Background Serum/plasma YKL-40 can be a useful index that is associated with tumor development. However, the prognostic value of serum/plasma YKL-40 in patients with solid tumors is still unclear. We aimed to utilize the existing literature to investigate the prognostic value of serum/plasma YKL-40 in solid tumors. Methods An extensive literature search for relevant studies was conducted with the Embase, Medline and Web of Science databases. The effect on survival was measured with the hazard ratio (HR). Then, pooled HRs and 95% confidence intervals (CIs) were calculated using the random and fixed-effects models according to the heterogeneity of the included studies. Results This meta-analysis was based on 41 publications and comprised a total of 7762 patients with solid tumors. The pooled HR showed that elevated serum/plasma YKL-40 was significantly associated with poor OS (HR, 1.44; 95% CI 1.33–1.56). We also found that elevated serum/plasma YKL-40 had significant prognostic effects on OS in various cancer subgroups such as gastrointestinal tumors (HR, 1.37; 95% CI 1.18–1.58), ovarian cancer (HR, 2.27; 95% CI 1.69–3.06), melanoma (HR, 1.77; 95% CI 1.18–2.67), lung cancer (HR, 1.73; 95% CI 1.35–2.23), urologic neoplasms (HR, 1.61; 95% CI 1.08–2.40) and glioblastoma (HR, 1.23; 95% CI 1.07–1.42); in contrast, the prognostic effect of serum/plasma YKL-40 was not statistically significant in breast cancer (HR, 1.07; 95% CI 0.98–1.17). Conclusions The available evidence supports the hypothesis that elevated serum/plasma YKL-40 is associated with poor survival in patients with solid tumors and that serum/plasma YKL-40 may serve as a novel prognostic biomarker.

No abstract

In view of the recognized anti‐tumor properties of eugenol against non‐small cell lung cancer (NSCLC) in cell culture, here we further set out to investigate the potential therapeutic effect of eugenol in vivo and elucidate the underlying molecular mechanism. The relative expression levels of TRIM59 and p65 in NSCLC were quantified by real‐time polymerase chain reaction. Xenograft tumor model was established with TRIM59‐deficient H1975 cells, and tumor progression was monitored. Kaplan–Meier's analysis was performed to measure overall survival. Protein levels of TRIM59 and p65 in xenograft tumor were determined by western blot. Direct binding of p65 on the TRIM59 promoter was analyzed by chromatin immunoprecipitation assay, and the regulatory effect was interrogated with luciferase reporter assay. Both TRIM59 and p65 were up‐regulated in NSCLC. Eugenol treatment significantly inhibited xenograft tumor progression and prolonged the overall survival of tumor‐bearing mice. Mechanistically, eugenol suppressed p65 expression, which subsequently decreased TRIM59 expression. TRIM59 deficiency fully recapitulated the anti‐tumoral phenotype elicited by eugenol. Ectopic expression of TRIM59 completely abolished the tumor suppressive effect of eugenol, which underlined the predominant role of TRIM59 in mediating the signaling downstream of eugenol treatment. Eugenol inhibited NSCLC via repression NF‐κB‐TRIM59 pathway.