Microarray Expression Profiles and bioinformatics analysis of mRNAs, lncRNAs and circRNAs in the secondary temozolomide-resistant glioblastoma

Glioblastoma multiforme (GBM) is the most common and aggressive primary human brain tumor. Although comprehensive therapies combining radiotherapy and chemotherapy after surgery can prolong survival, the prognosis is still poor with a median survival of only 14.6 months. Chemoresistance is one of the major causes of relapse as well as poor survival in glioma patients. Therefore, novel strategies to overcome chemoresistance are desperately needed for improved treatment of human GBM. Recent studies have demonstrated that long non‑coding RNAs are closely related to resistance to cancer chemotherapy. Here, we simultaneously detected, for the first time, the expression profiles of mRNAs, lncRNAs, and circRNAs in three pairs of secondary temozolomide-resistant glioblastoma (STRG) and matched primary glioblastoma tissues by microarrays. A total of 92 mRNA, 299lncRNAs, and 53 circRNAs were altered during the Chemoresistance. The functions of these differentially expressed RNAs were predicted by Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Co-expression networks of lncRNA-mRNA and circRNA-miRNA were conducted to uncovered the hidden ceRNA mechanisms. Our findings revealed the alteration of expression patterns of mRNAs, lncRNAs, and circRNAs in the secondary temozolomide-resistant glioblastoma. These mRNAs, lncRNAs, and circRNAs might be potential therapeutic targets for the treatment of glioblastoma. The STRG samples included the standard resection of GBM performed on these patients and treatment with a 100 mg / (m2 d) dose of temozolomide was applied for the postoperative period. These patients underwent surgery again owing to GBM recurrence, and the daily dose of temozolomide was increased to 200 mg / (m2 d), postoperatively