Progressive miRNA expression profiles in cervical carcinogenesis and identification of HPV‐related target genes for miR‐29

Abstract

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.

microRNA Portraits in Human Vulvar Carcinoma

“…HPV oncogenic proteins E6, E7 and E5 have been shown to directly or indirectly lead to deregulation of multiple miRNAs, including miR-29a in cervical cancer, contributing to the initiation and progression of this cancer (25). MiR-29c, found to be deregulated among our samples, is a member of miR-29 family which has already been shown to restrain cell cycle progression and induce apoptosis while involved in HPV infection -also in cervical cancer (24).…”

“…Therefore, in the present study, normalization was performed using the most stable among our data set, in order to avoid inaccurate expression results. Some studies in other HPV related tumors such as cervical cancer have demonstrated that HPVs have oncogenic properties, mediated at least in part by reshaping the milieu of cellular miRNAs (24). HPV oncogenic proteins E6, E7 and E5 have been shown to directly or indirectly lead to deregulation of multiple miRNAs, including miR-29a in cervical cancer, contributing to the initiation and progression of this cancer (25).…”

“…Decreased expression of miR-223-5p is related to the presence of metastasis in our cases, which corroborates some previously described findings in esophageal tumors: miR-223 targets the artemin (ARTN), a neurotrophic factor which belongs to the family of neurotrophic factors and known to be related to metastasis. Moreover, overexpression of miR-223 in primary gastric tumors has been associated with worse metastasis-free survival and found only in metastatic cells (24).…”

miR-375 Is Down-Regulated in Squamous Cervical Cancer and Inhibits Cell Migration and Invasion via Targeting Transcription Factor SP1

“…Quantitative RT-PCR (qRT-PCR) for miRNA and mRNA was performed as described previously. 11 For miRNA quantification, each reverse transcript reaction consisted of 0.5 g of total RNA, mixed with 2.0 L of 5ϫ RT buffer containing dNTPs (Takara Bio, Otsu, Japan), 0.2 L of 10 mol/L stem-loop RT primer (Invitrogen), 0.2 L RNase inhibitor protein (Takara Bio), and 0.8 L reverse transcriptase (Takara Bio) in a final volume of 10 L, and incubated at 42°C for 60 minutes and at 85°C for 5 minutes. Real-time PCR was performed with an Applied Biosystems 7900HT system (Foster City, CA) using SYBR Premix Ex Taq (Takara Bio).…”

“…In a previous study, we screened the different expression of miRNAs between cervical normal and cancer tissues through miRNA array and found that miR-375 was remarkably down-regulated in cervical cancer tissues, compared with normal tissues, 11 which implies that miR-375 may participate in the pathogenesis and development of cervical cancer. In the present study, we examined miR-375 expression in cervical cancer tissues and investigated the function of miR-375 in proliferation, migration, and invasion of cervical cancer cells, and we identified SP1 as a target gene for miR-375.…”