• Molecules and Cells
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• v.38 no.4
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• pp.373-379
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• 2015

Pyruvate kinase M2 isoform (PKM2), a rate-limiting enzyme in the final step of glycolysis, is known to be associated with the metabolic rewiring of cancer cells, and considered an important cancer therapeutic target. Herein, we report a novel PKM2 activator, PA-12, which was identified via the molecular docking-based virtual screening. We demonstrate that PA-12 stimulates the pyruvate kinase activity of recombinant PKM2 in vitro, with a half-maximal activity concentration of $4.92{\mu}M$, and effectively suppresses both anchorage-dependent and -independent growth of lung cancer cells in non-essential amino acid-depleted medium. In addition, PA-12 blocked the nuclear translocalization of PKM2 in lung cancer cells, resulting in the inhibition of hypoxia response element (HRE)-mediated reporter activity as well as hypoxia-inducible factor 1 (HIF-1) target gene expression, eventually leading to the suppression of cell viability under hypoxia. We also verified that the effects of PA-12 were dependent on PKM2 expression in cancer cells, demonstrating the specificity of PA-12 for PKM2 protein. Taken together, our data suggest that PA-12 is a novel and potent PKM2 activator that has therapeutic implications for lung cancer.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.3
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• pp.395-402
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• 2018

Objective: An experiment was conducted to evaluate effects of inclusion level of palm kernel meal (PKM) and adaptation duration on the digestible energy (DE) and apparent total tract digestibility (ATTD) of chemical constituents in diets fed to growing-finishing pigs. Methods: Thirty crossbred barrows ($Duroc{\times}Landrace{\times}Large\;White$) with an average initial body weight of $85.0{\pm}2.1kg$ were fed 5 diets in a completely randomized design. The diets included a corn-soybean meal basal diet and 4 additional diets in which corn and soybean meal were partly replaced by 10%, 20%, 30%, or 40% PKM. After 7 d of adaptation to the experimental diets, feces were collected from d 8 to 12, d 15 to 19, d 22 to 26, and d 29 to 33, respectively. Results: The DE and ATTD of gross energy (GE), dry matter (DM), ash, organic matter (OM), neutral detergent fiber (NDF), acid detergent fiber (ADF), and crude protein (CP) in diets decreased linearly as the dietary PKM increased within each adaptation duration (p<0.01). Diet containing 19.5% PKM had less DE value and ATTD of all detected items compared with other diets when fed to pigs for 14 days (p<0.05). The ATTD of CP in PKM calculated by 19.5% and 39.0% linearly increased as adaptation duration prolonged from 7 to 28 days (p<0 .01). Conclusion: Inclusion level of PKM and adaptation duration had an interactive effect on DE and the ATTD of GE, DM, OM, and CP (p<0.01 or 0.05) but ash, NDF, and ADF in diet (p>0.05). Considering a stable determination, 21 days of adaptation to a diet containing 19.5% PKM is needed in pigs and a longer adaptation time is recommended as dietary PKM increases.

• Molecules and Cells
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• v.41 no.6
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• pp.562-574
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• 2018

The tazarotene-induced gene 1 (TIG1) protein is a retinoidinducible growth regulator and is considered a tumor suppressor. Here, we show that DnaJ heat shock protein family member C8 (DNAJC8) is a TIG1 target that regulates glycolysis. Ectopic DNAJC8 expression induced the translocation of pyruvate kinase M2 (PKM2) into the nucleus, subsequently inducing glucose transporter 1 (GLUT1) expression to promote glucose uptake. Silencing either DNAJC8 or PKM2 alleviated the upregulation of GLUT1 expression and glucose uptake induced by ectopic DNAJC8 expression. TIG1 interacted with DNAJC8 in the cytosol, and this interaction completely blocked DNAJC8-mediated PKM2 translocation and inhibited glucose uptake. Furthermore, increased glycose uptake was observed in cells in which TIG1 was silenced. In conclusion, TIG1 acts as a pivotal repressor of DNAJC8 to enhance glucose uptake by partially regulating PKM2 translocation.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.5
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• pp.1961-1970
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• 2014

Pyruvate kinase isozyme type M2 (PKM2) was first found in hepatocellular carcinoma (HCC), and its expression has been thought to correlate with prognosis. A large number of studies have demonstrated that epithelial-mesenchymal transition (EMT) is a crucial event in hepatocellular carcinoma (HCC) and associated metastasis, resulting in enhanced malignancy of HCC. However, the roles of PKM2 in HCC EMT and metastasis remain largely unknown. The present study aimed to determine the effects of PKM2 in EGF-induced HCC EMT and elucidate the molecular mechanisms in vitro. Our results showed that EGF promoted EMT in HCC cell lines as evidenced by altered morphology, expression of EMT-associated markers, and enhanced invasion capacity. Furthermore, the present study also revealed that nuclear translocation of PKM2, which is regulated by the ERK pathway, regulated ${\beta}$-catenin-TCF/LEF-1 transcriptional activity and associated EMT in HCC cell lines. These discoveries provide evidence of novel roles of PKM2 in the progression of HCC and potential therapeutic target for advanced cases.

