|
|
|
|
|
|
||
|
|
||||
|
|
||||
|
||||
Tumor Biology |
The University of Texas M.D. Anderson Cancer Center, Department of Neuro-Oncology, Houston, TX 77030
2 Address correspondence and reprint requests to W.K. Alfred Yung Chairman Ad Interim, Department of Neuro-Oncology, Box 100, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX, 77030.
Abstract
Ras activation occurs through stimulation of an upstream growth factor receptor such as epidermal growth factor receptor (EGFR). The ultimate effect of Ras is to induce nuclear transcription via a signaling pathway sequentially involving Raf, MAP kinase kinase (MEK), and mitogen-activated protein kinase (MAPK). To transform cells, Ras oncoproteins must be posttranslationally modified with a farnesyl group in a reaction catalyzed by farnesyl protein transferase. Farnesyltransferase inhibitors, therefore, have been proposed as potent anticancer agents. This study demonstrates the growth-inhibitory effects of farnesyltransferase inhibitor SCH66336 on human glioblastoma cell lines U-251 MG, U-251/E4 MG (a stably transfected cell line with elevated EGFR expression), and U-87 MG. As determined by (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl-2-(4-sulfophenyl)-2H-tetraz olium, inner salt) (MTS) and viability assays, the concentration required to achieve 50% inhibition (IC50) ranged from 30 µM (single 24-h treatment) to 10 µM (5-day treatment). U-251/E4 MG with overexpression of EGFR were more sensitive than U-251 MG parental cells. These observations were also supported by soft agar analysis. Cells treated with SCH66336 underwent G2 arrest. Western blot analysis revealed a decrease in phospho-MAPK levels upon treatment with 10 µM SCH66336, whereas MAPK levels were unaffected by the drug. Interestingly, increased expression of EGFR was observed in U-251 MG and U-251/E4 MG but not in U-87 MG in the presence of the inhibitor. These results demonstrate that SCH66336 inhibits viability and anchorage-independent growth in a time- and dose-dependent manner in glioblastoma cell lines U-251 MG, U-251/E4 MG, and U-87 MG via a signal transduction pathway involving the down-regulation of phospho-MAPK. Overexpression of EGFR appears to alter cellular sensitivity to farnesyltransferase inhibitors. This may have a particularly important implication in glioblastoma, where over 50% of tumors have amplification and overexpression of EGFR.
References
Bos, J.L. (1990) Ras gene mutations and human cancer. In: Cossman, J. (Ed.), Molecular Genetics in Cancer Diagnosis. Amsterdam: Elsevier Scientific Publishing Co. pp.273 -287.
Bredel, M., and Pollack, I.F. (1999) The p21-Ras signal transduction pathway and growth regulation in human high-grade gliomas. Brain Res. Rev. 29,232 -249.[CrossRef][Medline]
Bredel, M., Pollack, I.F., Freund, J.M., Hamilton, A.D., and Sebti, S.M. (1998) Inhibition of Ras and related G-proteins as a therapeutic strategy for blocking malignant glioma growth. Neurosurgery 43,124 -131.[ISI][Medline]
Feldkamp, M.M., Lala, P., Lau, N., Roncari, L., and Guha, A. (1999) Expression of activated epidermal growth factor receptors, Ras-guanosine triphosphate, and mitogen-activated protein kinase in human glioblastoma multiforme specimens. Neurosurgery 45,1442 -1453.[CrossRef][ISI][Medline]
Gerosa, M.A., Talarico, D., Fognani, C., Raimondi, E., Colombatti,
M., Tridente, G., De Carli, L., and Della Valle, G. (1989)
Overexpression of N-ras oncogene and epidermal growth factor receptor
gene in human glioblastomas. J. Natl. Cancer Inst.
81, 63-67.
