Circulating tumor cells (CTCs) are those cells that break away from a primary tumor and spread to distant organs via the bloodstream to create secondary tumors. This process, called metastasis, is the deadly phase of cancer as these secondary tumors interrupt normal organ function and consume valuable nutrients. Currently, metastasis is determined when secondary tumors, comprised of millions of tumor cells, are at least several millimeters in diameter and are seen using MRI or CT scans. We detect CTCs at the single cell level in blood samples of patients long before these cells create deadly tumors. We have created a flow system that tests blood samples for CTCs by blasting them with laser light that induced high frequency ultrasonic responses. These ultrasonic responses are unique to CTCs and indicate that cancer has begun to spread. By counting the cells, we can track the patient's response to therapy, determine remission, and detect relapse.
Our flow system accepts a 5 ml sample of blood and is separated into a train of microdroplets, each of which is irradiated by our laser. Droplets containing only normal blood cells are discarded. Those droplets that contain CTCs emit unique, high frequency sound waves and are separated for laser analysis. The number of CTCs in a sample is determined by the number of ultrasonic responses.
In this project, we will obtain a micromanipulator to grab individual cells from the CTC containing droplets, so that testing can be performed on single CTCs.
CTCs are very rare cells, occurring about one among a billion or more normal blood cells. Our system allows us to identify and capture these rare cells so that they can be studied. By studying these cells using molecular and genetic tests, not only can we tailor treatment options to the patient, but cancer biologists can gain deeper knowledge of metastatic disease. Scientists will be able to look into these spreading cancer cells and perhaps learn what mutations and other factors cause these cells to proliferate. The Holy Grail of such research is to find the molecular switch in these cancer cells that allows them to spread throughout the body. This switch, once identified, will be turned off.
I am an Associate Professor of Biological Engineering and Dermatology at the University of Missouri (MU). I have been investigating problems in biomedical optics for almost twenty years, with practical application in dermatology, surgery, oncology, pathology, ophthalmology, and other fields of medicine. I have a Ph.D. in Electrical Engineering from Oregon Health & Science University, where I began studying photoacoustics, or laser induced ultrasound. At MU, I collaborate with many scientists and clinicians in order to develop my photoacoustic flowmeter for clinical use.
I want to thank all of our backers who gave us great momentum to achieve 11% of our goal after only five days! I'd also like to clarify some issues regarding our rewards:
1. For the $500 pledge, we will capture a single red blood cell for you. If your sample reaches us within a week, there will be enough viable cells to capture, so overnight courier is not required. Alternatively, if you do not want to send your own blood, I will be happy to send you one of my own red blood cells embeded in the plastic block.
2. Also, for $250 and up (including our $500 backers) we will acknowledge you by name in future publications that contain results using the micromanipulator system. We expect to publish such results in journals such as the Journal of Biomedical Optics, Lasers in Surgery and Medicine, or Physics in Medicine and Biology, where we have previously published many papers.