Long noncoding RNA landscapes specific to benign and malignant thyroid neoplasms of distinct histological subtypes.

The main types of thyroid neoplasms, follicular adenoma (FA), follicular thyroid carcinoma (FTC), classical and follicular variants of papillary carcinoma (clPTC and fvPTC), and anaplastic thyroid carcinoma (ATC), differ in prognosis, progression rate and metastatic behaviour. Specific patterns of lncRNAs involved in the development of clinical and morphological features can be presumed. LncRNA landscapes within distinct benign and malignant histological variants of thyroid neoplasms were not investigated. The aim of the study was to discover long noncoding RNA landscapes common and specific to major benign and malignant histological subtypes of thyroid neoplasms. LncRNA expression in FA, FTC, fvPTC, clPTC and ATC was analysed with comprehensive microarray and RNA-Seq datasets. Putative biological functions were evaluated via enrichment analysis of coexpressed coding genes. In the results, lncRNAs common and specific to FTC, clPTC, fvPTC, and ATC were identified. The discovered lncRNAs are putatively involved in L1CAM interactions, namely, pre-mRNA processing (lncRNAs specific to FTC); PCP/CE and WNT pathways (lncRNAs specific to fvPTC); extracellular matrix organization (lncRNAs specific to clPTC); and the cell cycle (lncRNAs specific to ATC). Known oncogenic and suppressor lncRNAs (RMST, CRNDE, SLC26A4-AS1, NR2F1-AS1, and LINC00511) were aberrantly expressed in thyroid carcinomas. These findings enhance the understanding of lncRNAs in the development of subtype-specific features in thyroid cancer.

Gene Expression Profiling Revealed 2 Types of Bronchial Basal Cell Hyperplasia and Squamous Metaplasia With Different Progression Potentials.

The premalignant process preceding squamous cell lung cancer is not inevitable; it can stop at any of the bronchial lesions: basal cell hyperplasia (BCH), squamous metaplasia (SM), and dysplasia and then progress or regress. At present, the mechanisms underlying the progression of the bronchial lesions remain undefined. Previously, we hypothesized that bronchial lesions that presented individually or combined with each other in the bronchi of lung cancer patients mirror the different "scenarios" of the premalignant process: individual BCH-the stoppage at the stage of hyperplasia, BCH plus SM-the progression of hyperplasia to metaplasia, and SM plus dysplasia-the progression of metaplasia to dysplasia. In this study, we analyzed gene expression profiles of BCH, SM, and dysplasia depending on their cooccurrence in the bronchi of lung cancer patients. The immune response gene expression was found to be a key difference between the individual BCH and BCH combined with SM lesions and a potential mechanism that determines the progression of hyperplasia to metaplasia. Upregulation of the cell cycle and downregulation of the cilium assembly genes mainly distinguished SM that copresented with dysplasia from SM that copresented with BCH and is a probable mechanism of the progression of metaplasia to dysplasia. Dysplasia showed mainly overexpression of the cell division genes and underexpression of the inflammation genes. Thus, this study demonstrates the significant gene expression differences between the premalignant lesions depending on their cooccurrence in the bronchi and sheds light on the mechanisms of the precancerous process preceding squamous cell lung cancer.

P.F508del editing in cells from cystic fibrosis patients.

Development of genome editing methods created new opportunities for the development of etiology-based therapies of hereditary diseases. Here, we demonstrate that CRISPR/Cas9 can correct p.F508del mutation in the CFTR gene in the CFTE29o- cells and induced pluripotent stem cells (iPSCs) derived from patients with cystic fibrosis (CF). We used several combinations of Cas9, sgRNA and ssODN and measured editing efficiency in the endogenous CFTR gene and in the co-transfected plasmid containing the CFTR locus with the p.F508del mutation. The non-homologous end joining (NHEJ) frequency in the CFTR gene in the CFTE29o- cells varied from 1.25% to 2.54% of alleles. The best homology-directed repair (HDR) frequency in the endogenous CFTR locus was 1.42% of alleles. In iPSCs, the NHEJ frequency in the CFTR gene varied from 5.5% to 12.13% of alleles. The best HDR efficacy was 2.38% of alleles. Our results show that p.F508del mutation editing using CRISPR/Cas9 in CF patient-derived iPSCs is a relatively rare event and subsequent cell selection and cultivation should be carried out.

Exome, transcriptome and miRNA analysis don't reveal any molecular markers of TKI efficacy in primary CML patients.

BACKGROUND: Approximately 5-20% of chronic myeloid leukemia (CML) patients demonstrate primary resistance or intolerance to imatinib. None of the existing predictive scores gives a good prognosis of TKI efficacy. Gene polymorphisms, expression and microRNAs are known to be involved in the pathogenesis of TKI resistance in CML. The aim of our study is to find new molecular markers of TKI therapy efficacy in CML patients. METHODS: Newly diagnosed patients with Ph+ CML in chronic phase were included in this study. Optimal and non-optimal responses to TKI were estimated according to ELN 2013 recommendation. We performed genotyping of selected polymorphisms in 62 blood samples of CML patients, expression profiling of 33 RNA samples extracted from blood and miRNA profiling of 800 miRNA in 12 blood samples of CML patients. RESULTS: The frequencies of genotypes at the studied loci did not differ between groups of patients with an optimal and non-optimal response to TKI therapy. Analysis of the expression of 34,681 genes revealed 26 differently expressed genes (p < 0.05) in groups of patients with different TKI responses, but differences were very small and were not confirmed by qPCR. Finally, we did not find difference in miRNA expression between the groups. CONCLUSIONS: Using modern high-throughput methods such as whole-exome sequencing, transcriptome and miRNA analysis, we could not find reliable molecular markers for early prediction of TKI efficiency in Ph+ CML patients.

Gene Fusions in Thyroid Cancer.

BACKGROUND: Gene fusions are known in many cancers as driver or passenger mutations. They play an important role in both the etiology and pathogenesis of cancer and are considered as potential diagnostic and prognostic markers and possible therapeutic targets. The spectrum and prevalence of gene fusions in thyroid cancer ranges from single cases up to 80%, depending on the specific type of cancer. During last three years, massive parallel sequencing technologies have revealed new fusions and allowed detailed characteristics of fusions in different types of thyroid cancer. SUMMARY: This article reviews all known fusions and their prevalence in papillary, poorly differentiated and anaplastic, follicular, and medullary carcinomas. The mechanisms of fusion formation are described. In addition, the mechanisms of oncogenic transformation, such as altered gene expression, forced oligomerization, and subcellular localization, are given. CONCLUSION: The prognostic value and perspectives of the utilization of gene fusions as therapeutic targets are discussed.