Miaomei Yu1, Yun Xu2, Lili Pan1, Yuehua Feng1, Kaiming Luo3, Qinfeng Mu1, Guanghua Luo4. 1. Comprehensive Laboratory, The Third Affiliated Hospital of Soochow University, Changzhou, China. 2. Gynecology Department, The Third Affiliated Hospital of Soochow University, Changzhou, China. 3. Endocrine Department, The Third Affiliated Hospital of Soochow University, Changzhou, China. 4. Comprehensive Laboratory, The Third Affiliated Hospital of Soochow University, Changzhou, Chinashineroar@163.com.
Abstract
BACKGROUND/AIMS: microRNAs (miRNAs) are known to act as oncogenes or tumor suppressors in diverse cancers. Although miR-10b is an oncogene implicated in many tumors, its role in cervical cancer (CC) remains largely unclear. Here, we investigated the function and underlying mechanisms of miR-10b in human CC. METHODS: Quantitative RT-PCR was used to measure miR-10b expression in CC and normal tissues, and its association with clinicopathologic features was analyzed. Methylation of CpG sites in the miR-10b promoter was analyzed by methylation sequencing. Cell proliferation, apoptosis, migration, and invasion assays were used to elucidate the biological effects of miR-10b and expression of the target gene was assayed with Western blot. RESULTS: miR-10b was downregulated in CC tissues compared with normal tissues, and less miR-10b expression was associated with larger tumors, vascular invasion and HPV-type 16 positivity. miR-10b expression decreased in HeLa (HPV18-positive) and SiHa (HPV16-positive) cells compared with C-33A (HPV-negative), but increased after treatment with 5-Aza-CdR. Methylation ratio of site -797 in the miR-10b promoter in C-33A was lower than that in HeLa and SiHa. Further analysis indicates that site -797 is located within a transcription factor AP-2A (TFAP2A) binding element. Functionally, overexpression of miR-10b in HeLa and SiHa suppressed cell proliferation, migration and invasion, and induced apoptosis and miR-10b downregulation had opposite effects. Mechanistically, T-cell lymphoma invasion and metastasis 1 (Tiam1) was identified as a direct and functional target of miR-10b. CONCLUSION: miR-10b acts as a tumor suppressor in CC by suppressing oncogenic Tiam1, and its expression may be downregulated through methylation of TFAP2A binding element by HPV.
BACKGROUND/AIMS: microRNAs (miRNAs) are known to act as oncogenes or tumor suppressors in diverse cancers. Although miR-10b is an oncogene implicated in many tumors, its role in cervical cancer (CC) remains largely unclear. Here, we investigated the function and underlying mechanisms of miR-10b in human CC. METHODS: Quantitative RT-PCR was used to measure miR-10b expression in CC and normal tissues, and its association with clinicopathologic features was analyzed. Methylation of CpG sites in the miR-10b promoter was analyzed by methylation sequencing. Cell proliferation, apoptosis, migration, and invasion assays were used to elucidate the biological effects of miR-10b and expression of the target gene was assayed with Western blot. RESULTS:miR-10b was downregulated in CC tissues compared with normal tissues, and less miR-10b expression was associated with larger tumors, vascular invasion and HPV-type 16 positivity. miR-10b expression decreased in HeLa (HPV18-positive) and SiHa (HPV16-positive) cells compared with C-33A (HPV-negative), but increased after treatment with 5-Aza-CdR. Methylation ratio of site -797 in the miR-10b promoter in C-33A was lower than that in HeLa and SiHa. Further analysis indicates that site -797 is located within a transcription factor AP-2A (TFAP2A) binding element. Functionally, overexpression of miR-10b in HeLa and SiHa suppressed cell proliferation, migration and invasion, and induced apoptosis and miR-10b downregulation had opposite effects. Mechanistically, T-cell lymphoma invasion and metastasis 1 (Tiam1) was identified as a direct and functional target of miR-10b. CONCLUSION:miR-10b acts as a tumor suppressor in CC by suppressing oncogenic Tiam1, and its expression may be downregulated through methylation of TFAP2A binding element by HPV.
Authors: Hernando Lopez-Bertoni; Amanda Johnson; Yuan Rui; Bachchu Lal; Sophie Sall; Maureen Malloy; Jonathan B Coulter; Maria Lugo-Fagundo; Sweta Shudir; Harmon Khela; Christopher Caputo; Jordan J Green; John Laterra Journal: Signal Transduct Target Ther Date: 2022-02-09
Authors: Jaroslav Nunvar; Lucie Pagacova; Zuzana Vojtechova; Nayara Trevisan Doimo de Azevedo; Jana Smahelova; Martina Salakova; Ruth Tachezy Journal: Biomolecules Date: 2021-05-20