Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.56 (caspase-3)
 35,750 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Inhibitors of the epidermal growth factor receptor (EGFR) have generated considerable hope for cancer treatment, specifically for lung and breast cancers. Therefore, identification of a natural, nontoxic agent(s) as an inhibitor of EGFR is of considerable importance. Delphinidin, an anthocyanidin present in pigmented fruits and vegetables, possesses potent antioxidant and antiproliferative properties. In our study, employing EGFR positive breast cancer AU-565 cells and immortalized MCF-10A cells, we evaluated the effect of delphinidin on EGFR and its downstream signaling pathways. Delphinidin (5-40 microM; 3 hr) treatment of both AU-565 cells and MCF-10A cells inhibited the (i) phosphorylation of EGFR, (ii) activation of PI3K, (iii) phosphorylation of AKT and MAPK. Further, delphinidin treatment of AU-565 cells inhibited EGF-induced autophosphorylation of EGFR, AKT and MAPK, activation of PI3K and cell invasion. We then compared the growth inhibitory effects of delphinidin (5-40 microM; 48 hr), and found that it resulted in a decrease in cell growth of AU-565 and MCF-10A cells but had only minimal effects on normal mammary epithelial 184A1 cells. Treatment of AU-565 cells with delphinidin resulted in (i) induction of apoptosis, (ii) cleavage of PARP protein, (iii) activation of caspase-3 and (iv) downregulation of Bcl-2 with an increase in the expression of Bax. In summary, our study identifies a naturally occurring dietary agent delphinidin as an effective inhibitor of EGFR signaling in breast cancer cells. We suggest that delphinidin could be developed as an agent for the management of EGFR positive human cancers.
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PMID:Inhibition of epidermal growth factor receptor signaling pathway by delphinidin, an anthocyanidin in pigmented fruits and vegetables. 1862 29

Little is known about the preanalytical fluctuations of phosphoproteins during tissue procurement for molecular profiling. This information is crucial to establish guidelines for the reliable measurement of these analytes. To develop phosphoprotein profiles of tissue subjected to the trauma of excision, we measured the fidelity of 53 signal pathway phosphoproteins over time in tissue specimens procured in a community clinical practice. This information provides strategies for potential surrogate markers of stability and the design of phosphoprotein preservative/fixation solutions. Eleven different specimen collection time course experiments revealed augmentation (+/-20% from the time 0 sample) of signal pathway phosphoprotein levels as well as decreases over time independent of tissue type, post-translational modification, and protein subcellular location (tissues included breast, colon, lung, ovary, and uterus (endometrium/myometrium) and metastatic melanoma). Comparison across tissue specimens showed an >20% decrease of protein kinase B (AKT) Ser-473 (p < 0.002) and myristoylated alanine-rich C-kinase substrate protein Ser-152/156 (p < 0.0001) within the first 90-min postexcision. Proteins in apoptotic (cleaved caspase-3 Asp-175 (p < 0.001)), proliferation/survival/hypoxia (IRS-1 Ser-612 (p < 0.0003), AMP-activated protein kinase beta Ser-108 (p < 0.005), ERK Thr-202/Tyr-204 (p < 0.003), and GSK3alphabeta Ser-21/9 (p < 0.01)), and transcription factor pathways (STAT1 Tyr-701 (p < 0.005) and cAMP response element-binding protein Ser-133 (p < 0.01)) showed >20% increases within 90-min postprocurement. Endothelial nitric-oxide synthase Ser-1177 did not change over the time period evaluated with breast or leiomyoma tissue. Treatment with phosphatase or kinase inhibitors alone revealed that tissue kinase pathways are active ex vivo. Combinations of kinase and phosphatase inhibitors appeared to stabilize proteins that exhibited increases in the presence of phosphatase inhibitors alone (ATF-2 Thr-71, SAPK/JNK Thr-183/Tyr-185, STAT1 Tyr-701, JAK1 Tyr-1022/1023, and PAK1/PAK2 Ser-199/204/192/197). This time course study 1) establishes the dynamic nature of specific phosphoproteins in excised tissue, 2) demonstrates augmented phosphorylation in the presence of phosphatase inhibitors, 3) shows that kinase inhibitors block the upsurge in phosphorylation of phosphoproteins, 4) provides a rational strategy for room temperature preservation of proteins, and 5) constitutes a foundation for developing evidence-based tissue procurement guidelines.
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PMID:A portrait of tissue phosphoprotein stability in the clinical tissue procurement process. 1866 11

