| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Experimental Therapeutics |
Cell Biology Program [L. M. B., A. R., R. A. R., P. A. M., V. M. R.], Laboratory of Tumor Biology [D. B. A., B. H.], Genitourinary Oncology Service [H. I. S.], Department of Pathology [C. C-C.], and Department of Epidemiology and Biostatistics Service [H. T. T.], Memorial Sloan-Kettering Cancer Center, New York, New York 10021
 |
ABSTRACT |
|---|
 Top ABSTRACT INTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
|
INTRODUCTION |
|---|
|
TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
SAHA and other hydroxamic acid-based HPCs are potent inhibitors of HDACs (4 , 8) . We have shown previously that SAHA inhibits partially purified HDACs 1 and 3 at concentrations as low as 100 nM and causes an accumulation of acetylated histones in cells in culture at low micromolar concentrations (4) . The active catalytic site in HDACs is evolutionarily conserved and consists of a core pocket with a zinc atom at the base of the pocket (8) . Cocrystals of SAHA and a HDAC-like protein have shown that SAHA fits into the core pocket of HDAC-like protein, and its hydroxamic acid moiety interacts directly with the zinc atom in the catalytic site (8) . The acetylation of nucleosomal histones is regulated by the opposing activities of HDACs and histone acetyltransferases such as cAMP-responsive element binding protein-binding protein/p300, which are components of multiprotein complexes associated with gene promoters. It has been postulated that hypoacetylated histones maintain the repressed state of a gene by condensing the associated chromatin and restricting the access of transcription factors to the DNA, whereas acetylation of histones is generally associated with activation of gene expression (9 , 10) . Inhibition of HDACs by SAHA may contribute to the induction of differentiation or apoptosis in transformed cells by activating transcription of target genes.
Cancer of the prostate is a major health problem and is the second highest cause of deaths from cancer each year in males in the United States. The current treatment for most prostate cancers that have spread beyond the prostate gland is surgical or chemical castration, which causes regression of the tumor due to the dependence of prostatic epithelial cells on physiological levels of circulating androgens for growth and survival. Whereas this treatment may be initially successful, most tumors eventually recur due to the expansion of an androgen-insensitive population of tumor cells. Treatment of androgen-independent tumors with cytotoxic agents is generally unsatisfactory, and, at this stage, the disease is usually fatal to the patient (11) .
Agents that induce differentiation and/or apoptosis of prostate cancer cells may provide an alternative or additional approach to the treatment of this disease. Several classes of differentiating agents, including SAHA (5) , butyrate and its analogues (12, 13, 14, 15) , retinoids (16, 17, 18) , and vitamin D analogues (17, 18, 19, 20, 21, 22) , are reported to inhibit the growth of prostate cancer cells in culture and cause a shift in cellular phenotype toward a more differentiated epithelioid morphology. In this study, we tested the activity of SAHA in three prostate cancer cell lines (LNCaP, PC-3, and TSU-Pr1) and evaluated the antitumor effects of SAHA in vivo using the CWR22 human prostate cancer xenograft model in nude mice. CWR22 is an androgen-dependent tumor derived from a patient with metastatic prostate cancer (23 , 24) that can be grown s.c. in nude mice. The tumors regress significantly after castration of the host mice, and this regression is preceded by a several thousand-fold reduction in serum PSA levels. The reduction in tumor volume is maintained for 80–400 days, after which androgen-independent CWR22 tumors emerge in the castrated hosts and grow until the animal must be sacrificed (25 , 26) . The initial response of the primary CWR22 tumors to androgen ablation and the later growth of androgen-independent tumors mimic the clinical events of human prostate cancer, making this an attractive model for the evaluation of the efficacy of SAHA in vivo. Furthermore, in ex vivo histocultures, these tumors have gene expression profiles and changes in PSA expression and sensitivity to cytotoxic drugs similar to those seen in human prostate tumors (27) . Here, we show that SAHA inhibits the proliferation of prostate cancer cell lines in culture and markedly suppresses the growth of CWR22 tumors in nude mice at doses that cause little evident toxicity.
