Gibberellins (GAs) are a class of important phytohormones regulating a variety of physiological processes during normal plant growth and development. One of the major events during GA-mediated growth is the degradation of DELLA proteins, key negative regulators of GA signaling pathway. The stability of DELLA proteins is thought to be controlled by protein phosphorylation and dephosphorylation. Up to date, no phosphatase involved in this process has been identified. We have identified a dwarfed dominant-negative Arabidopsis mutant, named topp4-1. Reduced expression of TOPP4 using an artificial microRNA strategy also resulted in a dwarfed phenotype. Genetic and biochemical analyses indicated that TOPP4 regulates GA signal transduction mainly via promoting DELLA protein degradation. The severely dwarfed topp4-1 phenotypes were partially rescued by the DELLA deficient mutants rga-t2 and gai-t6, suggesting that the DELLA proteins RGA and GAI are required for the biological function of TOPP4. Both RGA and GAI were greatly accumulated in topp4-1 but significantly decreased in 35S-TOPP4 transgenic plants compared to wild-type plants. Further analyses demonstrated that TOPP4 is able to directly bind and dephosphorylate RGA and GAI, confirming that the TOPP4-controlled phosphorylation status of DELLAs is associated with their stability. These studies provide direct evidence for a crucial role of protein dephosphorylation mediated by TOPP4 in the GA signaling pathway.

Purpose: Our study aimed to investigate whether CAF (cancer-associated fibroblasts) were involved in long noncoding RNAs (lncRNA)-regulated radioresponse in esophageal squamous cell carcinoma (ESCC). Experimental Design: By use of lncRNAs PCR array, 38 lncRNAs were screened in esophageal cancer cells and in normal esophageal epithelial cells Het-1A. LncRNA DNM3OS was detected in tumor tissues of patients with ESCC and in matched normal esophageal epithelial tissues by qRT-PCR analysis and in situ hybridization assay. The association of DNM3OS and tumor radioresistance was investigated in vitro and in vivo. The influences of DNM3OS on DNA damage response (DDR) was investigated by Western blotting, immunofluorescence imaging, and comet assay. The mechanisms by which CAFs promoted DNM3OS expression was investigated by kinase inhibitors' screening, luciferase assay, and chromatin immunoprecipitation. Results: Among the 38 lncRNAs tested, DNM3OS was found to have a much higher expression level in esophageal cancer cells than in Het-1A. In tumor tissues of 16 patients with ESCC, the expression level of DNM3OS showed an average increase of 6.3429-fold compared with that in matched normal tissues. DNM3OS conferred significant radioresistance in vitro and in vivo by regulating DDR. CAFs promoted the expression of DNM3OS with a 39.2554-fold and 38.3163-fold increase in KYSE-30 and KYSE-140, respectively. CAFs promoted the expression of DNM3OS in a PDGFb/PDGFRb/ FOXO1 signaling pathway-dependent manner. FOXO1, a transcription factor downstream of PDGFb/PDGFRb signaling pathway, initiated the transcription of DNM3OS by binding to DNM3OS promoter. Conclusions: Our study highlighted CAF-promoted DNM3OS as an attractive target to reverse tumor radioresistance in ESCC.

Five-year survival rate of esophageal squamous cell carcinoma (ESCC) patients treated with radiotherapy is <20%. Our study aimed to investigate whether cancer-associated fibroblasts (CAFs), one major component of tumor microenvironment, were involved in tumor radioresistance in ESCC. By use of human chemokine/cytokine array, human chemokine CXCL1 was found to be highly expressed in CAFs compared with that in matched normal fibroblasts. Inhibition of CXCL1 expression in CAFs significantly reversed CAF-conferred radioresistance in vitro and in vivo. CAF-secreted CXCL1 inhibited the expression of reactive oxygen species (ROS)-scavenging enzyme superoxide dismutase 1, leading to increased ROS accumulation following radiation, by which DNA damage repair was enhanced and the radioresistance was mediated. CAF-secreted CXCL1 mediated the radioresistance also by activation of Mek/Erk pathway. The cross talk of CAFs and ESCC cells induced CXCL1 expression in an autocrine/paracrine signaling loop, which further enhanced tumor radioresistance. Together, our study highlighted CAF-secreted CXCL1 as an attractive target to reverse tumor radioresistance and can be used as an independent prognostic factor of ESCC patients treated with chemoradiotherapy.

