Targeting cellular FLICE-like inhibitory protein as a novel approach to the treatment of Hodgkin's lymphoma

Expert Review of Anticancer Therapy

Volumn 6, Issue 6, 2006, Pages 911-919

  Dutton, Amanda ^a   Burns, Alan T H ^b   Young, Lawrence S ^a   Murray, Paul G ^a  

^a UNIVERSITY OF BIRMINGHAM   (United Kingdom)

^b UNIVERSITY OF WOLVERHAMPTON   (United Kingdom)

Author keywords

Apoptosis; c FLIP; CD30; Gene therapy; Hodgkin's lymphoma; RNA interference; siRNA

Indexed keywords

ANTINEOPLASTIC AGENT; ANTISENSE OLIGONUCLEOTIDE; ATELOCOLLAGEN; B LYMPHOCYTE RECEPTOR; CD30 ANTIGEN; CD40 ANTIGEN; CELL PROTEIN; DRUG CARRIER; FAS ANTIGEN; FAS LIGAND; FLICE INHIBITORY PROTEIN; IMMUNOGLOBULIN ENHANCER BINDING PROTEIN; LIPID; LIPOSOME; MICRORNA; MONOCLONAL ANTIBODY; OLIGONUCLEOTIDE; POLYMER; RIBOZYME; SHORT HAIRPIN RNA; SMALL INTERFERING RNA; TUMOR NECROSIS FACTOR RELATED APOPTOSIS INDUCING LIGAND; VASCULOTROPIN RECEPTOR 2; CFLAR PROTEIN, HUMAN; SIGNAL PEPTIDE; TUMOR NECROSIS FACTOR RECEPTOR;

CANCER COMBINATION CHEMOTHERAPY; CANCER MORTALITY; CANCER RELAPSE; CANCER SURVIVAL; CANCER THERAPY; CELL DEATH; GENE THERAPY; GERM CELL; HODGKIN DISEASE; HUMAN; NONHUMAN; PATHOGENESIS; PROTEIN EXPRESSION; PROTEIN TARGETING; REED STERNBERG CELL; REVIEW; APOPTOSIS; BIOSYNTHESIS; DOWN REGULATION; GENETICS; PATHOPHYSIOLOGY; PHYSIOLOGY; RNA INTERFERENCE;

ANTIGENS, CD30; ANTIGENS, CD95; ANTINEOPLASTIC AGENTS; APOPTOSIS; CASP8 AND FADD-LIKE APOPTOSIS REGULATING PROTEIN; DOWN-REGULATION; GENE THERAPY; HODGKIN DISEASE; HUMANS; INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS; RECEPTORS, TUMOR NECROSIS FACTOR; RNA INTERFERENCE; RNA, SMALL INTERFERING;

EID: 33745149018     PISSN: 14737140     EISSN: 17448328     Source Type: Journal    
DOI: 10.1586/14737140.6.6.911     Document Type: Review

References (109)

