• Korean Journal of Veterinary Research
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• v.36 no.4
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• pp.783-794
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• 1996

It has been suggested that ion transport systems are intimately involved in mediating the effects of growth regulatory factors on the growth of a number of different types of animal cells in vivo. The functional importance of the apical membrane $Na^+/H^+$ antiporter in the renal proximal tubule is evidenced by estimates that this transporter mediates the reabsorption of approximately one third of the filtered load of sodium and the bulk of the secretion of hydrogen ions. This study was designed to investigate the pathway utilized by IGF-I in regulating sodium transport in primary cultured renal proximal tubule cells. Results were as follows : 1. $Na^+$ was observed to accumulate in the primary cells as a function of time. Raising the concentration of extracellular NaCl induced an decrease in $Na^+$ uptake compared with control cells in a dose dependent manner. The rate of $Na^+$ uptake into the primary cells was about two times higher in the absence of NaCl($40.11{\pm}1.76pmole\;Na^+/mg\;protein/min$) than in the presence of 140mM NaCl($17.82{\pm}0.94pmole\;Na^+/mg\;protein/min$) at the 30 minute uptake. 2. $Na^+$ uptake was inhibited by IAA($1{\times}10^{-4}M$) or valinomycin($5{\times}10^{-6}M$) treatment($50.51{\pm}4.04$ and $57.65{\pm}2.27$ of that of control, respectively). $Na^+$ uptake by the primary proximal tubule cells was significantly increased by ouabain($5{\times}10^{-5}M$) treatment($140.23{\pm}3.37%$ of that of control). When actinomycin D($1{\times}10^{-7}M$) or cycloheximide($4{\times}10^{-5}M$) was applied, $Na^+$ uptake was decreased to $90.21{\pm}2.39%$ or $89.64{\pm}3.69%$ of control in IGF-I($1{\times}10^{-5}M$) treated cells, respectively. 3. Extracellular cAMP decreased $Na^+$ uptake in a dose-dependent manner($10^{-8}-10^{-4}M$). IBMX($5{\times}10^{-5}M$) also inhibited $Na^+$ uptake. Treatment of cells with pertussis toxin(50pg/ml) or cholera toxin($1{\mu}g/ml$) inhibited $Na^+$ uptake. Extracellular PMA decreased $Na^+$ uptake in a dose-dependent manner(1-100ng/ml). 100 ng/ml PMA concentration significantly inhibited $Na^+$ uptake in IGF-I treated cells. However, staurosporine($1{\times}10^{-7}M$) had no effect on $Na^+$ uptake. When PMA and staurosporine were added together, the inhibition of $Na^+$ uptake was not observed. In conclusion, sodium uptake in primary cultured rabbit renal proximal tubule cells was dependent on membrane potentials and intracellular energy levels. IGF-I stimulates sodium uptake through mechanisms that involve some degree of de novo protein and/or RNA synthesis, and cAMP and/or PKC pathway mediating the action mechanisms of IGF-I.

• Clinical and Experimental Pediatrics
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• v.46 no.2
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• pp.143-153
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• 2003

