B149
Gemcitabine resistance in pancreatic cancer cell lines correlates with the expression of key proteins its uptake and metabolism
Khaled Dajani, Sarah Tonack, Bill Greenhalf, Eithne Costello, John P Neoptolemos, Paula Ghaneh
University of Liverpool, UK
Background
Pancreatic cancer cell-lines acquire resistance to gemcitabine when cultured with the drug. The molecular changes responsible for this are unclear.
Aim
To examine the expression profile of proteins involved in gemcitabine uptake and metabolism in gemcitabine sensitive and resistant pancreatic cancer cell lines.
Method
Eight characterised pancreatic cancer cell-lines were cultured in increasing concentrations of gemcitabine to generate resistant cell lines. The mRNA levels for human Equillibrative Nucleoside Transporter1 (hENT1), Cytidine Deaminase (CDA), Deoxycytidylate Deaminase (DCTD) and deoxy-Cytidine Kinase (dCK) were quantified by qRT-PCR, for the parental cell lines, and standardised to 18S. The expression level was presented relative to PANC-1 levels. An MTT assay was used to measure the Ic50 of gemcitabine.
Results
The Ic50 range was 4.5nM to >500 nM. hENT1 mRNA levels in PANC-1 cells were significantly higher than other cell lines (p=0.0007), DCTD mRNA levels were highest in CAPAN-2 (P=0.02). CDA mRNA levels were highest in CAPAN-2 and MIAPaca-2 cells (p=0.003), dCK mRNA levels were highest in CFPAC-1 (p=0.02).
Preliminary data showed a positive association of hENT1 mRNA level and gemcitabine Ic50, this did not reach significance (Coeff=0.74, p=0.09). Negative associations were observed for DCTD and CDA mRNA levels with the Ic50 values (Coeff= -0.47, -0.42 respectively), these were not significant.
Conclusion
Significant differences were demonstrated in mRNA levels of these proteins between pancreatic cancer cell lines and may play a role in gemcitabine chemo-resistance. Validation of these findings, alongside quantification of the mRNA levels in cell lines resistant to gemcitabine and subsequently correlating these with Ic50 levels is ongoing.
