1
|
Parajuli P, Craig DB, Gadgeel M, Bagla S, Wright RE, Chu R, Shanti CM, Thirunagari R, Grover SK, Ravindranath Y. Defective monocyte plasticity and altered cAMP pathway characterize USB1-mutated poikiloderma with neutropenia Clericuzio type. Br J Haematol 2024; 204:683-693. [PMID: 37779259 DOI: 10.1111/bjh.19128] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 08/22/2023] [Accepted: 09/15/2023] [Indexed: 10/03/2023]
Abstract
Poikiloderma with neutropenia (PN) Clericuzio type (OMIM #604173) is a rare disease with areas of skin hyper- and hypopigmentation caused by biallelic USB1 variants. The current study was spurred by poor healing of a perianal tear wound in one affected child homozygous for c.266-1G>A (p.E90Sfster8) mutation, from a family reported previously. Treatment with G-CSF/CSF3 or GM-CSF/CSF2 transiently increased neutrophil/monocytes count with no effect on wound healing. Analysis of peripheral blood revealed a lack of non-classical (CD14+/- CD16+ ) monocytes, associated with a systemic inflammatory cytokine profile, in the two affected brothers. Importantly, despite normal expression of cognate receptors, monocytes from PN patients did not respond to M-CSF or IL-34 in vitro, as determined by cytokine secretion or CD16 expression. RNAseq of monocytes showed 293 differentially expressed genes, including significant downregulation of GATA2, AKAP6 and PDE4DIP that are associated with leucocyte differentiation and cyclic adenosine monophosphate (cAMP) signalling. Notably, the plasma cAMP was significantly low in the PN patients. Our study revealed a novel association of PN with a lack of non-classical monocyte population. The defects in monocyte plasticity may contribute to disease manifestations in PN and a defective cAMP signalling may be the primary effect of the splicing errors caused by USB1 mutation.
Collapse
Affiliation(s)
- Prahlad Parajuli
- Department of Pharmaceutical and Health Sciences, Eugene Applebaum College of Pharmacy, Wayne State University, Detroit, Michigan, USA
- Barbara Ann Karmanos Cancer Institute, Michigan, Detroit, USA
| | - Douglas B Craig
- Barbara Ann Karmanos Cancer Institute, Michigan, Detroit, USA
- Department of Pediatrics, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Manisha Gadgeel
- Children's Hospital of Michigan, Detroit Medical Center, Detroit, Michigan, USA
- Central Michigan University, Mt. Pleasant, Michigan, USA
| | - Shruti Bagla
- Department of Pediatrics, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Robert E Wright
- Department of Pharmaceutical and Health Sciences, Eugene Applebaum College of Pharmacy, Wayne State University, Detroit, Michigan, USA
| | - Roland Chu
- Children's Hospital of Michigan, Detroit Medical Center, Detroit, Michigan, USA
- Central Michigan University, Mt. Pleasant, Michigan, USA
| | - Christina M Shanti
- Children's Hospital of Michigan, Detroit Medical Center, Detroit, Michigan, USA
| | - Rajeev Thirunagari
- Children's Hospital of Michigan, Detroit Medical Center, Detroit, Michigan, USA
| | - Sudershan K Grover
- Children's Hospital of Michigan, Detroit Medical Center, Detroit, Michigan, USA
| | - Yaddanapudi Ravindranath
- Barbara Ann Karmanos Cancer Institute, Michigan, Detroit, USA
- Department of Pediatrics, Wayne State University School of Medicine, Detroit, Michigan, USA
- Children's Hospital of Michigan, Detroit Medical Center, Detroit, Michigan, USA
| |
Collapse
|
2
|
Nguyen TM, Craig DB, Tran D, Nguyen T, Draghici S. A novel approach for predicting upstream regulators (PURE) that affect gene expression. Sci Rep 2023; 13:18571. [PMID: 37903768 PMCID: PMC10616115 DOI: 10.1038/s41598-023-41374-0] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 08/25/2023] [Indexed: 11/01/2023] Open
Abstract
External factors such as exposure to a chemical, drug, or toxicant (CDT), or conversely, the lack of certain chemicals can cause many diseases. The ability to identify such causal CDTs based on changes in the gene expression profile is extremely important in many studies. Furthermore, the ability to correctly infer CDTs that can revert the gene expression changes induced by a given disease phenotype is a crucial step in drug repurposing. We present an approach for Predicting Upstream REgulators (PURE) designed to tackle this challenge. PURE can correctly infer a CDT from the measured expression changes in a given phenotype, as well as correctly identify drugs that could revert disease-induced gene expression changes. We compared the proposed approach with four classical approaches as well as with the causal analysis used in Ingenuity Pathway Analysis (IPA) on 16 data sets (1 rat, 5 mouse, and 10 human data sets), involving 8 chemicals or drugs. We assessed the results based on the ability to correctly identify the CDT as indicated by its rank. We also considered the number of false positives, i.e. CDTs other than the correct CDT that were reported to be significant by each method. The proposed approach performed best in 11 out of the 16 experiments, reporting the correct CDT at the very top 7 times. IPA was the second best, reporting the correct CDT at the top 5 times, but was unable to identify the correct CDT at all in 5 out of the 16 experiments. The validation results showed that our approach, PURE, outperformed some of the most popular methods in the field. PURE could effectively infer the true CDTs responsible for the observed gene expression changes and could also be useful in drug repurposing applications.
Collapse
Affiliation(s)
- Tuan-Minh Nguyen
- Department of Computer Science, Wayne State University, Detroit, 48202, USA
| | - Douglas B Craig
- Department of Computer Science, Wayne State University, Detroit, 48202, USA
- Department of Oncology, School of Medicine, Wayne State University, Detroit, MI, 48201, USA
| | - Duc Tran
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Tin Nguyen
- Department of Computer Science and Software Engineering, Auburn University, Auburn, 36849, USA
| | - Sorin Draghici
- Department of Computer Science, Wayne State University, Detroit, 48202, USA.
