Cancer Biology 1 - Types of Cancer, Mutations and Viral Oncogenesis Flashcards
What is Cancer
Abnormal growth of cells in an uncontrolled way that can spread of metastasise into other tissues
What are the 2 types of tumours?
Benign and Malignant Tumours
What are Benign Tumours?
Benign tumours are abnormal growths that are no longer under normal regulation
What are Malignant Tumours?
Poorly differentiated cells, growing in a rapid, disorganised manner and can invade surrounding tissues and are become metastatic (initiating the growth of similar tumours in distant organs).
What are the 4 types of cancers based on cell origin?
- Carcinomas
- Sarcomas
- Lymphomas
- Leukaemias
Which is the most common type of cancer and what’s its percentage rate?
- Carcinomas (85%)
- Carcinomas cancer arises from the cells that cover external and internal body surfaces
What are the 4 most frequent Carcinomas Cancers?
- Lung
- Breast
- Colon
- Adenocarcinoma (Glandular epithelial tissue)
What percentage of Cancers are Sarcomas
12%
From which cells does Sarcomas Cancer originate from?
From cells found in the supporting tissues of the body (mesenchymal layer-derived) such as bone, cartilage, fat, connective tissue, and muscle. It is highly malignant.
What percentage of Cancers for Lymphomas and Leukaemia’s make up?
3%
What is Lymphoma?
Lymphomas are cancers that arise in the lymph nodes and tissues of the body immune system (B, T and NK cells) that can spread to intestine, spinal cord, bone or brain.
What is Leukaemia?
Leukaemia is cancer of immature white blood cells that proliferate in the bone marrow and accumulate in the bloodstream.
What 5 factors is staging of cancer based on?
- Site of primary tumour
- Tumour size
- How far it has invaded into local tissues and structures
- Whether it has spread to regional lymph nodes
- Whether it has metastasised to other regions of the body
What is Grading in Cancer
- Based on differences in microscopic cellular appearance, doctors assign a numerical “grade” to most cancers.
- A low number grade (Grade I or II) refers to cancers with fewer cell abnormalities that those with higher grades (Grade III or IV)
Carcinogenesis is a multistep process resulting from the ______________ ____ ____________
Accumulation of mutations
Normal cells evolve into cancer cells through what process?
Tumour Progression
What is Tumour Progression driven by?
It is driven by a series of random mutations and epigenetic alteration (changes in DNA methylation) of DNA that affects the genes controlling proliferation and survival.
Viruses can also cause cancer. True or False
True
What are the 2 viral mechanisms of carcinogenesis?
Indirect and Direct
All tumour viruses probably present direct and indirect mechanisms. True or False
True
Which virus family does the virus EBV belong to?
Herpesviridae
Which virus family does the virus HTLV-I belong to?
Retroviridae
Which virus family does the virus HHV-8d belong to?
Herpesviridae
Which virus family does the virus HBV belong to?
Hepadnaviridae
Which virus family does the virus HCV belong to?
Flaviviridae
Which virus family does the virus HPV belong to?
Papovaviridae
Which virus family does the virus JCVe belong to?
Papovaviridae
Which cells are infected by the EBV virus?
B cells, Oropharyngeal epithelial cells, lymphoid cells
Which cells are infected by the HTLV-I virus?
T cells
Which cells are infected by the HHV-8d virus?
Endothelial cells
Which cells are infected by the HBV virus?
Hepatocytes
Which cells are infected by the HCV virus?
Hepatocytes
Which cells are infected by the HPV virus?
Cervical epithelial
Which cells are infected by the JCVe virus?
Cells in the Central Nervous System
What are 4 causes DNA mutations?
- Mistakes in DNA replication
- Nucleotides within DNA molecules undergo chemical changes spontaneously
- Effect of mutagenic agents
- Viruses
What are the 2 types of mutagenic agents?
- Physical agents (X-rays, UV rays etc)
- Chemical agents (Vinyl chloride, nitrosamines etc)
Name 3 DNA viruses
HBV, EBV, HPV
Can one mutation cause cancer? yes or no
- No - Many mutations are required for cancer
- Cancer is a multi-step process
- 3-20 mutations are required to develop cancer
What is Hyperplasia?
Increase in the number of cells but all cells exhibit normal regulatory control mechanisms.
What is Neoplasia?
After dysplasia and metaplasia (cells become another less differentiated cell) ; neoplastic growth is rapid and results in a tumour, metastasis and acquisition of more mutations.
