Differential expression of lipid metabolism-related proteins in different breast cancer subtypes.
OBJECTIVE
This study aimed to determine the expression and clinical significance of proteins that are involved in lipid metabolism in human breast tumors.


METHODS
Tumors from 476 breast cancer patients were used to construct tissue microarrays. Then, immunohistochemistry (IHC) for hormone-sensitive lipase (HSL), Perilipin 1 (PLIN1), fatty acid binding protein 4 (FABP4), carnitine palmitoyltransferase IA (CPT-1A), acyl-CoA oxidase 1 (ACOX-1), and fatty acid synthase (FASN) was performed on these microarrays.


RESULTS
Breast tumors were classified into 4 subtypes: luminal A (n = 242; 50.8%), luminal B (n = 134; 28.2%), human epidermal growth factor receptor 2 (HER2) (n = 50; 10.5%), and triple negative breast cancer (TNBC) (n = 50; 10.5%). The expression of PLIN1 (p < 0.001), FABP4 (p = 0.029), CPT-1A (p = 0.001), ACOX-1 (p < 0.001), and FASN (p < 0.001) differed significantly among these tumor subtypes. Notably, PLIN1, CPT-1A, and FASN expression was highest in HER2 tumors and lowest in TNBC tumors. Similarly, the expression of FABP4 and ACOX-1 was highest in HER2 tumors and lowest in luminal A tumors. In addition, ACOX-1 positivity was associated with significantly shorter overall survival (p = 0.018). When tumor subtype was considered, FABP4 positivity was associated with significantly shorter disease-free survival (p = 0.005) and overall survival (p = 0.041) in TNBC.


CONCLUSIONS
Lipid metabolism-related proteins are differentially expressed in different IHC subtypes of breast cancer and some are associated with decreased survival rates.
Department of Pathology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Republic of Korea.
Sewha
S
Kim
Department of Pathology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Republic of Korea.
YuKyung
Y
Lee
Department of Pathology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Republic of Korea.
Ja Seung
JS
Koo
D001943:Breast Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D045744:Cell Line, Tumor; D005260:Female; D015870:Gene Expression; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D053208:Kaplan-Meier Estimate; D050356:Lipid Metabolism / Q000235:genetics*; D008875:Middle Aged; D015999:Multivariate Analysis; D060787:Neoplasm Grading; D016016:Proportional Hazards Models