Purpose : Infection with Shiga-like toxin (SLT)-producing Escherichia coli, an emerging human pathogen found particularly in young children under 5 years of age, causes a spectrum of illnesses with high morbidity and mortality, ranging from diarrhea to hemorrhagic colitis and hemolytic uremic syndrome. Host mediators play an important role in the pathogenesis of SLT-I toxicity. The experiments described here were designed to investigate the effect of SLT-I on TNF-${\alpha}$ production and to understand the effect of TNF-${\alpha}$ on GB3 expression. We also further examine the relationship between the Gb3 level and the differential susceptibility of cells to the cytotoxic action of SLT-I. Methods : The effect of purified SLT-1 from E. coli O157 : H7 (ATCC 43890) on tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) production in Raw264.7 cells was investigated. Many mediators regulate endothelial cell membrane expression of the glycolipid globotriaosyleramide (Gb3), which serves as the toxin receptor, suggesting that the host response to the toxin or other bacterial products may contribute to pathogenesis by regulating target cell sensitivity to the toxins. Therefore, the relationships between Gb3 expression and cytotoxicity against SLT-I on three types of cells were evaluated. Results : Detectable levels of TNF-${\alpha}$ were produced as early as six hours after induction and continued to increase during 48 hours by SLT-I. It was also found that Vero cells and dendritic cells (DC2.4 cells) expressed high levels of Gb3, 83% and 68%, respectively, and that Raw264.7 cells had a low level of Gb3 (29%) and appeared refractory to cytotoxicity against SLT-I. Vero cells and DC2.4 cells expressing high levels of Gb3 were highly susceptible to SLT-I. Furthermore, macrophages showed a resistance to SLT-I cytotoxicity, despite the fact that Gb3 expression was enhanced. Conclusion : These results strongly suggest that the expression of Gb3 is necessary but not sufficient to confer sensitivity of macrophages to SLT-I and further underpin the important role of SLT-I and its Gb3 receptors in the pathogenesis of E. coli O157 infection.

• Environmental Analysis Health and Toxicology
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• v.18 no.2
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• pp.89-94
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• 2003

Tributyltin (TBT) used world-wide in antifouling paints for ships is a widespread environmental pollutant and cause reproductive organs atrophy in rodents. At low doses, antiproliferative modes of action have been shown to be involved, whereas at higher doses apoptosis seems to be the mechanism of toxicity in reproductive organs by TBT. In this study, we investigated that the mechanisms underlying DNA fragmentation induced by TBT in the rat leyding cell line, R2C. Effects of TBT on intracellular Ca$\^$2+/ level and reactive oxygen species (ROS) were investigated in R2C cells by fluorescence detector. TBT significantly induced intracellular Ca$\^$2+/ level in a time-dependent manner. The rise in intracellular Ca$\^$2+/ level was followed by a time-dependent generation of reactive oxygen species (ROS) at the cytosol level. Simultaneously, TBT induced the release of cytochrome c from the mitochondrial membrane into the cytosol. Furthermore, ROS production and the release of cytochrome c were reduced by BAPTA, an intracellular Ca$\^$2+/ chelator, indicating the important role of Ca$\^$2+/ in R2C during these early intracellular events. In addition, Z-DEVD FMK, a caspase-3 inhibitor, decreased apoptosis by TBT. Taken together, the present results indicated that the apoptotic pathway by TBT might start with an increase in intracellular Ca$\^$2+/ level, continues with release of ROS and cytochrome c from mitochondria, activation of caspases,and finally results in DNA fragmentation.

• Journal of Life Science
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• v.16 no.2 s.75
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• pp.315-322
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• 2006

FS11052, a novel microbial metabolite from Streptomyces spp. was identified as a small molecular substance and shown inhibition activities for the release of neurotransmitter from rat hippocampal neuron and PC12 cells. FS11052 is an inhibitor of tritiated norepinephrine ($[^3H]-NE$) release in high $K^+$ buffer solution containing ionomycin, indicating that FS11052 inhibits neurotransmitter release after the influx of $Ca^{2+}$ ions. When examined the effect of FS11052 on glucuronidase release from guinea pig neutrophils, FS11052 inhibited glucuronidase release: when treated with $5{\mu}g/ml$ of FS11052, which was not induced cellular cytotoxicity. The fact that the glucuronidase release in neutrophil and norepinephrine release in neuron was inhibited suggests the similarity in the locations and the mechanisms of FS11052 action targets. When treated with $5{\mu}g/ml$ of FS11052, $[^3H]-NE$ release and neurite extension for both rat hippocampal neurons and PC12 cells were prevented. These observations of FS11052 functioning as an inhibitor of neurotransmitter release suggest that FS11052 has an important role in synaptic transmission in neuron.