Cholesterol-rich diets are known to cause hepatic apoptosis, which has been associated with the pathogenesis of systemic lupus erythematosus (SLE). However, the mechanisms and treatments for hepatic apoptosis in SLE are poorly understood. To clarify the effects of taurine on hepatic apoptosis in SLE, NZB/W F1 mice received control, cholesterol, and cholesterol/taurine diets. Significant reductions of caspase-3 activity, TUNEL-positive cells, and Fas- and mitochondrial- dependent apoptosis were detected in liver from the cholesterol/taurine group as compared to the cholesterol group. Moreover, significant increases of phosphorylated AKT, NF-kappaB (p65), and ERK1/2 proteins were detected in liver from the cholesterol/taurine group as compared to the cholesterol group. In contrast, a significant reduction of phosphorylated p38 protein was observed in the cholesterol/taurine group. These experimental results demonstrated positive effects of taurine against hepatic apoptosis in NZB/W F1 mice fed a high-cholesterol diet and suggested the therapeutic potential of taurine in SLE.
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PMID:Treatment with taurine attenuates hepatic apoptosis in NZB/W F1 mice fed with a high-cholesterol diet. 1881 57

We have identified a natural compound that activates apoptosis of epithelial cancer cells through activation of tumor necrosis factor-alpha (TNF-alpha), TNF receptor (TNFR)-associated death domain (TRADD), and caspases. The molecule 1-hydroxy-5,7-dimethoxy-2-naphthalene-carboxaldehyde (HDNC, marmelin) was isolated and characterized from ethyl acetate fraction of extracts of Aegle marmelos. HDNC treatment inhibited the growth of HCT-116 colon cancer tumor xenografts in vivo. Immunostaining for CD31 showed that there was a significant reduction in microvessels in the HDNC-treated animals, coupled with decreased cyclooxygenase-2, interleukin-8, and vascular endothelial growth factor mRNA. Using hexoseaminidase assay, we determined that HDNC inhibits proliferation of HCT-116 colon and HEp-2 alveolar epithelial carcinoma cells. Furthermore, the cancer cells showed increased levels of activated caspase-3 and induced G(1) cell cycle arrest, which was suppressed by caspase-3 inhibitors. HDNC induced TNF-alpha, TNFR1, and TRADD mRNA and protein expression. Moreover, caspase-8 and Bid activation, and cytochrome c release, were observed, suggesting the existence of a cross-talk between death receptor and the mitochondrial pathways. HDNC inhibited AKT and extracellular signal-regulated kinase phosphorylation both in cells in culture and in tumor xenografts. In addition, electrophoretic mobility shift assay and luciferase reporter assays showed that HDNC significantly suppressed TNF-alpha-mediated activation and translocation of nuclear factor-kappaB (NF-kappaB). This was further confirmed by Western blot analysis of nuclear extracts wherein levels of RelA, the p65 component of NF-kappaB, were significantly less in cells treated with HDNC. Together, the data suggest that the novel compound HDNC (marmelin) is a potent anticancer agent that induces apoptosis during G(1) phase of the cell cycle and could be a potential chemotherapeutic candidate.
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PMID:Activation of apoptosis by 1-hydroxy-5,7-dimethoxy-2-naphthalene-carboxaldehyde, a novel compound from Aegle marmelos. 1892 33

Inactivation and silencing of PTEN have been observed in multiple cancers, including follicular thyroid carcinoma. PTEN (phosphatase and tensin homologue deleted from chromosome 10) functions as a tumour suppressor by opposing the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signalling pathway. Despite correlative data, how deregulated PTEN signalling leads to thyroid carcinogenesis is not known. Mice harbouring a dominant-negative mutant thyroid hormone receptor beta (TRbeta(PV/PV) mice) spontaneously develop follicular thyroid carcinoma and distant metastases similar to human cancer. To elucidate the role of PTEN in thyroid carcinogenesis, we generated TRbeta(PV/PV) mice haploinsufficient for Pten (TRbeta(PV/PV)Pten(+/-) mouse). PTEN deficiency accelerated the progression of thyroid tumour and increased the occurrence of metastasis spread to the lung in TRbeta(PV/PV)Pten(+/-) mice, thereby significantly reducing their survival as compared with TRbeta(PV/PV)Pten(+/+) mice. AKT activation was further increased by two-fold in TRbeta(PV/PV)Pten(+/-) mice thyroids, leading to increased activity of the downstream mammalian target of rapamycin (mTOR)-p70S6K signalling and decreased activity of the forkhead family member FOXO3a. Consistently, cyclin D1 expression was increased. Apoptosis was decreased as indicated by increased expression of nuclear factor-kappaB (NF-kappaB) and decreased caspase-3 activity in the thyroids of TRbeta(PV/PV)Pten(+/-) mice. Our results indicate that PTEN deficiency resulted in increased cell proliferation and survival in the thyroids of TRbeta(PV/PV)Pten(+/-) mice. Altogether, our study provides direct evidence to indicate that in vivo, PTEN is a critical regulator in the follicular thyroid cancer progression and invasiveness.
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PMID:PTEN deficiency accelerates tumour progression in a mouse model of thyroid cancer. 1899 18

