Xenopus Dbx2 is involved in primary neurogenesis and early neural plate patterning
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
Authors: Ma, Pengcheng; Zhao, Shuhua; Zeng, Wanli; Yang, Qiutan; Li, Chaocui; Lv, Xiaoyan; Zhou, Qin; Mao, Bingyu
Abstract
The evolutionarily conserved Dbx homeodomain-containing proteins play important roles in the development of vertebrate central nervous system. In mouse, Dbx and Nkx6 have been suggested to be cross-repressive partners involved in the patterning of ventral neural tube. Here, we have isolated Xenopus Dbx2 and studied its developmental expression and function during neural development. Like XDbx1, from mid-neurula stage on, XDbx2 is expressed in stripes between the primary motoneurons and interneurons. At the tailbud stages, it is detected in the middle region of the neural tube. XDbx2 acts as a transcriptional repressor in vitro and over-expression of XDbx2 inhibits primary neurogenesis in Xeno pus embryos. Over-expression of XDbx genes represses the expression of XNkx6.2 and vise versa. Knockdown of either XDbx1, XDbx2 or both by specific morpholinos induces lateral expansion of XNkx6.2 expression domains. These data reveal conserved roles for Dbx in primary neurogenesis and dorsoventral neural patterning in Xenopus. (C) 2011 Elsevier Inc. All rights reserved.
Circulating tumor DNA as an emerging liquid biopsy biomarker for early diagnosis and therapeutic monitoring in hepatocellular carcinoma
INTERNATIONAL JOURNAL OF BIOLOGICAL SCIENCES
Authors: Wu, Xiaolin; Li, Jiahui; Gassa, Asmae; Buchner, Denise; Alakus, Hakan; Dong, Qiongzhu; Ren, Ning; Liu, Ming; Odenthal, Margarete; Stippel, Dirk; Bruns, Christiane; Zhao, Yue; Wahba, Roger
Abstract
As one of the most common malignant tumors worldwide, hepatocellular carcinoma (HCC) is known for its poor prognosis due to diagnosis only in advanced stages. Nearly 50% of the patients with the first diagnosis of HCC die within a year. Currently, the advancements in the integration of omics information have begun to transform the clinical management of cancer patients. Molecular profiling for HCC patients is in general obtained from resected tumor materials or biopsies. However, the resected tumor tissue is limited and can only be obtained through surgery, so that dynamic monitoring of patients cannot be performed. Compared to invasive procedures, circulating tumor DNA (ctDNA) has been proposed as an alternative source to perform molecular profiling of tumor DNA in cancer patients. The detection of abnormal forms of circulating cell-free DNA (cfDNA) that originate from cancer cells (ctDNA) provides a novel tool for cancer detection and disease monitoring. This may also be an opportunity to optimize the early diagnosis of HCC. In this review, we summarized the updated methods, materials, storage of sampling, detection techniques for ctDNA and the comparison of the applications among different biomarkers in HCC patients. In particular, we analyzed ctDNA studies dealing with copy number variations, gene integrity, mutations (RAS, TERT, CTNNB1, TP53 and so on), DNA methylation alterations (DBX2, THY1, TGR5 and so on) for the potential utility of ctDNA in the diagnosis and management of HCC. The biological functions and correlated signaling pathways of ctDNA associated genes (including MAPK/RAS pathway, p53 signaling pathway and Wnt-beta catenin pathway) are also discussed and highlighted. Thus, exploration of ctDNA/cfDNA as potential biomarkers may provide a great opportunity in future liquid biopsy applications for HCC.