1
|
Marshall DC, Shim A, Chen CC, Lin H, Yu F, Argiriadi P, Choi IJ, Chhabra AM, Simone CB. A Dosimetric Assessment of Sexual Organ Sparing Proton Radiotherapy in Female Pelvic Cancer Patients. Int J Radiat Oncol Biol Phys 2023; 117:e695. [PMID: 37786040 DOI: 10.1016/j.ijrobp.2023.06.2174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Optimizing treatment techniques for female patients undergoing curative treatment for pelvic cancers requires incorporating the goals of maximizing cure while maintaining quality of life. Optimizing treatment to maintain sexual quality of life has received little attention in female patients despite the presence of and toxicity risks to functional anatomic organs and their associated neurovasculature, including the bulboclitoris, vagina, and ovaries. Recent dosimetric data without employing sexual organ sparing suggest that mean VMAT dose to the bulboclitoris in low rectal cancer is around 3300 cGy, and in anal cancer, mean dose is around 2000 cGy to the external genitalia and 4500-5000 cGy to the bulboclitoris, all of which would be expected to result in clinically significant toxicity. Therefore, investigation of the avoidance of these important organs is needed and we hypothesize that proton techniques may achieve greater sparing than photon techniques. MATERIALS/METHODS In this study, we dosimetrically compare proton- vs. photon-based techniques in sparing functional sexual organs. The cohort consisted of four consecutive female pelvic cancer cases that had received 5000 cGy or greater. All cases were re-planned with VMAT and protons while optimizing dose to functional sexual organs and maintaining target coverage. Sexual organ structures assessed include the genitalia, vagina, ovaries, bulboclitoris and internal pudendal arteries. Given the small number of patients included in this demonstration study, statistical tests were not performed. RESULTS MRI was required to appropriately delineate soft tissue. In all cases, dosimetric sparing of sexual organs was improved with proton therapy without compromising target coverage. Mean doses were marginally decreased for structures within the PTV, while structures such as the bulboclitoris were spared substantially. Mean dose to the external genitalia was low with sparing using both VMAT (Median [IQR] (cGy): 852 [811, 1090]) and Proton techniques (Median [IQR] (cGy): 39.4 [11.9, 78.5]). Similarly, mean dose with sparing to the external genitalia was lower than would be expected without sparing, using both VMAT and Proton techniques (Median (IQR) Dmean (cGy) VMAT 3100 [2890, 3580] vs. Proton 1530 [1100, 2090]), with protons demonstrating greater sparing. In one case of a sacral chordoma, ovaries were substantially spared to below ablative thresholds (Dmean (cGy) VMAT 3598.8 and 3548.0 vs Proton 34.1 and 103.3). CONCLUSION Magnetic resonance imaging at simulation combined with proton radiotherapy for female sexual organ sparing may provide a technically feasible route to more equitable sexual outcomes for female patients. These results will guide future studies to optimize proton treatment techniques for female sexual organ sparing for future trials.
Collapse
|
2
|
Chen CC. [Minimally invasive surgery in the concept of enhanced recovery after surgery]. ZHONGHUA WEI CHANG WAI KE ZA ZHI = CHINESE JOURNAL OF GASTROINTESTINAL SURGERY 2022; 25:632-635. [PMID: 35844128 DOI: 10.3760/cma.j.cn441530-20220323-00113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Enhanced recovery after surgery (ERAS) and minimally invasive surgery are two important development directions of modern surgery in the 21st century. They provide new clinical treatment methods and theoretical basis for the rapid recovery of surgical patients and more rational utilization of medical resources. They are two hot topics in clinical research and academic exchange of surgery-related subjects, and promote the rapid development and clinical application of surgery. ERAS covers a range of preoperative, intraoperative, and postoperative optimization measures, of which minimally invasive surgery is an important part of intraoperative optimization. The quality of surgery, especially minimally invasive surgery, plays a key role in postoperative recovery, which is the most important one of all ERAS measures. With good surgical quality and no postoperative complications, patients will recover quickly. Therefore, minimally invasive surgery plays a central role in the ERAS concept. The combination of ERAS with minimally invasive surgery is not only safe and feasible, but is also better than these two clinical therapies alone for postoperative recovery, and improves short-term and long-term outcome and accelerates the recovery of patients. For surgical diseases treated with minimally invasive surgery as far as possible, using the ERAS management for patients will result in reduced traumatic stress, better surgical tolerance, less postoperative pain, smaller incision, earlier ambulation, better organ function, and less morbidity of complications. In short, ERAS and minimally invasive surgery complement and promote each other. As two outstanding achievements of modern medicine, they are clinical treatments that provide sufficient theoretical basis for rapid recovery of patients and open a new chapter for the development of modern surgery.
