1.Arctigenin induces caspase-dependent apoptosis in FaDu human pharyngeal carcinoma cells
Kyeong-Rok KANG ; Jae-Sung KIM ; HyangI LIM ; Jeong-Yeon SEO ; Jong-Hyun PARK ; Hong Sung CHUN ; Sun-Kyoung YU ; Heung-Joong KIM ; Chun Sung KIM ; Do Kyung KIM
The Korean Journal of Physiology and Pharmacology 2022;26(6):447-456
The present study was carried out to investigate the effect of Arctigenin on cell growth and the mechanism of cell death elicited by Arctigenin were examined in FaDu human pharyngeal carcinoma cells. To determine the apoptotic activity of Arctigenin in FaDu human pharyngeal carcinoma cells, cell viability assay, DAPI staining, caspase activation analysis, and immunoblotting were performed. Arctigenin inhibited the growth of cells in a dose-dependent manner and induced nuclear condensation and fragmentation. Arctigenin-treated cells showed caspase-3/7 activation and increased apoptosis versus control cells. FasL, a death ligand associated with extrinsic apoptotic signaling pathways, was up-regulated by Arctigenin treatment. Moreover, caspase-8, a part of the extrinsic apoptotic pathway, was activated by Arctigenin treatments. Expressions of anti-apoptotic factors such as Bcl-2 and Bcl-xL, components of the mitochondria-dependent intrinsic apoptosis pathway, significantly decreased following Arctigenin treatment. The expressions of pro-apoptotic factors such as BAX, BAD and caspase-9, and tumor suppressor -53 increased by Arctigenin treatments. In addition, Arctigenin activated caspase-3 and poly (ADP-ribose) polymerase (PARP) induced cell death. Arctigenin also inhibited the proliferation of FaDu cells by the suppression of p38, NF-κB, and Akt signaling pathways. These results suggest that Arctigenin may inhibit cell proliferation and induce apoptotic cell death in FaDu human pharyngeal carcinoma cells through both the mitochondria-mediated intrinsic pathway and the death receptormediated extrinsic pathway.
2.Long-term follow-up results of cytarabine-containing chemotherapy for acute promyelocytic leukemia
Young Hoon PARK ; Dae-Young KIM ; Yeung-Chul MUN ; Eun Kyung CHO ; Jae Hoon LEE ; Deog-Yeon JO ; Inho KIM ; Sung-Soo YOON ; Seon Yang PARK ; Byoungkook KIM ; Soo-Mee BANG ; Hawk KIM ; Young Joo MIN ; Jae Hoo PARK ; Jong Jin SEO ; Hyung Nam MOON ; Moon Hee LEE ; Chul Soo KIM ; Won Sik LEE ; So Young CHONG ; Doyeun OH ; Dae Young ZANG ; Kyung Hee LEE ; Myung Soo HYUN ; Heung Sik KIM ; Sung-Hyun KIM ; Hyukchan KWON ; Hyo Jin KIM ; Kyung Tae PARK ; Sung Hwa BAE ; Hun Mo RYOO ; Jung Hye CHOI ; Myung-Ju AHN ; Hwi-Joong YOON ; Sung-Hyun NAM ; Bong-Seog KIM ; Chu-Myong SEONG
The Korean Journal of Internal Medicine 2022;37(4):841-850
Background/Aims:
We evaluated the feasibility and long-term efficacy of the combination of cytarabine, idarubicin, and all-trans retinoic acid (ATRA) for treating patients with newly diagnosed acute promyelocytic leukemia (APL).
Methods:
We included 87 patients with newly diagnosed acute myeloid leukemia and a t(15;17) or promyelocytic leukemia/retinoic acid receptor alpha (PML-RARα) mutation. Patients received 12 mg/m2/day idarubicin intravenously for 3 days and 100 mg/m2/day cytarabine for 7 days, plus 45 mg/m2/day ATRA. Clinical outcomes included complete remission (CR), relapse-free survival (RFS), overall survival (OS), and the secondary malignancy incidence during a 20-year follow-up.
