Identification of prognostic immune-related signature predicting the overall survival for colorectal cancer

OBJECTIVE

The morbidity and mortality of patients with colorectal cancer, one of the most common malignant tumors worldwide, is steadily increasing. The aim of this study was to investigate the association between prognostic immune-related gene profile and the outcome of colorectal cancer in patients by analyzing datasets from The Cancer Genome Atlas (TCGA).

MATERIALS AND METHODS

Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) further demonstrated that these genes were enriched in many immune-related biological processes. Univariate Cox regression analysis was applied to examine the association of immune-related genes with the prognosis in patients with colorectal cancer. The least absolute shrinkage and selection operation (LASSO) Cox regression model was then used to establish the immune-related signature for the prognostic evaluation of colorectal cancer in patients. Survival differences were assessed by the Kaplan-Meier method along with the log-rank test.

RESULTS

A total of 133 prognostic immune-related signatures were identified by using the univariate Cox proportional hazards regression analysis. A 14-gene signature-based risk score was constructed using the LASSO Cox regression. According to the cut-off of the risk-score, patients were assigned to the low-risk and high-risk groups. The log-rank test suggested that the survival time of the low-risk group was significantly higher than that of the high-risk group. In the time-dependent ROC curve analysis, the AUC for 1-year, 3-year, and 5-year overall survival (OS) were 0.781, 0.742, and 0.791, respectively. GO and KEGG analysis further revealed that the gene sets were actively involved in immune and inflammatory response, as well as the cytokine-cytokine receptor interaction pathway.

CONCLUSIONS

To summarize, we identified a novel 14-gene immune-related signature that may potentially serve as a prognostic predictor for colorectal cancer, thereby contributing to patient personalized treatment decisions. Further research needs to be conducted to validate the prognostic value of the selected genes.

Identification of quantitative trait loci controlling resistance to gray leaf spot disease in maize

Breeding maize for gray leaf spot (GLS) resistance has been hindered by the quantitative nature of the inheritance of GLS resistance and by the limitations of selection under less than optimumal disease pressure. In order to identify the quantitative trait loci (QTLs) controlling GLS resistance, a cross was made between B73 (susceptible) and Va14 (resistant) to generate a large F2 population. Six GLS disease assessments were made throughout the disease season for over 1000 F2 plants in 1989, and for 600 F2-derived F3 lines replicated in two blocks in 1990. RFLP analysis for78 marker loci representing all ten maize chromosomes was conducted in 239 F2 individuals including those with the extreme GLS disease phenotypes. The GLS disease scores of the three field evaluations, each averaged over six ratings, were separately used for the interval mapping in order to determine the consistency of the QTL effects. The heavy GLS disease pressure, meticulous disease ratings, and large population size of this study afforded us the sensitivity for detecting QTL effects. QTLs located on three chromosomes (1, 4, and 8) had large effects on GLS resistance, each explaining 35.0-56.0%, 8.8-14.3%, and 7.7-11.0% of the variance, respectively. These three QTL effects were remarkably consistent across three disease evaluations over 2 years and two generations. Smaller QTL effects were also found on chromosomes 2 and 5, but the chromosome-5 effect might be a false positive because it was not repeatable even in the same location. The chromosome-1 QTLs had the largest effect or highest R(2) reported for any quantitative trait to-date. Except for the chromosome-4 gene, which was from the susceptible parent B73, the resistance alleles at all QTL were derived from Va14. The resistance QTLs on chromosomes 1 and 2 appear to have additive effects, but those on chromosomes 4 and 8 are dominant and recessive, respectively. Significant interaction between the QTLs on chromosomes 1 and 4 was detected in all three evaluations. Cumulatively, the four QTLs identified in this study explained 44, 60, and 68% of the variance in F2, and in F3 replications 1 and 2, respectively.

[Protective effects of an ethanolic extract and essential oil of Curcuma kwangsinensis S. against experimental liver lesions in mice]

The ethanolic extract and the essential oil of Curcuma kwangsinensis were found to be effective in lowering the elevated SGPT induced by CCl4, TAA and BSP retention. Histological examination showed that hepatic damages of the extract-and oil-pretreated mice were less than those of the CCl4 control group. The ethanolic extract helped to shorten sodium pentobarbital sleeping time in both normal and CCl4 intoxicated mice. In addition, the essential oil exhibited an inhibitory effect on triglyceride accumulation in mice. The toxicity of the extract and the oil was found to be low: oral LD50 was 86.8 +/- 12g crude drug/kg (ethanolic extract) and 1.10 +/- 0.08g/kg (essential oil).