Identifying the Best Marker Combination in CEA, CA125, CY211, NSE, and SCC for Lung Cancer Screening by Combining ROC Curve and Logistic Regression Analyses: Is It Feasible?

The detection of serum biomarkers can aid in the diagnosis of lung cancer. In recent years, an increasing number of lung cancer markers have been identified, and these markers have been reported to have varying diagnostic values. A method to compare the diagnostic value of different combinations of biomarkers needs to be established to identify the best combination. In this study, automatic chemiluminescence analyzers were employed to detect the serum concentrations of carcinoembryonic antigen (CEA), carbohydrate antigen 125 (CA125), cytokeratin 19 fragment (CY211), neuron-specific enolase (NSE), and squamous cell carcinoma antigen (SCC) in 780 healthy subjects, 650 patients with pneumonia, and 633 patients with lung cancer. Receiver operating characteristic (ROC) curve and logistic regression analyses were also used to evaluate the diagnostic value of single and multiple markers of lung cancer. The sensitivities of the five markers alone were lower than 65% for lung cancer screening in healthy subjects and pneumonia patients. SCC was of little value in screening lung cancer. After combining two or more markers, the areas under the curves (AUCs) did not increase with the increase in the number of markers. For healthy subjects, the best marker for lung cancer screening was the combination CEA + CA125, and the positive cutoff range was 0.577 CEA + 0.035 CA125 > 2.084. Additionally, for patients with pneumonia, the best screening markers displayed differences in terms of sex but not age. The best screening marker for male patients with pneumonia was the combination CEA + CY211 with a positive cutoff range of 0.008 CEA + 0.068 CY211 > 0.237, while that for female patients with pneumonia was CEA > 2.73 ng/mL, which could be regarded as positive. These results showed that a two-marker combination is more suitable than a multimarker combination for the serological screening of tumors. Combined ROC curve and logistic regression analyses are effective for identifying the best markers for lung cancer screening.

LncRNA-uc.40 silence promotes P19 embryonic cells differentiation to cardiomyocyte via the PBX1 gene.

Uc.40 is a long noncoding RNA that is highly conserved among different species, although its function is unknown. It is highly expressed in abnormal human embryonic heart. We previously reported that overexpression of uc.40 promoted apoptosis and inhibited proliferation of P19 cells, and downregulated PBX1, which was identified as a potential target gene of uc.40. The current study evaluated the effects of uc40-siRNA-44 (siRNA against uc.40) on the differentiation, proliferation, apoptosis, and mitochondrial function in P19 cells, and investigated the relationship between uc.40 and PBX1 in cardiomyocytes. The uc.40 silencing expression was confirmed by quantitative real-time polymerase chain reaction (RT-PCR). Observation of morphological changes in transfected P19 cells during different stages of differentiation revealed that uc40-siRNA-44 increased the number of cardiomyocyes. There was no significant difference in the morphology or time of differentiation between the uc40-siRNA-44 group and the control group. uc40-siRNA-44 significantly promoted proliferation of P19 cells and inhibited serum starvation-induced apoptosis. There was no significant difference in mitochondrial DNA copy number or cellular ATP level between the two groups, and ROS levels were significantly decreased in uc40-siRNA-44-transfected cells. The levels of PBX1 and myocardial markers of differentiation were examined in transfected P19 cells; uc40-siRNA-44 downregulated myocardial markers and upregulated PBX1 expression. These results suggest that uc.40 may play an important role during the differentiation of P19 cells by regulation of PBX1 to promote proliferation and inhibit apoptosis. These studies provide a foundation for further study of uc.40/PBX1 in cardiac development.

Plasma LUNX mRNA, a non-invasive specific biomarker for diagnosis and prognostic prediction of non-small cell lung cancer.

Lung cancer is the most common cancer worldwide. However, no specific biomarker has been found in diagnosis and evaluation of therapeutic efficacy for lung cancer. The human lung-specific X protein gene (LUNX) was recently identified with a feature of lung tissue specificity. We applied the fluorescent quantitative polymerase chain reaction method to examine LUNX mRNA in plasma and peripheral blood mononuclear cells (PBMC) in patients with non-small cell lung cancer (NSCLC), benign lung diseases, extrapulmonary tumors, and healthy subjects. The results showed that LUNX mRNA in both of plasma and PBMC were significantly higher in lung cancer patients compared to other groups. In plasma, there were higher sensitivity and negative predictive value of LUNX mRNA than in PBMC. Patients with III~IV stages of lung cancer had more LUNX mRNA in plasma than the early stage of lung cancer sufferers. After a period of therapy, significant reductions of plasma LUNX mRNA in patients with I and II stages of lung cancer were found. Levels of plasma LUNX mRNA in patients who had succeeded to respond to therapy decreased compared to prior treatment. On the other hand, the post-treatment level was obviously increased in patients that had failed to respond to therapy. Patients with negative plasma LUNX mRNA after therapy displayed a favorable prognosis and survival rate. These preliminary data suggested that cell-free LUNX mRNA in plasma as a non-invasive biomarker, is superior to peripheral intracellular LUNX mRNA, and plays a critical role in specific diagnosis and prognostic prediction of non-small cell lung cancer.