Circular dumbbell miR‑34a‑3p and ‑5p suppresses pancreatic tumor cell‑induced angiogenesis and activates macrophages

Abstract

Angiogenesis is a tightly regulated biological process by which new blood vessels are formed from pre-existing blood vessels. This process is also critical in diseases such as cancer. Therefore, angiogenesis has been explored as a drug target for cancer therapy. The future of effective anti-angiogenic therapy lies in the intelligent combination of multiple targeting agents with novel modes of delivery to maximize therapeutic effects. Therefore, a novel approach is proposed that utilizes dumbbell RNA (dbRNA) to target pathological angiogenesis by simultaneously targeting multiple molecules and processes that contribute to angiogenesis. In the present study, a plasmid expressing miR-34a-3p and-5p dbRNA (db34a) was constructed using the permuted intron-exon method. A simple protocol to purify dbRNA from bacterial culture with high purity was also developed by modification of the RNASwift method. To test the efficacy of db34a, pancreatic cancer cell lines PANC-1 and MIA PaCa-2 were used. Functional validation of the effect of db34a on angiogenesis was performed on human umbilical vein endothelial cells using a tube formation assay, in which cells transfected with db34a exhibited a significant reduction in tube formation compared with cells transfected with scrambled dbRNA. These results were further validated in vivo using a zebrafish angiogenesis model. In conclusion, the present study demonstrates an approach for blocking angiogenesis using db34a. The data also show that this approach may be used to targeting multiple molecules and pathways.

Different HCV Exposure Drives Specific miRNA Profile in PBMCs of HIV Patients

“…The miR-126-5p hepatic expression has been associated with HCV viral load [ 26 ], the circulating hsa-miR-34a-5p promotes liver fibrosis in CHC [ 27 ], and the hsa-miR-148b-3p has been previously identified as dysregulated in PBMCs of HIV patients [ 28 ]. Although these miRNAs were also associated with the regulation of carcinogenesis and antitumor responses [ 29 , 30 ], we found them involved in the PI3K-Akt signaling pathway. Both HIV and HCV infections promote the activation of the PI3K-Akt signaling pathway, often resulting in other pathogenesis, such as increasing the risk of viral carcinogenesis, and triggering immune-dependent processes, such as inflammation [ 31 , 32 ].…”

“…Both HIV and HCV infections promote the activation of the PI3K-Akt signaling pathway, often resulting in other pathogenesis, such as increasing the risk of viral carcinogenesis, and triggering immune-dependent processes, such as inflammation [ 31 , 32 ]. Therefore, the enhanced expression that we have observed of miR-126-5p, miR-34a-5p and miR-148b-3p in HIV/HCV patients—and their putative target genes HOTAIR , SLC45A3 , UGT8 , VEGFA —could be associated with a higher immune pro-inflammatory responses and deregulation of carcinogenic genes [ 30 , 33 ], which is common in HIV/HCV patients.…”

Noncoding RNA therapeutics — challenges and potential solutions

“…RNAs in circular form are much more stable than their linear counterparts. Multiple circular small RNAs have been synthesized, including dumbbell shaped (dbRNA) 172 – 174 , covalently closed 175 , 176 and linker-circularized 177 , 178 siRNAs. Interestingly, many of these circularized siRNAs were not only more stable but also mediated more efficient and prolonged RNAi effects 172 , 173 , 176 .…”

“…dbRNA, for example, mediated stronger and longer RNAi effects at lower concentrations 173 . A miR-34a-3p- and miR-34a-5p-containing dbRNA (db34a) inhibited angiogenesis in an in vitro model as well as in a zebrafish model 174 . Covalent closure of only the passenger strand to prevent its RISC loading could significantly reduce off-target effects in vitro 175 .…”

“…Covalent closure of only the passenger strand to prevent its RISC loading could significantly reduce off-target effects in vitro 175 . In fact, circularization seems to overcome multiple hurdles experienced by linear siRNAs, showing less immune stimulation 176 , 178 , higher stability and bioavailability 172 , 174 , 175 , 177 , high efficacy 172 , 173 , 176 and increased cellular uptake 176 .…”