Results:
The CR, 10-year RFS, and 10-year OS rates were 89.7%, 94.1%, and 73.8%, respectively, for all patients. The 10-year OS rate was 100% for patients that achieved CR. Subjects were classified according to the white blood cell (WBC) count in peripheral blood at diagnosis (low-risk, WBC < 10,000/mm3; high-risk, WBC ≥ 10,000/mm3). The low-risk group had significantly higher RFS and OS rates than the high-risk group, but the outcomes were not superior to the current standard treatment (arsenic trioxide plus ATRA). Toxicities were similar to those observed with anthracycline plus ATRA, and higher than those observed with arsenic trioxide plus ATRA. The secondary malignancy incidence after APL treatment was 2.7%, among the 75 patients that achieved CR, and 5.0% among the 40 patients that survived more than 5 years after the APL diagnosis.
Conclusions
Adding cytarabine to anthracycline plus ATRA was not inferior to anthracycline plus ATRA alone, but it was not comparable to arsenic trioxide plus ATRA. The probability of secondary malignancy was low.
3.Nicotinamide phosphoribosyltransferase regulates the cell differentiation and mineralization in cultured odontoblasts
Kyeong-Rok KANG ; Jae-Sung KIM ; Jeong-Yeon SEO ; HyangI LIM ; Tae-Hyeon KIM ; Sun-Kyoung YU ; Heung-Joong KIM ; Chun Sung KIM ; Hong Sung CHUN ; Joo-Cheol PARK ; Do Kyung KIM
The Korean Journal of Physiology and Pharmacology 2022;26(1):37-45
The aim of the present study was to investigate the physiological role of nicotinamide phosphoribosyltransferase (NAMPT) associated with odontogenic differentiation during tooth development in mice. Mouse dental papilla cell-23 (MDPC-23) cells cultured in differentiation media were stimulated with the specific NAMPT inhibitor, FK866, and Visfatin (NAMPT) for up to 10 days. The cells were evaluated after 0, 4, 7, and 10 days. Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The mineralization assay was performed by staining MDPC-23 cells with Alizarin Red S solution. After cultivation, MDPC-23 cells were harvested for quantitative PCR or Western blotting. Analysis of variance was performed using StatView 5.0 software (SAS Institute Inc., Cary, NC, USA). Statistical significance was set at p < 0.05. The expression of NAMPT increased during the differentiation of murine odontoblast-like MDPC-23 cells. Furthermore, the up-regulation of NAMPT promoted odontogenic differentiation and accelerated mineralization through an increase in representative odontoblastic biomarkers, such as dentin sialophosphoprotein, dentin matrix protein-1, and alkaline phosphatase in MDPC-23 cells. However, treatment of the cells with the NAMPT inhibitor, FK866, attenuated odontogenic differentiation, as evidenced by the suppression of odontoblastic biomarkers. These data indicate that NAMPT regulated odontoblastic differentiation through the regulation of odontoblastic biomarkers. The increase in NAMPT expression in odontoblasts was closely related to the formation of the extracellular matrix and dentin via the Runx signaling pathway. Therefore, these data suggest that NAMPT is a critical regulator of odontoblast differentiation during tooth development.
4.Morphology of the temporalis muscle focusing on the tendinous attachment onto the coronoid process
Sun Kyoung YU ; Tae-Hoon KIM ; Kwang Yeol YANG ; Christopher J. BAE ; Heung-Joong KIM
Anatomy & Cell Biology 2021;54(3):308-314
The temporalis muscle is usually described as a single layer originating at the temporal line, converging to a tendon, and inserting onto a narrow site of the coronoid process. However, recent studies have shown that the temporalis muscle can be divided into two or three separate segments and the distal attachment continues inferiorly beyond the coronoid process. Therefore, the aims of this study were to analyze the morphology of the temporalis muscle focusing on the tendinous attachment onto the coronoid process and to provide educational values. The temporalis muscle was carefully dissected in 26 cadavers and classified based on the muscle fascicle direction. Each divided part was sketched and measured based on bony landmarks to elucidate its tendinous insertion site onto the coronoid process, and the results obtained were reviewed through the literature. The temporalis muscle ends at two distinct terminal tendons with wider insertion sites than usually presented in textbooks and atlases and separates into two parts that combine to act as a single structural unit. The superficial part is a large fan-shaped muscle commonly recognized as the temporalis muscle. This converges infero-medially to form the superficial tendon and the lateral boundary of the retromolar triangle. Meanwhile, the deep part is a narrow vertically oriented rectangular muscle that converges postero-laterally to form the deep tendon and the medial boundary of the retromolar triangle. These results indicate that understanding the temporalis muscle’s insertion site onto the coronoid process will be useful clinically with educational values during surgical procedures.
