The coincidence of a chromosomal fragile site, FRA3B, at a common chromosomal breakpoint in lung cancer has suggested that fragility at this site may predispose to breakage that could contribute to multistep carcinogenesis.
In this report, we describe an improved extruded DOTAP:cholesterol (DOTAP:Chol) cationic liposome that efficiently delivers therapeutic tumor suppressor genes p53 and FHIT, which are frequently altered in lung cancer, to localized human primary lung cancers and to experimental disseminated metastases.
All of these findings are consistent with loss of Fhit protein expression being as frequent an abnormality in lung cancer pathogenesis as are p53 and p16 protein abnormalities and that such loss occurs independently of the commitment to the metastatic state and of most other molecular abnormalities.
We analyzed FHIT gene aberrations in 64 lung cancer tissues and found that the appearance of the aberrant FHIT transcripts depends on the condition of RT-PCR and high telomerase activity, shortened telomere length, and advanced pathological stage were likely associated with the prevalence of aberrant FHIT transcripts, but not with allelic loss of the FHIT gene.
Normal FHIT transcripts in renal cell cancer- and lung cancer-derived cell lines, including a cell line with a homozygous deletion in the FRA3B region.
Our findings support the conclusion that FHIT/FRA3B abnormalities are associated with lung cancer pathogenesis but that FHIT abnormalities differ from the types of mutations and lack of wild-type transcript found in classic tumor suppressor genes, and functional studies are needed to define the role of FHIT in thoracic tumorigenesis.
To avoid overlooking tumor-specific altered transcripts due to contaminating normal cells in primary tumors, FHIT alterations were examined in 41 lung cancer cell lines in the present study.