Collapse
|
3
|
Chung LYR, Lin YT, Liu C, Tai YC, Lin HY, Lin CH, Chen CC. Neuroinflammation Upregulated Neuronal Toll-Like Receptors 2 and 4 to Drive Synucleinopathy in Neurodegeneration. Front Pharmacol 2022; 13:845930. [PMID: 35401198 PMCID: PMC8987529 DOI: 10.3389/fphar.2022.845930] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 02/01/2022] [Indexed: 11/16/2022] Open
Abstract
Background: Parkinson’s disease (PD) is characterized by intraneuronal α-synuclein aggregation called Lewy bodies and progressive dopaminergic neurodegeneration. Toll-like receptor (TLR) signaling is a major pathway mediating inflammation. The molecular link on how neuroinflammation upregulates neuronal TLRs and induces accumulation of α-synuclein aggregates to drive synucleinopathy remains to be determined. Objective: Despite conditioned medium from microglia and TLR agonists were utilized to study their effects on neuronal cells, a Transwell coculture system, comprising lipopolysaccharide-activated microglia on top and retinoic acid-differentiated SH-SY5Y cells at the bottom more mimicking in vivo neuroinflammation, was employed to elucidate the mechanism of activated microglia on neuronal cells. Methods: Genetic variants of TLRs in PD patients were genotyped and the multiplex cytokines, sRAGE, and HMGB1were assessed. A coculture system was employed to measure α-synuclein aggregates and neurite shortening by confocal microscope. The expression of TLR2/4 and autophagy flux was detected by western blot and immunofluorescence. Results: PD patients showed higher plasma levels of proinflammatory cytokines and genetic TLR4 variant, c.896 A > G (p. D299G). Elevated proinflammatory cytokines in coculture medium was also seen. Phosphorylation and aggregation of α-synuclein, shortening of neurite, upregulation of TLR2/4 expression, activation of downstream p38 and JNK, and dampening of autophagic flux were seen in SH-SY5Y cells cocultured with activated microglia. Those were prevented by inhibiting TLR2/4 and p38/JNK signaling. Conclusion: Activated microglia-derived neuroinflammation induced neuronal TLR2/4-p38/JNK activation to perturb autophagy, causing accumulation of α-synuclein aggregates and neurite shortening. Targeting neuronal TLR2/4 pathway might be a mechanistic-based therapy for neurodegenerative disease, such as PD.
Collapse
|
4
|
Hu HY, Cheng FS, Yen YF, Lin SY, Weng SH, Chou YC, Chu DC, Chen CC. Mask reuse during the COVID-19 pandemic: a national survey in Taiwan. Eur J Public Health 2021. [DOI: 10.1093/eurpub/ckab165.049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
The use of masks is an effective measure to prevent severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) infection; however, mask reuse is not recommended. Studies examining the factors associated with mask reuse during the coronavirus disease (COVID-19) pandemic are limited. This nationwide survey aimed to determine the prevalence and factors associated with mask reuse among Taiwanese citizens during the pandemic.
Methods
From May 18 through May 31, 2020, a computer-assisted telephone interview system was used to randomly select Taiwanese citizens who were interviewed for COVID-19 preventive behaviors and knowledge on the usage of masks. Multivariate logistic regression was used to identify factors associated with mask reuse during the COVID-19 pandemic. Moreover, generalized estimating equations (GEE) were used to analyze the rate of mask reuse among participants before and during the pandemic.
Results
For a total of 1,075 participants, the overall mean age was 57.4 years, and 82.2% of participants reported mask reuse during the COVID-19 pandemic. After controlling for other covariates, participants who had a greater knowledge on mask usage or had a high supply of masks were less likely to reuse masks during the pandemic. GEE analysis showed that compared with the participants' mask wearing behaviors before the COVID-19 pandemic, they were more likely to reuse masks during the pandemic.
Conclusions
The rate of mask reuse among the general population during the pandemic was significantly higher than that before the pandemic. Individuals were less likely to reuse masks if they had adequate knowledge on mask usage or had a high supply of masks. Since mask reuse is associated with a higher risk of COVID-19 due to the possibility of wearing SAS-CoV-2-contaminated masks, it is imperative to educate people on the correct usage of masks. Further, the government should provide sufficient masks to the general population to decrease the reuse of masks.
Key messages
Mask reuse increased during the COVID-19 pandemic due to the shortage in supply. It is imperative to educate people about the correct usage of masks.
Collapse
|
5
|
Lin CH, Lin HY, Fang JM, Chen CC. A dual inhibitor targeting HMG-CoA reductase and histone deacetylase mitigates neurite degeneration in LRRK2-G2019S parkinsonism. Aging (Albany NY) 2020; 12:25581-25598. [PMID: 33231564 PMCID: PMC7803522 DOI: 10.18632/aging.104165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 08/27/2020] [Indexed: 06/11/2023]
Abstract
Parkinson's disease (PD) is among the most common neurodegenerative disorders, and its etiology involves both genetic and environmental factors. The leucine-rich repeat kinase (LRRK2) G2019S mutation is the most common genetic cause of familial and sporadic PD. Current treatment is limited to dopaminergic supplementation, as no disease-modifying therapy is available yet. Recent evidence reveals that HMG-CoA reductase (HMGR) inhibitors (statins) exert neuroprotection through anti-neuroinflammatory effects, and histone deacetylase (HDAC) inhibitors mitigate neurodegeneration by promoting the transcription of neuronal survival factors. We designed and synthesized a dual inhibitor, statin hydroxamate JMF3086, that simultaneously inhibits HMGR and HDAC, and examined its neuroprotective effects on LRRK2-G2019S parkinsonism. JMF3086 restored dopaminergic neuron loss in aged LRRK2-G2019S flies and rescued neurite degeneration in primary hippocampal and dopaminergic neurons isolated from transgenic LRRK2-G2019S mice. The molecular mechanisms included downregulation of ERK1/2 phosphorylation, increased anti-apoptotic Akt phosphorylation, and inhibition of GSK3β activity to maintain cytoskeletal stability in stably transfected LRRK2-G2019S SH-SY5Y human dopaminergic cells. JMF3086 also promoted a-tubulin acetylation and kinesin-1 expression, facilitating antegrade mitochondrial transport in axons. Our findings demonstrate that JMF3086 exerted beneficial effects on restoring LRRK2-G2019S neurite degeneration by maintaining microtubule stability. This dual-target compound may be a promising mechanism-based therapy for PD.
