SINGAPORE - Singapore scientists have developed a miniaturised biochip for investigating the effect of drugs on cancer stem cells (CSCs), paving the way for the development of more effective cancer drugs.
In a tumor, CSCs form a small and distinct class of cancer cells that are more resistant to chemotherapy.
Similar to stem cells found in human tissues, CSCs can produce and differentiate into different cell types. Thus, if CSCs are not eradicated, they can repopulate the tumour and lead to cancer recurrence.
Hence, it is important for researchers to understand the efficacy of anti-cancer drugs against CSCs.
However, since CSCs are so scarce - they make up approximately 1 per cent of cancer cells - their study has been hampered by conventional drug screening methods, which require large sample volumes and are slow and expensive.
A team of researchers from the Institute of Bioengineering and Nanotechnology (IBN), the world's first bioengineering and nanotechnology research institute, has developed a technology called the Droplet Array to perform cheaper, faster and more convenient drug screening using limited samples.
In traditional biological assays, microplates - a flat plate with multiple wells in which samples are placed - are commonly used, and each well requires at least 2,500 or 5,000 cells, to be present for viable analysis.
By comparison, IBN's Droplet Array is a flat, rectangular glass plate on which a series of spots, each 2 millimeters in diameter, are arranged.
Each spot requires only 500 cells for screening. This massive reduction in sample volume not only saves money, but is also particularly advantageous for studying scarce quantities of target cells, such as CSCs.
Using this technology, the team analysed the CSCs extracted from breast, liver and colon cancer cells.
It was found that chemotherapeutic drugs such as doxorubicin, which usually induce cell death in liver cancer cells, demonstrated poor efficacy in liver CSCs. The CSCs from the breast and colon tumors also showed much greater ability to survive the effects of anti-cancer drugs.
The drug resistance properties of CSCs have been widely discussed in recent years but until now, it has been challenging to quantify this correlation.
Using the Droplet Array, IBN researchers have successfully demonstrated that CSCs can survive chemotherapy and drive metastasis.
Lead researcher Professor Jackie Y. Ying said the discovery helps accelerate drug screening and development, and that the team hopes that it will facilitate the development of more effective cancer drugs.
The miniaturized biochip is compatible with existing laboratory instruments, such as plate readers and microscopes, and reduces the set-up cost and the need to purchase additional equipment when adapting to this new technology.