Evaluation of Plakophilin-3 mRNA as a biomarker for detection of circulating tumor cells in gastrointestinal cancer patients

[Abstract] Background: This study aims to assess Plakophilin-3 (PKP3) as a surrogate biomarker of circulating tumor cells in patients with gastrointestinal cancer. Methods: The primary aim is to estimate the diagnostic accuracy of PKP3 real-time reverse transcriptase-PCR in blood. Receiver operating characteristic curves were constructed. Correlations between the blood PKP3 levels and the clinicopathologic features of the study subjects were analyzed. Logistic regression was used to predict outcomes based on PKP3. Results: Sixty-four patients with gastrointestinal cancer and 23 controls were included. The mean relative PKP3 mRNA expression was 48.45 in cancer patients and 2.8 in controls (P < 0.0001). Comparing the PKP3 levels in patients and controls, the area under the curve was 0.852 (95% confidence interval, 0.76-0.94; P < 0.0001) in receiver operating characteristic analysis. A higher blood level of PKP3 mRNA was associated with a more advanced stage (P = 0.025), pT3-4 tumors (P = 0.028), metastasis (P = 0.021), and residual (R2) disease (P = 0.037). Higher PKP3 mRNA was associated with the risk of cancer progression and death (odds ratio, 3.875; 95% confidence interval, 1.781-8.430; P = 0.001). Conclusions: Increased PKP3 mRNA was detected in the blood of gastrointestinal cancer patients. Significant correlations were found with advanced stage, pT3-4, metastatic disease, and the residual disease status. PKP3 mRNA in blood was associated with the risk of cancer progression and death.Rede Galega de Investigación sobre Cancro Colorrectal; Grant 509025250

Circulating miR-200c as a diagnostic and prognostic biomarker for gastric cancer

[Abstract] Background. MicroRNAs are aberrantly expressed and correlate with tumourigenesis and the progression of solid tumours. The miR-200 family determines the epithelial phenotype of cancer cells and regulates invasiveness and migration. Thus, we hypothesised that the quantitative detection of the miR-200 family as epithelial-specific microRNAs in the blood could be a useful clinical biomarker for gastric cancer (GC). Methods. We initially validated the expression levels of miR-200a, 200b, 200c and 141 in GC cell lines (n = 2) and blood from healthy controls (n = 19) using real-time quantitative reverse transcription PCR (qRT-PCR). The microarray expression profiles of the miR-200 family in 160 paired samples of non-tumour gastric mucosae and GC were downloaded through ArrayExpress and analysed. MiR-200c was selected for clinical validation. The qRT-PCR prospective assessment of miR-200c was performed using 67 blood samples (52 stage I-IV GC patients and 15 controls); the area under the receiver operating characteristic curve (AUC-ROC) was estimated. The Kaplan-Meier and Breslow-Wilcoxon tests were used to assess the correlation of miR-200c with overall and progression-free survival (OS and PFS). Multivariate analyses were performed using the Cox model. Results. The miR-200c blood expression levels in GC patients were significantly higher than in normal controls (p = 0.018). The AUC-ROC was 0.715 (p = 0.012). The sensitivity, specificity and accuracy rates of 65.4%, 100% and 73.1%, respectively, were observed. The levels of miR-200c in the blood above the cutoff defined by the ROC curve was found in 17.6% of stage I-II GC patients, 20.6% of stage III patients and 67.7% of stage IV patients (p < 0.001). The miR-200c expression levels were not associated with clinical or pathological characteristics or recent surgical procedures. There was a correlation (p = 0.016) with the number of lymph node metastases and the increased expression levels of miR-200c in blood were significantly associated with a poor OS (median OS, 9 vs 24 months; p = 0.016) and PFS (median PFS, 4 vs 11 months; p = 0.044). Multivariate analyses confirmed that the upregulation of miR-200c in the blood was associated with OS (HR = 2.24; p = 0.028) and PFS (HR = 2.27; p = 0.028), independent of clinical covariates. Conclusions. These data suggest that increased miR-200c levels are detected in the blood of gastric cancer patients. MiR-200c has the potential to be a predictor of progression and survival.Instituto de Salud Carlos III; PI061541Xunta de Galicia; PS08/7

Circulating levels of GDF15, MMP7 and miR-200c as a poor prognostic signature in gastric cancer

[Abstract] Aim: To analyze GDF15 and MMP7 serum levels as diagnostic biomarkers in gastric cancer (GC) patients. The prognostic value of GDF15 and MMP7 serum levels in combination with miR-200c blood expression was also analyzed. Patients & methods: Fifty-two GC and 23 control samples were included. Results: GDF15 and MMP7 proved to be powerful tools for GC diagnosis. Increased levels of GDF15 and MMP7 were associated with shorter progression-free survival and overall survival in univariate analysis. In multivariate analysis, the combination of high levels of GDF15, MMP7 and miR-200c was an independent predictor for death (p = 0.033). Conclusion: GDF15 and MMP7 serum levels have diagnostic value for GC. The combination marker formed by GDF15, MMP7 and miR-200c is indicative of adverse evolution in GC patients.Instituto de Salud Carlos III; PI061541Xunta de Galicia; PS087