Advances in the Characterization of Circulating Tumor Cells in Metastatic Breast Cancer: Single Cell Analyses and Interactions, and Patient-Derived Models for Drug Testing.

Metastasis is the major cause of breast cancer death worldwide. In metastatic breast cancer, circulating tumor cells (CTCs) can be captured from patient blood samples sequentially over time and thereby serve as surrogates to assess the biology of surviving cancer cells that may still persist in solitary or multiple metastatic sites following treatment. CTCs may thus function as potential real-time decision-making guides for selecting appropriate therapies during the course of disease or for the development and testing of new treatments. The heterogeneous nature of CTCs warrants the use of single cell platforms to better inform our understanding of these cancer cells. Current techniques for single cell analyses and techniques for investigating interactions between cancer and immune cells are discussed. In addition, methodologies for growing patient-derived CTCs in vitro or propagating them in vivo to facilitate CTC drug testing are reviewed. We advocate the use of CTCs in appropriate microenvironments to appraise the effectiveness of cancer chemotherapies, immunotherapies, and for the development of new cancer treatments, fundamental to personalizing and improving the clinical management of metastatic breast cancer.

Combination of Resveratrol and Quercetin Causes Cell Growth Inhibition, DNA Damage, Cell Cycle Arrest, and Apoptosis in Oral Cancer Cells.

Resveratrol and quercetin alone are well reported to have anticancer potential, but their combination studies are very inadequate. We have examined their combination in Cal-33 and SCC-15 oral cancer cells (OCCs) and noncancerous HEK-293 cells. Combination of 10 µM concentration of each resveratrol and quercetin brought additive effect on cellular growth, DNA damage, S-phase cell cycle arrest, and cell death in Cal-33 cells but not in the HEK-293 cells. Augmentation of the cell cycle regulatory protein, Cyclin E, and downregulation of Cyclin A possibly caused S-phase arrest in Cal-33 cancer cells. Comet formation and presence of gamma-H2AX foci confirmed DNA damage, and cleavage of PARP1 and upregulation in Bax level specified apoptosis after combined treatment. Ratio of transcription activation and repression histone marks was found increased after alone as well as combined treatment. Histone deacetylase (HDAC)1, HDAC3, and HDAC8 were downregulated by resveratrol alone and combined treatment. Conclusively, combination of resveratrol and quercetin brings cell growth inhibition, DNA damage, and cell cycle arrest in OCCs but not in normal cells. Additionally, combined treatment causes downregulation of HDACs and apoptosis in cancer cells and it could be an incisive strategy against oral cancer.

Angiogenesis Assays.

Neoangiogenesis constitutes one of the first steps of tumor progression beyond a critical size of tumor growth, which supplies a dormant mass of cancerous cells with the required nutrient supply and gaseous exchange through blood vessels essentially needed for their sustained and aggressive growth. In order to understand any biological process, it becomes imperative that we use models, which could mimic the actual biological system as closely as possible. Hence, finding the most appropriate model is always a vital part of any experimental design. Angiogenesis research has also been much affected due to lack of simple, reliable, and relevant models which could be easily quantitated. The angiogenesis models have been used extensively for studying the action of various molecules for agonist or antagonistic behaviour and associated mechanisms. Here, we have described two protocols or models which have been popularly utilized for studying angiogenic parameters. Rat aortic ring assay tends to bridge the gap between in vitro and in vivo models. The chorioallantoic membrane (CAM) assay is one of the most utilized in vivo model system for angiogenesis-related studies. The CAM is highly vascularized tissue of the avian embryo and serves as a good model to study the effects of various test compounds on neoangiogenesis.