脂肪在恶性肿瘤治疗中的作用

Role of lipids to tumorbearing hosts

恶性肿瘤患者常伴有不同程度的营养不良,在接受各种治疗的同时需进行营养支持.然而,营养支持的顾虑在于各种营养措施同时对肿瘤生长的刺激作用.提供外源性脂肪,即应用脂肪乳剂似可无此顾虑,因为恶性肿瘤组织不能如正常机体组织那样氧化脂肪而提供能量;甘油三酯中的长链多不饱和脂肪酸(PUFA)可通过改变恶性肿瘤细胞的膜流动性使之对其它治疗敏感.另外也有可能甘油三酯通过对自由基和脂质过氧化的增强作用直接杀伤肿瘤细胞.ω-3长链多不饱和脂肪酸还可通过调节前列腺素产量来调节免疫过程抑制肿瘤或者直接抑制肿瘤增殖.但外源性脂肪与恶性肿瘤及其宿主相互作用的肯定结论有待进一步研究.

The use of nutrition support in the tumor bearing host may improve the host's nutritional status as well as stimulate primary tumor growth. Exogenous lipids may not stimulate the tumor growth because they can not be used by the tumor tissues. PUFA(Ployunsaturated fatty acids)in lipids make tumor cells sensitive to treatments by modulating the membrane fluidity. PUFA may also kill the tumor cells directly by augmenting the production of free radicales and lipid peroxidation. ω-3 PUFA are more effective than ω-6 PUFA in that the former may in the meantime inhibit the production of PGE_(2), which may inhibit immune response and promote tumor growth. Further studies are needed on the role of lipids to tumor-bearing hosts.