1
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Sharma SK, Schilke AR, Phan JR, Yip C, Sharma PV, Abel-Santos E, Firestine SM. The design, synthesis, and inhibition of Clostridioides difficile spore germination by acyclic and bicyclic tertiary amide analogs of cholate. Eur J Med Chem 2023; 261:115788. [PMID: 37703709 PMCID: PMC10680100 DOI: 10.1016/j.ejmech.2023.115788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 08/30/2023] [Accepted: 08/31/2023] [Indexed: 09/15/2023]
Abstract
Clostridioides difficile infection (CDI) is a major identifiable cause of antibiotic-associated diarrhea. In our previous study (J. Med. Chem., 2018, 61, 6759-6778), we have identified N-phenyl-cholan-24-amide as a potent inhibitor of spore germination. The most potent compounds in our previous work are N-arylamides. We were interested in the role that the conformation of the amide plays in activity. Previous research has shown that secondary N-arylamides exist exclusively in the coplanar trans conformation while tertiary N-methyl-N-arylamides exist in a non-planar, cis conformation. The N-methyl-N-phenyl-cholan-24-amide was 17-fold less active compared to the parent compounds suggesting the importance of the orientation of the phenyl ring. To lock the phenyl ring into a trans conformation, cyclic tertiary amides were prepared. Indoline and quinoline cholan-24-amides were both inhibitors of spore germination; however, the indoline analogs were most potent. Isoindoline and isoquinoline amides were inactive. We found that the simple indoline derivative gave an IC50 value of 1 μM, while the 5'-fluoro-substituted compound (5d) possessed an IC50 of 400 nM. To our knowledge, 5d is the most potent known spore germination inhibitor described to date. Taken together, our results indicate that the trans, coplanar conformation of the phenyl ring is required for potent inhibition.
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Affiliation(s)
- Shiv K Sharma
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, 259 Mack Avenue, Detroit, MI, 48201, USA
| | - Angel R Schilke
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, 259 Mack Avenue, Detroit, MI, 48201, USA
| | - Jacqueline R Phan
- Department of Chemistry and Biochemistry, University of Nevada -Las Vegas, 4505 S. Maryland Pkwy, Las Vegas, NV, 89154, USA
| | - Christopher Yip
- Department of Chemistry and Biochemistry, University of Nevada -Las Vegas, 4505 S. Maryland Pkwy, Las Vegas, NV, 89154, USA
| | - Prateek V Sharma
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, 259 Mack Avenue, Detroit, MI, 48201, USA
| | - Ernesto Abel-Santos
- Department of Chemistry and Biochemistry, University of Nevada -Las Vegas, 4505 S. Maryland Pkwy, Las Vegas, NV, 89154, USA
| | - Steven M Firestine
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, 259 Mack Avenue, Detroit, MI, 48201, USA.
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2
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Yip C, Phan JR, Abel-Santos E. Mechanism of germination inhibition of Clostridioides difficile spores by an aniline substituted cholate derivative (CaPA). J Antibiot (Tokyo) 2023; 76:335-345. [PMID: 37016015 PMCID: PMC10406169 DOI: 10.1038/s41429-023-00612-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 02/28/2023] [Accepted: 03/07/2023] [Indexed: 04/06/2023]
Abstract
Clostridioides difficile infection (CDI) is the major identifiable cause of antibiotic-associated diarrhea and has been declared an urgent threat by the CDC. C. difficile forms dormant and resistant spores that serve as infectious vehicles for CDI. To cause disease, C. difficile spores recognize taurocholate and glycine to trigger the germination process. In contrast to other sporulating bacteria, C. difficile spores are postulated to use a protease complex, CspABC, to recognize its germinants. Since spore germination is required for infection, we have developed anti-germination approaches for CDI prophylaxis. Previously, the bile salt analog CaPA (an aniline-substituted cholic acid) was shown to block spore germination and protect rodents from CDI caused by multiple C. difficile strains and isolates. In this study, we found that CaPA is an alternative substrate inhibitor of C. difficile spore germination. By competing with taurocholate for binding, CaPA delays C. difficile spore germination and reduces spore viability, thus diminishing the number of outgrowing vegetative bacteria. We hypothesize that the reduction of toxin-producing bacterial burden explains CaPA's protective activity against murine CDI. Previous data combined with our results suggests that CaPA binds tightly to C. difficile spores in a CspC-dependent manner and irreversibly traps spores in an alternative, time-delayed, and low yield germination pathway. Our results are also consistent with kinetic data suggesting the existence of at least two distinct bile salt binding sites in C. difficile spores.
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Affiliation(s)
- Christopher Yip
- Department of Chemistry and Biochemistry, University of Nevada, Las Vegas, NV, 89154, USA
| | - Jacqueline R Phan
- Department of Chemistry and Biochemistry, University of Nevada, Las Vegas, NV, 89154, USA
| | - Ernesto Abel-Santos
- Department of Chemistry and Biochemistry, University of Nevada, Las Vegas, NV, 89154, USA.
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3
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Yeo W, Ngai N, Yip C, Yeo V, Ko J, Yip C, Mo F. Abstract P3-03-03: Risk factors associated with chemotherapy-induced nausea and vomiting among breast cancer patients receiving highly emetogenic chemotherapy. Cancer Res 2023. [DOI: 10.1158/1538-7445.sabcs22-p3-03-03] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
Abstract
Purpose: Although risk factors related to chemotherapy-induced nausea and vomiting (CINV) have been identified by prior studies, there are only few studies evaluating risk factors associated with the contemporary antiemetic prophylaxis, including that of olanzapine/aprepitant- or NEPA- containing regimens. The present study aimed to identify the risk factors related to CINV development in Chinese breast cancer patients receiving doxorubicin and cyclophosphamide chemotherapy. Methods: Data from 304 patients who were enrolled to 3 previously reported prospective antiemetic studies were included. Multivariate logistic regression models were used to predict risk factors associated with the occurrence of CINV. Additionally, likelihood of treatment failure in relation to number of risk factors of individual patient was evaluated. Results: Multivariate analysis of the entire study group revealed that obese status (defined as body mass index >/= 25.0 kg/m2) and the use of olanzapine/aprepitant- or NEPA- containing antiemetic regimens were associated with high likelihood, while history of motion sickness was associated with lower likelihood, of complete response (CR) and ‘no nausea’ in the overall phase. History of vomiting in pregnancy was also associated with lower likelihood of overall CR. Patients with increasing number of risk factors had higher likelihood of treatment failure as well as shorter time to first vomiting. Those who did not achieve CR and ‘no nausea’ in the first cycle were less likely to achieve these parameters in the subsequent cycle of chemotherapy. Conclusions: This present study confirmed the previously reported risk factors to be important for CINV in Chinese breast cancer patients receiving doxorubicin and cyclophosphamide. Further optimization of CINV control is required for patients with identifiable risk factors; olanzapine/aprepitant- or NEPA- containing prophylaxes are the preferred contemporary antiemetics regimens for Chinese breast cancer patients undergoing doxorubicin and cyclophosphamide chemotherapy.
Citation Format: Winnie Yeo, Nicole Ngai, Christopher Yip, Victoria Yeo, Jonathan Ko, Claudia Yip, Frankie Mo. Risk factors associated with chemotherapy-induced nausea and vomiting among breast cancer patients receiving highly emetogenic chemotherapy [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-03-03.
