Cancer, metastasis and the entire business of vesicle trafficking

Vesicle trafficking plays a part in cellular processes. Vesicles are formed, undergo expansion and completion, and finally participating in lysosomal degradation. Vesicles are involved in this process known as autophagy. Autophagosomes are double-membrane vesicles. In a paper published by Takahashi et al in Nature Cell Biology, it was found that Bif-1 interacts with Beclin-1, and together with ATG-5, is involved in the formation of autophagosomes. Loss of Bif-1 led to abrogation of autophagy, and the arising of spontaneous tumours in mice (Takahashi et al, 2007). It was also found that during the process of carcinogenesis in mice, there was reduced autophagic activity (Schwarze and Seglen, 1985). Indeed, it's interesting to note the part played by vesicle trafficking pathways in tumorigenesis. Vesicle trafficking pathways may play a part in metastasis. Jiang et al has found that the regulation of matrix metalloproteinase-1 activity was achieved by dynamin-mediated endocytosis (Jiang et al, 2001). The study of vesicle trafficking pathways in cancer and metastatic cells will gives us insights into how they actually assist in the latter's functions.


Citations

1) Yoshinori Takahashi, Domenico Coppola, Norimasa Matsushita, Hernani D. Cualing, Mei Sun, Yuya Sato, Chengyu Liang, Jae U. Jung, Jin Q. Cheng, James J. Mul, W. Jack Pledger & Hong-Gang Wang. Bif-1 interacts with Beclin 1 through UVRAG and regulates autophagy and tumorigenesis. Nature Cell Biology, 23 Septemter 2007

2) Schwarze, P. E. & Seglen, P. O. Reduced autophagic activity, improved protein balance and enhanced in vitro survival of hepatocytes isolated from carcinogen-treated rats. Exp. Cell Res. 157, 15–28 (1985)

3) Jiang A, Lehti K, Wang X, Weiss SJ, Keski-Oja J, Pei D. Regulation of membrane-type matrix metalloproteinase 1 activity by dynamin-mediated endocytosis. Proc Natl Acad Sci U S A. 2001 Nov 20;98(24):13693-8.