Anti-DHX9 monoclonal antibody, clone FQS24632

Research has shown that long noncoding RNAs (lncRNAs) play significant roles in colorectal cancer (CRC). However, the role of lnc-UCID (lncRNA upregulating CDK6 by interacting with DHX9) in CRC remains largely unknown. In the present study, analyses revealed that lnc-UCID was markedly upregulated in CRC compared with that in normal specimens. Functional experiments showed that the depletion of lnc-UCID inhibited CRC cell invasion and migration significantly, while overexpression of lnc-UCID had the opposite effect. A candidate target of lnc-UCID, microRNA miR-152-3p, was identified using bioinformatic analysis. Moreover, in CRC tissue, we noted an inverse correlation between miR-152-3p and lnc-UCID expression levels. Overexpression and knockdown experiments revealed opposing roles for miR-152-3p and lnc-UCID, suggesting that lnc-UCID negatively regulates miR-152-3p. Luciferase reporter assays demonstrated that miR-152-3p directly targets lnc-UCID. The results suggest that lnc-UCID acts as an endogenous miRNA sponge, competing for miR-152-3p binding and thereby regulating the miRNA's targets. Overall, we propose that the lnc-UCID/miR-152-3p/Wnt/beta-catenin signaling axis represents a novel mechanism that explains the migration and invasion of CRC.

DHX9/RNA helicase A (RHA) is a host RNA helicase that participates in many critical steps of the HIV-1 life cycle. It co-assembles with the viral RNA genome into the capsid core. Virions deficient in RHA are less infectious as a result of reduced reverse transcription efficiency, demonstrating that the virion-associated RHA promotes reverse transcription before the virion gains access to the new host's RHA. Here, we quantified reverse-transcription intermediates in HIV-1-infected T cells to clarify the mechanism by which RHA enhances HIV-1 reverse transcription efficiency. Consistently, purified recombinant human RHA promoted reverse transcription efficiency under in vitro conditions that mimic the early reverse transcription steps prior to capsid core uncoating. We did not observe RHA-mediated structural remodeling of the tRNA(Lys3)-viral RNA-annealed complex. RHA did not enhance the DNA synthesis rate until incorporation of the first few nucleotides, suggesting that RHA participates primarily in the elongation phase of reverse transcription. Pre-steady-state and steady-state kinetic studies revealed that RHA has little impact on the kinetics of single-nucleotide incorporation. Primer extension assays performed in the presence of trap dsDNA disclosed that RHA enhances the processivity of HIV-1 reverse transcriptase (RT). The biochemical assays used here effectively reflected and explained the low RT activity in HIV-1 virions produced from RHA-depleted cells. Moreover, RT activity in our assays indicated that RHA in HIV-1 virions is required for the efficient catalysis of (-)cDNA synthesis during viral infection before capsid uncoating. Our study identifies RHA as a processivity factor of HIV-1 RT.