5.Apoptotic activity of demethoxycurcumin in MG-63human osteosarcoma cells
Kyeong-Rok KANG ; Jae-Sung KIM ; Tae-Hyeon KIM ; Jeong-Yeon SEO ; Jong-Hyun PARK ; Hong Sung CHUN ; Sun-Kyoung YU ; Heung-Joong KIM ; Chun Sung KIM ; Do Kyung KIM
International Journal of Oral Biology 2021;46(1):23-29
Demethoxycurcumin (DMC), which is a curcuminoid found in turmeric, has anti-proliferative effects on cancer cells. However, the effect of DMC on osteosarcoma has not been established. The aim of this study was to examine the effects of DMC on cell growth and apoptosis induction in MG-63 human osteosarcoma cells. This study was investigated using 3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyl tetrazolium bromid assay, Live/Dead cell assay, 4’, 6-diamidino-2-phenylindole staining, and immunoblotting in MG-63 cells. DMC induced MG-63 cell death in a dosedependent manner, with an estimated IC50 value of 54.4 μM. DMC treatment resulted in nuclear condensation in MG-63 cells. DMC-induced apoptosis in MG-63 cells was mediated by the expression of Fas and activation of caspase-8, caspase-3, and poly (ADP-ribose) polymerase. Immunoblotting results showed that Bcl-2 and Bcl-xL were downregulated, while Bax and Bad were upregulated by DMC in MG-63 cells. These results indicated that DMC inhibits cell proliferation and induces apoptotic cell death in MG-63 human osteosarcoma cells via the death receptormediated extrinsic apoptotic pathway and mitochondria-mediated intrinsic apoptotic pathway.
6.Alpha-lipoic acid protects human dopaminergic neuronal cells against hydrogen peroxide-induced cell injury by inhibiting autophagy and apoptosis
Kyeong-Rok KANG ; Jae-Sung KIM ; Tae-Hyeon KIM ; Jeong-Yeon SEO ; HyangI LIM ; Jong-Hyun PARK ; Kwang Yeol YANG ; Sun-Kyoung YU ; Heung-Joong KIM ; Chun Sung KIM ; Hong Sung CHUN ; Dong-Seol LEE ; Joo-Cheol PARK ; Do Kyung KIM
International Journal of Oral Biology 2021;46(1):15-22
Alpha-lipoic acid (ALA) is a naturally occurring antioxidant and has been previously used to treat diabetes and cardiovascular disease. However, the autophagy effects of ALA against oxidative stress-induced dopaminergic neuronal cell injury remain unclear. The aim of this study was to investigate the role of ALA in autophagy and apoptosis against oxidative stress in the SH-SY5Y human dopaminergic neuronal cell line. We examined SH-SY5Y phenotypes using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay (cell viability/proliferation), 4′,6-diamidino-2-phenylindole dihydrochloride nuclear staining, Live/Dead cell assay, cellular reactive oxygen species (ROS) assay, immunoblotting, and immunocytochemistry. Our data showed ALA attenuated hydrogen peroxide (H2O2)-induced ROS generation and cell death. ALA effectively suppressed Bax up-regulation and Bcl-2 and BclxL down-regulation. Furthermore, ALA increased the expression of the antioxidant enzyme, heme oxygenase-1. Moreover, the expression of Beclin-1 and LC-3 autophagy biomarkers was decreased by ALA in our cell model. Combined, these data suggest ALA protects human dopaminergic neuronal cells against H2O2-induced cell injury by inhibiting autophagy and apoptosis.
