Rice (Oryza sativa L.) is a chilling-sensitive staple crop that originated in subtropical regions of Asia. Introduction of the chilling tolerance trait enables the expansion of rice cultivation to temperate regions. Here we report the cloning and characterization of HAN1, a quantitative trait locus (QTL) that confers chilling tolerance on temperate japonica rice. HAN1 encodes an oxidase that catalyzes the conversion of biologically active jasmonoyl-L-isoleucine (JA-Ile) to the inactive form 12-hydroxy-JA-Ile (12OH-JA-Ile) and fine-tunes the JA-mediated chilling response. Natural variants in HAN1 diverged between indica and japonica rice during domestication. A specific allele from temperate japonica rice, which gained a putative MYB cis-element in the promoter of HAN1 during the divergence of the two japonica ecotypes, enhances the chilling tolerance of temperate japonica rice and allows it to adapt to a temperate climate. The results of this study extend our understanding of the northward expansion of rice cultivation and provide a target gene for the improvement of chilling tolerance in rice.

Regulated in development and DNA damage response-1 (REDD1) is a stress-related protein and is involved in the progression of cancer. The role and regulatory mechanism of REDD1 in bladder urothelial carcinoma (BUC), however, is yet unidentified. The expression of REDD1 in BUC was detected by Western blot analysis and immunohistochemistry (IHC). The correlation between REDD1 expression and clinical features in patients with BUC were assessed. The effects of REDD1 on cellular proliferation, apoptosis, autophagy, and paclitaxel sensitivity were determined both and Then the targeted-regulating mechanism of REDD1 by miRNAs was explored. Here the significant increase of REDD1 expression is detected in BUC tissue, and REDD1 is first reported as an independent prognostic factor in patients with BUC. Silencing REDD1 expression in T24 and EJ cells decreased cell proliferation, increased apoptosis, and decreased autophagy, whereas the ectopic expression of REDD1 in RT4 and BIU87 cells had the opposite effect. In addition, the REDD1-mediated proliferation, apoptosis, and autophagy are found to be negatively regulated by miR-22 , which intensify the paclitaxel sensitivity via inhibition of the well-acknowledged REDD1-EEF2K-autophagy axis. AKT/mTOR signaling initially activated or inhibited in response to silencing or enhancing REDD1 expression and then recovered rapidly. Finally, the inhibited REDD1 expression by either RNAi or miR-22 sensitizes BUC tumor cells to paclitaxel in a subcutaneous transplant carcinoma model REDD1 is confirmed as an oncogene in BUC, and antagonizing REDD1 could be a potential therapeutic strategy to sensitize BUC cells to paclitaxel. .

BaCKgRoUND aND aIMS: Hepatocellular carcinoma (HCC) is associated with high malignancy rates. Recently, a known deacetylase silent information regulator 1 (SIRT1) was discovered in HCC, and its presence is positively correlated with malignancy and metastasis. N 6-methyladenosine (m 6 A) is the most prominent modification, but the exact mechanisms on how SIRT1 regulates m 6 A modification to induce hepatocarcinogenesis remain unclear. appRoaCH aND ReSUltS: Here we demonstrate that SIRT1 exerts an oncogenic role by down-regulating fat mass and obesity-associated protein (FTO), which is an m 6 A demethylase. A crucial component of small ubiquitin-related modifiers (SUMOs) E3 ligase, RANBP2, is activated by SIRT1, and it is indispensable for FTO SUMOylation at Lysine (K)-216 site that promotes FTO degradation. Moreover, Guanine nucleotide-binding protein G (o) subunit alpha (GNAO1) is identified as m 6 A downstream targets of FTO and tumor suppressor in HCC, and depletion of FTO by SIRT1 improves m 6 A + GNAO1 and down-regulates its mRNA expression. CoNClUSIoNS: We demonstrate an important mechanism whereby SIRT1 destabilizes FTO, steering the m 6 A + of downstream molecules and subsequent mRNA expression in HCC tumorigenesis. Our findings uncover a target of SIRT1 for therapeutic agents to treat HCC.

