Abstract: Objective To investigate the expression of fragile histid ine triad (FHIT)gene and its relationship with the proliferation and apoptosis of tumor cells in cutaneous malignant melanoma (CMM). Methods The expression of FHIT gene and PCNA were detected by streptavidin peroxidase method with skin specimens taken from 57 primary cutaneous melanoma and 20 normal controls.Apoptosis of tumor cells was detected by terminal deoxynuclneotidyl transferase mediated dUTP nick end labeling (TUNEL). Results The expression level of FHIT protei n was significantly lower in CMM than that in the normal skin tissue (P<0.001),on the contrary,the level of PCNA and apoptosis index were significantly higher in CMM than those in the normal skin tissue (P<0.001).The expression level of FHIT protein,PCNA and apoptosis index were not related to patients' age,sex and distribution of melanoma,but closely related to Clark level and lymphnode involvement of CMM.AI/PCNA ratio was significantly lower in CMM than that in the normal controls(P<0.01).The reduced expression of FHIT protein might berelated to over-proliferation and suppression of apoptosis of CMM cells (P<0.01). Conclusions FHIT gene may play a role in the regulation of proliferation and apoptosis of tumor cells in CMM.The reduced expression of FHIT protein may be related to the pathogenesis and development of CMM.

Key words: FHIT gene, Melanoma, Proliferating cell nuclear antigen, Apoptosis