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Understanding Cancer and Related Topics

Understanding Cancer

Developed by: Lewis J. Kleinsmith, Ph.D., Donna Kerrigan, M.S., Jeanne Kelly, Brian Hollen

•Illustrate what cancer is•Explain the link between genes and cancer•Discover causes, detection and diagnosis techniques

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Decide with your partner

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What Is Cancer?

• In your own words, create a definition for cancer.

• Cancer - A disease in which abnormal cells divide uncontrollably and destroy body tissue

(mayoclinic.com)

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Different Kinds of CancerCancer can originate almost anywhere in the body

Lung

Breast (women)

Colon

BladderProstate (men)

Some common sarcomas:Fat

Bone

Muscle

Lymphomas:Lymph nodes

Leukemias:Bloodstream

Some common carcinomas:

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Naming Cancers

Prefix Meaning

adeno- gland

chondro- cartilage

erythro- red blood cell

hemangio- blood vessels

hepato- liver

lipo- fat

lympho- lymphocyte

melano- pigment cell

myelo- bone marrow

myo- muscle

osteo- bone

Cancer Prefixes Point to Location

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DogsTell your partner where the cancer, myeloma, will be located.

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Loss of Normal Growth Control

Cancer cell division

Fourth orlater mutation

Third mutation

Second mutation

First mutation

Uncontrolled growth

Cell Suicide or Apoptosis

Cell damage—no repair

Normal cell division

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Example of Normal Growth

Cell migration

Dermis

Dividing cells in basal layer

Dead cells shed from

outer surface

Epidermis

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The Beginning of Cancerous Growth

Underlying tissue

• During the development of skin cancer, the normal balance between cell division and cell loss is disrupted. The basal cells now divide faster than is needed to replenish the cells being shed from the surface of the skin.

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Think – Pair – Share

• What is the difference between normal cell division and cancer cell division?

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Tumors (Neoplasms)

Underlying tissue

• The gradual increase in the number of dividing cells creates a growing mass of tissue called a tumor (neoplasm)

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HORSESExplain to your partner how a tumor is formed.

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Invasion and Metastasis

3Cancer cells reinvade and grow at new location

1Cancer cells invade surrounding tissues and blood vessels

2Cancer cells are transported by the circulatory system to distant sites

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Malignant versus Benign Tumors

Malignant (cancer) cells invade neighboring tissues, enter blood vessels, and metastasize to different sites

Time

Benign (not cancer) tumor cells grow only locally and cannot spread by invasion or metastasis

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Why Cancer Is Potentially Dangerous

Melanoma cells travel through bloodstream

Melanoma(initial tumor)

Brain

Liver

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Genes and Cancer

Chromosomes are DNA molecules

Heredity

RadiationChemicals

Viruses

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DNA Structure

DNA molecule

Chemicalbases

GC

TA

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THINK – PAIR - SHARE

• What are the different types of mutations possible for DNA?

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DNA Mutation

Additions

Deletions

Normal gene

Single base change

DNA

CT

A G C G A A C TAC

A G G C G C T AAC A C T

A G C T A A C TAC

A G A A C TAC

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Proto-Oncogenes and Oncogenes

Mutated/damaged = oncogene

Oncogenes accelerate cell growth and division

Cancer cell

Normal cell

Normal genes regulate cell growth

Proto-Oncogenes – genes that could lead to unregulated cell growth/reproduction if damaged

Oncogenes - damaged proto-oncogenes

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Proto-Oncogenes and Normal Cell Growth

Receptor

Normal Growth-Control Pathway

DNA

Cell proliferation

Cell nucleus

Transcriptionfactors

Signaling enzymes

Growth factor

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Oncogenes areMutant Forms of Proto-Oncogenes

Cell proliferation driven by internal oncogene signaling

Transcription

Activated gene regulatory protein

Inactive intracellular signaling protein

Signaling protein from active oncogene

Inactive growth factor receptor

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Tumor Suppressor Genes

Normal genes prevent cancer

Remove or inactivate tumor suppressor genes

Mutated/inactivated tumor suppressor genes

Damage to both genes leads to cancer

Cancer cell

Normal cell

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Tumor Suppressor GenesAct Like a Brake Pedal

Tumor Suppressor Gene Proteins

DNACell nucleus

Signalingenzymes

Growth factor

Receptor

Transcriptionfactors

Cell proliferation

Tumor Suppressor Genes - genes that instruct cells to produce proteins that restrain cell growth and division

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p53 Tumor Suppressor ProteinTriggers Cell Suicide

Normal cell Cell suicide(Apoptosis)

p53 protein

Excessive DNA damage

In cells that have undergone DNA damage, the p53 protein acts like a brake pedal to halt cell growth and division. If the damage cannot be repaired, the p53 protein eventually initiates cell suicide

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DNA Repair Genes

Cancer

No cancer

No DNA repair

Normal DNA repair

Base pair mismatch

T CATC

A GTCG

T CAGC

A GTCG

A GTG A GTAG

T CATCT CATC

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Cancer Tends to Involve Multiple Mutations

Malignant cells invade neighboring tissues, enter blood vessels, and metastasize to different sites

More mutations, more genetic instability, metastatic disease

Proto-oncogenes mutate to oncogenes

Mutations inactivate DNA repair genes

Cells proliferate

Mutation inactivates suppressor gene

Benign tumor cells grow only locally and cannot spread by invasion or metastasis

Time

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Mutations and Cancer

Genes Implicated in Cancer

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Design a comic strip with your partner. It should show the process of how a cell changes from having normal cell growth and reproduction to cancerous cell growth. You must include the following terms:

•Proto-Oncogenes•Oncogenes•Tumor Suppressor Genes•Apoptosis•Cell Cycle•Mutations•Uncontrolled Growth

Design an animated comic strip

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Cancerous cells vs. Noncancerous Cells

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Lung Cancer Cells

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Skin Cancer

Normal skin cell layers

Abnormal