1. Presented by: Sarah Ferrer Under the mentorship of Dr. Andrew Buermeyer of the OSU Environmental and Molecular Toxicology Department

2.  MMR deficiency linked to colorectal (and other) cancer predisposition.  Lynch Syndrome causes premature cancer occurrence and greater reoccurrence.

3.  MMR protects against DNA mutations.

4.  PAHs are carcinogens found in the environment.  Metabolized by the liver and colon into diol epoxides.  PAHs used in my research project:  Benzo-[a]-pyrene  Benzo-[c]-phenanthrene  MMR proteins can bind to and recognize PAH adducted DNA

5. MMR proficient cells are more effective at maintaining DNA integrity in human lymphoblastic cell lines than MMR deficient cells when exposed to PAHs benzo-[a]-pyrene and benzo-[c]-phenanthrene.

6.  Human lymphoblastoid cell lines TK6 and MT1  Maintained under the following conditions:  10% complete RPMI media  Incubated with 5% carbon dioxide and at 38°C  Cell density between 5 x 10 4 cells/mL and 1 x 10 6 cells/mL

7.  Growth curves created over several dilutions and compared to the characterized doubling times.

8.  Hypoxanthine guanine phosphoribosyl transferase (HPRT) reporter gene. Culture with 12 million cells Plating efficiency plate 6-TG exposed plate RPMI w/ HAT media Normal RPMI media

9.  Re-run previous experiment to determine MF.  Pick 6-TG resistant colonies and analyze for types of mutations. Normal HPRT + cell Cell with HPRT - DNA, but HPRT + proteins Cell with HPRT - DNA and proteins

10. When exposed to benzo-[a]-pyrene and benzo- [c]-phenanthrene, MMR deficient cells lines exhibit a higher mutant frequency in the HPRT gene than MMR proficient cells.

11.  Dr. Andrew Buermeyer  Vidya Schalk  Kevin Ahern  Howard Hughes Medical Institute