Nomogram to Predict Survival of Patients With Recurrence of Hepatocellular Carcinoma After Surgery.

BACKGROUND & AIMS: We aimed to establish and validate a nomogram to predict survival at 2 and 5 years after recurrence of hepatocellular carcinoma (HCC) in patients who have undergone curative resection. METHODS: We developed a nomogram using data from a training cohort of 638 patients (most with hepatitis B virus infection) with recurrence of HCC after curative resection at Sun Yat-sen University Cancer Center, in Guangzhou, China from 2007 through 2013. The median follow-up time was 39.7 months. Patients were evaluated every 3-4 months for the first 2 years after resection and every 3-6 months thereafter. The nomogram was based on variables independently associated with survival after HCC recurrence, including antiviral treatment; albumin-bilirubin grade and alpha-fetoprotein level at recurrence; time from primary resection to recurrence; size, site, number of recurrences; and treatment for recurrence. We validated the nomogram using data from an independent internal cohort of 213 patients treated at the same institution and an external cohort of 127 patients treated at 2 other centers in China, from 2002 through 2009. The predictive accuracy of the nomogram was measured using Harrell's concordance index (C index) and compared with the Barcelona Clinic Liver Cancer staging system of recurrence. RESULTS: Our nomogram predicted survival of patients in the training cohort with a C-index of 0.797 (95% CI, 0.765-0.830)-greater than that of the Barcelona Clinic Liver Cancer staging system for recurrence (C-index score, 0.713; 95% CI, 0.680-0.745) (P < .001). This nomogram accurately stratified patients into subgroups with predicted long, medium, and short survival times: the proportions of patients in each group who survived 2 years after HCC recurrence were 91.2%, 67.6%, and 23.8%; the proportions of patients in each group who survived 5 years after HCC recurrence were 74.9%, 53.3%, and 9.1%. Our nomogram predicted patient survival times with C-index scores of 0.756 (95% CI, 0.703-0.808) in the internal validation cohort and 0.747 (95% CI, 0.701-0.794) in the external validation cohorts. CONCLUSIONS: We developed a nomogram to determine the probability of survival, at different time points, of patients with recurrence of HCC (most with hepatitis B virus infection), after curative resection and validated it internally and externally.

Transcriptomic Analysis Reveals Candidate Genes Responding Maize Gray Leaf Spot Caused by Cercospora zeina.

Gray leaf spot (GLS), caused by the fungal pathogen Cercospora zeina (C. zeina), is one of the most destructive soil-borne diseases in maize (Zea mays L.), and severely reduces maize production in Southwest China. However, the mechanism of resistance to GLS is not clear and few resistant alleles have been identified. Two maize inbred lines, which were shown to be resistant (R6) and susceptible (S8) to GLS, were injected by C. zeina spore suspensions. Transcriptome analysis was carried out with leaf tissue at 0, 6, 24, 144, and 240 h after inoculation. Compared with 0 h of inoculation, a total of 667 and 419 stable common differentially expressed genes (DEGs) were found in the resistant and susceptible lines across the four timepoints, respectively. The DEGs were usually enriched in 'response to stimulus' and 'response to stress' in GO term analysis, and 'plant-pathogen interaction', 'MAPK signaling pathways', and 'plant hormone signal transduction' pathways, which were related to maize's response to GLS, were enriched in KEGG analysis. Weighted-Genes Co-expression Network Analysis (WGCNA) identified two modules, while twenty hub genes identified from these indicated that plant hormone signaling, calcium signaling pathways, and transcription factors played a central role in GLS sensing and response. Combing DEGs and QTL mapping, five genes were identified as the consensus genes for the resistance of GLS. Two genes, were both putative Leucine-rich repeat protein kinase family proteins, specifically expressed in R6. In summary, our results can provide resources for gene mining and exploring the mechanism of resistance to GLS in maize.

Overexpression of the maize E3 ubiquitin ligase gene ZmAIRP4 enhances drought stress tolerance in Arabidopsis.

