Doctors have often chosen chemotherapy as a treatment option for cancers. The procedure involves the use of drugs, like cisplatin, to cause the death of cancer cells. However, it has been discovered that this treatment procedure is less effective for head and neck cancers, as the cells of these cancer types have been able to gain immunity against these drugs. In the majority of the treatment of patients with head and neck cancers, the choice of doctors to employ this procedure fails due to this reason.
This has made scientists go into research to uncover how the cells of these cancer types can do this. Thanks to the scientists at the University of Pittsburgh and UPMC, a clear picture of how this occurred has now been identified.
What went wrong?
Research showed that TMEM16A is the protein responsible for the increased resistance to the drug – cisplatin – by the cells. Scientists found that this protein is usually “over-expressed” in about 30% of people with head and neck cancers.
TMEM16A is a member of the ion-channel proteins – proteins that creates the pathway for the transport of ions across cells. TMEM16A specifically provides the pathway needed for the movement of chloride ions across cell membranes, to enable regulation of muscular and nervous activities, and movement of salt and water – it does this by covering the membrane of cells. This process is important to prevent neurological and kidney impairments such as cystic fibrosis, kidney stones, and epilepsy, so the scientists were taken aback when they found out that this protein influences the immunity of the cancer cells to chemotherapy.
How do these cancer cells do this?
The expression of TMEM16A in the body of a patient suffering from head and neck cancer leads to increased production of lysosomes (that function as the cleansing organelle of cells) in the body which attack cisplatin whenever the patient undergoes chemotherapy, thereby, making the procedure less effective.
After this discovery, the scientists decided to test the effect of the malaria drug – hydroxychloroquine – on the activity of this protein, since the drug is known to hinder lysosomes from carrying out their functions.
The big discovery
They carried out the test using fertilized chicken eggs and mice. First, they divided both specimens into three groups and inserted cancer cells from humans who had head and neck cancer into each group. Next, they treated the first group of each specimen with hydroxychloroquine only, the second with cisplatin only, and the third with both hydroxychloroquine and cisplatin.
At the end of the test, they recorded the following results: the group of specimens (mice and eggs) that were treated with both drugs showed an increased rate of dysfunction of cancer cells than those that were treated with either one of the drugs only.
The team was happy about the results and is currently working to improve on it to make it clinically safe for humans.
People with head and neck cancers can now be treated effectively via chemotherapy, therefore, improving the quality of life of these people.
This study has created a new approach to chemotherapy treatment procedures of head and neck cancers. Now, doctors and oncologists can successfully treat patients with this cancer type.