1.Low-Dose Perifosine, a Phase II Phospholipid Akt Inhibitor, Selectively Sensitizes Drug-Resistant ABCB1-Overexpressing Cancer Cells
Jae Hyeon PARK ; Haeun LEE ; Tian ZHENG ; Joo Kyung SHIN ; Sungpil YOON ; Hyung Sik KIM
Biomolecules & Therapeutics 2025;33(1):170-181
We identified drugs or mechanisms targeting ABCB1 (or P-glycoprotein; P-gp)-overexpressing drug-resistant cancer populations, given that these cells play a key role in tumor recurrence. Specifically, we searched for Akt inhibitors that could increase cytotoxicity in P-gp-overexpressing drug-resistant cancer cells. We performed cytotoxicity assays using five cell lines: 1. MCF-7/ADR, 2. KBV20C cancer cells (P-gp overexpression, vincristine [VIC] resistance, and GSK690693-resistance), 3. MCF-7, 4. normal HaCaT cells (non-P-gp-overexpressing, VIC-sensitive, and GSK690693-sensitive), and 5. MDA-MB-231 cancer cells (non-Pgp overexpression, relatively VIC-resistance, and GSK690693-sensitive). Herein, we found that low-dose perifosine markedly and selectively sensitizes both MCF-7/ADR and KBV20C drug-resistant cancer cells exhibiting P-gp overexpression. Compared with other Akt inhibitors (AZD5363, BKM120, and GSK690693), low-dose perifosine specifically sensitized P-gp-overexpressing resistant MCF-7/ADR cancer cells. Conversely, Akt inhibitors (other than perifosine) could enhance sensitization effects in drugsensitive MCF-7 and HaCaT cells. Considering that perifosine has both an alkyl-phospholipid structure and is an allosteric inhibitor for membrane-localizing Akt-targeting, we examined structurally and functionally similar Akt inhibitors (miltefosine and MK-2206).However, we found that these inhibitors were non-specific, suggesting that the specificity of perifosine in P-gp-overexpressing resistant cancer cells is unrelated to phospholipid localizing membranes or allosteric inhibition. Furthermore, we examined the molecular mechanism of low-dose perifosine in drug-resistant MCF-7/ADR cancer cells. MCF-7/ADR cells exhibited increased apoptosis via G2 arrest and autophagy induction. However, no increase in P-gp-inhibitory activity was observed in drug-resistant MCF-7/ADR cancer cells. Single low-dose perifosine treatment exerted a sensitization effect similar to co-treatment with VIC in P-gp-overexpressing drug-resistant MCF-7/ADR cancer cells, suggesting that single treatment with low-dose perifosine is a more powerful tool against P-gp-overexpressing drug-resistant cancer cells. These findings could contribute to its clinical use as a first-line treatment, explicitly targeting P-gp-overexpressing resistant cancer populations in heterogeneous tumor populations.Therefore, perifosine may be valuable in delaying or reducing cancer recurrence by targeting P-gp-overexpressing drug-resistant cancer cells.
2.Glucagon-Like Peptide-1 and Hypothalamic Regulation of Satiation: Cognitive and Neural Insights from Human and Animal Studies
Joon Seok PARK ; Kyu Sik KIM ; Hyung Jin CHOI
Diabetes & Metabolism Journal 2025;49(3):333-347
Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have emerged as blockbuster drugs for treating metabolic diseases. Glucagon-like peptide-1 (GLP-1) plays a pivotal role in glucose homeostasis by enhancing insulin secretion, suppressing glucagon release, delaying gastric emptying, and acting on the central nervous system to regulate satiation and satiety. This review summarizes the discovery of GLP-1 and the development of GLP-1RAs, with a particular focus on their central mechanisms of action. Human neuroimaging studies demonstrate that GLP-1RAs influence brain activity during food cognition, supporting a role in pre-ingestive satiation. Animal studies on hypothalamic feed-forward regulation of hunger suggest that cognitive hypothalamic mechanisms may also contribute to satiation control. We highlight the brain mechanisms of GLP-1RA-induced satiation and satiety, including cognitive impacts, with an emphasis on animal studies of hypothalamic glucagon-like peptide-1 receptor (GLP-1R) and GLP-1R-expressing neurons. Actions in non-hypothalamic regions are also discussed. Additionally, we review emerging combination drugs and oral GLP-1RA formulations aimed at improving efficacy and patient adherence. In conclusion, the dorsomedial hypothalamus (DMH)—a key GLP-1RA target—mediates pre-ingestive cognitive satiation, while other hypothalamic GLP-1R neurons regulate diverse aspects of feeding behavior, offering potential therapeutic targets for obesity treatment.
