RESUMO
Glioma is the most common and malignant brain tumor with poor prognosis. We investigated the effects of LINC01564 on temozolomide (TMZ) resistance of glioma cells. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect the high expression of LINC01564 in human TMZ-resistant glioma cell lines. Functional experiments verified that LINC01564 and SRSF1 promote the proliferation and TMZ resistance and inhibit the apoptosis of TMZ-treated glioma cells. Iron and ROS detection analyses showed that LINC01564 and SRSF1 suppress ferroptosis in glioma cells. Western blot proved that LINC01564 is positively associated with NFE2L2. Mechanism experiments verified the interaction between SRSF1 and MAPK8 3' UTR. In vitro kinase assays showed that MAPK8 can phosphorylate NFE2L2. Rescue experiments showed that MAPK8 reverses the effect of LINC01564 ablation on cell apoptosis and ferroptosis. Meanwhile, NFE2L2 countervails the effect of MAPK8 ablation on the apoptosis and ferroptosis of glioma cells. Animal experiments proved that LINC01564 and MAPK8 facilitate the TMZ resistance of glioma cells in vivo. In conclusion, LINC01564 promotes the TMZ resistance of glioma cells by upregulating NFE2L2 expression to inhibit ferroptosis, which might offer a new perspective into TMZ treatment of glioma. The diagram of the specific mechanism that LINC01564 promotes the TMZ resistance of glioma cells by upregulating NFE2L2 expression to inhibit ferroptosis.
Assuntos
Neoplasias Encefálicas , Ferroptose , Glioma , Animais , Apoptose/genética , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Resistencia a Medicamentos Antineoplásicos/genética , Glioma/tratamento farmacológico , Glioma/genética , Glioma/metabolismo , Proteína Quinase 8 Ativada por Mitógeno , Temozolomida/farmacologiaRESUMO
Glioma is the most common malignant brain tumour in adults, and the aetiology and mechanism of this tumour remain largely unknown. Previous studies have demonstrated that the long non-coding RNA X-inactive specific transcript (XIST) is upregulated in many cancers, and a high expression level of XIST is associated with poor clinical outcome. In the present study, the expression and function of XIST were investigated in the glioma cell line U251. XIST and microRNA (miR)-133a levels in glioma cell lines were detected by reverse transcription-quantitative polymerase chain reaction. Small hairpin RNA XIST (sh-XIST) and mimics/inhibitor of miR-133a were transfected in glioma cell lines and cell proliferation, invasion, migration and epithelial-mesenchymal transition (EMT) were examined. Luciferase assays were used to verify the associations among XIST, miR-133a and SRY-box (SOX)4. When XIST was knocked down, the proliferation, metastasis and EMT of glioma cells decreased. Notably, downstream genes of SOX4 were also upregulated or downregulated upon sh-XIST treatment. Overexpression of miR-133a inhibited glioma proliferation, metastasis and EMT via reducing the expression of SOX4; in contrast, knockdown of miR-133a exhibited the opposite effect, which revealed that miR-133a negatively regulates glioma progression. Furthermore, using luciferase assays, it was demonstrated that XIST and SOX4 could bind miR-133a in the predicted binding site; XIST competed with SOX4 for miR-133a binding. In conclusion, a XIST/miR-133a/SOX4 axis and a mechanism of XIST glioma in promoting cell proliferation and metastasis were revealed. These findings revealed that XIST has an oncogenic role in the tumourigenesis of glioma and may serve as a potential therapeutic target for glioma.