Circular RNA (circRNA) can participate in various biological processes, including tumorigenesis, through their microRNA response elements. Alterations in circRNA profiles during hepatocellular carcinoma (HCC) progression and their clinical significance remain unclear. Here, we present extensive analysis of circRNA profiles in tumor and matched peritumor tissues collected from 10 HCC patients, conducted to identify circRNA related to HCC progression. A total of 42 dysregulated circRNA (38 down‐regulated and 4 up‐regulated) were identified in HCC tumor tissues compared with matched peritumor tissues, revealing the heterogeneity of circRNA profiles in HCC. CircADAMTS13, derived from Exon 13–14 of the ADAMTS13 gene, was significantly downregulated in HCC tumor tissues. Furthermore, clinicopathological analysis revealed that up‐regulation of circADAMTS13 was negatively associated with tumor size but positively associated with prognosis. In addition, overexpression of circADAMTS13 could markedly inhibit HCC cell proliferation in vitro. Bioinformatic analysis and luciferase reporter assays further revealed that circADAMTS13 directly interacts with microRNA (miR)‐484. Rescue experiments showed that miR‐484 mimics can reverse the tumor‐suppressing roles of circADAMTS13 in HCC. Therefore, our results demonstrated that circADAMTS13 can serve as a tumor suppressor during HCC progression via the functional pathway of sponging miR‐484.

An ABA-responsive SnRK2-type kinase, AaAPK1, is involved in positively regulating artemisinin biosynthesis in Artemisia annua through phosphorylation of AabZIP1.

Oleanolic acid glucuronosyltransferase (OAGT) genes synthesizing the direct precursor of oleanane-type ginsenosides were discovered. The four recombinant proteins of OAGT were able to transfer glucuronic acid at C-3 of oleanolic acid that yields oleanolic acid 3-O-β-glucuronide. Ginsenosides are the primary active components in the genus Panax, and great efforts have been made to elucidate the mechanisms underlying dammarane-type ginsenoside biosynthesis. However, there is limited information on oleanane-type ginsenosides. Here, high-performance liquid chromatography analysis demonstrated that oleanane-type ginsenosides (particularly ginsenoside Ro and chikusetsusaponin IV and IVa) are the abundant ginsenosides in Panax zingiberensis, an extremely endangered Panax species in southwest China. These ginsenosides are derived from oleanolic acid 3-O-β-glucuronide, which may be formed from oleanolic acid catalyzed by an unknown oleanolic acid glucuronosyltransferase (OAGT). Transcriptomic analysis of leaves, stems, main roots, and fibrous roots of P. zingiberensis was performed, and a total of 46,098 unigenes were obtained, including all the identified homologous genes involved in ginsenoside biosynthesis. The most upstream genes were highly expressed in the leaves, and the UDP-glucosyltransferase genes were highly expressed in the roots. This finding indicated that the precursors of ginsenosides are mainly synthesized in the leaves and transported to different parts for the formation of particular ginsenosides. For the first time, enzyme activity assay characterized four genes (three from P. zingiberensis and one from P. japonicus var. major, another Panax species with oleanane-type ginsenosides) encoding OAGT, which particularly transfer glucuronic acid at C-3 of oleanolic acid to form oleanolic acid 3-O-β-glucuronide. Taken together, our study provides valuable genetic information for P. zingiberensis and the genes responsible for synthesizing the direct precursor of oleanane-type ginsenosides.