The clinical potential of circulating tumor cells; the need to incorporate a modern "immunological cocktail" in the assay.

The accepted clinical assay, CellSearch®, and lab-on-a-chip tests for capturing circulating tumor cells are antibody-mediated. Attempts to improve their sensitivity have relied upon physical changes in the instruments. There have been no significant advances in improving the antibody-mediated portion of the capture.

Immunomagnetic nanoscreening of circulating tumor cells with a motion controlled microfluidic system.

Combining the power of immunomagnetic assay and microfluidic microchip operations, we successfully detected rare CTCs from clinical blood samples. The microfluidic system is operated in a flip-flop mode, where a computer-controlled rotational holder with an array of microfluidic chips inverts the microchannels. We have demonstrated both theoretically and experimentally that the direction of red blood cell (RBC) sedimentation with regards to the magnetic force required for cell separation is important for capture efficiency, throughput, and purity.

Challenges in the enumeration and phenotyping of CTC.

Purpose: Presence of circulating tumor cells (CTC) in metastatic carcinoma is associated with poor survival. Phenotyping and genotyping of CTC may permit "real-time" treatment decisions, provided CTCs are available for examination. Here, we investigate what is needed to detect CTC in all patients.

Molecular profiling of individual tumor cells by hyperspectral microscopic imaging.

We developed a hyperspectral microscopic imaging (HMI) platform that can precisely identify and quantify 10 molecular markers in individual cancer cells in a single pass. The exploitation of an improved separation of circulating tumor cells and the application of HMI provided an opportunity (1) to identify molecular changes in these cells, (2) to recognize the coexpression of these markers, (3) to pose an important opportunity for noninvasive diagnosis, and (4) to use targeted therapy. We balanced the intensity of 10 fluorochromes bound to 10 different antibodies, each specific to a particular tumor marker, so that the intensity of each fluorochrome can be discerned from overlapping emissions.

Microchip-based immunomagnetic detection of circulating tumor cells.

Screening for circulating tumor cells (CTCs) in blood has been an object of interest for evidence of progressive disease, status of disease activity, recognition of clonal evolution of molecular changes and for possible early diagnosis of cancer. We describe a new method of microchip-based immunomagnetic CTC detection, in which the benefits of both immunomagnetic assay and the microfluidic device are combined. As the blood sample flows through the microchannel closely above arrayed magnets, cancer cells labeled with magnetic nanoparticles are separated from blood flow and deposited at the bottom wall of the glass coverslip, which allows direct observation of captured cells with a fluorescence microscope.

Controversies in clinical cancer dormancy.

Clinical cancer dormancy is defined as an unusually long time between removal of the primary tumor and subsequent relapse in a patient who has been clinically disease-free. The condition is frequently observed in certain carcinomas (e.g.

Handheld histology-equivalent sectioning laser-scanning confocal optical microscope for interventional imaging.

A handheld, forward-imaging, laser-scanning confocal microscope (LSCM) demonstrating optical sectioning comparable with microtome slice thicknesses in conventional histology, targeted towards interventional imaging, is reported. Fast raster scanning (approximately 2.5 kHz line scan rate, 3.

Determination of HER2 status using both serum HER2 levels and circulating tumor cells in patients with recurrent breast cancer whose primary tumor was HER2 negative or of unknown HER2 status.

Introduction: At the time when metastatic disease is identified, assessment of human epidermal growth factor receptor (HER)2 status might help to optimize treatment decisions if HER2 status was not determined at first diagnosis and if HER2 positivity has been acquired during disease progression. Within this context, determination of serum HER2 or evaluation of HER2 status in circulating tumor cells (CTCs) may be of clinical relevance because metastatic tissue may be difficult to obtain for analysis as a result of its localization. The aim of this study was therefore to determine the HER2 status in serum and corresponding CTCs in patients with metastatic breast cancer whose primary tumors were HER2 negative or of unknown HER2 status.

Cancer dormancy: lessons from a B cell lymphoma and adenocarcinoma of the prostate.

Cancer dormancy delineates a situation in which residual tumor cells persist in a patient with no apparent clinical symptoms. Although the precise mechanisms underlying cancer dormancy have not been explained, experimental models have provided some insights into the factors that might be involved in the induction and maintenance of a tumor dormant state. The authors of the present chapter studied a murine B cell lymphoma that can be made dormant when interacting with antibodies directed against the idiotype on its immunoglobulin Ig receptor.

uPAR and HER-2 gene status in individual breast cancer cells from blood and tissues.

Overexpression of urokinase plasminogen activator system or HER-2 (erbB-2) in breast cancer is associated with a poor prognosis. HER-2 overexpression is caused by HER-2 gene amplification. The anti-HER-2 antibody trastuzumab significantly improves clinical outcome for HER2-positive breast cancer.

Cancer dormancy: from mice to man.

