24 results on '"Tai C. Chen"'
Search Results
2. MART-10, a 1α,25(OH)2D3 Analog, Potently Represses Metastasis of ER+ Breast Cancer Cells with VEGF-A Overexpression
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Masashi Takano, Sheng-Fong Kuo, Chun-Nan Yeh, Horng-Heng Juang, Atsushi Kittaka, Jong-Hwei S. Pang, Li-Wei Chen, Kun-Chun Chiang, Tai C. Chen, Ta-Sen Yeh, and Ming-Huang Chen
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Cancer Research ,030219 obstetrics & reproductive medicine ,Angiogenesis ,Chemistry ,Cell migration ,General Medicine ,medicine.disease ,Metastasis ,03 medical and health sciences ,0302 clinical medicine ,Breast cancer ,Oncology ,MCF-7 ,Neuropilin 1 ,Cancer cell ,medicine ,Cancer research ,030212 general & internal medicine ,Autocrine signalling - Abstract
Background Breast cancer ranks second in the list of cancer-related deaths for women. Even under multidisciplinary treatment, 25-50% of patients with breast cancer still ultimately develop metastasis, leading to poor prognosis. In addition to inducing angiogenesis, vascular endothelial growth factor-A (VEGF-A) is believed to directly increase cancer cell metastatic potential and overexpression of VEGF-A is associated with higher invasiveness of breast cancer. 1α,25(OH)2D3, the active form of vitamin D, and its analogs have been widely applied as anticancer agents in the past. Material and methods Western blot, migration and invasion assays, enzyme-linked immunosorbent assay, and immunofluorescent stain were applied in this study. Result VEGF-A increased cell migration and invasion in estrogen receptor-positive (ER+) breast cancer MCF-7 cells. VEGF-A induced an autocrine loop in MCF-7 cells as VEGF-A treatment increased both VEGF-A expression and secretion. The expression of VEGF receptor type 2 (VEGFR2) and neuropilin 1 was also up-regulated by VEGF-A in MCF-7 cells. In addition, F-actin synthesis and LIM domain kinase 1 (LIMK-1) phosphorylation were increased by VEGF-A. VEGF-A also increased β-catenin expression and nuclear translocation of both β-catenin and nuclear factor-ĸB (NF-ĸB), indicating increased β-catenin and NF-ĸB activity. 1α,25(OH)2D3 and MART-10, an analog of 1α,25(OH)2D3, effectively repressed VEGF-A-induced MCF-7 cell migration and invasion and other VEGF-A-induced effects on MCF-7 cells, with MART-10 being more potent than 1α,25(OH)2D3 Conclusion: MART-10 can be deemed as a promising agent for prevention and treatment of metastasis of ER+ breast cancer with VEGF-A overexpression.
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- 2018
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3. ASSESSMENT OF SERUM 25-HYDROXYVITAMIN D CONCENTRATIONS IN TWO COLLECTIONS OF CAPTIVE GORILLAS (GORILLA GORILLA GORILLA)
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Eric J. Baitchman, Michael F. Tlusty, Tai C. Chen, Michael F. Holick, Hayley Murphy, and Susan L. Bartlett
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Male ,Vitamin ,040301 veterinary sciences ,Gorilla ,030204 cardiovascular system & hematology ,0403 veterinary science ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Animal science ,biology.animal ,Vitamin D and neurology ,Animals ,Primate ,Vitamin D ,Serum 25 hydroxyvitamin d ,Management practices ,Gorilla gorilla ,General Veterinary ,biology ,Ecology ,04 agricultural and veterinary sciences ,General Medicine ,Animal husbandry ,Housing, Animal ,chemistry ,Animals, Zoo ,Female ,Animal Science and Zoology ,Cholecalciferol - Abstract
Serum 25-hydroxyvitamin D concentrations were assessed in subadult to adult captive lowland gorillas (Gorilla gorilla gorilla) (n = 26) at two institutions with different husbandry and management practices. Serum 25-hydroxyvitamin D (25[OH]D) concentrations for gorillas managed predominantly indoors was low (14.2 ± 5.9 ng/ml), despite consuming commercial biscuits fortified with vitamin D3. Concentrations of 25(OH)D in gorillas with near daily outdoor access were significantly higher than gorillas managed indoors, although many individuals still had serum values below concentrations recommended for adult humans. Consideration should be given to assessing 25(OH)D concentrations in all captive gorillas and providing specific supplementation, particularly to juveniles without access to direct sunlight.
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- 2017
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4. HEALTH AND NUTRITIONAL ASSESSMENT OF FREE-RANGING EASTERN INDIGO SNAKES (DRYMARCHON COUPERI) IN GEORGIA, UNITED STATES
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Natalie L. Hyslop, Mark A. Mitchell, Terry M. Norton, Carolyn Cray, Stephen J. Divers, Marcie Oliva, Ellen S. Dierenfeld, Tai C. Chen, Nancy L. Stedman, Lance A. Durden, Samantha E. J. Gibbs, Robert H. Poppenga, Dirk J. Stevenson, and S. Emmanuelle Knafo
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Blood Glucose ,Male ,0106 biological sciences ,Veterinary medicine ,Georgia ,040301 veterinary sciences ,Endangered species ,Nutritional Status ,Animals, Wild ,Biology ,010603 evolutionary biology ,01 natural sciences ,0403 veterinary science ,Electrolytes ,Reference Values ,Animals ,Aspartate Aminotransferases ,Animal nutrition ,General Veterinary ,Alanine Transaminase ,Snakes ,04 agricultural and veterinary sciences ,General Medicine ,Pesticide ,Total dissolved solids ,Uric Acid ,Cross-Sectional Studies ,Fat-Soluble Vitamin ,Parasitology ,Blood chemistry ,Threatened species ,Female ,Serum Globulins ,Animal Science and Zoology ,Animal Distribution - Abstract
Clinical pathology and nutritional parameters are useful in evaluating and monitoring threatened and endangered wildlife populations, but reference ranges for most snake species are lacking. From 2001 to 2005, health assessments were performed on 58 eastern indigo snakes (EIS) (Drymarchon couperi) captured in the wild in southeastern Georgia, United States. Health and nutritional assessments performed included hematology, serum biochemistry, fat-soluble vitamins, heavy metals, pesticide contaminants, parasitology, and surveys of other pathogens. Significant differences in total solids, packed cell volume, glucose, blood urea nitrogen, albumin : globulin ratio, amylase, triglycerides, and bile acids between males and females were observed. Additionally, there was a significant difference between liver and kidney concentrations for vitamins A and E. As previously noted in captive EIS, total Ca was elevated in comparison to concentrations reported in other snake species. Parasitism was a common finding in sampled EIS, but the overall health status of this free-ranging population appeared good. A winter-time dermatitis was found in most snakes, which resolved in the summer months. This study represents the first health and nutritional assessment of free-ranging EIS, and provides needed data to guide monitoring and conservation efforts.
