Low levels of cell-free circulating miR-361-3p and miR-625* as blood-based markers for discriminating malignant from benign lung tumors.

The high mortality rate of lung cancer patients is mainly due to the late stage at which lung cancer is diagnosed. For effective cancer prevention programs and early diagnosis, better blood-based markers are needed. Hence, blood-based microarray profiling of microRNA (miR) expression was performed in preoperative serum of 21 non-small cell lung cancer (NSCLC) patients and 11 healthy individuals by microfluid biochips containing 1158 different miRs. Two out of the 30 most dysregulated miRs were further validated in serum of 97 NSCLC patients, 20 patients with benign lung diseases and 30 healthy individuals by TaqMan MicroRNA Assays. Microarray profiling showed that miR-361-3p and miR-625* were significantly down-regulated in serum of lung cancer patients. Their further evaluation by quantitative RT-PCR showed that the levels of miR-361-3p and miR-625* were lower in NSCLC than in benign disease (p = 0.0001) and healthy individuals (p = 0.0001, p = 0.0005, respectively). Moreover, the levels of miR-625* were significantly lower in patients with large cell lung cancer (LCLC, p = 0.014) and smoking patients (p = 0.030) than in patients with adenocarcinoma and non-smoking patients, respectively. A rise in the levels of both miRs was observed in the postoperative samples compared with the preoperative levels (p = 0.0001). Functional analyses showed that Smad2 and TGFß1 are not dysregulated by miR-361-3p and miR-625* in the lung cell line A549, respectively. Our present pilot study suggests that miR-361-3p and miR-625* might have a protective influence on the development of NSCLC, and the quantitative assessment of these miRs in blood serum might have diagnostic potential to detect NSCLC, in particular in smokers.

Screening for circulating nucleic acids and caspase activity in the peripheral blood as potential diagnostic tools in lung cancer.

The focus of the current investigational study was to examine whether circulating nucleic acids (i.e., DNA and microRNAs) have the potential to become suitable blood-based markers for diagnosis and progression of lung cancer. The concentrations of cell-free DNA and four circulating microRNAs (miR10b, miR34a, miR141 and miR155) as well as the caspase activity were measured in serum of 35 lung cancer patients (19 non-small-cell lung cancer, 8 small cell lung cancer patients and 8 patients with indefinite cancer type), 7 patients with benign lung tumors and 28 healthy individuals by PicoGreen, TaqMan MicroRNA, and Caspase-Glo®3/7 assay, respectively. The data were correlated with the established risk factors for lung cancer progression. The concentrations of cell-free DNA (p = 0.0001), serum microRNAs (p = 0.0001) and caspase activities (p = 0.0001) significantly discriminated cancer patients from healthy individuals. Serum DNA, caspase activities and RNA levels could not distinguish between patients with benign lung disease and cancer patients. However, the levels of miR10b (p = 0.002), miR141 (p = 0.0001) and miR155 (p = 0.007) were significantly higher in lung cancer patients than those in patients with benign disease. As determined by the Spearman-Rho test, high levels of cell-free DNA significantly correlated with elevated circulating caspase activities (p = 0.0001). In lung cancer patients high serum miR10b values associated with lymph node metastasis (p < 0.03) and elevated levels of TPA (tissue polypeptide antigen, p = 0.01), whereas high serum miR141 values associated with elevated levels of uPA (urokinase plasminogen activator, p = 0.02). The findings of our pilot study suggest that the assays for circulating DNA, microRNAs and caspase activities in blood might become novel minimally invasive diagnostic tools for detection and risk assessment of lung cancer, provided that their clinical utility can be confirmed in larger prospective trials.

Apoptosis-related deregulation of proteolytic activities and high serum levels of circulating nucleosomes and DNA in blood correlate with breast cancer progression.