• Journal of Plant Biotechnology
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• v.33 no.1
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• pp.1-9
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• 2006

Peroxiredoxins (Prxs) are ubiquitously distributed and play important functions in diverse cellular signaling systems. The proteins are largely classified into three groups, such as typical 2-Cys Prx, atypical 2-Cys Prx, and 1-Cys Prx, that are distinguished by their catalytic mechanisms and number of Cys residues. From the three classes of Prxs, the typical 2-Cys Prx containing the two-conserved Cys residues at its N-terminus and C-terminus catalyzes $H_2O_2$ with the use of thioredoxin (Trx) as an electron donor. During the catalytic cycle, the N-terminal Cys residue undergoes a peroxide-dependent oxidation to sulfenic acid, which can be further oxidized to sulfinic acid at the presence of high concentrations of $H_2O_2$ and a Trx system containing Trx, Trx reductase, and NADPH. The sulfinic acid form of 2-Cys Prx is reduced by the action of sulfiredoxin which requires ATP as an energy source. Under the strong oxidative or heat shock stress conditions, 2-Cys Prx in eukaryotes rapidly switches its protein structure from low-molecular-weight species to high-molecular-weight protein structures. In accordance with its structural changes, the protein concomitantly triggers functional switching from a peroxidase to a molecular chaperone, which can protect its substrate denaturation from external stress. In addition to its N-terminal active site, the C-terminal domain including 'YF-motif' of 2-Cys Prx plays a critical role in the structural changes. Therefore, the C-terminal truncated 2-Cys Prxs are not able to regulate their protein structures and highly resistant to $H_2O_2$-dependent hyperoxidation, suggesting that the reaction is guided by the peroxidatic Cys residue. Based on the results, it may be concluded that the peroxidatic Cys of 2-Cys Prx acts as an '$H_2O_2$-sensor' in the cells. The oxidative stress-dependent regulation of 2-Cys Prx provides a means of defense systems in cells to adapt stress conditions by activating intracellular defense signaling pathways. Particularly, 2-Cys Prxs in plants are localized in chloroplasts with a dynamic protein structure. The protein undergoes conformational changes again oxidative stress. Depending on a redox-potential of the chloroplasts, the plant 2-Cys Prx forms super-molecular weight protein structures, which attach to the thylakoid membranes in a reversible manner.

• Journal of Chest Surgery
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• v.30 no.9
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• pp.854-861
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• 1997

CYPRA 21-1 is known to be a cytokeratin 19 fragment, and it can be detected by using two specific monoclonal antibodies (KS 19-1 and BM 19-21) and can be clinically applied as a useful circulating tumor marker The epidermal growth factor receptor (EGF-R) expression was evaluated and characterized by its tyrosine protein kinase activity and by its ligand-stimulated autophosphorylation, a property shared with other peptide growth factor receptors. Autocrine or para'urine action was initiated by a growth factor, or by a transforming growth factor o, which had an extensive homology with EGP and which also stimulated tyrosine kinase activity on the EGF-R. The CYFRA 21-1 and the EGF-R levels in 30 patients with primary lung tumors were investigated. There were 24 patients with squamous cell carcinomas and 6 patients with adenocarcinomas. Specimen 5 mm3 in size were sampled at three different locations ; the main lesion, the boundary between the lesion and the unaffected tissue, and the unaffected tissue of the patients. The results were as follows 1. The CYPRA 21-1 concentration in the cancer boundary, the most malignant region,(348.6 : 89.9 ng/ml) was the lowest value. The CYFRA 21-1 concentration in unaffected tissue,(718.4$\pm$77.8 ng/ml) was higher than that in the main lesion. which had intact cellularity. 2. The EGF-R concentration in the main lesion was higher than that in the unaffected tissue, and the EGF-R concentration in a squamous cell cacinoma was higher than that in an adenocarcinoma. also, the EGF-R concentration in the cancer b undary was highest at stage 1, ll. The EGF-R concentration was higher in the main cancer lesion that in the unaffected tissue at stage 111, IV. 3. The CYFRA 21-1 was a cytoplasmic skeleton and the EGF-R was a cell-wall component; there was no correlation. In conclusion, CYFRA 21-1 was abundant in the cytoplasm but had a higher concentration in the unaffected tissue than in the main cancer lesion. The CYFRA 21-1 concentration of the tissue did not reflect the amount of cancer activity, the EGP-R was located in the cell membrane, the level of tissue that reflects cancer activity, so the main cancer lesion had a higher concentration than the unaffected tissue. CYFRA 21-1 is not a useful tumor maker at the tissue level. Because the EGF-R concentration re(looted the cancer activity, its a useful tumor marker for lung cancer.

