest ◽  
Suppressor Activity ◽  
Dual Inhibitor ◽  
Tumor Suppressor Activity ◽  
And Migration

Abstract Background Mortalin is enriched in a large variety of cancers and has been shown to contribute to proliferation and migration of cancer cells in multiple ways. It has been shown to bind to p53 protein in cell cytoplasm and nucleus causing inactivation of its tumor suppressor activity in cancer cells. Several other activities of mortalin including mitochondrial biogenesis, ATP production, chaperoning, anti-apoptosis contribute to pro-proliferative and migration characteristics of cancer cells. Mortalin-compromised cancer cells have been shown to undergo apoptosis in in vitro and in vivo implying that it could be a potential target for cancer therapy. Methods We implemented a screening of a chemical library for compounds with potential to abrogate cancer cell specific mortalin-p53 interactions, and identified a new compound (named it as Mortaparib) that caused nuclear enrichment of p53 and shift in mortalin from perinuclear (typical of cancer cells) to pancytoplasmic (typical of normal cells). Biochemical and molecular assays were used to demonstrate the effect of Mortaparib on mortalin, p53 and PARP1 activities. Results Molecular homology search revealed that Mortaparib is a novel compound that showed strong cytotoxicity to ovarian, cervical and breast cancer cells. Bioinformatics analysis revealed that although Mortaparib could interact with mortalin, its binding with p53 interaction site was not stable. Instead, it caused transcriptional repression of mortalin leading to activation of p53 and growth arrest/apoptosis of cancer cells. By extensive computational and experimental analyses, we demonstrate that Mortaparib is a dual inhibitor of mortalin and PARP1. It targets mortalin, PARP1 and mortalin-PARP1 interactions leading to inactivation of PARP1 that triggers growth arrest/apoptosis signaling. Consistent with the role of mortalin and PARP1 in cancer cell migration, metastasis and angiogenesis, Mortaparib-treated cells showed inhibition of these phenotypes. In vivo tumor suppression assays showed that Mortaparib is a potent tumor suppressor small molecule and awaits clinical trials. Conclusion These findings report (i) the discovery of Mortaparib as a first dual inhibitor of mortalin and PARP1 (both frequently enriched in cancers), (ii) its molecular mechanism of action, and (iii) in vitro and in vivo tumor suppressor activity that emphasize its potential as an anticancer drug.

scholarly journals Comparison of the kinetic properties of the lipid- and protein-kinase activities of the p110α and p110β catalytic subunits of class-Ia phosphoinositide 3-kinases

2000 ◽  
Vol 350 (2) ◽  
pp. 353-359 ◽  
Author(s):  
Carolyn A. BEETON ◽  
Edwin M. CHANCE ◽  
Lazaros C. FOUKAS ◽  
Peter R. SHEPHERD
Keyword(s):  
Protein Kinase ◽  
Kinase Activity ◽  
Membrane Lipid ◽  
Kinetic Properties ◽  
Protein Kinase Activity ◽  
Lipid Kinase ◽  
Functional Roles ◽  
Wide Range ◽  
High Concentrations

Growth factors regulate a wide range of cellular processes via activation of the class-Ia phosphoinositide 3-kinases (PI 3-kinases). We directly compared kinetic properties of lipid- and protein-kinase activities of the widely expressed p110α and p110β isoforms. The lipid-kinase activity did not display Michaelis–Menten kinetics but modelling the kinetic data demonstrated that p110α has a higher Vmax and a 25-fold higher Km for PtdIns than p110β. A similar situation occurs with PtdIns(4,5)P2, because at low concentration of PtdIns(4,5)P2 p110β is a better PtdIns(4,5)P2 kinase than p110α, although this is reversed at high concentrations. These differences suggest different functional roles and we hypothesize that p110β functions better in areas of membranes containing low levels of substrate whereas p110α would work best in areas of high substrate density such as membrane lipid rafts. We also compared protein-kinase activities. We found that p110β phosphorylated p85 to a lower degree than did p110α. We used a novel peptide-based assay to compare the kinetics of the protein-kinase activities of p110α and p110β. These studies revealed that, like the lipid-kinase activity, the protein-kinase activity of p110α has a higher Km (550µM) than p110β (Km 8µM). Similarly, the relative Vmax towards peptide substrate of p110α was three times higher than that of p110β. This implies differences in the rates of regulatory autophosphorylation in vivo, which are likely to mean differential regulation of the lipid-kinase activities of p110α and p110β in vivo.

scholarly journals Branched-chain amino acid aminotransferase 2 regulates ferroptotic cell death in cancer cells

