LC-MS/MS Method for Simultaneous Analysis of Growth Hormone-Releasing Peptides and Secretagogues in Human Urine

Hophil Min,Boyoung Han,Changmin Sung,Ju-Hyung Park,Kang Mi Lee,Ho Jun Kim,김기훈,Junghyun Son,Oh-SeungKwon,Jaeick Lee 사단법인 한국질량분석학회 2016 Mass spectrometry letters Vol.7 No.3

Growth hormone (GH)-releasing peptides (GHRPs) and GH secretagogues (GHSs) are listed in the World Anti-Doping Agency (WADA) Prohibited List. In the present study, we developed and validated a method for the simultaneous analysis of seven GHRPs (alexamorelin, GHRP-1, -2, -4, -5, -6, and hexarelin) and three GHSs (anamorelin, ibutamoren, and ipamorelin) in human urine. Method validation was performed at minimum required performance levels specified by WADA technical documents (2 ng/mL) for all substances, and the method was validated with regard to selectivity (no interference), linearity (R2 > 0.9986), matrix effects (50.0%-141.2%), recovery (10.4%-100.8%), and intra- (2.8%-16.5%) and inter-day (7.0%-22.6%) precisions. The limits of detection for screening and confirmation were 0.05-0.5 ng/mL and 0.05-1 ng/mL, respectively.

LC-MS/MS Method for Simultaneous Analysis of Growth Hormone-Releasing Peptides and Secretagogues in Human Urine

Min, Hophil,Han, Boyoung,Sung, Changmin,Park, Ju-Hyung,Lee, Kang Mi,Kim, Ho Jun,Kim, Ki Hun,Son, Junghyun,Kwon, Oh-Seung,Lee, Jaeick Korean Society for Mass Spectrometry 2016 Mass spectrometry letters Vol.2 No.2

Growth hormone (GH)-releasing peptides (GHRPs) and GH secretagogues (GHSs) are listed in the World Anti-Doping Agency (WADA) Prohibited List. In the present study, we developed and validated a method for the simultaneous analysis of seven GHRPs (alexamorelin, GHRP-1, -2, -4, -5, -6, and hexarelin) and three GHSs (anamorelin, ibutamoren, and ipamorelin) in human urine. Method validation was performed at minimum required performance levels specified by WADA technical documents (2 ng/mL) for all substances, and the method was validated with regard to selectivity (no interference), linearity (R2 > 0.9986), matrix effects (50.0%-141.2%), recovery (10.4%-100.8%), and intra- (2.8%-16.5%) and inter-day (7.0%-22.6%) precisions. The limits of detection for screening and confirmation were 0.05-0.5 ng/mL and 0.05-1 ng/mL, respectively.

Label-Free Quantitative Proteomics and N-terminal Analysis of Human Metastatic Lung Cancer Cells

Min, Hophil,Han, Dohyun,Kim, Yikwon,Cho, Jee Yeon,Jin, Jonghwa,Kim, Youngsoo Korean Society for Molecular and Cellular Biology 2014 Molecules and cells Vol.37 No.6

Proteomic analysis is helpful in identifying cancerassociated proteins that are differentially expressed and fragmented that can be annotated as dysregulated networks and pathways during metastasis. To examine metastatic process in lung cancer, we performed a proteomics study by label-free quantitative analysis and N-terminal analysis in 2 human non-small-cell lung cancer cell lines with disparate metastatic potentials - NCI-H1703 (primary cell, stage I) and NCI-H1755 (metastatic cell, stage IV). We identified 2130 proteins, 1355 of which were common to both cell lines. In the label-free quantitative analysis, we used the NSAF normalization method, resulting in 242 differential expressed proteins. For the N-terminal proteome analysis, 325 N-terminal peptides, including 45 novel fragments, were identified in the 2 cell lines. Based on two proteomic analysis, 11 quantitatively expressed proteins and 8 N-terminal peptides were enriched for the focal adhesion pathway. Most proteins from the quantitative analysis were upregulated in metastatic cancer cells, whereas novel fragment of CRKL was detected only in primary cancer cells. This study increases our understanding of the NSCLC metastasis proteome.

Development of Diagnostic Biomarkers for Detecting Diabetic Retinopathy at Early Stages Using Quantitative Proteomics

Jin, Jonghwa,Min, Hophil,Kim, Sang Jin,Oh, Sohee,Kim, Kyunggon,Yu, Hyeong Gon,Park, Taesung,Kim, Youngsoo Hindawi Publishing Corporation 2016 Journal of diabetes research Vol.2016 No.-

