MicroRNAs (mirs) are small non-coding RNA molecules (~22 nucleotides) that regulate posttranscriptional gene expression. Currently, there has not been a comprehensive study of their role in primary HNSCC. To determine the role of mirs in head and neck squamous cell carcinoma (HNSCC), we screened for altered microRNA expression in HNSCC primary tissue and cell lines. We then further tested the functional impact of alterations of specific mirs. An initial screening of 4 primary HNSCC, 4 normal mucosal controls and 4 HNSCC cell lines were analyzed for mature microRNA expression by microarray. Significance was determined using Significance Analysis of Microarrays (SAM). Nine microRNAs were found by SAM to be up-regulated or down-regulated in tumor tissue including mir-21,let-7,18,29c,142-3p, 155,146b(over-expressed) and 494(under-expressed). Mir-21 was validated by qRT-PCR. Functional validation by growth assays was performed, further validating mir-21. Transfection of mir-21 into JHU-011 and JHU-012 cell lines showed a 39% increase in cell growth at 72 hrs relative to controls (p<.05). Transfection of the inhibitor into JHU-O12 cell lines showed a 92% decrease in cell growth relative to controls at 72hrs (p<.05). In addition, flow cytometry analysis of JHU-012 cells 48 hrs after mir-21 inhibitor transfection showed a statistically significantly increase in cytochrome c release and increased apoptosis. These differentially expressed microRNAs may be of interest as potential novel oncogenes and tumor suppressor genes in HNSCC. Mir-21 is a putative oncogenic microRNA in head and neck cancer.
MicroRNA alterations in head and neck squamous cell carcinoma
POETA, Maria Luana;
2008-01-01
Abstract
MicroRNAs (mirs) are small non-coding RNA molecules (~22 nucleotides) that regulate posttranscriptional gene expression. Currently, there has not been a comprehensive study of their role in primary HNSCC. To determine the role of mirs in head and neck squamous cell carcinoma (HNSCC), we screened for altered microRNA expression in HNSCC primary tissue and cell lines. We then further tested the functional impact of alterations of specific mirs. An initial screening of 4 primary HNSCC, 4 normal mucosal controls and 4 HNSCC cell lines were analyzed for mature microRNA expression by microarray. Significance was determined using Significance Analysis of Microarrays (SAM). Nine microRNAs were found by SAM to be up-regulated or down-regulated in tumor tissue including mir-21,let-7,18,29c,142-3p, 155,146b(over-expressed) and 494(under-expressed). Mir-21 was validated by qRT-PCR. Functional validation by growth assays was performed, further validating mir-21. Transfection of mir-21 into JHU-011 and JHU-012 cell lines showed a 39% increase in cell growth at 72 hrs relative to controls (p<.05). Transfection of the inhibitor into JHU-O12 cell lines showed a 92% decrease in cell growth relative to controls at 72hrs (p<.05). In addition, flow cytometry analysis of JHU-012 cells 48 hrs after mir-21 inhibitor transfection showed a statistically significantly increase in cytochrome c release and increased apoptosis. These differentially expressed microRNAs may be of interest as potential novel oncogenes and tumor suppressor genes in HNSCC. Mir-21 is a putative oncogenic microRNA in head and neck cancer.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
