CEBPD 為 CCAAT/Enhancer binding protein (C/EBP) 家族成員之
一。已知 CEBPD 在細胞分化，發炎機制及脂質生合成有重要的功能扮演。近年來的一些文獻報導以及實驗室先前的研究顯示 CEBPD 可以誘發細胞的生長停滯並且促進細胞的分化，並且在調控 pro-apoptotic 基因的表現上扮演重要的角色， 是為相當有潛力抑癌基因。已知retinoblastoma protein (Rb) 在細胞週期中扮演一重要角色，目前對於其與E2F1 作用在 G1/S 轉換點的研究最為人熟知。在本論文中，我們發現甘草萃取物其衍生物hydroxydibenzoylmethane （HMDB） 能夠促進CEBPD 在細胞中的轉錄活化作用，同時也活化 PPARG2 和 GADD153基因的表現。此外，我們也證實了 CEBPD 在活體中能與 Rb 有交互作用的關係，並且 Rb 對於 CEBPD 所活化的基因轉錄作用有一負向的調控機制。再者，大量產生的 CEBPD 可對 Rb/E2F1 複合體產生拮抗作用，轉而活化 Rb/E2F1 複合體所抑制的下游基因。

The CCAAT/enhancer-binding protein (CEBP) family of transcription factors plays an important role in controlling cell proliferation and differentiation. CEPBD, one of the CEBP family members, has been reported
to be a potential tumor suppressor because it can induce growth arrest to involve in differentiation and play as a crucial regulator of pro-apoptotic gene expression. Retinoblastoma protein（Rb）is well known to be an important regulator in the G1/S transition or differentiation through the interaction with E2F1. In this study, we found that a DBM structure-related compound -
hydroxymethyldibenzoylmethane (HMDB) can induce CEBPD, PPARG2 and GADD153 transcription. We also demonstrated that Rb physically interacts with CEBPD and plays a negative role in the CEBPD-mediated PPARG2 and
GADD153 transcription. Furthermore, our data suggest that CEBPD can activate the apoptotic gene through the de-repression of Rb/E2F1-mediated gene inactivation.

參考文獻
1. Gu, J., Tamura, M. and Yamada, K.M. (1998) Tumor suppressor
PTEN inhibits integrin- and growth factor-mediated
mitogen-activated protein (MAP) kinase signaling pathways. J Cell
Biol, 143, 1375-1383.
2. Chen, P.L., Riley, D.J., Chen, Y. and Lee, W.H. (1996)
Retinoblastoma protein positively regulates terminal adipocyte
differentiation through direct interaction with C/EBPs. Genes Dev,
10, 2794-2804.
3. Johnson, P.F. (2005) Molecular stop signs: regulation of cell-cycle
arrest by C/EBP transcription factors. J Cell Sci, 118, 2545-2555.
4. Sherr, C.J. (2004) Principles of tumor suppression. Cell, 116,
235-246.
5. Du, W. and Pogoriler, J. (2006) Retinoblastoma family genes.
Oncogene, 25, 5190-5200.
6. Kelloff, G.J., Boone, C.W., Crowell, J.A., Steele, V.E., Lubet, R.
and Sigman, C.C. (1994) Chemopreventive drug development:
perspectives and progress. Cancer Epidemiol Biomarkers Prev, 3,
44
85-98.
7. Sharma, S., Stutzman, J.D., Kelloff, G.J. and Steele, V.E. (1994)
Screening of potential chemopreventive agents using biochemical
markers of carcinogenesis. Cancer Res, 54, 5848-5855.
8. Caracciolo, V., Reiss, K., Khalili, K., De Falco, G.and Giordano, A.
(2006) Role of the interaction between large T antigen and Rb
family members in the oncogenicity of JC virus. Oncogene, 25,
5294-5301.
9. Pan, M.H., Ghai,G. and Ho, C.T. (2008) Food bioactives, apoptosis,
and cancer. Mol Nutr Food Res, 52, 43-52.