• Korean Journal of Microbiology
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• v.47 no.3
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• pp.225-230
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• 2011

A bacterium producing the extracellular mannanase and xylanase was isolated from Korean farm soil by successive subcultures in a minimal medium supplemented with palm kernel meal (PKM) and rice bran. The isolate YB-1106 showed 98% similarity with Microbacterium arabinogalactanolyticum on the basis of 16S rRNA gene sequences. The additional carbohydrates including locust bean gum (LBG) and PKM increased the mannanase productivity of the YB-1106, while the xylanase productivity of the isolate was increased by wheat bran, oat spelt xylan, rice bran and xylose. Particularly, maximum mannanase and xylanase activities were obtained in the culture filtrate of tryptic soy broth supplemented with 1% LBG or 2% wheat bran, respectively. Both enzyme activities were produced at stationary growth phase. The mannanase of culture supernatant was the most active at $50^{\circ}C$ and pH 6.0, while xylanase of culture supernatant was the most active at $55^{\circ}C$ and pH 6.5. The predominant products resulting from the mannanase or xylanase hydrolysis were oligosaccharides for LBG or xylan, respectively.

• BMB Reports
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• v.44 no.4
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• pp.279-284
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• 2011

The glutathione S-transferase (GST) system is useful for increasing protein solubility and purifying soluble GST fusion proteins. However, purifying half of the GST fusion proteins is still difficult, because they are virtually insoluble under non-denaturing conditions. To optimize a simple and rapid purification condition for GST-pyruvate kinase muscle 2 (GST-PKM2) protein, we used 1% sarkosyl for lysis and a 1 : 200 ratio of sarkosyl to Triton X-100 (S-T) for purification. We purified the GST-PKM2 protein with a high yield, approximately 5 mg/L culture, which was 33 times higher than that prepared using a conventional method. Notably, the GST-high-temperature requirement A2 (GST-HtrA2) protein, used as a model protein for functional activity, fully maintained its proteolytic activity, even when purified under our S-T condition. This method may be useful to apply to other biologically important proteins that become highly insoluble in the prokaryotic expression system.

• Korean Journal of Agricultural Science
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• v.37 no.2
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• pp.239-243
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• 2010

The objective of this study was to evaluate effects of supplementation of ${\beta}$-mannanase (CTCZYME$^{(R)}$, CTCBIO, Inc.) on feed intake, growth performance and fecal health of calves fed two levels (3% vs. 8%) of palm kernel meal (PKM). A total of nine Holstein calves were divided into three groups, and fed a conventional starter containing 3% PKM (CON), CON+0.1% CTCZYME$^{(R)}$ (TRT1), or a starter containing 8% PKM+0.1% CTCZYME$^{(R)}$ (TRT2). No clinical symptom of calves was observed through the trial. We did not find significant differences among the treatments on mean feed intake, growth performance, or fecal health during the four-week experimental period. Feed efficiency tended to be improved by adding CTCZYME$^{(R)}$ (0.46, 0.87 and 0.52 for CON, TRT1 and TRT2, respectively). Compared with CON (921 g/d and 786 g/d), TRT2 had lower feed intake (727 g/d) and average daily gain (ADG, 631 g/d) before weaning. However, feed intake (2300 g/d) and ADG (1012 g/d) were similar or even higher in TRT2 than CON (2269 g/d and 560 g/d) after weaning. This was probably due to the effect of a large amount of mannan-oligosaccharide released from PKM by ${\beta}$-mannanase. Salmonella was not detected any fecal samples. No significant difference was observed in the number of fecal E. coli or fecal properties including color, smell, and watery indexes among the treatments. We conclude that a calf starter containing 8% PKM with 0.1% CTCZYME$^{(R)}$ is comparable with a conventional starter in feed intake and growth performance of calf, which is beneficial in terms of reduction in feed cost.