BACKGROUND: As cell-free circulating DNA exists predominantly as mono- and oligonucleosomes, the focus of the current study was to examine the interplay of circulating nucleosomes, DNA, proteases and caspases in blood of patients with benign and malignant breast diseases. METHODS: The concentrations of cell-free DNA and nucleosomes as well as the protease and caspase activities were measured in serum of patients with benign breast disease (n = 20), primary breast cancer (M0, n = 31), metastatic breast cancer (M1, n = 32), and healthy individuals (n = 28) by PicoGreen, Cell Death Detection ELISA, Protease Fluorescent Detection Kit and Caspase-Glo®3/7 Assay, respectively. RESULTS: Patients with benign and malignant tumors had significantly higher levels of circulating nucleic acids in their blood than healthy individuals (p = 0.001, p = 0.0001), whereas these levels could not discriminate between benign and malignant lesions. Our analyses of all serum samples revealed significant correlations of circulating nucleosome with DNA concentrations (p = 0.001), nucleosome concentrations with caspase activities (p = 0.008), and caspase with protease activities (p = 0.0001). High serum levels of protease and caspase activities associated with advanced tumor stages (p = 0.009). Patients with lymph node-positive breast cancer had significantly higher nucleosome levels in their blood than node-negative patients (p = 0.004). The presence of distant metastases associated with a significant increase in serum nucleosome (p = 0.01) and DNA levels (p = 0.04), and protease activities (p = 0.008). CONCLUSION: Our findings demonstrate that high circulating nucleic acid concentrations in blood are no indicators of a malignant breast tumor. However, the observed changes in apoptosis-related deregulation of proteolytic activities along with the elevated serum levels of nucleosomes and DNA in blood are linked to breast cancer progression.

Impact of platinum-based chemotherapy on circulating nucleic acid levels, protease activities in blood and disseminated tumor cells in bone marrow of ovarian cancer patients.

There is an unmet need for biomarkers for the prediction and monitoring of anticancer therapies. Here, we measured the concentrations of nucleosomes and DNA, protease and caspase activities in serum of 62 patients with ovarian cancer before and after first-line carboplatin/taxane-based chemotherapy and of 28 healthy individuals by Cell Death Detection ELISA, PicoGreen, Protease Fluorescent Detection Kit and Caspase-Glo3/7 Assay, respectively. By immunocytochemistry, we analyzed bone marrow (BM) aspirates for disseminated tumor cells (DTCs) using the monoclonal antibody A45-B/B3. The measurements in blood and BM were correlated to clinical outcome (median follow-up time: 18 months). Significant correlations between circulating nucleosome and DNA concentrations (p = 0.0001), nucleosome concentrations and caspase activities (p = 0.031) and circulating DNA concentrations and protease activities (p = 0.0001) were detected. Before therapy, the occurrence of DTCs correlated with increasing serum protease activities (p = 0.030) and higher tumor stages (p = 0.029), and after therapy, it correlated with a higher risk of relapse (p = 0.040). Higher protease activities in serum were associated with advanced tumor stages (p = 0.045). We observed a significant relationship between residual tumor load of >1 cm after primary surgery and serum DNA levels (p = 0.0001), and both parameters were associated with a higher risk of relapse (p = 0.0001 and p = 0.020, respectively) and a poorer overall survival (p = 0.021 and p = 0.010, respectively). These findings suggest that the residual tumor load might contribute to elevated DNA levels in blood. Serum DNA levels together with BM status for DTCs have the potential to become suitable biomarkers to predict the prognosis of ovarian cancer patients undergoing platinum-based chemotherapy.

Circulating microRNAs as blood-based markers for patients with primary and metastatic breast cancer.

INTRODUCTION: MicroRNAs (miRs) are interesting new diagnostic targets that may provide important insights into the molecular pathogenesis of breast cancer. Here we evaluated, for the first time, the feasibility and clinical utility of circulating miRs as biomarkers for the detection and staging of breast cancer. METHODS: The relative concentrations of breast cancer-associated miR10b, miR34a, miR141 and miR155 were measured in the blood serum of 89 patients with primary breast cancer (M0, n = 59) and metastatic disease (M1, n = 30), and 29 healthy women by a TaqMan MicroRNA Assay. RESULTS: The relative concentrations of total RNA (P = 0.0001) and miR155 (P = 0.0001) in serum significantly discriminated M0-patients from healthy women, whereas miR10b (P = 0.005), miR34a (P = 0.001) and miR155 (P = 0.008) discriminated M1-patients from healthy controls. In breast cancer patients, the changes in the levels of total RNA (P = 0.0001), miR10b (P = 0.01), miR34a (P = 0.003) and miR155 (P = 0.002) correlated with the presence of overt metastases. Within the M0-cohort, patients at advanced tumor stages (pT3 to 4) had significantly more total RNA (P = 0.0001) and miR34a (P = 0.01) in their blood than patients at early tumor stages (pT1 to 2). CONCLUSIONS: This pilot study provides first evidence that tumor-associated circulating miRs are elevated in the blood of breast cancer patients and associated with tumor progression.