|
MATERIALS AND METHODS |
|---|
|
TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
SAHA was synthesized as described previously (3) and dissolved and diluted in DMSO. The effect of SAHA on the viability of prostate cancer cells was determined by cell counting using a hemocytometer. Cells were seeded in triplicate in 24-well dishes at a density of 3 x 104 cells/well. Cells were allowed to attach overnight, and then the medium was replaced with medium containing the appropriate concentration of SAHA (0, 2.5, 5, or 7.5 µM). Cells were counted at various times after the start of SAHA treatment, and cell viability was assessed by trypan blue dye exclusion.
Preparation of the CWR22 Prostate Cancer Xenografts.
The CWR22 human prostate cancer xenograft was kindly provided by Dr.
Thomas G. Pretlow (Case Western Reserve University, Cleveland, OH).
Male BALB/c nude (nu/nu) mice were purchased at 4–6 weeks
of age from the National Cancer Institute-Frederick Cancer Research &
Development Center. Mice were housed under barrier conditions
and maintained on a 12-h light/12-h dark cycle, with food and water
supplied ad libitum. Two days before inoculation of the mice
with tumor cells, a 90-day sustained-release 12.5-mg testosterone
pellet (Innovative Research of America, Sarasota, FL) was implanted in
the left flank. To inoculate mice with the CWR22 tumor cells, an
established tumor was removed from a host mouse, minced finely through
a mesh support, and suspended in RPMI 1640. An equal volume of the
tumor cell suspension was injected s.c. in the right flank of each
mouse. After 7 days, a palpable tumor of approximately 5 x 5 mm was detected in the inoculated animals.
SAHA Preparation and Administration.
Mice with palpable CWR22 tumors were divided into four groups (eight or
nine mice/group) for the treatment study. All mice in each treatment
group had tumors of similar size (5 x 5 mm) at the
start of treatment. For administration to mice, SAHA was dissolved and
diluted in a vehicle of DMSO. Each group of mice received 25, 50, or
100 mg/kg SAHA daily by i.p. injection for 21 days. A control group of
eight animals was injected with vehicle only (DMSO). The injection
volume was kept constant at 1 µl/gram body weight. The mice were
weighed three times during the experimental period to assess toxicity
of the treatments, and the tumors were measured twice weekly using
calipers. Tumor volume was calculated from the two-dimensional caliper
measurements using the following formula: tumor volume = length x (width)2 x 
/6.
The treatment period was completed after 21 days, when the vehicle-treated group of mice had large tumors, requiring that the animals be sacrificed. On the final day of the study, all mice were sacrificed by carbon dioxide inhalation, and blood was taken from each animal by cardiac puncture. The s.c. tumor was removed and divided into two pieces, one of which was snap frozen in liquid nitrogen, and one of which was fixed in formalin and embedded in paraffin. At the end of the experimental period, one animal from each dose group was submitted to an animal pathologist at the Research Animal Resource Center of Cornell University Medical College and Memorial Sloan-Kettering Cancer Center for a complete tissue necropsy and blood cell analysis. Necropsies were also performed on two mice that died during the study.
Statistical Analyses.
Tumor growth curves are presented in terms of treatment group means and
SEs. Statistical significance of treatment effect was assessed by
repeated-measures ANOVA after applying a power transformation to
equalize residual variances and linearize the tumor growth curves. We
report Bonferroni-adjusted Ps for all pairwise comparisons
of growth curve slopes between SAHA dose groups.
Analysis of Serum PSA Levels.
Levels of PSA protein were measured in the serum of all animals at
three different time points during the treatment period. Blood samples
(approximately 50 µl) were taken from the tail of each mouse at the
start of treatment (day 0) and at day 9 of the protocol, and a cardiac
bleed was performed on each mouse at the time of sacrifice (day 21).
PSA was detected in the serum using a Tandem-R radioimmunometric assay
(Hybritech, San Diego, CA).