Collapse
|
6
|
Huang SH, Shih JY, Chen CC. Abstract B26: Role of AKT3 in EGFR-TKI resistance of non-small cell lung cancer. Mol Cancer Res 2020. [DOI: 10.1158/1557-3125.pi3k-mtor18-b26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Lung cancer is the leading cause of cancer deaths worldwide, and EGFR-TKI is the first-line treatment for non-small cell lung cancer (NSCLC) harboring EGFR activation mutation. However, most patients develop acquired resistance within 9–14 months. Exploring the mechanisms of drug resistance is critical to improve treatment efficacy. Two resistant cells, HCC827/IR (IRESSA resistance) and H1975/AR (AZD9291 resistance), exhibiting EMT phenotypes were generated to investigate the molecular and cellular characteristics of the EGFR-TKI acquired resistance. HCC827/IR (without T790M) and H1975/AR (without C797S) showed “off-target resistance”. Upregulation of AXL and FGFR1 in HCC827/IR but not H1975/AR cells was found. AKT activation (p-AKT) in parental cells was more sensitive to EGFR-TKI than that in resistant cells. RNA-seq revealed the upregulation of AKT3 in both resistant cells. High expression of AKT3 was predicted to correlate with the poor survival of lung adenocarcinoma patients. Knockdown of AKT3 in HCC827/IR cells inhibited cell migration and increased the protein expression of E-cadherin, as well as inhibited S phase population to reduce cell proliferation. Knockdown of AKT3 in H1975/AR cells enhanced AZD9291-induced inhibition on AKT activation (p-AKT). Immunoprecipitation of AKT3 in both resistant cells demonstrated its involvement in AKT activation, and AKT3 activation (p-AKT3) was insensitive to gefitinib and AZD9291 inhibition in resistant cells. Protein but not mRNA of AKT3 was upregulated in gefitinib-treated HCC827/IR and AZD9291-treated H1975/AR cells. AKT3 might serve as a predictive biomarker for EGFR-TKIs therapy. Its upregulation might be one of the mechanisms for EGFR-TKIs acquired resistance.
Citation Format: Shih-Hsiang Huang, Jin-Yuan Shih, Ching-Chow Chen. Role of AKT3 in EGFR-TKI resistance of non-small cell lung cancer [abstract]. In: Proceedings of the AACR Special Conference on Targeting PI3K/mTOR Signaling; 2018 Nov 30-Dec 8; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(10_Suppl):Abstract nr B26.
Collapse
|
7
|
Guo JD, Hlavacek P, Poretta T, Wygant G, Lane D, Gorritz M, Wang X, Chen CC, Wade RL, Pan X, Rajpura J, Stwalley B, Rosenblatt L. Inpatient and outpatient treatment patterns of cancer-associated thrombosis in the United States. J Thromb Thrombolysis 2020; 50:386-394. [PMID: 31955338 PMCID: PMC7366581 DOI: 10.1007/s11239-019-02032-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Low molecular weight heparins (LMWHs) and direct oral anticoagulants (DOACs) are among the recommended treatment options for cancer-associated thrombosis (CAT) in the 2019 National Comprehensive Care Network guidelines. Little is known about the current utilization of DOACs in CAT patients, particularly on the inpatient to outpatient therapy transition. This study assessed real-world treatment patterns of CAT in hospital/ED in adult cancer patients (≥ 18 years) diagnosed with CAT during a hospital visit in IQVIA's Hospital Charge Data Master database between July 1, 2015 and April 30, 2018, and followed their outpatient medical and pharmacy claims to evaluate the initial inpatient/ED and outpatient anticoagulants received within 3 months post-discharge. Results showed that LMWH and unfractionated heparin (UFH) were the most common initial inpatient/ED CAT treatments (35.2% and 27.4%, respectively), followed by DOACs (9.6%); 20.8% of patients received no anticoagulants. Most DOAC patients remained on DOACs from inpatient/ED to outpatient settings (71.4%), while 24.1%, 43.5%, and 0.1% of patients treated with LMWH, warfarin, or UFH respectively, remained on the same therapy after discharge. In addition, DOACs were the most common initial post-discharge outpatient therapy. Outpatient treatment persistence and adherence appeared higher in patients using DOACs or warfarin versus LMWH or UFH. This study shows that DOACs are used as an inpatient/ED treatment option for CAT, and are associated with less post-discharge treatment switching and higher persistence and adherence. Further research generating real-world evidence on the role of DOACs to help inform the complex CAT clinical treatment decisions is warranted.
Collapse
|
8
|
Miaw SC, Lin YT, Hsu YH, Liu C, Shun CT, Chen CC. Serine phosphorylation of CREB-binding protein (CBP) is critical to intestinal homeostasis but not CD4 T cell differentiation. THE JOURNAL OF IMMUNOLOGY 2020. [DOI: 10.4049/jimmunol.204.supp.230.19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
CREB-binding protein (CBP) is a transcriptional coactivator involved in the regulation of DNA accessibility to transcription factors. Phosphorylation of human CBP by IKKα at Ser1382/1386 plays a critical role in the regulation of cell fate by suppressing p53-mediated gene expression. Therefore, we evaluated whether impaired serine phosphorylation of CBP is involved in the pathogenesis of disease. We generated mutated serine 1383/1387 to alanine knock-in mice (AA mice) to study whether they exhibit any phenotype alteration. AA mice showed an IBD-like phenotype with softer, looser and hemoccult stools and shorter colon length compared to the wild type mice. Increased p53 accompanied with apoptosis in colonic tissues of AA mice was demonstrated by IHC and TUNEL staining. In addition, male AA mice were more vulnerable to DSS-induced colitis with severe crypt loss and epithelial disruption. Elevated immune cells in mesenteric lymph nodes are more prominent in AA mice with infiltration of neutrophil and macrophage. However, the differentiation of CD4+ T cells was not affected with Cbp mutation (AA) ex vivo. Taken together, deficiency of NF-kB signaling in AA mice did not affect immune cells but modulated apoptosis of IECs. Our findings suggested that serine phosphorylation of CBP by IKKα might be a critical regulator to maintain intestinal homeostasis.
