Christopher Heinen, Ph.D.
Investigator,
Center for Molecular Medicine
Assistant Professor of Medicine
Neag Comprehensive Cancer Center Colon Cancer Prevention
Program
Email: cheinen@uchc.edu
Phone: 860-679-8859
Fax: 860-679-7639
Research Interests
Colorectal cancer is the third most common cancer in men
and women and ranks behind only lung cancer in cancer
deaths. My laboratory is interested in studying
the molecular biology of colorectal cancer development.
The most common familial syndrome predisposing patients to
increased colorectal cancer risk is hereditary non-polyposis
colon cancer (HNPCC). HNPCC stems from mutations
in DNA mismatch repair (MMR) genes. Although
many functional details have emerged regarding the MMR
system, the ultimate question of why defects in MMR cause
cancer remains. Faulty MMR results in an
elevated mutation rate (mutator phenotype), which has been
proposed to lead to an accumulation of oncogene and tumor
suppressor mutations that ultimately cause cancer. More
recent work has revealed that MMR proteins play an important
role in cell cycle arrest and apoptosis in response to
certain DNA damaging agents. Thus, MMR mutations may affect
tumorigenesis through multiple mechanisms. Our laboratory is
interested in understanding what functions of the MMR system
are affected during tumorigenesis.
We are currently focusing on two MMR
genes, hMSH2 and hMSH6 . Their
protein products function together as heterodimers to
recognize a DNA lesion and initiate the repair/signaling
process. Mutations of both genes have been
identified in HNPCC patients; a subset of which are missense
mutations. We are utilizing these
cancer-associated missense mutants as tools to understand
which functions of the normal MMR system are affected during
tumorigenesis. Our approach includes an
examination their biochemical and biophysical properties,
their cellular functions including their ability to perform
DNA repair, apoptosis and cell cycle checkpoint signaling,
and finally, their in vivo effects on disease
development and progression utilizing transgenic mouse
models.
We are also interested in understanding whether MMR
defects can be observed in the earliest pre-neoplastic
colorectal lesion termed the aberrant crypt foci.
These grossly identified aberrant crypts may be early
biomarkers for cancer development and we wish to understand
what role loss of MMR function plays in their formation and
progression.
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