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- 2016
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5. MART-10, a 1α,25(OH)
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Kun-Chun, Chiang, Chun-Nan, Yeh, Ta-Sen, Yeh, Horng-Heng, Juang, Li-Wei, Chen, Sheng-Fong, Kuo, Ming-Huang, Chen, Tai C, Chen, Masashi, Takano, Atsushi, Kittaka, and Jong-Hwei S, Pang
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Vascular Endothelial Growth Factor A ,Blotting, Western ,Fluorescent Antibody Technique ,Lim Kinases ,Antineoplastic Agents ,Breast Neoplasms ,Enzyme-Linked Immunosorbent Assay ,Vascular Endothelial Growth Factor Receptor-2 ,Neuropilin-1 ,Receptors, Estrogen ,MCF-7 Cells ,Humans ,Female ,Neoplasm Metastasis ,Cholecalciferol - Abstract
Breast cancer ranks second in the list of cancer-related deaths for women. Even under multidisciplinary treatment, 25-50% of patients with breast cancer still ultimately develop metastasis, leading to poor prognosis. In addition to inducing angiogenesis, vascular endothelial growth factor-A (VEGF-A) is believed to directly increase cancer cell metastatic potential and overexpression of VEGF-A is associated with higher invasiveness of breast cancer. 1α,25(OH)Western blot, migration and invasion assays, enzyme-linked immunosorbent assay, and immunofluorescent stain were applied in this study.VEGF-A increased cell migration and invasion in estrogen receptor-positive (ER+) breast cancer MCF-7 cells. VEGF-A induced an autocrine loop in MCF-7 cells as VEGF-A treatment increased both VEGF-A expression and secretion. The expression of VEGF receptor type 2 (VEGFR2) and neuropilin 1 was also up-regulated by VEGF-A in MCF-7 cells. In addition, F-actin synthesis and LIM domain kinase 1 (LIMK-1) phosphorylation were increased by VEGF-A. VEGF-A also increased β-catenin expression and nuclear translocation of both β-catenin and nuclear factor-ĸB (NF-ĸB), indicating increased β-catenin and NF-ĸB activity. 1α,25(OH)
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- 2018
6. MART-10, the vitamin D analog, is a potent drug to inhibit anaplastic thyroid cancer cell metastatic potential
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Masashi Takano, Kun-Chun Chiang, Chih-Hung Chen, Chun-Nan Yeh, Sheng-Fong Kuo, Atsushi Kittaka, Horng-Heng Juang, Li-Wei Chen, Shu-Fu Lin, Jen-Der Lin, Tai C. Chen, Jong-Hwei S. Pang, and Soh-Ching Ng
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Cancer Research ,medicine.medical_specialty ,Epithelial-Mesenchymal Transition ,Cell ,Antineoplastic Agents ,Metastasis ,chemistry.chemical_compound ,Downregulation and upregulation ,Cell Movement ,Cell Line, Tumor ,Internal medicine ,medicine ,Vitamin D and neurology ,Humans ,Thyroid Neoplasms ,Epithelial–mesenchymal transition ,Neoplasm Metastasis ,Anaplastic thyroid cancer ,Cholecalciferol ,business.industry ,Cancer ,medicine.disease ,Actins ,medicine.anatomical_structure ,Endocrinology ,Matrix Metalloproteinase 9 ,Oncology ,chemistry ,Cancer research ,Matrix Metalloproteinase 2 ,Drug Screening Assays, Antitumor ,business - Abstract
The survival rate of anaplastic thyroid cancer (ATC) is still very poor due to its fast growth and high metastatic potential. Currently, no effective treatment is available. The active form of vitamin D3, 1α,25(OH)2D3, has been shown to have a anti-metastatic effect in pre-clinical studies, however induction of hypercalcemia hampered its clinical application. The new class of less-calcemic vitamin D analog, 19-nor-2α-(3-hydroxypropyl)-1α,25-dihydroxyvitamin D3 (MART-10), is much more potent than 1α,25(OH)2D3 to repress cancer growth and metastasis in a variety of cancers. In this study, we demonstrated that both 1α,25(OH)2D3 and MART-10 could effectively inhibit the migration and invasion of ATC cells, 8305C and 8505C, with MART-10 much more potent than 1α,25(OH)2D3. The anti-metastatic effect of 1α,25(OH)2D3 and MART-10 on ATC cells is mediated by reversal of cadherin switch (upregulation of E-cadherin and downregulation of N-cadherin), which led to the attenuation of EMT process, and decrease of F-actin formation. We further showed that the expressions of Slug, the EMT-related transcriptional factor, and MMP-9 were inhibited by 1α,25(OH)2D3 and MART-10 in 8505C cells, but not in 8303C cells. Since metastasis is the important cause of ATC-related death, our results strongly encourage the further in vivo study of MART-10 application against ATC.
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- 2015
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7. 19-Norvitamin D analogs for breast cancer therapy
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Tai C. Chen, Atsushi Kittaka, and Yotaro Matsumoto
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medicine.medical_specialty ,Calcitriol ,Physiology ,Breast Neoplasms ,Calcitriol receptor ,chemistry.chemical_compound ,Breast cancer ,CYP24A1 ,Cell Line, Tumor ,Physiology (medical) ,Internal medicine ,medicine ,Animals ,Humans ,Cholecalciferol ,Pharmacology ,Chemistry ,Cancer ,General Medicine ,medicine.disease ,Endocrinology ,Cancer cell ,Cancer research ,Receptors, Calcitriol ,Female ,Liver cancer ,medicine.drug - Abstract
The active form of vitamin D3, 1α,25-dihydroxyvitamin D3(1α,25(OH)2D3or calcitriol), is known to inhibit the proliferation and invasiveness of many types of cancer cells, including breast, colon, pancreatic, prostate, and liver cancer cells. These findings support the use of 1α,25(OH)2D3for the treatment of these types of cancer. However, 1α,25(OH)2D3can cause hypercalcemia, so analogs of 1α,25(OH)2D3that are less calcemic but exhibit more potent anti-tumor activity would be good candidates as therapeutic agents. Therefore, a series of 19-norvitamin D analogs, in which the methylidene group on C19 is replaced with 2 hydrogen atoms, have been synthesized by several laboratories. In our laboratory, we have designed and synthesized a series of 2α-functional group substituted 19-norvitamin D3analogs and examined their anti-proliferative activity. Among them, 2α- and 2β-(3-hydroxypropyl)-1α,25-dihydroxy-19-norvitamin D3(MART-10 and MART-11) were found to be the most promising. Here, we review the rationale and approaches for the synthesis of different 19-norvitamin D analogs, and the pre-clinical studies using these analogs in breast cancer cells, in particular, we chose MART-10 for its potential application to the prevention and treatment of breast cancer.
