DIRAS3

The DIRAS3 gene is a member of a large family of genes known as Ras genes. Genes in this family provide instructions for making proteins that control cell growth and maturation. The DIRAS3 protein differs from other proteins in the Ras family in that it suppresses the growth of cells, whereas other Ras family proteins encourage cell growth. Genes that suppress cell growth and division are known as tumor suppressor genes. The proteins made from these genes keep cells from growing and dividing too fast or in an uncontrolled way.

The DIRAS3 gene provides instructions for making a protein that is located in the fluid within cells (the cytoplasm) and in the cell membrane of normal cells in the breasts and ovaries. It interacts with several other proteins to help control cell growth and division.

In each cell, one copy of the DIRAS3 gene—the copy inherited from a person's mother (the maternal copy)—is nonfunctional throughout life. Only the copy inherited from a person's father (the paternal copy) is active. When the copy of gene inherited from one specific parent is inactivated, this phenomenon is known as genomic imprinting.

breast cancer - associated with the DIRAS3 gene

Research has shown that the tumor suppressor gene DIRAS3 is often downregulated in breast cancer cells, which means its activity is drastically reduced. In some cases, the gene is totally inactivated or lost. Because of genomic imprinting, cells normally have only one working copy of the DIRAS3 gene, the paternal copy. If this copy of the gene is inactivated or lost, cells produce little or no functional DIRAS3 protein. Without enough of this protein, cells can grow and divide too fast and in an uncontrolled manner. This abnormal cell division likely contributes to the growth and progression of cancerous tumors.

other cancers - associated with the DIRAS3 gene

Loss or inactivation of the paternal copy of the DIRAS3 gene is also associated with ovarian cancer. As in breast cancer cells, a shortage of the DIRAS3 protein may allow certain cells in the ovaries to grow and divide too fast and in an uncontrolled manner. This abnormal cell division is associated with the growth and progression of cancerous tumors. Downregulation of the DIRAS3 gene has also been reported in certain forms of uterine cancer, pancreatic cancer, lung cancer, and a cancer of the thyroid gland called follicular thyroid carcinoma.