Functional Characterization of Circulating Tumor Cells

We recently published a paper in PLoS One (go here) about functional characterization of prostate circulating tumor cells.  This work was the product of many people’s efforts, including Erica, Jason, Jim, and Steven in our group–Erica did chip design and fab and SOP development, Jason did initial surface chemistry characterization and capture experiments, Jim did CFD analysis, and Steven characterized prostate cell adhesion parameters.

The point of this paper was to show that we can capture prostate circulating tumor cells by use of a prostate-specific (rather than pan-epithelial) antibody–this is important because the antibodies to epithelial markers (e.g., EpCAM) may suffer when cells undergo epithelial-to-mesenchymal transition as part of the metastatic process.  Also, we showed that we can characterize cells functionally, meaning that we see how the living cells

A circulating prostate cancer cell stained to show the nucleus (upper left), tubulin (upper right), and PSMA (lower left). The bundled tubulin seen at upper right is indicative of drug-target engagement when taxane chemotherapy is used.

respond to their environment, in contrast to the (much more common) enumeration of cells or characterization of genetic material.

We are now looking forward to applying these techniques in clinical trials, with the hopes of proving that functional characterization on microdevices is a better way of predicting which patient should be on which chemotherapy regimen.

243rd ACS National Meeting

Recently I attended the 243rd ACS National Meeting in San Diego, California, from March 25th to 29th. While there, I gave an oral presentation describing my recent progress in the dielectric measurement of algal lipid content as part of the “Challenges in Algal Biofuels: Biochemistry, Lipid Extraction and Analysis” session.

As described in the algae project page, we are developing a method to rapidly measure the lipid content of algae cells in suspension using dielectric spectroscopy. The ability to measure lipid content in real time will improve the productivity of algal biofuel feedstocks by allowing algae growers to respond to changing environmental conditions and even utilize   environmental stresses like nitrogen starvation to increase lipid output. In this presentation, I described our initial dielectric characterization of algae with a range of lipid contents.

The algal biofuel session was an excellent overview of recent progress in algal biofuel production. Presentation topics included FTIR (Fourier transform infrared) spectroscopy of algae samples, methods for avoiding culture contamination during industrial production, and programs to train the future algal biofuel workforce. Outside of the algal biofuels session, Prof. Carolyn Bertozzi from UC Berkeley gave a fascinating keynote lecture on Bio-orthogonal functional groups for labeling sugars and proteins inside of living systems. Other highlights included a presentation on whispering-gallery mode arrays for extremely sensitive detection of biomolecules, a number of presentations on processes converting algal biomass to biofuels, a poster on exploiting spherical aberrations for rapid autocorrelation of lasers, and a poster by by Pat Coller from Oak Ridge National Lab on chemical reactions resulting from the merger of microscale water droplets. Overall, attending and presenting at the ACS meeting was a rewarding experience which I plan to repeat in the future.