1. Harris NL, Jaffe ES, Stein H et al. A revised European-American classification of lymphoid neoplasms: a proposal from the International Lymphoma Study Group. Blood 84, 1361-1392 (1994).
2. Yung L, Linch D. Hodgkin's lymphoma. Lancet 361, 943-951 (2003).
3. Ng AK, Bernardo MP, Weller E et al. Long-term survival and competing causes of death in patients with early-stage Hodgkin's disease treated and 50 or younger. J. Clin. Oncol. 20, 2101-2102 (2002).
4. Swerdlow AJ, Schoemaker MJ, Allerton R et al. Lung cancer after Hodgkin's disease: a nested case-control study of the relation to treatment. J. Clin. Oncol. 19, 1610-1618 (2001).
5. Hancock SL, Tucker MA, Hoppe RT. Factors affecting late mortality from heart disease after treatment of Hodgkin's disease. JAMA 270, 1949-1955 (1993).
6. Whitehead E, Shalet SM, Blacklegde G. The effects of Hodgkin's disease and combination chemotherapy on gonadal function in the adult male. Cancer 49, 418-422 (1982).
7. Whitehead E, Shalet SM, Blackledge G et al. The effect of combination chemotherapy on ovarian function in women treated for Hodgkin's disease. Cancer 52, 988-992 (1983).
8. Friedmann AM, Hudson MM, Weinstein HJ et al. Treatment of unfavourable childhood Hodgkin's disease with VEPA and low dose, involved-field radiation. J. Clin. Oncol. 20, 3088-3094 (2002).
9. Donaldson, SS. Pediatric Hodgkin's disease-up, up, and beyond. Int. J. Radiat. Oncol. Biol. Phys. 54, 1-8 (2002).
10. Kuppers R, Rajewsky K. The origin of Hodgkin and Reed/Sternberg cells in Hodgkin's disease. Annu. Rev. Immunol. 16, 471-493 (1998).
11. MacLennan ICM. Germinal centres. Annu. Rev. Immunol. 12, 117-1139 (1994).
12. Liu YL, Grouard G, de Bouteiller O, Banchereau J. Follicular dendritic cells and germinal centres. Int. Rev. Cytol. 166, 139-179 (1996).
13. Holder MJ Wang H, Milner AE et al. Suppression of apoptosis in normal and neoplastic human B lymphocytes by CD40 ligand is independent of Bcl-2 induction. Eur. J. Immunol. 23, 2368-2371 (1993).
14. Gordon J. CD40 and its ligand: central players in B lymphocyte survival, growth and differentiation. Blood Rev. 9, 53-56 (1995)
15. Kehry MR. CD40-mediated signalling in B cells. Balancing cell survival, growth and death. J. Immunol. 56, 345-348 (1996).
16. Pound JD, Gordon J. Maintenance of human germinal centre B cells in vitro. Blood 89, 919-928 (1997).
17. Nagata S, Golstein P. The Fas death factor. Science 267, 1449-1456 (1995).
18. Cleary AM, Fortune SM, Yellin MJ, Chess L, Lederman S. Opposing roles of CD95 (Fas/APO-1) and CD40 in death and rescue of human low density tonsillar B cells. J. Immunol. 155, 3329-3337 (1995).
19. Takahashi Y, Ohta H, Takemori T. Fas is required for clonal selection in germinal centres and the subsequent establishment of the memory B cell repertoire. Immunity 14, 181-192 (2001).
20. Martinez-Valdez H, Guret C, de Bouteiller O, Fugier I Banchereau J, Liu YJ. Human germinal centre B cells express the apoptosis inducing genes fas, c-myc, p53 and Bax but not the survival gene bcl-2. J. Exp. Med. 183, 971-977 (1996).
21. van Eijk M, Defrance T, Hennino A, de Groot C. Death-receptor contribution to the germinal-centre reaction. Trends Immunol. 22, 677-682 (2001).
22. Marafioti T, Hummel M, Anagnostopoulos I et al. Origin of nodular lymphocyte-pedominant Hodgkin's disease from a clonal expansion of highly mutated germinal-centre B cells. N. Engl. J. Med. 337, 453-458 (1997).
23. Marafioti T, Hummel M, Foss HD et al. Hodgkin and Reed-Sternberg cells represent an expansion of a single clone originating from a germinal centre B cell with functional immunoglobulin gene rearrangements but defective immunoglobulin transcription. Blood 95, 1443-1450 (2000).
