Reduction in squamous cell carcinomas in mouse skin by dietary zinc supplementation

Inadequate dietary Zn consumption increases susceptibility to esophageal and other cancers in humans and model organisms. Since Zn supplementation can prevent cancers in rodent squamous cell carcinoma (SCC) models, we were interested in determining if it could have a preventive effect in a rodent skin cancer model, as a preclinical basis for considering a role for Zn in prevention of human nonmelanoma skin cancers, the most frequent cancers in humans. We used the 7,12-dimethyl benzanthracene carcinogen/phorbol myristate acetate tumor promoter treatment method to induce skin tumors in Zn-sufficient wild-type and Fhit (human or mouse protein) knockout mice. Fhit protein expression is lost in >50% of human cancers, including skin SCCs, and Fhit-deficient mice show increased sensitivity to carcinogen induction of tumors. We hypothesized that: (1) the skin cancer burdens would be reduced by Zn supplementation; (2) Fhit(-/-) (Fhit, murine fragile histidine triad gene) mice would show increased susceptibility to skin tumor induction versus wild-type mice. 30 weeks after initiating treatment, the tumor burden was increased ~2-fold in Fhit(-/-) versus wild-type mice (16.2 versus 7.6 tumors, P < 0.001); Zn supplementation significantly reduced tumor burdens in Fhit(-/-) mice (males and females combined, 16.2 unsupplemented versus 10.3 supplemented, P = 0.001). Most importantly, the SCC burden was reduced after Zn supplementation in both strains and genders of mice, most significantly in the wild-type males (P = 0.035). Although the mechanism(s) of action of Zn supplementation in skin tumor prevention is not known in detail, the Zn-supplemented tumors showed evidence of reduced DNA damage and some cohorts showed reduced inflammation scores. The results suggest that mild Zn supplementation should be tested for prevention of skin cancer in high-risk human cohorts.

Fragile histidine triad (FHIT) gene and its association with p53 protein expression in the progression of gall bladder cancer

OBJECTIVE

Present study deals with LOH and MSI in FHIT gene and p53 expression in GBC, CC, XGC, and normal GB to elucidate the role of FHIT gene in gall bladder cancer.

METHODS

Five microsatellite markers D3S1217, D3S1300, D3S1313, D3S1600, and D3S2757, were selected.

RESULTS

Among GBC cases the frequency of MSI-H and LOH was 17.5% and 27.5%, respectively. Significant difference was found between GBC and normal GB (p = .02), and GBC and CC groups (p= .002) when LOH was compared.

CONCLUSIONS

Our results suggested CC might act as a preinvasive stage in the pathogenesis of GBC.