Analysis and evaluation of mitochondrial mirna's in neurofibromatosis TYPE 1 tumor tissue specimens

Neurofibromatosis type 1 (NF1, von Recklinghausen), is an autosomal dominant disease with 1/2500 incidence and occurs symptoms such as café au laits spots, axillary and inguinal freckling, benign tumors with different sizes which are called neurofibroma, and malignant peripheral nerve sheat tumors (MPNST). In addition, tumor development may happen in the spinal cord, cranial nerves, and brain, also bone deformities such as scoliosis. There is no correlation between mutations in NF1 patients and disease phenotype. It shows quite a variety of clinical manifestations. It is also known that the same mutation in the same family has different clinical manifestations. One of the views about these clinical variations is the existence of modifier factors in the NF1 gene. MicroRNAs (miRNAs) are one of these modifier factors. Also, studies in recent years show that changes in mitochondrial function may play a role as modifier factors to NF1 patients' different phenotypes. Mitochondria are important organelles due to their unique signaling pathways and being the energy production center of the cell. In recent years, studies with mitochondria have increased greatly. Mitochondria are known to originate from a bacterium that was taken into the cell by an ancestral anaerobic eukaryotic cell. Mitochondrial physiological processes and possible involvement of bacteria are reviewed with comparative analyses. One of the small non-coding RNA, miRNAs are functioning as post-transcriptional regulators of gene expression. It has been shown that mitochondrial miRNAs (mitomiRs) modulate the mitochondrial genome's translational activation, and regulate mitochondrial protein expression and function. Although mitochondria have been confirmed to be vital for the development, the role of mitomiRs in the crucial biological processes including energy metabolism, oxidative stress, inflammation, and apoptosis has been understood recently. This thesis study aimed to compare the selected 11 mitomiR's isolated from fresh frozen tissues obtained from 11 NF1 patients (1 CALM as a control tissue, 5 cutaneous and 5 plexiform neurofibroma tumor tissues). The expression of these selected mitomiR's were evaluated by quantitative PCR (qRT-PCR) analysis. Even though the results showed an increase in the expression of some mitomiRs based on tumor tissue samples, no significant difference has been detected between cutaneous and plexiform neurofibromas. Regarding the small number of mitomiRs in our study, we concluded that a more elaborated research is required for future studies.