24. Braeuninger A, Kuppers R, Strickler JG, Wacker HH, Rajewsky K, Hansmann ML. Hodgkin and Reed-Sternberg cells in lymphocyte predominance Hodgkin's disease represent clonal populations of germinal centre-derived tumor cells. Proc. Natl Acad. Sci. USA 94, 9337-9342 (1997).
25. Kanzler H, Kuppers R, Hansmann ML, Rajewsky K. Hodgkin and Reed/ Sternberg cells in Hodgkin's disease represent the outgrowth of a dominant tumor clone derived from (crippled) germinal centre B cells. J. Exp. Med. 184, 1495-1505 (1996).
26. Kuppers R, Rajewsky K, Zhao M et al. Hodgkin's disease: Hodgkin and Reed/ Sternberg cells picked from histological sections show clonal immnologlobulin gene rearrangements and appear to be derived from B cells at various stages of development. Proc. Natl Acad. Sci. USA 91, 962-966 (1994).
27. Re D, Hofmann A, Wolf J, Diehl V, Staratschek-Jox A. Cultivated H-RS cells are resistant to CD95L-mediated apoptosis despite expression of wild-type CD95. Exp. Hematol. 28, 31-35 (2000).
28. Stein H, Marafioti T, Foss HD et al. Down-regulation of BOB.1/OBF.1 and Oct2 in classical Hodgkin's disease correlates with immunoglobulin transcription. Blood 97, 496-501 (2001).
29. Doerr JR, Malone CS, Fike FM et al. Patterned CpG methylation of silenced B cell gene promoters in classical Hodgkin lymphoma-derived and primary effusion lymphoma cell lines. J. Mol. Biol. 22, 631-640 (2005).
30. Ushmorov A, Leithauser FR, Sakk O et al. Epigenetic processes play a major role in B cell-specific gene silencing in classical Hodgkin lymphoma. Blood 107, 2493-2500 (2005).
31. Itoh N, Yonehara S, Ishii A et al. The polypeptide encoded by the cDNA for human cell surface antigen Fas can mediate apoptosis. Cell. 66, 233-243 (1991).
32. Chinnaiyan AM, Tepper CG, Seldin MF et al. FADD/MORT1 is a common mediator of CD95 (Fas/APO-1) and tumour necrosis factor receptor-induced apoptosis. J. Biol. Chem. 271, 4961-4965 (1996).
33. Kischkel FC, Hellbardt S, Behrmann I et al. Cytotoxicity-dependent APO-1 (Fas/CD95)-associated proteins form a death-inducing signalling complex (DISC) with the receptor. EMBO J. 14, 5579-5588 (1995).
34. Kischkel FC, Lawrence DA, Tinel A et al. Death receptor recruitment of endogenous caspase-10 and apoptosis initiation in the absence of caspase-8. J. Biol. Chem. 276, 46639-46646 (2001).
35. Shi Y. Caspase activation: revisiting the induced proximity model. Cell 117, 855-858 (2004).
36. Boatright KM, Renatus M, Scott FL et al. A unique model for apical caspase activation. Mol. Cell. 11, 529-541 (2003).
37. Donepudi M, Mac Sweeney A, Briand C, Grutter MG. Insights into the regulatory mechanism for caspase-8 activation. Mol. Cell. 11, 543-549 (2003).
38. Smyth MJ, Takede K, Hayakawa Y et al. Nature's TRAIL - on a path to cancer immunotherapy. Immunity 18, 1-6 (2003).
39. Sprick MR, Weigand MA, Reiser E et al. FADD/MORT1 and caspase-8 are recruited to TRAIL receptors 1 and 2 and are essential for apoptosis mediated by TRAIL receptor 2. Immunity 12, 599-609 (2000).
40. Kischkel FC, Lawrence DA, Chuntharapai A, Schow P, Kim KJ, Ashkenazi A. Apo2L/TRAIL-dependent recruitment of endogenous FADD and caspase 8 to death receptors 4 and 5. Immunity 12, 611-620 (2000).
41. Kelley SK, Ashkenazi A. Targeting death receptors in cancer with Apo2L/ TRAIL. Curr. Opin. Pharmacol. 4, 333-339 (2004).
42. Bouralexis S, Findlay DM, Evdokiou A. Death to the bad guys: targeting cancer via Apo2L/TRAIL. Apoptosis 10, 35-51 (2005).
43. Fandy TE, Srivastava RK. Trichostatin A sensitises TRAIL-resistant myeloma cells by downregulation of the antiapoptotic Bcl-2 proteins. Cancer Chemother: Pharmacol. DOI 10.1007/s00280-005-0184-3 (2006) (Epub ahead of print).
