Potentially useful biomarkers for the diagnosis, treatment and prognosis of lung cancer

Declines in serum CYFRA21-1 and carcinoembryonic antigen as predictors of chemotherapy response and survival in patients with advanced non-small cell lung cancer

The aim of this study was to investigate the clinical value of serum cytokeratin 19 fragment (CYFRA21-1) and carcinoembryonic antigen (CEA) in the prediction of chemotherapy response and prognosis in patients with advanced non-small cell lung cancer (NSCLC). Serum CYFRA21-1 and CEA levels of 98 patients with advanced NSCLC were measured using immunoradiometric kits prior to and after 2 cycles of chemotherapy. After 2 cycles of chemotherapy, 45 patients achieved a radiological objective response (OR), 30 patients achieved stable disease (SD) and 23 patients had progressive disease (PD). Serum CYFRA21-1 and CEA were significantly decreased compared to baseline levels (P<0.001). By ROC curve analysis, a ≥60% reduction in CYFRA21-1 and a ≥25% reduction in CEA were the optimal cut-off levels with best sensitivity and specificity for the diagnosis of radiologic OR. The median survival of all patients was 10.2 months (range 2.6-26.3). Univariate survival analysis showed that the Eastern Cooperative Oncology Group (ECOG) performance status (PS) score, radiologic OR, a ≥60% reduction in CYFRA21-1 and a ≥25% reduction in CEA were significant prognostic factors for better overall survival. The median overall survival time in patients with a ≥60% reduction in CYFRA21-1 was significantly longer than in those with a <60% reduction (P<0.001). Similarly, the median overall survival time in patients with a ≥25% reduction in CEA was also significantly longer than in those with a <25% reduction (P<0.001). Multivariate analysis showed that ECOG PS score, a ≥60% reduction in CYFRA21-1 and a ≥25% reduction in CEA were independent prognostic factors of survival, while radiologic OR was not. In conclusion, a ≥60% reduction in CYFRA21-1 and a ≥25% reduction in CEA may be reliable surrogate markers for the prediction of chemothrapy response and prognosis, especially for the diagnosis of radiologic OR.

MUC1-associated proliferation signature predicts outcomes in lung adenocarcinoma patients

Background

MUC1 protein is highly expressed in lung cancer. The cytoplasmic domain of MUC1 (MUC1-CD) induces tumorigenesis and resistance to DNA-damaging agents. We characterized MUC1-CD-induced transcriptional changes and examined their significance in lung cancer patients.

Methods

Using DNA microarrays, we identified 254 genes that were differentially expressed in cell lines transformed by MUC1-CD compared to control cell lines. We then examined expression of these genes in 441 lung adenocarcinomas from a publicly available database. We employed statistical analyses independent of clinical outcomes, including hierarchical clustering, Student's t-tests and receiver operating characteristic (ROC) analysis, to select a seven-gene MUC1-associated proliferation signature (MAPS). We demonstrated the prognostic value of MAPS in this database using Kaplan-Meier survival analysis, log-rank tests and Cox models. The MAPS was further validated for prognostic significance in 84 lung adenocarcinoma patients from an independent database.

Results

MAPS genes were found to be associated with proliferation and cell cycle regulation and included CCNB1, CDC2, CDC20, CDKN3, MAD2L1, PRC1 and RRM2. MAPS expressors (MAPS+) had inferior survival compared to non-expressors (MAPS-). In the initial data set, 5-year survival was 65% (MAPS-) vs. 45% (MAPS+, p < 0.0001). Similarly, in the validation data set, 5-year survival was 57% (MAPS-) vs. 28% (MAPS+, p = 0.005).

Conclusions

The MAPS signature, comprised of MUC1-CD-dependent genes involved in the control of cell cycle and proliferation, is associated with poor outcomes in patients with adenocarcinoma of the lung. These data provide potential new prognostic biomarkers and treatment targets for lung adenocarcinoma.

