36 results on '"Ryan Robb"'
Search Results
2. A novel protein-drug conjugate, SSH20, demonstrates significant efficacy in caveolin-1-expressing tumors
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Ryan Robb, Jimmy Chun-Tien Kuo, Yang Liu, Sergio Corrales-Guerrero, Tiantian Cui, Ahmad Hegazi, Gregory Nagy, Robert J. Lee, and Terence M. Williams
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SSH20 ,lung cancer ,pancreatic cancer ,caveolin-1 ,albumin ,SN-38 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
In recent years, human serum albumin (HSA) has been characterized as an ideal drug carrier in the cancer arena. Caveolin-1 (Cav-1) has been established as the principal structural protein of caveolae and, thus, critical for caveolae-mediated endocytosis. Cav-1 has been shown to be overexpressed in cancers of the lung and pancreas, among others. We found that Cav-1 expression plays a critical role in both HSA uptake and response to albumin-based chemotherapies. As such, developing a novel albumin-based chemotherapy that is more selective for tumors with high Cav-1 expression or high levels of caveolar-endocytosis could have significant implications in biomarker-directed therapy. Herein, we present the development of a novel and effective HSA-SN-38 conjugate (SSH20). We find that SSH20 uptake decreases significantly by immunofluorescence assays and western blotting after silencing of Cav-1 expression through RNA interference. Decreased drug sensitivity occurs in Cav-1-depleted cells using cytotoxicity assays. Importantly, we find significantly reduced sensitivity to SSH20 in Cav-1-silenced tumors compared to Cav-1-expressing tumors in vivo. Notably, we show that SSH20 is significantly more potent than irinotecan in vitro and in vivo. Together, we have developed a novel HSA-conjugated chemotherapy that is potent, effective, safe, and demonstrates improved efficacy in high Cav-1-expressing tumors.
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- 2021
- Full Text
- View/download PDF
3. Development of a MicroRNA Signature Predictive of Recurrence and Survival in Pancreatic Ductal Adenocarcinoma
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Nikhil T. Sebastian, Amy Webb, Kenneth W. Merrell, Eugene J. Koay, Adam R. Wolfe, Lizhi Zhang, Tyler J. Wilhite, Dalia Elganainy, Ryan Robb, Wei Chen, Jordan Cloyd, Mary Dillhoff, Allan Tsung, Laith Abushahin, Anne Noonan, and Terence M. Williams
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pancreatic cancer ,microRNA ,locoregional recurrence ,local recurrence ,adjuvant radiation ,neoadjuvant radiation ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Background: Optimal patient selection for radiotherapy in pancreatic ductal adenocarcinoma (PDAC) is unestablished. Molecular profiling may select patients at high risk for locoregional recurrence (LRR) who would benefit from radiation. Methods: We included resectable pancreatic cancer (R-PDAC) patients, divided into training and validation cohorts, treated among three institutions with surgery and adjuvant chemotherapy, and borderline resectable or locally advanced pancreatic cancer (BR/LA-PDAC) patients treated with chemotherapy with or without radiation at the primary study institution. We isolated RNA from R-PDAC surgical specimens. Using NanoString, we identified miRNAs differentially expressed between normal and malignant pancreatic tissue. ElasticNet regression identified two miRNAs most predictive of LRR in the training cohort, miR-181b/d and miR-575, which were used to generate a risk score (RS). We evaluated the association of the median-dichotomized RS with recurrence and overall survival (OS). Results: We identified 183 R-PDAC and 77 BR/LA-PDAC patients with median follow up of 37 months treated between 2001 and 2014. On multivariable analysis of the R-PDAC training cohort (n = 90), RS was associated with worse LRR (HR = 1.34; 95%CI 1.27–11.38; p = 0.017) and OS (HR = 2.89; 95%CI 1.10–4.76; p = 0.027). In the R-PDAC validation cohort, RS was associated with worse LRR (HR = 2.39; 95%CI 1.03–5.54; p = 0.042), but not OS (p = 0.087). For BR/LA-PDAC, RS was associated with worse LRR (HR = 2.71; 95%CI 1.14–6.48; p = 0.025), DR (HR = 1.93; 95%CI 1.10–3.38; p = 0.022), and OS (HR = 1.97; 95%CI 1.17–3.34; p = 0.011). Additionally, after stratifying by RS and receipt of radiation in BR/LA-PDAC patients, high RS patients who did not receive radiation had worse LRR (p = 0.018), DR (p = 0.006), and OS (p < 0.001) compared to patients with either low RS or patients who received radiation, irrespective of RS. Conclusions: RS predicted worse LRR and OS in R-PDAC and worse LRR, DR, and OS in BR/LA-PDAC. This may select patients who would benefit from radiation and should be validated prospectively.
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- 2021
- Full Text
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4. Supplementary Figures from Altered Gemcitabine and Nab-paclitaxel Scheduling Improves Therapeutic Efficacy Compared with Standard Concurrent Treatment in Preclinical Models of Pancreatic Cancer
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Terence M. Williams, Arnab Chakravarti, Kamalakannan Palanichamy, John R. Jacob, Zobeida Cruz-Monserrate, Jose G. Trevino, Duan-Liang Shyu, Linlin Yang, Laith Abushahin, Ahmad Hegazi, Ryan Robb, and Adam R. Wolfe
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Supplementary Figures
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- 2023
5. Supplementary fig 3 from Phase I Trial of Trametinib with Neoadjuvant Chemoradiation in Patients with Locally Advanced Rectal Cancer
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Evan Wuthrick, Tanios Bekaii-Saab, Sameek Roychowdhury, Sherif Abdel-Misih, Alan Harzman, Mark Arnold, Somashekar G. Krishna, Cynthia Timmers, Dana B. Cardin, Kristen K. Ciombor, Sameh Mikhail, Wei Chen, Lai Wei, Amy Webb, Ryan Robb, Terence M. Williams, and Christina Wu
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Supplementary fig 3 Tumor Regression Grade versus Baseline p-ERK score in Tumor Tissue
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- 2023
6. Supplementary fig 1 from Phase I Trial of Trametinib with Neoadjuvant Chemoradiation in Patients with Locally Advanced Rectal Cancer
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Evan Wuthrick, Tanios Bekaii-Saab, Sameek Roychowdhury, Sherif Abdel-Misih, Alan Harzman, Mark Arnold, Somashekar G. Krishna, Cynthia Timmers, Dana B. Cardin, Kristen K. Ciombor, Sameh Mikhail, Wei Chen, Lai Wei, Amy Webb, Ryan Robb, Terence M. Williams, and Christina Wu
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Supplementary fig 1 Flowchart for trial design
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- 2023
7. Data from Altered Gemcitabine and Nab-paclitaxel Scheduling Improves Therapeutic Efficacy Compared with Standard Concurrent Treatment in Preclinical Models of Pancreatic Cancer
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Terence M. Williams, Arnab Chakravarti, Kamalakannan Palanichamy, John R. Jacob, Zobeida Cruz-Monserrate, Jose G. Trevino, Duan-Liang Shyu, Linlin Yang, Laith Abushahin, Ahmad Hegazi, Ryan Robb, and Adam R. Wolfe
- Abstract
Purpose:Concurrent gemcitabine and nab-paclitaxel treatment is one of the preferred chemotherapy regimens for metastatic and locally advanced pancreatic ductal adenocarcinoma (PDAC). Previous studies demonstrate that caveolin-1 (Cav-1) expression is critical for nab-paclitaxel uptake into tumors and correlates with response. Gemcitabine increases nab-paclitaxel uptake by increasing Cav-1 expression. Thus, we hypothesized that pretreatment with gemcitabine would further enhance the sensitivity of PDAC to nab-paclitaxel by increasing Cav-1 expression and nab-paclitaxel uptake.Experimental Design:We investigated the sensitivity of different gemcitabine and nab-paclitaxel treatment regimens in a panel of PDAC cell lines and orthotopic xenograft models. The sensitivity of different treatment regimens was compared with the standard concurrent treatment.Results:Pretreatment with gemcitabine before nab-paclitaxel increased Cav-1 and albumin uptake and significantly decreased proliferation and clonogenicity compared with concurrent treatment, which correlated with increased levels of apoptosis. Cav-1 silencing reduced the uptake of albumin, and therapeutic advantage was observed when cells were pretreated with gemcitabine prior to nab-paclitaxel. In addition, we observed that pretreatment with gemcitabine resulted in partial synchronization of cells in the G2–M-phase at the time of nab-paclitaxel treatment, providing another mechanism for the benefit of altered scheduling. In heterotopic and orthotopic xenograft models, the altered schedule of gemcitabine prior to nab-paclitaxel significantly delayed tumor growth compared with concurrent delivery without added toxicity.Conclusions:Pretreatment with gemcitabine significantly increased nab-paclitaxel uptake and correlated with an increased treatment efficacy and survival benefit in preclinical models, compared with standard concurrent treatment. These results justify preclinical and clinical testing of this altered scheduling combination.