7.Clinical Outcomes Following Letrozole Treatment according to Estrogen Receptor Expression in Postmenopausal Women: LETTER Study (KBCSG-006)
Sung Gwe AHN ; Seok Jin NAM ; Sei Hyun AHN ; Yongsik JUNG ; Heung Kyu PARK ; Soo Jung LEE ; Sung Soo KANG ; Wonshik HAN ; Kyong Hwa PARK ; Yong Lai PARK ; Jihyoun LEE ; Hyun Jo YOUN ; Jun Hyun KIM ; Youngbum YOO ; Jeong-Yoon SONG ; Byung Kyun KO ; Geumhee GWAK ; Min Sung CHUNG ; Sung Yong KIM ; Seo Heon CHO ; Doyil KIM ; Myung-Chul CHANG ; Byung In MOON ; Lee Su KIM ; Sei Joong KIM ; Min Ho PARK ; Tae Hyun KIM ; Jihyoung CHO ; Cheol Wan LIM ; Young Tae BAE ; Gyungyub GONG ; Young Kyung BAE ; Ahwon LEE ; Joon JEONG
Journal of Breast Cancer 2021;24(2):164-174
Purpose:
In this trial, we investigated the efficacy and safety of adjuvant letrozole for hormone receptor (HR)-positive breast cancer. Here, we report the clinical outcome in postmenopausal women with HR-positive breast cancer treated with adjuvant letrozole according to estrogen receptor (ER) expression levels.
Methods:
In this multi-institutional, open-label, observational study, postmenopausal patients with HR-positive breast cancer received adjuvant letrozole (2.5 mg/daily) for 5 years unless they experienced disease progression or unacceptable toxicity or withdrew their consent. The patients were stratified into the following 3 groups according to ER expression levels using a modified Allred score (AS): low, intermediate, and high (AS 3–4, 5–6, and 7–8, respectively). ER expression was centrally reviewed. The primary objective was the 5-year disease-free survival (DFS) rate.
Results:
Between April 25, 2010, and February 5, 2014, 440 patients were enrolled. With a median follow-up of 62.0 months, the 5-year DFS rate in all patients was 94.2% (95% confidence interval [CI], 91.8–96.6). The 5-year DFS and recurrence-free survival (RFS) rates did not differ according to ER expression; the 5-year DFS rates were 94.3% and 94.1%in the low-to-intermediate and high expression groups, respectively (p = 0.6), and the corresponding 5-year RFS rates were 95.7% and 95.4%, respectively (p = 0.7). Furthermore, 25 patients discontinued letrozole because of drug toxicity.
Conclusion
Treatment with adjuvant letrozole showed very favorable treatment outcomes and good tolerability among Korean postmenopausal women with ER-positive breast cancer, independent of ER expression.
8.Apoptotic activity of demethoxycurcumin in MG-63human osteosarcoma cells
Kyeong-Rok KANG ; Jae-Sung KIM ; Tae-Hyeon KIM ; Jeong-Yeon SEO ; Jong-Hyun PARK ; Hong Sung CHUN ; Sun-Kyoung YU ; Heung-Joong KIM ; Chun Sung KIM ; Do Kyung KIM
International Journal of Oral Biology 2021;46(1):23-29
Demethoxycurcumin (DMC), which is a curcuminoid found in turmeric, has anti-proliferative effects on cancer cells. However, the effect of DMC on osteosarcoma has not been established. The aim of this study was to examine the effects of DMC on cell growth and apoptosis induction in MG-63 human osteosarcoma cells. This study was investigated using 3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyl tetrazolium bromid assay, Live/Dead cell assay, 4’, 6-diamidino-2-phenylindole staining, and immunoblotting in MG-63 cells. DMC induced MG-63 cell death in a dosedependent manner, with an estimated IC50 value of 54.4 μM. DMC treatment resulted in nuclear condensation in MG-63 cells. DMC-induced apoptosis in MG-63 cells was mediated by the expression of Fas and activation of caspase-8, caspase-3, and poly (ADP-ribose) polymerase. Immunoblotting results showed that Bcl-2 and Bcl-xL were downregulated, while Bax and Bad were upregulated by DMC in MG-63 cells. These results indicated that DMC inhibits cell proliferation and induces apoptotic cell death in MG-63 human osteosarcoma cells via the death receptormediated extrinsic apoptotic pathway and mitochondria-mediated intrinsic apoptotic pathway.