10. Plummer, S.M., Holloway, K.A., Manson, M.M., Munks, R.J.,
Kaptein, A., Farrow, S. and Howells, L. (1999) Inhibition of
cyclo-oxygenase 2 expression in colon cells by the
chemopreventive agent curcumin involves inhibition of NF-kappaB
activation via the NIK/IKK signalling complex. Oncogene, 18,
6013-6020.
11. Huang, M.T., Lou, Y.R., Xie, J.G., Ma, W., Lu, Y.P., Yen, P., Zhu,
B.T., Newmark, H. and Ho, C.T. (1998) Effect of dietary curcumin
45
and dibenzoylmethane on formation of
7,12-dimethylbenz[a]anthracene-induced mammary tumors and
lymphomas/leukemias in Sencar mice. Carcinogenesis, 19,
1697-1700.
12. Singletary, K. and MacDonald, C. (2000) Inhibition of
benzo[a]pyrene- and 1,6-dinitropyrene-DNA adduct formation in
human mammary epithelial cells bydibenzoylmethane and
sulforaphane. Cancer Lett, 155, 47-54.
13. Pan, M.H., Sin, Y.H., Lai, C.S., Wang, Y.J., Lin, J.K., Wang, M.
and Ho, C.T. (2005) Induction of apoptosis by
1-(2-hydroxy-5-methylphenyl)-3-phenyl-1,3-propanedione through
reactive oxygen species production, GADD153 expression, and
caspases activation in human epidermoid carcinoma cells. J Agric
Food Chem, 53, 9039-9049.
14. Ramji, D.P. and Foka, P. (2002) CCAAT/enhancer-binding proteins
: structure, function and regulation. Biochem J, 365, 561-575.
15. Kinoshita, S., Akira, S. and Kishimoto, T. (1992) A member of the
C/EBP family, NF-IL6 beta, forms a heterodimer and
transcriptionally synergizes with NF-IL6. Proc Natl Acad Sci U S A,
46
89, 1473-1476.
16. Tengku-Muhammad, T.S., Hughes, T.R., Ranki, H., Cryer, A. and
Ramji, D.P. (2000) Differential regulation of macrophage
CCAAT-enhancer binding protein isoforms by lipopolysaccharide
and cytokines. Cytokine, 12, 1430-1436.
17. Cardinaux, J.R., Allaman, I. and Magistretti, P.J. (2000)
Pro-inflammatory cytokines induce the transcription factors
C/EBPbeta and C/EBPdelta in astrocytes. Glia, 29, 91-97.
18. Clarkson, R.W., Chen, C.M., Harrison, S., Wells, C., Muscat, G.E.
and Waters, M.J. (1995) Early responses of trans-activating factors
to growth hormone in preadipocytes: differential regulation of
CCAAT enhancer-binding protein-beta (C/EBP beta) and C/EBP
delta. Mol Endocrinol, 9, 108-120.
19. Cao, Z., Umek, R.M. and McKnight, S.L. (1991) Regulated
expression of three C/EBP isoforms during adipose conversion of
3T3-L1 cells. Genes Dev, 5, 1538-1552.
20. Scott, L.M., Civin, C.I., Rorth, P. and Friedman, A.D. (1992) A
novel temporal expression pattern of three C/EBP family members
47
in differentiating myelomonocytic cells. Blood, 80, 1725-1735.
21. Ikezoe, T., Gery, S., Yin, D., O'Kelly, J., Binderup, L., Lemp, N.,
Taguchi, H. and Koeffler, H.P. (2005) CCAAT/enhancer-binding
protein delta: a molecular target of 1,25-dihydroxyvitamin D3 in
androgen-responsive prostate cancer LNCaP cells. Cancer Res, 65,
4762-4768.
22. Gery, S., Tanosaki, S., Hofmann, W.K., Koppel, A. and Koeffler,
H.P. (2005) C/EBPdelta expression in a BCR-ABL-positive cell
line induces growth arrest and myeloid differentiation. Oncogene,
24, 1589-1597.
