cancer genetics 1

Hypertrophy

Increase in cell size with normal organization

Hyperplasia

Increase in cell number with normal organization

Dysplasia

Disorganized cell growth

Neoplasia

Disorganized abnormal growth with a net increase in dividing cells

Tumor

A proliferating mass of abnormal cells

Monoclonal tumor

A tumor whose cells mostly originated from one single cell

Benign tumor

Local slow-growing well-differentiated tumor that is usually encapsulated

Malignant tumor

Invasive tumor that may metastasize and often has abnormal organization

Benign tumor microscopic traits

Small regular nuclei, low mitotic index, normal organization, encapsulated

Malignant tumor microscopic traits

Large irregular nuclei, high mitotic index, abnormal organization, & poorly defined boundaries

Cancer

Uncontrolled growing mass of cells capable of invading surrounding tissue and spreading

Invasion

Movement of cancer cells into nearby surrounding tissue

Metastasis

Spread of cancer cells to distant sites through the body

Do all cancers invade?

Yes

Do all cancers metastasize?

No

Carcinoma

Cancer of epithelial origin

Sarcoma

Cancer of supporting tissue origin

Lymphoma or leukemia

Cancer of lymphatic or blood origin

Adenoma

Benign glandular tumor

Adenocarcinoma

Malignant glandular epithelial tumor

Tumor grade

Based on microscopic appearance and differentiation

Tumor stage

Classification based on tumor size and degree of spread

Grade 1 tumor

Well differentiated, low mitotic index, modest abnormalities

Grade 5 tumor

Poorly differentiated, high mitotic index, gross abnormalities

Stage 1 tumor

Small tumor with no spread

Stage 5 tumor

Large tumor metastasized to remote organs

Density-dependent inhibition

Normal cells stop dividing when surrounded by neighboring cells

Tumor cells and response to local signals

Tumor cells may lose the ability to sense neighboring cells

Contact inhibition

Normal growth suppression caused by contact with surrounding cells

Substrate-dependent growth

Normal cell division depends on proper attachment to the extracellular matrix

Telomere

Specialized DNA sequence at chromosome ends

Telomere shortening

Occurs with repeated cell division and limits cell lifespan

Cell senescence

State in which a cell remains alive but stops dividing

Telomerase

Enzyme that maintains telomeres

Telomerase

Active in about 85% of cancers

Cyclin-CDK complex

Protein complex that promotes cell cycle progression

Restriction point

Major checkpoint controlling the G1 to S transition

Rb

Protein that helps restrain progression through the G1 to S checkpoint

DNA repair

Systems that correct DNA damage and mutations

BRCA1

Protein involved in DNA repair

Loss of BRCA1 function

Leads to faulty DNA repair and mutation accumulation

Apoptosis

Programmed cell death that removes unnecessary or dangerous cells

Loss of apoptosis

Allows damaged cells to survive and continue evolving

Angiogenesis

Formation of new blood vessels

Tumor angiogenesis

New blood vessels supply the tumor and promote growth invasion and metastasis

VEGF

Factor that promotes angiogenesis

Proteases

Enzymes cancer cells use to break down surrounding tissue during invasion

Chemoattractants

Signals that encourage cancer cells to move

Tumor microenvironment

Local tissue conditions that influence tumor survival and growth

Prostate cancer metastasis pattern

Favors the bone microenvironment

Osteoclast

Cell that breaks down bone

Osteoblast

Cell that builds bone