Gene expression profile and bioinformatics analysis revealed key molecular characteristics of chordoma-before and after TNF- a treatment
MEDICINE
Authors: Xu, Guoyong; Liu, Chong; Liang, Tuo; Zhang, Zide; Jiang, Jie; Chen, Jiarui; Xue, Jiang; Zeng, Haopeng; Lu, Zhaojun; Zhan, Xinli
Abstract
Background: Chordoma is a rare malignant tumor with limited treatment. Recent studies have shown that the proliferation and invasion ability of chordoma after Tumor necrosis factor alpha (TNF-alpha) treatment is enhanced, which may activate the gene pathway involved in the development of chordoma. This study tends to identify differentially expressed genes (DEGs) before and after treatment of TNF-alpha in chordoma cell line, providing a new target for future molecular therapy of chordoma. Methods: The gene expression profile of GSE101867 was downloaded from the Gene Expression Omnibus database, and the differentially expressed genes were obtained using GEO2R. Based on the CLUEGO plugin in Cytoscape, DEGs functionality and enrichment analysis. A protein-protein interaction (PPI) network was constructed using Cytoscape based on data collected from the STRING online dataset. The Hub genes are selected from the CytoHubba, the first 20 genes that coexist with the KEGG tumor-related pathway. Results: A total of 560 genes, including 304 up-regulated genes and 256 down-regulated genes, were selected as DEGs. Obviously, GO analysis shows that up-regulated and down-regulated DEGs are mainly enriched in biological processes such as synaptic tissue, cell adhesion, extracellular matrix organization and skeletal system development. DEGs are mainly enriched in tumor-associated pathways such as Pi3k-akt Signal path, Rap1 signal path. Three key genes were identified: PDGFRB, KDR, FGF2. All of these genes are involved in the tumor-associated pathways described previously. Conclusion: This study is helpful in understanding the molecular characteristics of chordoma development. Hub genes PDGFRB, KDR, FGF2 and pi3k-akt signaling pathway, Rap1 signaling pathway will become a new target for the future treatment of chordoma.
Absence of knockdown mutations in pyrethroid and DDT resistant populations of the main malaria vectors in Colombia
MALARIA JOURNAL
Authors: Orjuela, Lorena I.; Alvarez-Diaz, Diego A.; Morales, Juliana A.; Grisales, Nelson; Ahumada, Martha L.; Venegas, Juan H.; Quinones, Martha L.; Yasnot, Maria F.
Abstract
Background Knockdown resistance (kdr) is a well-characterized target-site insecticide resistance mechanism that is associated with DDT and pyrethroid resistance. Even though insecticide resistance to pyrethroids and DDT have been reported in Anopheles albimanus, Anopheles benarrochi sensu lato (s.l.), Anopheles darlingi, Anopheles nuneztovari s.l., and Anopheles pseudopunctipennis s.l. malaria vectors in Latin America, there is a knowledge gap on the role that kdr resistance mechanisms play in this resistance. The aim of this study was to establish the role that kdr mechanisms play in pyrethroid and DDT resistance in the main malaria vectors in Colombia, in addition to previously reported metabolic resistance mechanisms, such as mixed function oxidases (MFO) and nonspecific esterases (NSE) enzyme families. Methods Surviving (n = 62) and dead (n = 67) An. nuneztovari s.l., An. darlingi and An. albimanus mosquitoes exposed to diagnostic concentrations of DDT and pyrethroid insecticides were used to amplify and sequence a 225 bp fragment of the voltage-gated sodium channels (VGSC) gene. This fragment spanning codons 1010, 1013 and 1014 at the S6 segment of domain II to identify point mutations, which have been associated with insecticide resistance in different species of Anopheles malaria vectors. Results No kdr mutations were detected in the coding sequence of this fragment in 129 samples, 62 surviving mosquitoes and 67 dead mosquitoes, of An. darlingi, An. nuneztovari s.l. and An. albimanus. Conclusion Mutations in the VGSC gene, most frequently reported in other species of the genus Anopheles resistant to pyrethroid and DDT, are not associated with the low-intensity resistance detected to these insecticides in some populations of the main malaria vectors in Colombia. These results suggest that metabolic resistance mechanisms previously reported in these populations might be responsible for the resistance observed.