<P>Diabetic retinopathy (DR) is a common microvascular complication caused by diabetes mellitus (DM) and is a leading cause of vision impairment and loss among adults. Here, we performed a comprehensive proteomic analysis to discover biomarkers for DR. First, to identify biomarker candidates that are specifically expressed in human vitreous, we performed data-mining on both previously published DR-related studies and our experimental data; 96 proteins were then selected. To confirm and validate the selected biomarker candidates, candidates were selected, confirmed, and validated using plasma from diabetic patients without DR (No DR) and diabetics with mild or moderate nonproliferative diabetic retinopathy (Mi or Mo NPDR) using semiquantitative multiple reaction monitoring (SQ-MRM) and stable-isotope dilution multiple reaction monitoring (SID-MRM). Additionally, we performed a multiplex assay using 15 biomarker candidates identified in the SID-MRM analysis, which resulted in merged AUC values of 0.99 (No DR versus Mo NPDR) and 0.93 (No DR versus Mi and Mo NPDR). Although further validation with a larger sample size is needed, the 4-protein marker panel (APO4, C7, CLU, and ITIH2) could represent a useful multibiomarker model for detecting the early stages of DR.</P>

Analysis of Glycerol with Isolation of Endogenous Interferences using "Dilute and Shoot" Strategy and High-Resolution Mass Spectrometry in Human Urine for Antidoping Testing

Kim, Yongseok,Min, Hophil,Sung, Changmin,Park, Ju-hyung,Son, Junghyun,Lee, Kang Mi,Kim, Ho Jun,Lee, Jaeick,Kwon, Oh-Seung,Kim, Ki Hun Korean Society for Mass Spectrometry 2016 Mass spectrometry letters Vol.7 No.4

Glycerol was identified and isolated from endogenous interferences during analysis of human urine using high-resolution mass spectrometry (HRMS) for doping control. Urinary sample preparation was simple; the samples were diluted with an organic solvent and then analyzed using a liquid chromatography-mass spectrometry ("dilute and shoot" method). Although the interfering ion peaks were observed at the similar retention time of glycerol, the inference could be identified by isolation with HRMS and further investigation. Thus, creatinine was identified as the endogenous interference for glycerol analysis and it also caused ion suppression resulting in the decrease of glycerol signal. This study reports the first identification and efficient isolation of endogenous interferences in human urine for "dilute and shoot" method. The information about ion suppression could be novel to prevent overestimation or a false result for antidoping analysis.

질량분석기를 활용한 효과적 이황화결합 분석법 개발

진종화 ( Jonghwa Jin ),민호필 ( Hophil Min ),권오승 ( Oh-seung Kwon ),오현정 ( Hyun Jeong Oh ),김종원 ( Jongwon Kim ),박철환 ( Chulhwan Park ) 한국화학공학회 2017 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.55 No.1

The determination of disulfide bonds is important for comprehensive understanding of the chemical structure of protein. So far, many strategies for the disulfide bond analysis have been suggested in terms of speed and sensitivity. However, most of these strategies have not considered free thiol residues in the target protein in the process of determining the disulfide bond. We suggested the strategy which was composed of four steps for the identification of disulfide bonds; the first step was the prediction of possible disulfide bonds, the second step was the determination of free cysteine residues, the third step was the analysis of disulfide bond using a high-resolution mass spectrometry, and the final step was the determination of disulfide bonds based on the comprehensive verification. In this study, we performed the characterization of disulfide bonds for the recombinant protein (HRPE1), where 1 and 5 inter- and intra-chain disulfide bonds were identified, respectively.

Method for Screening and Confirming Meldonium in Human Urine by High-Resolution Mass Spectrometry and Identification of Endogenous Interferences for Anti-Doping Testing

Yongseok Kim,Dawon Jeong,Hophil Min,Changmin Sung,Ju-hyung Park,Junghyun Son,Kang Mi Lee,Ho Jun Kim,Jaeick Lee,Oh-seung Kwon,Ki Hun Kim 한국질량분석학회 2017 Mass spectrometry letters Vol.8 No.2

Meldonium is a drug for treating ischemia by expanding the arteries but it can also enhance the performance of sports players. The World Anti-Doping Agency (WADA) has included it in the list of prohibited substances since 2016. Meldonium is one of the challenging substances for anti-doping testing because it is difficult to recover by general liquid-liquid or solid phase extraction due to its permanent charge and high polarity. Therefore, high-performance liquid chromatography (HPLC) is cur-rently used by injecting a diluted urine sample (known as the “dilute-and-shoot” strategy). There is no loss of target compounds in the extraction/cleanup procedure but its high matrix effect could interfere in their separation or detection from the endogenous urinary compounds. We report a single method using high-resolution mass spectrometry that can be used for both screening and confirmation, which follows the “dilute-and-shoot” strategy. In this method, the endogenous compounds` interfering peaks in the mass spectrum are separated at a high resolution of FWHM 140,000, and the results are suitable for substance detection follow-ing the WADA guidelines. The interferences in the obtained mass spectrum of the urine matrix are identified as acetylcholine, lysine, and glutamine by further analysis and database searching. Validation of the method is performed in routine anti-doping testing, and the limit of detection is 50 ng/mL. This method uses simple sample preparation and a general reverse phase HPLC column, and it can be easily applied to other substances.