- Advaita Bioinformatics, Ann Arbor, MI, 48105, USA.
| |
Collapse
|
3
|
Adzibolosu N, Alvero AB, Ali-Fehmi R, Gogoi R, Corey L, Tedja R, Chehade H, Gogoi V, Morris R, Anderson M, Vitko J, Lam C, Craig DB, Draghici S, Rutherford T, Mor G. Immunological modifications following chemotherapy are associated with delayed recurrence of ovarian cancer. Front Immunol 2023; 14:1204148. [PMID: 37435088 PMCID: PMC10331425 DOI: 10.3389/fimmu.2023.1204148] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 06/12/2023] [Indexed: 07/13/2023] Open
Abstract
Introduction Ovarian cancer recurs in most High Grade Serous Ovarian Cancer (HGSOC) patients, including initial responders, after standard of care. To improve patient survival, we need to identify and understand the factors contributing to early or late recurrence and therapeutically target these mechanisms. We hypothesized that in HGSOC, the response to chemotherapy is associated with a specific gene expression signature determined by the tumor microenvironment. In this study, we sought to determine the differences in gene expression and the tumor immune microenvironment between patients who show early recurrence (within 6 months) compared to those who show late recurrence following chemotherapy. Methods Paired tumor samples were obtained before and after Carboplatin and Taxol chemotherapy from 24 patients with HGSOC. Bioinformatic transcriptomic analysis was performed on the tumor samples to determine the gene expression signature associated with differences in recurrence pattern. Gene Ontology and Pathway analysis was performed using AdvaitaBio's iPathwayGuide software. Tumor immune cell fractions were imputed using CIBERSORTx. Results were compared between late recurrence and early recurrence patients, and between paired pre-chemotherapy and post-chemotherapy samples. Results There was no statistically significant difference between early recurrence or late recurrence ovarian tumors pre-chemotherapy. However, chemotherapy induced significant immunological changes in tumors from late recurrence patients but had no impact on tumors from early recurrence patients. The key immunological change induced by chemotherapy in late recurrence patients was the reversal of pro-tumor immune signature. Discussion We report for the first time, the association between immunological modifications in response to chemotherapy and the time of recurrence. Our findings provide novel opportunities to ultimately improve ovarian cancer patient survival.
Collapse
Affiliation(s)
- Nicholas Adzibolosu
- C. S. Mott Center for Human Growth and Development, Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, United States
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, United States
| | - Ayesha B. Alvero
- C. S. Mott Center for Human Growth and Development, Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, United States
- Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI, United States
| | - Rouba Ali-Fehmi
- C. S. Mott Center for Human Growth and Development, Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, United States
- Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI, United States
| | - Radhika Gogoi
- C. S. Mott Center for Human Growth and Development, Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, United States
- Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI, United States
| | - Logan Corey
- C. S. Mott Center for Human Growth and Development, Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, United States
- Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI, United States
| | - Roslyn Tedja
- C. S. Mott Center for Human Growth and Development, Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, United States
- Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI, United States
| | - Hussein Chehade
- C. S. Mott Center for Human Growth and Development, Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, United States
- Center of Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, United States
| | - Vir Gogoi
- C. S. Mott Center for Human Growth and Development, Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, United States
| | - Robert Morris
- Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI, United States
| | - Matthew Anderson
- Department of Obstetrics and Gynecology, University of South Florida Morsani College of Medicine, Tampa, FL, United States
| | - Julie Vitko
- Department of Pathology and Cell Biology, University of South Florida Morsani College of Medicine, Tampa, FL, United States
| | - Clarissa Lam
- Department of Gynecologic Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, United States
| | - Douglas B. Craig
- Department of Computer Science, Wayne State University College of Engineering, Detroit, MI, United States
- Department of Oncology, Wayne State University School of Medicine, Detroit, MI, United States
| | - Sorin Draghici
- C. S. Mott Center for Human Growth and Development, Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, United States
- Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI, United States
- Department of Computer Science, Wayne State University College of Engineering, Detroit, MI, United States
- Advaita Corporation, Ann Arbor, MI, United States
- Division of Information and Intelligent Systems, Directorate for Computer and Information Science and Engineering, National Science Foundation, Alexandria, VA, United States
| | - Thomas Rutherford
- Department of Obstetrics and Gynecology, University of South Florida Morsani College of Medicine, Tampa, FL, United States
| | - Gil Mor
- C. S. Mott Center for Human Growth and Development, Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, United States
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, United States
- Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI, United States
| |
Collapse
|
4
|
Craig DB, Malhi S, Ahmad B, Breckman K, Patel A. Electrophoretic mobility of individual molecules of alkaline phosphatase. Biochem Cell Biol 2022; 100:349-356. [PMID: 36043529 DOI: 10.1139/bcb-2021-0503] [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] [Indexed: 11/22/2022] Open
Abstract
The electrophoretic mobilities and catalytic rates of individual molecules of bovine intestinal alkaline phosphatase were determined in CHES and borate buffers of identical pH using a capillary electrophoresis based method. Both properties were found to be heterogeneous. In the presence of CHES, the mobility and rate were found to be -1.9 ± 0.2 × 10-9 m2 V-1 s-1 and 9.8 ± 7.4 × 104 min-1 (N = 38), respectively. In the presence of borate, the mobility and rate were found to be -6.9 ± 0.5 × 10-9 m2 V-1 s-1 and 2.0 ± 1.3 × 104 min-1 (N = 41), respectively. The means and variances for both properties were found to differ significantly between the two buffers. The difference in average mobility was attributed to an increase in negative charge caused by borate complexing with the carbohydrate moieties attached to the enzyme. The difference in variance was attributed to heterogeneous complexation with borate due to heterogeneity in the glycosylation. The differences in mean values for the catalytic rate were attributed to the inhibitory effect of borate and the difference in variance may suggest that the KI of this binding may also be heterogeneous.
