Differentiation of a colon cancer cell line on a reconstituted basement membrane in vitro

An in-solution ultrasonication-assisted digestion method for improved extracellular matrix proteome coverage

Epithelial cell behavior is coordinated by the composition of the surrounding extracellular matrix (ECM); thus ECM protein identification is critical for understanding normal biology and disease states. Proteomic analyses of ECM proteins have been hindered by the insoluble and digestion-resistant nature of ECM. Here we explore the utility of combining rapid ultrasonication- and surfactant-assisted digestion for the detailed proteomics analysis of ECM samples. When compared with traditional overnight digestion, this optimized method dramatically improved the sequence coverage for collagen I, revealed the presence of hundreds of previously unidentified proteins in Matrigel, and identified a protein profile for ECM isolated from rat mammary glands that was substantially different from that found in Matrigel. In a three-dimensional culture assay to investigate epithelial cell-ECM interactions, mammary epithelial cells were found to undergo extensive branching morphogenesis when plated with mammary gland-derived matrix in comparison with Matrigel. Cumulatively these data highlight the tissue-specific nature of ECM composition and function and underscore the need for optimized techniques, such as those described here, for the proteomics characterization of ECM samples.

Biology of SNU cell lines

SNU (Seoul National University) cell lines have been established from Korean cancer patients since 1982. Of these 109 cell lines have been characterized and reported, i.e., 17 colorectal carcinoma, 12 hepatocellular carcinoma, 11 gastric carcinoma, 12 uterine cervical carcinoma, 17 B-lymphoblastoid cell lines derived from cancer patients, 5 ovarian carcinoma, 3 malignant mixed Mllerian tumor, 6 laryngeal squamous cell carcinoma, 7 renal cell carcinoma, 9 brain tumor, 6 biliary tract, and 4 pancreatic carcinoma cell lines. These SNU cell lines have been distributed to biomedical researchers domestic and worldwide through the KCLB (Korean Cell Line Bank), and have proven to be of value in various scientific research fields. The characteristics of these cell lines have been reported in over 180 international journals by our laboratory and by many other researchers from 1987. In this paper, the cellular and molecular characteristics of SNU human cancer cell lines are summarized according to their genetic and epigenetic alterations and functional analysis.

The prognostic significance of type IV collagen expression in colorectal carcinomas

BACKGROUND: Breakdown of basement membrane is believed to be an essential step for tumor invasion and metastasis. The interaction between tumor cells and extracellular matrix can also result in induction of basement membrane synthesis by tumor and stromal cells. The aim of this study was to investigate distribution patterns of type IV collagen expression at the basement membrane in the tumor tissue of colorectal carcinomas by immunohistochemical staining. The degree of expression of type IV collagen correlated with classical clinicopathologic prognostic factors and their potential relationship with patients' prognosis. PATIENTS AND METHODS: This study included 40 patients who underwent curative resection of colorectal cancer at the Department of Surgery in the General Hospital Senta with complete follow-up for 5 years or until death. The identification of basement membrane was performed immunohistochemically using monoclonal antibodies to collagen IV. The basement membrane synthesis at the invasive front of colorectal cancer was semiquantitatively assessed as mild, moderate or severe. RESULTS: The deposition of basement membrane type of collagen IV had a statistically significant correlation with the stage of disease and histological grade of tumor with tendency of lesser synthesis of basement membrane in the advanced stage of disease and poorer histological grade of tumor. There were no significant correlations between intratumoral basement membrane synthesis and sex and age of patients, and localization and histological type of tumor. Five-year survival rates in patients with mild synthesis of basement membrane in colorectal tumor were significantly lower than in patients with severe expression of basement membrane. The basement membrane synthesis in colorectal cancer was a prognostic factor with significance behind stage of disease and histological grade of tumor by univariate Cox hazard-model. Multivariate Cox analysis verified that explicit synthesis of basement membrane showed a trend toward better prognosis, but it was not statistically significant. CONCLUSION Immunohistochemical staining for type IV collagen is an important additional technique with prognostic value.