Honors Mary Ann, Kinzig Kimberly P
a Department of Psychological Sciences and Ingestive Behavior Research Center , Purdue University , West Lafayette , Indiana , USA.
Nutr Cancer. 2014;66(5):872-8. doi: 10.1080/01635581.2014.916325. Epub 2014 Jun 4.
Obesity and insulin resistance are associated with increased risk of cancer and cancer mortality. However, it is currently unknown whether they contribute to the development of cancer cachexia, a syndrome that contributes significantly to morbidity and mortality in individuals with cancer. The present experiment addresses the question of whether preexisting obesity and insulin resistance alter tumor growth and cancer cachexia symptoms in Yoshida sarcoma bearing male rats. Obesity and insulin resistance were induced through 5 weeks of high-fat (HF) diet feeding and insulin resistance was confirmed by intraperitoneal glucose tolerance testing. Chow-fed animals were used as a control group. Following the establishment of insulin resistance, HF- and chow-fed animals were implanted with fragments of the Yoshida sarcoma or received a sham surgery. Tumor growth rate was greater in HF-fed animals, resulting in larger tumors. In addition, cancer cachexia symptoms developed in HF-fed animals but not chow-fed animals during the 18-day experiment. These results support a stimulatory effect of obesity and insulin resistance on tumor growth and cancer cachexia development in Yoshida sarcoma-bearing rats. Future research should investigate the relationship between obesity, insulin resistance, and cancer cachexia in human subjects.
肥胖和胰岛素抵抗与癌症风险及癌症死亡率增加相关。然而，目前尚不清楚它们是否会导致癌症恶病质的发生，癌症恶病质是一种对癌症患者的发病率和死亡率有显著影响的综合征。本实验探讨了预先存在的肥胖和胰岛素抵抗是否会改变吉田肉瘤雄性大鼠的肿瘤生长和癌症恶病质症状。通过5周的高脂（HF）饮食喂养诱导肥胖和胰岛素抵抗，并通过腹腔葡萄糖耐量试验确认胰岛素抵抗。以普通饲料喂养的动物作为对照组。在建立胰岛素抵抗后，给高脂喂养和普通饲料喂养的动物植入吉田肉瘤组织块或进行假手术。高脂喂养动物的肿瘤生长速度更快，导致肿瘤更大。此外，在为期18天的实验中，高脂喂养动物出现了癌症恶病质症状，而普通饲料喂养动物未出现。这些结果支持肥胖和胰岛素抵抗对携带吉田肉瘤大鼠的肿瘤生长和癌症恶病质发展具有促进作用。未来的研究应调查肥胖、胰岛素抵抗和癌症恶病质在人类受试者中的关系。
