Analysis of Post-transcriptional Gene Regulation of Nod-Like Receptors via the 3'UTR

lncRNA FLVCR-AS1 promotes osteosarcoma growth by targeting miR381-3p/CCND1

Purpose

This article reports on FLVCR-AS1 effects on osteosarcoma (OS) growth.

Methods

Tumor tissue and adjacent normal tissue of 48 OS patients were collected. HOS and 143B cells were transfected. Gene expression was examined with qRT-PCR and Western blot. CCK8 assays and cell cloning was performed to measure cell proliferation. Cell cycle and apoptosis were assessed. Luciferase-reporter gene assays and RNA pull-down tests were used to detect targeting relationships between genes.

Results

Prominently higher FLVCR-AS1 expression was found in OS tissue and cells, and was associated with poor prognosis (P<0.05, P<0.01, or P<0.001). Compared with the siCtrl group, 143B and HOS cells of the siFLVCR-AS1 group had significantly lower OD₄₅₀ values and clone numbers and obviously higher percentages of cells in the G₁ phase and apoptosis (P<0.01 or P<0.001). miR381-3p expression was directly inhibited by FLVCR-AS1, and CCND1 expression was directly suppressed by miR381-3p. Compared with the FLVCR-AS1 group, 143B cells of the FLVCR-AS1⁺ miR381-3p mimic group and FLVCR-AS1⁺ siCCND1 group showed remarkably lower OD₄₅₀ values and clone numbers obviously higher apoptosis and percentage of cells in the G₁ phase (P<0.05, P<0.01, or P<0.001).

Conclusion

FLVCR-AS1 promoted OS growth by upregulating CCND1 expression via downregulation of miR381-3p.

Identification of Novel Compounds Enhancing SR-BI mRNA Stability through High-Throughput Screening

Atherosclerosis is the pathological basis of most cardiovascular diseases. Reverse cholesterol transport (RCT) is a main mechanism of cholesterol homeostasis and involves the direct transport of high-density lipoprotein (HDL) cholesteryl ester by selective cholesterol uptake. Hepatic scavenger receptor class B member 1 (SR-BI) overexpression can effectively promote RCT and reduce atherosclerosis. SR-BI may be an important target for prevention or treatment of atherosclerotic disease. In our study, we inserted human SR-BI mRNA 3' untranslated region (3'UTR) downstream of the luciferase reporter gene, to establish a high-throughput screening model based on stably transfected HepG2 cells and to screen small-molecule compounds that can significantly enhance the mRNA stability of the SR-BI gene. Through multiple screenings of 25 755 compounds, the top five active compounds that have similar structures were obtained, with a positive rate of 0.19%. The five positive compounds could enhance the SR-BI expression and uptake of DiI-HDL in the hepatocyte HepG2. E238B-63 could also effectively extend the half-life of SR-BI mRNA and enhance the SR-BI mRNA and protein level and the uptake of DiI-HDL in hepatocytes in a time-dependent and dose-dependent manner. The structure-activity relationship analysis showed that the structure N-(3-hydroxy-2-pyridyl) carboxamide is possibly the key pharmacophore of the active compound, providing reference for acquiring candidate compounds with better activity. The positive small molecular compounds obtained in this study might become new drug candidates or lead compounds for the treatment of cardiovascular diseases and contribute to the further study of the posttranscriptional regulation mechanism of the SR-BI gene.