Monoclonal antibodies

With monoclonal antibodies, antibodies means that they target a specific antigen on the cell surface with an antibody-antigen binding; and monoclonal means that each antibody is produced from a specific B cell line consisting of identical B cells.

Okay, now monoclonal antibodies are used for the treatment of cancer and various autoimmune diseases like multiple sclerosis and rheumatoid arthritis.

In this video, we are focusing on the monoclonal antibodies that are used for cancer.

Normally, all of our cells grow and divide through a tightly regulated cell cycle once they receive growth factor signals.

During the cell cycle, if a cell appears abnormal in any way to the immune cells that do constant surveillance, the cell has to fix the problem or undergo apoptosis, or programmed cell death - a bit like cellular suicide, rather than proceed to the next phase of the cell cycle.

But cells can become mutated due to environmental or genetic factors.

A mutated cell becomes cancerous when it starts to divide uncontrollably.

As cancer cells start piling up on each other, they form a small tumor mass and they need to induce blood vessel growth, called angiogenesis, to supply themselves with enough energy.

Some tumors produce vascular endothelial growth factor, or VEGF, which binds to VEGF receptors found on vascular endothelial cells and stimulates angiogenesis.

Also, many tumors overexpress growth factor receptors like the epidermal growth factor receptor, or EGFR, and the human epidermal receptor 2, or HER2, that stimulate cell proliferation and tumor growth.

Malignant tumors are ones that are able to break through the basement membrane.

Some of these malignant tumors go a step further and detach from their basement membrane at the primary tumor site, enter nearby blood vessels or the lymphatic system, and establish secondary sites of tumor growth throughout the body—a process called metastasis.

Now, the monoclonal antibodies that are used for the treatment of cancer target specific antigens that are usually overexpressed on the surface of cancer cells.

Once these antibodies bind to the surface of cancer cells, they can trigger apoptosis, promote the formation of MAC complexes which trigger complement-mediated cell lysis, or attract other immune cells to attack the cancer cells.