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- 2015
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8. Synthesis and metabolic studies of 1α,2α,25-, 1α,4α,25- and 1α,4β,25-trihydroxyvitamin D3
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G. Satyanarayana Reddy, Daisuke Sawada, Masashi Takano, Miyu Nishikawa, Tai C. Chen, Kaori Yasuda, Kyohei Horie, Atsushi Kittaka, Ken Ichiro Takagi, Akiko Takeuchi, and Toshiyuki Sakaki
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Vitamin ,Glucuronate ,Stereochemistry ,Endocrinology, Diabetes and Metabolism ,Metabolite ,Clinical Biochemistry ,Biochemistry ,Calcitriol receptor ,chemistry.chemical_compound ,Endocrinology ,Calcitriol ,CYP24A1 ,Vitamin D and neurology ,Animals ,Humans ,Molecular Biology ,Molecular Structure ,Stereoisomerism ,Biological activity ,Vitamins ,Cell Biology ,Metabolism ,Rats ,chemistry ,Molecular Medicine - Abstract
Three different A-ring perhydroxylated trihydroxyvitamin D3 metabolites were synthesized from their appropriate A-ring precursors and CD-ring for their potential therapeutic applications. We first chemically synthesized 1α,2α,25-trihydroxyvitamin D3 [1α,2α,25(OH)3D3] to study its VDR binding affinity because this metabolite is a product of recombinant human CYP3A4 catalysis when 2α-(3-hydroxypropoxy)-1α,25-dihydroxyvitamin D3 (O2C3), a more potent vitamin D receptor (VDR) binder than 1α,25-dihydroxyvitamin D3 [1α,25(OH)2D3], is used as the substrate. We found that this metabolite retained 27.3% of the VDR binding affinity compared to 1α,25(OH)2D3. The kcat/Km value of CYP24A1 for 1α,2α,25(OH)3D3 is 60% of that for 1α,25(OH)2D3. Since the biological activity and the metabolic fate of a naturally occurring C4-hydroxylated vitamin D2 metabolite found in the serum of rats treated with pharmacological doses of vitamin D2 have never been described, we next synthesized 1α,4α,25-trihydroxyvitamin D3 and its diastereoisomer, 1α,4β,25-trihydroxyvitamin D3, to study their metabolism and biological activities. Both 4-hydroxylated isomers showed weaker VDR binding affinity than 1α,25(OH)2D3. Although either 4-hydroxylated isomer can be metabolized by CYP24A1 almost at the same level as 1α,25(OH)2D3, their metabolic patterns catalyzed by uridine 5'-diphosphoglucuronosyltransferase (UGT) are different; only the 4α-hydroxylated analog can be metabolized by UGT to produce a glucuronate conjugate. The results provide important information for the synthesis of new novel chemotherapeutic vitamin D analogs which would be less subjective to degradation and therefore more bioavailable than 1α,25(OH)2D3. This article is part of a Special Issue entitled '17th Vitamin D Workshop'.
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- 2015
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9. 1α,25(OH)2D3 Analog, MART-10, Inhibits Neuroendocrine Tumor Cell Metastasis After VEGF-A Stimulation
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Chun-Nan Yeh, Horng-Heng Juang, Atsushi Kittaka, Tai C. Chen, Kun-Chun Chiang, Jong-Hwei S. Pang, Jun-Te Hsu, Po-Jen Hsieh, Ta-Sen Yeh, Sheng-Fong Kuo, Li-Wei Chen, and Masashi Takano
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0301 basic medicine ,Cancer Research ,biology ,medicine.diagnostic_test ,Angiogenesis ,Chemistry ,Cell ,Cell migration ,General Medicine ,Neuroendocrine tumors ,medicine.disease ,Metastasis ,Fibronectin ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,medicine.anatomical_structure ,Oncology ,Western blot ,030220 oncology & carcinogenesis ,Neuropilin 1 ,medicine ,biology.protein ,Cancer research - Abstract
AIMS Pancreatic neuroendocrine tumors (PanNETs) are usually diagnosed in an advanced stage. Most patients with PanNETs die of metastasis. Vascular endothelial growth factor-A (VEGF-A) is a strong stimulator of angiogenesis and tumor metastasis. We aimed to investigate the effect of MART-10 [19-nor-2α-(3-hydroxypropyl)-1α,25(OH)2D3], a 1α,25-dihydroxy-vitamin D3 (1α,25(OH)2D3) analog, on PanNET cell metastasis after VEGF-A stimulation. MATERIALS AND METHODS Migration and invasion assays, western blot, and immunofluorescent staining were applied in this study. RESULTS VEGF-A increased PanNET cell migration and invasion, which was attenuated by 1α,25(OH)2D3 and MART-10. VEGF-A treatment stimulated epithelial-mesenchymal transition (EMT) of PanNET cells. During this process, expression of snail family transcriptional repressor 1 and 2, and fibronectin was up-regulated. 1α,25(OH)2D3 and MART-10 counteracted VEGF-A-induced EMT. In addition, expression of neuropilin 1, a key protein in VEGF-A signaling, was down-regulated by 1α,25(OH)2D3 and MART-10. Furthermore, synthesis of F-actin was increased by VEGF-A and reduced by 1α,25(OH)2D3 and MART-10. CONCLUSION Our data indicate that MART-10 could be deemed a promising drug for PanNET treatment.
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- 2017
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10. 1α,25(OH)
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Kun-Chun, Chiang, Chun-Nan, Yeh, Jong-Hwei S, Pang, Jun-Te, Hsu, Ta-Sen, Yeh, Li-Wei, Chen, Sheng-Fong, Kuo, Masashi, Takano, Tai C, Chen, Atsushi, Kittaka, Po-Jen, Hsieh, and Horng-Heng, Juang
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Gene Expression Regulation, Neoplastic ,Vascular Endothelial Growth Factor A ,Cell Movement ,Tumor Cells, Cultured ,Animals ,Apoptosis ,Insulinoma ,Cell Proliferation ,Cholecalciferol ,Rats - Abstract
Pancreatic neuroendocrine tumors (PanNETs) are usually diagnosed in an advanced stage. Most patients with PanNETs die of metastasis. Vascular endothelial growth factor-A (VEGF-A) is a strong stimulator of angiogenesis and tumor metastasis. We aimed to investigate the effect of MART-10 [19-nor-2α-(3-hydroxypropyl)-1α,25(OH)Migration and invasion assays, western blot, and immunofluorescent staining were applied in this study.VEGF-A increased PanNET cell migration and invasion, which was attenuated by 1α,25(OH)Our data indicate that MART-10 could be deemed a promising drug for PanNET treatment.
