Caveolin-1 expression in HSC-3 cell myoma monocultures. A. Western blotting: caveolin-1 is detected as complex forms in intact myoma (IM) tissue disc extracts (without added cells), and, to a lesser degree, in the rinsed myoma (RM, without added cells and without soluble factors) disc extracts. Monomeric caveolin-1 is absent from both IM and RM tissue extracts. B. HSC-3 monocultures within rinsed myoma (RM) in both normoxic and hypoxic conditions (a, b) show delicate, spindle, caveolin-1-positive cells closely surrounding invading HSC-3 islands. Alpha-smooth muscle actin immunostaining in normoxic and hypoxic conditions (c, d) shows findings similar to caveolin-1 in terms of cell distribution and morphology. HSC-3 monocultures within intact myoma (IM) immunostained with caveolin-1 (e, f) and alpha-smooth muscle (g, h) show findings similar to those of the RM, respectively. CAV1 and alpha-smooth muscle actin positively stain the spindle cells surrounding the invading HSC-3 tumor islands (indicated by arrows). In all sections, the HSC-3 cells are only occasionally CAV1-positive in both RM and IM, and in both normoxia and hypoxia. However, the spindle cells are usually CAV1-positive, showing a high staining intensity.