• Human cancer development is a result of a genetic disease
• Tumour suppressor genes.
• Regulatory expression of these genes can be seen in the normal cells and protein products of these genes are fundamental for normal cell function.
Oncogenes: Ras, Myc, EGFR,c-erbB1,2,3.
Tumour suppressor genes: p53, Rb genes
• Multifactorial etiology.
• The tumour suppressor genes or oncogenes would be altered in the presence of carcinogens:
Four common types of genetic changes
• Deletion : Loss of tumour suppressor genes
• Mutation : p53, Ras
• Inversion : Relocate the the oncogenes in
• Translocation to DNA areas which will leads inappropriate transcription.
• Subsequent accumulation of such growth promoting genetic defects forms the basis of current multi step process of tumourigenesis.
• This multi step process includes.
• Many of the known oncogenes and oncosupressor genes help control mitosis and apoptosis.
• Lack of this control would leads to development of malignancy.
• Genetic disease.
• Substance or group of substance produced by the tumour
• Which can be used as a indicator to detect the presence of the tumour.
A tumour marker should be indicative of :
• Tumour susceptibility of the patient.
• Severity or virulence of the tumour.
• Prognosis of the disease.
• Tumour burden (Including metastasis) .
• Treatment response.
Types of tumour markers:
• Histopathological markers.
• Immuno markers.
• Genetic markers.
• Hormonal markers.
• Protein products of tumours Carcino-embrionic antigen
Apoptosis related genes
• Bcl2 family: Bcl2, Bcl XL , Bax , Bad.