Anti-CBX5 monoclonal antibody, clone 4H3-I21-B7 Knockout Validated

Gastric cancer is one of the most frequently diagnosed cancer types in China and also the leading causes of cancer-related death. Previous study showed chromobox 5 expression was elevated in gastric cancer, but little is known regarding the precise molecular mechanisms by which chromobox 5 expression was modulated. In this study, we revealed that chromobox 5 could promote gastric cancer cell proliferation, migration, and invasion in vitro. We screened and identified microRNA-758-3p, whose expression was downregulated in gastric cancer tissues and cell lines, which was a potential upstream molecule of chromobox 5. Upregulation of microRNA-758-3p could markedly downregulate the expression of chromobox 5. Additionally, expression of microRNA-758-3p and chromobox 5 was inversely correlated in gastric cancer tissues. Moreover, microRNA-758-3p overexpression suppressed gastric cancer cell proliferation, migration, and invasion, but these effects can be partially reversed by chromobox 5 overexpression. Collectively, our results indicate that microRNA-758-3p serves as a tumor suppressor and plays a crucial role in inhibiting the proliferation, migration, and invasion of gastric cancer via targeting chromobox 5 and implicate its potential application in cancer therapy.

Heterochromatin protein 1 (HP1) has first been described in Drosophila as an essential component of constitutive heterochromatin required for stable epigenetic gene silencing. Less is known about the three mammalian HP1 isotypes CBX1, CBX3 and CBX5. Here, we applied a tandem affinity purification approach coupled with tandem mass spectrometry methodologies in order to identify interacting partners of the mammalian HP1 isotypes. Our analysis identified with high confidence about 30-40 proteins co-eluted with CBX1 and CBX3, and around 10 with CBX5 including a number of novel HP1-binding partners. Our data also suggest that HP1 family members are mainly associated with a single partner or within small protein complexes composed of limited numbers of components. Finally, we showed that slight binding preferences might exist between HP1 family members. (C) 2011 Elsevier Inc. All rights reserved.