ABSTRACT
We reported that knockdown of the antisense noncoding mitochondrial RNAs (ASncmtRNAs) induces apoptotic death of several human tumor cell lines, but not normal cells, suggesting this approach for selective therapy against different types of cancer. In order to translate these results to a preclinical scenario, we characterized the murine noncoding mitochondrial RNAs (ncmtRNAs) and performed in vivo knockdown in syngeneic murine melanoma models. Mouse ncmtRNAs display structures similar to the human counterparts, including long double-stranded regions arising from the presence of inverted repeats. Knockdown of ASncmtRNAs with specific antisense oligonucleotides (ASO) reduces murine melanoma B16F10 cell proliferation and induces apoptosis in vitro through downregulation of pro-survival and metastasis markers, particularly survivin. For in vivo studies, subcutaneous B16F10 melanoma tumors in C57BL/6 mice were treated systemically with specific and control antisense oligonucleotides (ASO). For metastasis studies, tumors were resected, followed by systemic administration of ASOs and the presence of metastatic nodules in lungs and liver was assessed. Treatment with specific ASO inhibited tumor growth and metastasis after primary tumor resection. In a metastasis-only assay, mice inoculated intravenously with cells and treated with the same ASO displayed reduced number and size of melanoma nodules in the lungs, compared to controls. Our results suggest that ASncmtRNAs could be potent targets for melanoma therapy. To our knowledge, the ASncmtRNAs are the first potential non-nuclear targets for melanoma therapy.
Subject(s)
Melanoma/therapy , Oligonucleotides, Antisense/genetics , RNA, Untranslated/genetics , Skin Neoplasms/therapy , Animals , Apoptosis , Cell Line, Tumor , Cell Proliferation , Cell Survival , Fibroblasts/metabolism , Humans , Inhibitor of Apoptosis Proteins/metabolism , Melanoma/pathology , Melanoma, Experimental/pathology , Melanoma, Experimental/therapy , Mice , Mice, Inbred C57BL , Mitochondria/pathology , Neoplasm Invasiveness , Neoplasm Metastasis , Repressor Proteins/metabolism , Skin Neoplasms/pathology , SurvivinABSTRACT
The study of RNA and DNA oncogenic viruses has proved invaluable in the discovery of key cellular pathways that are rendered dysfunctional during cancer progression. An example is high risk human papillomavirus (HPV), the etiological agent of cervical cancer. The role of HPV oncogenes in cellular immortalization and transformation has been extensively investigated. We reported the differential expression of a family of human mitochondrial non-coding RNAs (ncRNAs) between normal and cancer cells. Normal cells express a sense mitochondrial ncRNA (SncmtRNA) that seems to be required for cell proliferation and two antisense transcripts (ASncmtRNAs). In contrast, the ASncmtRNAs are down-regulated in cancer cells. To shed some light on the mechanisms that trigger down-regulation of the ASncmtRNAs, we studied human keratinocytes (HFK) immortalized with HPV. Here we show that immortalization of HFK with HPV-16 or 18 causes down-regulation of the ASncmtRNAs and induces the expression of a new sense transcript named SncmtRNA-2. Transduction of HFK with both E6 and E7 is sufficient to induce expression of SncmtRNA-2. Moreover, E2 oncogene is involved in down-regulation of the ASncmtRNAs. Knockdown of E2 in immortalized cells reestablishes in a reversible manner the expression of the ASncmtRNAs, suggesting that endogenous cellular factors(s) could play functions analogous to E2 during non-HPV-induced oncogenesis.
Subject(s)
Cell Transformation, Viral , Gene Expression Regulation , Human papillomavirus 16/metabolism , Human papillomavirus 18/metabolism , Keratinocytes/metabolism , Oncogene Proteins, Viral/metabolism , RNA, Antisense/biosynthesis , RNA, Untranslated/biosynthesis , RNA/biosynthesis , Cell Line, Transformed , Gene Knockdown Techniques , HeLa Cells , Human papillomavirus 16/genetics , Human papillomavirus 18/genetics , Humans , Keratinocytes/pathology , Keratinocytes/virology , Oncogene Proteins, Viral/genetics , RNA/genetics , RNA, Antisense/genetics , RNA, Mitochondrial , RNA, Untranslated/geneticsABSTRACT
Se estudió la incidencia de la infección herpética en 200 mujeres elegidas al azar durante el trabajo de parto, encontrándose 2% de embarazadas excretoras asintomáticas de virus herpes simplex. El estudio serológico de esta población mostró que 96% de ellas presentaba anticuerpos antiherpes, los que fueron transmitidos en niveles semejantes a sus hijos, situación comprobada al estudiar la sangre de cordón. No se detectó caso alguno de herpes neonatal en los recién nacidos de las madres excretoras virales
