Evaluation of fatty acid synthase expression in oesophageal mucosa of patients with oesophagitis, Barrett's oesophagus and adenocarcinoma

Variation in Fatty Acid Synthase, Ki67 and p53 Esophageal Mucosa Expressions in Barrett's Esophagus Patients Treated for One Year with Two Esomeprazole Different Regimens

Barrett's esophagus (BE) is an acquired pre-malignant condition that results from chronic gastroesophageal reflux. The malignant transformation occurred in 0.5% of patients/year and was independent of medical and endoscopic conservative treatments. Fatty acid synthase (FAS) is a multifunctional enzyme that catalyzes the synthesis of long-chain fatty acids from acetyl-coenzyme A, malonyl-coenzyme A, a reduced form of nicotinamide adenine dinucleotide phosphate (NADPH), and adenosine triphosphate. Activation of FAS is closely linked to malignant transformation. The aim of the present study was to evaluate the variation of FAS, p53, and Ki67 expressions in two groups of 21 BE patients each, after one year of continuous (group A) or discontinuous (group B) treatment with esomeprazole 40 mg/day in comparison to the initial expression. In both the two groups of BE patients, biopsies were taken from pathologic sites of the mucosa for histological and immuno-histochemical detection of FAS, Ki67, and p53 at entry and after one year of Esomeprazole 40 mg treatment. FAS expression was positive when a strong granular cytoplasmic staining was observed in esophageal cells. Ki67 and p53 were defined as positive when nuclear staining was clearly detected at ×10 magnification. FAS expression was reduced in 43% of patients treated with Esomeprazole continuously in comparison to the 10% of patients treated with Esomeprazole on demand (p = 0.002). Ki67 expression was reduced in 28% of continuously treated patients in comparison to 5% of patients treated on demand (p = 0.001). The p53 expression decreased in 19% of continuously treated patients in comparison to an increase in 2 patients (9%) treated on demand (p = 0.05). Continuously Esomeprazole treatment could help in the diminution of metabolic and proliferative activities in the esophageal columnar epithelium and in part it can help prevent the oxidative damage against cellular DNA, resulting in a diminution in p53 expression.

Fatty acid synthase expression in osteosarcoma and its correlation with pulmonary metastasis

Previous experimental evidence has suggested that fatty acid synthase (FASN) may be involved in cancer metastasis. However, its role has been poorly evaluated in osteosarcoma. The aim of this study was to investigate the correlation of FASN expression with pulmonary metastasis and the correlation of FASN expression with the Ki-67 antigen, a proliferation marker, in patients with osteosarcoma of the extremities. The expression of FASN protein and Ki-67 was detected by immunohistochemistry of biopsy tissues from 136 patients with osteosarcoma of the extremities and 21 cases of osteoenchondroma. Positive expression of the FASN protein was observed and located in the cytoplasm. The positive expression rate of FASN was 63.2% in osteosarcoma and 28.6% in osteoenchondroma (p<0.05). The expression levels of the FASN protein were higher in the cases with lung metastasis compared to those without metastasis (p<0.01). The percentage of Ki-67 stained nuclei in osteosarcoma with pulmonary metastasis and in those without was 43.43±10.05 and 25.41±6.68%, respectively (p<0.01). There was a positive correlation between FASN and Ki-67 protein expression in osteosarcoma (Spearman's rho, F=43.05, R=0.734). Therefore, FASN may be a promising target in the treatment of osteosarcoma metastasis.