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What is a Parp Inhibitor?

Mary McMahon
Mary McMahon
Mary McMahon
Mary McMahon

A parp or PARP inhibitor is an antineoplastic drug that works by interfering with the DNA repair process in cancerous cells. Drugs in this class can be used alone or with other chemotherapy agents. As of 2011, parp inhibitors were primarily investigational drugs, with researchers studying their potential applications in laboratory and clinical trial environments. This drug class has considerable appeal to cancer researchers and doctors, as it can attack cancers without damaging neighboring cells in the body.

Poly(ADP-ribose) polymerase (PARP) is an enzyme involved in the process of DNA repair. Every time cells multiply and divide, there is a risk of DNA damage, addressed with built-in repair systems. Certain types of tumors rely heavily on the parp enzyme to repair themselves. These tumors can be vulnerable to targeting with agents designed to lock onto the enzyme. A parp inhibitor interferes with this process, killing the cancer cells by making it impossible to repair their DNA. The dead cells cannot replicate and the tumor will stop growing and eventually start shrinking as cells die off.

A parp inhibitor can be used to eradicate cancer cells by making it impossible for them to replicate.
A parp inhibitor can be used to eradicate cancer cells by making it impossible for them to replicate.

When used alone, a parp inhibitor can attack a cancer without damaging cells near the cancer, as it does not target healthy cells, only cancer cells relying on parp for DNA repair. It can also be used with another chemotherapeutic agent, mopping up after the other drug to kill cancer cells the first drug is unable to reach. Combination therapy can be highly effective in cancer treatment by attacking a cancer from multiple angles.

Many chemotherapy regimens can be grueling for patients to endure.
Many chemotherapy regimens can be grueling for patients to endure.

A parp inhibitor is not effective on all types of cancers. Cancer cells are highly diverse and some do not rely heavily on this enzyme for DNA repair, making them unsuitable targets for drugs in this class. Research on these drugs has shown them to be effective for treatment of some breast cancers, including breast cancers without susceptibility to other common drug targets, like human epidermal growth factor receptor 2 (HER-2).

Chemotherapy involves introducing various chemicals into the body in an effort to kill cancer cells.
Chemotherapy involves introducing various chemicals into the body in an effort to kill cancer cells.

Preliminary studies on parp inhibitor drugs showed promise, leading researchers to express excitement about the potential applications of these medications. The lack of cytotoxicity to healthy cells is a particularly important trait for cancer medications. Many chemotherapy regimens are grueling for patients, and can come with considerable complications and side effects. These can potentially endanger patients, as well as making it harder for patients to comply with prescribed treatments. Medications capable of targeting cancer cells only and leaving healthy cells alone represent a new generation of cancer drugs.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a WiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...
Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a WiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...

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    • A parp inhibitor can be used to eradicate cancer cells by making it impossible for them to replicate.
      By: adimas
      A parp inhibitor can be used to eradicate cancer cells by making it impossible for them to replicate.
    • Many chemotherapy regimens can be grueling for patients to endure.
      By: Photographee.eu
      Many chemotherapy regimens can be grueling for patients to endure.
    • Chemotherapy involves introducing various chemicals into the body in an effort to kill cancer cells.
      By: nebari
      Chemotherapy involves introducing various chemicals into the body in an effort to kill cancer cells.
    • Chemotherapy drugs are highly toxic, and may cause hair loss in some patients.
      By: prudkov
      Chemotherapy drugs are highly toxic, and may cause hair loss in some patients.