• Journal of Korean Medical classics
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• v.12 no.2
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• pp.56-71
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• 1999

1. In the recohnition of cosmos true form, It is compared to the Boundless(無極) the Great Absolute(太極),Yin and Yang(兩儀) throungh the fertilazation process of spermatozoon and ovum. 2. It is explained that principle of unchange through the Form and Action(體 用) relation of the outer appearances and Number (象數) with matching the number of nine and ten to HaDoo(河圖) and RakSye(洛書). 3. Eigth divinations(八卦) being compared to the human body, Care presevation of pregnancy(養胎) is explained that head forms firstly(Gun-I 1乾一), secondly lung(Tae-E 兌二), heart(E-Sam 離三), liver(Jin-Sa 震四), gall bladder(Son-Oo 巽五), kidney(Gam-Yuk 坎六), intestines and stomach(Gan-Chill 艮七), lastly flesh forms(Gon-Pal 坤八). 4. It is explained that process of physiological change of $\ll$Nei Ching The Natural Truth in Ancient Times$\gg$(內經 上古天眞論) by matching boy at the age of 8 to Gan-divination(艮卦), and girl at the age of 7 to Tae-divination(兌卦). 5. The theory of six sons from Gun-Gon(乾坤六子論) is explained by relation of Apriority Eight-divination(先天八卦) obedience and disobedience-left and right. 6. It is explained that form of the human-body and the relationship of the Heart - the Kidney through the Gam(坎) Li(離) - divination 7. The effort of interpretating time and space of the Twelve Horary signs is explanined by season, direction, Five elements(五行), rise and decline, the Three Sum(三合), the Six Sum (六合), the six crash(六衡)'s relation. 8. the process of change from apriority(先天) to postery(後天) in the book of Changes(周易) is explanined by comparing to the phenomenum of nature and the human body. 9. The Energy Satus(氣位) are different from the direction of Eight-divination(八卦) and the properties of the good or bad of herb-drugs are differnt from the place of production. 10. The rightness of realizating the Overlapping-divinations(重卦) are compared to the phenomenum of nature through the Divination Virture(卦德). 11. The dependence-relations of The Twelve Meridians(十二經脈) are explained by-matching January with liver meridian, February with gall bladder meridian, march with heart pericardium meridiam, April with small intestine meridkan, August with lung spleen meridian, jury with stomach meridian, August with lung meridian, September with large intestine meridian, October with urinary bladder meridianm November with kidney meridian. December with triple energizer meridian throng The Twelve Byuk-divination. 12. The process of menstration cycle is explained by The Month symbolizing-divination(月候卦). 13. Through The Trade(交易) prove the reason of feverish sympotoms to use feverish Drug, mill sympotoms to use mill drug of prescription and Heart-Kidneys Consensus(心賢相交) and through The Change(變易), prove the chill and feverish consensus of forechill after feverish, fore feverish after chill and through. The Non-Change(不易) explain the reason of chill sympotoms to use feverish drug, feverish sympotoms to use chill drug of prscription. 14. Ho-divination(互卦) applicate Jxa Sa(佐使) herb drug match of Kun Sin Jwa Sa() theory. 15. According to the Hyo-position(爻位) match the ages, body form and drug by matching Ehight-divination(八卦) to the human body form and function in medicine and the book of Changes(周易) application emphasize the human body Ehight-divination(人身八卦). 16. Throgh the Order-divination(序卦) explain the rightness of Divination Image(卦象) arrangement and all things take shape by cosmo-energy conseusus(宇宙氣交). 17. Throgh the Mixing-divination(難卦) supply the vacancy of medicine and the book of Changes(周易) relationship in the foreword explian the human energy movements, sleep, vomitting, the energy arrival(逮氣), heart pericardium(心包), lung membrane(肺膜) etc.... Like the above sentence medicine and the book of Changes(周易) theory of scholar Tang on the viewpoint of easten-the way Western appliance(東道西器) researching abyss of medicine impart to descendants, so I think that the achievement of medicine and the book of Changes(周易) study is very excellant and I expect that the study Korean Oriental Medicine(韓醫學) theory by means of medicine the book of Changes(周易) reference, will be accelarated.

