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Query: UNIPROT:P04637 (
p53
)
77,613
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Patients with secondary hyperparathyroidism following chronic renal disease frequently develop hyperplastic parathyroids. Hyperplastic parathyroids have an increased number of chief cells, a decreased amount of stromal fat, and a nodular or diffuse histologic pattern. Hyperplastic parathyroids may also express higher proliferative activity compared with controls. We evaluated the morphologic features and immunohistochemical expression of
fatty acid synthase
(
FAS
), Ki67, proliferating cell nuclear antigen, and
p53 protein
in 78 hyperplastic parathyroids from 20 patients with secondary hyperparathyroidism. Twenty normal parathyroids incidentally removed during nonneoplastic thyroid surgery were used as controls. Our results showed that hyperplastic glands overexpress
FAS
(P =.06). Statistical analysis also revealed a significant association between
FAS
and
p53 protein
(P =.006) and between
FAS
and hyperplastic glands with a predominant nodular pattern (P =.02). Hyperplastic parathyroids from patients with chronic renal failure strongly express
FAS
. Fatty acid synthase may therefore be a potential biological indicator of highly proliferating parathyroid cells.
...
PMID:Immunohistochemical study of fatty acid synthase, Ki67, proliferating cell nuclear antigen, and p53 expression in hyperplastic parathyroids. 1055 75
The normal mucosa-adenoma-carcinoma sequence in colon pathology provides an attractive model of tumor progression. The role of tumor suppressor genes, oncogenes, and proliferative markers in tumorogenesis has evolved considerably in the last decade. By immunohistochemistry means, we have studied
p53
, bcl-2, c-myc, p21-ras, ki67, and
fatty acid synthase
(a fatty-acid-synthesizing enzyme) in normal, dysplastic, and neoplastic mucosa. The results were correlated with clinicopathological features and overall survival (OS). Formalin-fixed, paraffin-embedded archival material from 100 nonconsecutive adenomas and 100 adenocarcinomas (ADCs), including adjacent-to-tumor nonneoplastic mucosa (ANNM), from patients with a 5-year follow-up period were studied. Negative controls were obtained from colon resections for nonneoplastic disease. Fatty acid synthase was associated with ADC (P = 0.0001).
p53 protein
was associated with high-grade dysplasia adenoma (AHGD), ADC (P = 0.0001), and pT stage (P = 0.003). bcl-2 was associated with adenomas with low-grade dysplasia (P = 0.009); c-myc was associated with ANNM (P = 0.005) and pT stage (P = 0.006). p21-ras was associated with AHGD (P = 0.0001) and ANNM (P = 0.01). Ki67 was associated with AHGD (P = 0.02) and ADC (P = 0.0001). Univariate analysis on neoplastic tissue revealed histological grade, pT stage, pN stage, p21-ras, and
p53
to be significant markers of OS; p21-ras,
p53
, and c-myc were reliable markers when evaluated on ANNM. Multivariate analysis revealed pT stage, pN stage, and p21-ras to be independent prognosticators of OS on ADC; p21-ras and c-myc staining in the ANNM were correlated with worse survival (OS). We suggest that the evaluation in concert of clinicopathological data and immunohistochemical markers on both normal and abnormal colon tissue provides an attractive model of tumor progression; moreover, it may give important messages about the prediction of survival.
...
PMID:Immunohistochemical expression of fatty acid synthase, apoptotic-regulating genes, proliferating factors, and ras protein product in colorectal adenomas, carcinomas, and adjacent nonneoplastic mucosa. 1063 48
Diagnostic and prognostic markers for prostatic cancer (PCa) include conventional protein markers (e.g., PAP, PSA, PSMA, PIP,
OA-519
, Ki-67, PCNA, TF, collagenase, and TIMP 1), angiogenesis indicator (e.g., factor VIII), neuroendocrine differentiation status, adhesion molecules (E-cadherin, integrin), bone matrix degrading products (e.g., ICPT), as well as molecular markers (e.g., PSA, PSMA,
p53
, 12-LOX, and MSI). Currently, only PSA is used clinically for early diagnosis and monitoring of PCa. The histological differential diagnosis of prostatic adenocarcinoma includes normal tissues such as Cowper's gland, paraganglion tissue and seminal vesicle or ejaculatory duct as well as pathological conditions such as atypical adenomatous hyperplasia, atrophy, basal cell hyperplasia and sclerosing adenosis. A common PCa is characterized by a remarkable heterogeneity in terms of its differentiation, microscopic growth patterns and biological aggressiveness. Most PCa are multifocal with signi ficant variations in tumor grade between anatomically separated tumor foci. The Gleason grading system which recognizes five major grades defined by patterns of neoplastic growth has gained almost uniform acceptance. In predicting the biologic behavior of PCa clinical and pathological stages are used as the major prognostic indicators. Among the cell proliferation and death regulators androgens are critical survival factors for normal prostate epithelial cells as well as for the androgen-dependent human prostatic cancer cells. The androgen ablation has been shown to increase the apoptotic index in prostatic cancer patients and castration also promotes apoptotic death of human prostate carcinoma grown in mice. The progression of PCa, similarly to other malignancies, is a multistep process, accompanied by genetic and epigenetic changes, involving phenomenons as adhesion, invasion and angiogenesis (without prostate specific features).
