Long non-coding RNA CASC2 targeting miR-18a suppresses glioblastoma cell growth, metastasis and EMT in vitro and in vivo

Long non-coding RNAs (lncRNAs) cancer susceptibility candidate 2 (CASC2) has been characterized as atumor suppressor in glioma. Although CASC2 may predict the prognosis of glioma patients, the role andmechanism of CASC2 in human glioblastoma remain to be fully illuminated. Expression of CASC2 and miR18a was detected using RT-qPCR. Cell growth was evaluated by MTT assay, colony formation assay, and flowcytometry; metastasis and epithelial-mesenchymal transition (EMT) were determined with transwell assay andWestern blot, respectively. The target binding between CASC2 and miR-18a was predicted on Starbasesoftware, and confirmed by luciferase reporter assay and RNA immunoprecipitation. Xenograft experimentmeasured tumor growth. As a result, CASC2 was downregulated and miR-18a was upregulated in glioblastomatumor tissues and cells (T98 and A172). Overexpression of CASC2 promoted apoptosis rate and E-cadherinexpression, but suppressed cell viability, colony-forming ability, migration, invasion, and expression ofN-cadherin and Vimentin in T98 and A172 cells, accompanied with tumor growth inhibition in vivo; whereas,silencing of CASC2 exerted the opposite effect on cell growth, metastasis and EMT of T98 and A172 cellsin vitro. However, reintroduction of miR-18a could reverse CASC2 upregulation-mediated suppression onabove cell behaviors in vitro. More importantly, miR-18a was a downstream target for CASC2, and wasnegatively regulated by CASC2. Collectively, this study demonstrated that CASC2 served as tumor suppressorin glioblastoma by inhibiting cell growth, metastasis and EMT both in vitro and in vivo partially via CASC2-miR-18a axis.

Identification and characterization of a gene encoding a putative lysophosphatidyl acyltransferase from Arachis hypogaea.

Lysophosphatidyl acyltransferase (LPAT) is the important enzyme responsible for the acylation of lysophosphatidic acid (LPA), leading to the generation of phosphatidic acid (PA) in plant. Its encoding gene is an essential candidate for oil crops to improve oil composition and increase seed oil content through genetic engineering. In this study, a fulllength AhLPAT4 gene was isolated via cDNA library screening and rapid amplification of cDNA ends (RACE); our data demonstrated that AhLPAT4 had 1631 nucleotides, encoding a putative 43.8 kDa protein with 383 amino acid residues. The deduced protein included a conserved acyltransferase domain and four motifs (I–IV) with putative LPA and acyl-CoA catalytic and binding sites. Bioinformatic analysis indicated that AhLPAT4 contained four transmembrane domains (TMDs), localized to the endoplasmic reticulum (ER) membrane; detailed analysis indicated that motif I and motifs II–III in AhLPAT4 were separated by the third TMD, which located on cytosolic and ER luminal side respectively, and hydrophobic residues on the surface of AhLPAT4 protein fold to form a hydrophobic tunnel to accommodate the acyl chain. Subcellular localization analysis confirmed that AhLPAT4 was a cytoplasm protein. Phylogenetic analysis revealed that AhLPAT4 had a high homology (63.7–78.3%) with putative LPAT4 proteins from Glycine max, Arabidopsis thaliana and Ricinus communis. AhLPAT4 was ubiquitously expressed in diverse tissues except in flower, which is almost undetectable. The expression analysis in different developmental stages in peanut seeds indicated that AhLPAT4 did not coincide with oil accumulation.