Prognostic Analysis and Biomarkers Identification of Immune Infiltration in Early and Late Stage Hepatocellular Carcinoma Based on TCGA Data.

Background: Hepatocellular carcinoma (HCC) is a major cause of cancer death in the world. The aim of this study was to establish a new model to predict the prognosis of HCC. Materials and Methods: The mRNA, miRNA and lncRNA expression profiles of early (stage I-II) and late (stage III-IV) stage HCC patients were acquired from The Cancer Genome Atlas (TCGA) database. The differentially expressed mRNAs (DEmRNAs), miRNAs (DEmiRNAs) and lncRNAs (DElncRNAs) were identified between early and late stage HCC. Key molecules associated with the prognosis, and important immune cell types in HCC were identified. The nomogram based on incorporating age, gender, stage, and all important factors was constructed to predict the survival of HCC. Results: A total of 1516 DEmRNAs, 97 DEmiRNAs and 87 DElncRNAs were identified. A DElncRNA-DEmiRNA-DEmRNA regulatory network including 78 mRNAs, 50 miRNAs and 1 lncRNA was established. Among the regulatory network, 11 molecules were significantly correlated with the prognosis of HCC based on Lasso regression analysis. Then, Preadipocytes and 3 survival-associated DEmRNAs were identified as crucial biomarkers. Subsequently, a nomogram with a differentiation degree of 0.758, including 1 immune cell, 11 mRNAs and 3 miRNAs, was generated. Conclusion: Our study constructed a model by incorporating clinical information, significant biomarkers and immune cells to predict the survival of HCC, which achieved a good performance.

Identification of quantitative trait loci that affect endoreduplication in maize endosperm.

Endoreduplication in maize endosperm precedes the onset of starch and storage protein synthesis, and it is generally thought to influence grain filling. We created four backcross populations by reciprocally crossing the F(1) progeny of a cross between Sg18 and Mo17 to the parental inbreds, which differ in endoreduplication by two parameters--mean ploidy and percentage of endoreduplicated nuclei. This four-backcross design allowed us to estimate and test the additive and dominant genetic effects of quantitative trait loci (QTLs) affecting endoreduplication. An analysis of endosperm from the four backcross populations at 16 days after pollination using a modified triploid mapping approach identified three endosperm QTLs influencing mean ploidy and two endosperm QTLs affecting the percentage of endoreduplicated nuclei. Some of these QTLs may manifest their effects on endoreduplication via expression in the embryo. The QTLs detected display strong dominance or over-dominance and interacted epistatically with an embryo-expressed QTL. This helps to explain the genetic basis for transgressive segregation in the backcross progeny. Although the favorable alleles that increase mean ploidy and percentage of endoreduplicated nuclei can be contributed by both parents, the Mo17-derived alleles for endoreduplication were often dominant or over-dominant to the Sg18-derived allele. One QTL on chromosome 7 that may be expressed in both the embryo and endosperm exerted a pleiotropic effect on two different parameters of endoreduplication. The results from this study shed light on the regulation of endoreduplication in maize endosperm and provide a marker-assisted selection strategy for potentially improving grain yield.