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- 2017
11. MART-10 represses cholangiocarcinoma cell growth and high vitamin D receptor expression indicates better prognosis for cholangiocarcinoma
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Yu Chan Chang, Kun Chun Chiang, Cheng Cheng Huang, Jong-Hwei S. Pang, Atsushi Kittaka, Chi-Tung Cheng, Tai C. Chen, Michael Hsiao, Chun Nan Yeh, Horng-Heng Juang, Ta Sen Yeh, Jun-Te Hsu, and Masashi Takano
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Male ,0301 basic medicine ,Kaplan-Meier Estimate ,Mice, SCID ,Calcitriol receptor ,Article ,Cholangiocarcinoma ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Downregulation and upregulation ,Mice, Inbred NOD ,Cell Line, Tumor ,Vitamin D and neurology ,Animals ,Humans ,Cyclin D3 ,neoplasms ,Aged ,Cell Proliferation ,Cholecalciferol ,Mice, Knockout ,Multidisciplinary ,integumentary system ,biology ,Cell growth ,Middle Aged ,Prognosis ,Xenograft Model Antitumor Assays ,030104 developmental biology ,Bile Duct Neoplasms ,chemistry ,Cell culture ,Gene Knockdown Techniques ,030220 oncology & carcinogenesis ,Cancer research ,biology.protein ,Receptors, Calcitriol ,Female ,Cyclin-dependent kinase 6 ,Growth inhibition - Abstract
Cholangiocarcinoma (CCA) is a devastating disease due to no effective treatments available. Since the non-mineral functions of vitamin D emerges, 1α,25(OH)2D3, the active form of vitamin D, has been applied in anti-cancer researches. In this study, we demonstrated that both the 1α,25(OH)2D3 analog, MART-10, and 1α,25(OH)2D3 possessed anti-growth effect on human CCA cells with MART-10 much more potent than 1α,25(OH)2D3. The growth inhibition of both drugs were mediated by induction of G0/G1 cell cycle arrest through upregulation of p27 and downregulation of CDK4, CDK6, and cyclin D3. Human neutrophil gelatinase associated lipocalin (NGAL) was found to be involved in 1α,25(OH)2D3 and MART-10 meditated growth inhibition for CCA as knockdown of NGAL decreased Ki-67 expression in SNU308 cells and rendered SNU308 cells less responsive to 1α,25(OH)2D3 and MART-10 treatment. Vitamin D receptor (VDR) knockdown partly abolished MART-10-induced inhibition of NGAL and cell growth in SNU308 cells. The xenograft animal study demonstrated MART-10 could effectively repressed CCA growth in vivo without inducing obvious side effects. The IHC examination of human CCA specimen for VDR revealed that higher VDR expression was linked with better prognosis. Collectively, our results suggest that MART-10 could be a promising regimen for CCA treatment.
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- 2017
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12. Clinical and Environmental Correlates of Serum BDNF: A descriptive study with plausible implications for AD research
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Faisal Rahman, Galit Weinstein, Sarah R. Preis, Tai C. Chen, Ramachandran S. Vasan, Bernhard M. Kaess, Sudha Seshadri, Claudia L. Satizabal, Emelia J. Benjamin, and Alexa S. Beiser
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0301 basic medicine ,Adult ,Male ,Cross-sectional study ,Offspring ,Physiology ,Enzyme-Linked Immunosorbent Assay ,Disease ,Article ,Cohort Studies ,03 medical and health sciences ,Basal (phylogenetics) ,0302 clinical medicine ,Framingham Heart Study ,Alzheimer Disease ,Humans ,Homocysteine ,Brain-derived neurotrophic factor ,Psychiatric Status Rating Scales ,Tumor Necrosis Factor-alpha ,Brain-Derived Neurotrophic Factor ,Middle Aged ,030104 developmental biology ,C-Reactive Protein ,Cross-Sectional Studies ,Neurology ,Cohort ,Linear Models ,Female ,Neurology (clinical) ,Psychology ,Neuroscience ,030217 neurology & neurosurgery ,Cohort study - Abstract
Background: Brain derived neurotrophic factor (BDNF) may play a central role in the pathogenesis of Alzheimer's disease (AD) through neurotrophic effects on basal cholinergic neurons. Reduced serum levels of BDND are observed among AD patients and may predict AD risk. Nevertheless, knowledge about factors associated with its levels in blood is lacking. Objective: To identify clinical and demographic correlates of serum BDNF levels. Methods: BDNF was measured from serum collected between 1992-1996 and 1998-2001 in participants from the Original and Offspring cohorts of the Framingham Study, respectively. A cross-sectional analysis was done to evaluate the relationship between clinical measures and BDNF levels using standard linear regression and stepwise models. Analyses were conducted in the total sample and separately in each cohort, and were adjusted for age and sex. Results: BDNF was measured in 3,689 participants (mean age 65 years, 56% women; 82% Offspring). Cigarette smoking and high total cholesterol were associated with elevated BDNF levels, and history of atrial fibrillation was associated with decreased levels. Elevated BDNF levels were related to greater physical activity and lower Tumor Necrosis Factor-α levels in Offspring. Stepwise models also revealed associations with statin use, alcohol consumption and Apolipoprotein Ee4 genotype. Conclusion: Serum BDNF correlates with various metabolic, inflammatory and life-style measures which in turn have been linked with risk of AD. Future studies of serum BDNF should adjust for these correlates and are needed to further explore the underlying interplay between BDNF and other factors in the pathophysiology of cognitive impairment and AD.
