Carcinogens Lecture Notes

Flashcards covering key vocabulary terms related to carcinogens, cancer development, and DNA damage.

Carcinogen

Any substance capable of causing normal cells to become cancerous.

Oncogene

An altered gene that, when expressed at abnormally high levels, accelerates cell growth and cell division.

Proto-oncogenes

Normal constituents of cells whose function is to promote normal growth and division of cells.

Tumor suppressor genes

Genes that normally function to suppress the formation of cancer in response to certain signals such as DNA damage.

P53

A transcription factor regulating the cell cycle and apoptosis; it blocks cells with damaged DNA from dividing and can trigger apoptosis.

Retinoblastoma (Rb) gene

Inhibits cell cycle at G1 phase; certain tumor antigens combine with Rb, preventing it from inhibiting cell cycle, leading to continuous cell division and cancer.

Growth Factors

Glycoproteins that generally regulate growth by serving as ligands that bind to cellular receptors located on the plasma membrane, stimulating a signal transduction pathway that promotes differentiation.

Mutation

Alteration in the genetic code (DNA sequence of nucleotides) that may result in altered population of cells.

Direct carcinogen

Compounds able to react directly with DNA, causing mutations. They modify DNA to form an 'Adduct'.

Indirect carcinogen

Require prior metabolism to become carcinogenic; procarcinogen is converted to proximate carcinogen then to ultimate carcinogen.

Biotransformation

The process by which the body attempts to eliminate carcinogens by making them more water-soluble for removal.

Initiation (Chemical Carcinogenesis)

Rapid and irreversible damage of DNA.

Promotion (Chemical Carcinogenesis)

Slower process where initiated cells begin to proliferate abnormally; promotors induce cells to grow and divide.