Niko Bla ž evi ć Mentor: A. Ž mega č Horvat

 The process of transformation from a normal cell to a cancerous one  Synonym: neoplasia Carcin ogenes is

 Neoplasia is an abnormality of cell growth and multiplication characterised by:  At cellular level  Excessive cellular proliferation  Uncoordinated growth  Tissue infiltration  At molecular level  Disorder of growth regulatory genes Carcin ogenes is

NORMAL CELL growth factor growth factor receptor signal transduction activation of transcription cytoplasm nucleus DNA RNA Carcin ogenes is

NEOPLASTIC (malignant) CELLS Increase in growth factors Increase in growth factor receptors Increase in signal transduction Increase in activation of transcription - Disturbed processes of mitosis and protein synthesis Carcin ogenes is

 Continuous reproduction  Formation of abnormal proteins  ANAPLASIA: ▪ loss of normal cell function (abnormal DNA transcription) ▪ proliferation ▪ movement of cells ▪ invasion of nearby tissue ▪ metastasis Carcin ogenes is Caused by altered DNA and altered cellular programs which make new signals

 two general types  Monoclonal ▪ initial neoplastic change affects a single cell  Field origin ▪ carcinogen acts on large number of cells producing field of potentially neoplastic cells Carcin ogenes is

Proto-oncogenes ( activated  oncogenes ) – code for: ▪ growth factors ▪ receptors ▪ signal-relay or transduction factors ras - colon cancer myc - lymphoma bcr-abl - chronic myelogenous leukemia (Philladelphia chromosome) Tumor suppressor genes - code for factors that down- regulate the cell cycle, promote differentiation and supress oncogenes from causing cancer Rb-1 – retinoblastoma gene p53 Carcin ogenes is

NEOPLASIA  proto-oncogene is activated or tumor suppressor gene is inactivated normal growth  oncogenesis Activation of proto-oncogene:  point mutation  translocation  gene amplification  Also - Failure of Immune Surveillance theory : immune system responds to neoantigens as to foreign antigens, but neoplastic cells escape recognition and destruction --> become clinical cancers Carcin ogenes is

 Environmental agents  Heredity Carcin ogenes is

 Chemical carcinogens:  hydrocarbons (cigarette smoke, pipe smoke, automobile exhaust gases)  insecticides  dyes  industrial chemicals  insulation  hormones E.g. - DES (diethylstilbestrol) - estrogen drugs Carcin ogenes is

 Radiation:  sunlight  X-rays  radioactive substances  nuclear fusion  Energy interacts with DNA causing its damage and mutation, which leads to CANCER  E.g. - leukemia (radiologists, atomic bomb survivors) - skin cancer – UV radiation from the sun Carcin ogenes is

 Viruses (oncogenic viruses)  HTLV – causes a form of leukemia in adults  Herpes VIII – Kaposi sarcoma  Papilloma virus – cervical carcinoma  Epstein-Barr virus – Burkitt lymphoma Two types – RNA and DNA viruses Carcin ogenes is

 Transmission of some forms of cancer from parents to offspring through defects in the DNA of the egg or sperm cells  E.g.  Retinoblastoma – tumor of the retina of the eye Polyposis coli syndrome – polyps that grow in the colon and rectum Other colon, breast and kidney cancers  Cause: loss of a segment of DNA or a change in the coding sequence of DNA  Detection – DNA sequencing, DNA probes  In many cases – abnormalities in tumor suppressor genes Carcin ogenes is

 Genetic screening – detection of inherited cancer- causing gene by testing the blood cells of family members (inherited changes can be detected in all tissues of the body, not only cancerous cells) Carcin ogenes is

 en.wikipedia.org/wiki/Carcinogenesis  4th year handouts  Google.com ... Carcin ogenes is