RESUMO
We recently identified the snaR family of small non-coding RNAs that associate in vivo with the nuclear factor 90 (NF90/ILF3) protein. The major human species, snaR-A, is an RNA polymerase III transcript with restricted tissue distribution and orthologs in chimpanzee but not rhesus macaque or mouse. We report their expression in human tissues and their evolution in primates. snaR genes are exclusively in African Great Apes and some are unique to humans. Two novel families of snaR-related genetic elements were found in primates: CAS (catarrhine ancestor of snaR), limited to Old World Monkeys and apes; and ASR (Alu/snaR-related), present in all monkeys and apes. ASR and CAS appear to have spread by retrotransposition, whereas most snaR genes have spread by segmental duplication. snaR-A and snaR-G2 are differentially expressed in discrete regions of the human brain and other tissues, notably including testis. snaR-A is up-regulated in transformed and immortalized human cells, and is stably bound to ribosomes in HeLa cells. We infer that snaR evolved from the left monomer of the primate-specific Alu SINE family via ASR and CAS in conjunction with major primate speciation events, and suggest that snaRs participate in tissue- and species-specific regulation of cell growth and translation.
Assuntos
Evolução Molecular , Pequeno RNA não Traduzido/genética , Elementos Alu , Animais , Sequência de Bases , Linhagem Celular , Linhagem Celular Transformada , Cercopithecidae/genética , Citoplasma/química , Duplicação Gênica , Genômica , Células HeLa , Hominidae/genética , Humanos , Dados de Sequência Molecular , Família Multigênica , Pequeno RNA não Traduzido/análise , Pequeno RNA não Traduzido/metabolismo , Ribossomos/química , Distribuição TecidualRESUMO
Cardiac lymphoma is a rare neoplasm involving heart, pericardium or both, usually seen in immunocompromised patients. We report a 61-year-old male presenting with worsening shortness of breath and 20-pound weight loss. Investigations showed right-sided tumor with interatrial septal wall perforation and left atrial expansion. The diagnosis was confirmed with mediastinal mass biopsy. After receiving the appropriate treatment, there was a steady improvement clinically and on the transesophageal echocardiography.