Combining genomic analyses with tumour-derived slice cultures for the characterization of an EGFR-activating kinase mutation in a case of glioblastoma

Recent advances in organotypic tissue slice cultures for anticancer drug development

Organotypic tissue slice culture is established from animal or patient tissues and cultivated in an in vitro ecosystem. This technique has made countless contributions to anticancer drug development due to the vast number of advantages, such as the preservation of the cell repertoire and immune components, identification of invasive ability of tumors, toxicity determination of compounds, quick assessment of therapeutic efficacy, and high predictive performance of drug responses. Importantly, it serves as a reliable tool to stratify therapeutic responders from nonresponders and select the optimal standard-of-care treatment regimens for personalized medicine, which is expected to become a potent platform and even the gold standard for anticancer drug screening of individualization in the near future.

Mutational pressure and natural selection in epidermal growth factor receptor gene during germline and somatic mutagenesis in cancer cells

In this study we investigated nucleotide usage biases along the length of a gene encoding human epidermal growth factor receptor (EGFR) and found out that there had been mutational GC-pressure with stronger asymmetric C-pressure in that gene before the preferable direction of nucleotide mutations changed. Current preferable direction of germline mutations in EGFR gene has been estimated with the help of Ensembl data base of gene variations. Preferable direction of somatic mutations in EGFR gene from cancer cells has been estimated with the help of COSMIC data base. Both germline and somatic mutations in cancer cells have the same GC to AT preferable direction in EGFR gene. These data have been used with the aim to find fragments of EGFR gene that have lower probability of missense C to T and G to A transitions to occur. So, the less mutable parts of extracellular EGFR domain are: C-terminal part of the first beta barrel and the central part of the second beta barrel. The less mutable parts of tyrosine kinase EGFR domain are: ATP-binding site (partially), regulatory alpha helix, and fragments that change their secondary structure during the activation process. These parts of EGFR should be considered as the best targets for new types of therapy development. Such criterion as low mutability is especially important for the selection of targets for anti-tumor therapy, since we have detected positive selection of amino acid replacements during somatic mutagenesis of EGFR gene in cancer cells.

Identification of survival‑associated key genes and long non‑coding RNAs in glioblastoma multiforme by weighted gene co‑expression network analysis

Glioblastoma multiforme (GBM) is the most common and aggressive primary malignant brain tumour. However, the causes of GBM are not clear, and the prognosis remains poor. The aim of the present study was to elucidate the key coding genes and long non‑coding RNAs (lncRNAs) associated with the survival time of GBM patients by obtaining the RNA expression profiles from the Chinese Glioma Genome Atlas database and conducting weighted gene co‑expression network analysis. Modules associated with overall survival (OS) were identified, and Gene Ontology and pathway enrichment analyses were performed. The hub genes of these modules were validated via survival analysis, while the biological functions of crucial lncRNAs were also analysed in the publicly available data. The results identified a survival‑associated module with 195 key genes. Among them, 33 key genes were demonstrated to be associated with OS, and the majority of these were involved in extracellular matrix‑associated and tyrosine kinase receptor signalling pathways. Furthermore, LOC541471 was identified as an OS‑associated lncRNA, and was reported to be involved in the oxidative phosphorylation of GBM with pleckstrin‑2. These findings may significantly enhance our understanding on the aetiology and underlying molecular events of GBM, while the identified candidate genes may serve as novel prognostic markers and potential therapeutic targets for GBM.