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1.
Glioblastoma is the deadliest brain tumor in humans. Current therapies are mostly ineffective and new agents need to be explored
for controlling this devastating disease. Inositol hexaphosphate (IP6) is a phytochemical that is widely found in corns, cereals,
nuts, and high fiber-content foods. Previous studies demonstrated anti-cancer properties of IP6 in several in vitro and in
vivo tumor models. However, therapeutic efficacy of IP6 has not yet been evaluated in glioblastoma. Here, we explored the
molecular mechanism of action of IP6 in human malignant glioblastoma T98G cells. The viability of T98G cells decreased following
treatment with increasing doses of IP6. T98G cells exposed to 0.25, 0.5, and 1 mM IP6 for 24 h showed morphological and biochemical
features of apoptosis. Western blotting indicated changes in expression of Bax and Bcl-2 proteins resulting in an increase
in Bax:Bcl-2 ratio and upregulation of cytosolic levels of cytochrome c and Smac/Diablo, suggesting involvement of mitochondria-dependent
caspase cascade in apoptosis. IP6 downregulated cell survival factors such as baculovirus inhibitor-of-apoptosis repeat containing-2
(BIRC-2) protein and telomerase to promote apoptosis. Upregulation of calpain and caspase-9 occurred in course of apoptosis.
Increased activities of calpain and caspase-3 cleaved 270 kD α-spectrin at specific sites generating 145 kD spectrin break
down product (SBDP) and 120 kD SBDP, respectively. Increased caspase-3 activity also cleaved inhibitor of caspase-3-activated
DNase and poly(ADP-ribose) polymerase. Collectively, our results demonstrated that IP6 down regulated the survival factors
BIRC-2 and telomerase and upregulated calpain and caspase-3 activities for apoptosis in T98G cells.
Special issue in honor of Naren Banik. 相似文献
2.
3.
Glioblastoma shows poor response to current therapies and warrants new therapeutic strategies. We examined the efficacy of
combination of valproic acid (VPA) and taxol (TX) or nanotaxol (NTX) in human glioblastoma LN18 and T98G cell lines. Cell
differentiation was manifested in changes in morphological features and biochemical markers. Cell growth was controlled with
down regulation of vascular endothelial growth factor (VEGF), epidermal growth factor receptor (EGFR), nuclear factor-kappa
B (NF-κB), phospho-Akt (p-Akt), and multi-drug resistance (MDR) marker, indicating suppression of angiogenic, survival, and
multi-drug resistance pathways. Cell cycle analysis showed that combination therapy (VPA and TX or NTX) increased the apoptotic
sub G1 population and apoptosis was further confirmed by Annexin V-FITC/PI binding assay and scanning electron microscopy.
Combination therapy caused activation of caspase-8 and cleavage of Bid to tBid and increased Bax:Bcl-2 ratio and mitochondrial
release of cytochrome c and apoptosis-inducing factor (AIF). Upregulation of calpain and caspases (caspase-9 and caspase-3)
and substrate degradation were also detected in course of apoptosis. The combination of VPA and NTX most effectively controlled
the growth of LN18 and T98G cells. Therefore, this combination of drugs can be used as an effective treatment for controlling
growth of human glioblastoma cells. 相似文献
4.
Glioblastoma is the most malignant human brain tumor that shows poor response to existing therapeutic agents. Search continues
for an effective therapy for controlling this deadliest brain tumor. Curcumin (CCM), a polyphenolic compound from Curcuma longa, possesses anti-cancer properties in both in vitro and in vivo. In the present investigation, we evaluated the therapeutic
efficacy of CCM against human malignant glioblastoma U87MG cells. Trypan blue dye exclusion test showed decreased viability
of U87MG cells with increasing dose of CCM. Wright staining and ApopTag assay, respectively, showed the morphological and
biochemical features of apoptosis in U87MG cells treated with 25 μM and 50 μM of CCM for 24 h. Western blotting showed activation
of caspase-8, cleavage of Bid to tBid, increase in Bax:Bcl-2 ratio, and release of cytochrome c from mitochondria followed by activation of caspase-9 and caspase-3 for apoptosis. Also, CCM treatments increased cytosolic
level of Smac/Diablo to suppress the inhibitor-of-apoptosis proteins and down regulated anti-apoptotic nuclear factor kappa
B (NFκB), favoring the apoptosis. Increased activities of calpain and caspase-3 cleaved 270 kDa α-spectrin at specific sites
generating 145 kDa spectrin break down product (SBDP) and 120 kDa SBDP, respectively, leading to apoptosis in U87MG cells.