Detection of PSA mRNA by Northern Blot.
Expression of PSA mRNA by the CWR22 tumor cells was analyzed for two
animals in each treatment group by Northern blotting. Total RNA was
extracted from the excised tumors by the guanidine
isothiocyanate/phenol/chloroform method (28)
. RNA (20
µg) was electrophoresed through a 1% agarose gel containing 17%
formaldehyde. The RNA was blotted onto Hybond-N membranes (Amersham,
Buckinghamshire, United Kingdom) using standard techniques, and the
blots were hybridized with a 510-bp 32P-labeled
PSA cDNA probe.
Histone Acetylation in LNCaP Cells and CWR22 Tumors.
Histones were isolated from LNCaP cells by rinsing dishes of
5 x 106 cells with ice-cold PBS
and then scraping the cells in 10 ml of ice-cold PBS. Cells were
centrifuged at 1000 rpm for 5 min, and the pellet was resuspended in 1
ml of histone lysis buffer [8.6% sucrose, 1% Triton X-100, 50
mM sodium bisulfite, 10 mM Tris-HCl (pH 6.5),
and 10 mM MgCl2] and Dounce
homogenized. Lysates were centrifuged at 700 rpm for 5 min, and the
nuclear pellet was washed three times with the lysis buffer and once
with 10 mM Tris-HCl (pH 7.4) and 13 mM EDTA.
Histones were then acid extracted from the nuclear pellets as described
previously (29)
. CWR22 tumors were homogenized directly in
histone lysis buffer, and histones were isolated from the cell lysates
as described above. Acetylation of core histones in the cells or tumors
was determined by Western blotting using rabbit polyclonal antibodies
against acetylated histone H3 or H4 (Upstate Biotechnology, Lake
Placid, NY) and visualized using the Super Signal chemiluminescence
system (Pierce, Rockford, IL), as described previously
(30)
.
|
RESULTS |
|---|
|
TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
. Culture with 2.5 µM SAHA caused
complete growth suppression of the androgen-sensitive LNCaP cells but
little evident induction of cell death as assayed by trypan blue dye
exclusion. At concentrations of 5 and 7.5 µM,
SAHA induced cell death in the LNCaP cells within 48 h of culture
(Fig. 1A)
. Culture with SAHA at the indicated concentrations
caused growth suppression of the androgen-insensitive cell lines PC-3
and TSU-Pr1 with little detectable cell death (Fig. 1A)
.
|
. Cells treated without or
with 0.005 or 0.05 µM SAHA had similar baseline
levels of acetylated histones H3 and H4 (Fig. 1B)
. An
incremental accumulation of acetylated histones H3 and H4 was observed
in cells cultured with 0.5 and 2 µM SAHA. No
further increase was observed after culture with 5
µM SAHA.
Efficacy and Toxicity of SAHA in the CWR22 Prostate Xenograft
Model.
The activity of SAHA against the growth of prostate cancer cells
in vivo was examined in the androgen-dependent CWR22 human
prostate cancer xenograft, which was grown s.c. in nude mice. Daily
administration of SAHA caused significant suppression of the growth of
established CWR22 tumors, such that doses of 25, 50, and 100 mg/kg/day
caused reductions of 78%, 97%, and 97%, respectively, in the mean
final tumor volume compared with vehicle-treated control animals (Fig. 2)
. Tumor regression (a reduction in tumor size relative to the size of
the tumor at the initiation of treatment) was observed in one of eight
mice receiving 25 mg/kg/day SAHA and in five of nine mice receiving 50
mg/kg/day SAHA. In the five animals receiving 100 mg/kg/day SAHA that
survived for at least 20 days of treatment, three showed tumor
regression.
|
. One of the nine mice from the 50 mg/kg/day SAHA treatment group died
on the penultimate day of the study but had no preceding weight loss,
suggesting that death may have been due to an injection injury. The
mice in this group gained on average 1.0 gram in body weight relative
to their weight at the initiation of treatment (Table 1)
. Five of the
nine mice receiving 100 mg/kg/day SAHA died during the study, and each
of the mice that died experienced 1–2 days of rapid weight loss before
death, suggesting that this is a toxic dose level. Surviving mice in
this dose group had an average weight loss of 0.8 grams relative to
their weight at the start of treatment.
|
Necropsies were also performed on two of the animals that died in the 100 mg/kg/day SAHA treatment group. Both mice showed inflammation and bacterial infection at the site of injection, suggesting that acute peritonitis may have been a factor in the cause of death. These mice also had suppressed erythropoiesis in the spleen and bone marrow.