Collapse
Affiliation(s)
- Douglas B Craig
- Chemistry Department, University of Winnipeg, Winnipeg, MB, Canada
| | - Simrat Malhi
- Chemistry Department, University of Winnipeg, Winnipeg, MB, Canada
| | - Basit Ahmad
- Chemistry Department, University of Winnipeg, Winnipeg, MB, Canada
| | | | - Ankoor Patel
- Chemistry Department, University of Winnipeg, Winnipeg, MB, Canada
| |
Collapse
|
5
|
Craig DB, Guimond MS. Analysis of cyanide using fluorogenic derivatization and capillary electrophoresis. Food Chem 2022; 370:131377. [PMID: 34788967 DOI: 10.1016/j.foodchem.2021.131377] [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: 07/06/2021] [Revised: 10/01/2021] [Accepted: 10/07/2021] [Indexed: 11/04/2022]
Abstract
Samples containing cyanide were incubated at 85 °C in the presence of the fluorogenic reagent 3-(2-furoyl)quinoline-2-carboxaldehyde (FQ) and glutamic acid, and analyzed by capillary electrophoresis utilizing post-separation laser-induced fluorescence detection in a sheath flow cuvette. The separation time on a 25 cm long capillary at 800 Vcm-1 was 3 min with the fluorescent product eluting at 107 s. Flushing of the capillary was not required between runs. Signal was proportional with cyanide concentration from 50 nM to 1.5 μM. LOD and LOQ were determined to be 26 and 87 nM respectively. As an application, free cyanide in five individual apple seeds was measured and found to range from 12 to 86 ng/mg, with a mean of 55 ± 32 ng/mg. As a means for the detection of amygdalin, cyanide was enzymatically produced from amygdalin using the enzymes β-glucosidase and mandelonitrile lyase. The cyanide was then reacted with FQ and injected onto the capillary. Amygdalin was detected at a concentration of 1 μM.
Collapse
Affiliation(s)
- Douglas B Craig
- Chemistry Department, University of Winnipeg, Winnipeg, Manitoba, Canada.
| | - Mitchell S Guimond
- Chemistry Department, University of Winnipeg, Winnipeg, Manitoba, Canada
| |
Collapse
|
6
|
Zhou K, Arslanturk S, Craig DB, Heath E, Draghici S. Discovery of primary prostate cancer biomarkers using cross cancer learning. Sci Rep 2021; 11:10433. [PMID: 34001952 PMCID: PMC8128891 DOI: 10.1038/s41598-021-89789-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 04/30/2021] [Indexed: 02/03/2023] Open
Abstract
Prostate cancer (PCa), the second leading cause of cancer death in American men, is a relatively slow-growing malignancy with multiple early treatment options. Yet, a significant number of low-risk PCa patients are over-diagnosed and over-treated with significant and long-term quality of life effects. Further, there is ever increasing evidence of metastasis and higher mortality when hormone-sensitive or castration-resistant PCa tumors are treated indistinctively. Hence, the critical need is to discover clinically-relevant and actionable PCa biomarkers by better understanding the biology of PCa. In this paper, we have discovered novel biomarkers of PCa tumors through cross-cancer learning by leveraging the pathological and molecular similarities in the DNA repair pathways of ovarian, prostate, and breast cancer tumors. Cross-cancer disease learning enriches the study population and identifies genetic/phenotypic commonalities that are important across diseases with pathological and molecular similarities. Our results show that ADIRF, SLC2A5, C3orf86, HSPA1B are among the most significant PCa biomarkers, while MTRNR2L1, EEPD1, TEPP and VN1R2 are jointly important biomarkers across prostate, breast and ovarian cancers. Our validation results have further shown that the discovered biomarkers can predict the disease state better than any randomly selected subset of differentially expressed prostate cancer genes.
Collapse
Affiliation(s)
- Kaiyue Zhou
- Department of Computer Science, Wayne State University, Detroit, 48201, USA
| | - Suzan Arslanturk
- Department of Computer Science, Wayne State University, Detroit, 48201, USA.
| | - Douglas B Craig
- Department of Oncology, Wayne State University, Detroit, 48201, USA
- Bioinformatics and Biostatistics Core, Barbara Ann Karmanos Cancer Institute, Detroit, 48201, USA
| | - Elisabeth Heath
- Department of Oncology, Wayne State University, Detroit, 48201, USA
- Molecular Therapeutics Program, Barbara Ann Karmanos Cancer Institute, Detroit, 48201, USA
| | - Sorin Draghici
- Department of Computer Science, Wayne State University, Detroit, 48201, USA
- Department of Obstetrics and Gynecology, Wayne State University, Detroit, 48201, USA
| |
Collapse
|
7
|
Purrington KS, Raychaudhuri S, Simon MS, Clark J, Ratliff V, Dyson G, Craig DB, Boerner JL, Beebe-Dimmer JL, Schwartz AG. Heritable Susceptibility to Breast Cancer among African-American Women in the Detroit Research on Cancer Survivors Study. Cancer Epidemiol Biomarkers Prev 2020; 29:2369-2375. [PMID: 32868316 DOI: 10.1158/1055-9965.epi-20-0564] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 07/16/2020] [Accepted: 08/26/2020] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND African-American women have high rates of breast cancer associated with hereditary features. However, no studies have reported the prevalence of inherited variation across all genes known to be breast cancer risk factors among African-American patients with breast cancer not selected for high-risk characteristics. METHODS We evaluated 182 African-American women diagnosed with invasive breast cancer in metropolitan Detroit via targeted capture and multiplex sequencing of 13 well-established breast cancer risk genes and five suggested breast cancer risk genes. RESULTS We identified 24 pathogenic variants in 23 women [12.6%; 95% confidence interval (CI), 8.2%-18.4%] and five genes (BRCA2, BRCA1, ATM, RAD50, CDH1). BRCA1 and BRCA2 accounted for 58.3% of all pathogenic variants. An additional six pathogenic variants were found in suggested breast cancer risk genes (MSH6, MUTYH, NF1, BRIP1). CONCLUSIONS The prevalence of germline pathogenic variants is relatively high among African-American patients with breast cancer unselected for high-risk characteristics across a broad spectrum of genes. IMPACT This study helps to define the genomic landscape of breast cancer susceptibility in African-American women who could benefit from enhanced surveillance and screening.
