Abstract 5421: Differential expression of lysosomal acid lipase (LAL) between benign and malignant tissues among human organs

Background: Lysosomal acid lipase (LAL), a lysosomal enzyme is able to degrade cholesteryl esters to free fatty acids and cholesterol. The information on the association of LAL with malignancies is limited. This study is to determine the difference in expression level of LAL between benign and malignant tissues among human organs. Method: Immunohistochemistry (IHC) for human LAL was performed on A tissue microarray (TMA) containing 360 benign and malignant tissues from 36 human organs. The expression level of LAL was represented by an IHC score calculated by multiplying area score (0-3) with intensity score (0-3), ranged from 0 to 9. Student’s t-test was used to compare the mean IHC score between benign and malignant tissues in same organs. Results: Eighteen out of 36 human organs have IHC stains on both benign and malignant tissues. As shown in Table 1, LAL expression level was higher in malignancy than in benign tissues in 9 organs. The difference in LAL expression level was significantly (or nearly lower in malignant tissues of adrenal gland, stomach, liver, testis and kidney. Conclusion: The expression level of LAL varies among human organs. As compared with elevation of LAL expression level, decreased expression level of LAL in malignancies could be of more significance. Citation Format: Mohamed EI Gassim, Jinghe Mao, Tangen Ma, Xinchun Zhou. Differential expression of lysosomal acid lipase (LAL) between benign and malignant tissues among human organs [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5421. doi:10.1158/1538-7445.AM2017-5421