Novel method of treating lung cancer found

Lung cancer is one of the leading cancers affecting both men and women. As the cancer spreads rapidly to other distant body parts, apart from surgery, chemotherapy also forms an important part of the treatment. But as the drugs used in chemotherapy are generally very toxic, they damage organs and cause multiple side effects when administered intravenously. Now, researchers have developed a novel method of administering these chemotherapy drugs- through inhalation. The method has been described in the recent issue of the Journal of Controlled Release.

The latest technique targets just the cancer cells. Unlike intravenously administered chemotherapy drugs which suppress the tumor, this new technique could eliminate the cancer cells completely in an animal model. Moreover, unlike intravenously administered chemotherapy drugs, this system of drug delivery ensures that the drug reaches the target organ in a more intact form.

The cancer cells offer two forms of resistance namely: pump resistance, which pumps out the chemotherapy drug out of the cancer cells with the help of MRP1 mRNA, and non-pump resistance exerted through BCL2 mRNA which protects the cancer cells from dying. The new drug delivery system consists of five main components:

•A nanostructured lipid carrier system wherein the lipid nanoparticles are easily inhaled and get attached to the cancer cells.    

•Small interfering RNA (siRNA) against pump resistance.

• siRNA against non-pump resistance Chemotherapy drug which could be either doxorubicin or paclitaxel.

•A synthetic form of luteinizing hormone-releasing hormone (LHRH) which gets attached to specific receptors on the surface of lung cancer cells.

The system was checked in vitro on human cancer cells and in vivo using a mouse model of lung cancer. After inhalation, the lipid carrier system delivered the drugs and the siRNAs into the lung cancer cells while not affecting the healthy cancer cells. Therefore, the systemic side effects of intravenously delivered chemotherapy drugs were minimized. The researchers observed that anti-tumor activity through this mode was more compared to intravenous therapy. The lung cancer in the mouse was completely eliminated. 

The researchers have already applied for a patent for this inhalation route of chemotherapy and are conducting further experiments so that the technique is perfected for human use.

Reference:

Editor: Dr. Bimal Rajalingam MBBS DNB (Resp Med)

Date: 
Tuesday, June 18, 2013
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