Ubiquitin-mediated protein degradation plays a crucial role in enabling plants to effectively and efficiently cope with environmental stresses. The E3 ligases have emerged as a central component of the ubiquitination pathway and modulate plant response to abiotic stresses. However, few such studies have been reported in maize. In this study, a C3HC4-type RING finger E3 ligase in maize, ZmAIRP4 (Zea mays Abscisic acid [ABA]-Insensitive RING Protein 4), which is an ortholog of AtAIRP4, was isolated by reverse transcription polymerase chain reaction with specific primers, and its functions in tolerance to drought stress were described. ZmAIRP4 was upregulated by ABA, polyethylene glycol and sodium chloride. In vitro ubiquitination assays and subcellular localization indicated that ZmAIRP4 was an active E3 ligase predominantly localized in the cytoplasm and nucleus. Compared to wild type, ZmAIRP4-overexpressing Arabidopsis plants were hypersensitive to ABA during early seedling development, and showed enhanced drought tolerance. Moreover, the transcript levels of several drought-related downstream genes in transgenic plants were dramatically increased compared with wild type plants. Our results suggested that E3 ligase ZmAIRP4 is a positive regulator in the drought tolerance response pathway.

[Construction the RFLP linkage map and location the NCBL QTL of maize].

There exists the race differential phenomenon in Exserohilum turcicum (namely NCBL). At present, there are 5 identified races of NCBL and some un-known races in China. For improvement of maize resistance to NCBL, a basic method is to improve maize quantitative resistance. To identify the numbers and effects of the quantitative resistant loci to NCBL in maize, we constructed F2:3 population from resistant line P138 as male parent cross with sensitive line Z3 as female parent. Using RFLP marker technique, the RFLP linkage map of maize was cons cracted covering 1999. 8 cM, and the average distance between markers was 16.5 cM. Identified QTL of NCBL lesion length, width, and area were 3, 3, 2, respectively. The combined contribution ratios of these QTL were 58.1%, 71.5%, 27.5%, respectively. No QTL was identified NCBL lesion number per leaf, it was a trait that might be controlled by one- or oligo-genes. Finally, authors discussed and prospected the maize NCBL research in future.

Genetic diversity and population structure of Miscanthus sinensis germplasm in China.

Miscanthus is a perennial rhizomatous C4 grass native to East Asia. Endowed with great biomass yield, high ligno-cellulose composition, efficient use of radiation, nutrient and water, as well as tolerance to stress, Miscanthus has great potential as an excellent bioenergy crop. Despite of the high potential for biomass production of the allotriploid hybrid M. ×giganteus, derived from M. sacchariflorus and M. sinensis, other options need to be explored to improve the narrow genetic base of M. ×giganteus, and also to exploit other Miscanthus species, including M. sinensis (2n = 2x = 38), as bioenergy crops. In the present study, a large number of 459 M. sinensis accessions, collected from the wide geographical distribution regions in China, were genotyped using 23 SSR markers transferable from Brachypodium distachyon. Genetic diversity and population structure were assessed. High genetic diversity and differentiation of the germplasm were observed, with 115 alleles in total, a polymorphic rate of 0.77, Nei's genetic diversity index (He) of 0.32 and polymorphism information content (PIC) of 0.26. Clustering of germplasm accessions was primarily in agreement with the natural geographic distribution. AMOVA and genetic distance analyses confirmed the genetic differentiation in the M. sinensis germplasm and it was grouped into five clusters or subpopulations. Significant genetic variation among subpopulations indicated obvious genetic differentiation in the collections, but within-subpopulation variation (83%) was substantially greater than the between-subpopulation variation (17%). Considerable phenotypic variation was observed for multiple traits among 300 M. sinensis accessions. Nine SSR markers were found to be associated with heading date and biomass yield. The diverse Chinese M. sinensis germplasm and newly identified SSR markers were proved to be valuable for breeding Miscanthus varieties with desired bioenergy traits.