Guha, A., Feldkamp, M.M., Lau, N., Boss, G., and Pawson, A. (1997) Proliferation of human malignant astrocytomas is dependent on Ras activation. Oncogene 15,2755 -2765.[CrossRef][ISI][Medline]
Gutmann, D.H., Giordano, M.J., Mahadeo, D.K., Lau, N., Silbergeld, D., and Guha, A. (1996) Increased neurofibromatosis 1 gene expression in astrocytic tumors: Positive regulation by p21ras.Oncogene 12,2121 -2127.[ISI][Medline]
James, G.L., Goldstein, J.L., Brown, M.S., Rawson, T.E., Somers,
T.C., McDowell, R.S., Crowley, C.W., Lucas, B.K., Levinson, A.D., and
Marsters, J.C., Jr. (1993) Benzodiazepine peptidomimetics: Potent
inhibitors of Ras farnesylation in animal cells.
Science 260,1937
-1942.
Klarlund, J.K., Cherniack, A.D., and Czech, M.P.
(1995) Divergent mechanisms for homologous desensitization of
p21ras by insulin and growth factors. J. Biol.
Chem. 270,23421
-23428.
Kohl, N.E., Wilson, F.R., Mosser, S.D., Giuliani, E., deSolms,
S.J., Conner, M.W., Anthony, N.J., Holtz, W.J., Gomez, R.P., Lee, T.J., Smith,
R.L., Graham, S.L., Hartman, G., Gibbs, J.B., and Oliff, A.
(1994) Protein farnesyltransferase inhibitors block the growth of
Ras-dependent tumors in nude mice. Proc. Natl. Acad. Sci.
U.S.A. 91,9141
-9145.
Kohl, N.E., Omer, C.A., Conner, M.W., Anthony, N.J., Davide, J.P., deSolms, S.J., Guiliani, E.A., Gomez, R.P., Graham, S.L., Hamilton, K., Handt, L.K., Hartman, G.D., Koblan, K.S., Kral, A.M., Miller, P.J., Mosser, S.O., O'Neill, T.J., Rands, E., Schaber, M.D., Gibbs, J.B., and Oliff, A. (1995) Inhibition of farnesyltransferase induces regression of mammary and salivary carcinomas in ras transgenic mice. Nat. Med. 1,792 -797.[CrossRef][ISI][Medline]
Lebowitz, P.F., Sakamuro, D., and Prendergast, G.C.
(1997) Farnesyl transferase inhibitors induce apoptosis of
Ras-transformed cells denied substratum attachment. Cancer
Res. 57,708
-713.
Lewin, B. (1997) Signal transduction. In: Lewin, B. (Ed.), Genes VI. New York: Oxford University Press Inc. pp. 1054-1085.
Libermann, T.A., Nusbaum, H.R., Razon, N., Kris, R., Lax, I., Soreq, H., Whittle, N., Waterfield, M.D., Ullrich, A., and Schlessinger, J. (1985) Amplification, enhanced expression, and possible rearrangement of EGF receptor gene in primary human brain tumours of glial origin. Nature 313,144 -147.[CrossRef][Medline]
Nagase, T., Kawata, S., Tamura, S., Matsuda, Y., Inui, Y., Yamasaki, E., Ishiguro, H., Ito, T., and Matsuzawa, Y. (1996) Inhibition of cell growth of human hepatoma cell line (Hep G2) by a farnesyl protein transferase inhibitor: A preferential suppression of Ras farnesylation. Int. J. Cancer 65,620 -626.[CrossRef][ISI][Medline]
Nagasu, T., Yoshimatsu, K., Rowell, C., Lewis, M.D., and Garcia,
A.M. (1995) Inhibition of human tumor xenograft growth by
treatment with the farnesyl transferase inhibitor B956. Cancer
Res. 55,5310
-5314.
Olson, J.J., James, C.D., Krisht, A., Barnett, D., and Hunter, S. (1995) Analysis of epidermal growth factor receptor gene amplification and alteration in stereotactic biopsies of brain tumors. Neurosurgery 36,740 -748.[ISI][Medline]
Orian, J.M., Vasilopoulos, K., Yoshida, S., Kaye, A.H., Chow, C.W., and Gonzales, M.F. (1992) Overexpression of multiple oncogenes related to histological grade of astrocytic glioma. Br. J. Cancer 66,106 -112.[ISI][Medline]
Osterop, A.P., Medema, R.H., v.d. Zon, G.C., Bos, J.L., Moller, M., and Maasen, J.A. (1993) Epidermal-growth-factor receptors generate Ras. GTP more efficiently than insulin receptors. Eur. J. Biochem. 212,477 -482.[ISI][Medline]
Pollack, I.F., Bredel, M., and Erff, M. (1998) Application of signal transduction inhibition as a therapeutic strategy for central nervous system tumors. Pediatr. Neurosurg. 29,228 -244.[CrossRef][ISI][Medline]
Prigent, S.A., Nagane, M., Lin, H., Huvar, I., Boss, G.R.,
Feramisco, J.R., Cavenee, W.K., and Huang H.S. (1996) Enhanced
tumorigenic behavior of glioblastoma cells expressing a truncated epidermal
growth factor receptor is mediated through the Ras-shc-grb2 pathway.