44. O'Kane HF, Watson CJ, Johnston SR, Petak I, Watson RW, Williamson KE. Targeting death receptors in bladder, prostate and renal cancer. J. Urol. 175, 432-438 (2006).
45. Kunhong K, Fisher MJ, Xu SQ, El-Deiry WS. Molecular determinant of response to TRAIL in killing of normal and cancer cells. Clin. Cancer Res. 6, 335-346 (2000).
46. Liu X, Yue P, Khuri FR, Sun SY. Decoy receptor 2 (DcR2) is a p53 target gene and regulates chemosensitivity. Cancer Res. 65, 9169-9175 (2005).
47. Thome M, Schneider P, Hofmann K et al. Viral FLICE-inhibitory protein (FLIPs) prevents apoptosis induced by death receptors. Nature 386, 517-521 (1997).
48. Irmler M, Thome M, Hahne M et al. Inhibition of death receptor signals by cellular FLIP. Nature 388, 190-195 (1997).
49. Shu HB, Halpin DR, Goeddel DV. Casper is a FADD- and caspase-related inducer of apoptosis. Immunity 6, 751-763 (1997).
50. Hu S, Vincenz C, Ni J, Gentz R, Dixit VM. I-FLICE, a novel inhibitor of tumour necrosis factor-1 and CD-95-induced apoptosis. J. Biol. Chem. 273, 17255-17257 (1997).
51. Srinivasula SM, Ahmad M, Ottilies S et al. FLAME-1, a novel FADD-like anti-apoptotic molecule that regulates Fas/TNFR1-induced apoptosis. J. Biol. Chem. 272, 18542-18545 (1997).
52. Goltsev YV, Kovalenko AV, Arnold E et al. CASH, a novel caspase homologue with death effector domains. J. Biol. Chem. 272, 19641-19644 (1997).
53. Inohara N, Koseki T, Hu Y, Chen S, Nunez G. CLARE, a death effector domain-containing protein interacts with caspase-8 and regulates apoptosis. Proc. Natl Acad. Sci. USA 94, 10717-10722 (1997).
54. Han DK, Chaudhary PM, Wright ME et al. MRIT, a novel death-effector domain-containing protein, interacts with caspases and BclXL and initiates cell death. Proc. Natl Acad. Sci. USA 94, 11333-11338 (1997).
55. Rasper DM, Vaillancourt JP, Hadano S et al. Cell death attenuation by 'Usurpin', a mammalian DED-caspase homologue that precludes caspase-8 recruitment and activation by CD-95 (Fas, APO-1) receptor complex. Cell Death Differ. 5, 271-288 (1998).
56. Mathas S, Lietz A, Anagnostopoulos et al. c-FLIP mediates resistance of Hodgkin/Reed-Sternberg cells to death receptor-induced apoptosis. J. Exp. Med. 199, 1041-1052 (2004).
57. Golks A, Brenner D, Fritsh C, Krammer PH, Lavrik IN. c-FLIPR, a new regulator death receptor-induced apoptosis. J. Biol. Chem. 280, 14507-14513 (2005).
58. Scaffidi C, Schmitz I, Krammer PH, Peter ME. The role of c-FLIP in modulation of CD95-induced apoptosis. J. Biol. Chem. 274, 1541-1548 (1999).
59. Krueger A, Schmitz I, Baumann S, Krammer PH, Kirchhoff S. Cellular FLICE-inhibitory protein splice variants inhibit different steps of caspase 8 activation at the CD95 death induced signalling complex. J. Biol. Chem. 276, 20633-20640 (2001).
60. Micheau O, Thome M, Schneider P et al. The long form of FLIP is an activator of caspase-8 at the Fas death-inducing signalling complex. J. Biol. Chem. 277, 45162-45171 (2002).
61. Boatright KM, Deis C, Denault DP, Salvesen GS. Activation of caspases-8 and-10 by FLIPL. Biochem. J. 382, 651-657 (2004).
62. L is a dual function regulator for caspase-8 activation and CD95-mediated apoptosis. EMBO J. 21, 3704-3714 (2002).
63. Xerri L, Carbuccia N, Parc P, Hassoun J, Birg F. Frequent expression of Fas/APO-1 in Hodgkins disease and anaplastic large cell lymphomas. Histopathology 27, 235-241 (1995).
64. Metkar SS, Naresh KN, Redkar AA, Soman CS, Advani SH, Nadkarni JJ. Expression of Fas and Fas ligand in Hodgkin's disease. Leuk. Lymphoma 33, 521-530 (1999).
65. Dutton A, O'Neil JD, Milner AE et al. Expression of the cellular FLICE-inhibitory protein (c-FLIP) protects Hodgkin's lymphoma cells from autonomous Fas-mediated death. Proc. Natl. Acad. Sci. USA 101, 6611-6616 (2004).