...
PMID:Prostate Cancer - Old Problems and New Approaches. (Part II. Diagnostic and Prognostic Markers, Pathology and Biological Aspects). 1117 6
Fatty acid synthetic metabolism is abnormally elevated in tumor cells, and pharmacological inhibitors of the anabolic enzyme
fatty acid synthase
(
FAS
), including the natural product cerulenin and the novel synthetic compound c75, are selective inhibitors of tumor cell growth. We have recently reported that these two
FAS
inhibitors both produce rapid, potent inhibition of DNA replication and S-phase progression in human cancer cells, as well as apoptotic death. Here we report an additional characterization of the cellular response to
FAS
inhibition. RKO colon carcinoma cells were selected for study because they undergo little apoptosis within the first 24 h after
FAS
inhibition. Instead, RKO cells exhibited a biphasic stress response with a transient accumulation in S and G2 at 4 and 8 h that corresponds to a marked reduction in cyclin A- and B1-associated kinase activities, and then by accumulation of
p53
and p21 proteins at 16 and 24 h and growth arrest in G1 and G2. The response of RKO cells to
FAS
inhibition resembled a genotoxic stress response, but DNA damage did not appear to be an important downstream effect of
FAS
inhibition, because none was detected using the single cell gel electrophoresis assay (comet assay) to assess DNA damage.
p53
function is probably important in protecting RKO cells from
FAS
inhibition because, similar to many other tumor lines, RKO cells expressing a dominant negative mutant p53 gene underwent extensive apoptosis within 24 h after
FAS
inhibition. Sensitization of cells to
FAS
inhibitors by the loss of
p53
raises the possibility that these agents may be clinically useful against malignancies carrying
p53
mutations. Whereas induction of apoptosis appeared related to accumulation of the substrate, malonyl-CoA, after
FAS
inhibition, the cytostatic effects were independent of malonyl-CoA accumulation and may have resulted from product depletion.
...
PMID:Pharmacological inhibition of fatty acid synthase activity produces both cytostatic and cytotoxic effects modulated by p53. 1124 56
Primary hyperparathyroidism is the clinical result of parathyroid adenoma or hyperplasia, rarely of carcinoma. Clinical, serologic, and radiologic data are unable to discriminate a single parathyroid adenoma from an enlarged hyperplastic gland. Morphologic features also overlap in adenoma and small hyperplastic gland. Studying immunohistochemical expression of
fatty acid synthase
(
FAS
),
p53
, Ki67 and bcl-2, we found that among 21 adenomas 19 (90.5%) were positive for
FAS
, 12 (57.2%) for Ki67, 11 (52.4%) for
p53
, and 16 (76.2%) for bcl-2; among 12 hyperplasias, 12 (100%) were positive for
FAS
, 6 (50%) for KI67, 8 (66.7%) for
p53
, and 8 (66.7%) for bcl-2. Statistical analysis showed that
FAS
was associated with parathormone (PTH) (P =.001), Ki67 (P =.01), and
p53
(P =.01). Moreover,
FAS
was associated with hyperplastic (P =.0001) and adenomatous glands (P =.0001). Ki67 was associated with both adenomatous (P =.02) and hyperplastic glands (P =.005).
P53
protein were associated only with hyperplastic glands (P =.01). The different occurrence of
p53
in parathyroids adenoma and hyperplasia may enable a different management and follow-up of the patients with primary hyperparathyroidism, stratifing them into two groups. The first, with a "false" adenoma having a high risk of relapse, may necessitate exams like serum calcium levels, PTH concentrations, urinary calcium levels for 24 hours, kidney functional tests, and radiology and ultrasound every 3 to 6 months, whereas the second with "true" adenoma, at low risk of relapse, may be checked less frequently with serum calcium levels and PTH concentrations.
...