Results show that CCM is an effective therapeutic agent for suppression of anti-apoptotic factors and activation of calpain
and caspase proteolytic cascades for apoptosis in human malignant glioblastoma cells.
Special issue in honor of Naren Banik. 相似文献
5.
Surajit Karmakar Subhasree Roy Choudhury Naren L. Banik 《Biochemical and biophysical research communications》2009,388(4):705-1117
Neuroblastoma is the most common extracranial solid tumor in infants and young children. Current treatments are not always effective and new therapies are needed. We examined efficacy of combination of the small molecule Bcl-2 inhibitor HA14-1 (HA) and the dietary isoflavonoid apigenin (APG) in human malignant neuroblastoma cells. Dose-response studies indicated that treatment with HA and APG for 24 h synergistically reduced cell viability in human malignant neuroblastoma SK-N-DZ, SH-SY5Y, and IMR32 cells. For further studies, we selected SK-N-DZ cells that showed the highest sensitivity following treatment with 2.5 μM HA, 100 μM APG, or combination (2.5 μM HA + 100 μM APG). Wright staining showed increase in morphological features of apoptosis. Cell cycle distribution and Annexin V assay showed that combination therapy caused more apoptosis than either treatment alone. Western blotting revealed that combination therapy downregulated angiogenic factors and also induced extrinsic pathway of apoptosis with activation of caspase-8 for Bid cleavage to tBid. Alterations in Bax and Bcl-2 levels resulted in an increase in Bax:Bcl-2 ratio to activate intrinsic pathway of apoptosis with mitochondrial release of cytochrome c into the cytosol and activation of proteases. Increases in calpain and caspase-3 activities generated 145 kD spectrin break down product (SBDP) and 120 kD SBDP, respectively. Results showed that combination of HA and APG could be used for downregulation of angiogenic factors and activation of extrinsic and intrinsic pathways of apoptosis in malignant neuroblastoma cells. 相似文献
6.
7.
Garlic compounds induced calpain and intrinsic caspase cascade for apoptosis in human malignant neuroblastoma SH-SY5Y cells 总被引:12,自引:1,他引:11
Karmakar S Banik NL Patel SJ Ray SK 《Apoptosis : an international journal on programmed cell death》2007,12(4):671-684
Malignant (N-type) neuroblastoma continues to defy current chemotherapeutic regimens. We tested the garlic compounds diallyl
sulfide (DAS) and diallyl disulfide (DADS) for induction of apoptosis in human malignant neuroblastoma SH-SY5Y cells. Viability
of human primary neurons was unaffected after 24 h treatment with 50 and 100 μM DAS and 50 μM DADS but slightly affected with
100 μM DADS. Treatment with 50 and 100 μM DAS or DADS significantly decreased viability in SH-SY5Y cells. Wright staining
showed morphological features of apoptosis in SH-SY5Y cells treated with 50 and 100 μM DAS or DADS for 24 h. ApopTag assay
demonstrated DNA fragmentation in apoptotic cells. Apoptosis was associated with an increase in [Ca2+]i, increase in Bax:Bcl-2 ratio, mitochondrial release of cytochrome c, increase in cytosolic Smac/Diablo, and down regulation of inhibitor-of-apoptosis proteins and nuclear factor kappa B (NFκB).
Activation of caspase-9 and caspase-3 indicated involvement of intrinsic pathway of apoptosis. Calpain and caspase-3 activities
produced 145 kD spectrin break down product (SBDP) and 120 kD SBDP, respectively. Also, caspase-3 activity cleaved inhibitor
of caspase-activated DNase (ICAD). Results strongly suggested that the garlic compounds DAS and DADS suppressed anti-apoptotic
factors and activated calpain and intrinsic caspase cascade for apoptosis in SH-SY5Y cells. 相似文献
8.
