Abstract

Genes involved in carcinogenesis include tumor suppressor genes and oncogenes. They produce products involved in the control of cell cycle, intercellular adhesion and DNA repair. Oncogenes arise from protooncogenes that encode proteins having a role in cell’s normal activities. Most tumors contain alterations in both tumor suppressor genes and oncogenes They are derived from protooncogenes and activation of oncogenes can occur by mutation of the gene, duplication of the gene causing gene amplification to produce an excess of encoded protein; or chromosomal rearrangement that causes or alters expression of the gene leading to aberrant cell cycle control. Loss of function of one or more tumor suppressor genes or getting silenced epigenetically can cause cancer. Cells with irreparable genomic damage are destroyed by apoptosis normally. Apoptosis is involved in neurodegenerative disorders (Alzheimer, Parkinson’s, Huntington’s). The immune system is a unique adaptive defensive system to protect from invading pathogenic microorganisms and cancer. The immune response depends on pathogens and can be categorized as innate or adaptive and is produced in response to foreign substances (antigens).

Disorders of immune regulation can be aberrations of quantity, quality or direction of response. Autoimmune diseases can arise from a malfunctioning immune system. Deficiency in antibody production results in agammaglobulinemia, hypogammaglobulinemia and specific immunoglobin deficiency.

Vaccination induces a protective immune response against target pathogens without the risk of acquiring the disease and its potential complications.