66. Thomas RK, Kallenborn A, Wickenhauser C. Constitutive expression of c-FLIP in Hodgkin and Reed-Sternberg cells. Am. J. Pathol. 160, 1521-1528 (2002).
67. Muschen M, Re D, Brauniger A et al. Somatic mutations of the CD95 gene in Hodgkin and Reed-Sternberg cells. Cancer Res. 60, 5640-5643 (2000).
68. Maggio EM, van den Berg A, de Jong D, Diepstra A, Poppema S. Low frequency of Fas mutations I Reed-Sternberg cells of Hodgkin's lymphoma. Am. J. Pathol. 162, 29-35 (2003).
69. Micheau O, Lens S, Goude O, Alevizopoulas K, Tschopp J. NF-κB signals induce the expression of c-FLIP. Mol. Cell. Biol. 21, 5299-5305 (2001).
70. Suhara T, Mano T, Oliveira B, Walsh K. Phosphatidylinositol 3-kinase/Akt signaling controls endothelial cell sensitivity to Fas-mediated apoptosis via regulation of FLICE-inhibitory protein (FLIP). Circ. Res. 89, 13-19 (2001).
71. Yeh JH, Hsu SC, Han SH, Lai MZ. Mitogen-activated protein kinase kinase antagonized fas-associated death domain protein-mediated apoptosis by induced FLICE-inhibitory protein expression. J. Exp. Med. 188, 1795-802 (1998).
72. Hu W, Johnson H, Shu HB. Activation of NF-κB by FADD, casper, and caspase-8. J. Biol. Chem. 275, 10838-10844 (2000).
73. Kataoka T, Budd RC, Holler N et al. The caspase-8 inhibitor FLIP promotes activation of NF-κB and Erk signaling pathways. Curr. Biol. 10, 640-648 (2000).
74. Chaudhary PM, Eby MT, Jasmin A, Kumar A, Liu L, Hood L. Activation of the NF-κB pathway by caspase 8 and its homologs. Oncogene 19, 4451-4460 (2000).
75. L processed by caspase 8 specifically interacts with TRAF2 and induces activation of the NF-κB signaling pathway. Mol. Cell. Biol. 24, 2627-2636 (2004).
76. Kreuz S, Siegmund D, Rumpf JJ et al. NfκB activation by Fas is mediated through FADD, caspase-8, and RIP and is inhibited by FLIP. J. Cell. Biol. 166, 369-380 (2004).
77. Watcher T, Sricks M, Hausmann D et al. cFLIPL inhibits tumour necrosis factor-related apoptosis-inducing ligand-mediated NF-κB activation at the death signaling complex in human keratinocytes. J. Biol. Chem. 51, 52824-52834 (2004).
78. Zhang N, He YW. An essential role for c-FLIP in the efficient development of T lymphocytes. J. Exp. Med. 202, 395-404 (2005).
79. Emmerich F, Meiser M, Hummel M et al. Overexpression of IBα without inhibition of NFκB activity and mutations in the IBα gene in Reed-Sternberg cells. Blood 94, 3129-3134 (1999).
80. Cabannes E, Khan G, Aillet F, Jarrett RF, Hay RT. Mutations in the IBα gene in Hodgkins disease suggest a tumour suppressor role for IBα. Oncogene 18, 3063-3070 (1999).
81. Jungnickel B, Staratschek-Jox A, Brauninger A et al. Clonal deleterious mutations in the IBα gene in the malignant cells in Hodgkin's lymphoma. J. Exp. Med. 191, 395-402 (2002).
82. Krappmann D, Emmerich F, Kordes U, Scharschmidt E, Dorken B, Scheidereit C. Molecular mechanisms of constitutive NF-B/Rel activation in Hodgkin/ Reed-Sternberg cells. Oncogene 18, 943-953 (1999).
83. Takei Y, Kadomatsu K, Yuzawa Y et al. Small interfering RNA targeting vascular endothelial growth factor as cancer therapeutics. Cancer Res. 64, 3365-3370 (2004).
84. Morrissey DV, Lockridge JA, Shaw L et al. Potent and persistent in vivo anti-HBV activity of chemically modified siRNAs. Nat. Biotechnol. 23, 1002-1007 (2005).
85. Schiffelers RM, Ansari A, Xu J et al. Cancer siRNA therapy by tumor selective delivery with ligand-targeted sterically stabilized nanoparticle. Nucleic Acids Res. 32, e149 (2004).
86. Song E, Zhu P, Lee SK et al. Antibody mediated in vivo delivery of small interfering RNAs via cell-surface receptors. Nat. Biotech. 23, 709-717 (2005).