The anti-neoplastic drug taxol binds to β-tubulin to prevent tumor cell division, promoting cell death. However, high dose
taxol treatment may induce cell death in normal cells too. The anti-apoptotic molecule Bcl-2 is upregulated in many cancer
cells to protect them from apoptosis. In the current study, we knocked down Bcl-2 expression using cognate siRNA during low-dose
taxol treatment to induce apoptosis in two human glioblastoma U138MG and U251MG cell lines. The cells were treated with either
100 nM taxol or 100 nM Bcl-2 siRNA or both for 72 h. Immunofluorescent stainings for calpain and active caspase-3 showed increases
in expression and co-localization of these proteases in apoptotic cells. Fluorometric assays demonstrated increases in intracellular
free [Ca2+], calpain, and caspase-3 indicating augmentation of apoptosis. Western blotting demonstrated dramatic increases in the levels
of Bax, Bak, tBid, active caspases, DNA fragmentation factor-40 (DFF40), cleaved fragments of lamin, fodrin, and poly(ADP-ribose)
polymerase (PARP) during apoptosis. The events related to apoptosis were prominent more in combination therapy than in either
treatment alone. Our current study demonstrated that Bcl-2 siRNA significantly augmented taxol mediated apoptosis in different
human glioblastoma cells through induction of calpain and caspase proteolytic activities. Thus, combination of taxol and Bcl-2
siRNA offers a novel therapeutic strategy for controlling the malignant growth of human glioblastoma cells.
Special issue article in honor of Dr. George DeVries. 相似文献
9.
10.
Glioblastoma, the deadliest brain tumor in humans, responds poorly to conventional chemotherapeutic agents because of existence of highly chemoresistant human brain tumor stem cells (HBTSC). An effective therapeutic strategy is urgently needed to target HBTSC as well as other glioblastoma cells. We explored synergistic efficacy of a low dose of curcumin (CCM) and a low dose of paclitaxel (PTX) in HBTSC and human glioblastoma LN18 (p53 mutant and PTEN proficient) and U138MG (p53 mutant and PTEN mutant) cells. The highest expression of the cancer stem cell markers aldehyde dehydrogenase 1 (ALDH1) and CD133 occurred in HBTSC when compared with LN18 and U138MG cells. Combination of 20 μM CCM and 10 nM PTX worked synergistically and more effectively than either drug alone in decreasing viability in all cells. Combination of CCM and PTX was highly effective in inducing both morphological and biochemical features of apoptosis. Apoptosis required activation of caspase-8, cleavage of Bid to tBid, increase in Bax:Bcl-2 ratio, and mitochondrial release of cytochrome c, Smac, and apoptosis-inducing factor (AIF). Phosphorylation of Bcl-2 following combination therapy appeared to promote Bax homodimerization and mitochondrial release of pro-apoptotic factors into the cytosol. Increases in activities of cysteine proteases confirmed the completion of apoptotic process. Combination therapy inhibited invasion of cells, reduced expression of survival and proliferation factors and also angiogenic factors, and prevented HBTSC, LN18, and U138MG cells from promoting network formation. Collectively, the combination of CCM and PTX worked as a promising therapy for controlling the growth of HBTSC and other glioblastoma cells. 相似文献
11.
Glioblastoma patients receive anti-inflammatory agent for alleviation of vasogenic edema and pain prior to surgery, radiotherapy,
and chemotherapy. Oxidative stress is an important mechanism of action of some chemotherapeutic agents in the treatment of
glioblastoma. So, we examined the modulatory effects of methylprednisolone (MP, a steroidal anti-inflammatory agent) and indomethacin
(IM, a non-steroidal anti-inflammatory agent) on apoptosis in rat C6 glioblastoma cells following oxidative stress with hydrogen
peroxide (H2O2). Exposure of C6 cells to 1 mM H2O2 for 24 h caused significant amounts of morphological and biochemical features of apoptosis. Expressions of Bax and Bcl-2
at mRNA and protein levels were altered resulting in an increase in Bax : Bcl-2 ratio in apoptotic cells, which also exhibited
overexpression of 80 kDa calpain and an increase in calpain-cleaved 145 kDa α-spectrin breakdown product. Immunofluorescent
and propidium iodide labeling detected caspase-3-p20 fragment in apoptotic cells, indicating activation of caspase-3 as well.