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Affiliation(s)
| | | | | | | | - Jonathan Ko
- 5Royal College of Physicians and Surgeons of Ireland School of Medicine
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4
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Chua K, Tan A, Saw S, Lai G, Tan W, Jain A, Rajasekaran T, Chia B, Li Y, Fong K, Siow T, Ng Q, Thiagarajan A, Kanesvaran R, Ng W, Yap S, Kalashnikova E, Aleshin A, Skanderup A, Lim WT, Yip C, Tan S, Tan D, Ang MK. P2.13-02 Dynamic Tracking of Bespoke Circulating Tumour DNA During Multi-Modality Therapy for Locally Advanced NSCLC (LA-NSCLC). J Thorac Oncol 2022. [DOI: 10.1016/j.jtho.2022.07.255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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5
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Teng A, Gu L, Di Paola M, Lakin R, Williams Z, Au A, CHEN WENLIANG, Callaghan NI, Hakem Zadeh F, ZHOU YUQING, Fatah M, Chatterjee D, Jourdan J, Jack L, Simmons CA, Kislinger T, Yip C, Backx P, Gourdie RG, Hamilton RM, Gramolini A. Abstract P2018: Tmem65 Is Critical For The Structure And Function Of The Intercalated Discs In Mouse Hearts. Circ Res 2022. [DOI: 10.1161/res.131.suppl_1.p2018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The intercalated disc (ICD) is unique membrane structure that is indispensable to normal heart function, yet its structural organization is not completely understood. Previously, we showed that the ICD-bound transmembrane protein 65 (Tmem65) was required for connexin 43 (Cx43) localization and function in cultured mouse neonatal cardiomyocytes. Here, we investigated the role of Tmem65 in ICD organization
in vivo
. A mouse model was established by injecting CD1 mouse pups (3-7 days after birth) with recombinant adeno-associated virus 9 (rAAV9) harboring Tmem65 shRNA which resulted in a 90% reduction of Tmem65 expression in mouse ventricles compared to mice injected with scrambled shRNA. Tmem65 knockdown (KD) resulted in increased mortality which was accompanied by eccentric hypertrophic cardiomyopathy within 3 weeks of injection, progressing to dilated cardiomyopathy with severe cardiac fibrosis by 7 weeks post-injection. Tmem65 KD hearts displayed depressed hemodynamics, measured echocardiographically, accompanied by electrocardiogram changes (prolonged PR intervals and QRS duration) consistent with impaired conduction, which was confirmed with optical mapping of isolated hearts. Immunoprecipitation and super-resolution microscopy demonstrated a physical interaction between Tmem65 and sodium channel β subunit (β1) in mouse hearts and this interaction appeared to be required for both the establishment of perinexal nanodomain structure and the localization of both voltage-gated sodium channel 1.5 (NaV1.5) and Cx43 to ICDs. Despite the loss of NaV1.5 at the ICDs, whole-cell patch clamp electrophysiology did not reveal reductions in Na
+
currents but did show reduced Ca
2+
and K
+
currents in Tmem65 KD cardiomyocytes in comparison to control cells. We conclude that disrupting Tmem65 function results in impaired ICD structure, abnormal cardiac electrophysiology, and ultimately cardiomyopathy.
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Affiliation(s)
| | | | | | | | | | - Aaron Au
- Univ of Toronto, Toronto, Canada
| | | | | | | | | | | | | | | | - Liu Jack
- Univ of Toronto, Toronto, Canada
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6
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He X, Tolosa MF, Zhang T, Goru SK, Ulloa Severino L, Misra PS, McEvoy CM, Caldwell L, Szeto SG, Gao F, Chen X, Atin C, Ki V, Vukosa N, Hu C, Zhang J, Yip C, Krizova A, Wrana JL, Yuen DA. Myofibroblast YAP/TAZ activation is a key step in organ fibrogenesis. JCI Insight 2022; 7:146243. [PMID: 35191398 PMCID: PMC8876427 DOI: 10.1172/jci.insight.146243] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 01/12/2022] [Indexed: 12/13/2022] Open
Abstract
Fibrotic diseases account for nearly half of all deaths in the developed world. Despite its importance, the pathogenesis of fibrosis remains poorly understood. Recently, the two mechanosensitive transcription cofactors YAP and TAZ have emerged as important profibrotic regulators in multiple murine tissues. Despite this growing recognition, a number of important questions remain unanswered, including which cell types require YAP/TAZ activation for fibrosis to occur and the time course of this activation. Here, we present a detailed analysis of the role that myofibroblast YAP and TAZ play in organ fibrosis and the kinetics of their activation. Using analyses of cells, as well as multiple murine and human tissues, we demonstrated that myofibroblast YAP and TAZ were activated early after organ injury and that this activation was sustained. We further demonstrated the critical importance of myofibroblast YAP/TAZ in driving progressive scarring in the kidney, lung, and liver, using multiple transgenic models in which YAP and TAZ were either deleted or hyperactivated. Taken together, these data establish the importance of early injury-induced myofibroblast YAP and TAZ activation as a key event driving fibrosis in multiple organs. This information should help guide the development of new antifibrotic YAP/TAZ inhibition strategies.
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Affiliation(s)
- Xiaolin He
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital (Unity Health Toronto) and Department of Medicine, and
| | - Monica F Tolosa
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital (Unity Health Toronto) and Department of Medicine, and
| | - Tianzhou Zhang
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital (Unity Health Toronto) and Department of Medicine, and
| | - Santosh Kumar Goru
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital (Unity Health Toronto) and Department of Medicine, and
| | - Luisa Ulloa Severino
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital (Unity Health Toronto) and Department of Medicine, and
| | - Paraish S Misra
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital (Unity Health Toronto) and Department of Medicine, and
| | - Caitríona M McEvoy
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital (Unity Health Toronto) and Department of Medicine, and
| | - Lauren Caldwell
- Center for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital and Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Stephen G Szeto
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital (Unity Health Toronto) and Department of Medicine, and
| | - Feng Gao
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital (Unity Health Toronto) and Department of Medicine, and.,Department of Pathology, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei, People's Republic of China
| | - Xiaolan Chen
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital (Unity Health Toronto) and Department of Medicine, and.,Department of Respiratory and Critical Care Medicine, Beijing Shijitan Hospital, Capital Medical University, Beijing, People's Republic of China
| | - Cassandra Atin
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital (Unity Health Toronto) and Department of Medicine, and
| | - Victoria Ki
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital (Unity Health Toronto) and Department of Medicine, and
| | - Noah Vukosa
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital (Unity Health Toronto) and Department of Medicine, and
| | - Catherine Hu
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital (Unity Health Toronto) and Department of Medicine, and
| | - Johnny Zhang
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital (Unity Health Toronto) and Department of Medicine, and
| | - Christopher Yip
- Faculty of Applied Science and Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Adriana Krizova
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital (Unity Health Toronto) and Department of Medicine, and.,Department of Laboratory Medicine and Pathobiology, St. Michael's Hospital (Unity Health Toronto) and University of Toronto, Toronto, Ontario, Canada
| | - Jeffrey L Wrana
- Center for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital and Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Darren A Yuen
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital (Unity Health Toronto) and Department of Medicine, and
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7
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Sharma SK, Yip C, Simon MP, Phan J, Abel-Santos E, Firestine SM. Studies on the Importance of the 7α-, and 12α- hydroxyl groups of N-Aryl-3α,7α,12α-trihydroxy-5β-cholan-24-amides on their Antigermination Activity Against a Hypervirulent Strain of Clostridioides (Clostridium) difficile. Bioorg Med Chem 2021; 52:116503. [PMID: 34837818 DOI: 10.1016/j.bmc.2021.116503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 10/19/2021] [Accepted: 11/02/2021] [Indexed: 10/19/2022]
Abstract
Chenodeoxycholic acid (CDCA) is a natural germination inhibitor for C. difficile spores. In our previous study (J. Med. Chem., 2018, 61, 6759-6778), we identified N-phenyl-3α,7α,12α-trihydroxy-5β-cholan-24-amide as an inhibitor of C. difficile strain R20291 with an IC50 of 1.8 μM. Studies of bile salts on spore germination have shown that chenodeoxycholate, ursodeoxycholate and lithocholate are more potent inhibitors of germination compared to cholate. Given this, we created amide analogs of chenodeoxycholic, deoxycholic, lithocholic and ursodeoxycholic acids using amines identified from our previous studies. We found that chenodeoxy- and deoxycholate derivatives were active with potencies equivalent to those for cholanamides. This indicates that only 2 out of the 3 hydroxyl groups are needed for activity and that the alpha stereochemistry at position 7 is required for inhibition of spore germination.