9.Alpha-lipoic acid protects human dopaminergic neuronal cells against hydrogen peroxide-induced cell injury by inhibiting autophagy and apoptosis
Kyeong-Rok KANG ; Jae-Sung KIM ; Tae-Hyeon KIM ; Jeong-Yeon SEO ; HyangI LIM ; Jong-Hyun PARK ; Kwang Yeol YANG ; Sun-Kyoung YU ; Heung-Joong KIM ; Chun Sung KIM ; Hong Sung CHUN ; Dong-Seol LEE ; Joo-Cheol PARK ; Do Kyung KIM
International Journal of Oral Biology 2021;46(1):15-22
Alpha-lipoic acid (ALA) is a naturally occurring antioxidant and has been previously used to treat diabetes and cardiovascular disease. However, the autophagy effects of ALA against oxidative stress-induced dopaminergic neuronal cell injury remain unclear. The aim of this study was to investigate the role of ALA in autophagy and apoptosis against oxidative stress in the SH-SY5Y human dopaminergic neuronal cell line. We examined SH-SY5Y phenotypes using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay (cell viability/proliferation), 4′,6-diamidino-2-phenylindole dihydrochloride nuclear staining, Live/Dead cell assay, cellular reactive oxygen species (ROS) assay, immunoblotting, and immunocytochemistry. Our data showed ALA attenuated hydrogen peroxide (H2O2)-induced ROS generation and cell death. ALA effectively suppressed Bax up-regulation and Bcl-2 and BclxL down-regulation. Furthermore, ALA increased the expression of the antioxidant enzyme, heme oxygenase-1. Moreover, the expression of Beclin-1 and LC-3 autophagy biomarkers was decreased by ALA in our cell model. Combined, these data suggest ALA protects human dopaminergic neuronal cells against H2O2-induced cell injury by inhibiting autophagy and apoptosis.
10.Clinical Outcomes Following Letrozole Treatment according to Estrogen Receptor Expression in Postmenopausal Women: LETTER Study (KBCSG-006)
Sung Gwe AHN ; Seok Jin NAM ; Sei Hyun AHN ; Yongsik JUNG ; Heung Kyu PARK ; Soo Jung LEE ; Sung Soo KANG ; Wonshik HAN ; Kyong Hwa PARK ; Yong Lai PARK ; Jihyoun LEE ; Hyun Jo YOUN ; Jun Hyun KIM ; Youngbum YOO ; Jeong-Yoon SONG ; Byung Kyun KO ; Geumhee GWAK ; Min Sung CHUNG ; Sung Yong KIM ; Seo Heon CHO ; Doyil KIM ; Myung-Chul CHANG ; Byung In MOON ; Lee Su KIM ; Sei Joong KIM ; Min Ho PARK ; Tae Hyun KIM ; Jihyoung CHO ; Cheol Wan LIM ; Young Tae BAE ; Gyungyub GONG ; Young Kyung BAE ; Ahwon LEE ; Joon JEONG
Journal of Breast Cancer 2021;24(2):164-174
Purpose:
In this trial, we investigated the efficacy and safety of adjuvant letrozole for hormone receptor (HR)-positive breast cancer. Here, we report the clinical outcome in postmenopausal women with HR-positive breast cancer treated with adjuvant letrozole according to estrogen receptor (ER) expression levels.
Methods:
In this multi-institutional, open-label, observational study, postmenopausal patients with HR-positive breast cancer received adjuvant letrozole (2.5 mg/daily) for 5 years unless they experienced disease progression or unacceptable toxicity or withdrew their consent. The patients were stratified into the following 3 groups according to ER expression levels using a modified Allred score (AS): low, intermediate, and high (AS 3–4, 5–6, and 7–8, respectively). ER expression was centrally reviewed. The primary objective was the 5-year disease-free survival (DFS) rate.
Results:
Between April 25, 2010, and February 5, 2014, 440 patients were enrolled. With a median follow-up of 62.0 months, the 5-year DFS rate in all patients was 94.2% (95% confidence interval [CI], 91.8–96.6). The 5-year DFS and recurrence-free survival (RFS) rates did not differ according to ER expression; the 5-year DFS rates were 94.3% and 94.1%in the low-to-intermediate and high expression groups, respectively (p = 0.6), and the corresponding 5-year RFS rates were 95.7% and 95.4%, respectively (p = 0.7). Furthermore, 25 patients discontinued letrozole because of drug toxicity.
Conclusion
Treatment with adjuvant letrozole showed very favorable treatment outcomes and good tolerability among Korean postmenopausal women with ER-positive breast cancer, independent of ER expression.

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