Collapse
Affiliation(s)
- Kristen S Purrington
- Department of Oncology, Wayne State University School of Medicine, Detroit, Michigan. .,Population Studies and Disparities Research Program, Barbara Ann Karmanos Cancer Institute, Detroit, Michigan
| | | | - Michael S Simon
- Department of Oncology, Wayne State University School of Medicine, Detroit, Michigan.,Population Studies and Disparities Research Program, Barbara Ann Karmanos Cancer Institute, Detroit, Michigan
| | - Julie Clark
- Department of Oncology, Wayne State University School of Medicine, Detroit, Michigan.,Molecular Therapeutics Program, Barbara Ann Karmanos Cancer Institute, Detroit, Michigan
| | - Valerie Ratliff
- Department of Oncology, Wayne State University School of Medicine, Detroit, Michigan
| | - Gregory Dyson
- Department of Oncology, Wayne State University School of Medicine, Detroit, Michigan.,Population Studies and Disparities Research Program, Barbara Ann Karmanos Cancer Institute, Detroit, Michigan.,Bioinformatics & Biostatistics Core, Barbara Ann Karmanos Cancer Institute, Detroit, Michigan
| | - Douglas B Craig
- Department of Oncology, Wayne State University School of Medicine, Detroit, Michigan.,Bioinformatics & Biostatistics Core, Barbara Ann Karmanos Cancer Institute, Detroit, Michigan
| | - Julie L Boerner
- Department of Oncology, Wayne State University School of Medicine, Detroit, Michigan.,Molecular Therapeutics Program, Barbara Ann Karmanos Cancer Institute, Detroit, Michigan
| | - Jennifer L Beebe-Dimmer
- Department of Oncology, Wayne State University School of Medicine, Detroit, Michigan.,Population Studies and Disparities Research Program, Barbara Ann Karmanos Cancer Institute, Detroit, Michigan
| | - Ann G Schwartz
- Department of Oncology, Wayne State University School of Medicine, Detroit, Michigan.,Population Studies and Disparities Research Program, Barbara Ann Karmanos Cancer Institute, Detroit, Michigan
| |
Collapse
|
8
|
Lischynski JR, Goltz DM, Craig DB. Measurement of phosphate in small samples using capillary electrophoresis with laser-induced luminescence detection. J LIQ CHROMATOGR R T 2019. [DOI: 10.1080/10826076.2018.1564326] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
| | - Douglas M. Goltz
- Department of Chemistry, University of Winnipeg, Winnipeg, Canada
| | - Douglas B. Craig
- Department of Chemistry, University of Winnipeg, Winnipeg, Canada
| |
Collapse
|
9
|
Dyson G, Farran B, Bolton S, Craig DB, Dombkowski A, Beebe-Dimmer JL, Powell IJ, Podgorski I, Heilbrun LK, Bock CH. The extrema of circulating miR-17 are identified as biomarkers for aggressive prostate cancer. Am J Cancer Res 2018; 8:2088-2095. [PMID: 30416858 PMCID: PMC6220145] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 06/03/2018] [Indexed: 06/09/2023] Open
Abstract
MicroRNAs (miRNAs) constitute short non-coding RNAs that can post-transcriptionally modulate the expression of many oncogenes and tumor suppressor genes engaged in key cellular processes. Deregulated serum miRNA signatures have been detected in various solid cancers including prostate cancer, suggesting that circulating miRNAs could function as non-invasive biomarkers of tumor emergence and progression. To determine whether serum miRNA expression levels are different between patients with aggressive and non-aggressive prostate cancer, we analyzed a panel of miRNAs from the blood of African American (AA) prostate cancer patients using a new recursive partitioning method that allows hypothesis testing of each split. We observed that both extrema of circulating miR-17, i.e. upregulation and downregulation, are associated with aggressive prostate cancer. A similar effect was observed in tumor samples from a separate dataset representing a different population of prostate cancer patients and in AA prostate cancer samples from the TCGA. The dual effect is consistent with the contradictory findings on the role of miR-17 in prostate cancer progression, whereby it controls important oncogenic and tumor-suppressive genes.