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Affiliation(s)
- Shiv K Sharma
- Department of Pharmaceutical sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, 259 Mack Avenue, Detroit, MI 48201, United States
| | - Christopher Yip
- Department of Chemistry and Biochemistry, University of Nevada at Las Vegas, 4505 S. Maryland Pkwy., Las Vegas, NV, 89154, United States
| | - Matthew P Simon
- Department of Pharmaceutical sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, 259 Mack Avenue, Detroit, MI 48201, United States
| | - Jacqueline Phan
- Department of Chemistry and Biochemistry, University of Nevada at Las Vegas, 4505 S. Maryland Pkwy., Las Vegas, NV, 89154, United States
| | - Ernesto Abel-Santos
- Department of Chemistry and Biochemistry, University of Nevada at Las Vegas, 4505 S. Maryland Pkwy., Las Vegas, NV, 89154, United States
| | - Steven M Firestine
- Department of Pharmaceutical sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, 259 Mack Avenue, Detroit, MI 48201, United States.
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8
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Teng AC, Gu L, Di Paola M, Williams Z, Au A, Callaghan N, Hakem Zadeh F, Zhao YQ, Fatah M, Chatterjee D, Jourdan JJ, Simmons CA, Kislinger T, Yip C, Gourdie RG, Hamilton RM, Gramolini A. Abstract P361: Reduced Cardiac Tmem65 In Mouse Hearts Results In Intercalated Disc Defects And Eventual Dilated Cardiomyopathy With Cardiac Fibrosis. Circ Res 2021. [DOI: 10.1161/res.129.suppl_1.p361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The intercalated disc (ICD) is unique membrane structure that is indispensable to normal heart function. However, its structural organization is not well understood. Previously, we showed that the ICD-bound transmembrane protein 65 (Tmem65) was required for connexin 43 (Cx43) localization in cultured mouse neonatal cardiomyocytes. Here, we investigated the role of Tmem65 in ICD organization
in vivo
. A mouse model was established by injecting CD1 mouse pups (3-7 days after birth) with recombinant adeno-associated virus 9 (rAAV9) harboring Tmem65 (or scrambled) shRNA. Quantitative polymerase chain reaction (qPCR) and immunoblots confirmed greater than 85% reduction in Tmem65 expression (7.1±0.7% remained for Tmem65 proteins; 14.4±2.5% remained for Tmem65 transcripts,
n
=4) in mouse ventricles compared to control hearts. Tmem65 knockdown (KD) mice exhibited heart failure-like symptoms as early as 3 weeks post viral administration. Specifically, Tmem65 KD mice developed eccentric hypertrophic cardiomyopathy in 3 weeks and dilated cardiomyopathy with severe cardiac fibrosis in 7 weeks, as confirmed by H&E and Masson’s Trichrome staining. Echocardiography and electrocardiography, respectively, showed depressed hemodynamics (19.27±1.46ml/min for cardiac output in control hearts vs. 6.63±0.52ml/min for Tmem65 KD hearts,
n
=6) and impaired conduction, including prolonged PR (22.7±1.85ms in control hearts vs. 28.89±3.85ms in Tmem65 KD hearts, n≥8), QRS intervals (10.47±0.42ms in control hearts vs. 16.35±0.36ms in Tmem65 KD hearts, n≥8), and slowed heart rate (415±10bpm in control hearts vs. 347±16bpm in Tmem65 KD hearts, n≥8) in Tmem65 KD mouse hearts.
Immunoprecipitation and super-resolution microscopy confirmed the physical interaction and localization between Tmem65 and voltage-gated sodium channel β subunit (β1) at the ICD and this interaction was evidently required for the establishment of perinexal nanodomains and voltage-gated sodium channel 1.5 (NaV1.5) localization to the ICD. Disrupting Tmem65 function, thus, impaired perinexal structure, reduced conduction velocity, and ultimately resulted in cardiomyopathy
in vivo
.
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Affiliation(s)
| | | | | | | | - Aaron Au
- Univ of Toronto, Toronto, Canada
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9
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Van Cutsem E, Dixon M, Taylor F, Sun X, Yip C, Blum S. 437P Quality of life (QoL) in patients (pts) with microsatellite instability (MSI-H) or mismatch repair deficient (dMMR) metastatic colorectal cancer (mCRC) treated with nivolumab (NIVO) alone or in combination with ipilimumab (IPI): CheckMate 142. Ann Oncol 2021. [DOI: 10.1016/j.annonc.2021.08.958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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10
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Owczarczyk K, Withey S, Grzeda M, Yip C, Qureshi A, Gossage J, Davies A, Cook G, Goh V. P-284 Exploratory magnetic resonance imaging histogram biomarkers for response prediction to neoadjuvant treatment in oesophageal/gastro-oesophageal cancer. Ann Oncol 2021. [DOI: 10.1016/j.annonc.2021.05.338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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11
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Olevsko I, Szederkenyi K, Corridon J, Au A, Delhomme B, Bastien T, Fernandes J, Yip C, Oheim M, Salomon A. A simple, inexpensive and multi-scale 3-D fluorescent test sample for optical sectioning microscopies. Microsc Res Tech 2021; 84:2625-2635. [PMID: 34008289 DOI: 10.1002/jemt.23813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 04/05/2021] [Accepted: 04/27/2021] [Indexed: 11/11/2022]
Abstract
Fluorescence standards allow for quality control and for the comparison of data sets across instruments and laboratories in applications of quantitative fluorescence. For example, users of microscopy core facilities can expect a homogenous and time-invariant illumination and an uniform detection sensitivity, which are prerequisites for imaging analysis, tracking or fluorimetric pH or Ca2+ -concentration measurements. Similarly, confirming the three-dimensional (3-D) resolution of optical sectioning microscopes calls for a regular calibration with a standardized point source. The test samples required for such measurements are typically different ones, they are often expensive and they depend much on the very microscope technique used. Similarly, the ever-increasing choice among microscope techniques and geometries increases the demand for comparison across instruments. Here, we advocate and demonstrate the multiple uses of a surprisingly versatile and simple 3-D test sample that can complement existing and much more expensive calibration samples: commercial tissue paper labeled with a fluorescent highlighter pen. We provide relevant sample characteristics and show examples ranging from the sub-μm to cm scale, acquired on epifluorescence, confocal, image scanning, two-photon (2P) and light-sheet microscopes.
