How Does Cancer Develop? Flashcards
What does it mean when we say a tumour is CLONAL?
tumours are clonal meaning they are from one parent
Define clonal
They are from one parent
Clonality assay demonstrates that a group of cells is derived from a single clone
Define clonality
Clonality is 2 tumours deriving from the same progenitor cell that previously underwent malignant changes and gave rise to both of the detected tumours
Define progenitor cell
Progenitor cells are descendants of stem cells that then further differentiate to create specialized cell types
What do we mean when we say a tumour has grown autonomously ?
responding, reacting, or developing independently of the whole
the earliest recognized hallmark of cancer, is fueled by tumor cell’s ability to ‘secrete-and-sense’ growth factors; this translates into cell survival and proliferation that is self-sustained by auto-/paracrine secretion
a tumor is an autonomous growth
As the cancer grows/ develops it’s acquires more mutations, what are some features as the cancer develops
• different shape, size, molecular biology
•each mutation adds a new characteristic/ altered physiology
•autonomous or normal growth signals
What happens when these are mutated:
• p53
When p53 mutated it effects cell cycle edit card add detail
What happens when these are mutated:
• epidermal growth factor
When epidermal growth factor mutated it accelerates growth
What happens when these are mutated:
• vascular endothelial growth factor
When vascular endothelial growth factor mutated it will cause increased ANGIOGENESIS
Angiogenesis
Formation of new blood vessels,
which occurs during wound healing AND is promoted by growth factors (e.g. vascular endothelial growth factor). It’s also seen in malignant tumours + has become a target for anti cancer therapy (angiogenesis inhibitors)
What is Adenomatous polyposis
Adenomatous polyposis is caused by autosomal dominantly inherited mutations in the APC (Adenomatous polyposis coli) gene, a tumour suppressor gene that controls beta-catenin turnover in the Wnt pathway.
Familial adenomatous polyposis (FAP) is an inherited condition that affects the gastrointestinal tract. FAP leads to lots of polyps inside the colon or rectum which can lead to colon (large intestine) or rectal cancer.
What is APC (Adenomatous polyposis coli)
The APC protein acts as a tumor suppressor, which means that it keeps cells from growing and dividing too fast or in an uncontrolled way
APC gene provides instructions for making APC protein : APC regulates the mitotic spindle to facilitate proper chromosome segregation + inhibits DNA replication by interacting directly with DNA
Define hyperplasia
enlargement of an organ or tissue caused by increase in the reproduction rate of its cells, often as an initial stage in development of cancer
What is adenoma
An adenoma is a benign (noncancerous) tumor, a type of polyp. Adenomas start in the glandular epithelial tissue, the tissue that covers your organs and glands. These tumors grow slowly and look like small mushrooms with a stalk.
n.b. THESE CAN BECOME CANCEROUS (these types of polyps are seen in colon and rectal cancer in early stages if someone has mutated APC)
Define adenocarcinoma
a malignant tumour formed from glandular structures in epithelial tissue
E.g. colon cancer
Adenocarcinoma is a subtype of carcinoma. It grows in the glands that line the insides of your organs
what does APC gene stand for
APC = adenomatous polyposis coil
What is K-RAS gene
K-RAS gene is an oncogene that encodes a small GTPase transductor protein called KRAS. KRAS is involved in the regulation of cell division as a result of its ability to relay external signals to the cell nucleus
KRAS is a gene that provides instructions for making a protein called K-Ras, a part of the RAS/MAPK pathway. The protein relays signals from outside the cell to the cell’s nucleus. These signals instruct the cell to grow and divide or to mature and take on specialized functions.
There is a mutation in K-RAS which is involved in the pi3 kinase pathway, what effect will this have
K-RAS is an oncogene. A mutation in K-RAS, a gene commonly associated with various cancers, can lead to the dysregulation of the PI3K (phosphoinositide 3-kinase) pathway. This dysregulation often results in increased cell growth, survival, and proliferation, contributing to tumor development and progression.
What is the pi3 kinase pathway
PI3K-Akt (pi3 kinase) Pathway is an intracellular signal transduction pathway that promotes metabolism, proliferation, cell survival, growth and angiogenesis in response to extracellular signals
What are the 3 germ layers in embryo
Ectoderm (1)
Mesoderm (2)
Endoderm (3)
Tumours are derived from specialised cell types. What places can tumours arise from ectoderm
Epithelia
Nervous tissue
Tumours are derived from specialised cell types. What places can tumours arise from mesoderm
Epithelia
Connective tissue 🥩
Bone 🦴
+ some white blood cells
Tumours are derived from specialised cell types. What places can tumours arise from endoderm
Epithelia
What are the 4 most common epithelial cancers
• lung 🫁
• breast 👩
• prostate 🍆
• colorectal 💩
Examples of squamous cell carcinoma
Nasal cavity
Larynx
Lung
Cervix
Skin