3.Glucagon-Like Peptide-1 and Hypothalamic Regulation of Satiation: Cognitive and Neural Insights from Human and Animal Studies
Joon Seok PARK ; Kyu Sik KIM ; Hyung Jin CHOI
Diabetes & Metabolism Journal 2025;49(3):333-347
Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have emerged as blockbuster drugs for treating metabolic diseases. Glucagon-like peptide-1 (GLP-1) plays a pivotal role in glucose homeostasis by enhancing insulin secretion, suppressing glucagon release, delaying gastric emptying, and acting on the central nervous system to regulate satiation and satiety. This review summarizes the discovery of GLP-1 and the development of GLP-1RAs, with a particular focus on their central mechanisms of action. Human neuroimaging studies demonstrate that GLP-1RAs influence brain activity during food cognition, supporting a role in pre-ingestive satiation. Animal studies on hypothalamic feed-forward regulation of hunger suggest that cognitive hypothalamic mechanisms may also contribute to satiation control. We highlight the brain mechanisms of GLP-1RA-induced satiation and satiety, including cognitive impacts, with an emphasis on animal studies of hypothalamic glucagon-like peptide-1 receptor (GLP-1R) and GLP-1R-expressing neurons. Actions in non-hypothalamic regions are also discussed. Additionally, we review emerging combination drugs and oral GLP-1RA formulations aimed at improving efficacy and patient adherence. In conclusion, the dorsomedial hypothalamus (DMH)—a key GLP-1RA target—mediates pre-ingestive cognitive satiation, while other hypothalamic GLP-1R neurons regulate diverse aspects of feeding behavior, offering potential therapeutic targets for obesity treatment.
4.Low-Dose Perifosine, a Phase II Phospholipid Akt Inhibitor, Selectively Sensitizes Drug-Resistant ABCB1-Overexpressing Cancer Cells
Jae Hyeon PARK ; Haeun LEE ; Tian ZHENG ; Joo Kyung SHIN ; Sungpil YOON ; Hyung Sik KIM
Biomolecules & Therapeutics 2025;33(1):170-181
We identified drugs or mechanisms targeting ABCB1 (or P-glycoprotein; P-gp)-overexpressing drug-resistant cancer populations, given that these cells play a key role in tumor recurrence. Specifically, we searched for Akt inhibitors that could increase cytotoxicity in P-gp-overexpressing drug-resistant cancer cells. We performed cytotoxicity assays using five cell lines: 1. MCF-7/ADR, 2. KBV20C cancer cells (P-gp overexpression, vincristine [VIC] resistance, and GSK690693-resistance), 3. MCF-7, 4. normal HaCaT cells (non-P-gp-overexpressing, VIC-sensitive, and GSK690693-sensitive), and 5. MDA-MB-231 cancer cells (non-Pgp overexpression, relatively VIC-resistance, and GSK690693-sensitive). Herein, we found that low-dose perifosine markedly and selectively sensitizes both MCF-7/ADR and KBV20C drug-resistant cancer cells exhibiting P-gp overexpression. Compared with other Akt inhibitors (AZD5363, BKM120, and GSK690693), low-dose perifosine specifically sensitized P-gp-overexpressing resistant MCF-7/ADR cancer cells. Conversely, Akt inhibitors (other than perifosine) could enhance sensitization effects in drugsensitive MCF-7 and HaCaT cells. Considering that perifosine has both an alkyl-phospholipid structure and is an allosteric inhibitor for membrane-localizing Akt-targeting, we examined structurally and functionally similar Akt inhibitors (miltefosine and MK-2206).However, we found that these inhibitors were non-specific, suggesting that the specificity of perifosine in P-gp-overexpressing resistant cancer cells is unrelated to phospholipid localizing membranes or allosteric inhibition. Furthermore, we examined the molecular mechanism of low-dose perifosine in drug-resistant MCF-7/ADR cancer cells. MCF-7/ADR cells exhibited increased apoptosis via G2 arrest and autophagy induction. However, no increase in P-gp-inhibitory activity was observed in drug-resistant MCF-7/ADR cancer cells. Single low-dose perifosine treatment exerted a sensitization effect similar to co-treatment with VIC in P-gp-overexpressing drug-resistant MCF-7/ADR cancer cells, suggesting that single treatment with low-dose perifosine is a more powerful tool against P-gp-overexpressing drug-resistant cancer cells. These findings could contribute to its clinical use as a first-line treatment, explicitly targeting P-gp-overexpressing resistant cancer populations in heterogeneous tumor populations.Therefore, perifosine may be valuable in delaying or reducing cancer recurrence by targeting P-gp-overexpressing drug-resistant cancer cells.
