Environmental wavelengths of ultraviolet light induce cytoskeletal damage.

The ultraviolet component of sunlight is the major cause of skin cancer and is responsible for accelerating the aging of human skin. It is therefore important to determine the mechanisms by which ultraviolet light alters normal cellular functions. The potential importance of ultraviolet light-induced damage to non-DNA targets has received little attention. Since the cytoskeleton is an important participant in the control of normal cell growth, the microfilaments and microtubules of UV irradiated human skin fibroblasts have been studied using fluorescence microscopy. Polychromatic ultraviolet light, composed of environmentally relevant wavelengths, was found to disrupt the cytoplasmic microtubule complex in a dose dependent manner. The induction of microtubule disassembly did not correlate with the cytotoxicity of ultraviolet light of varying composition.