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Affiliation(s)
- Ilya Olevsko
- Department of Chemistry, Bar-Ilan University, Institute of Nanotechnology and Advanced Materials (BINA), Ramat-Gan, Israel
| | - Kaitlin Szederkenyi
- Université de Paris, CNRS, SPPIN - Saints-Pères Paris Institute for the Neurosciences, Paris, France.,University of Toronto, Donnelly Centre for Cellular & Biomolecular Research, Toronto, Ontario, Canada
| | - Jennifer Corridon
- Université de Paris, CNRS UMS 2009, INSERM US 36, BioMedTech Facilities, Paris, France.,Université de Paris, Service Commun de Microscopie (SCM), Paris, France
| | - Aaron Au
- University of Toronto, Donnelly Centre for Cellular & Biomolecular Research, Toronto, Ontario, Canada
| | - Brigitte Delhomme
- Université de Paris, CNRS, SPPIN - Saints-Pères Paris Institute for the Neurosciences, Paris, France
| | - Thierry Bastien
- Université de Paris, CNRS UMS 2009, INSERM US 36, BioMedTech Facilities, Paris, France.,Université de Paris, Plateforme de Prototypage, Paris, France
| | - Julien Fernandes
- UTechS Photonic BioImaging, C2RT, Institut Pasteur, Paris, France
| | - Christopher Yip
- University of Toronto, Donnelly Centre for Cellular & Biomolecular Research, Toronto, Ontario, Canada
| | - Martin Oheim
- Université de Paris, CNRS, SPPIN - Saints-Pères Paris Institute for the Neurosciences, Paris, France.,Université de Paris, CNRS UMS 2009, INSERM US 36, BioMedTech Facilities, Paris, France.,Université de Paris, Service Commun de Microscopie (SCM), Paris, France
| | - Adi Salomon
- Department of Chemistry, Bar-Ilan University, Institute of Nanotechnology and Advanced Materials (BINA), Ramat-Gan, Israel.,Université de Paris, CNRS, SPPIN - Saints-Pères Paris Institute for the Neurosciences, Paris, France
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12
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Yip C, Okada NC, Howerton A, Amei A, Abel-Santos E. Pharmacokinetics of CamSA, a potential prophylactic compound against Clostridioides difficile infections. Biochem Pharmacol 2021; 183:114314. [PMID: 33152344 PMCID: PMC7770080 DOI: 10.1016/j.bcp.2020.114314] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/28/2020] [Accepted: 10/29/2020] [Indexed: 12/30/2022]
Abstract
Clostridioides difficile infections (CDI) are the leading cause of nosocomial antibiotic-associated diarrhea. C. difficile produces dormant spores that serve as infectious agents. Bile salts in the gastrointestinal tract signal spores to germinate into toxin-producing cells. As spore germination is required for CDI onset, anti-germination compounds may serve as prophylactics. CamSA, a synthetic bile salt, was previously shown to inhibit C. difficile spore germination in vitro and in vivo. Unexpectedly, a single dose of CamSA was sufficient to offer multi-day protection from CDI in mice without any observable toxicity. To study this intriguing protection pattern, we examined the pharmacokinetic parameters of CamSA. CamSA was stable to the gut of antibiotic-treated mice but was extensively degraded by the microbiota of non-antibiotic-treated animals. Our data also suggest that CamSA's systemic absorption is minimal since it is retained primarily in the intestinal lumen and liver. CamSA shows weak interactions with CYP3A4, a P450 hepatic isozyme involved in drug metabolism and bile salt modification. Like other bile salts, CamSA seems to undergo enterohepatic circulation. We hypothesize that the cycling of CamSA between the liver and intestines serves as a slow-release mechanism that allows CamSA to be retained in the gastrointestinal tract for days. This model explains how a single CamSA dose can prevent murine CDI even though spores are present in the animal's intestine for up to four days post-challenge.
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Affiliation(s)
- Christopher Yip
- Department of Chemistry and Biochemistry, University of Nevada, Las Vegas, 4505 S. Maryland Parkway, Las Vegas, Nevada 89154, United States
| | - Naomi C Okada
- Department of Chemistry and Biochemistry, University of Nevada, Las Vegas, 4505 S. Maryland Parkway, Las Vegas, Nevada 89154, United States
| | - Amber Howerton
- Department of Physical and Life Sciences, Nevada State College, 1300 Nevada State Drive, Henderson, Nevada, 89002, United States
| | - Amei Amei
- Department of Mathematical Sciences, University of Nevada, Las Vegas, 4505 S. Maryland Parkway, Las Vegas, Nevada 89154, United States
| | - Ernesto Abel-Santos
- Department of Chemistry and Biochemistry, University of Nevada, Las Vegas, 4505 S. Maryland Parkway, Las Vegas, Nevada 89154, United States.
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Yip C, Yeong J, Leow W, Wang L, Lee L, Lim T, Siow T, Lim F, Wang M, Ho S, Wang F, Ng M, Ong S, Lam J, Wong W, Ong H, Lim E, Eng A, Lim C, Chan W, Wong A, Lee J, Lin J, Ong E, Chua M. PO-1034: Chemoradiation-induced intratumoral immune microenvironment changes in oesophageal cancer. Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)01051-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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14
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Yeo W, Li L, Lau T, Lai K, Chan V, Wong K, Yip C, Pang E, Cheung M, Chan V, Kwok C, Suen J, Mo F. Evaluation of optimal prophylactic antiemetic regimens for doxorubicin-cyclophosphamide chemotherapy. Eur J Cancer 2020. [DOI: 10.1016/s0959-8049(20)30869-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Ahmed U, Iwasa SN, Poloni L, Ahlfors JE, Yip C, Popovic MR, Morshead CM. Substrate-Dependent Galvanotaxis of Directly Reprogrammed Human Neural Precursor Cells. Bioelectricity 2020; 2:229-237. [PMID: 34476355 DOI: 10.1089/bioe.2019.0037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Background: Neural precursor cells (NPCs) hold great promise for neural repair. Endogenous NPCs, found in the subventricular zone of the adult brain, proliferate and migrate toward lesion sites; however, it is not sufficient for neural repair. NPCs are electrosensitive cells that undergo directed migration in an electric field (EF). Here, we examined the EF-induced migration of a clinically relevant human NPC population. Materials & Methods: We examined the effects of different substrates and microenvironments on human NPC galvanotaxis. Results: Human NPCs increased their migration speed in the presence of an EF, and the direction of migration (anodal vs. cathodal) varied between substrates. The secretome and extracellular pH were not significant factors in EF-induced migration; however, our results are consistent with substrate stiffness playing a role in the direction of cell migration. Conclusion: These findings provide insight into the importance of the microenvironment on modulating human NPC migration and highlight substrate-dependent considerations for neurorepair.