PMID:P53 as a marker of differentiation between hyperplastic and adenomatous parathyroids. 1217 Apr 54
Cerulenin, a fungal metabolite, is known to be a specific inhibitor of
fatty acid synthase
. Here we report that cerulenin is an effective inducer of apoptosis in different wild-type
p53
and mutant p53 tumor cell lines, whereas normal human keratinocytes and fibroblasts are resistant to the apoptotic effect. To get more insight into the mechanisms of how cerulenin induces apoptosis we investigated several signal transduction molecules, including
p53
, p73, p21/WAF1, Bax, cytochrome c, and caspases 3 and 9. Our data strongly indicate that mitochondria play a key role in the cerulenin-mediated pathway. Bax overexpression correlated with the extent of apoptosis and appears to be regulated in a
p53
-independent manner. The significance of the mitochondrial pathway for the cerulenin-mediated apoptosis was confirmed by the rapid mitochondrial release of cytochrome c both in wild-type
p53
and mutant cell lines. Interestingly, the rapid release of cytochrome c was not accompanied by a breakdown of the mitochondrial potential. Instead, the complete disruption of the mitochondrial function coincided with the appearance of a p18 kDa cleavage product of Bax.
...
PMID:Key role of mitochondria in cerulenin-mediated apoptosis. 1218 52
A biologically aggressive subset of human breast cancers has been demonstrated to overexpress
fatty acid synthase
(
FAS
), the key enzyme of endogenous FA biosynthesis. This breast cancer-specific activation of
FAS
-dependent lipogenesis, an anabolic-energy-storage pathway of minor importance in normal cells, would render breast cancer cells more vulnerable to anti-metabolite interventions with
FAS
as therapeutic target. Not surprisingly, pharmacological inhibitors of
FAS
have been reported to produce both cytostatic and cytotoxic effects in human breast cancer cells, as well as to suppress DNA replication. However, the signal transduction pathway(s) that link
FAS
hyperactivity and breast cancer cell growth has been unresolved. Here, we have attempted to provide a systematic approach to assess the role of
FAS
signaling on the survival and proliferation of human breast cancer cells. First, we assessed the level of
FAS
protein in a panel of human breast cancer cell lines (MCF-7, MDA-MB-231, MDA-MB-453, MDA-MB-435, ZR-75B, T47-D, BT-474, and SK-Br3).
FAS
expression was graded from ++++ (overexpression) in SK-Br3 cells to + (very low expression) in MDA-MB-231 cells. No correlation was noted between
FAS
overexpression and estrogen receptor (ER) or progesterone receptor (PR) status, whereas a positive correlation was found between high levels of
FAS
expression and the amplification and/or overexpression of HER-2/neu oncogene. Because metabolic adaptation of breast cancer cells to the ambient fatty acid concentration may be relevant to the goal of utilizing
FAS
inhibition as a chemotherapeutic target, we evaluated the effect of exogenous dietary fatty acids on the cytotoxicity resulting from the inhibition of
FAS
activity. Pharmacological inhibition of
FAS
activity by the natural antibiotic cerulenin [(2S,3R)-2,3-epoxy-4-oxo-7E,10E-dodecadienamide] resulted in a dose-dependent cytotoxicity which positively paralleled the endogenous level of
FAS
. Supraphysiological levels of exogenous oleic acid (OA), a omega-9 monounsaturated fatty acid synthesized from a primary-end product of
FAS
palmitate, significantly diminished cell toxicity caused by cerulenin. Indeed, OA exposure significantly reduced
FAS
activity and expression by 55% in
FAS
-overexpressing SK-Br3 cells. omega-3 (alpha-linolenic acid, eicosapentaenoic acid and docosahexaenoic acid) and omega-6 (linoleic acid and arachidonic acid) polyunsaturated fatty acids (PUFAs), however, were unable to rescue breast cancer cells from cerulenin-induced cytotoxicity. Pharmacological blockade of
FAS
activity in
FAS
-overexpressing SK-Br3 cells resulted in apoptosis as determined by an enzyme-linked immunosorbent assay for histone-associated DNA fragments, and confirmed by TUNEL DNA-end labeling experiments. We further characterized signaling molecules that participate in the cellular events that follow inhibition of
FAS
activity and precede apoptosis in breast cancer cells. In SK-Br3 cells, cerulenin-induced inhibition of
FAS
activity resulted in down-regulation of
p53
, and up-regulation of cyclin-dependent kinase inhibitor (CDKi) p21WAF1/CIP1. Treatment with cerulenin or a novel small-molecule inhibitor of
FAS
C75 resulted in a dramatic accumulation of CDKi p27KIP1, which was accompanied by a noteworthy translocation of p27KIP1 from cytosol to cell nuclei. Strikingly,
FAS
inhibition also caused a significant activation of the Raf-mitogen-activated protein kinase (MEK) extracellular signal-regulated kinase (ERK1/2) cell survival pathway. Interestingly, we demonstrated that inhibition of
