The biology of a Cancer Cell - Slide set 1

Carcinogenesis

Process that cancer goes through

Tumor

Uncontrolled cells that grow to a solid mass

Leukemia

A unconnected and free-floating type of cancer (tumor)

Benign tumor

Tumor mass that is contained by a capsle of connective tissue, they aren’t able to wander and are not cancer.

Malignant

If the tumor cells escape from their site of origin and invade neighboring tissue.

Metastases

Cancer cells wander off and colonize distant sites.

Cancer

Set of disease characterized by unregulated cell grouth leading the the invation of surround tissue and mass spread (metastasis).

Neoplasm

Mass/growth that is incoordinate with the surrounding normal tissues and keeps going in the absence of the inciting stimulus.

Hyperplasia

Normal cells proliferating, non-malignant condition

Cancers are antisocial

They have a degree of autonomy not enjoyed by their normal countarparts.

Tumor Suppressor Genes

Genes that slow down cancer development. Cancer cells have mutations that inactivate the function of these genes.

Oncogenics

Genes that, when hyperactive, promote cancer development. Cancer cells have mutations that enhance the activity of these genes.

How do cancers start

Most cancers start as a growth from a single cell that replicates and mutates until it makes a large mass and can be life-threatening.

Tumor behavior

Monoclonal origin but polyclonal existence.

Cancer stem cell hypothesis

Tumor grows thanks to endlis duplication of a few stem cells.

Genes commonly mutated in cancer fall into two categories

Tumor suppressor genes and oncoenics.

Tumor suppressor genes

Genes that slow down cancer development. Cancer cells have mutations that inactiveate their function.

Oncogenics

Genes that, when hyperactive, promote cancer development. Cancer cells hyperactivate them.

How could tumor suppressor genes be inactivated?

Gene deletions, inactivating missense mutations, inactivating microdeletions or insertions and frameshifts, or promoter silencing.

How could oncogene activity be increased?

Gene amplification, activating point mutation, promoter hyperactivity

The accumulation of multiple mutaions in single somatic cells is very improbable

Therefore, the road to cancer is likely to involve the introduction of abnormal genetic instability into the genome of the cell that is becoming cancerous. Even with an unstable genome, it takes time to accumulate the multiple mutations that are required, which may explain why cancer is more common in older people than in the young.

More people die of cancer

25% of US deaths. This is likely due to the fact that people live longer now than they did before. Modern medication allows people to not pass from other diseases. Cancer is the number one cause of death in the male population in the US, and will be the number one overall.