Collapse
Affiliation(s)
- Greg Dyson
- Karmanos Cancer Institute and Department of Oncology, Wayne State UniversityDetroit MI, USA
| | - Batoul Farran
- Karmanos Cancer Institute and Department of Oncology, Wayne State UniversityDetroit MI, USA
| | - Susan Bolton
- Karmanos Cancer Institute and Department of Oncology, Wayne State UniversityDetroit MI, USA
| | - Douglas B Craig
- Karmanos Cancer Institute and Department of Oncology, Wayne State UniversityDetroit MI, USA
| | - Alan Dombkowski
- Karmanos Cancer Institute and Department of Pediatrics, Wayne State UniversityDetroit MI, USA
| | | | - Isaac J Powell
- Karmanos Cancer Institute and Department of Urology, Wayne State UniversityDetroit MI, USA
| | - Izabela Podgorski
- Karmanos Cancer Institute and Department of Pharmacology, Wayne State UniversityDetroit MI, USA
| | - Lance K Heilbrun
- Karmanos Cancer Institute and Department of Oncology, Wayne State UniversityDetroit MI, USA
| | - Cathryn H Bock
- Karmanos Cancer Institute and Department of Oncology, Wayne State UniversityDetroit MI, USA
| |
Collapse
|
10
|
Dong L, Meng F, Wu L, Mitchell AV, Block CJ, Zhang B, Craig DB, Jang H, Chen W, Yang Q, Wu G. Cooperative oncogenic effect and cell signaling crosstalk of co‑occurring HER2 and mutant PIK3CA in mammary epithelial cells. Int J Oncol 2017; 51:1320-1330. [PMID: 28902361 PMCID: PMC5592866 DOI: 10.3892/ijo.2017.4108] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2017] [Accepted: 07/24/2017] [Indexed: 12/12/2022] Open
Abstract
Though incidence of PI3K oncogenic mutation is prominent in breast cancer (20-30%), pharmacological targeting of this signaling pathway alone has failed to provide meaningful clinical benefit. To better understand and address this problem, we conducted genome-wide analysis to study the association of mutant PI3K with other gene amplification events. One of the most significant copy number gain events associated with PIK3CA mutation was the region within chromosome 17 containing HER2To investigate the oncogenic effect and cell signaling regulation of co-occurring PIK3CA-H1047R and or HER2 gene, we generated cell models ectopically expressing mutant PIK3CA, HER2 or both genetic alterations. We observed that cells with both genetic alterations demonstrate increased aggressiveness and invasive capabilities than cells with either genetic change alone. Furthermore, we found that the combination of the HER2 inhibitor (CP-724714) and pan PI3K inhibitor (LY294002) is more potent than either inhibitor alone in terms of inhibition of cell proliferation and colony formation. Significantly, four cell signaling pathways were found in common for cells with HER2, mutant PIK3CA and cells with both genetic alterations through an Affymetric microarray analysis. Moreover, the cells with both genetic alterations acquired more significant replication stress as shown by enriched signaling pathways of cell cycle checkpoint control and DNA damage response signaling. Our study suggests co-occurrence of oncogenic HER2 and mutant PIK3CA cooperatively drives breast cancer progression. The cells with both genetic alterations obtain additional features of replication stress which could open new opportunity for cancer diagnostics and treatment.
Collapse
Affiliation(s)
- Lun Dong
- Barbara Ann Karmanos Cancer Institute, Department of Oncology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Fanyan Meng
- Barbara Ann Karmanos Cancer Institute, Department of Oncology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Ling Wu
- Barbara Ann Karmanos Cancer Institute, Department of Oncology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Allison V Mitchell
- Barbara Ann Karmanos Cancer Institute, Department of Oncology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - C James Block
- Barbara Ann Karmanos Cancer Institute, Department of Oncology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Bin Zhang
- Department of Genetics and Genomic Sciences, Icahn Institute of Genomics and Multiscale Biology, Icahn Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Douglas B Craig
- Barbara Ann Karmanos Cancer Institute, Department of Oncology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Hyejeong Jang
- Barbara Ann Karmanos Cancer Institute, Department of Oncology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Wei Chen
- Barbara Ann Karmanos Cancer Institute, Department of Oncology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Qifeng Yang
- Department of Breast Surgery, Qilu Hospital, Shandong University, Jinan, Shandong 250012, P.R. China
| | - Guojun Wu
- Barbara Ann Karmanos Cancer Institute, Department of Oncology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| |
Collapse
|
11
|
Craig DB, King SD, Reinfelds G, Henderson AR, Wood TE. Electrophoretic mobility, catalytic rate, and activation energy of catalysis of single molecules of the enzyme β-glucuronidase from Escherichia coli. Int J Biol Macromol 2017; 96:669-674. [DOI: 10.1016/j.ijbiomac.2016.12.034] [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] [Received: 03/25/2016] [Revised: 10/12/2016] [Accepted: 12/12/2016] [Indexed: 12/28/2022]
|
12
|
Crawford JJ, Hollett JW, Craig DB. Determination of the inhibitor dissociation constant of an individual unmodified enzyme molecule in free solution. Electrophoresis 2016; 37:2217-25. [PMID: 27271375 DOI: 10.1002/elps.201600201] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [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: 04/25/2016] [Revised: 05/12/2016] [Accepted: 05/26/2016] [Indexed: 11/11/2022]
Abstract
Single enzyme molecule assays on E. coli β-galactosidase were performed using a capillary electrophoresis-based method. Three types of assays were performed. The catalytic rate of 20 individual molecules was assayed in duplicate in the presence of 50 μM substrate. The ratio of rates for the second incubation relative to the first was 0.96 ± 0.03, showing the reproducibility of the method. In the second assay, the rates were determined in the absence and presence of 210 μM L-ribose, a competitive inhibitor. The ratio of the rate in the presence of inhibitor to that in its absence for 19 individual molecules was 0.44 ± 0.23. This large relative standard deviation suggests that each individual enzyme molecule was affected to a different extent by the presence of the inhibitor, which is consistent with KI being heterogeneous. To estimate KI for individual molecules, a third assay was performed. Each molecule was incubated in the presence of 30 and 50 μM substrate and then in the presence of 50 μM substrate plus 210 μM inhibitor. Comparison of the rates in the two substrate concentrations allowed for the determination of the individual Km of each molecule. From this value and the difference in rates in the presence and absence of inhibitor, the individual molecule KI values were determined. This value was found to differ between individual molecules and was found to increase with an increase in Km . Modeling showed that a heterogeneity in KI results in an alteration in the Michaelis-Menten curve for a population of enzymes in the presence of a competitive inhibitor.