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- 2017
13. 25(OH)D Is Effective to Repress Human Cholangiocarcinoma Cell Growth through the Conversion of 25(OH)D to 1α,25(OH)₂D₃
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Kun-Chun, Chiang, Chun-Nan, Yeh, Cheng-Cheng, Huang, Ta-Sen, Yeh, Jong-Hwei, S Pang, Jun-Te, Hsu, Li-Wei, Chen, Sheng-Fong, Kuo, Atsushi, Kittaka, Tai C, Chen, and Horng-Heng, Juang
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25-Hydroxyvitamin D3 1-alpha-Hydroxylase ,Male ,Mice, Inbred BALB C ,25(OH)D ,1α-OHase ,Mice, Nude ,vitamin D ,Immunohistochemistry ,Xenograft Model Antitumor Assays ,Article ,Cholangiocarcinoma ,Mice ,Calcitriol ,CYP27B1 ,Cell Line, Tumor ,Animals ,Humans ,Cell Proliferation - Abstract
Cholangiocarcinoma (CCA) is a devastating disease without effective treatments. 1α,25(OH)2D3, the active form of Vitamin D, has emerged as a new anti-cancer regimen. However, the side effect of hypercalcemia impedes its systemic administration. 25(OH)D is biologically inert and needs hydroxylation by CYP27B1 to form 1α,25(OH)2D3, which is originally believed to only take place in kidneys. Recently, the extra-renal expression of CYP27B1 has been identified and in vitro conversion of 25(OH)D to 1α,25(OH)2D3 has been found in some cancer cells with CYP27B1 expression. In this study, CYP27B1 expression was demonstrated in CCA cells and human CCA specimens. 25(OH)D effectively represses SNU308 cells growth, which was strengthened or attenuated as CYP27B1 overexpression or knockdown. Lipocalcin-2 (LCN2) was also found to be repressed by 25(OH)D. After treatment with 800 ng/mL 25(OH)D, the intracellular 1α,25(OH)2D3 concentration was higher in SNU308 cells with CYP27B1 overexpression than wild type SNU308 cells. In a xenograft animal experiment, 25(OH)D, at a dose of 6 μg/kg or 20 μg/kg, significantly inhibited SNU308 cells’ growth without inducing obvious side effects. Collectively, our results indicated that SNU308 cells were able to convert 25(OH)D to 1α,25(OH)2D3 and 25(OH)D CYP27B1 gene therapy could be deemed as a promising therapeutic direction for CCA.
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- 2016
14. MART-10, a newly synthesized vitamin D analog, represses metastatic potential of head and neck squamous carcinoma cells
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Atsushi Kittaka, Tai C. Chen, Jong-Hwei S. Pang, Yi-Chun Pan, Kun-Chun Chiang, Chun-Nan Yeh, Horng-Heng Juang, Shih-Wei Yang, Chi-Ying Tsai, and Masashi Takano
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0301 basic medicine ,Pathology ,medicine.medical_specialty ,Epithelial-Mesenchymal Transition ,Pharmaceutical Science ,Down-Regulation ,Antineoplastic Agents ,Metastasis ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Downregulation and upregulation ,Cell Line, Tumor ,Drug Discovery ,medicine ,Humans ,metastasis ,Epithelial–mesenchymal transition ,Neoplasm Metastasis ,Vitamin D ,neoplasms ,Cholecalciferol ,Original Research ,vitamin D analog ,Pharmacology ,Drug Design, Development and Therapy ,integumentary system ,business.industry ,EMT ,Cancer ,MART-10 ,medicine.disease ,Head and neck squamous-cell carcinoma ,In vitro ,Squamous carcinoma ,030104 developmental biology ,chemistry ,Matrix Metalloproteinase 9 ,Head and Neck Neoplasms ,030220 oncology & carcinogenesis ,Cancer research ,Carcinoma, Squamous Cell ,head and neck cancer ,business - Abstract
Shih-Wei Yang,1,* Chi-Ying Tsai,2,* Yi-Chun Pan,3 Chun-Nan Yeh,4 Jong-Hwei S Pang,5 Masashi Takano,6 Atsushi Kittaka,6 Horng-Heng Juang,7 Tai C Chen,8 Kun-Chun Chiang4,9 1Department of Otolaryngology– Head and Neck Surgery, Chang Gung Memorial Hospital, Keelung, 2Department of Oral and Maxillofacial Surgery, Chang Gung Memorial Hospital, Taoyuan, 3Department of General Dentistry, Chang Gung Memorial Hospital, Chang Gung University, Keelung, 4General Surgery Department, Chang Gung Memorial Hospital, Keelung, 5Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan, Republic of China; 6Faculty of Pharmaceutical Sciences, Teikyo University, Tokyo, Japan; 7Department of Anatomy, College of Medicine, Chang Gung University, Taoyuan, Taiwan, Republic of China; 8Endocrine Core Laboratory, Boston University School ofMedicine, Boston, MA,USA; 9Zebrafish Center, Chang GungMemorial Hospital, Keelung, Taiwan, Republic of China *These authors contributed equally tothiswork Abstract: Even with multidisciplinary treatment, the prognosis and quality of life of patients diagnosed with head and neck squamous cell carcinoma (HNSCC) are still not satisfactory. Previously, 19-Nor-2α-(3-hydroxypropyl)-1α,25(OH)2D3 (MART-10), the new brand 1α,25(OH)2D3 analog, has been demonstrated to be an effective drug to inhibit HNSCC growth in vitro. Since most cancer patients die of metastasis, in this study, the antimetastatic effect of MART-10 on HNSCC was investigated. Our results reveal that both 1α,25(OH)2D3 and MART-10 effectively repressed the migration and invasion of HNSCC cells, with MART-10 being much more potent than 1α,25(OH)2D3. The antimetastatic effect of 1α,25(OH)2D3 and MART-10 was mediated by attenuation of epithelial–mesenchymal transition (EMT), which was supported by the finding that the expression of EMT-inducing transcriptional factors, Sail and Twist, was inhibited by 1α,25(OH)2D3 and MART-10. The upregulation of E-cadherin and downregulation of N-cadherin in FaDu cells induced by both drugs further confirmed the repression of EMT. In addition, 1α,25(OH)2D3 and MART-10 treatment inhibited intracellular MMP-9 expression and extracellular MMP activity in FaDu cells. Collectively, our results suggest that the less-calcemia 1α,25(OH)2D3 analog, MART-10, is a promising drug for HNSCC treatment. Further clinical studies are warranted. Keywords: EMT, head and neck cancer, vitamin D analog, metastasis, MART-10
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- 2016
15. 1α,25(OH)2D3 Analog, MART-10, Inhibits Neuroendocrine Tumor Cell Growth Through Induction of G0/G1 Cell-cycle Arrest and Apoptosis
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Kun-Chun, Chiang, Chun-Nan, Yeh, Jong-Hwei S, Pang, Jun-Te, Hsu, Ta-Sen, Yeh, Li-Wei, Chen, Sheng-Fong, Kuo, Po-Jen, Hsieh, Yi-Chun, Pan, Masashi, Takano, Tai C, Chen, Tsui-Hsia, Feng, Atsushi, Kittaka, and Horng-Heng, Juang
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Cyclin-Dependent Kinase 4 ,Apoptosis ,Cell Growth Processes ,G1 Phase Cell Cycle Checkpoints ,Rats ,Pancreatic Neoplasms ,Neuroendocrine Tumors ,Calcitriol ,Cell Line, Tumor ,Animals ,Receptors, Calcitriol ,Insulinoma ,Cyclin-Dependent Kinase Inhibitor p27 ,Cholecalciferol - Abstract
Neuroendocrine tumors (NETs) are the second most common digestive malignancy. For advanced NETs, survival is not satisfactory. Vitamin D has emerged as a promising anticancer drug.Cell proliferation assay, western blot, flow cytometry, and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assays were applied.We demonstrated that RIN-m cells, neuroendocrine tumor cells, expressed vitamin D receptor (VDR) and VDR expression increased with increasing exposure to 1α,25-dihydroxyvitamin D3 [1α,25(OH)2D3] or MART-10, a 1α,25(OH)2D3 analog. MART-10 had anti-growth effect on RIN-m cells comparable to those of 1α,25(OH)2D3 The growth inhibition of both drugs was mediated by induction of cell-cycle arrest at G0/G1 phase and apoptosis. Western blot assay further revealed that this G0/G1 arrest was due to the up-regulation of p27 and down-regulation of cyclin dependent kinase 4 (CDK4), with MART-10 also reducing CDK6. Apoptosis induction was further supported by increased cleaved caspase-3 expression after treatment.MART-10 appears to be a promising regimen for NET treatment.