Collapse
|
9
|
Huang SH, Shih JY, Chen CC. Abstract A49: Acquired resistance of non-small cell lung cancer to EGFR-TKI: Role of AKT3. Cancer Immunol Res 2020. [DOI: 10.1158/2326-6074.tumimm19-a49] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The discovery of EGFR-TKIs has had a dramatic impact on the treatment of NSCLC with EGFR activation mutation. Although they improve the overall survival, the main obstacle is the emergence of acquired resistance. Two resistant cells, HCC827/IR (IRESSA resistance) and H1975/AR (AZD9291 resistance), generated and showing “off-target resistance,” were employed to investigate the molecular and cellular characteristics of the acquired resistance to EGFR-TKIs. AKT activation (p-AKT) in both parental cells was more sensitive to EGFR-TKIs than that in resistant cells. We found that mRNA and protein of AKT3, but not AKT1 and AKT2, were upregulated in both HCC827/IR and H1975/AR cells. Immunoprecipitation of AKT3 demonstrated its contribution to AKT activation. Knockdown of AKT3 in both resistant cells decreased basal AKT activation (p-AKT). However, the insensitive inhibition of gefitinib on AKT activation (p-AKT) in HCC827/IR cells and AZD9291in H1975/AR cells remained even if AKT3 was knocked down. AKT3 protein, but not AKT1 and AKT2, was found to be overexpressed in resistant cells treated with gefitinib or AZD9291 as well as AKT3 KD, indicating the crucial role of AKT3 in acquired resistance to EGFR-TKIs. Combination of AKT inhibitors with AZD9291 showed synergistic inhibition on cell viability of H1975/AR cells. Therefore, AKT3 upregulation might be one of the mechanisms for acquired resistance to EGFR-TKIs, and it might serve as a predictive biomarker for EGFR-TKIs therapy.
Citation Format: Shih-Hsiang Huang, Jin-Yuan Shih, Ching-Chow Chen. Acquired resistance of non-small cell lung cancer to EGFR-TKI: Role of AKT3 [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr A49.
Collapse
|
10
|
Lin YC, Wu MH, Wei TT, Lin YC, Huang WC, Huang LY, Lin YT, Chen CC. Correction: Metformin sensitizes anticancer effect of dasatinib in head and neck squamous cell carcinoma cells through AMPK-dependent ER stress. Oncotarget 2019; 10:5724-5725. [PMID: 31620247 PMCID: PMC6779279 DOI: 10.18632/oncotarget.27228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
|
11
|
Wei TT, Lin YT, Tang SP, Luo CK, Tsai CT, Shun CT, Chen CC. Metabolic targeting of HIF-1α potentiates the therapeutic efficacy of oxaliplatin in colorectal cancer. Oncogene 2019; 39:414-427. [PMID: 31477841 DOI: 10.1038/s41388-019-0999-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 07/25/2019] [Accepted: 08/15/2019] [Indexed: 12/14/2022]
Abstract
Drug resistance is a major problem limiting the efficacy of chemotherapy in cancer treatment, and the hypoxia-induced stabilization of HIF-1α plays a role in this process. HIF-1α overexpression has been observed in a variety of human cancers, including colorectal cancer (CRC). Therefore, targeting HIF-1α is a promising strategy for overcoming chemoresistance to enhance the efficacy of chemotherapies in CRC. Here, we show that DNMT inhibitors can induce HIF-1α degradation to overcome oxaliplatin resistance and enhance anti-CRC therapy. We found that a low-toxicity DNMT inhibitor, zebularine, could downregulate HIF-1α expression and overcome hypoxia-induced oxaliplatin resistance in HCT116 cells and showed efficacy in HCT116 xenograft models and AOM/DSS-induced CRC mouse models. Zebularine could induce the degradation of HIF-1α protein through hydroxylation. LC-MS analysis showed a decrease in succinate in various CRC cells under hypoxia and in colon tissues of AOM/DSS-induced CRC mice. The decrease was reversed by zebularine. Tumor angiogenesis was also reduced by zebularine. Furthermore, zebularine potentiated the anticancer effect of oxaliplatin in AOM/DSS-induced CRC models. This finding provides a new strategy in which an increase in HIF-1α hydroxylation could overcome oxaliplatin resistance to enhance anti-CRC therapy.
Collapse
|
12
|
Huang SH, Shih JY, Chen CC. Abstract 3025: Investigation of AKT3 in the resistance of non-small cell lung cancer to EGFR-TKI. Cancer Res 2019. [DOI: 10.1158/1538-7445.am2019-3025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Lung cancer is the leading cause of cancer deaths worldwide, and EGFR-TKI is the first-line treatment for non-small cell lung cancer (NSCLC) harboring EGFR activation mutation. However, most patients develop acquired resistance around 12 months. Two resistant cells, HCC827/IR (IRESSA resistance) and H1975/AR (AZD9291 resistance) exhibiting EMT phenotypes were generated to investigate the molecular and cellular characteristics of the EGFR-TKI acquired resistance.
