Salivary protein biomarkers for screening and diagnosis of oral lichen planus (OLP) are not well-defined. The objective of this study was to identify putative protein biomarkers for OLP using proteomic approaches. Pooled unstimulated whole saliva was collected from five OLP patients and five healthy control participants. Saliva samples were then subjected to two-dimensional gel electrophoresis, followed by mass spectrometry to identify putative protein biomarkers. Subsequently, a subset of these putative biomarkers were validated in 24 OLP patients and 24 age-matched healthy control subjects, using an enzyme-linked immunosorbent assay (ELISA). Immunoblotting analyses were then performed in 3 pairs of age- and sex-matched OLP patients and healthy controls to confirm results from the ELISA study. Thirty-one protein spots were identified, corresponding to 20 unique proteins. Notably, fibrinogen fragment D and complement component C3c exhibited increased expression in OLP patients, while cystatin SA exhibited decreased expression in OLP patients, compared with healthy control subjects. ELISA analyses indicated increased expression of fibrinogen fragment D and complement component C3c, and decreased expression of cystatin SA, in the saliva of OLP patients. Statistical differences in the expression of salivary complement C3c were observed between OLP patients and healthy control subjects. Immunoblotting analyses confirmed the results of our ELISA study. Complement C3c, fibrinogen fragment D and cystatin SA may serve as salivary biomarkers for screening and/or diagnosis of OLP.

The high activation of protein kinase B (AKT)/nuclear factor‑κB (NF‑κB) signaling has often been associated with the induction of non‑small cell lung cancer (NSCLC) cell survival and resistance to cisplatin, which is one of the most widely used chemotherapeutic drugs in the treatment of NSCLC. The inhibition of AKT/NF‑κB can potentially be used as a molecular target for cancer therapy. Eurycomalactone (ECL), a quassinoid from Eurycoma longifolia Jack, has previously been revealed to exhibit strong cytotoxic activity against the human NSCLC A549 cell line, and can inhibit NF‑κB activity in TNF‑α‑activated 293 cells stably transfected with an NF‑κB luciferase reporter. The present study was the first to investigate whether ECL inhibits the activation of AKT/NF‑κB signaling, induces apoptosis and enhances chemosensitivity to cisplatin in human NSCLC cells. The anticancer activity of ECL was evaluated in two NSCLC cell lines, A549 and Calu‑1. ECL decreased the viability and colony formation ability of both cell lines by inducing cell cycle arrest and apoptosis through the activation of pro‑apoptotic caspase‑3 and poly (ADP‑ribose) polymerase, as well as the reduction of anti‑apoptotic proteins Bcl‑xL and survivin. In addition, ECL treatment suppressed the levels of AKT (phospho Ser473) and NF‑κB (phospho Ser536). Notably, ECL significantly enhanced cisplatin sensitivity in both assessed NSCLC cell lines. The combination treatment of cisplatin and ECL promoted cell apoptosis more effectively than cisplatin alone, as revealed by the increased cleaved caspase‑3, but decreased Bcl‑xL and survivin levels. Exposure to cisplatin alone induced the levels of phosphorylated‑AKT and phosphorylated‑NF‑κB, whereas co‑treatment with ECL inhibited the cisplatin‑induced phosphorylation of AKT and NF‑κB, leading to an increased sensitization effect on cisplatin‑induced apoptosis. In conclusion, ECL exhibited an anticancer effect and sensitized NSCLC cells to cisplatin through the inactivation of AKT/NF‑κB signaling. This finding provides a rationale for the combined use of chemotherapy drugs with ECL to improve their efficacy in NSCLC treatment.