STUDY QUESTION Do cumulative live birth rates (CLBRs) after one complete ART cycle differ between the three commonly used controlled ovarian stimulation (COS) protocols (GnRH antagonist, depot GnRHa (GnRH agonist) and long GnRHa) in normal responders undergoing IVF/ICSI? SUMMARY ANSWER There were similar CLBRs between the GnRH antagonist, depot GnRHa and long GnRHa protocols. WHAT IS KNOWN ALREADY There is no consensus on which COS protocol is the most optimal in women with normal ovarian response. The CLBR provides the final success rate after one complete ART cycle, including the fresh and all subsequent frozen–thawed embryo transfer (ET) cycles. We suggest that the CLBR measure would allow for better comparisons between the different treatment protocols. STUDY DESIGN, SIZE, DURATION A prospective controlled, randomized, open label trial was performed between May 2016 and May 2017. A total of 819 patients were allocated to the GnRH antagonist, depot GnRHa or long GnRHa protocol in a 1:1:1 ratio. The minimum follow-up time from the first IVF cycle was 2 years. To further investigate the potential effect of COS with the GnRH antagonist, depot GnRHa or long GnRHa protocol on endometrial receptivity, the expression of homeobox A10 (HOXA10), myeloid ecotropic viral integration site 1 (MEIS1) and leukemia inhibitory factor (LIF) endometrial receptivity markers was evaluated in endometrial tissue from patients treated with the different COS protocols. PARTICIPANTS/MATERIALS, SETTING, METHODS Infertile women with normal ovarian response (n = 819) undergoing IVF/ICSI treatment were randomized to the GnRH antagonist, depot GnRHa or long GnRHa protocol. Both IVF and ICSI cycles were included, and the sperm samples used were either fresh or frozen partner ejaculates or frozen donor ejaculates. The primary outcome was the live birth rate (LBR) per fresh ET cycle, and the CLBR after one complete ART cycle, until the birth of a first child (after 28 weeks) or until all frozen embryos were used, whichever occurred first. Pipelle endometrial biopsies from 34 female patients were obtained on Days 7–8 after oocyte retrieval or spontaneous ovulation in natural cycles, respectively, and HOXA10, MEIS1 and LIF mRNA and protein expression levels in the human endometrium was determined by quantitative real-time PCR and western blot, respectively. MAIN RESULTS AND THE ROLE OF CHANCE There were no significant differences in CLBRs between the GnRH antagonist, depot GnRHa or long GnRHa protocol (71.4 versus 75.5 versus 72.2%, respectively). However, there was a significantly higher LBR per fresh ET cycle in the depot GnRHa protocol than in the long GnRHa and GnRH antagonist protocols (62.6 versus 52.1% versus 45.6%, P &lt; 0.05). Furthermore, HOXA10, MEIS1 and LIF mRNA and protein expression in endometrium all showed significantly higher in the depot GnRHa protocol than in the long GnRHa and GnRH antagonist protocols (P &lt; 0.05). LIMITATIONS, REASONS FOR CAUTION A limitation of our study was that both our clinicians and patients were not blinded to the randomization for the randomized controlled trial (RCT). An inclusion criterion for the current retrospective cohort study was based on the ‘actual ovarian response’ during COS treatment, while the included population for the RCT was ‘expected normal responders’ based on maternal age and ovarian reserve test. In addition, the analysis was restricted to patients under 40 years of age undergoing their first IVF cycle. Furthermore, the endometrial tissue was collected from patients who cancelled the fresh ET, which may include some patients at risk for ovarian hyperstimulation syndrome, however only patients with 4–19 oocytes retrieved were included in the molecular study. WIDER IMPLICATIONS OF THE FINDINGS The depot GnRH agonist protocol improves the live birth rate per fresh ET cycle, but not the cumulative live birth rate in normal responders. A possible explanation for the improved LBR after fresh ET in the depot GnRHa protocol could be molecular signalling at the level of endometrial receptivity. STUDY FUNDING/COMPETING INTEREST(S) This project was funded by Grant 81571439 from the National Natural Sciences Foundation of China and Grant 2016YFC1000206-5 from the National Key Research & Development Program of China. The authors declare no conflict of interest. TRIAL REGISTRATION NUMBER The RCT trial was registered at the Chinese Clinical Trial Registry, Study Number: ChiCTR-INR-16008220. TRIAL REGISTRATION DATE 5 April 2016. DATE OF FIRST PATIENT’S ENROLLMENT 12 May 2016