RESUMO
Somatic mutations of mitochondrial DNA (mtDNA) have been reported in different types of cancers and are suggested to play roles in metastasis, cancer development and response to anticancer agents. To predict potential roles of mtDNA alterations in colorectal cancer, we determined the entire mtDNA sequence of eleven human-derived colorectal cancer cell lines and compared with the revised Cambridge Reference Sequence to identify nucleotide alterations. Four homoplasmic and six heteroplasmic alterations were found to be novel. Among them, homoplasmic G6709A (MT-CO1) and G14804A (MT-CYB) alterations cause amino acid changes in the highly conserved residues. Heteroplasmic G1576A (MT-RNR1) and G2975A (MT-RNR2) alterations are expected to make the stem structure of mitochondrial ribosomal RNAs unstable. These nucleotide alterations are candidates that could play important roles in cancer.
Assuntos
DNA Mitocondrial/genética , Proteínas Mitocondriais/genética , Mutação , Sequência de Aminoácidos , Substituição de Aminoácidos , Linhagem Celular Tumoral , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Citocromos b/genética , DNA Mitocondrial/química , Complexo IV da Cadeia de Transporte de Elétrons/genética , Humanos , Dados de Sequência Molecular , Mutação Puntual , Análise de Sequência de DNA , Homologia de Sequência de AminoácidosRESUMO
Malignant fibrous histiocytoma of the liver is an extremely rare tumor. A 43-year-old woman was admitted with an enlargement of the abdomen and a feeling of general fatigue. A clinical examination revealed a right liver giant cystic tumor (18.5 × 22 cm). The cystic tumor, which contained a solid component, occupied almost the entire right lobe of the liver, and a solid S4 tumor was also observed. A blood examination revealed severe anemia and mild liver dysfunction. During hospitalization intratumor bleeding occurred. A right lobectomy of the liver and lymph node dissection was performed after transcatheter arterial embolization. Histopathologically, the tumor was diagnosed as a primary storiform-pleomorphic-type malignant fibrous histiocytoma of the liver. One year after the radical operation, the patient developed recurrences in other organs. She received 17 cycles of chemotherapy with etoposide, ifosfamide, and cisplatin. The recurrent tumors decreased in size, but new recurrences in other organs occurred. The patient died of respiratory failure 4 years and 2 months after the initial operation.