- Published
- 2016
16. Metabolism and Action of 25-Hydroxy-19-nor-Vitamin D₃ in Human Prostate Cells
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Eiji, Munetsuna, Atsushi, Kittaka, Tai C, Chen, and Toshiyuki, Sakaki
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Male ,Molecular Structure ,Humans ,Prostatic Neoplasms ,Receptors, Calcitriol ,Antineoplastic Agents ,Cell Proliferation ,Cholecalciferol - Abstract
Since the discovery of 1α,25(OH)2D3 in the early 1970s, it has been widely accepted that this metabolite is responsible for the biological actions of vitamin D. Likewise, we have assumed that 25(OH)-19-nor-D3-dependent growth inhibition of human prostate PZ-HPV-7 cells was the result of its subsequent conversion to 1α,25(OH)2-19-nor-D3, catalyzed by CYP27B1 within the prostate cells. However, further in vitro studies in a reconstituted system using recombinant CYP27B1 revealed that 25(OH)-19-nor-D3 was hardly converted to 1α,25(OH)2-19-nor-D3 by the enzyme. The kinetic analysis of 1α-hydroxylation of 25(OH)D3 and 25(OH)-19-nor-D3 demonstrated that the k(cat)/K(m) for 25(OH)-19-nor-D3 is less than 0.1% of that for 25(OH)D3. When 25(OH)-19-nor-D3 was added to cultured PZ-HPV-7 cells, eight metabolites were detected, while no 1α,25(OH)2-19-nor-D3 was found. In addition, the time course of VDR translocation into the nucleus induced by 100 nM 25(OH)-19-nor-D3, and the subsequent transactivation of CYP24A1 gene were almost identical to those induced by 1 nM 1α,25(OH)2-19-nor-D3. These results strongly suggest that 25(OH)-19-nor-D3 binds directly to VDR as a ligand to transport VDR into the nucleus to induce CYP24A1 gene transactivation. Furthermore, knockdown of CYP27B1 gene did not affect the antiproliferative activity of 25(OH)-19-nor-D3, whereas VDR knockdown attenuated the effect, suggesting that the antiproliferative activity of 25(OH)-19-nor-D3 is VDR dependent but CYP27B1 independent. Finally, our recent studies using the same cell line demonstrate that 25(OH)D3 can act as a VDR agonist to induce gene transactivation. These findings suggest that vitamin D analogs without 1α-hydroxyl group could be developed as drugs for osteoporosis or cancer treatment.
- Published
- 2016
17. Circulating vascular endothelial growth factor and the risk of cardiovascular events
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Sudha Seshadri, Ramachandran S. Vasan, Tai C. Chen, Alexa S. Beiser, Douglas B. Sawyer, Sarah R. Preis, and Bernhard M. Kaess
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Male ,Vascular Endothelial Growth Factor A ,medicine.medical_specialty ,030204 cardiovascular system & hematology ,Risk Assessment ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Framingham Heart Study ,Predictive Value of Tests ,Risk Factors ,Internal medicine ,medicine ,Humans ,Prospective Studies ,Prospective cohort study ,Aged ,Proportional Hazards Models ,business.industry ,Proportional hazards model ,Incidence (epidemiology) ,Incidence ,Middle Aged ,Prognosis ,Up-Regulation ,Vascular endothelial growth factor ,Endocrinology ,Quartile ,chemistry ,Massachusetts ,Nonlinear Dynamics ,Cardiovascular Diseases ,Predictive value of tests ,Multivariate Analysis ,Cardiology ,Female ,Cardiology and Cardiovascular Medicine ,business ,Risk assessment ,030217 neurology & neurosurgery ,Biomarkers - Abstract
To investigate the relation of circulating concentrations of vascular endothelial growth factor (VEGF) for the risk of developing cardiovascular disease (CVD) in a large community-based sample.We prospectively assessed the relation of circulating VEGF concentrations with the incidence of CVD among 3041 Framingham Heart Study participants (mean age 63.4±11.1 years, 59% women). Multivariable Cox proportional hazards models were estimated adjusting for standard risk factors to VEGF quartiles to incident CVD. Restricted cubic splines were used to examine the linearity of the association.After a mean follow-up of 8.8 (±2.8) years, 527 individuals experienced a first CVD event. Compared with participants in the first VEGF quartile, individuals in the second VEGF quartile had a 34% increased risk for future CVD (HR 1.34, 95% CI 1.03 to 1.74; p value=0.03) and individuals in third quartile had a 59% higher risk (HR 1.59; 95% CI 1.23 to 2.05, p value=0.0003). Individuals in the highest VEGF quartile had a similar cardiovascular risk as compared with those in the lowest VEGF quartile (HR 1.18, 95% CI 0.91 to 1.53, p value=0.21). Evaluation of restricted cubic splines confirmed the nonlinear, inverted U-shaped relation of serum VEGF and CVD events (p0.0001 for model fit, p=0.006 for non-linearity).Circulating VEGF concentrations exhibit a complex non-linear (inverted U-shaped) relation with the risk of developing CVD events, with the lowest risk experienced at the lower and upper end of the distribution. The underlying pathophysiological mechanisms remain to be elucidated.
