RESUMO
Peutz-Jeghers syndrome (PJS) is a rare autosomal dominant inherited disorder characterised by gastrointestinal (GI) hamartomatous polyposis and mucocutaneous pigmentations. PJS is associated with an increased cancer risk, including GI and various extra-GI malignancies. In this study, we tracked this family for 8 years, and analyzed the clinical data of the PJS pedigree including two generations. In our research, the studied family members, including the proband, older daughter and younger daughter, all detected to have three heterozygous mutations in the RET gene that were inherited from the proband. The existed three mutant spots included exon 5 (GTG>ATG, Val292Met), exon 2 (CGC>CAC, Arg67His) and exon 18 (CGC>TGC, Arg982Cys) in RET. Our study provides an observation of the genetic heterogeneity of PJS. This pedigree investigation showed that it is critical to establish a long-term follow-up system for PJS patients and their families.
RESUMO
Colorectal carcinoma (CRC) is often lethal when invasion and/or metastasis occur. NAD(+)-dependent 15-hydroxyprostaglandin dehydrogenase (15-PGDH), an enzyme involved in prostaglandin (including PGE(2)) bio-inactivation, is down-expressed in several epithelial malignancies including CRC. Although its role in the suppression of colon tumorigenesis has been well learned, little is known about the role of 15-PGDH in the process of tumor metastasis. Here, we tested the hypothesis that 15-PGDH over-expression in CRC cells results in decreased cell motility and invasion. In this study, 15-PGDH was re-expressed in SW480 cells by the use of gene transient transfection with eukaryotic expression vector pcDNA3.1-PGDH. We confirmed the over-expression of 15-PGDH protein by Western blot and enzymatic activity assay. The cell motility was tested by counting the number of cells crossing an 8-micron pore size PET membrane and by measuring cells migration distance through wound healing assay. Furthermore, cell invasive activity was evaluated by counting the number of cells invading through a Matrigel-coated membrane simulating basement membrane. The effects of 15-PGDH on the adhesion were investigated by MTT assay. Ectopic expression of 15-PGDH in SW480 cancer cells significantly inhibited the cell migratory and invasive capacity in vitro by approximately 1.9- and 8.4-fold, respectively. To test the hypothesis that 15-PGDH affects proteases and inactivates extracellular matrix (ECM), Western blot and gelatin zymography were performed by using serum-free conditioned medium. The results showed that re-expression of 15-PGDH suppresed matrix metalloproteinase-2 (MMP2) synthesis and secretion. In addition, the analysis of the MMP2 activity indicated that re-expression of 15-PGDH could inhibit activation of MMP2. Furthermore, we found that 15-PGDH inhibited cell adhesion to ECM and reduced CD44 expression in SW480 cell. Taken together, these results suggest that induced 15-PGDH expression may contribute to the inhibition of the invasive and metastatic capacity of colon cancer cells in vitro.