油脂化学の立場からみた癌発生原因の一考察

癌組織の脂質 (第3報)

抄録

It may be inferred that if oxidized lipids would form complexes with nucleoproteins of cells, the status of cell division might be probably changed and cancerous cells might be provoked. Then, the cancerous tissue should contain oxidized lipids. Experimental studies were planned according to this this point of view and trans-traps conjugated diene hydroperoxide was ascertained to find it in the lipids of cancerous tissues, such as gastric scirrhous carcinoma, gastric adenocarcinoma, rectal adenocarcinoma, and mammary carcinoma. In case of lung cancer whose generation is different from the generation of those cancers mentioned above in having a possible connection with free radicals contained in cigarette smoke, it may be inferred that the lipids of the tissue may change into oxidized lipids by oxidation catalyzed by the free radicals, oxidized lipids produce free radicals, which in turn produce oxidized lipids, and then the lung cancer may be generated. Then, the tissue of lung cancer should also contain oxidized lipids. Experimental studies revealed that trans-trans or cis-trans conjugated diene hydroperoxide existed in the lipids from the tissue of bronchial carcinoma, a kind of lung cancer, and from cancerous pleural fluids. Taking these studies of the author and other literatures into consideration, the author presented a hypothesis that “cancer is generated owing to oxidized lipids accumulated in a living body” (written as (A) in the following), and he demonstrated the hypothesis (A). The author discussed the reason why Japanese suffer more from gastric cancer and liver cancer than American or English from the difference of food habits and could proved that (A) explain this point. The author discussed the reason why Japanese suffer less from lung cancer than American or English from the difference of living circumstances and decided that (A) could also explain this point. Further the author attributed the inhibition of β-oxidation n cancerous tissue to be explicable, by (A). The author also proved that (A) could explain the decrease in catalase activity in cancer, generation of cancer by radiant rays, and production of cancer by arsenic. Thus the hypothesis (A) may be valuable to afford general understanding of cancer generation.