- Published
- 2015
18. P3‐081: Associations between BDNF serum levels and Alzheimer's disease‐related measures: The framingham study
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Alexa S. Beiser, Claudia L. Satizabal, Nicole L. Spartano, Sarah R. Preis, Sudha Seshadri, Tai C. Chen, Galit Weinstein, and Vasan S. Ramachandran
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medicine.medical_specialty ,Epidemiology ,business.industry ,Health Policy ,Disease ,Psychiatry and Mental health ,Cellular and Molecular Neuroscience ,Framingham Heart Study ,Developmental Neuroscience ,Internal medicine ,Medicine ,Neurology (clinical) ,Geriatrics and Gerontology ,business - Published
- 2015
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19. Assessing Vitamin D 3 Stability in Dietary Supplements
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Shi Su and Tai C. Chen
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Vitamin ,business.industry ,Physiology ,Disease ,medicine.disease ,Biochemistry ,Obesity ,Bone health ,chemistry.chemical_compound ,chemistry ,Diabetes mellitus ,Genetics ,Vitamin D and neurology ,medicine ,business ,Molecular Biology ,Biotechnology - Abstract
It is well recognized that vitamin D plays an important role not only in bone health but also in the prevention of various chronic diseases, including obesity, diabetes, cardiovascular disease and ...
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- 2015
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20. Hepatocellular carcinoma cells express 25(OH)D-1α-hydroxylase and are able to convert 25(OH)D to 1α,25(OH)₂D, leading to the 25(OH)D-induced growth inhibition
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Kun-Chun, Chiang, Cho-Li, Yen, Chun-Nan, Yeh, Jun-Te, Hsu, Li-Wei, Chen, Sheng-Fong, Kuo, Shang-Yu, Wang, Chi-Chin, Sun, Atsushi, Kittaka, Tai C, Chen, Ta-Sen, Yeh, Shu-Yuan, Hsu, and Horng-Heng, Juang
- Subjects
25-Hydroxyvitamin D3 1-alpha-Hydroxylase ,Carcinoma, Hepatocellular ,Liver Neoplasms ,Humans ,Hep G2 Cells ,Vitamin D ,Cell Proliferation - Abstract
Hepatocellular carcinoma (HCC) is the most diagnosed liver cancer without effective treatments available for advanced HCC. Vitamin D is getting popular due to its anti-cancer characteristics. However, the clinical application of 1α,25(OH)2D, the active form of vitamin, is hampered by its hypercalcemia side effect. 1α,25(OH)2D is converted from 25(OH)D, the index of serum vitamin D status, by CYP27B1, which is originally found in kidneys but recently detected in non-renal tissues. 25(OH)D has been shown to repress some cancers expressing CYP27B1 due to the local conversion of 25(OH)D to 1α,25(OH)2D, which works in a intra-, auto-, or paracrine manner and thus minimizes the risk of hypercalcemia. In this study, we found CYP27B1 expression in human hepatocyte, HCC, and HepG2 cells. As we treated HepG2 cells with 25(OH)D, the 1α,25(OH)2D target gene CYP24A1 expression was increased and was further upregulated as CYP27B1 transfection or downregulated as CYP27B1 knockdown. Other 1α,25(OH)2D target genes in HepG2 cells, p21 and p27 were also stimulated by 25(OH)D after CYP27B1 transfection. Further, 25(OH)D could inhibit HepG2 cells growth, which was potentiated by CYP27B1 transfection. Collectively, we showed for the first time that HCC expressed CYP27B1 and was able to covert 25(OH)D to 1α,25(OH)2D in vitro, thus responsive to 25(OH)D treatment. Our data justifies the application of 25(OH)D and CYP27B1 gene transfection therapy in further HCC treatment studies.
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- 2015
21. The Vitamin D Analog, MART-10, Attenuates Triple Negative Breast Cancer Cells Metastatic Potential
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Chun-Nan Yeh, Horng-Heng Juang, Atsushi Kittaka, Sheng-Fong Kuo, Chi-Chin Sun, Ta-Sen Yeh, Kun-Chun Chiang, Jong-Hwei S. Pang, Shin-Cheh Chen, Li-Wei Chen, Tai C. Chen, Jun-Te Hsu, and Masashi Takano
- Subjects
0301 basic medicine ,Oncology ,Triple Negative Breast Neoplasms ,vitamin D ,lcsh:Chemistry ,chemistry.chemical_compound ,0302 clinical medicine ,Cell Movement ,Medicine ,Neoplasm Metastasis ,lcsh:QH301-705.5 ,Spectroscopy ,Triple-negative breast cancer ,Cholecalciferol ,integumentary system ,EMT ,MART-10 ,General Medicine ,Cadherins ,Computer Science Applications ,Gene Expression Regulation, Neoplastic ,030220 oncology & carcinogenesis ,Growth inhibition ,TNBC ,medicine.medical_specialty ,Article ,Catalysis ,Inorganic Chemistry ,03 medical and health sciences ,Breast cancer ,Downregulation and upregulation ,Cell Line, Tumor ,Internal medicine ,Humans ,Neoplasm Invasiveness ,Epithelial–mesenchymal transition ,Physical and Theoretical Chemistry ,Molecular Biology ,triple negative breast cancer ,business.industry ,Cadherin ,Organic Chemistry ,Cancer ,medicine.disease ,030104 developmental biology ,lcsh:Biology (General) ,lcsh:QD1-999 ,chemistry ,business - Abstract
Regarding breast cancer treatment, triple negative breast cancer (TNBC) is a difficult issue. Most TNBC patients die of cancer metastasis. Thus, to develop a new regimen to attenuate TNBC metastatic potential is urgently needed. MART-10 (19-nor-2α-(3-hydroxypropyl)-1α,25(OH)₂D₃), the newly-synthesized 1α,25(OH)₂D₃ analog, has been shown to be much more potent in cancer growth inhibition than 1α,25(OH)₂D₃ and be active in vivo without inducing obvious side effect. In this study, we demonstrated that both 1α,25(OH)₂D₃ and MART-10 could effectively repress TNBC cells migration and invasion with MART-10 more effective. MART-10 and 1α,25(OH)₂D₃ induced cadherin switching (upregulation of E-cadherin and downregulation of N-cadherin) and downregulated P-cadherin expression in MDA-MB-231 cells. The EMT(epithelial mesenchymal transition) process in MDA-MB-231 cells was repressed by MART-10 through inhibiting Zeb1, Zeb2, Slug, and Twist expression. LCN2, one kind of breast cancer metastasis stimulator, was also found for the first time to be repressed by 1α,25(OH)₂D₃ and MART-10 in breast cancer cells. Matrix metalloproteinase-9 (MMP-9) activity was also downregulated by MART-10. Furthermore, F-actin synthesis in MDA-MB-231 cells was attenuated as exposure to 1α,25(OH)₂D₃ and MART-10. Based on our result, we conclude that MART-10 could effectively inhibit TNBC cells metastatic potential and deserves further investigation as a new regimen to treat TNBC.
