From selective sensitization or protection to differential action

Cancer cell biology in relevance to cancer therapy was reviewed, especially on its growth, invasion and metastasis. Almost all therapeutic modalities modulate the gene expression of factors involved in the above phenomena, resulting in the promotion of malignant progression. Since local control is needed to avoid the promotion, more selective sensitization of tumor or protection of normal tissue might be required. I propose the possibility of differential action of chemicals on cancer and on normal tissue. Adrenochrome monoaminoguanidine methanesulfonate (AMM) and cytochrome C (CCC) protected peripheral blood leucocytes, especially potent natural killer cells, in patients with lung cancer against radiotherapy. They sensitized human lung cancer xenografts to radiotherapy, probably due to the augumentation of NK activity in the host mice. (author)