Possible role of accessibility of protein-SH groups to the cancer state.

From out histochemical studies, protein-sulfhydryl (SH) groups are found mainly concentrated in the nucleus and in cell nuclear membranes. Both clinically and in sensitivity tests, selected SH inhibitors have been found to be more active than other commonly used anticancer agents, against an array of cancers, than against normal tissues. The same SH inhibitors can induce immunity against some cancers in animals, while causing blunting of microvilli and alterations in cell surface of the cancer cells. From recent electron spin resonance data (ESR), selected SH inhibitors and glyoxal derivatives can raise the low ESR signal of cancers towards or above normal. The variety of important roles of protein-SH groups to the cancerous state underscores the possible role of accessibility of protein-SH groups to cancer. This very importance of protein-SH groups to cancer, with their highly variable chemical reactivity, underscores also the lack of validity of randomized protocols for clinical cancer therapy. None of these take into account any measure of the chemical sensitivity of each patient's own cancer.