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- 2023
8. Supplementary fig 2 from Phase I Trial of Trametinib with Neoadjuvant Chemoradiation in Patients with Locally Advanced Rectal Cancer
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Evan Wuthrick, Tanios Bekaii-Saab, Sameek Roychowdhury, Sherif Abdel-Misih, Alan Harzman, Mark Arnold, Somashekar G. Krishna, Cynthia Timmers, Dana B. Cardin, Kristen K. Ciombor, Sameh Mikhail, Wei Chen, Lai Wei, Amy Webb, Ryan Robb, Terence M. Williams, and Christina Wu
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Supplementary fig 2 Schema for trial design
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- 2023
9. Supplementary Data from Phase I Trial of Trametinib with Neoadjuvant Chemoradiation in Patients with Locally Advanced Rectal Cancer
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Evan Wuthrick, Tanios Bekaii-Saab, Sameek Roychowdhury, Sherif Abdel-Misih, Alan Harzman, Mark Arnold, Somashekar G. Krishna, Cynthia Timmers, Dana B. Cardin, Kristen K. Ciombor, Sameh Mikhail, Wei Chen, Lai Wei, Amy Webb, Ryan Robb, Terence M. Williams, and Christina Wu
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Table showing next generation sequencing of tumor samples
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- 2023
10. Supplementary fig 5 from Phase I Trial of Trametinib with Neoadjuvant Chemoradiation in Patients with Locally Advanced Rectal Cancer
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Evan Wuthrick, Tanios Bekaii-Saab, Sameek Roychowdhury, Sherif Abdel-Misih, Alan Harzman, Mark Arnold, Somashekar G. Krishna, Cynthia Timmers, Dana B. Cardin, Kristen K. Ciombor, Sameh Mikhail, Wei Chen, Lai Wei, Amy Webb, Ryan Robb, Terence M. Williams, and Christina Wu
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Supplementary fig 5 Degree of Reduction (%) in Tumor pERK Levels From Baseline to After Trametinib Monotherapy and Correlation With pCR
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- 2023
11. Data from Inhibiting BRAF Oncogene–Mediated Radioresistance Effectively Radiosensitizes BRAFV600E-Mutant Thyroid Cancer Cells by Constraining DNA Double-Strand Break Repair
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Terence M. Williams, Matthew D. Ringel, Sissy Jhiang, Motoyasu Saji, Marall Vedaie, Xiaoli Zhang, Amy Webb, Adam R. Wolfe, Changxian Shen, Linlin Yang, and Ryan Robb
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Purpose:Activating BRAF mutations, most commonly BRAFV600E, are a major oncogenic driver of many cancers. We explored whether BRAFV600E promotes radiation resistance and whether selectively targeting BRAFV600E with a BRAF inhibitor (vemurafenib, BRAFi) sensitizes BRAFV600E thyroid cancer cells to radiotherapy.Experimental Design:Immunoblotting, neutral comet, immunocytochemistry, functional reporter, and clonogenic assays were used to analyze the outcome and molecular characteristics following radiotherapy with or without BRAFV600E or vemurafenib in thyroid cancer cells.Results:BRAFV600E thyroid cancer cell lines were associated with resistance to ionizing radiation (IR), and expression of BRAFV600E into wild-type BRAF thyroid cancer cells led to IR resistance. BRAFi inhibited ERK signaling in BRAFV600E mutants, but not BRAF wild-type thyroid cancer cell lines. BRAFi selectively radiosensitized and delayed resolution of IR-induced γH2AX nuclear foci in BRAFV600E cells. Moreover, BRAFi impaired global DNA repair and altered the resolution of 53BP1 and RAD51 nuclear foci in BRAFV600E cells following IR. BRAFV600E mutants displayed enhanced nonhomologous end-joining (NHEJ) repair activity, which was abolished by BRAFi. Intriguingly, BRAFV600E mutation led to upregulation of XLF, a component of NHEJ, which was prevented by BRAFi. Importantly, BRAFi in combination with radiotherapy resulted in marked and sustained tumor regression of BRAFV600E thyroid tumor xenografts.Conclusions:BRAFV600E mutation promotes NHEJ activity leading to radioresistance and BRAFi selectively radiosensitizes BRAFV600E thyroid cancer cells through inhibiting NHEJ. Our findings suggest that combining BRAFi and radiation may improve the therapeutic outcome of patients with BRAFV600E-mutant thyroid cancer.
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- 2023
12. Supplementary fig 4 from Phase I Trial of Trametinib with Neoadjuvant Chemoradiation in Patients with Locally Advanced Rectal Cancer
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Evan Wuthrick, Tanios Bekaii-Saab, Sameek Roychowdhury, Sherif Abdel-Misih, Alan Harzman, Mark Arnold, Somashekar G. Krishna, Cynthia Timmers, Dana B. Cardin, Kristen K. Ciombor, Sameh Mikhail, Wei Chen, Lai Wei, Amy Webb, Ryan Robb, Terence M. Williams, and Christina Wu
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Supplementary fig 4 Baseline p-ERK score in Tumor Tissue Correlated to RAS/RAF Mutation Status
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- 2023
13. Supplementary Data from Inhibiting BRAF Oncogene–Mediated Radioresistance Effectively Radiosensitizes BRAFV600E-Mutant Thyroid Cancer Cells by Constraining DNA Double-Strand Break Repair
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Terence M. Williams, Matthew D. Ringel, Sissy Jhiang, Motoyasu Saji, Marall Vedaie, Xiaoli Zhang, Amy Webb, Adam R. Wolfe, Changxian Shen, Linlin Yang, and Ryan Robb
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Supplementary Table 1. Thyroid cancer cells lines used in this study Supplementary Figure 1. AlamarBlue® proliferation assay of TPC-1 stable cell lines. Supplemental Figure 2. Assessment of MEK-ERK activation in TPC-1 BRAFV600E stable cells. Supplementary Figure 3. Pooled radiation sensitivity data from melanoma, thyroid, colorectal cell lines either with BRAFV600E mutation or not. Supplementary Figure 4. Representative photos of plates from radiation clonogenic assays showing the effects of BRAFV600E inhibition with vemurafenib (Vem) resulting in radiosensitization in thyroid cancer cells harboring a BRAFV600E mutation (8505C, BCPAP) compared to vehicle (Ctrl) treated cells. Supplementary Figure 5. Plating efficiency of various thyroid cancer cell lines during radiation clonogenic assays in the presence of vemurafenib (Vem, 100nM) or vehicle (Ctrl). Supplementary Figure 6. BRAFV600E inhibition radiosensitizes melanoma cancer cells harboring a BRAFV600E mutation. Supplementary Figure 7. BRAFV600E inhibition does not alter the recovery of IR-induced DNA damage in BRAFWT thyroid cancer cells. Supplemental Figure 8. Assessment of BRAFV600E expression and MEK-ERK activation in 293T cells. Supplemental Table 2. mRNA expression ratio of NHEJ associated genes of thyroid cancer with BRAFV600E mutation compared to BRAF wild-type (BRAF wild-type: 203 cases; BRAFV600E mutant: 288 cases). Supplementary Figure 9. Expression of XLF is sufficient to induce radioresistance. Supplementary Figure 10. Treatment of BRAF inhibitor did not lead to significant weight loss of mice.