The striking finding is that 50 mg/kg/day SAHA for 21 days caused marked to complete suppression of CWR22 prostate tumor growth without apparent toxicity. At 25 mg/kg/day, there was no apparent toxicity, but the suppression of tumor growth was less; whereas at 100 mg/kg/day, there was marked to complete suppression of tumor growth associated with evidence of toxicity.
Serum PSA Levels.
PSA was measured in blood samples taken from each animal at days 0, 9,
and 21 of the treatment period. There were no significant differences
in the serum levels of PSA among the tumor-bearing experimental groups
before treatment (Fig. 3A)
. In the animals receiving vehicle, PSA levels increased
approximately 47-fold over the 21-day experimental period (Fig. 3A)
, in agreement with previous findings that serum PSA
levels rise in proportion to the increasing tumor burden
(24)
. In each of the SAHA-treated groups of mice, the
serum PSA concentration also increased over time but did so at a lower
rate (Fig. 3A)
. Northern analysis on RNA extracted from two
tumors in each treatment group revealed a treatment dose-dependent
increase in the levels of PSA mRNA in the SAHA-treated groups compared
with vehicle-treated controls (Fig. 3B)
.
|
CWR22 tumors from mice treated with vehicle alone had low baseline
levels of acetylated histones H3 and H4 (Fig. 4)
. At 6 h after injection of SAHA, an increased accumulation of
acetylated histones H3 and H4 was present in tumors from one animal
receiving 25 mg/kg SAHA and in both animals receiving 50 mg/kg SAHA
(Fig. 4)
. By 12 h after injection of SAHA, the accumulation of
acetylated histones was reduced to the level seen in vehicle-treated
controls. These findings are consistent with the relatively short
half-life of SAHA (15–20 min) that we have determined in a mouse,
dogs, and humans (data not shown).
|
|
DISCUSSION |
|---|
|
TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
s.c. growth of the CWR22 xenograft in nude mice is usually associated with an increase in serum levels of PSA that correlates with tumor burden (24) . We had similar findings in the prostate tumor-bearing animals not receiving SAHA. In animals treated with SAHA (50 mg/kg), despite an almost complete suppression of CWR22 tumor growth, serum PSA levels rose 12-fold. Northern blot analysis to evaluate gene expression in prostate tumors revealed that the rise in serum PSA levels in SAHA-treated mice was correlated with an induction of PSA mRNA. These findings indicate that serum PSA levels may not be a good surrogate marker of tumor burden or disease progression after treatment with SAHA. Induction of PSA expression in prostate cancer cells has also been observed with other agents that suppress the growth of prostate cell lines in vitro and/or in vivo, including butyrate analogues (14 , 15) , retinoids (17) , and vitamin D3 analogues (17 , 21) .
