HLTH101 Study Guide - Human T-Lymphotropic Virus, Carcinogenesis, Sarcoma
Document Summary
Retrovirus which alters cell dna to cause over expression of proto oncogene which are t cells which over proliferate c ras family of genes (rat sarcoma) code for p 21 proteins communicates signals from outside the cell to the nucleus, mutations in ras genes can permanently activate it and cause inappropriate transmission inside the cell, even in the absence of extracellular signals. Because these signals result in cell growth and division, dysregulated ras signaling can ultimately lead to oncogenesis and cancer. Cause variable damage dependent on loci; damage brain tissue and lead to changes in nervous function: early stage: p53mutation, later stage: gene on chrom 9 code for interferons; immune substances that are believed to attack some tumours mutations then no attack on tumour, 2 other recessive mutations (tumour supressive), dominant mutation (new allele formed) codes for epidermal growth factor receptor/increase responsiveness to growth factor/increase proliferation ;.