Hearing function and thresholds: a genome-wide association study in European isolated populations identifies new loci and pathways
JOURNAL OF MEDICAL GENETICS
Authors: Girotto, Giorgia; Pirastu, Nicola; Sorice, Rossella; Biino, Ginevra; Campbell, Harry; d'Adamo, Adamo P.; Hastie, Nicholas D.; Nutile, Teresa; Polasek, Ozren; Portas, Laura; Rudan, Igor; Ulivi, Sheila; Zemunik, Tatijana; Wright, Alan F.; Ciullo, Marina; Hayward, Caroline; Pirastu, Mario; Gasparini, Paolo
Abstract
Background Hearing is a complex trait, but until now only a few genes are known to contribute to variability of this process. In order to discover genes and pathways that underlie auditory function, a genome-wide association study was carried out within the International Consortium G-EAR. Methods Meta-analysis of genome-wide association study's data from six isolated populations of European ancestry for an overall number of 3417 individuals. Results Eight suggestive significant loci (p<10(-7)) were detected with a series of genes expressed within the inner ear such as: DCLK1, PTPRD, GRM8, CMIP. Additional biological candidates marked by a single nucleotide polymorphism (SNP) with a suggestive association (p<10(-6)) were identified, as well as loci encompassing 'gene desert regions'-genes of unknown function or genes whose function has not be linked to hearing so far. Some of these new loci map to already known hereditary hearing loss loci whose genes still need to be identified. Data have also been used to construct a highly significant 'in silico' pathway for hearing function characterised by a network of 49 genes, 34 of which are certainly expressed in the ear. Conclusion These results provide new insights into the molecular basis of hearing function and may suggest new targets for hearing impairment treatment and prevention.
Up-regulation of glycolysis promotes the stemness and EMT phenotypes in gemcitabine-resistant pancreatic cancer cells
JOURNAL OF CELLULAR AND MOLECULAR MEDICINE
Authors: Zhao, Hengqiang; Duan, Qingke; Zhang, Zhengle; Li, Hehe; Wu, Heshui; Shen, Qiang; Wang, Chunyou; Yin, Tao
Abstract
Cancer stem cells (CSCs) and epithelial-mesenchymal transition (EMT)-type cells are considered as underlying causes of chemoresistance, tumour recurrence and metastasis in pancreatic cancer. We aimed to describe the mechanisms - particularly glycolysis - involved in the regulation of the CSC and EMT phenotypes. We used a gemcitabine-resistant (GR) Patu8988 cell line, which exhibited clear CSC and EMT phenotypes and showed reliance on glycolysis. Inhibition of glycolysis using 2-deoxy-D-glucose (2-DG) significantly enhanced the cytotoxicity of gemcitabine and inhibited the CSC and EMT phenotypes in GR cells both in vitro and in vivo. Intriguingly, the use of the reactive oxygen species (ROS) scavenger N-acetylcysteine (NAC) restored the CSC and EMT phenotypes. H2O2 produced changes similar to those of 2-DG, indicating that ROS were involved in the acquired cancer stemness and EMT phenotypes of GR cells. Moreover, doublecortin-like kinase 1 (DCLK1), a pancreatic CSC marker, was highly expressed and regulated the stemness and EMT phenotypes in GR cell. Both 2-DG and H2O2 treatment suppressed DCLK1 expression, which was also rescued by NAC. Together, these findings revealed that glycolysis promotes the expression of DCLK1 and maintains the CSC and EMT phenotypes via maintenance of low ROS levels in chemoresistant GR cells. The glycolysis-ROS-DCLK1 pathway may be potential targets for reversing the malignant behaviour of pancreatic cancer.