Emerging evidence indicates that mineralocorticoid receptor (MR) blockade reduces the risk of cardiovascular events beyond those predicted by its blood pressure-lowering actions; however, the underlying mechanisms remain unclear. To investigate whether protection elicited by MR blockade is through attenuation of vascular apoptosis and injury, independently of blood pressure lowering, we administered a low dose of the MR antagonist spironolactone or vehicle for 21 days to hypertensive transgenic Ren2 rats with elevated plasma aldosterone levels. Although Ren2 rats developed higher systolic blood pressures compared with Sprague-Dawley littermates, low-dose spironolactone treatment did not reduce systolic blood pressure compared with untreated Ren2 rats. Ren2 rats exhibited vascular injury as evidenced by increased apoptosis, hemidesmosome-like structure loss, mitochondrial abnormalities, and lipid accumulation compared with Sprague-Dawley rats, and these abnormalities were attenuated by MR antagonism. Protein kinase B activation is critical to vascular homeostasis via regulation of cell survival and expression of apoptotic genes. Protein kinase B serine(473) phosphorylation was impaired in Ren2 aortas and restored with MR antagonism. In vivo MR antagonist treatment promoted antiapoptotic effects by increasing phosphorylation of BAD serine(136) and expression of Bcl-2 and Bcl-xL, decreasing cytochrome c release and BAD expression, and suppressing caspase-3 activation. Furthermore, MR antagonism substantially reduced the elevated NADPH oxidase activity and lipid peroxidation, expression of angiotensin II, angiotensin type 1 receptor, and MR in Ren2 vasculature. These results demonstrate that MR antagonism protects the vasculature from aldosterone-induced vascular apoptosis and structural injury via rescuing protein kinase B activation, independent of blood pressure effects.
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PMID:Mineralocorticoid receptor antagonism attenuates vascular apoptosis and injury via rescuing protein kinase B activation. 1911 43

The present study was undertaken to examine whether lycopene is able to counteract 7-ketocholesterol (7-KC)-induced oxidative stress and apoptosis in human macrophages. Human THP-1 macrophages were exposed to 7-KC (10-25 microM) alone and in combination with lycopene (0.5-2 microM), and we monitored changes in cell oxidative status [reactive oxygen species (ROS) production, NOX-4, hsp70 and hsp90 expressions, 8-OHdG formation] and in cell proliferation and apoptosis. After 24 h of treatment, lycopene significantly reduced the increase in ROS production and in 8-OHdG formation induced by the oxysterol in a dose-dependent manner. Moreover, the carotenoid strongly prevented the increase of NOX-4, hsp70 and hsp90 expressions as well as the phosphorylation of the redox-sensitive p38, JNK and ERK1/2 induced by the oxysterol. The attenuation of 7-KC-induced oxidative stress by lycopene coincided with a normalization of cell growth in human macrophages. Lycopene prevented the arrest in G0/G1 phase of cell cycle induced by the oxysterol and counteracted the increased expression of p53 and p21. Concomitantly, it inhibited 7-KC-induced apoptosis, by limiting caspase-3 activation and the modulatory effects of 7-KC on AKT, Bcl-2, Bcl-xL and Bax. Comparing the effects of lycopene, beta-carotene and (5Z)-lycopene on ROS production, cell growth and apoptosis show that lycopene and its isomer were more effective than beta-carotene in counteracting the dangerous effects of 7-KC in human macrophages. Our study suggests that lycopene may act as a potential antiatherogenic agent by preventing 7-KC-induced oxidative stress and apoptosis in human macrophages.
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PMID:Lycopene prevents 7-ketocholesterol-induced oxidative stress, cell cycle arrest and apoptosis in human macrophages. 1915 29