The expression and activation of EGFR were reduced in both resistant cells. Upregulation of AXL and FGFR1 were found in HCC827/IR but not H1975/AR cells. HCC827/IR (without T790M) and H1975/AR (without C797S) showed “off target resistance”. Activation of AKT (p-AKT) in both parental cells was more sensitive to EGFR-TKI than that in resistant cells. RNA-seq revealed that AKT3 was upregulated in both resistant cells. High expression of AKT3 was predicted to correlate with the poor survival of lung adenocarcinoma patients. Knockdown of AKT3 in HCC827/IR cells inhibited cell migration and increased the protein expression of E-cadherin, as well as inhibited S phase population to reduce cell proliferation. Knockdown of AKT3 in H1975/AR cells enhanced AZD9291-induced inhibition on AKT activation (p-AKT). Immunoprecipitation of AKT3 in both resistant cells demonstrated its involvement in AKT activation, and AKT3 activation (p-AKT3) was not sensitive to inhibition by gefitinib and AZD9291 in resistant cells. We also found that protein but not mRNA of AKT3 was upregulated in gefitinib-treated HCC827/IR and AZD9291-treated H1975/AR cells. Therefore, AKT3 might serve as a predictive biomarker for EGFR-TKIs therapy, and its upregulation might be one of the mechanisms for EGFR-TKIs acquired resistance. In addition, combination of AZD9291 with AKT inhibitors elicited synergistic inhibition on cell viability of H1975/AR cells.
This work was supported by the National Health Research Institutes (NHRI)- NHRI-EX107-10707BI.
Citation Format: Shih-Hsiang Huang, Jin-Yuan Shih, Ching-Chow Chen. Investigation of AKT3 in the resistance of non-small cell lung cancer to EGFR-TKI [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3025.
Collapse
|
13
|
Lin YC, Wu MH, Wei TT, Lin YC, Huang WC, Huang LY, Lin YT, Chen CC. Correction: Metformin sensitizes anticancer effect of dasatinib in head and neck squamous cell carcinoma cells through AMPK-dependent ER stress. Oncotarget 2019; 10:3577-3578. [PMID: 31191828 PMCID: PMC6544396 DOI: 10.18632/oncotarget.26997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
|
14
|
Miaw SC, Lin YT, Hsu YH, Liu C, Chen CC, Shun CT, Tu CH, Yu JS, Wu MS, Chen CC. Phosphorylation of CBP by IKKα links intestinal homeostasis. THE JOURNAL OF IMMUNOLOGY 2019. [DOI: 10.4049/jimmunol.202.supp.117.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
CBP is a transcriptional coactivator participating in the regulation of DNA accessibility to transcription factors. Phosphorylation of human CBP by IKKα at serines 1382/1386 plays a critical role in regulating cell destiny via suppressing p53-mediated gene expression. We aimed to determine whether impaired phosphorylation of CBP is involved in the pathogenesis of disease. Hence, we designed and generated mutated serine 1383/1387 to alanine knockin mice (AA mice) to study whether they exhibit any phenotype alteration. AA mice showed an IBD-like phenotype with softer, looser and hemoccult stools and shorter colon length compared to the wild type mice. Increased p53 accompanied with apoptosis in colonic tissues of AA mice was demonstrated by IHC and TUNEL staining. In addition, male AA mice were more vulnerable to DSS-induced colitis with severe crypt loss and epithelial disruption. Elevated immune cells in mesenteric lymph nodes are also more prominent in AA mice with infiltration of neutrophil and macrophage. However, the differentiation of CD4+ T cells was not affected with Cbp mutation (AA) ex vivo. Colonic biopsies show that patients with ulcerative colitis have significantly lower phosphorylated CBP (Ser1382/1386) than healthy controls. Collectively, deficiency of NF-κB signaling in AA mice did not affect immune cells but modulated apoptosis of IECs. Our findings suggested that phosphorylation of CBP by IKKα might be a critical regulator to maintain intestinal homeostasis.
Collapse
|
15
|
Jiang LL, Chen CC, Yang K. Lessons learned from an unusual condition of incidental synchronous multiple hernias of indirect inguinal hernia, femoral hernia, and incarcerated obturator hernia. Niger J Clin Pract 2019; 22:281-284. [PMID: 30729956 DOI: 10.4103/njcp.njcp_200_18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Hernias are one of the most common diseases. The frequency of multiple hernias is much higher than the frequency reported during herniorrhaphy. Multiple hernias may account for some of the so-called recurrences, in which the small hernia may be veiled by the bigger one and omitted. In this study, we present a case of an 83-year-old female who suffered from multiple hernias namely a left-sided indirect inguinal hernia, a right-sided femoral hernia, and a right-sided incarcerated obturator hernia. Additionally, the characteristics and treatment of obturator hernia were discussed. Ultrasound and computed tomography (CT) are capable of accurately diagnosing groin hernia. Preoperative bilateral ultrasound of examinations or abdominopelvic CT should be recommended to perform routinely for patients with suspected hernias to avoid ignoring the concurrent hernias. A careful exploration of the operative field in the operation is mandatory. The CT is also helpful for early diagnosis of obturator hernia. In addition, the intra-abdominal approach through a low midline incision might be a preference for the treatment of obturator hernia.