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- 2023
14. Data from Caveolae-Mediated Endocytosis Is Critical for Albumin Cellular Uptake and Response to Albumin-Bound Chemotherapy
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Terence M. Williams, Arnab Chakravarti, Matthew Harbrecht, Kamalakannan Palanichamy, Krishnan Thirumoorthy, Star Seum, Marall Vedaie, Ryan Robb, Edgar Ben-Josef, and Moumita Chatterjee
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Nab-paclitaxel, a nanoparticle conjugate of paclitaxel to human albumin, exhibits efficacy in pancreatic cancer, non–small cell lung cancer and breast cancer. However, there is a lack of predictive biomarkers to identify patients who might benefit most from its administration. This study addresses this gap in knowledge by identifying that caveolin-1 (Cav-1) is a candidate mechanism-based biomarker. Caveolae are small membrane invaginations important for transendothelial albumin uptake. Cav-1, the principal structural component of caveolae, is overexpressed in the cancers noted above that respond to nab-paclitaxel. Thus, we hypothesized that Cav-1 may be critical for albumin uptake in tumors and perhaps determine their response to this drug. Cav-1 protein levels correlated positively with nab-paclitaxel sensitivity. RNAi-mediated attenuation of Cav-1 expression reduced uptake of albumin and nab-paclitaxel in cancer cells and rendered them resistant to nab-paclitaxel–induced apoptosis. Conversely, Cav-1 overexpression enhanced sensitivity to nab-paclitaxel. Selection for cellular resistance to nab-paclitaxel in cell culture correlated with a loss of Cav-1 expression. In mouse xenograft models, cancer cells, where Cav-1 was attenuated, exhibited resistance to the antitumor effects of nab-paclitaxel therapy. Overall, our findings suggest Cav-1 as a predictive biomarker for the response to nab-paclitaxel and other albumin-based cancer therapeutic drugs. Cancer Res; 77(21); 5925–37. ©2017 AACR.
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- 2023
15. Figures S1-S5 from Caveolae-Mediated Endocytosis Is Critical for Albumin Cellular Uptake and Response to Albumin-Bound Chemotherapy
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Terence M. Williams, Arnab Chakravarti, Matthew Harbrecht, Kamalakannan Palanichamy, Krishnan Thirumoorthy, Star Seum, Marall Vedaie, Ryan Robb, Edgar Ben-Josef, and Moumita Chatterjee
- Abstract
Supplemental data that lists how standard curve for mass spectrometry was made (S1), individual nab-paclitaxel IC50 data (S2), electron microscopy images showing how Cav-1 depletion ablates caveolae (S3), additional cell line data showing response to paclitaxel or nab-paclitaxel (S4), and additional confocal microscopy images of low Cav-1 expressing cell lines (S5).
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- 2023
16. Data from Phase I Trial of Trametinib with Neoadjuvant Chemoradiation in Patients with Locally Advanced Rectal Cancer
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Evan Wuthrick, Tanios Bekaii-Saab, Sameek Roychowdhury, Sherif Abdel-Misih, Alan Harzman, Mark Arnold, Somashekar G. Krishna, Cynthia Timmers, Dana B. Cardin, Kristen K. Ciombor, Sameh Mikhail, Wei Chen, Lai Wei, Amy Webb, Ryan Robb, Terence M. Williams, and Christina Wu
- Abstract
Purpose:The RAS/RAF/MEK/ERK signaling pathway is critical to the development of colorectal cancers, and KRAS, NRAS, and BRAF mutations foster resistance to radiation. We performed a phase I trial to determine the safety of trametinib, a potent MEK1/2 inhibitor, with 5-fluorouracil (5-FU) chemoradiation therapy (CRT) in patients with locally advanced rectal cancer (LARC).Patients and Methods:Patients with stage II/III rectal cancer were enrolled on a phase I study with 3+3 study design, with an expansion cohort of 9 patients at the MTD. Following a 5-day trametinib lead-in, with pre- and posttreatment tumor biopsies, patients received trametinib and CRT, surgery, and adjuvant chemotherapy. Trametinib was given orally daily at 3 dose levels: 0.5 mg, 1 mg, and 2 mg. CRT consisted of infusional 5-FU 225 mg/m2/day and radiation dose of 28 daily fractions of 1.8 Gy (total 50.4 Gy). The primary endpoint was to identify the MTD and recommended phase II dose. IHC staining for phosphorylated ERK (pERK) and genomic profiling was performed on the tumor samples.Results:Patients were enrolled to all dose levels, and 18 patients were evaluable for toxicities and responses. Treatment was well tolerated, and there was one dose-limiting toxicity of diarrhea, which was attributed to CRT rather than trametinib. At the 2 mg dose level, 25% had pathologic complete response. IHC staining confirmed dose-dependent decrease in pERK with increasing trametinib doses.Conclusions:The combination of trametinib with 5-FU CRT is safe and well tolerated, and may warrant additional study in a phase II trial, perhaps in a RAS/RAF-mutant selected population.
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- 2023
17. Unraveling and targeting RAS-driven metabolic signaling for therapeutic gain
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Jonathan M, DeLiberty, Ryan, Robb, Claire E, Gates, and Kirsten L, Bryant
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Neoplasms ,Autophagy ,Humans ,Oncogenes ,Glycolysis ,Signal Transduction - Abstract
RAS mutations are among the most frequent oncogenic drivers observed in human cancers. With a lack of available treatment options, RAS-mutant cancers account for many of the deadliest cancers in the United States. Recent studies established that altered metabolic requirements are a hallmark of cancer, and many of these alterations are driven by aberrant RAS signaling. Specifically, RAS-driven cancers are characterized by upregulated glycolysis, the differential channeling of glycolytic intermediates, upregulated nutrient scavenging pathways such as autophagy and macropinocytosis, and altered glutamine utilization and mitochondrial function. This unique metabolic landscape promotes tumorigenesis, proliferation, survival in nutrient deficient environments and confers resistance to conventional cytotoxic and targeted therapies. Emerging work demonstrates how these dependencies can be therapeutically exploited in vitro and in vivo with many metabolic inhibitors currently in clinical trials. This review aims to outline the unique metabolic requirements induced by aberrant RAS signaling and how these altered dependencies present opportunities for therapeutic intervention.
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- 2022
18. Unraveling and targeting RAS-driven metabolic signaling for therapeutic gain
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Jonathan M. DeLiberty, Ryan Robb, Claire E. Gates, and Kirsten L. Bryant
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- 2022
19. A microRNA-based signature predicts local-regional failure and overall survival after pancreatic cancer resection
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Terence M. Williams, Ryan Robb, Mary Dillhoff, Wooil Kwon, Nikhil Sebastian, Adam R. Wolfe, Wendy L. Frankel, Wei Chen, Steve Walston, Patrick Wald, Jin-Young Jang, Amy Webb, and Marall Vedaie
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0301 basic medicine ,Oncology ,medicine.medical_specialty ,pancreatic cancer ,non-coding RNA ,Resection ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,Pancreatic cancer ,microRNA ,medicine ,Overall survival ,Prognostic biomarker ,prognostic biomarker ,local-regional recurrence ,miRNA ,Framingham Risk Score ,business.industry ,medicine.disease ,3. Good health ,030104 developmental biology ,030220 oncology & carcinogenesis ,Cohort ,Adenocarcinoma ,business ,Research Paper - Abstract
// Adam R. Wolfe 1 , * , Patrick Wald 1 , * , Amy Webb 1 , Nikhil Sebastian 1 , Steve Walston 1 , Ryan Robb 1 , Wei Chen 1 , Marall Vedaie 1 , Mary Dillhoff 1 , Wendy L. Frankel 1 , Wooil Kwon 2 , Jin-Young Jang 2 and Terence M. Williams 1 1 The Ohio State University Medical Center, Arthur G. James Comprehensive Cancer Center and Richard J. Solove Research Institute, Columbus, OH, USA 2 Department of Surgery, Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea * Co-first authors Correspondence to: Terence M. Williams, email: terence.williams@osumc.edu Keywords: pancreatic cancer; miRNA; non-coding RNA; prognostic biomarker; local-regional recurrence Received: November 12, 2019 Accepted: January 29, 2020 Published: March 10, 2020 ABSTRACT Resectable pancreatic adenocarcinoma (PC) is generally managed with surgery followed by chemotherapy, but the role of postoperative chemoradiation (pCRT) is controversial. We sought to identify a microRNA (miRNA) expression profile associated with higher risk for local-regional recurrence (LRR), which might help identify patients that may benefit from pCRT. Total RNA was isolated from viable tumor from 88 patients who underwent PC resection with or without chemotherapy, but did not receive radiation. Digital miRNA expression profiling was performed and risk scores were calculated based on the expression levels of the four most significantly correlated miRNAs, and dichotomized about the median to detect correlations between risk group, LRR and overall survival (OS). Two cohorts from The Cancer Genome Atlas (TCGA) and Seoul National University (SNU) were used for validation. Patients with high-risk scores had significantly worse LRR ( p = 0.001) and worse OS ( p = 0.034). Two-year OS rates for the high- and low-risk groups were 27.7% and 52.2%, respectively. On multivariable analysis, the risk score remained significantly associated with LRR ( p = 0.018). When validated on TCGA data, a high-risk score was associated with worse OS on univariate ( p = 0.03) and multivariable analysis ( p = 0.017). When validated on the SNU cohort, a high-risk score was likewise associated with worse OS ( p = 0.042). We have developed a 4-miRNA molecular signature that is associated with risk of LRR and OS after PC resection and validated on two separate cohorts. This signature has the potential to select patients most likely to benefit from pCRT, and should be tested further.
