Cancer is one of the few diseases that we cannot defeat yet. However, breakthroughs in cancer treatment have appeared one after another, making the “undefeatable” disease less scary.
A new class of drugs were developed by scientists recently, which could stop cancers developing treatment resistance.
Cancer treatment resistance
As the name suggests, cancers have the ability to develop resistance to traditional therapies. For example, although many types of cancers are initially susceptible to chemotherapy, over time they can develop resistance through these and other mechanisms, and the previous treatment no longer has effect, or has a largely declined effect on cancer.
Because of this, treatment resistance is considered a serious problem in cancer therapy and a major barrier to improving survival for many patients.
The situation makes it important to invent new drugs that stops cancer treatment resistance developing, which is what scientists have recently done.
The APOBEC3 enzyme family
The developed new class of drug blocks an enzyme in cancer cells that is responsible for the cancers evolving treatment resistance when exposed to drugs.
The enzyme is called APOBEC3B. according to Professor Vyacheslav Filichev, the enzyme can mutate DNA, which can change the cancer cells into different forms. Although the forms are not “designed” to resist the treatment, some of them can luckily escape from the immune response and resist drugs. These cells then survive and proliferate.
The enzyme APOBEC3B belongs to an enzyme family called APOBEC3.
In a healthy person, he family of enzymes fight off pathogens by mutating their DNA, making them unable to cause infection.
In cancer cells, however, the APOBEC3 enzymes help them evade the immune system and develop resistance to treatment.
The new class of drug
APOBEC3B is a major source of genetic mutations in multiple cancers, including breast, bladder, cervical, lung, ovarian and head and neck cancers, which makes it the key to blocking cancers’ resistance to treatment.
Luckily, APOBEC3B is not an essential part of the body’s immune response, while the rest of the APOBEC3 family is essential for proper immune function. This gives scientists a chance. It’s possible to selectively inhibit APOBEC3B and, at the same time, avoid unwanted side effects in patients.
Further steps to go
The scientists have established methods to selectively inhibit the APOBEC3B enzyme using chemically modified DNA molecules, the remaining question being more powerful inhibitors are to be developed.
Although scientists still have a way to go before applying the new class of drugs in clinical trials, this is a big step toward successful cancer treatment. I think within most of our lives, cancer can be completely cured by modern medical technologies.