Collapse
|
16
|
Chen Q, Chen CC, Bai J. Pathological Changes of Petechial Hemorrhage after High Temperature Treatment. FA YI XUE ZA ZHI 2019; 34:631-634. [PMID: 30896101 DOI: 10.12116/j.issn.1004-5619.2018.06.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Indexed: 11/30/2022]
Abstract
OBJECTIVES To study the main features of mechanical asphyxia--the pathological characteristics of petechial hemorrhage after high temperature effect (roasted, boiled) and its changing rules. METHODS Rabbit model of mechanical asphyxia death with choking neck and death from anteposition hanging was established. The experimental rabbits were randomly divided into roasted group and boiled group (n=4, in each group). The laryngeal ventricles and cardiopulmonary tissues in the roasted group were roasted for 3, 6 and 10 min, and the positions of petechial hemorrhage were observed and photographed. The same organs and tissues in the boiled group were heated in boiling water (100 ℃), and were observed and photographed at 30 and 60 s. Then histopathological examination was performed on all the laryngeal ventricles and cardiopulmonary tissues. RESULTS The petechial hemorrhage originating from laryngeal ventricle, trachea and lung did not disappear after high temperature treatment in the eight rabbits. The deepened color was visible to naked eyes and distinct from the surrounding normal tissues, with bleeding under the microscope. CONCLUSIONS Petechial hemorrhage caused by mechanical asphyxia would not disappear under high temperature, which might be related to the manner of death, the intensity and time of action, and the individual differences.
Collapse
|
17
|
Gorham PW, Rotter B, Allison P, Banerjee O, Batten L, Beatty JJ, Bechtol K, Belov K, Besson DZ, Binns WR, Bugaev V, Cao P, Chen CC, Chen CH, Chen P, Clem JM, Connolly A, Cremonesi L, Dailey B, Deaconu C, Dowkontt PF, Fox BD, Gordon JWH, Hast C, Hill B, Hughes K, Huang JJ, Hupe R, Israel MH, Javaid A, Lam J, Liewer KM, Lin SY, Liu TC, Ludwig A, Macchiarulo L, Matsuno S, Miki C, Mulrey K, Nam J, Naudet CJ, Nichol RJ, Novikov A, Oberla E, Olmedo M, Prechelt R, Prohira S, Rauch BF, Roberts JM, Romero-Wolf A, Russell JW, Saltzberg D, Seckel D, Schoorlemmer H, Shiao J, Stafford S, Stockham J, Stockham M, Strutt B, Varner GS, Vieregg AG, Wang SH, Wissel SA. Observation of an Unusual Upward-Going Cosmic-Ray-like Event in the Third Flight of ANITA. PHYSICAL REVIEW LETTERS 2018; 121:161102. [PMID: 30387639 DOI: 10.1103/physrevlett.121.161102] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 06/14/2018] [Indexed: 06/08/2023]
Abstract
We report on an upward traveling, radio-detected cosmic-ray-like impulsive event with characteristics closely matching an extensive air shower. This event, observed in the third flight of the Antarctic Impulsive Transient Antenna (ANITA), a NASA-sponsored long-duration balloon payload, is consistent with a similar event reported in a previous flight. These events could be produced by the atmospheric decay of an upward-propagating τ lepton produced by a ν_{τ} interaction, although their relatively steep arrival angles create tension with the standard model neutrino cross section. Each of the two events have a posteriori background estimates of ≲10^{-2} events. If these are generated by τ-lepton decay, then either the charged-current ν_{τ} cross section is suppressed at EeV energies, or the events arise at moments when the peak flux of a transient neutrino source was much larger than the typical expected cosmogenic background neutrinos.
Collapse
|
18
|
Liou JM, Chen PY, Luo JC, Lee JY, Chen CC, Fang YJ, Yang TH, Chang CY, Bair MJ, Chen MJ, Hsu YC, Hsu WF, Chang CC, Lin JT, Shun CT, El-Omar EM, Wu MS, Lee YC, Lin JT, Wu CY, Wu JY, Chen CC, Lin CH, Fang YR, Bair MJ, Luo JC, Wu MS, Cheng TY, Tseng PH, Chiu HM, Chang CC, Yu CC, Chiu MC, Chen YN, Hu WH, Chou CK, Tai CM, Lee CT, Wang WL, Chang WS. Efficacies of Genotypic Resistance-Guided vs Empirical Therapy for Refractory Helicobacter pylori Infection. Gastroenterology 2018; 155:1109-1119. [PMID: 29964036 DOI: 10.1053/j.gastro.2018.06.047] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 05/24/2018] [Accepted: 06/24/2018] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS We aimed to compare the efficacy of genotypic resistance-guided therapy vs empirical therapy for eradication of refractory Helicobacter pylori infection in randomized controlled trials. METHODS We performed 2 multicenter, open-label trials of patients with H pylori infection (20 years or older) failed by 2 or more previous treatment regimens, from October 2012 through September 2017 in Taiwan. The patients were randomly assigned to groups given genotypic resistance-guided therapy for 14 days (n = 21 in trial 1, n = 205 in trial 2) or empirical therapy according to medication history for 14 days (n = 20 in trial 1, n = 205 in trial 2). Patients received sequential therapy containing esomeprazole and amoxicillin for the first 7 days, followed by esomeprazole and metronidazole, with levofloxacin, clarithromycin, or tetracycline (doxycycline in trial 1, tetracycline in trial 2) for another 7 days (all given twice daily) based on genotype markers of resistance determined from gastric biopsy specimens (group A) or empirical therapy according to medication history. Resistance-associated mutations in 23S ribosomal RNA or gyrase A were identified by polymerase chain reaction with direct sequencing. Eradication status was determined by 13C-urea breath test. The primary outcome was eradication rate. RESULTS H pylori infection was eradicated in 17 of 21 (81%) patients receiving genotype resistance-guided therapy and 12 of 20 (60%) patients receiving empirical therapy (P = .181) in trial 1. This trial was terminated ahead of schedule due to the low rate of eradication in patients given doxycycline sequential therapy (15 of 26 [57.7%]). In trial 2, H pylori infection was eradicated in 160 of 205 (78%) patients receiving genotype resistance-guided therapy and 148 of 205 (72.2%) patients receiving empirical therapy (P = .170), according to intent to treat analysis. The frequencies of adverse effects and compliance did not differ significantly between groups. CONCLUSIONS Properly designed empirical therapy, based on medication history, is an acceptable alternative to genotypic resistance-guided therapy for eradication of refractory H pylori infection after consideration of accessibility, cost, and patient preference. ClinicalTrials.gov ID: NCT01725906.
