RESUMO
Long noncoding RNAs (lncRNAs) play diverse roles in biological processes, but their expression profiles and functions in cervical carcinogenesis remain unknown. By RNA-sequencing (RNA-seq) analyses of 18 clinical specimens and selective validation by RT-qPCR analyses of 72 clinical samples, we provide evidence that, relative to normal cervical tissues, 194 lncRNAs are differentially regulated in high-risk (HR)-HPV infection along with cervical lesion progression. One such lncRNA, lnc-FANCI-2, is extensively characterized because it is expressed from a genomic locus adjacent to the FANCI gene encoding an important DNA repair factor. Both genes are up-regulated in HPV lesions and in in vitro model systems of HR-HPV18 infection. We observe a moderate reciprocal regulation of lnc-FANCI-2 and FANCI in cervical cancer CaSki cells. In these cells, lnc-FANCI-2 is transcribed from two alternative promoters, alternatively spliced, and polyadenylated at one of two alternative poly(A) sites. About 10 copies of lnc-FANCI-2 per cell are detected preferentially in the cytoplasm. Mechanistically, HR-HPVs, but not low-risk (LR)-HPV oncogenes induce lnc-FANCI-2 in primary and immortalized human keratinocytes. The induction is mediated primarily by E7, and to a lesser extent by E6, mostly independent of p53/E6AP and pRb/E2F. We show that YY1 interacts with an E7 CR3 core motif and transactivates the promoter of lnc-FANCI-2 by binding to two critical YY1-binding motifs. Moreover, HPV18 increases YY1 expression by reducing miR-29a, which targets the 3' untranslated region of YY1 mRNA. These data have provided insights into the mechanisms of how HR-HPV infections contribute to cervical carcinogenesis.
Assuntos
Proteínas de Grupos de Complementação da Anemia de Fanconi/genética , Papillomavirus Humano 16/genética , MicroRNAs/genética , Infecções por Papillomavirus/genética , RNA Longo não Codificante/genética , Neoplasias do Colo do Útero/genética , Fator de Transcrição YY1/genética , Processamento Alternativo , Sequência de Bases , Carcinogênese/genética , Carcinogênese/metabolismo , Carcinogênese/patologia , Linhagem Celular Tumoral , Colo do Útero/metabolismo , Colo do Útero/patologia , Colo do Útero/virologia , Fatores de Transcrição E2F/genética , Fatores de Transcrição E2F/metabolismo , Proteínas de Grupos de Complementação da Anemia de Fanconi/metabolismo , Feminino , Regulação da Expressão Gênica , Interações Hospedeiro-Patógeno/genética , Papillomavirus Humano 16/metabolismo , Papillomavirus Humano 16/patogenicidade , Papillomavirus Humano 18/genética , Papillomavirus Humano 18/metabolismo , Papillomavirus Humano 18/patogenicidade , Humanos , Queratinócitos/metabolismo , Queratinócitos/patologia , Queratinócitos/virologia , MicroRNAs/metabolismo , Proteínas E7 de Papillomavirus/genética , Proteínas E7 de Papillomavirus/metabolismo , Infecções por Papillomavirus/metabolismo , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , Regiões Promotoras Genéticas , RNA Longo não Codificante/metabolismo , Proteína do Retinoblastoma/genética , Proteína do Retinoblastoma/metabolismo , Transdução de Sinais , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia , Fator de Transcrição YY1/metabolismoRESUMO
miRNAs have the potential to act on diverse downstream genes, and miRNA signatures of HPV-infected tissues may provide insight into HPV-related carcinogenesis. We set out to profile miRNA expression in HPV-infected samples and relate this to histological and grade-specific alterations in the spectrum of cervical carcinogenesis in vivo. A total of 31 miRNAs showed significant and continuous expression along with the progression from normal cervical tissue to cancer, and six of them were validated in 133 samples. By bioinformatics analyses, we established a putative HPV-associated miRNA-mRNA regulatory network, showing that miR-29 is the most highly enriched. We also found that YY1 and CDK6 were both positively correlated with E6/E7 RNA expression and targeted by tumour-suppressive miR-29. Evidence of miR-29 involvement in HPV infection was further verified in patient samples and by various experimental approaches. Taken together, our results suggest that HPVs have oncogenic properties at least in part by reshaping the milieu of cellular miRNAs. miR-29 restrains cell cycle progression and induces apoptosis via YY1 and CDK6 promoting malignant transformation induced by HPV, although the abnormality of miR-29 in HPV-infected cells might be regulated in an indirect way.