Collapse
Affiliation(s)
| | | | - Douglas B Craig
- Chemistry Department, University of Winnipeg, Winnipeg, Canada
| |
Collapse
|
13
|
Abstract
Single β-galactosidase molecule assays were performed using a capillary electrophoresis based protocol, employing post-column laser-induced fluorescence detection. In a first set of experiments, the distribution of single β-galactosidase molecule catalytic rates and electrophoretic mobilities were determined from lysates of Escherichia coli strains containing deletions for different heat shock proteins and grown under normal and heat shock conditions. There was no clear observed pattern of effect of heat shock protein expression on these distributions. In a second set of experiments, individual enzyme molecule catalytic rates were determined at 21 °C before and after 2 sequential brief periods of incubation at 50, 28, and 10 °C. The brief incubations at 50 °C caused a change in the enzyme molecules resulting in a different catalytic rate. Any given molecule was just as likely to show an increase in rate as a decrease, resulting in no significant difference in the average rate of the population. The average change in individual molecule rate was dependent upon the temperature of the brief incubation period, with a lesser average change occurring at 28 °C and negligible change at 10 °C. A third set of experiments was similar to that of the second with the exception that it was electrophoretic mobility that was considered. This provided a similar result. Incubation at higher temperature resulted in a change in electrophoretic mobility. The probability of an individual molecules switching to a higher mobility was approximately equal to that of switching to a lower mobility, resulting in no net average change in the population. The magnitude of the changes in electrophoretic mobilities suggest that the associated conformational changes are subtle.
Collapse
Affiliation(s)
- Jeremie J Crawford
- a Department of Chemistry, 360 Parker Building, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Frannie Itzkow
- b Department of Chemistry, 599 Portage Avenue, University of Winnipeg, Winnipeg, MB R3B 2G3, Canada
| | - Joanna MacLean
- b Department of Chemistry, 599 Portage Avenue, University of Winnipeg, Winnipeg, MB R3B 2G3, Canada
| | - Douglas B Craig
- b Department of Chemistry, 599 Portage Avenue, University of Winnipeg, Winnipeg, MB R3B 2G3, Canada
| |
Collapse
|
14
|
Craig DB, Hanlon-Dearman F, Beaudry S, Shek K, King SD. Comparison of the single molecule activity distributions of recombinant and non-recombinant bovine intestinal alkaline phosphatase. Protein Expr Purif 2015; 114:95-8. [DOI: 10.1016/j.pep.2015.06.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Revised: 05/29/2015] [Accepted: 06/22/2015] [Indexed: 10/23/2022]
|
15
|
Craig DB, Reinfelds G, Henderson A. 12-Channel Peltier array temperature control unit for single molecule enzymology studies using capillary electrophoresis. Electrophoresis 2014; 35:2408-11. [PMID: 24616017 DOI: 10.1002/elps.201300526] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [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: 10/29/2013] [Revised: 02/06/2014] [Accepted: 02/11/2014] [Indexed: 11/07/2022]
Abstract
Capillary electrophoresis has been used to demonstrate that individual molecules of a given enzyme support different catalytic rates. In order to determine how rate varies with temperature, and determine activation energies for individual β-galactosidase molecules, a 12-channel Peltier array temperature control device was constructed where the temperature of each cell was separately controlled. This array was used to control the temperature of the central 30 cm of a 50 cm long capillary, producing a temperature gradient along its length. Continuous flow single β-galactosidase molecule assays were performed allowing measurement of the catalytic rates at different temperatures. Arrhenius plots were produced and the distribution of activation energies for individual β-galactosidase molecules was found to be 56 ± 10 kJ/mol with a range of 34-72 kJ/mol.
Collapse
Affiliation(s)
- Douglas B Craig
- Chemistry Department, University of Winnipeg, Winnipeg, MB, Canada
| | | | | |
Collapse
|
16
|
Craig DB, Dombkowski AA. Disulfide by Design 2.0: a web-based tool for disulfide engineering in proteins. BMC Bioinformatics 2013; 14:346. [PMID: 24289175 PMCID: PMC3898251 DOI: 10.1186/1471-2105-14-346] [Citation(s) in RCA: 292] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 11/24/2013] [Indexed: 01/14/2023] Open
Abstract
Background Disulfide engineering is an important biotechnological tool that has advanced a wide range of research. The introduction of novel disulfide bonds into proteins has been used extensively to improve protein stability, modify functional characteristics, and to assist in the study of protein dynamics. Successful use of this technology is greatly enhanced by software that can predict pairs of residues that will likely form a disulfide bond if mutated to cysteines. Results We had previously developed and distributed software for this purpose: Disulfide by Design (DbD). The original DbD program has been widely used; however, it has a number of limitations including a Windows platform dependency. Here, we introduce Disulfide by Design 2.0 (DbD2), a web-based, platform-independent application that significantly extends functionality, visualization, and analysis capabilities beyond the original program. Among the enhancements to the software is the ability to analyze the B-factor of protein regions involved in predicted disulfide bonds. Importantly, this feature facilitates the identification of potential disulfides that are not only likely to form but are also expected to provide improved thermal stability to the protein. Conclusions DbD2 provides platform-independent access and significantly extends the original functionality of DbD. A web server hosting DbD2 is provided at http://cptweb.cpt.wayne.edu/DbD2/.
Collapse
Affiliation(s)
| | - Alan A Dombkowski
- Department of Pediatrics, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
| |
Collapse
|
17
|
Abstract
Improving the stability of proteins is an important goal in many biomedical and industrial applications. A logical approach is to emulate stabilizing molecular interactions found in nature. Disulfide bonds are covalent interactions that provide substantial stability to many proteins and conform to well-defined geometric conformations, thus making them appealing candidates in protein engineering efforts. Disulfide engineering is the directed design of novel disulfide bonds into target proteins. This important biotechnological tool has achieved considerable success in a wide range of applications, yet the rules that govern the stabilizing effects of disulfide bonds are not fully characterized. Contrary to expectations, many designed disulfide bonds have resulted in decreased stability of the modified protein. We review progress in disulfide engineering, with an emphasis on the issue of stability and computational methods that facilitate engineering efforts.