5.Glucagon-Like Peptide-1 and Hypothalamic Regulation of Satiation: Cognitive and Neural Insights from Human and Animal Studies
Joon Seok PARK ; Kyu Sik KIM ; Hyung Jin CHOI
Diabetes & Metabolism Journal 2025;49(3):333-347
Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have emerged as blockbuster drugs for treating metabolic diseases. Glucagon-like peptide-1 (GLP-1) plays a pivotal role in glucose homeostasis by enhancing insulin secretion, suppressing glucagon release, delaying gastric emptying, and acting on the central nervous system to regulate satiation and satiety. This review summarizes the discovery of GLP-1 and the development of GLP-1RAs, with a particular focus on their central mechanisms of action. Human neuroimaging studies demonstrate that GLP-1RAs influence brain activity during food cognition, supporting a role in pre-ingestive satiation. Animal studies on hypothalamic feed-forward regulation of hunger suggest that cognitive hypothalamic mechanisms may also contribute to satiation control. We highlight the brain mechanisms of GLP-1RA-induced satiation and satiety, including cognitive impacts, with an emphasis on animal studies of hypothalamic glucagon-like peptide-1 receptor (GLP-1R) and GLP-1R-expressing neurons. Actions in non-hypothalamic regions are also discussed. Additionally, we review emerging combination drugs and oral GLP-1RA formulations aimed at improving efficacy and patient adherence. In conclusion, the dorsomedial hypothalamus (DMH)—a key GLP-1RA target—mediates pre-ingestive cognitive satiation, while other hypothalamic GLP-1R neurons regulate diverse aspects of feeding behavior, offering potential therapeutic targets for obesity treatment.
6.Low-Dose Perifosine, a Phase II Phospholipid Akt Inhibitor, Selectively Sensitizes Drug-Resistant ABCB1-Overexpressing Cancer Cells
Jae Hyeon PARK ; Haeun LEE ; Tian ZHENG ; Joo Kyung SHIN ; Sungpil YOON ; Hyung Sik KIM
Biomolecules & Therapeutics 2025;33(1):170-181
We identified drugs or mechanisms targeting ABCB1 (or P-glycoprotein; P-gp)-overexpressing drug-resistant cancer populations, given that these cells play a key role in tumor recurrence. Specifically, we searched for Akt inhibitors that could increase cytotoxicity in P-gp-overexpressing drug-resistant cancer cells. We performed cytotoxicity assays using five cell lines: 1. MCF-7/ADR, 2. KBV20C cancer cells (P-gp overexpression, vincristine [VIC] resistance, and GSK690693-resistance), 3. MCF-7, 4. normal HaCaT cells (non-P-gp-overexpressing, VIC-sensitive, and GSK690693-sensitive), and 5. MDA-MB-231 cancer cells (non-Pgp overexpression, relatively VIC-resistance, and GSK690693-sensitive). Herein, we found that low-dose perifosine markedly and selectively sensitizes both MCF-7/ADR and KBV20C drug-resistant cancer cells exhibiting P-gp overexpression. Compared with other Akt inhibitors (AZD5363, BKM120, and GSK690693), low-dose perifosine specifically sensitized P-gp-overexpressing resistant MCF-7/ADR cancer cells. Conversely, Akt inhibitors (other than perifosine) could enhance sensitization effects in drugsensitive MCF-7 and HaCaT cells. Considering that perifosine has both an alkyl-phospholipid structure and is an allosteric inhibitor for membrane-localizing Akt-targeting, we examined structurally and functionally similar Akt inhibitors (miltefosine and MK-2206).However, we found that these inhibitors were non-specific, suggesting that the specificity of perifosine in P-gp-overexpressing resistant cancer cells is unrelated to phospholipid localizing membranes or allosteric inhibition. Furthermore, we examined the molecular mechanism of low-dose perifosine in drug-resistant MCF-7/ADR cancer cells. MCF-7/ADR cells exhibited increased apoptosis via G2 arrest and autophagy induction. However, no increase in P-gp-inhibitory activity was observed in drug-resistant MCF-7/ADR cancer cells. Single low-dose perifosine treatment exerted a sensitization effect similar to co-treatment with VIC in P-gp-overexpressing drug-resistant MCF-7/ADR cancer cells, suggesting that single treatment with low-dose perifosine is a more powerful tool against P-gp-overexpressing drug-resistant cancer cells. These findings could contribute to its clinical use as a first-line treatment, explicitly targeting P-gp-overexpressing resistant cancer populations in heterogeneous tumor populations.Therefore, perifosine may be valuable in delaying or reducing cancer recurrence by targeting P-gp-overexpressing drug-resistant cancer cells.