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- 2020
20. Abstract B007: Enhancing autophagy inhibition as a therapeutic strategy for pancreatic cancer
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Jonathan M. DeLiberty, Ryan Robb, Claire E. Gates, Noah L. Pieper, Runying Yang, Clint A. Stalnecker, and Kirsten L. Bryant
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Cancer Research ,Oncology - Abstract
Pancreatic ductal adenocarcinoma (PDAC) is characterized by KRAS- and autophagy-dependent tumorigenic growth. We determined the role of mutationally activated KRAS, found in ~95% of PDAC, in supporting autophagy. Surprisingly, acute KRAS suppression was associated with increased autophagic flux. Pharmacologic inhibition of ERK MAPK phenocopied the genetic silencing of KRAS and increased autophagic flux. We speculated that the loss of ERK-driven metabolic processes may induce compensatory mechanisms to increase autophagy. We then addressed whether ERK inhibition increased PDAC dependence on autophagy. Supporting this possibility, we found that cotreatment with the autophagy inhibitor chloroquine (CQ) synergistically enhanced ERK inhibitor-mediated anti-proliferative activity. Our findings, together with similar observations by others, provided the rationale for our initiation of Phase I/II clinical trials evaluating the combination of MEKi (binimetinib; NCT04132505) or ERKi (LY3214996; NCT04386057) with hydroxychloroquine (HCQ) in PDAC. Our ongoing studies are centered on developing additional combinations for targeting autophagy. First, we performed a CRISPR/Cas-9 mediated genetic loss-of-function screen in the presence of CQ to determine additional sensitizers as well as mediators of resistance to autophagy inhibition. Top sensitizers included multiple facilitators of the DNA damage response, mTOR pathway components, and genes involved in the upstream regulation of the autophagy pathway. Second, we determined that autophagic signaling is temporally regulated following RAS pathway inhibition and hypothesize that further dissection of this regulation will improve current anti-nutrient scavenging treatment strategies. We conclude that concurrent suppression of multiple metabolic processes, to block compensatory rebound activities, will be needed for effective PDAC treatment. Citation Format: Jonathan M. DeLiberty, Ryan Robb, Claire E. Gates, Noah L. Pieper, Runying Yang, Clint A. Stalnecker, Kirsten L. Bryant. Enhancing autophagy inhibition as a therapeutic strategy for pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr B007.
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- 2022
21. Oncogenic KRAS drives radioresistance through upregulation of NRF2-53BP1-mediated non-homologous end-joining repair
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Adriana Estrada-Bernal, Ryan Robb, Sunil Krishnan, Xiaokui Mo, Linlin Yang, Moumita Chatterjee, Amy Webb, Wei Chen, Changxian Shen, Terence M. Williams, and Nikhil Sebastian
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DNA End-Joining Repair ,endocrine system diseases ,DNA damage ,DNA repair ,NF-E2-Related Factor 2 ,AcademicSubjects/SCI00010 ,Apoptosis ,Biology ,Genome Integrity, Repair and Replication ,medicine.disease_cause ,Radiation Tolerance ,Proto-Oncogene Proteins p21(ras) ,Radioresistance ,Cell Line, Tumor ,Genetics ,medicine ,Gene silencing ,Humans ,DNA Breaks, Double-Stranded ,RNA, Small Interfering ,Mitotic catastrophe ,neoplasms ,Cell Proliferation ,Mutation ,DNA, Neoplasm ,HCT116 Cells ,G1 Phase Cell Cycle Checkpoints ,Survival Analysis ,digestive system diseases ,respiratory tract diseases ,Non-homologous end joining ,G2 Phase Cell Cycle Checkpoints ,Gene Expression Regulation, Neoplastic ,Gamma Rays ,Colonic Neoplasms ,Cancer research ,KRAS ,Tumor Suppressor p53-Binding Protein 1 ,Signal Transduction - Abstract
KRAS-activating mutations are oncogenic drivers and are correlated with radioresistance of multiple cancers, including colorectal cancer, but the underlying precise molecular mechanisms remain elusive. Herein we model the radiosensitivity of isogenic HCT116 and SW48 colorectal cancer cell lines bearing wild-type or various mutant KRAS isoforms. We demonstrate that KRAS mutations indeed lead to radioresistance accompanied by reduced radiotherapy-induced mitotic catastrophe and an accelerated release from G2/M arrest. Moreover, KRAS mutations result in increased DNA damage response and upregulation of 53BP1 with associated increased non-homologous end-joining (NHEJ) repair. Remarkably, KRAS mutations lead to activation of NRF2 antioxidant signaling to increase 53BP1 gene transcription. Furthermore, genetic silencing or pharmacological inhibition of KRAS, NRF2 or 53BP1 attenuates KRAS mutation-induced radioresistance, especially in G1 phase cells. These findings reveal an important role for a KRAS-induced NRF2-53BP1 axis in the DNA repair and survival of KRAS-mutant tumor cells after radiotherapy, and indicate that targeting NRF2, 53BP1 or NHEJ may represent novel strategies to selectively abrogate KRAS mutation-mediated radioresistance.
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- 2021
22. Altered Gemcitabine and Nab-paclitaxel Scheduling Improves Therapeutic Efficacy Compared with Standard Concurrent Treatment in Preclinical Models of Pancreatic Cancer
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Terence M. Williams, Zobeida Cruz-Monserrate, Arnab Chakravarti, Ryan Robb, Jose G. Trevino, Linlin Yang, Kamalakannan Palanichamy, Laith Abushahin, Adam R. Wolfe, John R. Jacob, Ahmad Hegazi, and Duan-Liang Shyu
- Subjects
0301 basic medicine ,Male ,Cancer Research ,Paclitaxel ,medicine.medical_treatment ,Caveolin 1 ,Mice, Nude ,Mice, SCID ,Deoxycytidine ,Drug Administration Schedule ,Article ,03 medical and health sciences ,0302 clinical medicine ,Mice, Inbred NOD ,Pancreatic cancer ,Albumins ,Cell Line, Tumor ,Antineoplastic Combined Chemotherapy Protocols ,medicine ,Gene silencing ,Animals ,Humans ,Cell Proliferation ,Mice, Knockout ,Chemotherapy ,business.industry ,Cell Cycle ,Albumin ,medicine.disease ,Xenograft Model Antitumor Assays ,Gemcitabine ,Tumor Burden ,Gene Expression Regulation, Neoplastic ,Pancreatic Neoplasms ,030104 developmental biology ,Treatment Outcome ,Oncology ,Apoptosis ,Cell culture ,030220 oncology & carcinogenesis ,Toxicity ,Cancer research ,business ,medicine.drug ,Carcinoma, Pancreatic Ductal - Abstract
Purpose: Concurrent gemcitabine and nab-paclitaxel treatment is one of the preferred chemotherapy regimens for metastatic and locally advanced pancreatic ductal adenocarcinoma (PDAC). Previous studies demonstrate that caveolin-1 (Cav-1) expression is critical for nab-paclitaxel uptake into tumors and correlates with response. Gemcitabine increases nab-paclitaxel uptake by increasing Cav-1 expression. Thus, we hypothesized that pretreatment with gemcitabine would further enhance the sensitivity of PDAC to nab-paclitaxel by increasing Cav-1 expression and nab-paclitaxel uptake. Experimental Design: We investigated the sensitivity of different gemcitabine and nab-paclitaxel treatment regimens in a panel of PDAC cell lines and orthotopic xenograft models. The sensitivity of different treatment regimens was compared with the standard concurrent treatment. Results: Pretreatment with gemcitabine before nab-paclitaxel increased Cav-1 and albumin uptake and significantly decreased proliferation and clonogenicity compared with concurrent treatment, which correlated with increased levels of apoptosis. Cav-1 silencing reduced the uptake of albumin, and therapeutic advantage was observed when cells were pretreated with gemcitabine prior to nab-paclitaxel. In addition, we observed that pretreatment with gemcitabine resulted in partial synchronization of cells in the G2–M-phase at the time of nab-paclitaxel treatment, providing another mechanism for the benefit of altered scheduling. In heterotopic and orthotopic xenograft models, the altered schedule of gemcitabine prior to nab-paclitaxel significantly delayed tumor growth compared with concurrent delivery without added toxicity. Conclusions: Pretreatment with gemcitabine significantly increased nab-paclitaxel uptake and correlated with an increased treatment efficacy and survival benefit in preclinical models, compared with standard concurrent treatment. These results justify preclinical and clinical testing of this altered scheduling combination.