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- 2016
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22. Summer and Winter Seasonal Changes in Vitamin D Status of Captive Rhinoceros Iguanas (Cyclura cornuta)
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Gary W. Ferguson, William H. Gehrmann, Michael F. Holick, Kelly A. Bradley, Ruston Hartdegen, Tai C. Chen, Tim Storms, and Bradley Lawrence
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Sunlight ,Vitamin ,biology ,Ecology ,Rhinoceros ,Ultraviolet b ,biology.organism_classification ,chemistry.chemical_compound ,Geography ,Animal science ,chemistry ,Vitamin D and neurology ,Health risk ,skin and connective tissue diseases ,Rhinoceros iguana ,Cyclura - Abstract
Four long-term captive adult rhinoceros iguanas (Cyclura cornuta) on display at the Dallas Zoo (Dallas, TX) were maintained for several years in an outdoor enclosure in the summer and in a smaller indoor enclosure in the winter. While fully exposed to sunlight and given the opportunity to supplement their diet with live vegetation each summer, they were deprived of the benefits of full sun exposure, including ultraviolet B (UVB) exposure, and they received no dietary vitamin D for several months each winter. Maintained with this protocol, the animals seemed healthy and they reproduced. However, increasing awareness of the important role of UVB in vitamin D–mediated calcium metabolism and the potential health risk of UVB and vitamin D deprivation stimulated us to focus more on seasonal changes in vitamin D status and possible subtle changes in health status throughout winter. From September 2008 to October 2010, an 85% decline in the serum 25-hydroxyvitamin D3 (calcidiol) concentrations was measur...
- Published
- 2015
- Full Text
- View/download PDF
23. 25(OH)D Is Effective to Repress Human Cholangiocarcinoma Cell Growth through the Conversion of 25(OH)D to 1α,25(OH)2D3.
- Author
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Kun-Chun Chiang, Chun-Nan Yeh, Cheng-Cheng Huang, Ta-Sen Yeh, Jong-Hwei S. Pang, Jun-Te Hsu, Li-Wei Chen, Sheng-Fong Kuo, Atsushi Kittaka, Tai C. Chen, and Horng-Heng Juang
- Subjects
CHOLANGIOCARCINOMA ,VITAMIN D ,ANTINEOPLASTIC agents ,HYPERCALCEMIA ,HYDROXYLATION - Abstract
Cholangiocarcinoma (CCA) is a devastating disease without effective treatments. 1α,25(OH)
2 D3 , the active form of Vitamin D, has emerged as a new anti-cancer regimen. However, the side effect of hypercalcemia impedes its systemic administration. 25(OH)D is biologically inert and needs hydroxylation by CYP27B1 to form 1α,25(OH)2 D3 , which is originally believed to only take place in kidneys. Recently, the extra-renal expression of CYP27B1 has been identified and in vitro conversion of 25(OH)D to 1α,25(OH)2 D3 has been found in some cancer cells with CYP27B1 expression. In this study, CYP27B1 expression was demonstrated in CCA cells and human CCA specimens. 25(OH)D effectively represses SNU308 cells growth, which was strengthened or attenuated as CYP27B1 overexpression or knockdown. Lipocalcin-2 (LCN2) was also found to be repressed by 25(OH)D. After treatment with 800 ng/mL 25(OH)D, the intracellular 1α,25(OH)2 D3 concentration was higher in SNU308 cells with CYP27B1 overexpression than wild type SNU308 cells. In a xenograft animal experiment, 25(OH)D, at a dose of 6 µg/kg or 20 µg/kg, significantly inhibited SNU308 cells' growth without inducing obvious side effects. Collectively, our results indicated that SNU308 cells were able to convert 25(OH)D to 1α,25(OH)2 D3 and 25(OH)D CYP27B1 gene therapy could be deemed as a promising therapeutic direction for CCA. [ABSTRACT FROM AUTHOR]- Published
- 2016
- Full Text
- View/download PDF
24. 25(OH)D Is Effective to Repress Human Cholangiocarcinoma Cell Growth through the Conversion of 25(OH)D to 1α,25(OH)2D3.
- Author
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Kun-Chun Chiang, Chun-Nan Yeh, Cheng-Cheng Huang, Ta-Sen Yeh, Jong-Hwei S. Pang, Jun-Te Hsu, Li-Wei Chen, Sheng-Fong Kuo, Atsushi Kittaka, Tai C. Chen, and Horng-Heng Juang
- Subjects
- *
CHOLANGIOCARCINOMA , *VITAMIN D , *ANTINEOPLASTIC agents , *HYPERCALCEMIA , *HYDROXYLATION - Abstract
Cholangiocarcinoma (CCA) is a devastating disease without effective treatments. 1α,25(OH)2D3, the active form of Vitamin D, has emerged as a new anti-cancer regimen. However, the side effect of hypercalcemia impedes its systemic administration. 25(OH)D is biologically inert and needs hydroxylation by CYP27B1 to form 1α,25(OH)2D3, which is originally believed to only take place in kidneys. Recently, the extra-renal expression of CYP27B1 has been identified and in vitro conversion of 25(OH)D to 1α,25(OH)2D3 has been found in some cancer cells with CYP27B1 expression. In this study, CYP27B1 expression was demonstrated in CCA cells and human CCA specimens. 25(OH)D effectively represses SNU308 cells growth, which was strengthened or attenuated as CYP27B1 overexpression or knockdown. Lipocalcin-2 (LCN2) was also found to be repressed by 25(OH)D. After treatment with 800 ng/mL 25(OH)D, the intracellular 1α,25(OH)2D3 concentration was higher in SNU308 cells with CYP27B1 overexpression than wild type SNU308 cells. In a xenograft animal experiment, 25(OH)D, at a dose of 6 µg/kg or 20 µg/kg, significantly inhibited SNU308 cells' growth without inducing obvious side effects. Collectively, our results indicated that SNU308 cells were able to convert 25(OH)D to 1α,25(OH)2D3 and 25(OH)D CYP27B1 gene therapy could be deemed as a promising therapeutic direction for CCA. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
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