One of the well-characterized biochemical effects of SAHA and other hydroxamic acid-based HPCs is increased accumulation of acetylated core histones caused by inhibition of HDAC activity (4 , 8 , 30 , 31) . In the present study, accumulation of acetylated histones was demonstrated in LNCaP prostate cells treated with SAHA in culture and in CWR22 tumors from mice treated with SAHA. Within 3 h of culture with SAHA, an increased accumulation of acetylated histones was detected in LNCaP cells. Similarly, in vivo, within 6 h of SAHA administration to mice, increased accumulation of acetylated histones was observed in CWR22 tumors from one of two mice receiving 25 mg/kg SAHA and in two of two mice receiving 50 mg/kg SAHA. Observations in our laboratory and other laboratories indicate that histone acetylation increases in both normal and tumor cells after treatment with HDAC inhibitors (31) .4 Nevertheless, the growth-suppressive and apoptotic activity of these agents appears to be confined to transformed cells. Treatment of normal human fibroblasts or melanocytes with the HPCs azelaic bishydroxamic acid or azelaic-1-hydroxamate-9-anilide causes no growth inhibition at doses that suppress the growth of transformed cell lines (31 , 32) , although both the normal and transformed cells show similar increases in histone acetylation (31) . Furthermore, azelaic-1-hydroxamate-9-anilide, azelaic bishydroxamic acid, and SAHA each suppress the growth of tumor xenografts in vivo at doses that cause little or no apparent toxicity to the animals (31) . The mechanism of this selectivity is not yet understood. Hyperacetylation of the histones in either normal or tumor cells may prove to be a useful intermediate marker for biological activity of the HDAC inhibitors in the design of preclinical and clinical trials of these agents.
|
ACKNOWLEDGMENTS |
|---|
|
FOOTNOTES |
|---|
1 This study was supported in part by grants from
CaPCURE (to D. B. A. and H. I. S.), the PepsiCo Foundation
(to D. B. A., H. I. S., and C. C-C.), the Burke Foundation (to
L. M. B. and H. I. S.), the American Cancer Society (to
D. B. A.), the Eleanor and Paul Stephens Foundation (to D. B. A.),
the Japan Foundation for Promotion of Cancer Research, and the DeWitt
Wallace Fund for Memorial Sloan-Kettering Cancer Center and by NIH
Grants CA-DK-47650 (to C. C-C.) and CA-0974823 (to R. A. R. and
P. A. M.). D. B. A. was supported by a CaPCURE Young
Investigator Award. 
2 To whom requests for reprints should be
addressed, at Cell Biology Program, Memorial Sloan-Kettering Cancer
Center, 1275 York Avenue, New York, NY 10021. Phone: (212) 639-6573;
Fax: (212) 639-2861; E-mail: v-richon{at}ski.mskcc.org
3 The abbreviations used are: SAHA,
suberoylanilide hydroxamic acid; HDAC, histone deacetylase; HPC, hybrid
polar compound; PSA, prostate-specific antigen.
4 L. M. Butler and V. M. Richon, unpublished
observations.
Received 2/10/00. Accepted 7/14/00.
|
REFERENCES |
|---|
|
TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
,25-dihydroxycholecalciferol, all-trans retinoic acid, 9-cis retinoic acid, and phenylacetate. Prostate, 28: 182-194, 1996.[Medline]
,25-dihydroxyvitamin D3 in seven human prostatic carcinoma cell lines. Clin. Cancer Res., 1: 997-1003, 1995.[Abstract]
This article has been cited by other articles:
|
|
 |
|