Collapse
|
19
|
Wu VC, Chen SW, Wu M, Liu CH, Chang CW, Chen CC, Wu KP, Chang SH, Lin MS, Lee TH, Hsieh IC, Chu PH, Lin YS. P5138Resuming anticoagulation in patients with atrial fibrillation experiencing hemorrhage stroke or nontraumatic intracranial hemorrhage. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy566.p5138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
20
|
Liou JM, Chen CC, Fang YJ, Chen PY, Chang CY, Chou CK, Chen MJ, Tseng CH, Lee JY, Yang TH, Chiu MC, Yu JJ, Kuo CC, Luo JC, Hsu WF, Hu WH, Tsai MH, Lin JT, Shun CT, Twu G, Lee YC, Bair MJ, Wu MS, Liou JM, Lee YC, Lin JT, Wu CY, Wu JY, Chen CC, Lin CH, Fang YR, Bair MJ, Luo JC, Wu MS, Cheng TY, Tseng PH, Chiu HM, Chang CC, Yu CC, Chiu MC, Chen YN, Hu WH, Chou CK, Tai CM, Lee CT, Wang WL, Chang WS. 14 day sequential therapy versus 10 day bismuth quadruple therapy containing high-dose esomeprazole in the first-line and second-line treatment of Helicobacter pylori: a multicentre, non-inferiority, randomized trial. J Antimicrob Chemother 2018; 73:2510-2518. [DOI: 10.1093/jac/dky183] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Accepted: 04/18/2018] [Indexed: 12/12/2022] Open
|
21
|
Bao C, Wang XC, Hu XL, Hou DN, Chen CC, Song YL, Yang D. [Clinical manifestations analysis of patients diagnosed with primary pulmonary mucosa-associated lymphoid tissue lymphoma]. ZHONGHUA YI XUE ZA ZHI 2018; 98:1419-1423. [PMID: 29804405 DOI: 10.3760/cma.j.issn.0376-2491.2018.18.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To analyze the clinical features of pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma. Methods: A total of 14 cases diagnosed with primary pulmonary MALT lymphoma were collected from May 2007 to May 2017 in Zhongshan Hospital, Fudan University. The clinical features, pathological characteristics, diagnosis, treatment and prognosis were retrospectively analyzed. Results: All 14 cases were pathologically diagnosed with primary pulmonary MALT lymphoma. The biopsy tissues were obtained through the Video-assisted Thoracoscopic Surgery (VATS) (4 cases), percutaneous puncture (2 cases), and bronchoscopy (8 cases). Cell types of these tumors were centrocyte-like cells (10 cases), lymphocytoid cells (2 cases), and monocytoid B cells (2 cases). The B cell clonality was detected by IgH cloning test in 4 cases and 3 of them were demonstrated with monoclonal strips. MALT1 breakup gene was positive in 3 out of 6 examined cases using fluorescence in situ hybridization (FISH). As for the treatment, 8 patients underwent chemotherapy, 5 patients underwent surgical resection and 1 patient abandoned treatment. Twelve patients were followed up to 9 years. The tumor recurrence occurred in 2 patients and resulted their death. Conclusions: The clinical manifestations of primary pulmonary MALT lymphoma are lack of specificity. The pathology, immunohistochemistry, IgH cloning test and MALT1 breakup gene tested by FISH are the criteria for diagnosis.
Collapse
|
22
|
Lin Q, Ge XM, Mo JC, Li SS, Chen CC, Chen SY. [An investigation of psychological state at different stages of occupational AIDS exposure and related influencing factors in Nanning, China]. ZHONGHUA LAO DONG WEI SHENG ZHI YE BING ZA ZHI = ZHONGHUA LAODONG WEISHENG ZHIYEBING ZAZHI = CHINESE JOURNAL OF INDUSTRIAL HYGIENE AND OCCUPATIONAL DISEASES 2018; 34:762-764. [PMID: 28043249 DOI: 10.3760/cma.j.issn.1001-9391.2016.10.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To investigate the changes in psychological state after occupational exposure in the AIDS occupational exposure population and related influencing factors, and to provide baseline data and a basis for related departments to conduct mental health prevention and intervention for personnel with occupational AIDS exposure. Methods: AIDS risk assessment was performed for all personnel with occupational AIDS exposure in 2014 in Nanning, China, and the Symptom Checklist-90 (SCL-90) psychological scale was used for psychological state evaluation at 24 hours, 1 week, and 3 months after occupational exposure in all persons who met the research criteria. Results: Most of the persons with occupational AIDS exposure came from secondary and tertiary hospitals (85%) , and nurses accounted for the highest percentage (78.3% ). The age ranged from 21 to 50 years, and the mean age was 31.02 ± 7.92 years. The persons with occupational AIDS exposure aged 20~29 years accounted for the highest percentage (51.6%) , and most persons (76.7%) graduated from junior colleges. Compared with the adult norm, there was significant increases in the total psychological score and the number of positive items after occupational exposure (P<0.05). The scores of all items at 24 hours were significantly higher than those at the other time points, and the scores of all items gradually decreased over time (F=227.24, 267.57, and 287.46, P<0.05). Compared with the adult norm, there were significant increases in the factor points at 24 hours and significant reductions in the factor points at 3 months (P<0.05). Compared with those at 24 hours, the factor scores at 3 months decreased significantly (P<0.05). Conclusion: Occupational AIDS exposure affects the mental status of related personnel, and the mental status at 24 hours after exposure is poor. Related departments should provide corresponding psychological counseling for the occupational exposure population at different exposure times.
