Using modern molecular biology techniques together with human cancer cell lines and an animal model system, Johnson's laboratory is also focusing on the identification of genes that play a role in allowing ovarian epithelial cells to escape normal cell death and causing the formation of a malignant tumor. Johnson's laboratory is studying endocrine factors and associated membrane receptors that can induce cell death, the intracellular second messenger signaling systems that convey such endocrine signals to the cell's nucleus, and the nuclear transcription factors that subsequently mediate gene expression leading to cell death. Determining the mechanisms by which these and other associated genes are controlled and the specific sequence of events that mediate cell death is a major goal of Johnson's research. An understanding of such cellular mechanisms will inevitably lead to more potent and tissue-specific therapeutics to treat ovarian tumors with fewer unwanted side effects. The Walther Center postdoctoral fellow, Cristian Saez, will work with Dr. Subhash C. Basu, professor of chemistry and biochemistry, on glycoconjugates in colorectal cancer.
Colorectal cancer is the third most common cause of cancer-related death in the United States.
Patients with colorectal cancer whose primary tumor has been surgically removed may have distant metastases in the liver and lung. Surgical removal of these metastases is possible only in a limited number of cases, and chemotherapy and radiation therapy are largely ineffective. An understanding of the biochemical mechanism by which metastases occur at specific sites such as the liver, lung or lymph nodes is needed before effective treatment techniques can be developed. The study of the cell surface and its glycoconjugates can lead to new insights into mechanisms for metastatic behavior and possible therapeutic strategies. Sialic acid-dependent receptors have been recognized to play an important role in the adhesion of mammalian cells.