Ribonucleic acid interference induced gene knockdown

Antiviral therapeutics for chikungunya virus

Introduction: Chikungunya virus (CHIKV), a reemerging human arthropod borne virus, can causes global epidemic outbreaks and has become a serious health concern due to the unavailability of any antiviral therapy/vaccine. Extensive research has been conducted to target different proteins from CHIKV to curtail the spread of virus.Areas covered: This review provides an overview of the granted patents including the current status of antiviral strategies targeting CHIKV.Expert opinion: Under the current scenario, potential molecules and different approaches have been utilized to suppress CHIKV infection. MV-CHIKV and VRC-CHKVLP059-00-VP vaccine candidates have successfully completed phase I clinical trials and ribavirin (inhibitor) has shown significant inhibition of CHIKV replication and could be the most promising candidates. The drug resistance and toxicity can be modulated by using the inhibitors/drugs in combination. Moreover, nanoparticle formulations can improve the efficacy and bioavailability of drugs.

Delayed Newcastle disease virus replication using RNA interference to target the nucleoprotein

Each year millions of chickens die from Newcastle disease virus (NDV) worldwide leading to severe economic and food losses. Current vaccination campaigns have limitations especially in developing countries, due to elevated costs, need of trained personnel for effective vaccine administration, and functional cold chain network to maintain vaccine viability. These problems have led to heightened interest in producing new antiviral strategies, such as RNA interference (RNAi). RNAi methodology is capable of substantially decreasing viral replication at a cellular level, both in vitro and in vivo. In this study, we utilize microRNA (miRNA)-expressing constructs (a type of RNA interference) in an attempt to target and knockdown five NDV structural RNAs for nucleoprotein (NP), phosphoprotein (P), matrix (M), fusion (F), and large (L) protein genes. Immortalized chicken embryo fibroblast cells (DF-1) that transiently expressed miRNA targeting NP mRNA, showed increased resistance to NDV-induced cytopathic effects, as determined by cell count, relative to the same cells expressing miRNA against alternative NDV proteins. Upon infection with NDV, DF-1 cells constitutively expressing the NP miRNA construct had improved cell survival up to 48 h post infection (h.p.i) and decreased viral yield up to 24 h.p.i. These results suggest that overexpression of the NP miRNA in cells and perhaps live animal may provide resistance to NDV.

Effects of tetraspanin CD151 inhibition on A549 human lung adenocarcinoma cells

Tetraspanin protein CD151 is overexpressed in a wide variety of cancer types, including lung cancer, and is closely associated with metastasis and poor prognosis of carcinoma. To investigate whether knockdown of CD151 expression can inhibit the malignant biological behavior of lung adenocarcinoma (LAC), RNA interference technology (RNAi) was used to silence CD151 expression in the A549 LAC cell line. Specific small interfering RNA (siRNA) for targeting human endogenous CD151 were delivered into A549 cells in order to examine the effects on cell proliferation, survival, migration, invasion and colony formation. The expression levels of CD151 were assayed by western blotting, proliferation was evaluated by MTT method and apoptosis was determined by flow cytometry. The invasive and metastatic ability of A549 cells was investigated by wound healing and Boyden chamber assays. Colony formation analysis was used to determine the A549 cell growth properties. Finally, the expression of phosphorylated FAK, PI3K‑AKT, MEK‑Erk1/2, MMPs, and VEGF was detected by western blotting. The results demonstrated that CD151‑siRNA significantly decreased the expression level of CD151 in A549 cells. Reduced CD151 expression in A549 cells lead to the inhibition of cellular proliferation, migration, invasion and colony formation and an enhancement of apoptosis. Furthermore, the expression of tumor development‑related proteins, including FAK, PI3K‑AKT, MEK‑ERK1/2MAPK as well as the expression of MMP9 and VEGF, were restrained. Taken together, the present study has shown that CD151 expression is essential for LAC progression. Thus, knockdown CD151 expression by targeted siRNA could inhibit the related downstream intercellular signaling pathways, and this may provide a novel gene therapy for patients with LAC.