In this review, we focused on our studies of cancer dormancy in a murine B cell lymphoma and human breast cancer. Lifelong dormancy was induced in syngeneic mice by prior immunization to the idiotype of the tumor cell (TC) Ig before TC challenge. The mice maintained approximately 10(6) lymphoma cells in their spleen throughout their lifetime despite replication of the TCs at a reduced rate.

Circulating tumor cells in patients with breast cancer dormancy.

Purpose: The purpose of this study was to test the hypothesis that circulating tumor cells (CTCs) are present in patients many years after mastectomy without evidence of disease and that these CTCs are shed from persisting tumor in patients with breast cancer dormancy.

Experimental Design: We searched for CTCs in 36 dormancy candidate patients and 26 age-matched controls using stringent criteria for cytomorphology, immunophenotype, and aneusomy.

Results: Thirteen of 36 dormancy candidates, 7 to 22 years after mastectomy and without evidence of clinical disease, had CTCs, usually on more than one occasion.

Mathematical models of cancer dormancy.

The objective of this paper is to present preliminary mathematical models of the interaction between tumor and antibody for the murine BCL1 lymphoma and illustrate how this interaction leads to dormancy of the tumor. We explicitly model the induction by the immune response of cell cycle arrest and apoptosis of the tumor cells. In the absence of large amounts of quantitative data and because the models are preliminary, they are deliberately simple.

Tumor cells circulate in the peripheral blood of all major carcinomas but not in healthy subjects or patients with nonmalignant diseases.

Purpose: The purpose of this study was to determine the accuracy, precision, and linearity of the CellSearch system and evaluate the number of circulating tumor cells (CTCs) per 7.5 mL of blood in healthy subjects, patients with nonmalignant diseases, and patients with a variety of metastatic carcinomas.

Experimental Design: The CellSearch system was used to enumerate CTCs in 7.

Enhancement of the p27Kip1-mediated antiproliferative effect of trastuzumab (Herceptin) on HER2-overexpressing tumor cells.

The oncogenic activity of the overexpressed HER2 tyrosine kinase receptor requires its localization in the plasma membrane. The antitumor effect of anti-HER2 antibodies (Abs) is mainly dependent on receptor downregulation and comprises p27Kip1-mediated G1 cell cycle arrest. However, one major limitation of anti-HER2 therapy is the reversibility of tumor growth inhibition after discontinuation of treatment caused by the mitogenic signaling associated with cell surface receptor re-expression.

HER-2 gene amplification can be acquired as breast cancer progresses.

Amplification and overexpression of the HER-2 oncogene in breast cancer is felt to be stable over the course of disease and concordant between primary tumor and metastases. Therefore, patients with HER-2-negative primary tumors rarely will receive anti-Her-2 antibody (trastuzumab, Herceptin) therapy. A very sensitive blood test was used to capture circulating tumor cells (CTCs) and evaluate their HER-2 gene status by fluorescence in situ hybridization.

Activation of the Syk tyrosine kinase is insufficient for downstream signal transduction in B lymphocytes.

Background: Immature B lymphocytes and certain B cell lymphomas undergo apoptotic cell death following activation of the B cell antigen receptor (BCR) signal transduction pathway. Several biochemical changes occur in response to BCR engagement, including activation of the Syk tyrosine kinase. Although Syk activation appears to be necessary for some downstream biochemical and cellular responses, the signaling events that precede Syk activation remain ill defined.

Patterns of aneusomy for three chromosomes in individual cells from breast cancer tumors.

Multi-color fluorescence in situ hybridization (FISH) can determine the changes in the copy numbers of several chromosomes simultaneously and can therefore be used to identify aneusomic patterns in individual cells. Aneusomic patterns may be useful for determining the malignant nature of rare epithelial cells in the blood of cancer patients. Touch preparations from 74 primary breast tumors were evaluated for aneusomy of chromosomes 1, 8 and 17 by tri-color-FISH.

Cytogenetic evidence that circulating epithelial cells in patients with carcinoma are malignant.

Purpose: Numerous studies of circulating epithelial cells (CECs)have been described in cancer patients, and genetic abnormalities have been well documented. However, with one exception in colorectal cancer, there has been no report of matching the genetic abnormalities in the CECs with the primary tumor. The purpose of this investigation was to determine (a) whether CECs in patients including those with early tumors are aneusomic and (b) whether their aneusomic patterns match those from the primary tumor, indicating common clonality.

Targeting multiple Her-2 epitopes with monoclonal antibodies results in improved antigrowth activity of a human breast cancer cell line in vitro and in vivo.

Her-2 (p185(erbB-2)) is a transmembrane tyrosine kinase receptor, which is encoded by the Her-2/neu proto-oncogene. Her-2 is overexpressed on 30% of highly malignant breast cancers. Monoclonal antibodies (MAbs) against Her-2 inhibit the growth of Her-2-overexpressing tumor cells and this occurs by a variety of mechanisms.