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- 2020
23. Phase I Trial of Trametinib with Neoadjuvant Chemoradiation in Patients with Locally Advanced Rectal Cancer
- Author
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Terence M. Williams, Sameh Mikhail, Lai Wei, Ryan Robb, Cynthia Timmers, Mark Arnold, Evan Wuthrick, Christina Wu, Sameek Roychowdhury, Amy Webb, Alan Harzman, Sherif Abdel-Misih, Kristen K. Ciombor, Tanios Bekaii-Saab, Somashekar G. Krishna, Wei Chen, and Dana Backlund Cardin
- Subjects
0301 basic medicine ,Oncology ,Neuroblastoma RAS viral oncogene homolog ,Male ,Cancer Research ,medicine.medical_specialty ,Colorectal cancer ,Pyridones ,Population ,Kaplan-Meier Estimate ,Pyrimidinones ,medicine.disease_cause ,Article ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,medicine ,Clinical endpoint ,Biomarkers, Tumor ,Humans ,Molecular Targeted Therapy ,education ,Protein Kinase Inhibitors ,Aged ,Neoplasm Staging ,Trametinib ,education.field_of_study ,business.industry ,Rectal Neoplasms ,Disease Management ,Chemoradiotherapy ,Middle Aged ,medicine.disease ,Prognosis ,Combined Modality Therapy ,Neoadjuvant Therapy ,030104 developmental biology ,Treatment Outcome ,030220 oncology & carcinogenesis ,Toxicity ,Immunohistochemistry ,Female ,KRAS ,Neoplasm Grading ,business - Abstract
Purpose: The RAS/RAF/MEK/ERK signaling pathway is critical to the development of colorectal cancers, and KRAS, NRAS, and BRAF mutations foster resistance to radiation. We performed a phase I trial to determine the safety of trametinib, a potent MEK1/2 inhibitor, with 5-fluorouracil (5-FU) chemoradiation therapy (CRT) in patients with locally advanced rectal cancer (LARC). Patients and Methods: Patients with stage II/III rectal cancer were enrolled on a phase I study with 3+3 study design, with an expansion cohort of 9 patients at the MTD. Following a 5-day trametinib lead-in, with pre- and posttreatment tumor biopsies, patients received trametinib and CRT, surgery, and adjuvant chemotherapy. Trametinib was given orally daily at 3 dose levels: 0.5 mg, 1 mg, and 2 mg. CRT consisted of infusional 5-FU 225 mg/m2/day and radiation dose of 28 daily fractions of 1.8 Gy (total 50.4 Gy). The primary endpoint was to identify the MTD and recommended phase II dose. IHC staining for phosphorylated ERK (pERK) and genomic profiling was performed on the tumor samples. Results: Patients were enrolled to all dose levels, and 18 patients were evaluable for toxicities and responses. Treatment was well tolerated, and there was one dose-limiting toxicity of diarrhea, which was attributed to CRT rather than trametinib. At the 2 mg dose level, 25% had pathologic complete response. IHC staining confirmed dose-dependent decrease in pERK with increasing trametinib doses. Conclusions: The combination of trametinib with 5-FU CRT is safe and well tolerated, and may warrant additional study in a phase II trial, perhaps in a RAS/RAF-mutant selected population.
- Published
- 2019
24. Inhibiting BRAF Oncogene-Mediated Radioresistance Effectively Radiosensitizes BRAF(V600E) Mutant Thyroid Cancer Cells by Constraining DNA Double-strand Break Repair
- Author
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Changxian Shen, Ryan Robb, Motoyasu Saji, Terence M. Williams, Marally Vedaie, Linlin Yang, Amy Webb, Xiaoli Zhang, Matthew D. Ringel, Adam R. Wolfe, and Sissy M. Jhiang
- Subjects
0301 basic medicine ,Cancer Research ,endocrine system diseases ,DNA repair ,medicine.medical_treatment ,Article ,03 medical and health sciences ,0302 clinical medicine ,Radioresistance ,medicine ,Vemurafenib ,Clonogenic assay ,skin and connective tissue diseases ,Thyroid cancer ,neoplasms ,Oncogene ,business.industry ,Thyroid ,medicine.disease ,digestive system diseases ,Radiation therapy ,enzymes and coenzymes (carbohydrates) ,030104 developmental biology ,medicine.anatomical_structure ,Oncology ,030220 oncology & carcinogenesis ,Cancer research ,business ,medicine.drug - Abstract
Purpose: Activating BRAF mutations, most commonly BRAFV600E, are a major oncogenic driver of many cancers. We explored whether BRAFV600E promotes radiation resistance and whether selectively targeting BRAFV600E with a BRAF inhibitor (vemurafenib, BRAFi) sensitizes BRAFV600E thyroid cancer cells to radiotherapy. Experimental Design: Immunoblotting, neutral comet, immunocytochemistry, functional reporter, and clonogenic assays were used to analyze the outcome and molecular characteristics following radiotherapy with or without BRAFV600E or vemurafenib in thyroid cancer cells. Results: BRAFV600E thyroid cancer cell lines were associated with resistance to ionizing radiation (IR), and expression of BRAFV600E into wild-type BRAF thyroid cancer cells led to IR resistance. BRAFi inhibited ERK signaling in BRAFV600E mutants, but not BRAF wild-type thyroid cancer cell lines. BRAFi selectively radiosensitized and delayed resolution of IR-induced γH2AX nuclear foci in BRAFV600E cells. Moreover, BRAFi impaired global DNA repair and altered the resolution of 53BP1 and RAD51 nuclear foci in BRAFV600E cells following IR. BRAFV600E mutants displayed enhanced nonhomologous end-joining (NHEJ) repair activity, which was abolished by BRAFi. Intriguingly, BRAFV600E mutation led to upregulation of XLF, a component of NHEJ, which was prevented by BRAFi. Importantly, BRAFi in combination with radiotherapy resulted in marked and sustained tumor regression of BRAFV600E thyroid tumor xenografts. Conclusions: BRAFV600E mutation promotes NHEJ activity leading to radioresistance and BRAFi selectively radiosensitizes BRAFV600E thyroid cancer cells through inhibiting NHEJ. Our findings suggest that combining BRAFi and radiation may improve the therapeutic outcome of patients with BRAFV600E-mutant thyroid cancer.
