1. VCU/HHMI Summer Scholars program
IS PLATINUM-BASED DRUG CYTOTOXICITY ENHANCED BY THE ANTIDEPRESSANT DESIPRAMINE?
Sandeep Sharma
VCU/HHMI Summer Scholars program
Mentor: Dr J.J. Ryan
Department of Biology

2. Hypothesis
Since resistance to chemotherapeutic drugs is frequently associated with reduced drug uptake, increasing drug uptake can enhance cell killing. Some anti-depressants can alter the function of transport proteins that allow cells to accumulate drugs. We postulated that the anti-depressant desipramine could enhance cell killing by platinum-based chemotherapy.

3. The two major experiments carried out were:
The Effect of Desipramine on cisplatin (c DDP)-mediated killing of A2780 ovarian carcinoma cells.
Effect of Desipramine on Oxaliplatin + 5FU- Mediated killing of HCT116 colorectal carcinoma cells.

4. Cis-diamminedichloroplatinum(II) c DDP
Background
Cis-diamminedichloroplatinum(II) c DDP
A platinum based chemotherapy drug used to treat several types of cancer such as sarcomas, lyphomas and ovarian cancer.
It was the first member of its class which also includes carboplatin and oxaliplatin.
The cytoxoxicity is mainly through the interactions with DNA and the inhibtion of synthesis and replication by formation of interstrand and intrastrand cross links.

5. Oxaliplatin
Is a platinum based chemotherapy drug. Typically is administered with fluorouracil and leucovorin for the treatment of colorectal cancer.
It has a similar structure to cisplatin where the two amine groups are replaced by cyclohexyl diamine and the chlorine ligands are replaced by the oxalato-bidentate.

6. Fluorouracil 5-FU
Belongs to the family of drugs called antimetabolites. It acts prinicipally as a thymidylate synthase inhibitor, interrupting an enzyme that is critical factor in the synthesis of pyrimidine which is important in DNA replication.

7. Desipramine
Desipramine- A tricyclic antidepressant. Its activity rises from inhibiting reuptake and in the process raising the level of seretonin and norepinephrin in the synaptic cleft.
It is also used for treating neuropathic pain especially with prostate cancer patients.
Desipramine can block organic ion transporters (OCTs), and hence may alter drug uptake.

8. PROTOCOL Tryposonized and collected HCT 116 cells and A2780 cells.
Aliqouted 150,00 cells into 3mL cRPMI(media) in 6 well plates.
Added the different drugs according to the different culture conditions.
Cultured the cells for 72 hours.
Collected adherent and non-adherent cells.
Fixed the cells in ethanol.
Performed PI-DNA staining.
Analysed the cells for DNA content on a FACScan/FACSCalibur flow cytometer.

9. PI DNA STAINING ASSAY Treatment with Drug Fixed overnight Cells
Stained with propidium iodide
Analyzed by Flow Cytometry
Cell Cycle

10. Desipramine Augments c DDP Induced Killing

11. Cell Killing with Desipramine is Better than Oxaliplatin and 5FU Alone

12. Conclusions
Desipramine augments killing of both ovarian and colorectal carcinoma cells.
Other studies from our lab recently showed that desipramine has little or no effect on drug uptake, but enhances the activation of apoptotic pathways, including p53.
Because desipramine is approved for clinical use, it may be an excellent means to augment standard chemotherapeutic treatment.

13. Acknowledgements Dr. Ryan for his tremendous support and guidance.
All members of the Ryan lab for all their help and encouragement:
Peyman Kabolizadeh
Brian Barnstein
Sarah Kennedy
Jenifer Brenzovich
Kevin Dholaria
Dr. Buck and Dr. Johnson.