Sperm-associated antigen 5 (SPAG5) is involved in various biological processes. However, the roles of SPAG5 in bladder urothelial carcinoma (BUC) are unknown. This study showed that upregulation of SPAG5 was detected frequently in primary BUC tissues, and was associated with significantly worse survival among the 112 patients that underwent radical cystectomy (RC). Up and downregulating the expression of SPAG5 enhanced or inhibited, respectively, the proliferation of BUC cells in vitro and in vivo, and suppressed or enhanced, respectively, apoptosis in vitro and in vivo. Moreover, SPAG5 increased the resistance of BUC cells to chemotherapy-induced apoptosis. Mechanistic investigations showed that SPAG5 promotes proliferation and suppresses apoptosis in BUC at least partially via upregulating Wnt3 through activating the AKT/mTOR signaling pathway. The importance of the SPAG5/AKT-mTOR/Wnt3 axis identified in BUC cell models was confirmed via immunohistochemical analysis of a cohort of human BUC specimens that underwent RC. Collectively, our data suggested that in patients with BUC who underwent RC, high SPAG5 expression is associated with poor survival. In addition, targeting SPAG5 might represent a novel therapeutic strategy to improve the survival of patients with BUC.

Thiamine (vitamin B1) is an essential compound for organisms. It contains a pyrimidine ring structure and a thiazole ring structure. These two moieties of thiamine are synthesized independently and then coupled together. Here we report the molecular characterization of AtTHIC, which is involved in thiamine biosynthesis in Arabidopsis. AtTHIC is similar to Escherichia coli ThiC, which is involved in pyrimidine biosynthesis in prokaryotes. Heterologous expression of AtTHIC could functionally complement the thiC knock-out mutant of E. coli. Downregulation of AtTHIC expression by T-DNA insertion at its promoter region resulted in a drastic reduction of thiamine content in plants and the knock-down mutant thic1 showed albino (white leaves) and lethal phenotypes under the normal culture conditions. The thic1 mutant could be rescued by supplementation of thiamine and its defect functions could be complemented by expression of AtTHIC cDNA. Transient expression analysis revealed that the AtTHIC protein targets plastids and chloroplasts. AtTHIC was strongly expressed in leaves, flowers and siliques and the transcription of AtTHIC was downregulated by extrinsic thiamine. In conclusion, AtTHIC is a gene involved in pyrimidine synthesis in the thiamine biosynthesis pathway of Arabidopsis, and our results provide some new clues for elucidating the pathway of thiamine biosynthesis in plants.

No abstract

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy with a high rate of mortality and recurrence. N6-methyladenosine methylation (m6A) is the most common modification to affect cancer development, but to date, the potential role of m6A regulators in ACC prognosis is not well understood. In this study, we systematically analyzed 21 m6A regulators in ACC samples from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) database. We identified three m6A modification patterns with different clinical outcomes and discovered a significant relationship between diverse m6A clusters and the tumor immune microenvironment (immune cell types and ESTIMATE algorithm). Additionally, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA) revealed that the m6A clusters were strongly associated with immune infiltration in the ACC. Next, to further explore the m6A prognostic signatures in ACC, we implemented Lasso (Least Absolute Shrinkage and Selection Operator) Cox regression to establish an eight-m6A-regulator prognostic model in the TCGA dataset, and the results showed that the model-based high-risk group was closely correlated with poor overall survival (OS) compared with the low-risk group. Subsequently, we validated the key modifications in the GEO datasets and found that high HNRNPA2B1 expression resulted in poor OS and event-free survival (EFS) in ACC. Moreover, to further decipher the molecular mechanisms, we constructed a competing endogenous RNA (ceRNA) network based on HNRNPA2B1, which consists of 12 long noncoding RNAs (lncRNAs) and 1 microRNA (miRNA). In conclusion, our findings indicate the potential role of m6A modification in ACC, providing novel insights into ACC prognosis and guiding effective immunotherapy.

No abstract