2020 ◽  
Author(s):  
Kang Wang ◽  
Zhengyang Zhang ◽  
Hsiang-i Tsai ◽  
Yanfang Liu ◽  
Jie Gao ◽  
...  
Keyword(s):  
Cell Death ◽  
Amino Acid ◽  
Cancer Cells ◽  
Ectopic Expression ◽  
Branched Chain Amino Acid ◽  
Pancreatic Cancer Cells ◽  
Key Enzyme ◽  
Branched Chain

Abstract Ferroptosis, a form of iron-dependent cell death driven by cellular metabolism and iron-dependent lipid peroxidation, has been implicated as a tumor-suppressor function for cancer therapy. Recent advance revealed that the sensitivity to ferroptosis is tightly linked to numerous biological processes, including metabolism of amino acid and the biosynthesis of glutathione. Here, by using a high-throughput CRISPR/Cas9-based genetic screen in HepG2 hepatocellular carcinoma cells to search for metabolic proteins inhibiting ferroptosis, we identified a branched-chain amino acid aminotransferase 2 (BCAT2) as a novel suppressor of ferroptosis. Mechanistically, ferroptosis inducers (erastin, sorafenib, and sulfasalazine) activated AMPK/SREBP1 signaling pathway through iron-dependent ferritinophagy, which in turn inhibited BCAT2 transcription. We further confirmed that BCAT2 as the key enzyme mediating the metabolism of sulfur amino acid, regulated intracellular glutamate level, whose activation by ectopic expression specifically antagonize system Xc– inhibition and protected liver and pancreatic cancer cells from ferroptosis in vitro and in vivo. On the contrary, direct inhibition of BCAT2 by RNA interference, or indirect inhibition by blocking system Xc– activity, triggers ferroptosis. Finally, our results demonstrate the synergistic effect of sorafenib and sulfasalazine in downregulating BCAT2 expression and dictating ferroptotic death, where BCAT2 can also be used to predict the responsiveness of cancer cells to ferroptosis-inducing therapies. Collectively, these findings identify a novel role of BCAT2 in ferroptosis, suggesting a potential therapeutic strategy for overcoming sorafenib resistance.

scholarly journals Genetic and Biochemical Evidence That Haploinsufficiency of the Nf1 Tumor Suppressor Gene Modulates Melanocyte and Mast Cell Fates in Vivo

2000 ◽  
Vol 191 (1) ◽  
pp. 181-188 ◽  
Author(s):  
David A. Ingram ◽  
Feng-Chun Yang ◽  
Jeffrey B. Travers ◽  
Mary Jo Wenning ◽  
Kelly Hiatt ◽  
...  
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Tumor Suppressor ◽  
Tumor Suppressor Genes ◽  
Biological Effects ◽  
Malignant Neoplasms ◽  
Protein Kinase Activity ◽  
Cell Fates ◽  
Suppressor Genes

Neurofibromatosis type 1 (NF1) is a common autosomal-dominant disorder characterized by cutaneous neurofibromas infiltrated with large numbers of mast cells, melanocyte hyperplasia, and a predisposition to develop malignant neoplasms. NF1 encodes a GTPase activating protein (GAP) for Ras. Consistent with Knudson's “two hit” model of tumor suppressor genes, leukemias and malignant solid tumors in NF1 patients frequently demonstrate somatic loss of the normal NF1 allele. However, the phenotypic and biochemical consequences of heterozygous inactivation of Nf1 are largely unknown. Recently neurofibromin, the protein encoded by NF1, was shown to negatively regulate Ras activity in Nf1−/− murine myeloid hematopoietic cells in vitro through the c-kit receptor tyrosine kinase (dominant white spotting, W). Since the W and Nf1 locus appear to function along a common developmental pathway, we generated mice with mutations at both loci to examine potential interactions in vivo. Here, we show that haploinsufficiency at Nf1 perturbs cell fates in mast cells in vivo, and partially rescues coat color and mast cell defects in W41 mice. Haploinsufficiency at Nf1 also increased mast cell proliferation, survival, and colony formation in response to Steel factor, the ligand for c-kit. Furthermore, haploinsufficiency was associated with enhanced Ras–mitogen-activated protein kinase activity, a major downstream effector of Ras, via wild-type and mutant (W41) c-kit receptors. These observations identify a novel interaction between c-kit and neurofibromin in vivo, and offer experimental evidence that haploinsufficiency of Nf1 alters both cellular and biochemical phenotypes in two cell lineages that are affected in individuals with NF1. Collectively, these data support the emerging concept that heterozygous inactivation of tumor suppressor genes may have profound biological effects in multiple cell types.

Sign in / Sign up

Export Citation Format

Share Document