Lidocaine downregulates Src Kinase Activity in Pancreatic Cancer in Vitro
Celine Macaraniag1, Jian Zhou1,2, Andrew Ta3, Valentina Valle4, Alexandra Barabonova3, Alain Borgeat4, Pier Giulanotti4, Gina Votta-Velis2,3,4, Ian Papautsky1,2
1Department of Biomedical Engineering, University of Illinois Chicago – Chicago, IL 2University of Illinois Cancer Center – Chicago, IL
3Department of Anesthesiology, University of Illinois Chicago – Chicago, IL 4Department of Surgery, University of Illinois Chicago – Chicago, IL
Introduction
•Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis and is the 4th leading cause of cancer-related deaths
•Surgery is one of the main modalities of treatment, but release of circulating tumor cells (CTCs) due to surgical manipulation of the tumor may lead to metastasis
•Src protein tyrosine kinase is expressed significantly in PDAC and its elevated expression is related to tumor aggressiveness
•In vitro studies have shown that the amide local anesthetic lidocaine inhibits Src kinase expression in lung adenocarcinoma cells
•Goal: Examine the effect of lidocaine on Src kinase activity in pancreatic adenocarcinoma cells
Methods
•Used pancreatic cell line PANC1
•Viability testing: cells treated with lidocaine (1µM, 10 µM, 100 µM, 1000 µM, 5000 µM, and 10,000 µM in 1% FBS media) in 48-well plates and incubated (24hr, 37°C)
oCells then stained with Hoechst 33342 (1:1000) and Propidium Iodide (1:1000) to determine percentage of viable cells
•Seeded cells onto 48-well plate, incubated (20min) with or without 20 ng/mL TNF-α (mimics cancer environments)
•Cells treated w/ 10 µM lidocaine or 1% FBS media, incubated (30min)
•Cells immunostained for active phosphorylated (Tyr 418)-Src (pSrc)
•Cells also stained for nuclei with Hoechst 33342 as a standard
•pSrc expression intensity analyzed using ImageJ
•No patient identifiable information, so exempt from IRB review
•Exposure of clinically relevant concentrations of lidocaine for 24 hours yielded no adverse impact on the viability of PANC1 cells
oHigh cell viability was maintained around 95% in 10-100 µM lidocaine
•In subset of PANC1 cells subjected to TNF-α, those treated with 10 µM lidocaine exhibited 60% the level of pSrc as non-lidocaine-treated counterparts (p<0.05)
•In absence of TNF-α, no statistically significant difference in pSrc levels observed between lidocaine-treated PANC1 cells and untreated counterparts
•Quantitative analysis of Src kinase activity in both control and lidocaine-treated PANC1 cells was conducted by assessing the ratio of fluorescence intensity of nuclei to cellular pSrc
Discussion
•Our investigation has established a substantial reduction in cellular pSrc levels in PANC1 cells exposed to TNF-α and subsequent lidocaine treatment
•These findings suggest that lidocaine, administered at therapeutic concentrations, holds the potential to effectively inhibit TNF-α-dependent Src activity
•Previous studies have indicated that Src may also regulate tissue remodeling and degradation of the extracellular matrix in pancreatic cancer cells
•It has been postulated that Src inactivation could suppress cellular invasiveness, including the inhibition of cellular motility and alterations in cell-cell and cell-extracellular matrix interactions
•Our research is extending the scope of this study to pancreatic cancer patients undergoing surgical interventions
oWe are applying our methods to study the effect of lidocaine infusions on pancreatic cancer patients diagnosed with PDAC undergoing surgery
oThese studies will provide valuable insights into the clinical applicability of lidocaine in modulating cancer-related processes and may affect the anesthetic management of cancer patients undergoing surgery
Acknowledgement
These studies are supported by the ASRA Pain Medicine Carl Koller Memorial Research Grant