J. Biol. Chem. 271,25639
-25645.
Sepp-Lorenzino, L., Ma, Z., Rands, E., Kohl, N.E., Gibbs, J.B.,
Oliff, A., and Rosen, N. (1995) A peptidomimetic inhibitor of
farnesyl:protein transferase blocks the anchorage-dependent and-independent
growth of human tumor cell lines. Cancer Res.
55,5302
-5309.
Steck, P.A., Lee, P., Hung, M.C., and Yung, W.K.
(1988) Expression of an altered epidermal growth factor receptor
by human glioblastoma cells. Cancer Res.
48,5433
-5439.
Sun, J., Qian, Y., Hamilton, A.D., and Sebti, S.M.
(1995) Ras CAAX peptidomimetic FTI 276 selectively blocks tumor
growth in nude mice of a human lung carcinoma with K-ras mutation and
p53 deletion. Cancer Res.
55,4243
-4247.
Suzuki, N., Del Villar, K., and Tamanoi, F. (1998)
Farnesyltransferase inhibitors induce dramatic morphological changes of KNRK
cells that are blocked by microtubule interfering agents. Proc.
Natl. Acad. Sci. U.S.A. 95,10499
-10504.
Travis, J. (1993) Novel anticancer agents move closer
to reality. Science 260,1877
-1878.
Vogt, A., Sun, J., Qian, Y., Hamilton, A.D., and Sebti, S.M.
(1997) The geranylgeranyltransferase-I inhibitor GGTI-298 arrests
human tumor cells in G0/G1 and induces
p21WAF1/CIP1/SDI1 in a p53-dependent manner. J. Biol.
Chem. 272,27224
-27229.
Westermark, B., Heldin, C.H., and Nister, M. (1995) Platelet-derived growth factor in human glioma. Glia 15,257 -263.[CrossRef][ISI][Medline]
Wong, A.J., Bigner, S.H., Bigner, D.D., Kinzler, K.W., Hamilton,
S.R., and Vogelstein, B. (1987) Increased expression of the
epidermal growth factor receptor gene in malignant gliomas is invariably
associated with gene amplification. Proc. Natl. Acad. Sci.
U.S.A. 84,6899
-6903.
This article has been cited by other articles:
|
|
 |
|
  S. H. Oh, Q. Jin, E. S. Kim, F. R. Khuri, and H.-Y. Lee Insulin-like Growth Factor-I Receptor Signaling Pathway Induces Resistance to the Apoptotic Activities of SCH66336 (Lonafarnib) through Akt/Mammalian Target of Rapamycin-Mediated Increases in Survivin Expression Clin. Cancer Res., March 1, 2008; 14(5): 1581 - 1589. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Sathornsumetee, A. B. Hjelmeland, S. T. Keir, R. E. McLendon, D. Batt, T. Ramsey, N. Yusuff, B.K. A. Rasheed, M. W. Kieran, A. Laforme, et al. AAL881, a Novel Small Molecule Inhibitor of RAF and Vascular Endothelial Growth Factor Receptor Activities, Blocks the Growth of Malignant Glioma. Cancer Res., September 1, 2006; 66(17): 8722 - 8730. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Z.-y. Huang, Y. Wu, S. P. Burke, and D. H. Gutmann The 43,000 Growth-associated Protein Functions as a Negative Growth Regulator in Glioma Cancer Res., June 1, 2003; 63(11): 2933 - 2939. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. M. Fathallah-Shaykh Darts in the Dark Cure Animal, but Not Human, Brain Tumors Arch Neurol, May 1, 2002; 59(5): 721 - 724. [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|