7.Glucagon-Like Peptide-1 and Hypothalamic Regulation of Satiation: Cognitive and Neural Insights from Human and Animal Studies
Joon Seok PARK ; Kyu Sik KIM ; Hyung Jin CHOI
Diabetes & Metabolism Journal 2025;49(3):333-347
Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have emerged as blockbuster drugs for treating metabolic diseases. Glucagon-like peptide-1 (GLP-1) plays a pivotal role in glucose homeostasis by enhancing insulin secretion, suppressing glucagon release, delaying gastric emptying, and acting on the central nervous system to regulate satiation and satiety. This review summarizes the discovery of GLP-1 and the development of GLP-1RAs, with a particular focus on their central mechanisms of action. Human neuroimaging studies demonstrate that GLP-1RAs influence brain activity during food cognition, supporting a role in pre-ingestive satiation. Animal studies on hypothalamic feed-forward regulation of hunger suggest that cognitive hypothalamic mechanisms may also contribute to satiation control. We highlight the brain mechanisms of GLP-1RA-induced satiation and satiety, including cognitive impacts, with an emphasis on animal studies of hypothalamic glucagon-like peptide-1 receptor (GLP-1R) and GLP-1R-expressing neurons. Actions in non-hypothalamic regions are also discussed. Additionally, we review emerging combination drugs and oral GLP-1RA formulations aimed at improving efficacy and patient adherence. In conclusion, the dorsomedial hypothalamus (DMH)—a key GLP-1RA target—mediates pre-ingestive cognitive satiation, while other hypothalamic GLP-1R neurons regulate diverse aspects of feeding behavior, offering potential therapeutic targets for obesity treatment.
8.The prevention and response to infectious diseases in long-term care facilities in Korea: a nationwide survey
Sun Hee NA ; Joong Sik EOM ; Sun Bean KIM ; Hyung Jin YOON ; So Yeon YOO ; Kyeong Sook CHA ; Jong Rim CHOI ; Ji Youn CHOI ; Si Hyeon HAN ; Jin Ju PARK ; Tark KIM ; Jacob LEE
Epidemiology and Health 2024;46(1):e2024084-
OBJECTIVES:
Long-term care facilities (LTCFs) are communal environments for patients with chronic diseases or older adults, making them particularly susceptible to significant harm during infectious disease outbreaks. Nonetheless, LTCFs have historically been subject to less stringent infection prevention and control (IPC) mandates. This study aimed to assess the current state of LTCFs and to develop an IPC system tailored for these facilities following the coronavirus disease 2019 (COVID-19) pandemic.
METHODS:
We conducted an online survey of 11,366 LTCFs in Korea from December 30, 2022 to January 20, 2023, to evaluate the components of IPC in LTCFs. The infectious diseases targeted for IPC included COVID-19, influenza, and scabies. Additionally, we compared institution-based and home-based long-term care insurance facilities.
RESULTS:
Overall, 3,537 (31.1%) LTCFs responded to the survey, comprising 1,819 (51.4%) institution-based and 1,718 (48.6%) home-based facilities. A majority (87.4%, 2,376/2,720) of these facilities experienced COVID-19 outbreaks. However, only 42.2% of home-based facilities, in contrast to 90.6% of institution-based facilities, were equipped to manage concurrent COVID-19 cases. Similarly, while 92.1% of institution-based facilities were capable of managing influenza, only 50.5% of home-based facilities could do the same. The incidence of scabies was significantly higher in institution-based facilities than in home-based ones (26.1 vs. 4.3%). Additionally, 88.7% of institution-based facilities managed scabies cases effectively, compared to only 42.1% of home-based facilities.
CONCLUSIONS
Approximately half of the LTCFs had a basic capacity to respond to infectious diseases. However, there were differences in response capabilities between institution-based facilities and home-based facilities.