87. Karagiannis TC, El-Osta A. RNA interference and potential therapeutic applications of short interfering RNAs. Cancer Gene. Ther. 12, 787-795 (2005).
88. Durkop H, Latza U, Hummel M, Eitelbach F, Seed B, Stein H. Molecular cloning and expression of a new member of the nerve growth factor receptor family that is characteristic for Hodgkin's disease. Cell 68, 421-427 (1992).
89. Schwab U, Stein H, Gerdes J et al. Production of a monoclonal antibody specific for Hodgkin and Sternberg-Reed cells of Hodgkin's disease and a subset of normal lymphoid cells. Nature 299, 65-67 (1982).
90. Higuchi M, Matsuda T, Mori N et al. Elevated expression of CD30 in adult T-cell leukemia cell lines: possible role in constitutive NF-κB activation. Retrovirilogy 2, 29-40 (2005).
91. + T cells. J. Immunol. 151, 2380-2389 (1993).
92. Pallesen G, Hamilton-Dutoit SJ. Ki-1 (CD30) antigen is regularly expressed by tumor cells of embryonal carcinoma. Am. J Pathol. 133, 446-450 (1998).
93. Hittmair A, Rogatsch H, Hobisch A, Mikuz G, Feichtinger H. CD30 expression in seminoma. Hum. Pathol. 27, 1166-1171 (1996).
94. Andreesen R, Brugger W, Lohr GW, Bross KJ. Human macrophages can express the Hodgkin's cell-associated antigen Ki-1 (CD30). Am. J. Pathol. 134, 187-192 (1989).
95. Sohail D, Simpson RH. Ber-H2 staining of lipoblasts. Histopathology 18, 191 (1991).
96. Ito K, Watanabe T, Horie R, Shiota M, Kawamura S, Mori S. High expression of the CD30 molecule in human decidual cells. Am. J Pathol. 145, 276-280 (1994).
97. Papadopoulos N, Galazios G, Anastasiadis P et al. Human decidual cells can express the Hodgkins cell-associated antigen Ki-1(CD30) in spontaneous abortions during the first trimester of gestation. Clin. Exp. Obstet. Gynecol. 28, 225-228 (2001).
98. Mechtersheimer G, Moller P. Expression of Ki-1 antigen (CD30) in mesenchymal tumors. Cancer 66, 1732-1737 (1990).
99. Tamiolakis D, Papadopoulos N, Lambropoulou M et al. Ber-H2 (CD30) immunohistochemical staining of human fetal tissues. Int. J. Biol. Sci. 1, 135-140 (2005).
100. Davidson SM, Stephanou A, Latchman DS. FLIP protects cardiomyocytes from apoptosis induced by stimulated ischemia/reoxygenation, as demonstrated by short hairpin (shRNA) silencing of FLIP mRNA. J. Mol. Cell. Cardiol. 35, 1359-1364 (2003).
101. Ashany D, Savir A, Bhardwaj N, Elkon KB. Dendritic cells are resistant to apoptosis through the Fas (CD95/APO-1) pathway. J. Immunol. 163, 5303-5311 (1999).
102. Bouchet D, Tesson L, Meboret S et al. Differential sensitivity of endothelial cells of various species to apoptosis induced by gene transfer of Fas ligand: role of FLIP levels. Mol. Med. 8, 612-623 (2002).
103. Budd RC, Yeh WC, Tschopp J. cFLIP regulation of lymphocyte activation and development. Nat. Rev. Immunol. 6, 196-204 (2006)
104. Hennino A, Berard M, Casamayor-Palleja M, Krammer PH, Defrance T. Regulation of the Fas death pathway by FLICE-inhibitory protein in primary human B cells. J. Immunol. 165, 3023-3030 (2000).
105. Hennino A, Berard M, Krammer PH, Defrance T. FLICE-inhibitory protein is a key regulator of germinal center B cell apoptosis. J. Exp. Med. 193, 447-458 (2001).
106. Durkop H, Oberbarnscheidt M, Latza U et al. The restricted expression pattern of the Hodgkin's lymphoma-associated cytokine receptor CD30 is regulated by a minimal promoter. J. Pathol. 192, 182-193 (2000).
107. + cells. Biochim. Biophys. Acta 163, 633-641 (2001).
108. Cullen BR. RNAi the natural way. Nat. Genet. 37, 1163-1165 (2005).
109. Dickins RA, Hemann MT, Zilfou JT et al. Probing tumor phenotypes using stable and regulated synthetic microRNA precursors. Nat. Genet. 37, 1289-1295 (2005).