Cytochrome P450IIE1 (P450IIE1) is involved in metabolic activation of carcinogenic nitrosamines, aniline and benzene. We detected a restriction fragment length polymorphism of the human P450IIE1 gene with the restriction endonuclease Oral. The population was thus divided into three genotypes, namely, heterozygotes (CD) and two forms of homozygotes (CC and DD). The distribution of these genotypes among lung cancer patients differed front that among controls with statistical significance of P< 0.05 (x2=7.01 with 2 degrees of freedom). This result strongly suggests that host susceptibility to lung cancer is associated with the Dral polymorphism of the P450IIE1 gene.

A bacterium that produced a large amount ofpoly(y-glutamic acid) (PGA) when it was grown aerobically in a culture medium containing ammonium salt and sugar as sources of nitrogen and carbon, respectively, was isolated from soil. The bacterium, strain T AM-4, was classified as Bacillus subti/is. The maximum PGA production (22.1 mg/ml) was obtained when it was grown in a medium containing 1.8% ammonium chloride and 7.5% fructose at 30°C for 96 h with shaking. Some properties of the PG A obtained at different times of cultivation were investigated by gel permeation chromatography, SDS-PAGE, and measurement of viscosity, and calculation of the D/L ratio of glutamic acid constituting PGA. The results suggested that PGA was elongated with no changes in the diastereoisomer ratio in the molecule.

Oral and cutaneous tissues are the most frequent origin in canine squamous cell carcinoma (SSC). In SCC, changes in adhesion molecule expression and transition from epithelial to mesenchymal phenotype are thought to be important in development of invasive behavior of neoplastic cells at the leading front of the tumor. We therefore investigated histological invasive front grading and epithelial-mesenchymal transition (EMT) in both oral SCCs and cutaneous SCCs. EMT was assessed by evaluating immunohistochemical expression of E-cadherin, β-catenin, desmoglein, vimentin, and N-cadherin. Regardless of the anatomic location, invasive front grading resulted in higher histological grades than grading of the surface. Most oral SCCs were of significantly higher histologic grade than cutaneous SCCs ( P < .01). Expression of E-cadherin, β-catenin, and desmoglein was significantly lower in oral SCC compared with cutaneous SCC ( P < .01). A significant association was found between invasive front grading and loss of E-cadherin, β-catenin, and desmoglein ( P < .01). Also, vimentin-positive neoplastic cells had low immunoreactivity of these adhesion molecules, and a few of these neoplastic cells were positive for N-cadherin. These results suggest not only E-cadherin and β-catenin but also desmoglein as markers for predicting biological behavior of canine SCC. Depending on their primary sites, EMT correlates with biological behavior and therefore histological grade of canine SCC. We suggest that combining invasive front grading with assessment of immunohistochemical expression of E-cadherin, β-catenin, and desmoglein may allow more accurate prediction of biological behavior of canine SCCs.

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