- Published
- 2019
25. Abstract B60: Optimization of biologic scheduling of gemcitabine and abraxane improves treatment response compared to the standard concurrent regimen in preclinical models of pancreatic cancer
- Author
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Terence M. Williams, Duan-Liang Shyu, Ahmad Hegazi, Adam R. Wolfe, Laith Abushahin, and Ryan Robb
- Subjects
Oncology ,Cancer Research ,medicine.medical_specialty ,Chemotherapy ,endocrine system diseases ,business.industry ,medicine.medical_treatment ,Combination chemotherapy ,computer.file_format ,medicine.disease ,Gemcitabine ,chemistry.chemical_compound ,Regimen ,Paclitaxel ,chemistry ,Tumor progression ,Pancreatic cancer ,Internal medicine ,Medicine ,ABX test ,business ,computer ,medicine.drug - Abstract
Introduction: Gemcitabine (gem) and Abraxane (albumin-bound paclitaxel, abx) combination chemotherapy delivered on the same day is now one of the preferred chemotherapy regimens for metastatic and locally advanced pancreatic ductal adenocarcinoma (PDAC) based on results of the phase III MPACT clinical trial that showed improved overall survival of gem+abx compared to gem alone in the metastatic/advanced setting. Our previous published works revealed that caveolin-1 (Cav-1), the principal structural component of caveolae and mediator of endocytosis, is highly expressed in PDAC cells and associated with enhanced tumor progression and resistance to gem in PDAC preclinical models. We also found that loss of Cav-1 through genetic knockdown inhibited both PDAC cell uptake of albumin and response to albumin-based chemotherapies, i.e., abx. In addition, gem treatment resulted in a time-dependent increase in Cav-1 protein expression. Taken together, we hypothesized pretreatment with gem would increase the efficacy of the gem/abx combination via increased Cav-1 dependent albumin-bound chemotherapy uptake. Results: ASPC1 and HPAFII PDAC cell lines were exposed to gem (25-100nM) for 24-48 hours followed by a 1-hour albumin pulse and displayed a time-dependent increase in intracellular albumin via Western blotting. We next tested PDAC cell proliferation and cell survival via alamarBlue and colony formation assays with various different gem/abx scheduling combinations. HPAFII and ASPC1 cells were treated for 24 hours with the following schedules: (1) vehicle, (2) gem alone, (3) abx alone, (4) gem+abx on same day (d1gem+abx), (5) gem on day 1 and abx day 2 (d1gem_d2abx), or (6) gem on day 1, no drug on day 2 and abx on day 3 (d1gem_d3abx). Both alternative schedules of d1gem_d2abx and d1gem_d3abx had greater inhibition of proliferation and colony formation compared to the current standard of care d1gem+abx, and of all the combinations, d1gem_d3abx was the most efficacious (p Conclusion: We found 24- to 48-hour gem treatment increased albumin uptake, leading to maximal treatment efficacy with an optimized schedule of gem delivered on day 1 and abx on day 3 compared to the standard gem+abx administered on the same day. These findings support further testing of an altered and biologically optimized scheduling of gemcitabine and Abraxane. Citation Format: Adam R. Wolfe, Ryan Robb, Ahmad Hegazi, Duan-Liang Shyu, Laith Abushahin, Terence M. Williams. Optimization of biologic scheduling of gemcitabine and abraxane improves treatment response compared to the standard concurrent regimen in preclinical models of pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr B60.
- Published
- 2019
26. BRAF Oncogenic Activation Induces Radioresistance Through Non-homologous End-Joining Repair Which is Abrogated by Targeted Inhibition of BRAF Mutational Activity
- Author
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Linlin Yang, Terence M. Williams, M. Ringel, M. Saji, Ryan Robb, and C. Shen
- Subjects
0301 basic medicine ,Non-homologous end joining ,03 medical and health sciences ,Cancer Research ,030104 developmental biology ,Radiation ,Oncology ,business.industry ,Radioresistance ,Cancer research ,Medicine ,Radiology, Nuclear Medicine and imaging ,business - Published
- 2018
27. A KRAS-NRF2-53BP1 Nonhomologous End-Joining Repair Pathway Mediates Oncogenic KRAS Radioresistance
- Author
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Linlin Yang, Terence M. Williams, Ryan Robb, Adriana Estrada-Bernal, and Moumita Chatterjee
- Subjects
Non-homologous end joining ,Cancer Research ,Radiation ,Oncology ,business.industry ,Radioresistance ,Cancer research ,Medicine ,Radiology, Nuclear Medicine and imaging ,KRAS ,business ,medicine.disease_cause - Published
- 2017
28. Abstract 5186: Vemurafenib selectively radiosensitizes BRAF V600E mutant papillary and anaplastic thyroid carcinoma cells
- Author
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Ryan Robb, Linlin Yang, and Terence M. Williams
- Subjects
0301 basic medicine ,Oncology ,Cancer Research ,medicine.medical_specialty ,endocrine system diseases ,business.industry ,Cancer ,medicine.disease ,Papillary thyroid cancer ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,Internal medicine ,Radioresistance ,medicine ,Cancer research ,Anaplastic thyroid cancer ,Vemurafenib ,Clonogenic assay ,business ,Thyroid cancer ,030217 neurology & neurosurgery ,V600E ,medicine.drug - Abstract
BRAF activating mutations act as oncogenic drivers and are highly prevalent in thyroid cancer, occurring in about 60% of papillary thyroid cancer (PTC) as well as 30-40% anaplastic thyroid cancer (ATC). MAPK signaling and treatment resistance is driven by BRAF mutations in thyroid cancer. Among the most common of these mutations is BRAFV600E, which can be selectively inhibited by vemurafenib. Using a panel of PTC and ATC cell lines we assessed how the presence/absence of BRAFV600E impacts radiation sensitivity. We used radiation clonogenics, comet assays, nuclear foci formation, immunoblotting, and mouse xenografts models to determine the effect of vemurafenib on PTC and ATC cells. Analysis of radiation clonogenics implicated higher radioresistance in cell lines containing the BRAFV600E mutation as compared to wild-type BRAF. Additionally, forced expression of BRAFV600E in a wild-type thyroid cancer cell line induced radioresistance. Vemurafenib inhibited MAPK signaling in V600E mutant cell lines, but showed no effect in BRAF wild-type cell lines. Vemurafenib pretreatment selectively radiosensitized BRAFV600E mutants in vitro, as assessed by radiation clonogenic assays. Comet assays revealed impairment of DNA repair in BRAFV600E lines when treated with vemurafenib and radiation. Additionally, γ-H2A.x westerns and nuclear foci staining indicated that vemurafenib pretreatment decreases the tumor cell’s ability to repair DNA double-strand breaks (DSB) in BRAFV600E cell lines. Vemurafenib also appeared to alter the kinetics of formation and resolution of 53BP1 and Rad51 nuclear foci in these cell lines. Evaluation of DSB functional repair using GFP reporter constructs, suggests that BRAFV600E induces NHEJ repair, which can be attenuated by vemurafenib treatment. Finally, vemurafenib effectively increases radiosensitivity of BRAF V600E tumors in vivo. From our results, BRAF activating mutation appears to be associated with radioresistance. Vemurafenib selectively radiosensitizes both PTC and ATC cells through inhibition of DNA repair mechanisms. Combining vemurafenib and radiation may improve therapeutic control for BRAFV600E mutant thyroid cancers. Citation Format: Ryan N. Robb, Linlin Yang, Terence Williams. Vemurafenib selectively radiosensitizes BRAF V600E mutant papillary and anaplastic thyroid carcinoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5186. doi:10.1158/1538-7445.AM2017-5186
- Published
- 2017
29. Abstract CT088: A phase I trial combining MEK-1/2 inhibition in combination with 5-fluorouracil and radiation for locally-advanced rectal adenocarcinoma
- Author
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Cynthia Timmers, Evan Wuthrick, Emily Chan, Amy Webb, Tanios Bekaii-Saab, Sameek Roychowdhury, Ryan Robb, Christina Wu, Lai Wei, and Terence M. Williams
- Subjects
0301 basic medicine ,Trametinib ,Oncology ,Cancer Research ,medicine.medical_specialty ,Colorectal cancer ,business.industry ,medicine.medical_treatment ,Cancer ,medicine.disease ,Total mesorectal excision ,Radiation therapy ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,Tolerability ,Fluorouracil ,Internal medicine ,medicine ,Rectal Adenocarcinoma ,030211 gastroenterology & hepatology ,business ,medicine.drug - Abstract