FAS
activity increased the nuclear-to-cytoplasmic ratio of BRCA1, a breast cancer tumor suppressor protein, as well as it induced a nuclear translocalization of the anti-apoptotic nuclear transcription factor-kappaB (NF-kappaB). In conclusion, here we demonstrate that: a) breast cancer cells retain dependence on endogenous fatty acid synthesis and sensitivity to
FAS
inhibition in the presence of supraphysiological levels of dietary fatty acids, supporting the notion that
FAS
inhibition may be useful in treFAS inhibition may be useful in treating breast cancer in vivo; b) endogenous fatty acid synthesis is functional in breast cancer cells and is vital since its pharmacological inhibition is cytotoxic by promoting apoptosis, and c) specific blockade of
FAS
activity induces the accumulation, activation, and/or cellular relocalization of multiple and diverse pro- and anti-apoptotic signaling pathways, suggesting that
p53
-p21WAF1/CIP1, ERK1/2 MAPK, p27KIP1, BRCA1, and NF-kappaB play a novel role in the breast cancer cell response to a metabolic stress after perturbation of
FAS
-dependent de novo fatty acid biosynthesis.
...
PMID:Novel signaling molecules implicated in tumor-associated fatty acid synthase-dependent breast cancer cell proliferation and survival: Role of exogenous dietary fatty acids, p53-p21WAF1/CIP1, ERK1/2 MAPK, p27KIP1, BRCA1, and NF-kappaB. 1476 44
The relationship between breast cancer-associated
fatty acid synthase
(FAS; oncogenic antigen-519) and chemotherapy-induced cell damage has not been studied. We examined the ability of C75, a synthetic slow-binding inhibitor of FAS activity, to modulate the cytotoxic activity of the microtubule-interfering agent Taxol (paclitaxel) in SK-Br3, MDA-MB-231, MCF-7 and multidrug-resistant MDR-1 (P-Glycoprotein)-overexpressing MCF-7/AdrR breast cancer cells. When the combination of C75 with Taxol in either concurrent (C75 + Taxol 24 hr) or sequential (C75 24 hr --> Taxol 24 hr) schedules were tested for synergism, addition or antagonism using the isobologram and the median-effect plot analyses, co-exposure of C75 and Taxol mostly demonstrated synergistic effects, whereas sequential exposure to C75 followed by Taxol mainly showed additive or antagonistic interactions. Because the nature of the cytotoxic interactions was definitely schedule-dependent in MCF-7 cells, we next evaluated the effects of C75 on Taxol-induced apoptosis as well as Taxol-activated cell death and cell survival-signaling pathways in this breast cancer cell model. An ELISA for histone-associated DNA fragments demonstrated that C75 and Taxol co-exposure caused a synergistic enhancement of apoptotic cell death, whereas C75 pre-treatment did not enhance the apoptosis-inducing activity of Taxol. Co-exposure to C75 and Taxol induced a remarkable nuclear accumulation of activated p38 mitogen-activated protein kinase (p38 MAPK), which was accompanied by a synergistic nuclear accumulation of the
p53
tumor-suppressor protein that was phosphorylated at Ser46, a p38 MAPK-regulated pro-apoptotic modification of
p53
. As single agents, FAS blocker C75 and Taxol induced a significant stimulation of the proliferation and cell survival mitogen-activated protein kinase extracellular signal-regulated kinase (ERK1/ERK2 MAPK) activity, whereas, in combination, they interfered with ERK1/ERK2 activation. Moreover, the combined treatment of C75 and Taxol inactivated the anti-apoptotic AKT (protein kinase B) kinase more than either agent alone, as evidenced by a synergistic down-regulation of AKT phosphorylation at its activating site Ser(473) without affecting AKT protein levels. To rule out a role for non-FAS C75-mediated effects, we finally used the potent and highly sequence-specific mechanism of RNA interference (RNAi) to block FAS-dependent signaling. Importantly, SK-Br3 and multi-drug resistant MCF-7/AdrR cells transiently transfected with sequence-specific double-stranded RNA oligonucleotides targeting FAS gene demonstrated hypersensitivity to Taxol-induced apoptotic cell death. Our findings establish for the first time that FAS blockade augments the cytotoxicity of anti-mitotic drug Taxol against breast cancer cells and that this chemosensitizing effect is schedule-dependent. We suggest that the alternate activation of both the pro-apoptotic p38 MAPK-
p53
signaling and the cytoprotective MEK1/2 --> ERK1/2 cascade, as well as the inactivation of the anti-apoptotic AKT activity may explain, at least in part, the sequence-dependent enhancement of Taxol-induced cytotoxicity and apoptosis that follows inhibition of FAS activity in breast cancer cells. If chemically stable FAS inhibitors demonstrate systemic anticancer effects of FAS inhibition in vivo, these findings may render FAS as a valuable molecular target to enhance the efficacy of taxanes-based chemotherapy in human breast cancer.