Method for Screening and Confirming Meldonium in Human Urine by High-Resolution Mass Spectrometry and Identification of Endogenous Interferences for Anti-Doping Testing

Kim, Yongseok,Jeong, Dawon,Min, Hophil,Sung, Changmin,Park, Ju-hyung,Son, Junghyun,Lee, Kang Mi,Kim, Ho Jun,Lee, Jaeick,Kwon, Oh-Seung,Kim, Ki Hun Korean Society for Mass Spectrometry 2017 Mass spectrometry letters Vol.2 No.4

Meldonium is a drug for treating ischemia by expanding the arteries but it can also enhance the performance of sports players. The World Anti-Doping Agency (WADA) has included it in the list of prohibited substances since 2016. Meldonium is one of the challenging substances for anti-doping testing because it is difficult to recover by general liquid-liquid or solid phase extraction due to its permanent charge and high polarity. Therefore, high-performance liquid chromatography (HPLC) is currently used by injecting a diluted urine sample (known as the "dilute-and-shoot" strategy). There is no loss of target compounds in the extraction/cleanup procedure but its high matrix effect could interfere in their separation or detection from the endogenous urinary compounds. We report a single method using high-resolution mass spectrometry that can be used for both screening and confirmation, which follows the "dilute-and-shoot" strategy. In this method, the endogenous compounds' interfering peaks in the mass spectrum are separated at a high resolution of FWHM 140,000, and the results are suitable for substance detection following the WADA guidelines. The interferences in the obtained mass spectrum of the urine matrix are identified as acetylcholine, lysine, and glutamine by further analysis and database searching. Validation of the method is performed in routine anti-doping testing, and the limit of detection is 50 ng/mL. This method uses simple sample preparation and a general reverse phase HPLC column, and it can be easily applied to other substances.

Comparative Proteomic Profiling of Pancreatic Ductal Adenocarcinoma Cell Lines

Yikwon Kim,한도현,Hophil Min,Jonghwa Jin,이유진,김영수 한국분자세포생물학회 2014 Molecules and cells Vol.37 No.12

Pancreatic cancer is one of the most fatal cancers and is associated with limited diagnostic and therapeutic modalities. Currently, gemcitabine is the only effective drug and represents the preferred first-line treatment for chemotherapy. However, a high level of intrinsic or acquired resistance of pancreatic cancer to gemcitabine can contribute to the failure of gemcitabine treatment. To investigate the underlying molecular mechanisms for gemcitabine resistance in pancreatic cancer, we performed label-free quantification of protein expression in intrinsic gemcitabine-resistant and -sensitive human pancreatic adenocarcinoma cell lines using our improved proteomic strategy, combined with filter-aided sample preparation, single-shot liquid chromatography-mass spectrometry, enhanced spectral counting, and a statistical method based on a power law global error model. We identified 1931 proteins and quantified 787 differentially expressed proteins in the BxPC3, PANC-1, and HPDE cell lines. Bioinformatics analysis identified 15 epithelial to mesenchymal transition (EMT) markers and 13 EMT-related proteins that were closely associated with drug resistance were differentially expressed. Interestingly, 8 of these proteins were involved in glutathione and cysteine/methionine metabolism. These results suggest that proteins related to the EMT and glutathione metabolism play important roles in the development of intrinsic gemcitabine resistance by pancreatic cancer cell lines.

Comparative Proteomic Profiling of Pancreatic Ductal Adenocarcinoma Cell Lines

Kim, Yikwon,Han, Dohyun,Min, Hophil,Jin, Jonghwa,Yi, Eugene C.,Kim, Youngsoo Korean Society for Molecular and Cellular Biology 2014 Molecules and cells Vol.37 No.12

Pancreatic cancer is one of the most fatal cancers and is associated with limited diagnostic and therapeutic modalities. Currently, gemcitabine is the only effective drug and represents the preferred first-line treatment for chemotherapy. However, a high level of intrinsic or acquired resistance of pancreatic cancer to gemcitabine can contribute to the failure of gemcitabine treatment. To investigate the underlying molecular mechanisms for gemcitabine resistance in pancreatic cancer, we performed label-free quantification of protein expression in intrinsic gemcitabine-resistant and -sensitive human pancreatic adenocarcinoma cell lines using our improved proteomic strategy, combined with filter-aided sample preparation, single-shot liquid chromatography-mass spectrometry, enhanced spectral counting, and a statistical method based on a power law global error model. We identified 1931 proteins and quantified 787 differentially expressed proteins in the BxPC3, PANC-1, and HPDE cell lines. Bioinformatics analysis identified 15 epithelial to mesenchymal transition (EMT) markers and 13 EMT-related proteins that were closely associated with drug resistance were differentially expressed. Interestingly, 8 of these proteins were involved in glutathione and cysteine/methionine metabolism. These results suggest that proteins related to the EMT and glutathione metabolism play important roles in the development of intrinsic gemcitabine resistance by pancreatic cancer cell lines.