ORIGINAL PAPER Expression of microRNAs in tumors of the central nervous system in pediatric patients in México Pilar Eguía-Aguilar 1 & Lisette Gutiérrez-Castillo 1,2 & Mario Pérezpeña-Díazconti 1 & Jeanette García-Chéquer 1 & Jorge García-Quintana 1 & Fernando Chico-Ponce de León 3 & Luis Gordillo-Domínguez 3 & Samuel Torres-García 3 & Francisco Arenas-Huertero 2,4 Received: 3 January 2017 /Accepted: 4 August 2017 # Springer-Verlag GmbH Germany 2017 Abstract Purpose MicroRNAs were identified as molecules that par- ticipate in gene regulation; alterations in their expression char- acterize central nervous system (CNS). Information in pediat- rics is scarce, so the objective of this work was to determine and then compare the patterns of expression of microRNAs in astrocytomas, ependymomas, and medulloblastomas, as well as in non-neoplastic brain. Methods Low-density arrays were utilized to evaluate 756 microRNAs in three samples of each type of tumor and non- neoplastic brain. The relative expression was calculated in order to identify the three microRNAs whose expression was modified notably. This was verified using RT-qPCR in more number of tumor samples. Results The microRNAs selected for testing were miR-100- 5p, miR-195-5p, and miR-770-5p. A higher expression of miR-100-5p was observed in the astrocytomas and ependymomas compared to the medulloblastomas: on average 3.8 times (p < 0.05). MiR-770-5p was expressed less in me- dulloblastomas compared to astrocytomas four times ( p = 0.0162). MiR-195-5p had a low expression in medulloblastomas compared to non-neoplastic cerebellum (p = 0.049). In all three tumor types, expression of miR-770- 5p was lower than in non-neoplastic brain (p < 0.001). Conclusions These microRNAs may represent potential markers in these tumors. Keywords Epigenetic . Astrocytomas . Ependymomas . Medulloblastomas . Expression array Introduction Central nervous system tumors, CNST, belong to a particular- ly large and diverse group and almost 100 different types that have been described [7]. These tumors are still classified by anatomical location, clinical status, and the histopathological characteristics of the lesion [29]. Gliomas, for example, have characteristic genetic alterations are now allowing researchers to subdivide patients according to molecular patterns associ- ated with greater survival [11]. In medulloblastomas, in addi- tion to the histopathological classification, the molecular cat- egorization based on different pathways—such as wingless (Wnt) or sonic hedgehog (Shh)—allows them to be recog- nized as tumors that best respond to treatment [8], thus open- ing research areas for the development of drugs that can in- hibit these pathways [30]. The panorama in ependymomas is even less clear because of their marked genetic heterogeneity and the absence of distinguishable groups of genetic alter- ations that could orient patient management [31]. These facts emphasize the need to design and conduct more profound studies of the molecular biology of these types of tumors, especially in children [7]. For years, work has focused at the genetic level, but it is now clear that the epigenetic level ex- ercises significant regulation. One such epigenetic regulator that acts at the level of the cytoplasm is performed by * Francisco Arenas-Huertero farenashuertero@yahoo.com.mx 1 Departmento de Patología Clínica y Experimental, Hospital Infantil de México Federico Gómez, Ciudad de México, México 2 Facultad de Ciencia y Tecnología, Universidad Simón Bolívar, Ciudad de México, México 3 Departmento de Neurocirugía, Hospital Infantil de México Federico Gómez, Ciudad de México, México 4 Laboratorio de Investigación en Patología Experimental, Hospital Infantil de México Federico Gómez-Instituto Nacional de Salud, Dr. Márquez 162, Colonia Doctores, Delegación Cuauhtémoc, 06720 Ciudad de México, México Childs Nerv Syst DOI 10.1007/s00381-017-3569-9