Prognostic significance of urokinase plasminogen activator receptor and its cleaved forms in blood from patients with non-small cell lung cancer

Urokinase plasminogen activator (uPA) cleaves its three-domain cell surface receptor, uPAR, liberating domain I [uPAR(I)] and leaving the cleaved uPAR(II-III) on the cell surface. Both intact and cleaved uPAR can be shed from the cell surface. uPAR(I) was previously shown to be a prognostic factor in lung tumour extracts. Here we analyse uPAR forms in blood from patients with non-small cell lung cancer (NSCLC). Preoperatively sampled plasma/serum from 32 patients with NSCLC was analysed. Three time-resolved fluoroimmunoassays (TR-FIAs) measuring intact uPAR(I-III) (TR-FIA 1), uPAR(I-III) + uPAR(II-III) (TR-FIA 2) and uPAR(I) (TR-FIA 3) were applied. The Spearman rank correlations between plasma and serum levels of uPAR(I-III), uPAR(I-III) + uPAR(II-III), and uPAR(I) were 0.89, 0.94 and 0.68 respectively. Survival analysis demonstrated that high levels of all uPAR forms were associated with shorter survival. Adjusted for histological subtype high plasma uPAR(I-III) and uPAR(I) levels as well as serum uPAR(I) levels were significantly associated with shorter OS (hazards ratios = 4.3, 2.8 and 3.8 respectively). High blood levels of intact uPAR and its cleaved forms are associated with poor prognosis in NSCLC.

Increased expression of enolase alpha in human breast cancer confers tamoxifen resistance in human breast cancer cells

Enolase-alpha (ENO-1) is a key glycolytic enzyme that has been used as a diagnostic marker to identify human lung cancers. To investigate the role of ENO-1 in breast cancer diagnosis and therapy, the mRNA levels of ENO-1 in 244 tumor and normal paired tissue samples and 20 laser capture-microdissected cell clusters were examined by quantitative real-time PCR analysis. Increased ENO-1 mRNA expression was preferentially detected in estrogen receptor-positive (ER+) tumors (tumor/normal ratio >90-fold) when compared to ER-negative (tumor/normal ratio >20-fold) tumor tissues. The data presented here demonstrate that those patients whose tumors highly expressed ENO-1 had a poor prognosis with greater tumor size (>2 cm, *P = .017), poor nodal status (N > 3, *P = .018), and a shorter disease-free interval (<==1 year, *P < .009). We also found that higher-expressing ENO-1 tumors confer longer distance relapse (tumor/normal ratio = 82.8-92.4-fold) when compared to locoregional relapse (tumor/normal ratio = 43.4-fold) in postsurgical 4-hydroxy-tamoxifen (4-OHT)-treated ER+ patients (*P = .014). These data imply that changes in tumor ENO-1 levels are related to clinical 4-OHT therapeutic outcome. In vitro studies demonstrated that decreasing ENO-1 expression using small interfering RNA (siRNA) significantly augmented 4-OHT (100 nM)-induced cytotoxicity in tamoxifen-resistant (Tam-R) breast cancer cells. These results suggest that downregulation of ENO-1 could be utilized as a novel pharmacological approach for overcoming 4-OHT resistance in breast cancer therapy.

Restoration of tumour suppressor hsa-miR-145 inhibits cancer cell growth in lung adenocarcinoma patients with epidermal growth factor receptor mutation

BACKGROUND

In Hong Kong, about 30% of non-small cell lung cancer patients have never smoked tobacco. Among women, 83% are never-smokers and their histological type is invariably adenocarcinoma with 70% incidence of epidermal growth factor receptor (EGFR) mutation. The present study focuses on the microRNA (miRNA) expression profiles of this important subset of lung cancer.

METHODS

Paired samples collected from the lung cancer tissue and adjacent normal lung parenchyma of 10 non-smoking patients with lung adenocarcinoma were profiled by miRNA microarray. Results were validated by quantitative reverse transcription polymerase chain reaction. Transfected cell viability assays were applied to determine the effects of candidate miRNAs on lung cancer cells.

RESULTS

Comparing paired lung cancer tissue with adjacent normal lung parenchyma, hsa-miR-126*, hsa-miR-145, hsa-miR-21, hsa-miR-182, hsa-miR-183 and hsa-miR-210 were found to be the most differentially expressed miRNAs. Most interestingly, an obvious inhibition of cell growth was observed in the EGFR mutant lung adenocarcinoma after transfection of hsa-pre-miR-145.

CONCLUSIONS

Our study is the first report to connect miR-182 to lung cancer. Our results also show that restoration of tumour suppressor hsa-miR-145 inhibits cancer cell growth in EGFR mutant lung adenocarcinoma. Further study on these specific differentially expressed miRNAs may provide important information on peculiar tumourigenetic pathways and may identify useful biomarkers.