Treatment of cells with 1 μM MP or 10 μM IM alone did not induce apoptosis. Pretreatment (1 h) with either 1 μM MP or 10 μM
IM significantly inhibited H2O2 mediated apoptosis in C6 cells. Thus, pretreatment of glioblastoma with an anti-inflammatory agent, either steroidal or non-steroidal,
may compromise the action of a chemotherapeutic agent that mediates therapeutic action via oxidative stress. 相似文献
12.
Juan A. Martinez Zhiqun Zhang Stanislav I. Svetlov Ronald L. Hayes Kevin K. Wang Stephen F. Larner 《Apoptosis : an international journal on programmed cell death》2010,15(12):1480-1493
Neuronal cell death after traumatic brain injury, Alzheimer’s disease and ischemic stroke may in part be mediated through
endoplasmic reticulum (ER) stress and unfolded protein response (UPR). UPR results in induction of molecular chaperone GRP78
and the ER-resident caspase-12, whose activation has been proposed to be mediated by calpain and caspase processing, although
their relative contribution remains unclear. In this study we induced ER stress with thapsigargin (TG), and determined the
activation profile of calpain-2, caspase-3, caspase-7, and caspase-12 by analyses of protein levels, corresponding substrates
and breakdown products (BDP). Specific calpain and caspase activity was assessed by analysis of αII-spectrin BDP of 145 kDa
(SBDP145), BDP of 150 kDa (SBDP150) and BDP of 120 kDa (SBDP120). Decrease in pro-calpain-2 protein and increased SBDP145
levels by 3 h after TG treatment indicated early calpain activity. Active caspase-7 (p20) increase occurred after 8 h, followed
by concomitant up-regulation of active caspase-3 and SBDP120 after 24 h. In vitro digestion experiments supported that SBDP120
was exclusively generated by active caspase-3 and validated that kinectin and co-chaperone p23 were calpain and caspase-7
substrates, respectively. Pro-caspase-12 protein processing by the specific action of calpain and caspase-3/7 was observed
in a time-dependent manner. N-terminal pro-domain processing of pro-caspase-12 by calpain generated a 38 kDa fragment, while
caspase-3/7 generated a 35 kDa fragment. Antibody developed specifically against the caspase-3/7 C-terminal cleavage site
D341 detected the presence of large subunit (p20) containing 23 kDa fragment that increased after 24 h of TG treatment. Significant
caspase-12 enzyme activity was only detected after 24 h of TG treatment and was completely inhibited by caspase 3/7 inhibitor
DEVD-fmk and partially by calpain inhibitor SNJ-1945. ER-stress-induced cell death pathway in TG-treated PC12 cells was characterized
by up-regulation of GRP-78 and processing and activation of caspase-12 by the orchestrated proteolytic activity of calpain-2
and caspase-3/7. 相似文献
13.
Although resveratrol, an active ingredient derived from grapes and red wine, possesses chemopreventive properties against
several cancers, the molecular mechanisms by which it inhibits cell growth and induces apoptosis have not been clearly understood.
Here, we examined the molecular mechanisms of resveratrol and its interactive effects with TRAIL on apoptosis in prostate
cancer PC-3 and DU-145 cells. Resveratrol inhibited cell viability and colony formation, and induced apoptosis in prostate
cancer cells. Resveratrol downregulated the expression of Bcl-2, Bcl-XL and survivin and upregulated the expression of Bax, Bak, PUMA, Noxa, and Bim, and death receptors (TRAIL-R1/DR4 and TRAIL-R2/DR5).
