Cell and Molecular Biology of Cancer Flashcards
Tumout (neoplasm)
Abnormal growth of tissue that usually, but not always, forms a mass
Benign
Do not invade adjacent tissues
Malignant
Invade surrounding tissue and spread to distant parts of the body —> metastasis
Cancer cells acquire 8 traits during their development
- self-sufficient in growth signals
- insensitivity to antigrowth signals
- evasion of apoptosis
- replicated immortality
- sustained angiogenesis
- tissue invasion and metastasis
- reprogramming of energy metabolism
- evasion of immune destruction
Initiation
A mutation causes a normal cell to convert to a precancerous state
Promotion
A promoting agent stimulates cell proliferation
Tumour progression
Through mutations and epigenetic changes cells acquire more aberrant trait and become increasingly aggressive
Oncogenes
Genes whise presence can trigger the development of cancer
Tumour suppressor genes
Genes whose loss or inactivation can trigger the development of the cancer
Retinoblastoma
Rare, rapidly developing cancer from immature retina cells
Properties of cancerous cells
- self-sufficiency in growth signals
- insensitivity to antigrowth signals
- evasion of apoptosis
- replicated immortality
- sustained angiogenesis
- tissue invasion and metastasis
- reprogramming of energy metabolism
- evasion of immune destruction
What does the mutation of oncogenes cause?
Pathways are “switched on” inappropriately —> excessive cell proliferation or promotion of cell survival
HPV produces two oncogenic proteins
E6 and E7
Gatekeeper genes
Its loss directly opens the gates to excessive cell proliferation
Caretaker genes
Maintain genetic stability but are not directly involved in controlling cell proliferation