• The Korean Journal of Pharmacology
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• v.30 no.3
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• pp.273-289
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• 1994

Reversible brain ischemia was produced by occluding both common carotid arteries for 5 min, and the effects of aminoguanidine (AG), $DL-{\alpha}-difluoromethylornithine$ (DFMO), MK-801, and nimodipine (NM) on the ischemia induced changes of the polyamine, glutamate and acetylcholine levels in the hippocampus CA1 subfield and the specific $[^3H]\;MK-801$ binding to the hippocampus synaptosomal membranes were studied with a histological reference of the cresyl violet stained hippocampus. The basal putrescine level $(PT:\;74.4{\pm}8.8\;nM)$ showed a rapid increase (up to 1.7 fold) for 5 min of ischemia, remained significantly increased for 6 h, and then resumed the further increase to amount gradually up to about 3 fold 96 h after recirculation. However, the level of spermidine was little changed, and the spermine level showed a transient increase during ischemia followed by a sustained decrease to about 40% of the preischemic level after recirculation. The increase of PT level induced by brain ischemia was enhanced with AG or MK-801, but it was reduced by DFMO or NM. The basal glutamate level $(GT:\;0.90{\pm}0.l4\;{\mu}M)$ rapidly increased to a peak level of $8.19{\pm}1.14\;{\mu}M$ within 5 min after onset of the ischemia and then decreased to the preischemic level in about 25 min after recirculation. And NM reduced the ischemia induced increase of GT level by about 25%, but AG, DFMO and MK-801 did not affect the GT increase. The basal acetylcholine level $(ACh:\;118.0{\pm}10.5\;{\mu}M)$ did little change during/after brain ischemia and was little affected by AG or NM. But DFMO and MK-801, respectively, produced the moderate decrease of ACh level. The specific $[^3H]\;MK-801$ binding to the hippocampus synaptosomal membrane was little affected by brain ischemia for 5 min. The control value (78.9 fmole/mg protein) was moderately decreased by AG and MK-801, respectively but was little changed by DFMO or NM. The microscopic findings of the brains extirpated on day 7 after ischemia showed severe neuronal damage of the hippocampus, particularly CA1 subfield. NM and AG moderately attenuated the delayed neuronal damage, and DFMO, on the contrary, aggravated the ischemia induced damage. However, MK-801 did not protect the hippocampus from ischemic damage. These results suggest that unlike to the mode of anti-ischemic action of NM, AG might protect the hippocampus from ischemic injury as being negatively regulatory on the N-methyl-D-aspartate (NMDA) receptor function in the hippocampus.

• Journal of Periodontal and Implant Science
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• v.26 no.4
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• pp.949-965
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• 1996