Treatment of prostate cancer cells with resveratrol resulted in generation of reactive oxygen species (ROS), translocation
of Bax to mitochondria and subsequent drop in mitochondrial membrane potential, release of mitochondrial proteins (cytochrome
c, Smac/DIABLO, and AIF) to cytosol, activation of effector caspase-3 and caspase-9, and induction of apoptosis. Resveratrol-induced
ROS production, caspase-3 activity and apoptosis were inhibited by N-acetylcysteine. Bax was a major proapoptotic gene mediating the effects of resveratrol as Bax siRNA inhibited resveratrol-induced
apoptosis. Resveratrol enhanced the apoptosis-inducing potential of TRAIL, and these effects were inhibited by either dominant
negative FADD or caspase-8 siRNA. The combination of resveratrol and TRAIL enhanced the mitochondrial dysfunctions during
apoptosis. These properties of resveratrol strongly suggest that it could be used either alone or in combination with TRAIL
for the prevention and/or treatment of prostate cancer. 相似文献
14.
Haque A Das A Hajiaghamohseni LM Younger A Banik NL Ray SK 《Cancer immunology, immunotherapy : CII》2007,56(5):615-625
Glioblastoma is the most common and highly malignant brain tumor. It is also one among the most therapy-resistant human neoplasias. Patients die within a year of diagnosis despite the use of available treatment strategies such as surgery, radiotherapy, and chemotherapy. Thus, there is a critical need to find a novel therapeutic strategy for treating this disease. Here, we have investigated the molecular mechanisms for induction of apoptosis as well as for activation of immune components in human malignant glioblastoma T98G and U87MG cells following treatment with all-trans retinoic acid (ATRA) plus interferon-gamma (IFN-gamma). Treatment of glioblastoma cells with ATRA alone prevented cell proliferation and induced astrocytic differentiation, while IFN-gamma alone induced apoptosis and modulated expression of human leukocyte antigen (HLA) class II molecules such as HLA-DRalpha, HLA-DR complex, invariant chain (Ii), HLA-DM (an important catalyst of the class II-peptide loading), and gamma interferon-inducible lysosomal thiol-reductase (GILT). Interestingly, both T98G and U87MG cells showed more increase in apoptosis with expression of the HLA class II components for an effective immune response following treatment with ATRA plus IFN-gamma than with IFN-gamma alone. Apoptotic mode of cell death was confirmed morphologically by Wright staining and biochemically by measuring an increase in caspase-3 activity. While conversion of tumor cells into HLA class II+/Ii- cells by stimulation with the helper CD4+ T cells is thought to be challenging, this study reports for the first time that treatment of glioblastoma cells with ATRA plus IFN-gamma can simultaneously enhance apoptosis and expression of the HLA class II immune components with a marked suppression of Ii expression. Taken together, this study suggests that induction of apoptosis and immune components of the HLA class II pathway by ATRA plus IFN-gamma may be a promising chemoimmunotherapeutic strategy for treatment of human malignant glioblastoma. 相似文献
15.
Upon apoptosis induction, the proapoptotic protein Bax is translocated from the cytosol to mitochondria, where it promotes release of cytochrome c, a caspase-activating protein. However, the molecular mechanisms by which Bax triggers cytochrome c release are unknown. Here we report that before the initiation of apoptotic execution by etoposide or staurosporin, an active calpain activity cleaves Bax at its N-terminus, generating a potent proapoptotic 18-kDa fragment (Bax/p18). Both the calpain-mediated Bax cleavage activity and the Bax/p18 fragment were found in the mitochondrial membrane-enriched fraction. Cleavage of Bax was followed by release of mitochondrial cytochrome c, activation of caspase-3, cleavage of poly(ADP-ribose) polymerase, and fragmentation of DNA. Unlike the full-length Bax, Bax/p18 did not interact with the antiapoptotic Bcl-2 protein in the mitochondrial fraction of drug-treated cells. Pretreatment with a specific calpain inhibitor calpeptin inhibited etoposide-induced calpain activation, Bax cleavage, cytochrome c release, and caspase-3 activation. In contrast, transfection of a cloned Bax/p18 cDNA into multiple human cancer cell lines targeted Bax/p18 to mitochondria, which was accompanied by release of cytochrome c and induction of caspase-3-mediated apoptosis that was not blocked by overexpression of Bcl-2 protein. Therefore, Bax/p18 has a cytochrome c-releasing activity that promotes cell death independent of Bcl-2. Finally, Bcl-2 overexpression inhibited etoposide-induced calpain activation, Bax cleavage, cytochrome c release, and apoptosis. Our results suggest that the mitochondrial calpain plays an essential role in apoptotic commitment by cleaving Bax and generating the Bax/p18 fragment, which in turn mediates cytochrome c release and initiates the apoptotic execution. 相似文献
16.
