Oncology Nursing: Biology of Normal and Abnormal Cells

This is a nursing lecture review about 'Biology of Normal and Abnormal Cells'


Understanding Terms

• Hypertrophy - cells increase in SIZE
• Hyperplasia - cells increase in NUMBER
• Neoplasia - increase in new growth of cells that are NOT NEEDED
• Anaplasia - group of cells without specific shape or differentiation

Pathophysiology of Cancer

In understanding the pathophysiology of Cancer, we must first understand the characteristics of both normal and abnormal cells.

BIOLOGY OF NORMAL CELLS

• Limited Cell Division
• Cells only divide because of 2 REASONS
• to develop NORMAL TISSUE
• replace lost or damage NORMAL TISSUE

• Undergo Apoptosis
• Apoptosis - capability of a cell to die on its own. Program Cell Death!

• Shows specific morphology
• It means NORMAL CELLS shows specific CELL STRUCTURE

• Has small nuclear-cytoplasmic ratio
• The CYTOPLASM must be greater in size than the NUCLEUS

• Performs SPECIFIC FUNCTION

• Adhere tightly together
• Cells adhere together due to the protein "FIBRONECTIN"
• Fibronectin is not present in blood cells (RBC, WBC, Platelets)

• Are non-migratory (except blood cells)

• Grow in an orderly and  well regulated manner
• G0 - resting stage of cells
• G1 - increase in nutrients and energy. Increased amounts of cytoplasm
• S - DNA Synthesis
• G2 - protein synthesis
• M - Mitosis
• Prophase
• Metaphase
• Anaphase
• Telophase

• Contact-inhibited
• Once cells multiply and have a direct contact with each other, the multiplication process will STOP!

• Euploid
• Meaning ~ EACH NORMAL CELLS must contain 23 CHROMOSOMES ONLY!

BIOLOGY OF ABNORMAL CELLS

A. BENIGN TUMOR CELLS -These are NORMAL CELLS growing in the WRONG PLACE and TIME.

Example: Moles, Uterine Fibroid Tumor, Skin Tag, Endometriosis, Nasal Polyps

• Continuous INAPPROPRIATE Cell Growth
• Shows SPECIFIC MORPHOLOGY
• SMALL nuclear-cytoplasmic ratio
• Perform SPECIFIC functions
• ADHERE tightly together
• NON-MIGRATORY
• Grow in an ORDERLY MANNER
• EUPLOID

B. CANCER CELLS - (malignant) ABNORMAL CELLS with NO USEFUL FUNCTION; harmful to normal body tissues

• Have RAPID or CONTINUOUS CELL DIVISION
• DO NOT RESPOND TO APOPTOSIS
• Cancer cells have LONG TELOMERES and has a lot of enzyme TELOMERASE which maintains TELOMERIC DNA
• Which makes these cells "IMMORTAL"
• ANAPLASTIC Morphology
• LARGE Nuclear - Cytoplasmic Ratio
• LOSE Some functions
• CANCER CELLS SERVE NO USEFUL PURPOSE
• ADHERE LOOSELY
• Able to MIGRATE
• ABLE TO METASTASIZE
• Grow by INVASION
• NOT CONTACT INHIBITED
• Are ANEUPLOID
• Has more than or less than 23 chromosomes

Reference: Workman (2006). Altered Cell Growth and Cancer Development, Medical-Surgical Nursing, Volume 1 5th Edition, 467-472 

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