  P. Gallo, M. V.G. Latronico, P. Gallo, S. Grimaldi, F. Borgia, M. Todaro, P. Jones, P. Gallinari, R. De Francesco, G. Ciliberto, et al. Inhibition of class I histone deacetylase with an apicidin derivative prevents cardiac hypertrophy and failure Cardiovasc Res, August 27, 2008; (2008) cvn215v2. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. S. Makki, T. Heinzel, and C. Englert TSA downregulates Wilms tumor gene 1 (Wt1) expression at multiple levels Nucleic Acids Res., July 1, 2008; 36(12): 4067 - 4078. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Miyanaga, A. Gemma, R. Noro, K. Kataoka, K. Matsuda, M. Nara, T. Okano, M. Seike, A. Yoshimura, A. Kawakami, et al. Antitumor activity of histone deacetylase inhibitors in non-small cell lung cancer cells: development of a molecular predictive model Mol. Cancer Ther., July 1, 2008; 7(7): 1923 - 1930. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R Glauben, A Batra, T Stroh, U Erben, I Fedke, H A Lehr, F Leoni, P Mascagni, C A Dinarello, M Zeitz, et al. Histone deacetylases: novel targets for prevention of colitis-associated cancer in mice Gut, May 1, 2008; 57(5): 613 - 622. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. A. Hassig, K. T. Symons, X. Guo, P.-M. Nguyen, T. Annable, P. L. Wash, J. E. Payne, D. A. Jenkins, C. Bonnefous, C. Trotter, et al. KD5170, a novel mercaptoketone-based histone deacetylase inhibitor that exhibits broad spectrum antitumor activity in vitro and in vivo Mol. Cancer Ther., May 1, 2008; 7(5): 1054 - 1065. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Fournel, C. Bonfils, Y. Hou, P. T. Yan, M.-C. Trachy-Bourget, A. Kalita, J. Liu, A.-H. Lu, N. Z. Zhou, M.-F. Robert, et al. MGCD0103, a novel isotype-selective histone deacetylase inhibitor, has broad spectrum antitumor activity in vitro and in vivo Mol. Cancer Ther., April 1, 2008; 7(4): 759 - 768. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Fan, J. Stanfield, Y. Guo, J. A. Karam, E. Frenkel, X. Sun, and J.-T. Hsieh Effect of Trans-2,3-Dimethoxycinnamoyl Azide on Enhancing Antitumor Activity of Romidepsin on Human Bladder Cancer Clin. Cancer Res., February 15, 2008; 14(4): 1200 - 1207. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
V. R. Fantin and V. M. Richon Mechanisms of Resistance to Histone Deacetylase Inhibitors and Their Therapeutic Implications Clin. Cancer Res., December 15, 2007; 13(24): 7237 - 7242. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. M. Gillenwater, M. Zhong, and R. Lotan Histone deacetylase inhibitor suberoylanilide hydroxamic acid induces apoptosis through both mitochondrial and Fas (Cd95) signaling in head and neck squamous carcinoma cells Mol. Cancer Ther., November 1, 2007; 6(11): 2967 - 2975. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Ishihama, M. Yamakawa, S. Semba, H. Takeda, S. Kawata, S. Kimura, and W. Kimura Expression of HDAC1 and CBP/p300 in human colorectal carcinomas J. Clin. Pathol., November 1, 2007; 60(11): 1205 - 1210. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T.-M. Lee, M.-S. Lin, and N.-C. Chang Inhibition of histone deacetylase on ventricular remodeling in infarcted rats Am J Physiol Heart Circ Physiol, August 1, 2007; 293(2): H968 - H977. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. A. Olsen, Y. H. Kim, T. M. Kuzel, T. R. Pacheco, F. M. Foss, S. Parker, S. R. Frankel, C. Chen, J. L. Ricker, J. M. Arduino, et al. Phase IIB Multicenter Trial of Vorinostat in Patients With Persistent, Progressive, or Treatment Refractory Cutaneous T-Cell Lymphoma J. Clin. Oncol., July 20, 2007; 25(21): 3109 - 3115. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Sharma, C. E.S. Comstock, E. S. Knudsen, K. H. Cao, J. K. Hess-Wilson, L. M. Morey, J. Barrera, and K. E. Knudsen Retinoblastoma Tumor Suppressor Status Is a Critical Determinant of Therapeutic Response in Prostate Cancer Cells Cancer Res., July 1, 2007; 67(13): 6192 - 6203. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Alimirah, J. Chen, F. J. Davis, and D. Choubey IFI16 in Human Prostate Cancer Mol. Cancer Res., March 1, 2007; 5(3): 251 - 259. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Vlasakova, Z. Novakova, L. Rossmeislova, M. Kahle, P. Hozak, and Z. Hodny Histone deacetylase inhibitors suppress IFN{alpha}-induced up-regulation of promyelocytic leukemia protein Blood, February 15, 2007; 109(4): 1373 - 1380. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. C. Myzak, P. Tong, W.-M. Dashwood, R. H. Dashwood, and E. Ho Sulforaphane Retards the Growth of Human PC-3 Xenografts and Inhibits HDAC Activity in Human Subjects Experimental Biology and Medicine, February 1, 2007; 232(2): 227 - 234. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Yin, J. M. Ong, J. Hu, J. C. Desmond, N. Kawamata, B. M. Konda, K. L. Black, and H. P. Koeffler Suberoylanilide Hydroxamic Acid, a Histone Deacetylase Inhibitor: Effects on Gene Expression and Growth of Glioma Cells In vitro and In vivo Clin. Cancer Res., February 1, 2007; 13(3): 1045 - 1052. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. B. Arnold, N. Arkus, J. Gunn, and M. Korc The Histone Deacetylase Inhibitor Suberoylanilide Hydroxamic Acid Induces Growth Inhibition and Enhances Gemcitabine-Induced Cell Death in Pancreatic Cancer Clin. Cancer Res., January 1, 2007; 13(1): 18 - 26. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. L. Marrocco, W. D. Tilley, T. Bianco-Miotto, A. Evdokiou, H. I. Scher, R. A. Rifkind, P. A. Marks, V. M. Richon, and L. M. Butler Suberoylanilide hydroxamic acid (vorinostat) represses androgen receptor expression and acts synergistically with an androgen receptor antagonist to inhibit prostate cancer cell proliferation Mol. Cancer Ther., January 1, 2007; 6(1): 51 - 60. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Duvic, R. Talpur, X. Ni, C. Zhang, P. Hazarika, C. Kelly, J. H. Chiao, J. F. Reilly, J. L. Ricker, V. M. Richon, et al. Phase 2 trial of oral vorinostat (suberoylanilide hydroxamic acid, SAHA) for refractory cutaneous T-cell lymphoma (CTCL) Blood, January 1, 2007; 109(1): 31 - 39. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Faraco, T. Pancani, L. Formentini, P. Mascagni, G. Fossati, F. Leoni, F. Moroni, and A. Chiarugi Pharmacological Inhibition of Histone Deacetylases by Suberoylanilide Hydroxamic Acid Specifically Alters Gene Expression and Reduces Ischemic Injury in the Mouse Brain Mol. Pharmacol., December 1, 2006; 70(6): 1876 - 1884. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. Xu, L. Ngo, G. Perez, M. Dokmanovic, and P. A. Marks Intrinsic apoptotic and thioredoxin pathways in human prostate cancer cell response to histone deacetylase inhibitor PNAS, October 17, 2006; 103(42): 15540 - 15545. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X. Huang and B. Guo Adenomatous polyposis coli determines sensitivity to histone deacetylase inhibitor-induced apoptosis in colon cancer cells. Cancer Res., September 15, 2006; 66(18): 9245 - 9251. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. K. Kulp, C.-S. Chen, D.-S. Wang, C.-Y. Chen, and C.-S. Chen Antitumor Effects of a Novel Phenylbutyrate-Based Histone Deacetylase Inhibitor, (S)-HDAC-42, in Prostate Cancer Clin. Cancer Res., September 1, 2006; 12(17): 5199 - 5206. [Abstract] [Full Text] [PDF]
|
|
|
; 2.5 µM SAHA, 
; 5 µM SAHA, •; and
7.5 µM SAHA, 
. Cells were counted at the indicated
times using a hemocytometer, and the number of viable cells was
determined by trypan blue exclusion. The top panels show
the number of viable cells present at the time points indicated,
whereas the bottom panels show the number of dead cells
as a percentage of the total cells present in each culture. Data are
presented as the mean ± SE of triplicate values from a
typical experiment. B, LNCaP cells (5 x 106) were treated with the indicated concentrations of SAHA
for 3 h. Cells were harvested, and histones were prepared as
described in "Materials and Methods." Histone acetylation was
detected by Western blot using antibodies against acetylated H3 and H4.
The top panel contains acetylated histone H3, the
middle panel contains acetylated histone H4, and the
bottom panel shows a Coomassie blue-stained
polyacrylamide gel of the total histones extracted from the cells.
