A ceRNA Circuitry Involving the Long Noncoding RNA Klhl14-AS, Pax8, and Bcl2 Drives Thyroid Carcinogenesis
CANCER RESEARCH
Authors: Credendino, Sara C.; Bellone, Maria L.; Lewin, Nicole; Amendola, Elena; Sanges, Remo; Basu, Swaraj; Sepe, Romina; Decaussin-Petrucci, Myriam; Tinto, Nadia; Fusco, Alfredo; De Felice, Mario; De Vita, Gabriella
Abstract
Klhl14-AS is a long noncoding RNA expressed since early specification of thyroid bud and is the most enriched gene in the mouse thyroid primordium at E10.5. Here, we studied its involvement in thyroid carcinogenesis by analyzing its expression in cancer tissues and different models of neoplastic transformation. Compared with normal thyroid tissue and cells, Klhl14-AS was significantly downregulated in human thyroid carcinoma tissue specimens, particularly the anaplastic histotype, thyroid cancer cell lines, and rodent models of thyroid cancer. Downregulating the expression of Klhl14-AS in normal thyroid cells decreased the expression of thyroid differentiation markers and cell death and increased cell viability. These effects were mediated by the binding of Klhl14-AS to two miRNAs, Mir182-5p and Mir20a-5p, which silenced Pax8 and Bcl2, both essential players of thyroid differentiation. MIR182-5p and MIR20a-5p were upregulated in human thyroid cancer and thyroid cancer experimental models and their effects on Pax8 and Bcl2 were rescued by Klhl14-AS overexpression, confirming Klhl14-AS as a ceRNA for both Pax8 and Bcl2. This work connects deregulation of differentiation with increased proliferation and survival in thyroid neoplastic cells and highlights a novel ceRNA circuitry involving key regulators of thyroid physiology. Significance: This study describes a new ceRNA with potential tumor suppression activity and helps us better understand the regulatory mechanisms during thyroid differentiation and carcinogenesis.
The mutational pattern of primary lymphoma of the central nervous system determined by whole-exome sequencing
LEUKEMIA
Authors: Vater, I.; Montesinos-Rongen, M.; Schlesners, M.; Haakel, A.; Purschke, F.; Sprute, R.; Mettenmeyer, N.; Nazzal, I.; Nagel, I.; Gutwein, J.; Richter, J.; Buchhalter, I.; Russell, R. B.; Wiestler, O. D.; Eils, R.; Deckert, M.; Siebert, R.
Abstract
To decipher the mutational pattern of primary CNS lymphoma (PCNSL), we performed whole-exome sequencing to a median coverage of 103 x followed by mutation verification in 9 PCNSL and validation using Sanger sequencing in 22 PCNSL. We identified a median of 202 (range: 139-251) potentially somatic single nucleotide variants (SNV) and 14 small indels (range: 7-22) with potentially protein-changing features per PCNSL. Mutations affected the B-cell receptor, toll-like receptor, and NF-kappa B and genes involved in chromatin structure and modifications, cell-cycle regulation, and immune recognition. A median of 22.2% (range: 20.0-24.7%) of somatic SNVs in 9 PCNSL overlaps with the RGYW motif targeted by somatic hypermutation (SHM); a median of 7.9% (range: 6.2-12.6%) affects its hotspot position suggesting a major impact of SHM on PCNSL pathogenesis. In addition to the well-known targets of aberrant SHM (aSHM) (PIM1), our data suggest new targets of aSHM (KLHL14, OSBPL10, and SUSD2). Among the four most frequently mutated genes was ODZ4 showing protein-changing mutations in 4/9 PCNSL. Together with mutations affecting CSMD2, CSMD3, and PTPRD, these findings may suggest that alterations in genes having a role in CNS development may facilitate diffuse large B-cell lymphoma manifestation in the CNS. This may point to intriguing mechanisms of CNS tropism in PCNSL.