Rabbit Anti-Human USE1 (a.a. 1-231) Polyclonal antibody

USE1 has been demonstrated to play crucial roles in the development and progression of human lung cancer. However, the antitumor efficacy of RNA interference (RNAi) targeting of USE1 has not yet been evaluated as a possible clinical application. We here synthesized USE1 targeting bubbled RNA-based cargo (BRC) composed of densely packed multimeric pre-siRNAs with specific Dicer cleavage sites to enable efficient siRNA release upon entry to target cells. The physical entanglement and continuous networking of RNAs via hybridization during enzymatic replication serve as a driving force for the self-assembly of BRCs. These molecules effectively suppressed the transcription of their target genes, leading to tumor growth suppression in vitro and in vivo. Moreover, their repeated intravenous administration efficiently inhibited the growth of A549 tumor xenografts. Based on these findings of a reduced cancer cell viability following a USE1 knockdown, we further explored cell cycle arrest and apoptosis pathways. The observed tumor cell growth suppression was found to be controlled by cell cycle arrest and apoptosis signals induced by the USE1 reduction. These results suggest that USE1 BRCs may have future clinical applications as an RNAi-based cancer therapy.

We applied fluorescence microscopy-based quantitative assays to living cells to identify regulators of endoplasmic reticulum (ER)-to-Golgi trafficking and/or Golgi complex maintenance. We first validated an automated procedure to identify factors which influence Golgi-to-ER relocalization of GalT-CFP (beta 1,4-galactosyltransferase I-cyan fluorescent protein) after brefeldin A (BFA) addition and/or wash-out. We then tested 14 proteins that localize to the ER and/or Golgi complex when overexpressed for a role in ER-to-Golgi trafficking. Nine of them interfered with the rate of BFA-induced redistribution of GalT-CFP from the Golgi complex to the ER, six of them interfered with GalT-CFP redistribution from the ER to a juxtanuclear region (i.e. the Golgi complex) after BFA wash-out and six of them were positive effectors in both assays. Notably, our live-cell approach captures regulator function in ER-to-Golgi trafficking, which was missed in previous fixed cell assays, as well as assigns putative roles for other less characterized proteins. Moreover, we show that our assays can be extended to RNAi and chemical screens.