23. Thangaraju, M., Rudelius, M., Bierie, B., Raffeld, M., Sharan, S.,
Hennighausen, L., Huang, A.M. and Sterneck, E. (2005)
C/EBPdelta is a crucial regulator of pro-apoptotic gene expression
during mammary gland involution. Development, 132, 4675-4685.
24. Ron, D. and Habener, J.F. (1992) CHOP, a novel developmentally
regulated nuclear protein that dimerizes with transcription factors
C/EBP and LAP and functions as a dominant-negative inhibitor of
gene transcription. Genes Dev, 6, 439-453.
25. Fornace, A.J., Jr., Alamo, I., Jr. and Hollander, M.C. (1988) DNA
48
damage-inducible transcripts in mammalian cells. Proc Natl Acad
Sci U S A, 85, 8800-8804.
26. Sylvester, S.L., ap Rhys, C.M., Luethy-Martindale, J.D. and
Holbrook, N.J. (1994) Induction of GADD153, a
CCAAT/enhancer-binding protein (C/EBP)-related gene, during the
acute phase response in rats. Evidence for the involvement of
C/EBPs in regulating its expression. J Biol Chem, 269,
20119-20125.
27. Guyton, K.Z., Xu, Q. and Holbrook, N.J. (1996) Induction of the
mammalian stress response gene GADD153 by oxidative stress:
role of AP-1 element. Biochem J, 314 ( Pt 2), 547-554.
28. Luethy, J.D., Fargnoli, J., Park, J.S., Fornace, A.J., Jr. and
Holbrook, N.J. (1990) Isolation and characterization of the hamster
gadd153 gene. Activation of promoter activity by agents that
damage DNA. J Biol Chem, 265, 16521-16526.
29. Halleck, M.M., Liu, H., North, J. and Stevens, J.L. (1997)
Reduction of trans-4,5-dihydroxy-1,2-dithiane by cellular
oxidoreductases activates gadd153/chop and grp78 transcription
and induces cellular tolerance in kidney epithelial cells. J Biol
49
Chem, 272, 21760-21766.
30. Oyadomari, S. and Mori, M. (2004) Roles of CHOP/GADD153 in
endoplasmic reticulum stress. Cell Death Differ, 11, 381-389.
31. Matsumoto, M., Minami, M., Takeda, K., Sakao, Y. and Akira, S.
(1996) Ectopic expression of CHOP (GADD153) induces apoptosis
in M1 myeloblastic leukemia cells. FEBS Lett, 395, 143-147.
32. Ubeda, M., Wang, X.Z., Zinszner, H., Wu, I., Habener, J.F. and Ron
, D. (1996) Stress-induced binding of the transcriptional factor
CHOP to a novel DNA control element. Mol Cell Biol, 16,
1479-1489.
33. Classon, M. and Dyson, N. (2001) p107 and p130: versatile
proteins with interesting pockets. Exp Cell Res, 264, 135-147.
34. Muller, H., Moroni, M.C., Vigo, E., Petersen, B.O., Bartek, J. and
Helin, K. (1997) Induction of S-phase entry by E2F transcription
factors depends on their nuclear localization. Mol Cell Biol, 17,
5508-5520.
35. Verona, R., Moberg, K., Estes, S., Starz, M., Vernon, J.P. and Lees,
50
J.A. (1997) E2F activity is regulated by cell cycle-dependent
changes in subcellular localization. Mol Cell Biol, 17, 7268-7282.
36. Trimarchi, J.M. and Lees, J.A. (2002) Sibling rivalry in the E2F
family. Nat Rev Mol Cell Biol, 3, 11-20.
37. Aslanian, A., Iaquinta, P.J., Verona, R. and Lees, J.A. (2004)
Repression of the Arf tumor suppressor by E2F3 is required for
normal cell cycle kinetics. Genes Dev, 18, 1413-1422.