Soo Yeon Park Ha Young Kim Jung Hwan Lee Kyoung Ho Yoon Mun Seog Chang Seong Kyu Park 《Cellular & molecular biology letters》2010,15(1):1-12
To assess the dependence on age of the expression of apoptosis regulatory proteins in the human semitendinosus muscle, we
measured the expression levels of several apoptosis-related genes, including apoptosis-inducing factor (AIF), Bax, Bcl-2,
caspase-3 and heat shock protein 70 (HSP70), using RT-PCR, immunohistochemistry and TUNEL assays. We found that the DNA fragmentation
was proportional to the age of the tissues sample donors. The expression levels of AIF were significantly elevated (by 10
to 25%) in semitendinosus tissue samples from older individuals, but the Bax, Bcl-2, caspase-3 and HSP 70 levels remained
almost constant. This data suggests that the morphological and functional changes observed in aged human semitendinosus muscle
correlates with the apoptosis of muscle cells through the induction of AIF. 相似文献
17.
Neuroblastoma is a solid tumor that mostly occurs in children. Malignant neuroblastomas have poor prognosis because conventional chemotherapeutic agents are hardly effective. Survivin, which is highly expressed in some malignant neuroblastomas, plays a significant role in inhibiting differentiation and apoptosis and promoting cell proliferation, invasion, and angiogenesis. We examined consequences of survivin knockdown by survivin short hairpin RNA (shRNA) plasmid and then treatment with (-)-epigallocatechin-3-gallate (EGCG), a green tea flavonoid, in malignant neuroblastoma cells. Our Western blotting and laser scanning confocal immunofluorescence microscopy showed that survivin was highly expressed in malignant neuroblastoma SK-N-BE2 and SH-SY5Y cell lines and slightly in SK-N-DZ cell line. Expression of survivin was very faint in malignant neuroblastoma IMR32 cell line. We transfected SK-N-BE2 and SH-SY-5Y cells with survivin shRNA, treated with EGCG, and confirmed knockdown of survivin at mRNA and protein levels. Survivin knockdown induced morphological features of neuronal differentiation, as we observed following in situ methylene blue staining. Combination of survivin shRNA and EGCG promoted neuronal differentiation biochemically by increases in the expression of NFP, NSE, and e-cadherin and also decreases in the expression of Notch-1, ID2, hTERT, and PCNA. Our in situ Wright staining and Annexin V-FITC/PI staining showed that combination therapy was highly effective in inducing, respectively, morphological and biochemical features of apoptosis. Apoptosis occurred with activation of caspase-8 and cleavage of Bid to tBid, increase in Bax:Bcl-2 ratio, mitochondrial release of cytochrome c, and increases in the expression and activity of calpain and caspase-3. Combination therapy decreased migration of cells through matrigel and inhibited proliferative (p-Akt and NF-κB), invasive (MMP-2 and MMP-9), and angiogenic (VEGF and b-FGF) factors. Also, in vitro network formation ability of cells was significantly inhibited by survivin silencing and completely by combination of survivin silencing and EGCG treatment. Collectively, survivin silencing potentiated anti-cancer effects of EGCG in human malignant neuroblastoma cells having survivin overexpression. 相似文献
18.
