Cancer, also called malignancy, is an abnormal growth of cells. Cancer is more than 100 types, including breast cancer, skin cancer, lung cancer, colon cancer, and lymphoma. Cancer cells are uncontrolled division of cells.
Conversion of normal cell into cancerous cell is called transformation. And the cell is called transformed cell. It is a multifactorial disease condition.
A tumor develops through repeated rounds of mutation and proliferation, giving rise eventually to a clone of fully malignant cancer cells (2 types of tumors, mainly malignant and benign tumor). At each step, a single cell undergoes a mutation that either enhances cell proliferation or decreases cell death.
WHAT ARE NORMAL CELLS
- Normal cells are the regular body cells whose growth and division are under control.
- They represent millions of cells in the body that are organized into tissues. These cells perform unique functions based on their tissues.
- They have specific shape and size.
- A specific type of stem cells produce immature, normal cells that are tissue-specific.
- The immature cells become mature by processes known as differentiation and specialization.
- The cell cycle of normal cells has to pass through Various checkpoints. If the cells are unable to perform the functions required by any of these checkpoints, these cells forced to die.
CHARACTERS OF CANCER CELLS
- Cancer cells stimulate their own growth (self-sufficiency in growth signals).
- Cancer cells are insensitive to anti-growth signals, i.e. they resist inhibitory signals that might otherwise stop their growth.
- Cancer cells resist apoptosis.
- In cancer the cell growth is uncontrolled or density independent growth.
- Angiogenesis- Cancer cells stimulate the growth of blood vessels to supply nutrients to tumors.
- Cancer cells perform tissue invasion and metastasis, i.e. they invade local tissue and spread to distant sites.
- Loss of contact inhibition: Contact inhibition is a regulatory mechanism that functions to keep cells growing into a layer one cell thick, i.e. a monolayer. The cell replicates rapidly and moves freely. This process continues until the cells occupy the entire substratum. At this point, normal cells typically lose this property and thus divide and grow over each other in an uncontrolled manner.
- CARCINOMA: This type of cancer starts in skin or tissue or affect this area.
- SARCOMA: This type of cancer affect Connective tissues ( blood vessels, muscles, cartilage, bones).
- LEUKEMIA: Affect White Blood Cells, bone marrow, low immune system.
- LYPHOMA: Affect Lymphocytes, low immune response.
CANCER CELL CHANGES:
There are mainly three kind of changes which take place in normal cells to become cancerous:
- Biochemical changes
- Cytoskeleton changes
- Cell surface changes
DIFFERENCE BETWEEN NORMAL CELLS AND CANCER CELLS
There are many significant differences between cancer cells and normal cells. Cancer cells keep dividing, they grow too rapidly to mature, they may influence the normal cells. Cancer cells are invasive, i.e. it may spread to other parts of the body.