38. Rosen, E.D. and Spiegelman, B.M. (2001) PPARgamma : a nuclear
regulator of metabolism, differentiation, and cell growth. J Biol
Chem, 276, 37731-37734.
39. Werman, A., Hollenberg, A., Solanes, G., Bjorbaek, C., Vidal-Puig,
A.J. and Flier, J.S. (1997) Ligand-independent activation domain in
the N terminus of peroxisome proliferator-activated receptor
gamma (PPARgamma). Differential activity of PPARgamma1 and
-2 isoforms and influence of insulin. J Biol Chem, 272,
20230-20235.
40. Tontonoz, P., Hu, E. and Spiegelman, B.M. (1994) Stimulation of
adipogenesis in fibroblasts by PPAR gamma 2, a lipid-activated
51
transcription factor. Cell, 79, 1147-1156.
41. Vidal-Puig, A.J., Considine, R.V., Jimenez-Linan, M., Werman, A.,
Pories, W.J., Caro, J.F. and Flier, J.S. (1997) Peroxisome
proliferator-activated receptor gene expression in human tissues.
Effects of obesity, weight loss, and regulation by insulin and
glucocorticoids. J Clin Invest, 99, 2416-2422.
42. Sarraf, P., Mueller, E., Jones, D., King, F.J., DeAngelo, D.J.,
Partridge, J.B., Holden, S.A., Chen, L.B., Singer, S., Fletcher, C. et
al. (1998) Differentiation and reversal of malignant changes in
colon cancer through PPARgamma. Nat Med, 4, 1046-1052.
43. Mueller, E., Sarraf, P., Tontonoz, P., Evans, R.M., Martin, K.J.,
Zhang, M., Fletcher, C., Singer, S. and Spiegelman, B.M. (1998)
Terminal differentiation of human breast cancer through PPAR
gamma. Mol Cell, 1, 465-470.
44. Panigrahy, D., Singer, S., Shen, L.Q., Butterfield, C.E., Freedman,
D.A., Chen, E.J., Moses, M.A., Kilroy, S., Duensing, S., Fletcher,
C. et al. (2002) PPARgamma ligands inhibit primary tumor growth
and metastasis by inhibiting angiogenesis. J Clin Invest, 110,
923-932.
52
45. O'Rourke, J., Yuan, R. and DeWille, J. (1997)
CCAAT/enhancer-binding protein-delta (C/EBP-delta) is induced
in growth-arrested mouse mammary epithelial cells. J Biol Chem,
272, 6291-6296.
46. Huang, A.M., Montagna, C., Sharan, S., Ni, Y., Ried, T. and
Sterneck, E. (2004) Loss of CCAAT/enhancer binding protein delta
promotes chromosomal instability. Oncogene, 23, 1549-1557.
47. Sivko, G.S. and DeWille, J.W. (2004) CCAAT/Enhancer binding
protein delta (c/EBPdelta) regulation and expression in human
mammary epithelial cells: I. "Loss of function" alterations in the
c/EBPdelta growth inhibitory pathway in breast cancer cell lines. J
Cell Biochem, 93, 830-843.
48. Tang, D., Sivko, G.S. and DeWille, J.W. (2006) Promoter
methylation reduces C/EBPdelta (CEBPD) gene expression in the
SUM-52PE human breast cancer cell line and in primary breast
tumors. Breast Cancer Res Treat, 95, 161-170.
49. Weinberg, R.A. (1995) The retinoblastoma protein and cell cycle
control. Cell, 81, 323-330.
50. Fawcett, T.W., Eastman, H.B., Martindale, J.L. and Holbrook, N.J.
53
(1996) Physical and functional association between GADD153 and
CCAAT/enhancer-binding protein beta during cellular stress. J Biol
Chem, 271, 14285-14289.
51. Wang, J.M., Tseng, J.T. and Chang, W.C. (2005) Induction of
human NF-IL6beta by epidermal growth factor is mediated through
the p38 signaling pathway and cAMP response element-binding
protein activation in A431 cells. Mol Biol Cell, 16, 3365-3376.