GFP labeling kinetics of triple-negative human breast cancer by a killer-reporter adenovirus in 3D Gelfoam® histoculture

Expression and Targeting of Tumor Markers in Gelfoam® Histoculture: Potential Individualized Assays for Immuno-Oncology

Tumor-specific antigens are important in the study of tumor biology, tumor diagnosis, and prognosis and as targets for tumor therapy. This chapter reviews patient colon, breast, and ovarian tumors in 3-dimensional Gelfoam^® histoculture maintaining in vivo-like expression of the important tumor antigens, for example TAG-72 and CEA. We have also reviewed that fluorescent antibodies can target tumors in Gelfoam^® histoculture, thereby providing an assay for individual patients for sensitivity to therapeutic antibodies which have become so important in immuno-oncology and other cancer therapies.

Clinical Correlation of the Histoculture Drug Response Assay for Head and Neck Cancer

Gelfoam^® histoculture was utilized to develop the histoculture drug response assay (HDRA) for head and neck cancer. Specimens of head and neck tumors were evaluated for sensitivity to the following drugs: cisplatinum (CDDP), 5-fluorouracil (5-FU), and the combination of CDDP and 5-FU. In the first clinical study at UCSD, 10 of 12 patients with tumors that were drug sensitive in Gelfoam^® histoculture had either complete or partial response clinically. Comparisons of HDRA results, obtained with [³H]thymidine incorporation as the endpoint were made with clinical responses, i.e., complete response, partial response, or no response. The overall accuracy of the HDRA was 74% in this correlative clinical trial; the predictive positive value was 83%, the sensitivity was 71%, and the specificity was 78%. Seven of 11 patients with HDRA-resistant tumors demonstrated no response for a predictive negative value of 64%. In a subsequent study at Memorial Sloan Kettering Cancer Center, tumor specimens from 41 to 42 patients undergoing treatment for head and neck cancer were successfully evaluated by the HDRA. The histocultured tumors were treated with 5-FU and/or CDDP and a control group received no drug treatment. After completion of drug treatment, the relative cell survival in the tumors was determined using the MTT endpoint. Sensitivity was defined as a tumor inhibition rate (IR) of greater than 30%. Survival comparisons were performed using the generalized Wilcoxon test for the comparison of Kaplan-Meier survival curves. Resistance to 5-FU was observed in 13 cases (32%), to CDDP in 13 cases (32%), and to both agents in 11 cases (27%). The 2-year cause-specific survival was significantly greater for patients sensitive to 5-FU than patients who were resistant (85% vs. 64%), CDDP (86% vs. 64%), or both agents (85% vs. 63%). These results demonstrate the clinical usefulness of the HDRA for head and neck cancer.

Dynamic changes in the cell membrane on three dimensional low coherent quantitative phase microscopy (3D LC-QPM) after treatment with the near infrared photoimmunotherapy

Near infrared photoimmunotherapy (NIR-PIT) is a newly developed cancer therapy that relies on the binding of a near-infrared antibody photoabsorber conjugate (APC) to a cancer cell. Subsequent exposure to NIR light selectively induces rapid necrotic cell death on target-expressing cells with minimal off-target effects. When treated with NIR-PIT, targeted cells become swollen, develop blebs and burst within minutes of light exposure. Detailed spatial and temporal morphological changes of the cellular membrane of targeted cells treated with NIR-PIT have not been fully explored with state-of-the-art microscopic methods. In this study, we investigated the morphologic and kinetic effects of PIT on two types of cells, a spindle-shaped 3T3/Her cell and a spheric-shaped MDA-MB468 cell, after NIR-PIT using three-dimensional low-coherent quantitative phase microscopy (3D LC-QPM). Adhesive cells treated with NIR-PIT demonstrated region-specific cell membrane rupture occurring first on the distal free edge of the cell near the site of adhesion, in a process that was independent of cell shape. The results show that the peripheral portions of the cell membrane near the site of adhesion are particularly vulnerable to the effects of NIR-PIT, likely because these sites exhibit higher baseline surface tension.