Collapse
Affiliation(s)
- Alan A Dombkowski
- Carman and Ann Adams Department of Pediatrics, Wayne State University School of Medicine, Detroit, MI 48201, USA.
| | - Kazi Zakia Sultana
- Department of Computer Science & Engineering, Chittagong University of Engineering & Technology, Chittagong 4349, Bangladesh
| | - Douglas B Craig
- Carman and Ann Adams Department of Pediatrics, Wayne State University School of Medicine, Detroit, MI 48201, USA
| |
Collapse
|
18
|
Craig DB, Bayaraa B, Lee D, Charleton J. EFFECT OF INDUCTION TEMPERATURE AND PARTIAL THERMAL DENATURATION ON THE CATALYTIC AND ELECTROPHORETIC HETEROGENEITY OF β-GALACTOSIDASE FROM TWO ESCHERICHIA COLI STRAINS. J LIQ CHROMATOGR R T 2013. [DOI: 10.1080/10826076.2012.731672] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Douglas B Craig
- a Chemistry Department , University of Winnipeg , Winnipeg , Manitoba , Canada
| | - Bayasgalan Bayaraa
- a Chemistry Department , University of Winnipeg , Winnipeg , Manitoba , Canada
| | - Dorice Lee
- a Chemistry Department , University of Winnipeg , Winnipeg , Manitoba , Canada
| | - Justin Charleton
- a Chemistry Department , University of Winnipeg , Winnipeg , Manitoba , Canada
| |
Collapse
|
19
|
Goltz DM, Ahmadi S, Absalan G, Craig DB. SEPARATION OF HISTORICAL DYES USING CAPILLARY ELECTROPHORESIS WITH LASER-INDUCED FLUORESCENCE DETECTION. J LIQ CHROMATOGR R T 2012. [DOI: 10.1080/10826076.2011.627620] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Douglas M. Goltz
- a Centre for Scientific and Curatorial Analysis of Painting Elements (C-SCAPE), Department of Chemistry , University of Winnipeg , Winnipeg , Manitoba , Canada
- b Department of Chemistry , University of Manitoba , Winnipeg , Manitoba , Canada
| | - Shokoufeh Ahmadi
- b Department of Chemistry , University of Manitoba , Winnipeg , Manitoba , Canada
| | | | - Douglas B. Craig
- a Centre for Scientific and Curatorial Analysis of Painting Elements (C-SCAPE), Department of Chemistry , University of Winnipeg , Winnipeg , Manitoba , Canada
| |
Collapse
|
20
|
Craig DB, Schwab T, Sterner R. Random mutagenesis suggests that sequence errors are not a major cause of variation in the activity of individual molecules of β-galactosidase. Biochem Cell Biol 2012; 90:540-7. [DOI: 10.1139/o2012-006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Wild-type Escherichia coli lacZ was subjected to error-prone PCR to generate two plasmid-encoded gene libraries containing approximately 2.6 (SD 1.9) nucleotide exchanges resulting in 1.8 (SD 1.4) amino-acid substitutions. The libraries were used, along with a plasmid containing wild-type lacZ, to transform E. coli lacking genomic lacZ. Cells expressing functional β-galactosidase were identified by blue/white screening. Cell lysates containing the populations of heterogeneously mutagenized β-galactosidase were subjected to single molecule assays using a capillary electrophoresis laser-induced fluorescence-based protocol. There was no significant difference in the average catalytic rate between the random mutagenized and wild-type enzyme populations. Furthermore, there was no clear pattern between error rates and the variances in the population catalytic rates. This suggests that random sequence errors are not a substantial source of the catalytic heterogeneity of this enzyme.
Collapse
Affiliation(s)
- Douglas B. Craig
- Chemistry Department, University of Winnipeg, 515 Portage Avenue, Winnipeg, MB, Canada
| | - Thomas Schwab
- University of Regensburg, Institute of Biophysics and Physical Biochemistry, Universitätsstraße 31, D-93053, Regensburg, Germany
| | - Reinhard Sterner
- University of Regensburg, Institute of Biophysics and Physical Biochemistry, Universitätsstraße 31, D-93053, Regensburg, Germany
| |
Collapse
|
21
|
Craig DB, Kannan S, Dombkowski AA. Augmented annotation and orthologue analysis for Oryctolagus cuniculus: Better Bunny. BMC Bioinformatics 2012; 13:84. [PMID: 22568790 PMCID: PMC3424829 DOI: 10.1186/1471-2105-13-84] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Accepted: 04/25/2012] [Indexed: 11/27/2022] Open
Abstract
Background The rabbit is an important model organism used in a wide range of biomedical research. However, the rabbit genome is still sparsely annotated, thus prohibiting extensive functional analysis of gene sets derived from whole-genome experiments. We developed a web-based application that provides augmented annotation and orthologue analysis for rabbit genes. Importantly, the application allows comprehensive functional analysis through the use of orthologous relationships. Results Using data extracted from several public bioinformatics repositories we created Better Bunny, a database and query tool that extensively augments the available functional annotation for rabbit genes. Using the complete set of target genes from a commercial rabbit gene expression microarray as our benchmark, we are able to obtain functional information for 88 % of the genes on the microarray. Previously, functional information was available for fewer than 10 % of the rabbit genes. Conclusions We have developed a freely available, web-accessible bioinformatics tool that enables investigators to quickly and easily perform extensive functional analysis of rabbit genes (http://cptweb.cpt.wayne.edu). The software application fills a critical void for a wide range of biomedical research that relies on the rabbit model and requires characterization of biological function for large sets of genes.