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Affiliation(s)
- Umalkhair Ahmed
- Institute of Biomaterials and Biomedical Engineering, Departments of University of Toronto, Toronto, Canada
| | | | - Laura Poloni
- Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Canada
| | | | - Christopher Yip
- Institute of Biomaterials and Biomedical Engineering, Departments of University of Toronto, Toronto, Canada.,Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Canada
| | - Milos R Popovic
- Institute of Biomaterials and Biomedical Engineering, Departments of University of Toronto, Toronto, Canada.,KITE Toronto Rehabilitation Institute, University Health Network, Toronto, Canada
| | - Cindi M Morshead
- Institute of Biomaterials and Biomedical Engineering, Departments of University of Toronto, Toronto, Canada.,Surgery and University of Toronto, Toronto, Canada.,KITE Toronto Rehabilitation Institute, University Health Network, Toronto, Canada
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Yip C, Payne E, Noel-MacDonnell J, Anderson J, Robinson A, Reading B, Cully B, Bolger Theut S, Rivard D. Abstract No. 622 Evaluation of the efficacy of image-guided pain management procedures on pediatric patients. J Vasc Interv Radiol 2020. [DOI: 10.1016/j.jvir.2019.12.683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Knight WRC, Yip C, Wulaningsih W, Jacques A, Griffin N, Zylstra J, Van Hemelrijck M, Maisey N, Gaya A, Baker CR, Kelly M, Gossage JA, Lagergren J, Landau D, Goh V, Davies AR, Ngan S, Qureshi A, Deere H, Green M, Chang F, Mahadeva U, Gill‐Barman B, George S, Dunn J, Zeki S, Meenan J, Hynes O, Tham G, Iezzi C. Prediction of a positive circumferential resection margin at surgery following neoadjuvant chemotherapy for adenocarcinoma of the oesophagus. BJS Open 2019; 3:767-776. [PMID: 31832583 PMCID: PMC6887675 DOI: 10.1002/bjs5.50211] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 06/24/2019] [Indexed: 02/06/2023] Open
Abstract
Background A positive circumferential resection margin (CRM) has been associated with higher rates of locoregional recurrence and worse survival in oesophageal cancer. The aim of this study was to establish if clinicopathological and radiological variables might predict CRM positivity in patients who received neoadjuvant chemotherapy before surgery for oesophageal adenocarcinoma. Methods Multivariable analysis of clinicopathological and CT imaging characteristics considered potentially predictive of CRM was performed at initial staging and following neoadjuvant chemotherapy. Prediction models were constructed. The area under the curve (AUC) with 95% confidence intervals (c.i.) from 1000 bootstrapping was assessed. Results A total of 223 patients were included in the study. Poor differentiation (odds ratio (OR) 2·84, 95 per cent c.i. 1·39 to 6·01) and advanced clinical tumour status (T3-4) (OR 2·93, 1·03 to 9·48) were independently associated with an increased CRM risk at diagnosis. CT-assessed lack of response (stable or progressive disease) following chemotherapy independently corresponded with an increased risk of CRM positivity (OR 3·38, 1·43 to 8·50). Additional CT evidence of local invasion and higher CT tumour volume (14 cm3) improved the performance of a prediction model, including all the above parameters, with an AUC (c-index) of 0·76 (0·67 to 0·83). Variables associated with significantly higher rates of locoregional recurrence were pN status (P = 0·020), lymphovascular invasion (P = 0·007) and poor response to chemotherapy (Mandard score 4-5) (P = 0·006). CRM positivity was associated with a higher locoregional recurrence rate, but this was not statistically significant (P = 0·092). Conclusion The presence of advanced cT status, poor tumour differentiation, and CT-assessed lack of response to chemotherapy, higher tumour volume and local invasion can be used to identify patients at risk of a positive CRM following neoadjuvant chemotherapy.
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Affiliation(s)
- W. R. C. Knight
- Department of Surgery, Guy's and St Thomas' Oesophago‐Gastric Centre, King's College London
- School of Cancer and Pharmaceutical Sciences, King's College London
| | - C. Yip
- School of Biomedical Engineering and Imaging Sciences, King's College London
| | - W. Wulaningsih
- Cancer Epidemiology and Population Health Associated Research Group, King's College London
| | - A. Jacques
- Department of Radiology, Guy's and St Thomas' Hospital, London, UK
| | - N. Griffin
- Department of Radiology, Guy's and St Thomas' Hospital, London, UK
| | - J. Zylstra
- Department of Surgery, Guy's and St Thomas' Oesophago‐Gastric Centre, King's College London
| | - M. Van Hemelrijck
- Cancer Epidemiology and Population Health Associated Research Group, King's College London
| | - N. Maisey
- Department of Oncology, Guy's and St Thomas' Hospital, London, UK
| | - A. Gaya
- Department of Oncology, Guy's and St Thomas' Hospital, London, UK
| | - C. R. Baker
- Department of Surgery, Guy's and St Thomas' Oesophago‐Gastric Centre, King's College London
| | - M. Kelly
- Department of Surgery, Guy's and St Thomas' Oesophago‐Gastric Centre, King's College London
| | - J. A. Gossage
- Department of Surgery, Guy's and St Thomas' Oesophago‐Gastric Centre, King's College London
- School of Cancer and Pharmaceutical Sciences, King's College London
- Upper Gastrointestinal Surgery, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - J. Lagergren
- Department of Surgery, Guy's and St Thomas' Oesophago‐Gastric Centre, King's College London
- School of Cancer and Pharmaceutical Sciences, King's College London
- Upper Gastrointestinal Surgery, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - D. Landau
- Department of Oncology, Guy's and St Thomas' Hospital, London, UK
| | - V. Goh
- School of Biomedical Engineering and Imaging Sciences, King's College London
- Cancer Epidemiology and Population Health Associated Research Group, King's College London
| | - A. R. Davies
- Department of Surgery, Guy's and St Thomas' Oesophago‐Gastric Centre, King's College London
- School of Cancer and Pharmaceutical Sciences, King's College London
- Upper Gastrointestinal Surgery, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
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Chia B, Nei W, Fong K, Yap S, Chua K, Yip C, Ng W, Siow T, Tan M. EP1.18-17 Pre-Radical Radiotherapy Plasma EGFR DNA Levels in Lung Cancer Patients May Predict for Early Disease Progression. J Thorac Oncol 2019. [DOI: 10.1016/j.jtho.2019.08.2462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Yip C, Goia C, Botly L, Hill M, Casaubon L, Mulvagh S, Martin-Rhee M, Lindsay M. UNDERSTANDING RELATIONSHIPS IN TEMPORAL TRENDS OF HOSPITALIZATIONS FOR CARDIOVASCULAR DISEASES, STROKE AND VASCULAR COGNITIVE IMPAIRMENT FROM 2007 TO 2017. Can J Cardiol 2019. [DOI: 10.1016/j.cjca.2019.07.446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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20
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Yip C, Tan S, Chua K, Siow T, Thiagarajan A, Fong K, Yap S, Ng W, Chia B, Tan J. P1.18-10 The Prognostic Impact of the Extent of Nodal Involvement in NSCLC Treated with Radical Chemoradiation. J Thorac Oncol 2019. [DOI: 10.1016/j.jtho.2019.08.1326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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21
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Owczarczyk K, Kelly-Morland C, Yip C, Siddique M, Maisey N, Qureshi A, Gossage J, Cook G, Goh V. EP-1425 MRI heterogeneity analysis for predicting response to neoadjuvant therapy in oesophageal cancer. Radiother Oncol 2019. [DOI: 10.1016/s0167-8140(19)31845-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Sammons S, Yip C, Anderson G, Force J, Marcom K, Westbrook K, Anders CK, Blackwell K, Wood K. Abstract P1-06-04: Small-molecule screening nominates diverse combination therapies that sensitize BRCA mutant and wild-type triple negative breast cancer to PARP inhibition. Cancer Res 2019. [DOI: 10.1158/1538-7445.sabcs18-p1-06-04] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: Triple negative breast cancer (TNBC) remains a heterogeneous clinical phenotype with few, known therapeutic targets. PARP inhibitors (PARPi) are the first approved, targeted therapy in TNBC, limited to germline BRCA mutant (BRCAm) cancers that lack homologous recombination repair capacity. Even in this context, resistance quickly emerges via secondary mutations that restore DNA repair ability. While DNA damage repair is an intriguing target in BRCA wild type (BRCAwt) TNBC due to inherent, genomic instability, PARPi alone have been ineffective in unselected populations. Systematic approaches to define novel drugs that sensitize BRCAwt and BRCAm TNBC to PARPi would greatly improve therapeutic efficacy and durability.
