cancer Flashcards
define neoplasia
new growth
define neoplasm
uncontrolled proliferation and growth of cells
/ tumour
what is benign cancer
tumour cells growing locally and not speed by invasion or metastasis
whats malignant cancer
tumour cells invade neighbouring tissues, can enter blood vessels and metastasise to different sites
what are the characterisistcs of benign tumours
- fibrous capsule
- cells divide slowly and closely resemble normal cells
what are characteristics of malignant tumours
- less well differentiated
- invade surrounding tissue
- can get into blood/lymph/spaces and establish secondary growth
1 in 2 ppl in uk get diagnosed with cancer in their lifetime
breast, prostate, bowel and lung cancer account for 50% of all cancer deaths
what are the 2 components of cancer classification
- where they start in the body (e.g breast or lung)
- type of cell or tissue they start in (e.g carcinoma, leukaemia etc)
what are the 5 types of cancer origination
- carcinoma ( skin or tissue of internal organs)
- sarcoma ( bones, cartilage, fat, muscle, connective tissue)
- leukaemia ( bone marrow and causes large no of abnormal blood cells to be produced and enter blood)
- lymphoma and multiple myeloma ( start ion lymphatic system and myeloma starts in plasma cells in bone marrow)
- central nervous system (begin in tissue of brain and spinal cord)
how does cancer begin
genetic mutations/ change in DNA sequence in genes that control cell proliferation etc
can also be influenced by epigenetic changes that affect gene expression on/off
cancer is a multistep process where alterations at genome level cause cells to proliferate out of control, invade and erode normal tissue
what is the biggest risk factor for developing cancer
advancing age
half of all cancers are in ppl over the age of 70
67% cancers are linked to some type of environmental factor
in a general manner, how do cells respond to damaging agentq
- cell sensors to sense damage
- sends signals to arrest cell cycle
- appropriate repair process activated
why is having cell cycle checkpoints important + what are they
it aims to repair any DNA damage and prevent the transmission of damaged/mutated DNA to daughter cells
g1, s, g2 allow repair of lesions before they are converted into permanent mutations
what are proton-oncogenes
Proto-oncogenes are genes that normally help cells grow and divide to make new cells, or to help cells stay alive.
explain the process of protons-oncogenes and normal cell poliferation
- proton-oncogenes encode components of the ells normal growth-control pathway (which are growth factors, receptors, transcription factors and signalling enzymes)
- growth factors bind to receptors on the cell surface, which activate signalling enzymes inside the cell
- the activates transcription factors in the nucleus
- activated transcription factors ‘turn on’ the gene required for cell growth and proliferation
how do tumour suppressor genes stop cell poliferation
- tumour supressor genes are normal genes that instruct cells to produce proteins that restrain cell growth and division / slow down cell growth and division
- the loss of tumour suppressor gene function will allow a cell to grow and divide in an uncontrollable fashion
what is the main purpose of apoptosis
eliminate cells that contain potentially dangerous mutations
if apoptosis function is not working properly, cell can grow and divide uncontrollably and form tumour
how does programmed cell death/apoptosis have a role in homeostatis
- eliminate unwanted cells and tissues, sculpts developing structures, controls cell no and removes abnormal cells
what are the 5 steps in the transformation process of cancer
normal
hyperplasia
mild dysplasia
carcinoma
cancer
what is the Warburg effect (form of cancer reprogramming cellular metabolism)
cancer cells with a metabolic switch to aerobic glycolysis with increased glucose uptake producing only 2 ATP molecules per molecule glucose
an increase in the rate of glucose uptake and preferential production of lactate, even in the presence of oxygen
in contrast to Warburg effect, how do normal cell metabolism work
relies primarily on mitochondrial oxidative phosphorylation with the production of 35 ATP molecules per molecule of glucose
