Is n-CAM expressed in mature extraocular muscles in a pattern conserved among three species?
Populations of mature myofibers from all six extraocular muscles express N-CAM homogeneously on their cell surfaces. The orbital layer was almost completely N-CAM positive. When the staining pattern of the global layer of the rectus and oblique muscles is compared, not only did the rectus muscles have greater numbers of N-CAM-positive fibers, all rectus muscles showed both extracellular and intracellular N-CAM expression. This was in contrast to the oblique muscles, in which the number of N-CAM-positive fibers was reduced but N-CAM was only present extracellularly. Because of the exclusive involvement of the extraocular muscles in Graves' ophthalmopathy, the absence of N-CAM expression on other mature skeletal muscles, and the increased expression of N-CAM in those muscles (rectus) more affected in this disease, the authors postulate that N-CAM expression may at least be a marker for susceptibility to, if not play a clinically significant role in, the etiology and pathobiology of this disease. Complex patterns of association were demonstrated between N-CAM expression and myosin types, indicating that N-CAM-positive myofibers do not conform to a specific fiber type as traditionally defined.
COX-2 overexpression was significantly correlated with depth of invasion, tumor stage and survival in ESCC. Evaluation of COX-2 expression should be useful for determining tumor properties, including prognosis, in patients with ESCC.