The GPC-16 cell line was established in the early 1980s from colorectal adenocarcinoma tissue excised from a guinea pig (Cavia porcellus) that was administered 56 milligrams of N-methyl-N-nitrosourea intrarectally over a 28-week period. The cells are positive for both PAS (Periodic acid-Schiff) and for keratin by immunoperoxidase staining.

GPC-16 cells are negative for reverse transcriptase, indicating the lack of integral retrovirus genomes. The epithelial cells grow adherently to both plastic and glass surfaces in culture. Studies have demonstrated that GPC-16 cells, which are often utilized in transfection experiments, are tumorigenic in murine specimens.

Colorectal cancer is one of the most common varieties of cancer in the world, and approximately 90 to 95 percent of all colorectal cancers are adenocarcinomas. Included among the many risk factors for the disease are age, a fat- and cholesterol-rich diet, and inflammatory bowel disease. Also, a genetic predisposition that encompasses syndromes such as hereditary polyposis and nonpolyposis may place certain individuals at increased risk for colorectal cancer. In most cases, colorectal adenocarcinomas develop from preexisting adenomatous polyps that form in the colonic mucosa. A well-characterized progression, studies over the last few decades have resulted in the identification of several genetic alterations that develop over many years, eventually becoming key factors in the gradual onset of colorectal cancer. Some of the alterations associated with the disease include mutations in the APC gene, changes in DNA methylation, and chromosome arm 18q deletions.

The proximity of intermediate filaments and the cytoskeletal filamentous actin network was visualized by treating the fixed and permeabilized culture of guinea pig adenocarcinoma cells (GPC-16 line) presented above with mouse anti-vimentin primary antibodies followed by goat anti-mouse secondary antibodies (IgG) conjugated to Cy3. F-actin was subsequently labeled with Coumarin conjugated to phalloidin, and the nuclei were counterstained with SYTOX Green. Images were recorded in grayscale with a 12-bit digital camera coupled to either a Nikon E-600 or Eclipse 80i microscope equipped with bandpass emission fluorescence filter optical blocks. During the processing stage, individual image channels were pseudocolored with RGB values corresponding to each of the fluorophore emission spectral profiles.

Vimentin and Peroxisomal Membrane Proteins in Cultured Guinea Pig Adenocarcinoma Cells - An adherent culture of GPC-16 epithelial cells was treated with a cocktail of mouse anti-vimentin and rabbit anti-PMP 70 primary antibodies, followed by goat anti-mouse and anti-rabbit secondary antibodies conjugated to Cy3 and Alexa Fluor 647, respectively, to target intermediate filaments and peroxisomes. The filamentous actin network was imaged with Coumarin conjugated to phalloidin and DNA in the cell nucleus was counterstained wit SYTOX Green.