Fatemeh Shaerzadeh Shabnam Zeighamy Alamdary Mohammad Ali Esmaeili Nazanin Namazi Sarvestani Fariba Khodagholi 《Neurochemical research》2011,36(12):2216-2226
Herein, we investigated the protective effect of Salvia sahendica against H2O2-induced cell death in rat pheochromocytoma (PC12) cells. Our data show that S. sahendica blocks apoptosis pathway by inhibition of cytochrome c release from mitochondria and leakage of calcium from endoplasmic reticulum. It also activates/inactivates two members of
Bcl-2 family, Bax and Bcl-2. Bax inhibition and Bcl-2 activation suppress release of cytochrome c from mitochondria that prevents cleavage of caspase-3. Besides S. sahendica suppresses ER stress via attenuation of intracellular levels of calcium. Suppression of ER stress decreased calpain activation
and subsequently cleavage of caspase-12. Altogether, these results indicate that S. sahendica protects PC12 cells treated with H2O2 via suppression of upstream factors of apoptosis pathway. While oxidative stress is an early event in Alzheimer disease,
it seems that S. sahendica prevents deleterious effects of reactive oxygen species by stabilizing mitochondrial membranes and inhibiting ER stress. 相似文献
19.
Zhiqun Zhang Stephen F. Larner Ming Cheng Liu Wenrong Zheng Ronald L. Hayes Kevin K. W. Wang 《Apoptosis : an international journal on programmed cell death》2009,14(11):1289-1298
Apoptosis and oncotic necrosis in neuronal and glial cells have been documented in many neurological diseases. Distinguishing
between these two major types of cell death in different neurological diseases is needed in order to better reveal the injury
mechanisms so as to open up opportunities for therapy development. Accumulating evidence suggests apoptosis and oncosis epitomize
the extreme ends of a broad spectrum of morphological and biochemical events. Biochemical markers that can distinguish between
the calpain and caspase dominated types of cell death would help in this process. In this study, three chemical agents, maitotoxin
(MTX), staurosporine (STS) and thylenediaminetetraacetic acid (EDTA), were used to induce different types of cell death in
PC12 neuronal-like cells. MTX-induced necrosis, as determined by the increased levels of calpain-specific cleaved fragments
of spectrin by antibodies specific to the calpain-cleaved 150 kDa αII-spectrin breakdown product (SBDP150) and 145 kDa αII-spectrin
breakdown product (SBDP145). In this paradigm, there were no detectable SBDP150i and SBDP120 fragments as determined by antibodies
specific to the caspase-cleaved specific fragments similar to those seen in the EDTA-mediated apoptotic PC-12 cells. In contrast
to the calpain specific MTX necrosis treatment and the caspase EDTA apoptotic treatment is the STS treatment which induced
both proteases as shown by the increase in all the SBDP fragments. Furthermore, compared to SBDP150, SBDP145 appears to be
a more specific and sensitive biomarker for calpain activation. Taken together, our results suggested calpains and caspases
which dominate the two major types of cell death could be independently discriminated by specifically examining the multiple
αII-spectrin cleavage breakdown products. 相似文献
20.
Liu JF Fong YC Chang KW Kuo SC Chang CS Tang CH 《Journal of cellular biochemistry》2011,112(2):453-462
Chondrosarcoma is a malignant primary bone tumor that responds poorly to both chemotherapy and radiation therapy. The aim of this study was to elucidate the mechanism of the novel Combretastatin A-4 derivative, 2-(furanyl)-5-(pyrrolidinyl)-1-(3,4,5-trimethoxybenzyl)benzoimidazole (FPTB)-induced human chondrosarcoma cells apoptosis. FPTB induced cell apoptosis in human chondrosarcoma cell line but not primary chondrocytes. FPTB induced up-regulation of Bax and Bak, down-regulation of Bcl-2 and Bcl-XL and dysfunction of mitochondria in chondrosarcoma. FPTB also triggered endoplasmic reticulum (ER) stress, as indicated by changes in cytosol-calcium levels. We found that FPTB increased glucose-regulated proteins (GRP)78 but not GRP94 expression. In addition, treatment of cells with FPTB induced calpain expression and activity. Transfection of cells with GRP78 or calpain siRNA reduced FPTB-mediated cell apoptosis. Therefore, FPTB-induced apoptosis in chondrosarcoma cells through the mitochondria dysfunction and involves caspase-9 and caspase-3-mediated mechanism. FPTB also induced cell death mediated by increasing ER stress, GPR78 activation, and Ca(2+) release, which subsequently triggers calpain, caspase-12 and caspase-3 activity, resulting in apoptosis. 相似文献