• Toxicological Research
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• v.32 no.1
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• pp.47-56
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• 2016

The identification of biomarkers for the early detection of acute kidney injury (AKI) is clinically important. Acute kidney injury (AKI) in critically ill patients is closely associated with increased morbidity and mortality. Conventional biomarkers, such as serum creatinine (SCr) and blood urea nitrogen (BUN), are frequently used to diagnose AKI. However, these biomarkers increase only after significant structural damage has occurred. Recent efforts have focused on identification and validation of new noninvasive biomarkers for the early detection of AKI, prior to extensive structural damage. Furthermore, AKI biomarkers can provide valuable insight into the molecular mechanisms of this complex and heterogeneous disease. Our previous study suggested that pyruvate kinase M2 (PKM2), which is excreted in the urine, is a sensitive biomarker for nephrotoxicity. To appropriately and optimally utilize PKM2 as a biomarker for AKI requires its complete characterization. This review highlights the major studies that have addressed the diagnostic and prognostic predictive power of biomarkers for AKI and assesses the potential usage of PKM2 as an early biomarker for AKI. We summarize the current state of knowledge regarding the role of biomarkers and the molecular and cellular mechanisms of AKI. This review will elucidate the biological basis of specific biomarkers that will contribute to improving the early detection and diagnosis of AKI.

• Information and Communications Magazine
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• v.24 no.11
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• pp.5-13
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• 2007

광대역 무선 접속 표준을 관장하는 IEEE 802.16 워킹 그룹은 IEEE 802.16 표준을 2004년에 발표하였으며 이 IEEE 802.16 표준안에는 현재 WiMAX(Worldwide Interoperability for Microwave Access)라 불리는 고정 및 저속 이동 접속에 대한 광대역 무선 통신 지원 기술이 포함되어 있다. 특히 여러 기술 중 보안 관점에서 IEEE 802.16 표준은 MAC 계층 안에 PKM(Privacy Key Management)라고 불리는 Security Sub-layer를 가지고 있다. PKM은 PKMv1과 PKMv2로 구분되며, 먼저 PKMv1은 기본적인 인증 및 기밀성 기능을 제공하고 IEEE 802.16 표준에 기본적으로 적용되어있다. 하지만, IEEE 802.16 표준 이후 많은 연구들이 PKMv1의 보안성에 대하여 의문을 제기하였고 이에 따라 IEEE 802.16 표준안의 확장 개선안으로서 완전한 이동성을 바탕으로 하는 2005년 발표된 IEEE 802.16e 표준안에서는 향상된 보안 기능을 제공하는 PKMv2를 제공하며 기존 표준안의 부족한 점을 보완하기 위하여 시도하였다. 이러한 PKMv2는 EAP(Extensible Authentication Protocol) 인증, AES(Advanced Encryption Standard) 기반 기밀성 제공 알고리즘, CMAC/HMAC(Cipher/Hashed Message Authentication Code)을 사용한 메시지 인증 기능 제공 등 보다 다양한 보안 기능을 제공하였다. 그러나 IEEE 802.16e 표준안의 보안 기능은 SS(Subscriber Station)과 BS(Base Station)간의 통신구간 보안에 초점을 맞추어서 네트워크 도메인간의 보안 문제나 핸드오버시 보안과 같은 네트워크 구조적 보안 취약성을 여전히 가지고 있다. 하지만 표준안에서 정의하고 있는 SS와 BS 구간 보안 역시 완전한 솔루션을 제시하고 있지는 않다. 본 논문에서는 이러한 취약성을 고찰하고 그에 따른 대응방안을 제시하였다.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.7
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• pp.946-950
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• 2014

Bacillus licheniformis was grown in minimal nutrient medium containing 1% (w/v) of distillers dried grain with soluble (DDGS), palm kernel meal (PKM), wheat bran (WB) or copra meal (CM), and the enzyme activity of endoglucanase, ${\beta}$-glucosidase, xylanase and reducing sugars was measured to investigate a possibility of using cost-effective agricultural residues in producing cellulolytic and hemicellulolytic enzymes. The CM gave the highest endoglucanase activity of 0.68 units/mL among added substrates at 48 h. CM yielded the highest titres of 0.58 units/ml of ${\beta}$-glucosidase, compared to 0.33, 0.23, and 0.16 units/mL by PKM, WB, and DDGS, respectively, at 72 h. Xylanase production was the highest (0.34 units/mL) when CM was added. The supernatant from fermentation of CM had the highest reducing sugars than other additional substrates at all intervals (0.10, 0.12, 0.10, and 0.11 mg/mL respectively). It is concluded that Bacillus licheniformis is capable of producing multiple cellulo- and hemicellololytic enzymes for bioethanol production using cost-effective agricultural residues, especially CM, as a sole nutrient source.