Cetuximab (Erbitux) is an anti-epidermal growth factor receptor (EGFR) monoclonal antibody whose activity is related to the inhibition of EGFR downstream signaling pathways. P53 and phosphatase and tensin homologue deleted on chromosome 10 (PTEN) have been reported to control the functionality of PI3K/AKT signaling. In this study we evaluated whether reintroducing P53 using non-viral gene transfer enhances PTEN-mediated inhibition of PI3K/AKT signaling by cetuximab in PC3 prostate adenocarcinoma cell line bearing p53 and pten mutations. Signaling phosphoproteins expression was analyzed using Bio-Plex phosphoprotein array and western blot. Apoptosis induction was evaluated from BAX expression, caspase-3 activation and DNA fragmentation analyses. The results presented show that p53 and pten gene transfer additionally mediated cell growth inhibition and apoptosis induction by restoral of signaling functionality, which enabled the control of PI3K/AKT and MAPKinase signaling pathways by cetuximab in PC3 cells. These results highlight the interest of the analysis of signaling phosphoproteins expression as molecular predictive markers for response to cetuximab and show that p53 and pten mutations could be key determinants of cell response to cetuximab through the functional impact of these mutations on cell signaling.
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PMID:P53 and PTEN expression contribute to the inhibition of EGFR downstream signaling pathway by cetuximab. 1916 35

Gonadotropin-releasing hormone-I (GnRH-I) is known to directly regulate prostate cancer cell proliferation. However, the role of GnRH-II in prostate cancer is unclear. Here, we investigated the effect of the GnRH-II antagonist trptorelix-1 (Trp-1) on growth of PC3 prostate cancer cells. Trp-1 induced growth inhibition of PC3 cells in vitro and inhibited growth of PC3 cells xenografted into nude mice. FITC-N3, an FITC-conjugated Trp-1 analogue, was largely present in the mitochondria of prostate cancer cells, but not in other cells that are not derived from the prostate. Trp-1-induced PC3 growth inhibition was associated with decreased mitochondrial membrane potential and increased levels of mitochondrial and cytosolic reactive oxygen species (ROS). Growth inhibition was partially prevented by cotreating cells with N-acetyl cysteine, an antioxidant. Cytochrome c release and caspase-3 activation were not detected in Trp-1-treated cells. However, Trp-1 induced autophagosome formation, as seen by increased LysoTracker staining and recruitment of microtubule-associated protein 1 light chain 3 to these new lysosomal compartments. Trp-1-induced autophagy was accompanied by decreased AKT phosphorylation and increased c-Jun NH(2) terminal kinase phosphorylation, two events known to be linked to autophagy. Taken together, these data suggest that Trp-1 directly induces mitochondrial dysfunction and ROS increase, leading to autophagy of prostate cancer cells. GnRH-II antagonists may hold promise in the treatment of prostate cancer.
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PMID:A gonadotropin-releasing hormone-II antagonist induces autophagy of prostate cancer cells. 1917 90

The flavonol quercetin, especially abundant in apple, wine, and onions, is reported to have anti-proliferative effects in many cancer cell lines. Antioxidant or pro-oxidant activities and kinase inhibition have been proposed as molecular mechanisms for these effects. In addition, an estrogenic activity has been observed but, at the present, it is poorly understood whether this latter activity plays a role in the quercetin-induced anti-proliferative effects. Here, we studied the molecular mechanisms of quercetin committed to the generation of an apoptotic cascade in cancer cells devoid or containing transfected estrogen receptor alpha (ERalpha; i.e., human cervix epitheloid carcinoma HeLa cells). Although none of tested quercetin concentrations increase reactive oxygen species (ROS) generation in HeLa cells, quercetin stimulation prevents the H(2)O(2)-induced ROS production both in the presence and in the absence of ERalpha. However, this flavonoid induces the activation of p38/MAPK, leading to the pro-apoptotic caspase-3 activation and to the poly(ADP-ribose) polymerase cleavage only in the presence of ERalpha. Notably, no down-regulation of survival kinases (i.e., AKT and ERK) was reported. Taken together, these findings suggest that quercetin results in HeLa cell death through an ERalpha-dependent mechanism involving caspase- and p38 kinase activation. These findings indicate new potential chemopreventive actions of flavonoids on cancer growth.
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PMID:Quercetin-induced apoptotic cascade in cancer cells: antioxidant versus estrogen receptor alpha-dependent mechanisms. 1919 71


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