Document Type
Article
Abstract
Abstract
Background
A variety of pathways target CDKI p21WAF1/CIP1 expression at transcriptional, post-transcriptional as well as translational levels. We previously found that cell growth suppressing retinoid CD437 enhanced expression of p21WAF1/CIP1 and DNA damage inducible GADD45 proteins in part by elevating their mRNA stability.
Results
Here, we investigated molecular mechanisms of CD437-dependent post-transcriptional regulation of p21WAF1/CIP1 expression. By utilizing MDA-MB-468 HBC cells expressing chimeric rabbit β-globin-p21WAF1/CIP1 transcripts we mapped multiple CD437-responsive sequences located within positions 1195 to 1795 of the 3'-untranslated region of p21WAF1/CIP1 mRNA. Several cytoplasmic proteins present in MDA-MB-468, MCF-7 HBC as well as HL-60R leukemia cells bound specifically, in vitro, with these CD437-responsive sequences. CD437 treatment of cells resulted in elevated binding of ~85 kD and ~55 kD cytoplasmic proteins with putative CD437-responsive sequences. A 12 nt RNA sequence (5'-UGUGGUGGCACA-3') present within CD437-responsive region of p21WAF1/CIP1 mRNA displayed specific and elevated binding with the above noted proteins. Treatment of cells with ActD or CHX prior to CD437 exposure did not abrogate RNA-protein interactions. However, treatment of cytoplasmic protein extracts with proteinase K or alkaline phosphatase resulted in loss of RNA-protein interactions.
Conclusions
CD437 regulates cell growth in part by regulating stability of p21WAF1/CIP1 mRNA that involves specific RNA-protein interactions that are phosphorylation-dependent, while not requiring nascent transcription or protein synthesis.
Disciplines
Oncology | Surgery
Recommended Citation
Zhang et al.: Novel cis-trans interactions are involved in post-transcriptional regulation of cyclin-dependent kinase inhibitor p21WAF1/CIP1 mRNA. Journal of Molecular Signaling 2010 5:12. Received: 8 July 2010 Accepted: 12 August 2010 Published: 12 August 2010 References 1. 2. 3. 4. 5. 6. El-Deiry WS, Tokino T, Velculescu T, Levy DB, Parsons R, Trent JM, Lin D, Mercer WE, Kinzler KW, Vogelstein B: Waf1, a potential mediator of p53 tumor supression. Cell 1993, 75:817-825. Gorospe M, Wang X, Holbrook NJ: Functional role of p21 during the cellular response to stress. Gene Expression 1999, 7:377-385. Timchenko NA, Wilde M, Nakanishi M, Smith JR, Darlington GJ: CCAAT/ enhancer-binding protein a (C/EBPa) inhibits cell proliferation through the p21(WAF-1/CIP-1/SDI-1) protein. Genes Dev 1996, 10:804-815. Gorospe M, Wang X, Holbrook NJ: p53-dependent elevation of p21Waf1 expression by UV light is mediated through mRNA stabilization and involves a vanadate-sensitive regulatory system. Mol Cell Biol 1998, 18:1400-1407. Joseph B, Orlian M, Furneaux H: p21Waf1 mRNA contains a conserved element in its 3′-untranslated region that is bound by the Elav-like mRNA-stabilizing ptoteins. J Biol Chem 1998, 273:20511-20516. Schwaller J, Koeffler HP, Niklaus G, Loetscher P, Nagel S, Fey MF, Tobler A: Posttranscriptional stabilization underlies p53-independent induction of p21WAF-1/CIP-1/SDI-1 in differentiating human leukemic cells. J Clin Investig 1995, 95:973-979. 8. 9. 7. Wang W, Furneaux H, Cheng H, Caldwell MC, Hutter D, Liu Y, Holbrook N, Gorospe M: HuR regulates p21 mRNA stabilization by UV light. Mol Cell Biol 2000, 20:760-769. Hsu CKA, Rishi AK, Li X-S, Gerald TM, Dawson MI, Schiffer C, Reichert U, Shroot B, Poirer GC, Fontana JA: Retinoid induced apoptosis in leukemia cells through a retinoic acid nuclear receptor-independent pathway. Blood 1997, 89(12):4470-79. Liang J-Y, Fontana JA, Rao JN, Ordonez JV, Dawson MI, Shroot B, Wilber JF, Feng P: A synthetic retinoid CD437 induces S-phase arrest and apoptosis in the human prostate cancer cells: LNCaP and PC-3. Prostate 1999, 38:228-236. Shao Z-M, Dawson MI, Li X-S, Rishi AK, Sheikh MS, Han Q-X, Ordonez JV, Shroot B, Fontana JA: p53-independent G0/G1 arrest and apoptosis induced by a novel retinoid in human breast cancer cells. Oncogene 1995, 11:493-504. 10. 11. Zhang Y, Rishi AK, Dawson MI, Tschang R, Farhana L, Boyanapalli M, Reichert U, Shroot B, Van Buren EC, Fontana JA: S phase arrest and apoptosis induced in normal mammary epithelial cells by a novel retinoid. Cancer Res 2000, 60:2025-2032. 12. Rishi AK, Sun R-J, Gao Y, Hsu CKA, Gerald TM, Sheikh MS, Dawson MI, Reichert U, Shroot B, Fornace AJ, Brewer G Jr, Fontana JA: Post- Transcriptional Regulation of the DNA damage - inducible gadd45 gene in human breast carcinoma cells exposed to a novel retinoid. Nucleic Acids Research 1999, 27:3111-3119. Li X-S, Rishi AK, Shao Z-M, Dawson MI, Jong L, Shroot B, Reichert U, Ordonez J, Fontana JA: Posttranscriptional regulation of p21WAF1/CIP1 expression in human breast carcinoma cells. Cancer Res 1996, 56:5055-5062. 13. 14. Papathanasiou MA, Kerr N, Robbins JH, McBride OW, Alamo I, Barrett SF Jr, Hickson I, Fornace AJ Jr: Induction by ionizing radiation of the gadd45 gene in cultured human cells: Lack of mediation by protein kinase C. Mol Cell Biol 1991, 11:1009-1016. 15. Ross J: mRNA stability in mammalian cells. Microbiological Reviews 1995, 59(3):423-450. 16. Malter JS, Hong YA: Redox switch and phosphorylation are involved in the posttranslational up-regulation of the adenosine-uridine binding factor by phorbol ester and ionophore. J Biol Chem 1991, 266:3167-3171. 17. You Y, Chen C-Y. A, Shyu A-B: U-rich sequence binding proteins (URBPs) interacting with a 20-nucleotide U-rich sequence in the 3′ untranslated region of c-fos mRNA may be involved in the first step of c-fos mRNA degradation. Mol Cell Biol 1992, 12:2931-2940. Laborda J: 36B4 cDNA used as an estradiol-independent mRNA control is the cDNA for human acidic ribosomal phosphoprotein PO. Nucleic Acids Res 19:3998. 18. 19. Rishi AK, Joyce-Brady M, Fisher J, Dobbs LG, Floros J, VanderSpek J, Brody JS, Williams MC: Cloning characterization, and developmental expression of a rat alveolar type I cell gene in embryonic endodermal and neuronal derivatives. Developmental Biology 1995, 167:294-306.