Ooocx

retina light-sensitive layer at the rear of the eye

Table 1.

Gene Symbol

Gene Name

Main Tumor Type

Secondary Tumor Type Chromosomal Location

APC

Adenomatous polyposis coli

Familial adenomatous polyposis of the colon

5q21-q22

BRCA1 and 2

Familial breast/ ovarian cancer 1 and 2

Hereditary breast cancer

13q12.3

CDKN1C

Cyclin-dependent

Beckwith-Wiedemann

Wilms' tumor and

11p15.5

kinase inhibitor 1C

syndrome

rhabdomyosarcoma

(p57) gene

MEN1

Multiple endocrine

Multiple endocrine neoplasia

Parathyroid/pituitary

11q13

NF1

Neurofibromatosis

Neurofibromatosis

Neurofibromas, gliomas,

17q11.2

type 1 gene

type 1 syndrome

pheochromocytomas and myeloid leukemia

NF2

Neurofibromatosis

Neurofibromatosis

Bilateral acoustic neuromas,

22q12.2

type 2 gene

type 2 syndrome

meningiomas and ependymomas

TSC1

Tuberous sclerosis type 1

Tuberous sclerosis

Some hamartomas and renal cell carcinoma

9q34

TSC2

Tuberous sclerosis type 2

Tuberous sclerosis

Some hamartomas and renal cell carcinoma

16p13.3

Tumor suppressor genes act as gatekeepers for passage from S

growth mitosis

apoptosis growth

(synthesis) phase to G2 and mitosis. Activation of these genes, which may occur if DNA replication cannot be successfully completed, triggers apoptosis, or programmed cell death.

mitosis apoptosis genes is TP53 (more commonly known as p53). This gene was originally identified as a germ-line mutation in the rare inherited cancer called Li-Fraumeni Syndrome, but it has since been shown to be involved in a wide variety of cancer types. The p53 gene is lost (e.g., the gene is deleted from the chromosome) in about 50 percent of all cancerous cells.

The p53 protein is responsible for controlling the cell cycle checkpoint at the stage where the cell makes a decision to duplicate its genome, called the G2/S boundary. Along with p21 (another essential protein at this boundary), p53 protein monitors the state of the DNA to ensure that the genome is intact and not damaged. The S phase is where the genome is duplicated to get ready for cell division, so it is important that any damage and errors be repaired. If the cell is unable to repair the damage to its DNA, p53 can induce the programmed cell death pathway (called apoptosis) that kills off the cell, thus preventing division of a cell with damaged DNA. If p53 is not functional, the cell cycle is not arrested and any errors will be duplicated and passed on when the cell divides.

0 0

Post a comment