Introduction: 5-fluorouracil (5-FU)-based chemoradiation (CRT) is a standard neoadjuvant treatment strategy for the treatment of locally-advanced rectal adenocarcinomas (LARC). MEK-1/2 inhibition has been shown to radiosensitize Ras mutant tumors in preclinical models, including colorectal cancer. In this phase 1 trial, we are testing MEK-1/2 inhibition in combination with neoadjuvant CRT for LARC. Methods: This trial is a standard 3+3 design testing 3 dose levels of the MEK-1/2 inhibitor trametinib in combination with CRT: 0.5 mg, 1.0 mg, and 2.0 mg daily, followed by an expansion cohort. All patients first receive a one week lead-in dosing of trametinib monotherapy, and undergo a tumor biopsy at the end of that week to assess pharmacodynamic inhibition by immunohistochemistry (IHC). Then, patients receive standard CRT (5-FU 225 mg/m2 per day by continuous infusion during radiotherapy, and 50.4 Gy in 28 fractions, 5 days/ week) in combination with trametinib (5 days/week). Patients have total mesorectal excision (TME) 6-10 weeks after completion of CRT. Results: 17 patients have been enrolled to date, with current enrollment occurring on the trametinib 2 mg expansion cohort (total 18 patients planned). Of these, 15 patients (10 males, 5 females) have toxicity and surgical response data available. Median age is 53 years (range 35-74 years), and 6 patients have Stage II disease, while 9 patients with Stage III disease. There have been no grade 4-5 toxicities. One dose-limiting toxicity (DLT) of diarrhea occurred in the 2mg dose cohort, attributed mainly to 5FU CRT, but led to trametinib discontinuation. Generalized skin rash led to trametinib discontinuation after 2 weeks of therapy for 1 patient and was held for 3 days for 2 patients. All patients completed TME, and 3 patients had wound infection at 2 weeks after TME, while 2 patients had perineal wound infection at 4 weeks after TME. Three out of 9 (33%) patients at the 2mg dose cohort had a pathologic complete response (pCR), and 2/9 (22%) patients had a near pCR. Adjuvant chemotherapy was given to 10 patients, 4 patients did not receive (3 refused), and 1 patient is pending. Correlative research studies have been performed in the first 12 patients enrolled. Examination of phospho-ERK levels using Vectra quantitative immunohistochemistry in pre-treatment versus post-lead-in trametinib tumor tissue reveals dose-dependent decreases in p-ERK expression in both tumor and stromal tissue as trametinib is increased from 0.5 to 2.0 mg (range 18-46% absolute reduction), with maximal reduction observed in the 2 mg cohort. Additionally, we have performed whole exome sequencing of a custom panel of 279 cancer associated genes (IGNITE platform) in tumor and normal tissue, and have identified high frequency mutations in KRAS, BRAF, and TP53, as well as additional lower frequency mutations in every tumor. One patient was noted to have microsatellite instability. Finally, we will present data correlating degree of change in p-ERK staining, mutational analysis, and mismatch repair status with pathologic response. Conclusions: The combination of trametinib with 5-FU-based CRT for LARC is feasible with promising signs of clinical activity and tolerability. Initial analysis of tumor tissue confirms dose-dependent pharmacodynamic inhibition of ERK-1/2 within 5 days of starting trametinib. Citation Format: Terence M. Williams, Christina Wu, Lai Wei, Emily Chan, Ryan Robb, Sameek Roychowdhury, Amy Webb, Cynthia Timmers, Tanios Bekaii-Saab, Evan Wuthrick. A phase I trial combining MEK-1/2 inhibition in combination with 5-fluorouracil and radiation for locally-advanced rectal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT088. doi:10.1158/1538-7445.AM2017-CT088
- Published
- 2017
30. KRAS Oncogenic Mutations Induce Intrinsic Resistance to Radiation Through Up-Regulation of DNA Repair Pathways
- Author
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Terence M. Williams, Linlin Yang, Ryan Robb, A. Estrada, and Moumita Chatterjee
- Subjects
Cancer Research ,Radiation ,business.industry ,DNA repair ,Intrinsic resistance ,medicine.disease_cause ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Oncology ,Downregulation and upregulation ,030220 oncology & carcinogenesis ,Cancer research ,Medicine ,Radiology, Nuclear Medicine and imaging ,KRAS ,business - Published
- 2016
31. Getting musical mileage from simple patterns
- Author
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Ryan, Robb
- Subjects
Musical performance -- Methods ,Drums (Musical instruments) -- Usage ,Arts, visual and performing ,Regional focus/area studies - Abstract
Many drummers will work at a new pattern until they nail it, but only play it verbatim and not explore all the additional musical mileage that is available to them. [...]
- Published
- 2017
32. Developing your weaker hand
- Author
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Ryan, Robb
- Subjects
Drums (Musical instruments) -- Usage ,Percussion music -- Methods ,Arts, visual and performing ,Regional focus/area studies - Abstract
As drummers, we all face the same dilemma: our weak hand is just not up to par with our lead hand. In most cases, it's not even close. The reason [...]
- Published
- 2016
33. Abstract 405: Caveolin-1 expression mediates response to albumin-bound paclitaxel
- Author
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Thirumoorthy Krishnan, Palanichamy Kamalakanan, Edgar Ben-Josef, Arnab Chakravarti, Moumita Chatterjee, Marally Vedaie, Terence M. Williams, Star Seum, and Ryan Robb
- Subjects
Cancer Research ,Pathology ,medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,Cancer ,medicine.disease ,Flow cytometry ,chemistry.chemical_compound ,Oncology ,Paclitaxel ,chemistry ,Downregulation and upregulation ,Cell culture ,Apoptosis ,Annexin ,Pancreatic cancer ,cardiovascular system ,medicine ,Cancer research ,business - Abstract
BACKGROUND: Albumin-bound chemotherapies such as nab-paclitaxel are approved to treat pancreatic cancer, non-small cell lung cancer (NSCLC), and breast cancer. Predictive biomarkers to select patients who may benefit most from nab-paclitaxel are lacking. Nab-paclitaxel is thought to enter cells through a caveolae-gp60 endocytic mechanism. Caveolin-1 (Cav-1) is a principal structural component of caveolae, and Cav-1 has been shown to be important for albumin uptake in endothelial cells. Cav-1 is known to be up-regulated in multiple tumor types, including pancreatic cancer, and certain subtypes of non-small cell lung cancer, and breast cancer. We hypothesize that Cav-1 expression may predict response to nab-paclitaxel therapy. METHODS: We correlated Cav-1 expression with nab-paclitaxel sensitivity in a panel of NSCLC and pancreatic cancer cell lines. We also assessed albumin uptake in tumor and non-tumor cell lines. We genetically depleted Cav-1 by shRNA in cells and performed cytotoxicity assays. In addition, we measured how Cav-1 levels affected albumin and nab-paclitaxel uptake into tumor cells by immunofluorescence, immunoblotting, and mass spectrometry. Annexin V flow cytometry analysis and immunoblotting for apoptosis pathway intermediates were also performed. Nab-paclitaxel resistant cell lines were created by culturing cells with increasing doses of nab-paclitaxel for extended periods of time. The role of Cav-1 expression in mediating response to nab-paclitaxel in vivo was assessed using xenograft models. RESULTS: H23 and MIA-PaCa2 tumor cells uptake more albumin compared to FHs74Int and HBEC3KT non-tumor cell lines. Higher Cav-1 expression in a panel of pancreatic cancer and NSCLC cell lines was correlated with lower IC50 for nab-paclitaxel. Cav-1 depletion resulted in reduced albumin and nab-paclitaxel uptake by tumor cells as measured by immunofluorescence, immunoblotting, and mass spectrometry. Loss of Cav-1 resulted in resistance to nab-paclitaxel but no change in sensitivity to free paclitaxel in vitro. Cav-1 down-regulation resulted in protection from nab-paclitaxel-induced apoptosis. Conversely, re-expression of Cav-1 in low-Cav-1 endogenously expressing cell lines AsPC-1 and HPAFII resulted in increased nab-paclitaxel uptake and sensitization through apoptosis. Furthermore, nab-paclitaxel resistant cells generated by prolonged exposure demonstrated downregulation of Cav-1 levels and reduced albumin uptake. Finally, genetic depletion of Cav-1 rendered tumor cells resistant to nab-paclitaxel in xenograft models, with concomitant reduced albumin uptake and activation of apoptosis. CONCLUSIONS: Our data suggest that Cav-1 expression and caveolae are critical determinants of response to nab-paclitaxel. This data supports further testing of Cav-1 as a potential predictive biomarker of response to nab-paclitaxel and potentially other albumin-bound chemotherapies. Citation Format: Terence M. Williams, Moumita Chatterjee, Ryan Robb, Marally Vedaie, Star Seum, Thirumoorthy Krishnan, Palanichamy Kamalakanan, Edgar Ben-Josef, Arnab Chakravarti. Caveolin-1 expression mediates response to albumin-bound paclitaxel. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 405.
