Identification and characterization of differentially expressed genes in human gastric carcinoma

• Main Authors: Wan Li Cheng, 鄭婉俐
• Other Authors: K. H. Lin
• Format: Others
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/24978225902855827851

博士 === 長庚大學 === 基礎醫學研究所 === 96 === Complementary DNA microarrays have identified aberrantly expressed genes in patients with gastric cancer. One that encodes secretory leukocyte protease inhibitor (SLPI) is among the most exuberantly expressed genes and is associated with metastasis in gastric cancers. The other one encodes GRO1 ONCOGENE (GRO-1) is also associated with metastasis. We evaluated the potential of SLPI and GRO-1 expression as helpful biomarkers for detection of gastric cancer. Tumor tissue and matching noncancerous mucosa were obtained from 60 patients immediately after gastric resection. SLPI and GRO-1 expression levels were determined by Western blot tests and quantitative-reverse transcriptase-polymerase chain reaction (Q-RT-PCR). Paraffin-fixed tumor tissues were used for immunohistochemistry study in 119 patients. A consistent result was obtained between all examinations except plasma SLPI. Both SLPI and GRO-1 mRNA transcripts and protein were overexpressed in gastric cancer cells, and the depth of wall invasion was significantly greater in serosa-invading (T3 and T4) cancers compared to the serosa-free (T1 and T2) cancers. These enhanced expressions were significantly associated with lymph node metastasis, and were significantly higher in stages III and IV, and higher than those in stages I and II. Five-year survival of patients with lower expression of both SLPI and GRO-1 genes were significantly better than among patients with a higher expression. To better understand the function of SLPI and GRO-1 in human gastric cancer cells, isogenic SLPI and GRO-1 overexpressing cell lines (AZ521) were prepared. The migratory and invasive abilities were increased both in SLPI and GRO-1 overexpressing cell lines. The results point to SLPI and GRO-1 as potential prognostic markers for gastric cancer and its function in cell invasion.