Methods: BRCAwt (HCC1806) and BRCAm (SUM149PT) cell lines were screened in duplicate using a 2,100-compound small molecule library. Cell lines were plated in media containing DMSO or sub-lethal doses of the PARPi, olaparib, onto Selleck Bioactive drug plates. Cell viability was assessed after 72 hours, then normalized to vehicle control. Hit cut-offs were predefined as log2 drug/DMSO of ≤ -0.7 with a viability difference greater than 20% -where stringent scoring thresholds were chosen to exceed the full range of scores observed in 816 empty control wells. Hits were sorted by target and pathway to provide mechanistic insight into the synergy of combinations. Drug combinations with the highest potential for near term translation were validated using GI50 viability assays in 9 BRCAwt and BRCAm TNBC cell lines. The most promising combination was further validated via immunoblotting, colony formation, and apoptosis assays.
Results: Several drug classes affecting well-known oncogenic signaling pathways conferred sensitivity to PARPi, with more hits in the BRCAm cell line. Relevant druggable targets sensitizing cells to olaparib in BRCAm TNBC that met the predefined cut-point were inhibitors of PI3K (pan-PI3K, PI3Kα and PI3Kβ specific), VEGFR, MEK, EGFR, NF-kB, aurora kinase and several DNA damaging agents. Aurora kinase, EGFR, and NF-kB inhibition sensitized cells to olaparib, yet upon further validation, synergy was mild. The screen identified ATM inhibitors, KU-55933 and KU-60019, as sensitizers of BRCAm cells to olaparib. The potent ATM inhibitor, AZD0156, and olaparib were a highly synergistic combination validated in all 9 BRCAm and BRCAwt TNBC cell lines via cell viability, annexin V, and colony formation assays. Immunoblotting of relevant DNA damage repair proteins showed that olaparib caused upregulation of p-ATM in BRCAm and BRCAwt cells. p-ATM expression decreased in response to combination ATM and PARP inhibition. Attenuated levels of p-ATM resulted in increased levels of p- and T-γH2AX, indicating an accumulation of double stranded DNA breaks.
Conclusion: In vitro, inhibition of several relevant, oncogenic pathways yielded sensitivity to PARPi in TNBC. We identified the ATM inhibitor, AZD0156, and olaparib as a potent combination regardless of BRCA status, a finding currently being evaluated in patient-derived in vivo models. Combination ATM plus PARP inhibitor therapy is a promising and feasible approach for near term translation in metastatic TNBC.
Citation Format: Sammons S, Yip C, Anderson G, Force J, Marcom K, Westbrook K, Anders CK, Blackwell K, Wood K. Small-molecule screening nominates diverse combination therapies that sensitize BRCA mutant and wild-type triple negative breast cancer to PARP inhibition [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-06-04.
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Affiliation(s)
- S Sammons
- Duke University Hospital/ Duke Cancer Institute, Durham, NC; University of North Carolina, Chapel Hill, NC
| | - C Yip
- Duke University Hospital/ Duke Cancer Institute, Durham, NC; University of North Carolina, Chapel Hill, NC
| | - G Anderson
- Duke University Hospital/ Duke Cancer Institute, Durham, NC; University of North Carolina, Chapel Hill, NC
| | - J Force
- Duke University Hospital/ Duke Cancer Institute, Durham, NC; University of North Carolina, Chapel Hill, NC
| | - K Marcom
- Duke University Hospital/ Duke Cancer Institute, Durham, NC; University of North Carolina, Chapel Hill, NC
| | - K Westbrook
- Duke University Hospital/ Duke Cancer Institute, Durham, NC; University of North Carolina, Chapel Hill, NC
| | - CK Anders
- Duke University Hospital/ Duke Cancer Institute, Durham, NC; University of North Carolina, Chapel Hill, NC
| | - K Blackwell
- Duke University Hospital/ Duke Cancer Institute, Durham, NC; University of North Carolina, Chapel Hill, NC
| | - K Wood
- Duke University Hospital/ Duke Cancer Institute, Durham, NC; University of North Carolina, Chapel Hill, NC
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Yip C, Wang M, Siow T, Lim F, Tan D, Chin F, Chua E, Wang F, Ho S, Khin N. Prognostic Impact of Systemic Inflammatory Markers in Esophageal Squamous Cell Carcinoma treated with Chemoradiation. Int J Radiat Oncol Biol Phys 2018. [DOI: 10.1016/j.ijrobp.2018.07.453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Sin I, Chia B, Yip C, Ng W, Siow T, Thiagarajan A, Yap S, Fong K, Chua K. Stereotactic Ablative Radiation Therapy Achieves Excellent Outcomes for Elderly Patients with Bulky Early-Stage Non-Small-Cell Lung Cancer. Int J Radiat Oncol Biol Phys 2018. [DOI: 10.1016/j.ijrobp.2018.07.1898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Lee C, Chua G, Zheng H, Soon Y, Foo L, Thiagarajan A, Yap S, Siow T, Ng W, Chua K, Yip C, Chia B, Ng Y, Master Z, Tan P, Tan Y, Leong Y, Loria J, Vellayappan B, Koh W, Leong C, Tey J, Tham I, Fong K. P2.01-63 Are Heart Doses Associated with Survival in NSCLC Treated with Post-Operative Radiotherapy? A National Population-Based Study. J Thorac Oncol 2018. [DOI: 10.1016/j.jtho.2018.08.1117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Chia B, Ng W, Yap S, Chua K, Yip C, Thiagarajan A, Siow T, Fong K. P3.08-07 An Institution Review of Outcomes of Lung Stereotactic Body Radiotherapy in Various Oligometastatic Disease States. J Thorac Oncol 2018. [DOI: 10.1016/j.jtho.2018.08.1757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Sharma SK, Yip C, Esposito EX, Sharma PV, Simon MP, Abel-Santos E, Firestine SM. The Design, Synthesis, and Characterizations of Spore Germination Inhibitors Effective against an Epidemic Strain of Clostridium difficile. J Med Chem 2018; 61:6759-6778. [PMID: 30004695 DOI: 10.1021/acs.jmedchem.8b00632] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Clostridium difficile infections (CDI), particularly those caused by the BI/NAP1/027 epidemic strains, are challenging to treat. One method to address this disease is to prevent the development of CDI by inhibiting the germination of C. difficile spores. Previous studies have identified cholic amide m-sulfonic acid, CamSA, as an inhibitor of spore germination. However, CamSA is inactive against the hypervirulent strain R20291. To circumvent this problem, a series of cholic acid amides were synthesized and tested against R20291. The best compound in the series was the simple phenyl amide analogue which possessed an IC50 value of 1.8 μM, more than 225 times as potent as the natural germination inhibitor, chenodeoxycholate. This is the most potent inhibitor of C. difficile spore germination described to date. QSAR and molecular modeling analysis demonstrated that increases in hydrophobicity and decreases in partial charge or polar surface area were correlated with increases in potency.