- Published
- 2016
34. Abstract CT025: A phase I trial combining MEK-1/2 inhibition in combination with 5-fluorouracil and radiation for KRAS, BRAF, and NRAS mutant locally advanced rectal adenocarcinoma
- Author
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Terence M. Williams, Tanios Bekaii-Saab, Cynthia Timmers, Evan Wuthrick, Ryan Robb, and Christina Wu
- Subjects
Neuroblastoma RAS viral oncogene homolog ,Trametinib ,Oncology ,Cancer Research ,medicine.medical_specialty ,Colorectal cancer ,business.industry ,medicine.medical_treatment ,Cancer ,medicine.disease ,medicine.disease_cause ,Surgery ,Tolerability ,Internal medicine ,medicine ,KRAS ,business ,Neoadjuvant therapy ,V600E - Abstract
Introduction: 5-fluorouracil (5-FU)-based chemoradiation (CRT) is a standard neoadjuvant treatment strategy for the treatment of locally-advanced rectal adenocarcinomas (LARC). MEK-1/2 inhibition has been shown to radiosensitize Ras mutant tumors in preclinical models, including colorectal cancer. In this phase 1 trial, we will test MEK-1/2 inhibition in combination with neoadjuvant CRT for LARC. Methods: This trial is a standard 3+3 design testing 3 dose levels of the MEK-1/2 inhibitor trametinib (GSK1120212) in combination with CRT: 0.5 mg, 1.0 mg, and 2.0 mg daily, followed by an expansion cohort. All patients first receive a one week lead-in dosing of trametinib monotherapy, and undergo a tumor biopsy at the end of that week to assess pharmacodynamic inhibition by immunohistochemistry (IHC). Then, patients receive standard CRT (5-FU 225 mg/m2 per day by continuous infusion during radiotherapy, and 50.4 Gy in 28 fractions, 5 days/ week) in combination with trametinib (5 days/week). Patients have total mesorectal excision (TME) 6-10 weeks after completion of CRT. Results: The trial opened in 2013, and 31 patients have been screened for KRAS/BRAF/NRAS activating mutations, of which 11 (35.4%) tested positive for a mutation. Of these, 9 patients (8 male, 1 female) have been enrolled so far, with 3 patients accrued in each dose level. Regarding mutation status, six patients have KRAS mutations (five G12V, one G13D), two patients have BRAF mutations (one V600E, one D594N), and one patient is unknown (in dose level 1). Age of patients ranges from 38-64 years old (median 55). All patients have successfully completed neoadjuvant therapy and TME (5 low anterior resection, 4 abdominal-perineal resection). No dose-limiting toxicities were observed on dose levels 1 and 2, and additional patients are currently being accrued onto dose level 3 (2.0 mg). One patient in dose level 3 had pathologic complete response (pCR) at the time of TME. Examination of pre-treatment tumor tissue by IHC reveals baseline hyperactivation of ERK-1/2 (p42/44 MAPK) in most tumors with some heterogeneity in levels of phospho-ERK staining, reflecting hyperactivation of the RAS/RAF-MAPK pathway. Qualitatively, ERK-1/2 activity is reduced from pre-treatment to post-trametinib lead-in tumor tissue, particularly in patients on dose level 3. The patient who experienced a pCR had the most significant reduction in ERK-1/2 activity in tumor tissue and tumor-associated stroma. We will also present quantitative data demonstrating ERK-1/2 inhibition using Vectra quantitative immunohistochemistry. Conclusions: The combination of trametinib with 5-FU-based CRT for LARC is feasible with promising signs of clinical activity and tolerability. Ongoing enrollment will further assess safety, tolerability, and determine the maximally-tolerated dose of trametinib. Initial analysis of tumor tissue suggests dose-dependent pharmacodynamic inhibition of ERK-1/2 within 5 days of starting trametinib. Citation Format: Terence M. Williams, Evan Wuthrick, Christina Wu, Ryan Robb, Cynthia Timmers, Tanios Bekaii-Saab. A phase I trial combining MEK-1/2 inhibition in combination with 5-fluorouracil and radiation for KRAS, BRAF, and NRAS mutant locally advanced rectal adenocarcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr CT025.
- Published
- 2016
35. Abstract B8: Caveolae-mediated endocytosis is critical for tumor cell response to nab-paclitaxel
- Author
-
Star Seum, Chen Lin, Adriana Estrada-Bernal, Moumita Chatterjee, Arnab Chakravarti, Thirumoorthy Krishnan, Terence M. Williams, Palanichamy Kamalakanan, Marall Vedaie, and Ryan Robb
- Subjects
Cancer Research ,Tumor microenvironment ,medicine.diagnostic_test ,biology ,Cancer ,biology.organism_classification ,medicine.disease ,Gemcitabine ,Flow cytometry ,chemistry.chemical_compound ,Nude mouse ,Oncology ,Paclitaxel ,chemistry ,Cell culture ,Pancreatic cancer ,Immunology ,cardiovascular system ,Cancer research ,medicine ,medicine.drug - Abstract
INTRODUCTION: Pancreatic cancer is the fourth leading cause of cancer-related deaths in the United States and is typified by poor outcomes. Gemcitabine with nab-paclitaxel is a standard chemotherapy combination which recently demonstrated superiority compared to gemcitabine alone in a randomized trial. However, a predictive biomarker to select patients who may benefit from nab-paclitaxel is currently lacking. Nab-paclitaxel is a nanoparticle composed of paclitaxel bound to human albumin. Caveolin-1 (Cav-1) is a 22kD structural component of caveolae, 50-100 nM invaginations of the cell membrane. Cav-1 has been demonstrated to be an important component of albumin uptake in endothelial cells, and Cav-1 is overexpressed in pancreatic cancer. We hypothesize that Cav-1 expression may predict response to nab-paclitaxel therapy. METHODS: We compared Cav-1 expression to nab-paclitaxel sensitivity in a panel of pancreatic and non-small cell lung cancer cell lines. We stably knocked down Cav-1 expression in H23 and MIA-PaCa2 cells and performed cytotoxicity assays. In addition, we measured albumin and nab-paclitaxel uptake into tumor cells with immunoblotting, immunofluorescence and mass spectrometry. Sensitivity to the therapy was confirmed by quantifying apoptosis via flow cytometry and immunoblotting for activation of apoptotic pathway intermediates. Nab-paclitaxel resistant cell lines were created by selecting resistant cells over a period of time. Results were confirmed in vivo in a nude mouse model. RESULTS: Cav-1 expression in a panel of pancreatic cancer and non-small cell lung cancer (NSCLC) cell lines negatively correlated with their corresponding IC50 values for nab-paclitaxel, indicating a positive correlation with sensitivity to nab-paclitaxel. Cav-1 depletion resulted in reduced albumin uptake in tumor cells, reduced intracellular paclitaxel, and protection from nab-paclitaxel both in vitro and in vivo, while overexpression of Cav-1 enhanced sensitivity to nab-paclitaxel. Creation of nab-paclitaxel resistant cell lines demonstrated loss of Cav-1 expression in resistant cells. In support of our preclinical data, higher Cav-1 expression in the tumor microenvironment in patients with metastatic cancer treated with nab-paclitaxel also correlates with improved response and longer survival. CONCLUSIONS: Our data indicate that Cav-1 expression mediates entry of albumin and nab-paclitaxel, subsequent response to nab-paclitaxel, and that downregulation or re-expression of Cav-1 impairs or facilitates nab-paclitaxel uptake and response, respectively. This data supports further testing of Cav-1 as a potential predictive biomarker of response to nab-paclitaxel. Citation Format: Moumita Chatterjee, Marall Vedaie, Ryan Robb, Star Seum, Adriana Estrada-Bernal, Thirumoorthy Krishnan, Palanichamy Kamalakanan, Chen Lin, Arnab Chakravarti, Terence M. Williams. Caveolae-mediated endocytosis is critical for tumor cell response to nab-paclitaxel. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B8.
- Published
- 2015
36. COMMENTS.
- Author
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Marques, Ric, Fine, Spencer, Wacker, Bill, Schumacher, Adam, and Ryan, Robb
- Subjects
COMPUTERS ,VIDEO games ,DATA disk drives ,BLU-ray technology - Abstract
The article presents questions and answers related to computers including what kind of upgrade may be done on a gaming rig or gaming computer, why optical drives that are not Blu-ray burners are still being recommended, and the comparison of gaming personal computers from several companies including Maingear, Digital Storm, and Origin PC.
- Published
- 2010
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