...
PMID:Pharmacological and small interference RNA-mediated inhibition of breast cancer-associated fatty acid synthase (oncogenic antigen-519) synergistically enhances Taxol (paclitaxel)-induced cytotoxicity. 1565
Signet ring cell carcinoma and mucinous carcinoma are distinct subtypes of colorectal adenocarcinoma. The morphologic and molecular spectra of colorectal carcinomas with various signet ring cell components and colorectal carcinomas with various mucinous components, compared to non-mucinous adenocarcinomas, have not been examined. The study groups consisted of 39 carcinomas with various signet ring cell components ('the signet group'), 167 carcinomas with various mucinous components ('the mucinous group'), and 457 nonmucinous adenocarcinoma. We visually estimated the amounts of signet ring cell and mucinous components in tumors, and subclassified the signet and mucinous groups according to the amount of each component (< or = 19, 20-49, and > or = 50%). We sequenced BRAF and KRAS, analyzed for microsatellite instability (MSI) and 18q loss of heterozygosity (LOH), and performed immunohistochemistry for
TP53
, cyclooxygenase-2 (COX2), MLH1, O-6-methylguanine DNA methyltransferase (MGMT), p16 (CDKN2A), and
fatty acid synthase
(
FASN
). Signet ring cell carcinoma (> or = 50% signet ring cell tumors) and < or = 49% signet ring cell tumors showed similar molecular features. Except for MSI and MGMT, > or = 50% mucinous tumors and < or = 49% mucinous tumors also showed similar molecular features. BRAF mutations, MSI, and MLH1 loss were more frequent in both the signet and mucinous groups than nonmucinous carcinoma. More frequent KRAS mutations and less frequent p16 loss and
TP53
positivity were observed in the mucinous group than nonmucinous carcinoma. 18q LOH and COX2 overexpression were less common in the signet group than nonmucinous carcinoma.
FASN
levels were highest in the mucinous group, followed by nonmucinous carcinoma, and lowest in the signet group. In conclusion, a minor (< or = 49%) signet ring cell or mucinous component in colorectal carcinoma suggests molecular features similar to > or = 50% signet ring cell or mucinous carcinoma, respectively. Signet ring cell carcinoma and mucinous carcinoma are related subtypes of colorectal adenocarcinoma, but have molecular features distinct from each other.
...
PMID:Distinct molecular features of colorectal carcinoma with signet ring cell component and colorectal carcinoma with mucinous component. 1611 24
This study examined the growth inhibitory effects of the structurally related beta-diketones compounds in human cancer cells. Here, we report that 1-(2-hydroxy-5-methylphenyl)-3-phenyl-1,3-propanedione (HMDB) induces growth inhibition of human cancer cells and induction of apoptosis in A431 cells through modulation of mitochondrial functions regulated by reactive oxygen species (ROS). ROS generation occurs in the early stages of HMDB-induced apoptosis, preceding cytochrome c release, caspase activation, and DNA fragmentation. The changes occurred after single breaks in DNA were detected, suggesting that HMDB induced irreparable DNA damage, which in turn triggered the process of apoptosis. Up-regulation of Bad and p21; down-regulation of Bcl-2, Bcl-XL, Bid,
p53
, and
fatty acid synthase
; and cleavage of Bax were found in HMDB-treated A431 cells. Glutathione and N-acetylcysteine (NAC) suppress HMDB-induced apoptosis. HMDB markedly enhanced growth arrest DNA damage inducible gene 153 (GADD153) mRNA and protein in a time- and concentration-dependent manner. NAC prevented up-regulation of GADD153 mRNA expression caused by HMDB. These findings suggest that HMDB creates an oxidative cellular environment that induces DNA damage and GADD153 gene activation, which in turn helps trigger apoptosis in A431 cells.
...
PMID: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. 1627
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