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Affiliation(s)
- Shiv K Sharma
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences , Wayne State University , 259 Mack Avenue , Detroit , Michigan 48201 , United States
| | - Christopher Yip
- Department of Chemistry and Biochemistry , University of Nevada at Las Vegas , 4505 South Maryland Parkway , Las Vegas , Nevada 89154 , United States
| | | | - Prateek V Sharma
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences , Wayne State University , 259 Mack Avenue , Detroit , Michigan 48201 , United States
| | - Matthew P Simon
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences , Wayne State University , 259 Mack Avenue , Detroit , Michigan 48201 , United States
| | - Ernesto Abel-Santos
- Department of Chemistry and Biochemistry , University of Nevada at Las Vegas , 4505 South Maryland Parkway , Las Vegas , Nevada 89154 , United States
| | - Steven M Firestine
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences , Wayne State University , 259 Mack Avenue , Detroit , Michigan 48201 , United States
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Santoni N, Yip C, Chew B. Can we still deliver a safe day case plastic surgery service at a modern ambulatory care hospital (ACH) after seven years? A re-audit of a single surgeon’s series. Int J Surg 2018. [DOI: 10.1016/j.ijsu.2018.05.461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Khin N, Peh W, Tham W, Lam W, Wang M, Siow T, Lim F, Tan D, Chin F, Chua E, Wang F, Ho S, Yip C. Biochemical and radiological inflammatory markers in oesophageal squamous cell carcinoma treated with radical chemoradiation. Ann Oncol 2018. [DOI: 10.1093/annonc/mdy151.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Foidart P, Yip C, Radermacher J, Collignon J, Coibion M, Blacher S, Marangoni E, Sounni N, Noël A, Jerusalem G. PO-524 MT4-MMP, EGFR and Rb expressions are predictive biomarkers of response to erlotinib-palbociclib combination in TNBC. ESMO Open 2018. [DOI: 10.1136/esmoopen-2018-eacr25.1025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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31
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Lindsay M, Goia C, Yip C. Strategic Framework for Monitoring the Quality of Heart and Brain Care in Canada. Can J Cardiol 2018. [DOI: 10.1016/j.cjca.2018.01.066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Le Dévédec F, Her S, Vogtt K, Won A, Li X, Beaucage G, Yip C, Allen C. Drug governs the morphology of polyalkylated block copolymer aggregates. Nanoscale 2017; 9:2417-2423. [PMID: 27935620 DOI: 10.1039/c6nr08215g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Polyalkylated copolymers based on mPEG-b-(AGE-C6,12 or 18)25 have been used to formulate clinically relevant concentrations of doxorubicin (DOX) and the impact of drug incorporation on copolymer aggregation behaviour was examined. The copolymer aggregates were analyzed by various microscopy techniques (TEM, cryo-TEM and AFM) and scattering methods (SANS, DLS). In the absence of the drug, the copolymers formed largely non-spherical aggregates (i.e. cylinders, vesicles). Drug incorporation during copolymer aggregate formation directed the formation of only spherical aggregates. As well, the nature of the core-forming block was found to influence drug release and cytotoxicity of the formulations.
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Affiliation(s)
- F Le Dévédec
- Leslie Dan Faculty of Pharmacy, Department of Pharmaceutical Sciences, University of Toronto, Canada.
| | - S Her
- Leslie Dan Faculty of Pharmacy, Department of Pharmaceutical Sciences, University of Toronto, Canada.
| | - K Vogtt
- CEAS-Biomedical, Chemical, and Environmental Engineering, University of Cincinnati, USA
| | - A Won
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Canada
| | - X Li
- Leslie Dan Faculty of Pharmacy, Department of Pharmaceutical Sciences, University of Toronto, Canada.
| | - G Beaucage
- CEAS-Biomedical, Chemical, and Environmental Engineering, University of Cincinnati, USA
| | - C Yip
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Canada
| | - C Allen
- Leslie Dan Faculty of Pharmacy, Department of Pharmaceutical Sciences, University of Toronto, Canada. and Institute of Biomaterials and Biomedical Engineering, University of Toronto, Canada
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Yeo W, Mo F, Suen J, Loong H, Pang E, Yip C, Liem G. Dyslipidaemias after adjuvant chemotherapy in young Chinese breast cancer patients. Ann Oncol 2016. [DOI: 10.1093/annonc/mdw364.57] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Yip C. Review Section: The Production of Knowledge: The Challenge of Social Science Research WILLIAM H. STARBUCK. New York: Oxford University Press Inc., 2006. 194 pp. ISBN 0199288534. Management Learning 2016. [DOI: 10.1177/13505076070380030804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Christopher Yip
- Department of Management and Marketing, The University of Melbourne, Australia
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Yip C, Weeks A, Cook G, Landau D, Goh V. PO-0989: Hypoxic and perfusion effects of Trastuzumab in a HER2+ oesophageal adenocarcinoma xenograft model. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)32239-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Chang A, Cheung F, Wong T, Wong E, Cho F, Yip C, Soong I, Law A, Lee M, Yeung R. PO-0963: Effectiveness of week 5 MRI virtual preplanning for Image-Guided Brachytherapy for cervical cancers. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)32213-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Yip C, Ignjatovic V, Attard C, Karlaftis V, Linden M, Monagle P, Jimenez-Fonseca P. Removal notice to “Characterisation of the Age-Specific Differences in Platelet Physiology and Function” [Thromb. Res. 133 (2014) S91]. Thromb Res 2015. [DOI: 10.1016/j.thromres.2015.09.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Mahajan A, Cook G, Goh V, Yip C, Siddique MM. Effects of body composition as measured by CT on clinical outcomes in patients with oesophageal cancer. Cancer Imaging 2015. [PMCID: PMC4601823 DOI: 10.1186/1470-7330-15-s1-p25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Jennings W, Doshi S, Won A, Yip C, Epand R. Mammalian Diacylglycerol Kinase Epsilon: Expression in Sf21 Cells, Purification, and Characterization. FASEB J 2015. [DOI: 10.1096/fasebj.29.1_supplement.895.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Amy Won
- BiochemistryUniversity of TorontoCanada
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Yip C, Davnall F, Kozarski R, Landau DB, Cook GJR, Ross P, Mason R, Goh V. Assessment of changes in tumor heterogeneity following neoadjuvant chemotherapy in primary esophageal cancer. Dis Esophagus 2015; 28:172-9. [PMID: 24460831 DOI: 10.1111/dote.12170] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
To assess the changes in computed tomography (CT) tumor heterogeneity following neoadjuvant chemotherapy in esophageal cancer. Thirty-one consecutive patients who received neoadjuvant chemotherapy for esophageal cancer were identified. Analysis of primary tumor heterogeneity (texture) was performed on staging and post-chemotherapy CT scans. Image texture parameters (mean grey-level intensity, entropy, uniformity, kurtosis, skewness, standard deviation of histogram) were derived for different levels of image filtration (0-2.5). Proportional changes in each parameter following treatment were obtained. Comparison between pathological tumor response and texture parameters was analyzed using Mann-Whitney U-test. The relationship between CT texture and overall survival) was estimated using the Kaplan-Meier method. Tumor texture became more homogeneous after treatment with a significant decrease in entropy and increase in uniformity (filter 1.0 and 2.5). Pretreatment (filter 1.5, P = 0.006) and posttreatment standard deviation of histogram (filter 1.0, P = 0.009) showed a borderline association with pathological tumor response. A proportional change in skewness <0.39 (filter 1.0) was associated with improved survival (median overall survival 36.1 vs. 11.1 months; P < 0.001). CT tumor heterogeneity decreased following neoadjuvant chemotherapy and has the potential to provide additional information in primary esophageal cancer.
