Long non-coding RNA MIAT regulates blood tumor barrier permeability by functioning as a competing endogenous RNA

Abstract

Blood–tumor barrier (BTB) presents a major obstacle to brain drug delivery. Therefore, it is urgent to enhance BTB permeability for the treatment of glioma. In this study, we demonstrated that MIAT, ZAK, and phosphorylated NFκB-p65 (p-NFκB-p65) were upregulated, while miR-140-3p was downregulated in glioma-exposed endothelial cells (GECs) of BTB compared with those in endothelial cells cocultured with astrocytes (ECs) of blood–brain barrier (BBB). MIAT inhibited miR-140-3p expression, increased the expression of ZAK, enhanced the ratio of p-NFκB-p65:NFκB-p65, and promoted the endothelial leakage of BTB. Our current study revealed that miR-140-3p was complementary to the ZAK 3′untranslated regions (3′-UTR), and luciferase activity of ZAK was inhibited by miR-140-3p in 293T cells. MiR-140-3p silencing resulted in an increase in BTB permeability by targeting ZAK, while overexpression of miR-140-3p had the opposite results in GECs of BTB. Overexpression of ZAK induced an increase in BTB permeability, and this effect was related to ZAK’s ability to mediate phosphorylation of NFκB-p65. Conversely, ZAK silencing get opposite results in GECs of BTB. As a molecular sponge of miR-140-3p, MIAT attenuated its negative regulation of the target gene ZAK by adsorbing miR-140-3p. P-NFκB-p65 as a transcription factor negatively regulated the expression of TJ-associated proteins by means of chip assay and luciferase assay. Single or combined application of MIAT and miR-140-3p effectively promoted antitumor drug doxorubicin (Dox) across BTB to induce apoptosis of glioma cells. In summary, MIAT functioned as a miR-140-3p sponge to regulate the expression of its target gene ZAK, which contribution to phosphorylation of NFκB-p65 was associated with an increase in BTB permeability by down-regulating the expression of TJ associated proteins, thereby promoting Dox delivery across BTB. These results might provide a novel strategy and target for chemotherapy of glioma.

MiRNA-128-3p Restrains Malignant Melanoma Cell Malignancy by Targeting NTRK3

“…The extraction and quantification of mRNA were performed according to procedures described in our previous study ( 13 ). The PrimeScriptTM RT reagent Kit (TaKaRa, Dalian, China) was used to reverse transcript mRNA into cDNA according to the instructions provided.…”

“…Lipofectamine 3000 (Invitrogen, Foster City, CA, USA) was applied to transfect vectors into A375 and M14 cells according to instructions. G418 (Sigma-Aldrich, St Louis, MO, USA) was used to screen stable transfected cell lines according to procedures described in our previous study ( 13 ).…”

“…Protein extraction and quantification were performed according to procedures described previously in our laboratory ( 13 ). The protein lysate (40 μg) was separated by polyacrylamide gel electrophoresis and then transferred onto a polyvinylidene fluoride membrane.…”

“…MicroRNAs (miRNAs) are a class of non-coding RNAs with 18–25 nucleotides. MiRNAs can inhibit the expression of target genes at the post transcriptional level by binding to 3′ untranslated regions (3′-UTR) of the target gene ( 13 ). As a result, they are critically related to many biological processes such as proliferation, differentiation, apoptosis, and metastasis ( 14 ).…”

Roles of Long Noncoding RNAs in Conferring Glioma Progression and Treatment

“…Li et al showed that silencing HOTAIR could increase BTB permeability by eliminating miR-148b-3p, thereby further reducing the expression of glioma-microvascular endothelial cell tight junction (TJ)-related proteins by targeting USF1 (62). He et al also indicated that MIAT regulated the expression of ZAK to promote the delivery efficiency of doxorubicin across the BTB (63). In addition, the IGF2BP2/ FBXL19-AS1/ZNF765 axis could regulate the permeability of the BTB to improve the antitumor effect of doxorubicin (64).…”