Isolation of tumor-infiltrating lymphocytes from preserved human tumor tissue specimens for downstream characterization.

Immunophenotyping of tumor-infiltrating lymphocytes (TILs) by flow cytometry can predict clinical efficacy of immunotherapy. However, several obstacles need to be overcome for developing a flow cytometry assay starting from solid tumor specimens. Here, we show a detailed enzyme-based protocol to isolate TILs from human tumor tissues.

Drug-induced cell cycle modulation leading to cell-cycle arrest, nuclear mis-segregation, or endoreplication.

Background: Cancer cell responses to chemotherapeutic agents vary, and this may reflect different defects in DNA repair, cell-cycle checkpoints, and apoptosis control. Cytometry analysis only quantifies dye-incorporation to examine DNA content and does not reflect the biological complexity of the cell cycle in drug discovery screens.

Results: Using population and time-lapse imaging analyses of cultured immortalized cells expressing a new version of the fluorescent cell-cycle indicator, Fucci (Fluorescent Ubiquitination-based Cell Cycle Indicator), we found great diversity in the cell-cycle alterations induced by two anticancer drugs.

DNA-binding profiling of human hormone nuclear receptors via fluorescence correlation spectroscopy in a cell-free system.

The nuclear hormone receptors (NHRs), a family of transcription factors, bind directly to the hormone response elements (HREs) to regulate gene expression. In this study, we describe a comprehensive NHR-HRE profiling analysis with a new high-throughput DNA binding assay system utilizing wheat germ cell-free protein production and fluorescence correlation spectroscopy (FCS). This approach revealed NHR binding to natural response elements and new heterodimeric NHR-HRE bindings.

Detection of protein-DNA interactions in crude cellular extracts by fluorescence correlation spectroscopy.

Fluorescence correlation spectroscopy (FCS) is a methodology to examine directly the translational diffusion of individual fluorescence-labeled molecules in solutions. Recent studies using FCS have quantified various bimolecular reactions without any need for amplification. To evaluate further the applicability of FCS, we studied the specific binding between proteins and DNA in crude biological samples.