This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. This protein localizes to the endoplasmic reticulum. In rodents, the homologous protein has been shown to metabolize certain carcinogens although its specific function(s) in humans has not been clearly determined. CYP2S1 has been suggested to be involved in the growth and/or spread of certain tumors of
epithelial cell origin: its higher expression in breast or colorectal cancer tissues appears associated respectively with shorter survival times or poor prognoses, and it is more highly expressed in
metastasis compared to primary tumor tissues of ovarian cancer. CYP2S1 has recently been assigned
epoxygenase activity. It metabolizes
1) arachidonic acid to its various epoxides, i.e., the
epoxyeicosatrienoic acids (also termed EETs);
2) docosahexaenoic acid to its various epoxides, i.e. the
epoxydocosapentaenoic acids (also termed EDPs); and
3) linoleic acid to its various epoxides, i.e.
vernolic acid (also termed leukotoxin) and
coronaric acid (also termed isoleukotoxin). It seems likely, although not yet tested, that CYP231 will also prove able to metabolize other
polyunsaturated fatty acids to their epoxides; for example, the enzyme may metabolize
eicosapentaenoic acid to epoxyeicosatetraenoic acids (also termed EEQs). Animal model studies implicate the EET, EDP, and EEQ epoxides in regulating blood pressure, tissue blood flow, new blood vessel formation (i.e.
angiogenesis, pain perception, and the growth of various cancers; limited studies suggest but have not proven that these epoxides may function similarly in humans (see
epoxyeicosatrienoic acid,
epoxydocosapentaenoic acid,
eicosatetraenoic acid, and
epoxygenase pages). The CYP2S1-dependent production of EETs, which stimulate the growth of various types of cancer cells, including those of the colon (see epoxyeicosatrienoic acid#cancer), could contribute to the unfavorable effects of this CYP in the sited cancers. Vernolic and coronaric acids are potentially toxic, causing
multiple organ failure and
acute respiratory distress when injected into animals and suggested to be involved in causing these syndromes in humans. CYP2S1 has also been found to metabolize
Prostaglandin G2 and
Prostaglandin H2 to the biologically active product,
12-Hydroxyheptadecatrienoic acid (i.e. 12(S)-hydroxyheptadeca-5Z,8E,10E-trienoic acid, also termed 12-HHT). == References ==