Collapse
|
23
|
Berglund JA, Gafni RI, Wodajo F, Cowen EW, El-Maouche D, Chang R, Chen CC, Guthrie LC, Molinolo AA, Collins MT. Tumor-induced osteomalacia in association with PTEN-negative Cowden syndrome. Osteoporos Int 2018; 29:993-997. [PMID: 29380000 PMCID: PMC7983154 DOI: 10.1007/s00198-017-4372-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 12/26/2017] [Indexed: 12/30/2022]
Abstract
Tumor-induced osteomalacia (TIO) is a rare paraneoplastic condition in which phosphaturic mesenchymal tumors (PMTs) secrete high levels of fibroblast growth factor 23 (FGF23) into the circulation. This results in renal phosphate wasting, hypophosphatemia, muscle weakness, bone pain, and pathological fractures. Recent studies suggest that fibronectin-fibroblast growth factor receptor 1 (FN1-FGFR1) translocations may be a driver of tumorigenesis. We present a patient with TIO who also exhibited clinical findings suggestive of Cowden syndrome (CS), a rare autosomal dominant disorder characterized by numerous benign hamartomas, as well as an increased risk for multiple malignancies, such as thyroid cancer. While CS is a clinical diagnosis, most, but not all, harbor a mutation in the tumor suppressor gene PTEN. Genetic testing revealed a somatic FN1-FGFR1 translocation in the FGF23-producing tumor causing TIO; however, a germline PTEN mutation was not identified. To our knowledge, this is the first reported case of concurrent TIO and CS.
Collapse
|
24
|
Chen WS, Liu LC, Yen CJ, Chen YJ, Chen JY, Ho CY, Liu SH, Chen CC, Huang WC. Nuclear IKKα mediates microRNA-7/-103/107/21 inductions to downregulate maspin expression in response to HBx overexpression. Oncotarget 2018; 7:56309-56323. [PMID: 27409165 PMCID: PMC5302916 DOI: 10.18632/oncotarget.10462] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 06/15/2016] [Indexed: 12/14/2022] Open
Abstract
Maspin is a tumor suppressor that stimulates apoptosis and inhibits metastasis in various cancer types, including hepatocellular carcinoma (HCC). Our previous study has demonstrated that HBx induced microRNA-7, 103, 107, and 21 expressions to suppress maspin expression, leading to metastasis, chemoresistance, and poor prognosis in HCC patients. However, it remains unclear how HBx elicits these microRNA expressions. HBx has been known to induce aberrant activation and nuclear translocation of inhibitor-κB kinase-α (IKKα) to promote HCC progression. In this study, our data further revealed that nuclear IKKα expression was inversely correlated with maspin expression in HBV-associated patients. Nuclear IKKα but not IKKβ reduced maspin protein and mRNA expression, and inhibition of IKKα reverses HBx-mediated maspin downregulation and chemoresistance. In response to HBx overexpression, nuclear IKKα was further demonstrated to induce the gene expressions of microRNA-7, −103, −107, and −21 by directly targeting their promoters, thereby leading to maspin downregulation. These findings indicated nuclear IKKα as a critical regulator for HBx-mediated microRNA induction and maspin suppression, and suggest IKKα as a promising target to improve the therapeutic outcome of HCC patients.
Collapse
|
25
|
Fanchiang YT, Chen KHM, Tseng CC, Chen CC, Cheng CK, Yang SR, Wu CN, Lee SF, Hong M, Kwo J. Strongly exchange-coupled and surface-state-modulated magnetization dynamics in Bi 2Se 3/yttrium iron garnet heterostructures. Nat Commun 2018; 9:223. [PMID: 29335558 PMCID: PMC5768741 DOI: 10.1038/s41467-017-02743-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2017] [Accepted: 12/20/2017] [Indexed: 12/03/2022] Open
Abstract
Harnessing the spin–momentum locking of topological surface states in conjunction with magnetic materials is the first step to realize novel topological insulator-based devices. Here, we report strong interfacial coupling in Bi2Se3/yttrium iron garnet (YIG) bilayers manifested as large interfacial in-plane magnetic anisotropy (IMA) and enhancement of damping probed by ferromagnetic resonance. The interfacial IMA and damping enhancement reaches a maximum when the Bi2Se3 film approaches its two-dimensional limit, indicating that topological surface states play an important role in the magnetization dynamics of YIG. Temperature-dependent ferromagnetic resonance of Bi2Se3/YIG reveals signatures of the magnetic proximity effect of TC as high as 180 K, an emerging low-temperature perpendicular magnetic anisotropy competing the high-temperature IMA, and an increasing exchange effective field of YIG steadily increasing toward low temperature. Our study sheds light on the effects of topological insulators on magnetization dynamics, essential for the development of topological insulator-based spintronic devices. Understanding the effects of topological insulators on magnetization dynamics of adjacent magnetic materials is essential for novel spintronic devices. Here, Fanchiang et al. report thickness dependence of interfacial in-plane magnetic anisotropy and damping enhancement in Bi2Se3/yttrium iron garnet (YIG) bilayers, indicating an important role of topological surface states in the magnetization dynamics of YIG.
Collapse
|