NFκB (RelA) mediates transactivation of hnRNPD in oral cancer cells
Abstract Heterogeneous Ribonucleoprotein D (hnRNPD) is an RNA binding protein involved in post-transcriptional regulation of multiple mediators of carcinogenesis. We previously demonstrated a strong association of hnRNPD over expression with poor outcome in Oral Squamous Cell Carcinoma (OSCC). Howev...
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Nature Portfolio
2022-04-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-022-09963-7 |
| _version_ | 1811272652845744128 |
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| author | Vikas Kumar Anurag Kumar Manish Kumar Moien Rasheed Lone Deepika Mishra Shyam Singh Chauhan |
| author_facet | Vikas Kumar Anurag Kumar Manish Kumar Moien Rasheed Lone Deepika Mishra Shyam Singh Chauhan |
| author_sort | Vikas Kumar |
| collection | DOAJ |
| description | Abstract Heterogeneous Ribonucleoprotein D (hnRNPD) is an RNA binding protein involved in post-transcriptional regulation of multiple mediators of carcinogenesis. We previously demonstrated a strong association of hnRNPD over expression with poor outcome in Oral Squamous Cell Carcinoma (OSCC). However, hitherto the precise molecular mechanism of its overexpression in oral cancer was not clear. Therefore, in an attempt to elucidate the transcriptional regulation of hnRNPD expression, we cloned 1406 bp of 5ʹ flanking region of human hnRNPD gene along with 257 bp of its first exon upstream to promoterless luciferase reporter gene in pGL3-Basic. Transfection of the resulting construct in SCC-4 cells yielded 1271 fold higher luciferase activity over parent vector. By promoter deletion analysis, we identified a canonical TATA box containing 126 bp core promoter region that retained ~ 58% activity of the full length promoter. In silico analysis revealed the presence of four putative NFκB binding motifs in the promoter. Sequential deletion of these motifs from the full-length promoter reporter construct coupled with luciferase assays revealed an 82% decrease in promoter activity after deletion of the first (−1358/−1347) motif and 99% reduction after the deletion of second motif (−1052/−1041). In-vivo binding of NFκB (RelA) to these two motifs in SCC-4 cells was confirmed by ChIP assays. Site directed mutagenesis of even one of these two motifs completely abolished promoter activity, while mutagenesis of the remaining two motifs had marginal effect on the same. Consistent with these findings, treatment of SCC-4 cells with PDTC, a known inhibitor of NFκB dramatically reduced the levels hnRNPD mRNA and protein. Finally, the expression of hnRNPD and NFκB in clinical specimen from 37 oral cancer patients was assessed and subjected to Spearmen’s Correlation analysis which revealed a strong positive correlation between the two. Thus, results of the present study for the first time convincingly demonstrate NFκB (RelA) mediated transcriptional upregulation of hnRNPD expression in oral cancer. |
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| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-04-12T22:44:10Z |
| publishDate | 2022-04-01 |
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| series | Scientific Reports |
| spelling | doaj.art-cf3c3112cf3d469cb3b897abf2b8913e2022-12-22T03:13:37ZengNature PortfolioScientific Reports2045-23222022-04-0112111510.1038/s41598-022-09963-7NFκB (RelA) mediates transactivation of hnRNPD in oral cancer cellsVikas Kumar0Anurag Kumar1Manish Kumar2Moien Rasheed Lone3Deepika Mishra4Shyam Singh Chauhan5Department of Biochemistry, All India Institute of Medical SciencesDepartment of Biochemistry, All India Institute of Medical SciencesDepartment of Biochemistry, All India Institute of Medical SciencesDepartment of Biochemistry, All India Institute of Medical SciencesDivision of Oral Pathology, Centre for Dental Education and Research, All India Institute of Medical SciencesDepartment of Biochemistry, All India Institute of Medical SciencesAbstract Heterogeneous Ribonucleoprotein D (hnRNPD) is an RNA binding protein involved in post-transcriptional regulation of multiple mediators of carcinogenesis. We previously demonstrated a strong association of hnRNPD over expression with poor outcome in Oral Squamous Cell Carcinoma (OSCC). However, hitherto the precise molecular mechanism of its overexpression in oral cancer was not clear. Therefore, in an attempt to elucidate the transcriptional regulation of hnRNPD expression, we cloned 1406 bp of 5ʹ flanking region of human hnRNPD gene along with 257 bp of its first exon upstream to promoterless luciferase reporter gene in pGL3-Basic. Transfection of the resulting construct in SCC-4 cells yielded 1271 fold higher luciferase activity over parent vector. By promoter deletion analysis, we identified a canonical TATA box containing 126 bp core promoter region that retained ~ 58% activity of the full length promoter. In silico analysis revealed the presence of four putative NFκB binding motifs in the promoter. Sequential deletion of these motifs from the full-length promoter reporter construct coupled with luciferase assays revealed an 82% decrease in promoter activity after deletion of the first (−1358/−1347) motif and 99% reduction after the deletion of second motif (−1052/−1041). In-vivo binding of NFκB (RelA) to these two motifs in SCC-4 cells was confirmed by ChIP assays. Site directed mutagenesis of even one of these two motifs completely abolished promoter activity, while mutagenesis of the remaining two motifs had marginal effect on the same. Consistent with these findings, treatment of SCC-4 cells with PDTC, a known inhibitor of NFκB dramatically reduced the levels hnRNPD mRNA and protein. Finally, the expression of hnRNPD and NFκB in clinical specimen from 37 oral cancer patients was assessed and subjected to Spearmen’s Correlation analysis which revealed a strong positive correlation between the two. Thus, results of the present study for the first time convincingly demonstrate NFκB (RelA) mediated transcriptional upregulation of hnRNPD expression in oral cancer.https://doi.org/10.1038/s41598-022-09963-7 |
| spellingShingle | Vikas Kumar Anurag Kumar Manish Kumar Moien Rasheed Lone Deepika Mishra Shyam Singh Chauhan NFκB (RelA) mediates transactivation of hnRNPD in oral cancer cells Scientific Reports |
| title | NFκB (RelA) mediates transactivation of hnRNPD in oral cancer cells |
| title_full | NFκB (RelA) mediates transactivation of hnRNPD in oral cancer cells |
| title_fullStr | NFκB (RelA) mediates transactivation of hnRNPD in oral cancer cells |
| title_full_unstemmed | NFκB (RelA) mediates transactivation of hnRNPD in oral cancer cells |
| title_short | NFκB (RelA) mediates transactivation of hnRNPD in oral cancer cells |
| title_sort | nfκb rela mediates transactivation of hnrnpd in oral cancer cells |
| url | https://doi.org/10.1038/s41598-022-09963-7 |
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