Recent clinical trials utilizing autologous dendritic cells for the treatment of early stage breast cancer (ductal carcinoma in situ; DCIS) induced strong immune responses characterized by production of Th1 cytokines including Interferon-gamma (IFN-γ). About 30% of vaccinated subjects showed complete regression of tumor by the time of surgery. Follow-up in vitro studies showed that two principal Th1 cytokines, IFN-γ and TNF-α, were capable of inducing apoptosis in breast cancer cell lines, thus suggesting that Th1 cytokines are at least in part responsible for the tumor regression seen in vivo. Furthermore, recent data shows that combinational therapy using small-molecule inhibitors could enhance Th1 mediated cell death in breast cancer. Thus, we hypothesized that simvastatin, a HMG-CoA reductase inhibitor that also interferes with Ras oncogene activity, could enhance the apoptotic effect of Th1 cytokines in pancreatic cancer cell lines. Each cell line was cultured either without treatment, with cytokines only, with simvastatin only, or with both for 3 days. Metabolic activity via the Alamar Blue assay, vital staining with Trypan Blue, and Flow cytometry-based apoptotic cell death assays indicated strong additive effects between cytokines and Simvastatin.
Investigating Chemical Stress and Antibiotic Sensitivity of Escherichia coli and Staphylococcus epidermidis03/11/2015
Previous lab work has investigated the effects of thermal stress and antibiotic sensitivity on bacteria used in microbiology teaching labs concentrating on Pseudomonas fluorescens. This investigation, however, focuses on how chemical stress affects the antibiotic sensitivity of two common laboratory strains: Escherichia coli and Staphylococcus epidermidis. Literature searches revealed that potassium acetate is a common additive in sporulation media. Using the Kirby Bauer procedure – a technique used in clinical labs to characterize antibiotic sensitivity of clinical isolates – we studied how the addition of sodium chloride, potassium chloride, sodium acetate and potassium acetate to growth media affects the sensitivity of E. coli and S. epidermidis. After measuring zones of inhibition created by the antibiotic disks, we found that sodium and potassium acetate increased the sensitivity of the two bacteria significantly, while sodium and potassium chloride had negligible effects. Further studies will characterize the relationship between acetate and potential antibiotic sensitivity.