• Kayla Hui

Targeted Cancer Therapies

In 2020 an estimated 1,806,590 new cases of cancer were predicted to be diagnosed in the United States, from this, about 606,520 people will die from cancer. Cancer is among the leading causes of death worldwide. Due to its terrifying prospect, there have been many cancer therapies being developed. Since 1946 the United States has invested more than 5 million dollars in research grants for cancer research. Through these extensive studies, another possible treatment has arisen, which is targeted cancer therapies.

Targeted cancer therapies, also known as molecularly targeted drugs, are drugs or other substances that can block the growth and spread of cancer by interfering with their “molecular targets”. These specific molecules are involved in the growth, progression, and spread of cancer.

Targeted therapies work through attacking specific areas or substances in cancer cells or they can detect and block chemicals that encourage cell growth. Targeted therapy may also change the proteins within the cancer cells resulting in cell death. Another form of targeted therapy is that they can carry toxins to only the cancer cells. Targeted cell therapies can also block the formation of blood vessels which can nourish the cancer cells. Due to their possibilities, targeted therapies are currently the focus of much cancer treatment drug development, along with precision medicine.

Precision medicine is an emerging form of medicine that encourages customizing health care through the use of knowledge of an individual's DNA and proteins. Precision medicine also takes into account the environment and lifestyle. It is hoped that precision medicine will also help to predict more accurately which treatment and prevention strategies will work in which individual.

There are a variety of types of targeted therapies. Angiogenesis inhibitors are an example of targeted therapies which block the formation of new blood vessels which are used to “feed” the cancer cells. These targeted therapies are important since it has been proven to slow or stop tumor growth without killing the cancer cells over a long period of time. For this reason, they are typically most effective when combined with additional therapies.

Another type of targeted therapy is monoclonal antibodies; these are immune system proteins created in a lab. They deliver molecules by themselves or molecules with drugs into or onto the cancer cell to kill it. Some monoclonal antibodies are also considered a form of immunotherapy since they are used to turn the immune system against cancer. Monoclonal antibodies can do this by marking cancer cells for the immune system to recognize and destroy them. As an interesting side note, monoclonal antibodies are also currently being used as a treatment for COVID-19, they are directed against the spike protein of the SARS-CoV-2. It is used to block the virus’ attachment and entry into human cells.

Proteasome inhibitors are another form of targeted cell therapy, they focus on disrupting normal cell functions causing the cancer cells to die. Proteasomes are protein complexes that cleave cellular proteins into peptides.

The fourth type of targeted cancer treatment to be used is signal transduction inhibitors. Signal transduction inhibitors disrupt cell signals to change the actions of the cancer cells. Signal transduction inhibitors block signals passed from one molecule to another inside a cell, this can impact multiple functions such as cell division and cell death.

Targeted therapies vary from standard chemotherapy in that they only act on the specific molecular targets which are associated with cancer instead of all rapidly dividing normal and cancerous cells. This is an improvement since chemotherapy attacking all rapidly dividing cells often leads to detrimental side effects such as hair loss, easy bruising and bleeding, and anemia. Targeted therapies are also often cytostatic in that they block tumor cell proliferation. Usually, chemotherapy agents are cytotoxic, meaning they kill tumor cells.

Overall, targeted cell therapies hold much promise for the future of cancer treatment. Targeted cell therapies also show the beginning of the use of precision medicine which is likely to have increased value in many different fields. I hope you join me in watching the future development of this innovation! As always, thank you for listening!