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Affiliation(s)
- C Yip
- Division of Imaging Sciences & Biomedical Engineering, King's College London, London, UK; Department of Radiation Oncology, National Cancer Centre, Singapore
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Yip C, Cook GJR, Landau DB, Davies A, Goh V. Performance of different imaging modalities in assessment of response to neoadjuvant therapy in primary esophageal cancer. Dis Esophagus 2015; 29:116-30. [PMID: 25604614 DOI: 10.1111/dote.12315] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- C Yip
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK.,Department of Radiation Oncology, National Cancer Center, Singapore
| | - G J R Cook
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK
| | - D B Landau
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK.,Department of Clinical Oncology, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - A Davies
- Department of General Surgery, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - V Goh
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK.,Department of Radiology, Guy's and St Thomas' NHS Foundation Trust, London, UK
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Yip C, Chew BK. A simple technique for reinflating a Becker expander when tube breakage occurs during port removal. J Plast Reconstr Aesthet Surg 2014; 67:1599-600. [PMID: 24934097 DOI: 10.1016/j.bjps.2014.05.050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 05/20/2014] [Indexed: 11/30/2022]
Affiliation(s)
- C Yip
- Canniesburn Plastic Surgery Unit, Glasgow Royal Infirmary, 84 Castle Street, G4 0SF, United Kingdom.
| | - B K Chew
- Canniesburn Plastic Surgery Unit, Glasgow Royal Infirmary, 84 Castle Street, G4 0SF, United Kingdom
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Yip C, Ignjatovic V, Attard C, Karlaftis V, Linden M, Monagle P, Jimenez-Fonseca P. REMOVED: Characterisation of the Age-Specific Differences in Platelet Physiology and Function. Thromb Res 2014. [DOI: 10.1016/s0049-3848(14)50293-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Heedy S, Lo M, Dillon E, Hu Q, Prater C, Shetty R, Kjoller K, Marcott C, Dazzi A, Yip C. Chemical Analysis Below the Diffraction Limit using Infrared-Coupled Atomic Force Microscopy (AFM-IR). Biophys J 2014. [DOI: 10.1016/j.bpj.2013.11.1203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Yip C, Thomas C, Michaelidou A, James D, Lynn R, Lei M, Guerrero Urbano T. Co-registration of cone beam CT and planning CT in head and neck IMRT dose estimation: a feasible adaptive radiotherapy strategy. Br J Radiol 2013; 87:20130532. [PMID: 24288402 DOI: 10.1259/bjr.20130532] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To investigate if cone beam CT (CBCT) can be used to estimate the delivered dose in head and neck intensity-modulated radiotherapy (IMRT). METHODS 15 patients (10 without replan and 5 with replan) were identified retrospectively. Weekly CBCT was co-registered with original planning CT. Original high-dose clinical target volume (CTV1), low-dose CTV (CTV2), brainstem, spinal cord, parotids and external body contours were copied to each CBCT and modified to account for anatomical changes. Corresponding planning target volumes (PTVs) and planning organ-at-risk volumes were created. The original plan was applied and calculated using modified per-treatment volumes on the original CT. Percentage volumetric, cumulative (planned dose delivered prior to CBCT + adaptive dose delivered after CBCT) and actual delivered (summation of weekly adaptive doses) dosimetric differences between each per-treatment and original plan were calculated. RESULTS There was greater volumetric change in the parotids with an average weekly difference of between -4.1% and -27.0% compared with the CTVs/PTVs (-1.8% to -5.0%). The average weekly cumulative dosimetric differences were as follows: CTV/PTV (range, -3.0% to 2.2%), ipsilateral parotid volume receiving ≥26 Gy (V26) (range, 0.5-3.2%) and contralateral V26 (range, 1.9-6.3%). In patients who required replan, the average volumetric reductions were greater: CTV1 (-2.5%), CTV2 (-6.9%), PTV1 (-4.7%), PTV2 (-11.5%), ipsilateral (-10.4%) and contralateral parotids (-12.1%), but did not result in significant dosimetric changes. CONCLUSION The dosimetric changes during head and neck simultaneous integrated boost IMRT do not necessitate adaptive radiotherapy in most patients. ADVANCES IN KNOWLEDGE Our study shows that CBCT could be used for dose estimation during head and neck IMRT.
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Affiliation(s)
- C Yip
- Department of Oncology, St Thomas' Hospital, Guy's and St Thomas' NHS Foundation Trust, London, UK
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Yip C, Landau D, Thomas C, Ahmad S. 171 Stereotactic ablative radiotherapy (SABR) in medically inoperable early stage non-small cell lung cancer (NSCLC): A single tertiary UK centre experience. Lung Cancer 2013. [DOI: 10.1016/s0169-5002(13)70171-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Yip C, Michaelidou A, Thomas R, Goh V, Landau D. CT Prognostication in Esophageal Cancer Treated With Definitive Chemoradiation Is Still Relevant. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Yip C, Landau D, Ahmad S, Goh V, Siddique M, Chicklore S, Roy A, Cook G. Pretreatment FDG PET Tumor Heterogeneity in Non-small Cell Lung Cancer is Associated With Poor Response and Survival Following Chemoradiation Therapy. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.1474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Yip C, Liu D, Lobie PE, Perry JK. P4-02-05: The Regulation of Artemin Signalling by IGF-1 in Mammary Carcinoma Cells. Cancer Res 2011. [DOI: 10.1158/0008-5472.sabcs11-p4-02-05] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Artemin is a neurotrophic signalling factor which belongs to the glial-derived neurotrophic factor (GDNF) family of ligands. Artemin acts as a survival, proliferation and migration factor for a number of neurological cell types, by signalling through the RET (rearranged during transfection) receptor and, in most cases, the GDNF receptor (GFR)-a3 co-receptor. Recently, a number of published studies have implicated Artemin as a potential oncogene in several cell types, including mammary carcinoma cells. Other studies further indicate that Artemin may influence cancer progression and tamoxifen resistance in some breast cancers. Available clinical data has demonstrated that increased Artemin expression is correlated with decreased overall patient survival in breast cancer patients and a poor outcome in tamoxifen treated breast cancer patients. Here we investigate interaction between the Artemin and the insulin-like growth factor-1 (IGF-1) signal transduction pathways. Using mammary carcinoma cell lines, we demonstrate that IGF-1 treatment increases the endogenous expression of both Artemin and its endogenous receptors, RET and GFRa3. Semi-quantitative RT-PCR assays demonstrated that IGF-1 stimulated mRNA expression of Artemin as well as RET and GFRa3 in wild-type MCF-7 and ZR-75-1 cells in a time-dependent and dose-dependent manner. The same effect was not observed in wild-type T47D cells where IGF-1 did not increase Artemin mRNA expression.
We also demonstrated that forced expression of Artemin in MCF-7 cells consistently enhanced the response of these cells to IGF-1 in a number of cell function assays. Forced expression of Artemin significantly enhanced IGF-1-mediated stimulation of total cell number in MCF-7 cells. Consistent with this, Artemin enhanced IGF-1-mediated stimulation of S-phase entry and cell survival. In a soft agar assay, forced expression of Artemin also enhanced IGF-1-mediated stimulation of colony formation. Conversely, depletion of Artemin expression using siRNA abrogated the response to IGF-1 stimulation in MCF-7 cells. Artemin depletion significantly decreased IGF-1-stimulated increase in total cell number by decreasing IGF-1-stimulated cell proliferation and protection from apoptotic cell death. In addition, forced expression of Artemin in MCF-7 cells reduced cell sensitivity to the IGF-1 receptor small molecule inhibitor, AG1024. In conclusion, we have demonstrated that IGF-1 increases Artemin mRNA and protein expression in the breast cancer cell lines MCF-7 and ZR-75-1 and have identified potential cross-talk between the Artemin and IGF-1 signalling pathways in MCF-7 cells.
Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-02-05.
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Affiliation(s)
- C Yip
- 1University of Auckland, Auckland, New Zealand; National University of Singapore, Singapore
| | - D Liu
- 1University of Auckland, Auckland, New Zealand; National University of Singapore, Singapore
| | - PE Lobie
- 1University of Auckland, Auckland, New Zealand; National University of Singapore, Singapore
| | - JK Perry
- 1University of Auckland, Auckland, New Zealand; National University of Singapore, Singapore
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Yip C, Cheng H, Cheung F, Chan C. SU-E-T-89: Comparison of a Liquid Ionization Chamber with a Diamond Detector for Relatively Small Photon Field Measurements. Med Phys 2011. [DOI: 10.1118/1.3612040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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