쌍별귀뚜라미는 국내에서 식용 및 파충류의 먹이로 사용되는 중요한 산업곤충으로 알려져있다. 2023년 국내 쌍별귀뚜라미 농가에서 쌍별귀뚜라미 덴소바이러스 감염이 확인되었으며 바이러스 억제제가 요구되는 실정 이다. RNA 간섭(RNAi)은 dsRNA를 이용해 목적 유전자의 발현을 억제할 수 있는 작용기작을 가지며, 바이러스 특이적 시퀀스를 이용한다면 효과적으로 타겟 바이러스의 증식을 저해할 수 있다. 본 연구에서는 덴소바이러스 에 감염된 귀뚜라미에 덴소바이러스 특이적 dsRNA를 제작하여 주입(injection)하고, 바이러스 발현 저해 효과를 관찰했다. 바이러스 감염 수준은 qPCR로 평가하였으며 dsRNA를 접종한 결과 체내 바이러스양이 감소함을 확인 했다. 이 연구는 향후 RNAi를 이용한 쌍별귀뚜라미 덴소바이러스 억제제 개발에 도움이 될 것으로 기대된다.

지난 10년 동안, 이중 가닥 RNA (double-stranded RNA, dsRNA)를 이용한 특정 유전자 발현 간섭(RNA interference, RNAi) 기술은 의약품 개발뿐만 아니라 작물보호 분야에 해충방제부터 익충보호까지 다양하게 그 기술이 사용되어 왔다. 그동안 학계 및 산업체에서 활발히 연 구되어 온 RNAi기술을 이용한 작물 및 익충보호제는 상용화를 눈앞에 두고 있다. 미래 농업 시장에서 해충방제제와 익충보호제로써의 개발을 위한 RNAi의 기술적 응용은 상당한 잠재력을 가지고 있지만, 현장에 직접 사용되기에는 아직 여러 가지 한계점이나 극복해야 할 과제가 남아있 다. 본 리뷰에서는 최근에 활발히 진행되고 있는 작물보호제 및 익충보호제(protection of crops and beneficial insects)로써의 dsRNA의 다양 한 활용과 그 잠재성(potential)을 소개하고자 한다.

Despite existing chemotherapy and surgical resection strategies, salivary gland adenocarcinoma(AdCa NOS) is one of the major causes of mortality among malignant salivary gland tumors. New therapeutic measure are needed to improve the outcome for patients with AdCa. Overexpression of urokinase-type plasminogen activator receptor/urokinase-type plasminogen activator(uPAR-uPA) has been implicated in progression and metastasis of oral cancer. RNA interference(RNAi) which has emerged as an effective method to target specific genes for silencing has provided new opportunities for cancer therapy. But there has been rarely reported using RNAi-uPAR/uPA transfection in salivary gland AdCa. The purpose of this study were to examine the specific inhibition of uPAR/uPA mRNA and protein expression by RNAi transfection of uPAR/uPA through RT-PCR and Immunoslot blot, and to study tumor cell proliferation activity, adhesion, invasion and migration of SGT cell line in vitro compared to the controls. In adhesion assay, cells transfected with RNAi-uPAR/uPA inhibited markedly adhesion to vitronectin compared to parental cells. Angiogenic assays revealed a significant decrease in the angiogenic potential of SGT cells downregulated by both uPAR and uPA. In migration assay, suppressing uPAR and uPA inhibited the capacity of the cells to migrate compared to parental cells. In invasion assay, cells transfected with RNAi-uPAR/uPA showed the maximum decrease in invasion when compared to all other treatment conditions. RNAi expressing plasmids efficiently downregulated mRNA and protein expression of uPAR and uPA. Cell cycle analysis showed that the simultaneous downregulation of uPAR and uPA caused the accumulation of cells in the sub-G0/G1 phase in SGT cells. Immunoslot blot analysis revealed that downregulation of uPAR and uPA caused the prominent activation of caspase 8. It suggested that the RNAi targeting of the uPAR/uPA system could have a therapeutic potentiality for malignant salivary gland tumors.

Frankliniella occidentalis is a major pest in agriculture. Following overuse of insecticides, high resistance has developed due to its high reproduction rate and short generation time. To control the resistant strains of the thrips, the ingestion RNAi- based control was established. A total of 67 genes were selected, and their double-stranded RNAs (dsRNA) were delivered to thrips via the leaf disc-feeding method. Among the genes screened, the dsRNA of Toll-like receptor 6 (TLR6) and coatomer protein subunit epsilon (COPE) resulted in the highest mortality (3.8- and 2.8-fold faster LT50 compared to control, respectively) when ingested by thrips. The dsRNA-fed thrips showed 53% and 83% reduced transcription levels of TLR6 and COPE, respectively. This result demonstrates that the observed mortality of thrips following dsRNA ingestion was due to RNAi, and this lethal genes can be employed as a practical tool to control thrips in the field.