Circulating ensembles of tumor-associated cells: A redoubtable new systemic hallmark of cancer.

Circulating ensembles of tumor-associated cells (C-ETACs) which comprise tumor emboli, immune cells and fibroblasts pose well-recognized risks of thrombosis and aggressive metastasis. However, the detection, prevalence and characterization of C-ETACs have been impaired due to methodological difficulties. Our findings show extensive pan-cancer prevalence of C-ETACs on a hitherto unreported scale in cancer patients and virtual undetectability in asymptomatic individuals. Peripheral blood mononuclear cells (PBMCs) were isolated from blood samples of 16,134 subjects including 5,509 patients with epithelial malignancies in various organs and 10,625 asymptomatic individuals with age related higher cancer risk. PBMCs were treated with stabilizing reagents to protect and harvest apoptosis-resistant C-ETACs, which are defined as cell clusters comprising at least three EpCAM+ and CK+ cells irrespective of leucocyte common antigen (CD45) status. All asymptomatic individuals underwent screening investigations for malignancy including PAP smear, mammography, low-dose computed tomography, evaluation of cancer antigen 125, cancer antigen 19-9, alpha fetoprotein, carcinoembryonic antigen, prostate specific antigen (PSA) levels and clinical examination to identify healthy individuals with no indication of cancer. C-ETACs were detected in 4,944 (89.8%, 95% CI: 89.0-90.7%) out of 5,509 cases of cancer. C-ETACs were detected in 255 (3%, 95% CI: 2.7-3.4%) of the 8,493 individuals with no abnormal findings in screening. C-ETACs were detected in 137 (6.4%, 95% CI: 5.4-7.4%) of the 2,132 asymptomatic individuals with abnormal results in one or more screening tests. Our study shows that heterotypic C-ETACs are ubiquitous in epithelial cancers irrespective of radiological, metastatic or therapy status. C-ETACs thus qualify to be a systemic hallmark of cancer.

Reference Size Matching, Whole-Genome Amplification, and Fluorescent Labeling as a Method for Chromosomal Microarray Analysis of Clinically Actionable Copy Number Alterations in Formalin-Fixed, Paraffin-Embedded Tumor Tissue.

Cancer genome copy number alterations (CNAs) assist clinicians in selecting targeted therapeutics. Solid tumor CNAs are most commonly evaluated in formalin-fixed, paraffin-embedded (FFPE) tissue by fluorescence in situ hybridization. Although fluorescence in situ hybridization is a sensitive and specific assay for interrogating preselected genomic regions, it provides no information about coexisting clinically significant copy number changes. Chromosomal microarray analysis is an alternative DNA-based method for interrogating genome-wide CNAs in solid tumors. However, DNA extracted from FFPE tumor tissue produces an essential, yet problematic, sample type. The College of American Pathologists/American Society of Clinical Oncology guidelines for optimal tumor tissue handling, published in 2007 for breast cancer and in 2016 for gastroesophageal adenocarcinomas, are lacking for other solid tumors. Thus, cold ischemia times are seldom monitored in non-breast cancer and non-gastroesophageal adenocarcinomas, and all tumor biospecimens are affected by chemical fixation. Although intended to preserve specimens for long-term storage, formalin fixation causes loss of genetic information through DNA damage. Herein, we describe a reference size matching, whole-genome amplification, and fluorescent labeling method for FFPE-derived DNA designed to improve chromosomal microarray results from suboptimal nucleic acids and salvage highly degraded samples. With this technological advance, whole-genome copy number analysis of tumor DNA can be reliably performed in the clinical laboratory for a wide variety of tissue conditions and tumor types.

Antibiotic resistance in bacteria: novel metalloenzyme inhibitors.

Beta-lactam antibiotics are among the most important drugs used to fight bacterial infection. Overuse and misuse of beta-lactam antibiotics has caused the evolution of resistance mechanisms, allowing pathogenic bacteria to survive antibiotic treatment. The major source of resistance to beta-lactam antibiotics occurs through production of enzymes called beta-lactamases capable of catalyzing hydrolysis of the beta-lactam rings in these drug compounds. The metallo-beta-lactamases have become a major threat due to their broad substrate specificities; there are no clinically useful inhibitors for these metalloenzymes. We have obtained single-stranded DNA's that are potent inhibitors of the Bacillus cereus 5/B/6 metallo-beta-lactamase. These are rapid, reversible, non-competitive inhibitors of the metalloenzyme, with K(i) and K(i)' values in the nanomolar range. The inhibition patterns and metal ion dependence of their inhibition suggest that the oligonucleotides alter the coordination of the active site metal ion(s); inhibition is efficient and highly specific. Microbiological growth experiments, using combinations of ssDNA with the beta-lactam antibiotic cephalexin, reveal that the inhibitor is capable of causing cell death in liquid cultures of both Gram-positive and Gram-negative metallo-beta-lactamase producing bacteria in the micromolar concentration range.