The main goal of periodontal therapy is to restore the lost periodontal tissue and establish the attachment appratus. Current acceptable therapeutic techniques are included : removal of diseased soft tissue, demineralization of exposed root surface, using the barrier membrane for preventing the downgrowth of gingival epithelial cell, insertion of graft materials as a scaffolding action, and biological mediators for promoting the cell activity. The latest concept one among them has been studied which based on the knowledge of cellular biology of destructed tissue. Platelet-derived growth factor(PDGF) is one of the polypeptide growth factor which have been reported as a biological mediator to regulate activities of wound healing progress including cell proliferation, migration, and metabolism. The purposes of this study is to evaluate the influences of the PDGF as biological mediator to periodontal ligament and bone marrow cell. Both right and left maxillary first molar were extracted from rat which had treated with 0.4% ${\beta}-Aminopropionitril$ for 5 days, and feeded until designed date to sacrifice under anesthesisa. Periodontal ligament were removed from the extracted socket of the rat, and cultured with Dulbecco's Modified Essential Medium(DMEM) contained with 10% Fetal Bovine Serum, 100U/ml penicillin, $100{\mu}g/ml$ streptomycin, $0.5{\mu}g/ml$ amphotericin-B. Bone marrow cell were culture from bone marrow suspension with which washed out from femur with same medium. The study was performed to evaluate the effect of PDGF to periodontal ligament and bone cell, cell proliferation rate, total protein synthesis, and alkaline phosphatase activity of rat periodontal ligament(PDL) cell and bone stromal(RBS) cell in vitro. The effects of growth factors on both cells were measured at 3, 5th day after cell culture with (control group) or without growth factors(experimental group). The results were as follows: 1. The tendency of cell proliferation under the influence of PDGF showed more rapid proliferation pattern than control at 3 and 5 days after inoculation. 2. The activity of Alkaline phosphatase revealed 14, 80% increased respectively at 3, 5 days culture than control group. Measurements of ALPase levels indicated that PDL cells had significantly higher activity when compared with that of co-culture groups and GF only(P<0.05). And, ALPase activity in 10 days was higher than that of 7 days(P<0.05). 3. The tendency of formation of the mineralized nodule were observed dose-depend pattern of PDL cells. There was statistically significant difference among group l(PDL 100%), 2(PDL 70%:GF 30%), and 3(PDL 50%:GF 50%)(P<0.01). But, there was no difference among group 3, 4(PDL 30%:GF 70%), and 5(GF 100%). 4. Also, the number of nodule was greater in co-culture of PDL 70% and GF 30% than in culture of PDL 70%(P<0.05). From the above results, it is assumed that the PDGF on PDL cells and RMB cell culture. GF stimulates the cell growth, which is not that of PDL cells but GF. And, the activity of ALPase depends on the ratio of PDL cells, and ALPase may relate to the initial phase of nodule formation. Also, it is thought that the calcified nodule formation principally depends on PDL cells, is inhibited by GF, and affected by cell density. In conclusion, platelet-derived growth factor can promote rapid osteogenesis during early stage of periodontal tissue regeneration.

• Journal of Life Science
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• v.21 no.7
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• pp.953-960
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• 2011

Necrosis is characterized by the cell membrane rupture and release of the cellular contents, including high-mobility group box 1 protein (HMGB1), into the extracellular microenvironment. HMGB1 acts as a transcriptional regulator in nuclei, but exerts a pro-inflammatory and tumor-promoting cytokine activity when released into the extracellular space. Its overexpression is associated with tumor progression and chemoresistance. Thus, HMGB1 acts as a clinically important molecule in tumor biology. In this study, we examined whether HMGB1 affects cell death induced by anti-cancer drugs. Here we show that HMGB1 prevented cisplatin (alkylating agent)-induced apoptosis and switched the cell fate to necrosis in MCF-7, MDA-MB231, and MDA-MB361 cells. Similar apoptosis-to-necrosis switch effects of HMGB1 were observed in cells treated with 4-HC, another alkylating agent. In contrast, HMGB1 did not exert any significant effects on docetaxel (DOC)-induced apoptosis in MCF-7 cells. We also show that cisplatin-induced apoptosis was switched to necrosis in MCF-7 multicellular tumor spheroids (MTS) that were cultured for 8 days and had necrotic cores, but DOC-induced apoptosis was prevented without the apoptosis-to-necrosis switch. Finally, the levels of RAGE, a receptor of HMGB1, were increased with extended culture of MTS. These findings demonstrate that HMGB1 switches alkylating agent-induced apoptosis to necrosis, suggesting that the strategy to prevent necrosis occurring as an undesirable action of alkylating agent-based chemotherapy should be delineated to improve the efficacy of chemotherapy for cancer.