2171

FABP5

fatty acid binding protein 5 (psoriasis-associated);FABP5;fatty acid binding protein 5 (psoriasis-associated)

epidermal-type fatty acid-binding protein|fatty acid-binding protein, epidermal|psoriasis-associated fatty acid-binding protein homolog

8q21.13

protein-coding

AIM: To detect the expression pattern of fatty acid binding protein (FABP) in human breast cancer, and to find potential markers and therapeutic targets for breast cancer. METHODS: adipocyte-FABP (A-FABP), heart or muscle FABP (H-FABP), brain-FABP (B-FABP), epidermis or psoriasis FABP (E-FABP), liver FABP (L-FABP), intestinal FABP (I-FABP) and gastro-FABP (G-FABP) expression in 35 ductal infiltrating carcinoma and 16 fibroadenoma of breast were detected by RT-PCR, immunohistochemical staining and Western blot analysis, respectively. RESULTS: E-, L-, and H-FABP were up regulated significantly in ductal infiltrating carcinoma when compared with those in benign tissue (P<0.05). However, there were not significant difference in A-, B-, G-, and I-FABP expression between ductal infiltrating carcinoma and benign tissue (P>0.05). Interestingly, H-FABP was not only found in benign tissues but in some of ductal infiltrating carcinomas, furthermore, H-FABP level was elevated in malignant tissue, compared with that in benign tissue. CONCLUSION: E-, L-, and H-FABP may play a key role in the progress of invasiveness and metastasis in human breast cancer. Furthermore, the secretion of these FABPs has the potential to serve as a diagnostic marker for breast cancer.

Intrahepatic cholangiocarcinoma (ICC) is a rare primary malignant liver tumor with an extremely poor prognosis. Recently its incidence has increased, however, little attention has been directed to factors related to its molecular carcinogenesis, including oncogenes, tumor suppressor genes and cell cycle-related proteins. ICC is generally characterized by strong proliferation, invasion and early metastasis. These biological behaviors of ICC, with respect to the genetic and molecular aspects, remain to be clarified. In this study, we performed a proteomic analysis to identify the proteomic alterations associated with carcinogenesis of ICC. Protein expression profiles of sixteen cases of ICC were compared with those of adjacent non-involved bile duct tissue. Among the 151 protein spots that showed a statistically significant expression difference (P<0.05), there were 50 spots with significantly increased intensity (3-fold increase) and 17 spots with decreased intensity (3-fold decrease) in cancerous tissues. Of these, increased expression of fatty acid-binding protein 5 (FABP5) was further confirmed by western blot analysis and immunohistochemical analysis. Immunohistochemical analysis of FABP5 expression in tumor specimens obtained from 43 patients with mass-forming (MF) type ICC showed a positive correlation of FABP5 immunoreactivity with tumor size (P=0.047), lymph node metastasis (P=0.013), angioinvasion (P=0.032) and staging (P=0.007). In addition, silencing FABP5 with short hairpin RNA (shRNA) suppressed cell proliferation and invasiveness in HuCCT1 cells, and conversely, overexpression of FABP5 in FABP5-negative Hep3B cells increased cell proliferation and invasiveness. Our study shows that FABP5 is significantly overexpressed in ICC combined lymph node metastasis and is involved in cell proliferation and invasion in vitro. Our data suggest that FABP5 may be associated with tumor progression in ICC.