Background: East Asian, including Thailand, lung cancer population may have a relatively lower prevalence of KRAS mutations than Caucasians. We investigated the prevalence and clinical characteristics of KRAS-driven non-small cell lung cancer (NSCLC) patients and the expression of cyclin D1, one of the KRAS downstream targets.Methods: Lung cancer patients who received treatment at the King Chulalongkorn Memorial Hospital between January 2015 and July 2017 were enrolled. We identified KRAS mutations using allele specific PCR KRAS mutation testing. Cyclin D1 expression was determined using immunohistochemistry.Results: After excluding 376 EGFR mutations and inadequate samples, we enrolled 95 patients eligible for KRAS mutation testing. KRAS mutations were identified in 28 out of 95 patients. There were 26 patients with KRAS codon 12/13 and 2 patients with KRAS codon 61 mutations. The prevalence of KRAS mutations among informative samples was 28 out of 357 (7.8%) which was relatively lower than that reported in Caucasian population. Smoking and male were significantly associated with KRAS mutations. The prognosis of KRAS-mutant NSCLC patients in particular codon 61 mutations was worse than that found in KRAS-and EGFR-wild-type (KRAS WT/EGFR WT) NSCLC patients (P=0.048). The levels of cyclin D1 expression in KRAS-mutant NSCLC were significantly higher than those in KRAS WT/EGFR WT NSCLC (P=0.02).A better prognosis of KRAS-mutant NSCLC patients with low cyclin D1 expression was observed when compared with those with high cyclin D1 expression (median overall survival 41.7 vs. 3.5 months, P=0.037). Conclusions:We found a moderate prevalence of KRAS mutations in lung cancer in Thailand. Clinical characteristics were similar to those of Caucasian population. Most KRAS-mutant NSCLC had high cyclin D1 expression. Cyclin D1 expression may serve as a useful prognostic biomarker in KRAS-mutant lung cancer. Validation of this finding in larger cohort is required.

Cigarette smoke (CS) is a major cause of obstructive lung disease which is associated with significant disability and mortality. Vitamin D receptor (VDR) together with, mitogen activated protein kinases (MAPKs; ERK, JNK and p38) are the cellular transmission signals that mechanistically respond to CS and are recently found to have a role in lung pathogenesis. There are a few in vitro studies on subcellular VDR distribution involved MAPK but in vivo effects of cigarette smoke exposure with and without filter on this complex remain unclear. This study investigated subcellular VDR distribution and MAPK expression at early stages of both types of cigarette smoke exposure (CSE) in a rat model. Male Wistar rats were randomly divided into no-filter, filter and control groups. After 7 and 14 days of CSE, lung tissues were obtained to determine histopathology and protein expression. Cytoplasmic and nuclear VDR distribution significantly decreased on both CSE groups and corresponded with immunohistochemistry detection. The ratio of phosphorylated ERK to total ERK significantly increased in cytoplasm of both CSE on day 7. In particular, nuclear ERK MAPK significantly escalated in the filter group on day 14. In consistent with changes in intracellular markers, histopathological examination in both CSE groups showed significant increases in tracheal and peribronchiolar epithelial proliferation, alveolar macrophages and an increased trend of parenchymal infiltration. In summary, the evidence of lung injuries along with VDR depletion and MAPK activation observed in both CSE types indicated that there was no benefit of using cigarette filter to prevent protein damage or protect cells against cigarette smoke exposure in this model.

Changes in gene expression profiling of peripheral blood mononuclear cells (PBMC) appear to represent the host’s response to the cancer cells via paracrine signaling. We speculated that protein expression on circulating T-lymphocytes represent T-lymphocyte trafficking before infiltration into the tumor microenvironment. The possibility of using protein expression on circulating T-lymphocytes as a biomarker to discriminate early-stage non-small cell lung cancer (NSCLC) was explored. Four independent PBMC gene expression microarray datasets (GSE12771, GSE13255, GSE20189 and GSE3934) were analyzed. We selected C5AR1, CLEC4A and NLRP3 based on their significant protein expression in tumor-infiltrating lymphocytes, but not in normal lymphoid tissue. A validation study using automated flow cytometry was conducted in 141 study participants including 76 treatment-naive early-stage non-small cell lung cancer patients (NSCLC), 12 individuals with non-malignant pulmonary diseases, and 53 healthy individuals. Median ratios of C5AR1, CLEC4A and NLRP3 specific antibody staining to CD3 positive cells in early-stage NSCLC patients compared to healthy controls were 0.014 [0–0.37] vs. 0.01 [0–0.07, p = 0.13], 0.03 [0–0.87] vs. 0.02 [0–0.13, p = 0.10] and 0.19 [0–0.60] vs. 0.09 [0.02–0.31, p < 0.0001], respectively. Median fluorescence intensity (MFI) of CD3+C5AR1+, CD3+CLEC4A+ and CD3+NLRP3+ expression in early-stage NSCLC patients compared to healthy volunteers was 185 [64.2–4801] vs. 107.5 [27–229, p < 0.0001], 91.2 [42.4–2355] vs. 71.25 [46.2–103, p = 0.0005], and 1585 [478–5224] vs. 758.5 [318–1976, p < 0.0001], respectively. NLRP3:CD3 ratio, CD3+C5AR1+, CD3+CLEC4A+ and CD3+NLRP3+ MFI were significantly higher in early-stage NSCLC than healthy volunteers with an area under the ROC curve of 0.69–0.76. The CD3+NLRP3+ MFI provided the most distinguishable expression at 71.5% sensitivity and 70% specificity. Furthermore, CD3+NLRP3+ MFI potentially discriminated between early-stage NSCLC from malignant-mimic inflammation and infection pulmonary disease. Further validation in various pulmonary inflammatory disease might be warranted. Our proof-of-principle findings strengthen the hypothesis that malignancies generate distinctive protein expression fingerprints on circulating T-lymphocytes.