9.Contemporary Statistics of Acute Ischemic Stroke and Transient Ischemic Attack in 2021: Insights From the CRCS-K-NIH Registry
Do Yeon KIM ; Tai Hwan PARK ; Yong-Jin CHO ; Jong-Moo PARK ; Kyungbok LEE ; Minwoo LEE ; Juneyoung LEE ; Sang Yoon BAE ; Da Young HONG ; Hannah JUNG ; Eunvin KO ; Hyung Seok GUK ; Beom Joon KIM ; Jun Yup KIM ; Jihoon KANG ; Moon-Ku HAN ; Sang-Soon PARK ; Keun-Sik HONG ; Hong-Kyun PARK ; Jeong-Yoon LEE ; Byung-Chul LEE ; Kyung-Ho YU ; Mi Sun OH ; Dong-Eog KIM ; Dong-Seok GWAK ; Soo Joo LEE ; Jae Guk KIM ; Jun LEE ; Doo Hyuk KWON ; Jae-Kwan CHA ; Dae-Hyun KIM ; Joon-Tae KIM ; Kang-Ho CHOI ; Hyunsoo KIM ; Jay Chol CHOI ; Joong-Goo KIM ; Chul-Hoo KANG ; Sung-il SOHN ; Jeong-Ho HONG ; Hyungjong PARK ; Sang-Hwa LEE ; Chulho KIM ; Dong-Ick SHIN ; Kyu Sun YUM ; Kyusik KANG ; Kwang-Yeol PARK ; Hae-Bong JEONG ; Chan-Young PARK ; Keon-Joo LEE ; Jee Hyun KWON ; Wook-Joo KIM ; Ji Sung LEE ; Hee-Joon BAE ;
Journal of Korean Medical Science 2024;39(34):e278-
This report presents the latest statistics on the stroke population in South Korea, sourced from the Clinical Research Collaborations for Stroke in Korea-National Institute for Health (CRCS-K-NIH), a comprehensive, nationwide, multicenter stroke registry. The Korean cohort, unlike western populations, shows a male-to-female ratio of 1.5, attributed to lower risk factors in Korean women. The average ages for men and women are 67 and 73 years, respectively.Hypertension is the most common risk factor (67%), consistent with global trends, but there is a higher prevalence of diabetes (35%) and smoking (21%). The prevalence of atrial fibrillation (19%) is lower than in western populations, suggesting effective prevention strategies in the general population. A high incidence of large artery atherosclerosis (38%) is observed, likely due to prevalent intracranial arterial disease in East Asians and advanced imaging techniques.There has been a decrease in intravenous thrombolysis rates, from 12% in 2017–2019 to 10% in 2021, with no improvements in door-to-needle and door-to-puncture times, worsened by the coronavirus disease 2019 pandemic. While the use of aspirin plus clopidogrel for noncardioembolic stroke and direct oral anticoagulants for atrial fibrillation is well-established, the application of direct oral anticoagulants for non-atrial fibrillation cardioembolic strokes in the acute phase requires further research. The incidence of early neurological deterioration (13%) and the cumulative incidence of recurrent stroke at 3 months (3%) align with global figures. Favorable outcomes at 3 months (63%) are comparable internationally, yet the lack of improvement in dependency at 3 months highlights the need for advancements in acute stroke care.
10.Ten-year Trends in Infectious Keratitis in South Korea
Chanjoon PARK ; Hye Yeon YOON ; Young Sik YOO ; Hyun Soo LEE ; Hyung Bin HWANG ; Kyung Sun NA ; Yang Kyung CHO ; Eun Chul KIM ; So Hyang CHUNG ; Hyun Seung KIM ; Yong-Soo BYUN
Journal of the Korean Ophthalmological Society 2024;65(3):181-193
Purpose:
This study investigated the causative microorganisms, antibiotic susceptibility, and risk factors of infectious keratitis over the past 10 years.
Methods:
Data from patients with infectious keratitis who underwent microbial culture tests from 2012 to 2021, obtained from anonymized data systems, were analyzed. Microbial culture results and antibiotic susceptibility profiles were examined. A retrospective analysis of the medical records of patients with infectious keratitis during the same period was conducted to investigate the clinical characteristics and risk factors.
Results:
Data from 1,837 cases of infectious keratitis were extracted from anonymized records. The culture positive rate among patients was 46.0% (1,137/2,474), with coagulase-negative Staphylococcus (CoNS) being the most common causative organism (27.8%). Increased resistance to cefazolin and cefotaxime was observed in gram-negative bacteria, while there were no significant temporal changes in quinolone resistance in gram-positive or negative bacteria. A retrospective medical record analysis of 288 cases revealed that older patients, as well as those with an initial corrected visual acuity < 0.1, a history of ocular surgery, pre-existing ocular conditions, prior steroid eye drops, or glaucoma eye drops, had significantly higher rates of culture positivity. Multivariate analysis identified risk factors for severe keratitis requiring surgical intervention as a symptom-to-presentation period of 7 days or longer (p = 0.048) and pre-existing ocular conditions (p = 0.040).
Conclusions
CoNS was the most common microorganism causing infectious keratitis over the past decade. There has been an increase in resistance to cephalosporin antibiotics among gram-negative bacteria. Patients with pre-existing ocular conditions may require surgical intervention, so infectious keratitis in these patients requires greater attention.

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