BUFFALO, NYCancer encompasses more than 100 different diseases
and is caused by a series of molecular changes affecting cellular
function. We will find the solution to cancer at the molecular
level. There are common patterns in tumor formation and certain keys
that are associated with those patterns, said Carlo Croce, MD,
director of the Kimmel Cancer Center, and professor of microbiology
and immunology, Thomas Jefferson University, Philadelphia.
One of those keys may be the FHIT gene, which is often inactivated in
epithelial tumors, he said at the New Horizons in Cancer Prevention
Symposium, hosted by Roswell Park Cancer Institute.
FHIT is most often inactivated in tumors resulting from exposure to a
carcinogen, which modifies the way the gene functions. Research
suggests that this change in FHIT occurs early in the cancer process.
Since the alteration in the FHIT gene occurs early, this gives
us a molecular target to study and possibly change in order to stop
the development of malignant cells, Dr. Croce said.
In a study of preinvasive bronchial dysplasias, various levels of the
loss of FHIT expression were noted. In carcinoma in situ, loss of
FHIT expression was seen in 100% of tumor cells; in dysplasia, 85%;
and in any lesion, 95%.
Even if we cant completely stop the development of lung
cancer, the identification of the loss of FHIT in bronchial tumors
and the potential for a therapy to correct this loss offer an
opportunity to eliminate 80% to 90% of precancerous cells. If this
continues as we hope, we can make a huge impact on lung tumor
incidence, Dr. Croce said.
In initial studies of methods to replace FHIT function in tumor cells
not expressing FHIT, researchers found that restoring the ability to
express FHIT normally caused cancer cells to undergo apoptosis.
This first-look study at replacing the gene offers real hope
for a potential therapy. Additional studies will focus on advancing
this research into lung cancer and identifying other cancers that may
also lose FHIT function before becoming aggressive, Dr. Croce