Cancer

Cancer

The uncontrollable growth of cells in the body. There are 100 different types of cancer

Benign

Referring to a type of cancer that remains in one location and does not spread.

Malignant

This refers to a type of cancer that spreads to other parts of the body by invading neighboring tissue, entering blood vessel and metastasizing

Metastasis

The process by which cancer cells break loose from the tumour and spread to other areas of the body. Cancer cells break loose from tumour and spread

Tumor formation

The growth and development of abnormal cells that form a mass or lump.

Angiogenesis

The redirection of blood vessel growth by cancer cells provides the tumour with oxygen and nutrients.

Cell cycle

The series of events that a cell goes through as it grows and divides.

Carcinogens

Substances and agents that are known to cause cancer. Examples: chemicals, radiation, viruses

Proto-oncogenes

Genes that have a normal function but can turn into cancer-causing oncogenes when exposed to carcinogens.

Tumor suppressor genes

Genes that suppress tumor growth and prevent the development of cancer.

P53 gene

A tumor suppressor gene found in more than 50% of all cancers.

Genetic changes

Changes in DNA that can lead to the development of cancer.

Smoking

A cause of cancer due to the release of chemicals that can damage DNA and interfere with DNA repair.

Oncovirus

A virus that can cause cancer by inserting oncogenes or inactivating tumor suppressor genes.

Detection of cancer

Methods used to detect and diagnose cancer, such as physical exams, imaging scans like CT and MRI, biopsies, and DNA testing.

Strategies to fight cancer

Various approaches to treating cancer, including surgery, chemotherapy, radiation, vaccines, targeted therapies, immunotherapy, Active Immunotherapy, and radioimmunotherapy.

CRISPR technology

A gene-editing technology that can be used to edit cancer genes and potentially minimize cancer development.

Environmental carcinogens

Carcinogens in the environment that can induce mutations or change gene expression in humans and contribute to cancer development.

Healthy vs Cancer cells

Healthy

• Large cytoplasm

• single nucleus

• single nucleolus

• normal number of chromosomes and organized

• fine chromatin

Cancer

• small cytoplasm

• multiple nuclei

• multiple large and dark nucleoli

• course chromatin

• variation in size and shapes

• an abnormal number of chromosomes and disorganized

Healthy vs Cancer Cell Growth

Healthy

• cell anchors to the dish and divides

• when cells form a single layer they stop dividing (density-dependent inhibition)

• if some cells scrape away they divide to fill the gap and then stop when fill

Cancer

• they do not have density-dependent inhibition

• continue to grow which causes the tumour growth as long as it has enough nutrients

Feature of Cancer cells

Doesn’t response to signals that control the cell cycle, they have their own internal signals. Can be grown in a lab up to 25 years, normal cells die 1-2 years. G1 checkpoint does not stop cancer cells from diving through mitosis. Programmed cell death does not affect cancer cells. DNA has abnormalities, higher activities of tyrosine kinase.

Cancer and Cell Cycle Regulators

There are higher levels of cyclin in cancer cells, more cyclin means more cell division.

Causes of Cancer

Cancer is caused by mutation in segments of DNA that control the production of proteins. Everyone has pre-cancerous cells and continual irritation of these pre-cancerous cells triggers the development of cancer. 80% of cancers are caused by carcinogens. The other 20% are natural mutations.

Triggers of Cancer cells

Mutation in normal tumour-suppressive genes makes them less active. p53 genes are found in >50% of all cancers and Mutation of the proto-oncogene turns to cancer-causing oncogene causing cancer tumor cells to proliferate. Other mutations develop to result in >10% of cancers. In other people, mutation can accumulate over time to a greater extent

What causes genetic changes

Heredity, UV radiation, chemicals, viruses, smoking and cells dividing

Smoking and cancer

5000 chemicals released and enters our blood stream which affects our entire body. Chemicals can damage our DNA including genes that protect against cancer. Other chemicals cause damage by interfering with how cells repair DNA damage which can cause cancer

Cancer from X-rays, UV irradiation, pesticides, asbestos, formaldehyde, hair dyes, tobacco

Causes damage to DNA that is not repaired in time

Cancer from Virus Infection (oncovirus)

Accounts for 15% of all cancers. Hepatitis B causes liver cancer. Human Papilloma virus causes cervical. Epstein Barr virus causes lymphoma. These viruses may insert oncogene or inactive tumour-suppresive gene.

Cancer from Bacterial

Helicobacter pylori can cause stomach cancer

Cancer from excessive hormone levels

Higher estrogen can cause breast or cervical cancer and Higher testosterone can cause prostate cancer

Cancer from Genetic Inheritance

Some cancer are determined by genes that are inherited. BRAC 1 oncogene, inherited from mother

Surgery

remove tumor only if tumor has not metastasized

Chemotherapy

Kills rapidly dividing cells. Destroys spindle tubule formation but is non-specific and damage occurs to hair follicles, bone marrow and intestinal cells

Radiation

Kill tumors by damaging their DNA. Cancer cells cannot repair DNA damage as well as normal cells

Vaccines

For cervical cancer the HPV vaccines

Targeted therapies

Try and reduce growth of blood vessels towards tumors, reduce kinase activity levels through drugs of various types

Immunotherapy

Use the immune system to fight off cancer cells with specific recognition of antigens on the surface of cancer cells (tumor-associated antigen)

Active immunotherapy

Enhance the immune system to fight off cancer cells by adding interferon and interleukin (cytokines)

Removal of serum

Remove serum from blood that contains antibodies, purify them and add them back into the patient

Radioimmunotherapy

Attach radioactive isotopes to specific antibodies to deliver them directly to cancer cell to attach a drug to kill cell