Collapse
Affiliation(s)
- Douglas B Craig
- Department of Pediatrics, Wayne State University School of Medicine, Detroit, MI, USA
| | | | | |
Collapse
|
22
|
Craig DB, Morris TT, Ong-Justiniano CMQ. Measurement of the Activity of Individual Subunits of Single Molecules of the Tetrameric Enzyme β-Galactosidase. Anal Chem 2012; 84:4598-602. [DOI: 10.1021/ac300777u] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Douglas B. Craig
- Chemistry Department, University of Winnipeg, Winnipeg, Manitoba, Canada
| | - Thomas T. Morris
- Chemistry Department, University of Winnipeg, Winnipeg, Manitoba, Canada
| | | |
Collapse
|
23
|
Affiliation(s)
- Douglas B Craig
- Chemistry Department, University of Winnipeg, 515 Portage Avenue, Winnipeg,
Manitoba, Canada R3B 2E9
| | - Linden N Chase
- Chemistry Department, University of Winnipeg, 515 Portage Avenue, Winnipeg,
Manitoba, Canada R3B 2E9
| |
Collapse
|
24
|
Craig DB, Eggertson MJ, Chikamatsu M, Horwood CA. Single Molecule Assay ofEscherichia coliβ-Galactosidase Using Two Competing Substrates Simultaneously, DDAO-β-D-Galactoside and Resorufin-β-D-Galactoside. ANAL LETT 2011. [DOI: 10.1080/00032719.2010.526264] [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: 10/18/2022]
|
25
|
|
26
|
Dombkowski AA, Sultana Z, Craig DB, Jamil H. In silico analysis of combinatorial microRNA activity reveals target genes and pathways associated with breast cancer metastasis. Cancer Inform 2011; 10:13-29. [PMID: 21552493 PMCID: PMC3085424 DOI: 10.4137/cin.s6631] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [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] [Indexed: 12/18/2022] Open
Abstract
This is an open access article. Unrestricted non-commercial use is permitted provided the original work is properly cited. Aberrant microRNA activity has been reported in many diseases, and studies often find numerous microRNAs concurrently dysregulated. Most target genes have binding sites for multiple microRNAs, and mounting evidence indicates that it is important to consider their combinatorial effect on target gene repression. A recent study associated the coincident loss of expression of six microRNAs with metastatic potential in breast cancer. Here, we used a new computational method, miR-AT!, to investigate combinatorial activity among this group of microRNAs. We found that the set of transcripts having multiple target sites for these microRNAs was significantly enriched with genes involved in cellular processes commonly perturbed in metastatic tumors: cell cycle regulation, cytoskeleton organization, and cell adhesion. Network analysis revealed numerous target genes upstream of cyclin D1 and c-Myc, indicating that the collective loss of the six microRNAs may have a focal effect on these two key regulatory nodes. A number of genes previously implicated in cancer metastasis are among the predicted combinatorial targets, including TGFB1, ARPC3, and RANKL. In summary, our analysis reveals extensive combinatorial interactions that have notable implications for their potential role in breast cancer metastasis and in therapeutic development.
Collapse
Affiliation(s)
- Alan A Dombkowski
- Division of Clinical Pharmacology and Toxicology, Department of Pediatrics, Wayne State University School of Medicine, Detroit, MI, USA.
| | | | | | | |
Collapse
|
27
|
Craig DB, Haslam AM, Coombs JM, Nichols ER. Kinetic studies of unmodified individual Escherichia coli β-galactosidase molecules in free solution. Biochem Cell Biol 2010; 88:451-8. [DOI: 10.1139/o09-120] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Assays were performed on individual Escherichia coli β-galactosidase molecules at 2 different concentrations of the substrate DDAO-β-d-galactoside using a free zone capillary electrophoresis–based protocol with an in-laboratory–constructed instrument utilizing laser-induced fluorescence detection. In a typical run, 2 enzyme molecules were injected into the capillary. They were separated from each other by a brief period of electrophoresis and incubated on the capillary in the presence of the substrate. They were then mobilized on the capillary into a zone of substrate at a different concentration, re-incubated, and the product peaks mobilized past the detector . The relative change in activity as the concentration was increased differed between molecules, suggesting differences in Km. In a different experiment, the capillary was filled with on average 13 enzyme molecules per run, incubated, and the activities of the individual molecules determined. The shapes of the distribution curves of single molecule activities obtained at different concentrations of the substrate resorufin-β-d-galactoside were indistinguishable, suggesting a homogeneous Km. To explain why individual enzyme molecules behaved as if they were heterogeneous with respect to Km but the population behaved as if it were homogeneous, theoretical Michaelis–Menten curves were constructed. The curves for populations with heterogeneous Km values were found to be indistinguishable from that of a homogeneous population.
Collapse
Affiliation(s)
- Douglas B. Craig
- Chemistry Department, University of Winnipeg, 515 Portage Ave., Winnipeg, MB, R3B 2E9, Canada
| | - Allison M. Haslam
- Chemistry Department, University of Winnipeg, 515 Portage Ave., Winnipeg, MB, R3B 2E9, Canada
| | - Jennifer M.L. Coombs
- Chemistry Department, University of Winnipeg, 515 Portage Ave., Winnipeg, MB, R3B 2E9, Canada
| | - Ellert R. Nichols
- Chemistry Department, University of Winnipeg, 515 Portage Ave., Winnipeg, MB, R3B 2E9, Canada
| |
Collapse
|
28
|
Nichols ER, Shadabi E, Craig DB. Effect of alteration of translation error rate on enzyme microheterogeneity as assessed by variation in single molecule electrophoretic mobility and catalytic activity. Biochem Cell Biol 2009; 87:517-29. [DOI: 10.1139/o09-010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The role of translation error for Escherichia coli individual β-galactosidase molecule catalytic and electrophoretic heterogeneity was investigated using CE-LIF. An E. coli rpsL mutant with a hyperaccurate translation phenotype produced enzyme molecules that exhibited significantly less catalytic heterogeneity but no reduction of electrophoretic heterogeneity. Enzyme expressed with streptomycin-induced translation error had increased thermolability, lower activity, and no significant change to catalytic or electrophoretic heterogeneity. Modeling of the electrophoretic behaviour of β-galactosidase suggested that variation of the hydrodynamic radius may be the most significant contributor to electrophoretic heterogeneity.
Collapse
Affiliation(s)
- Ellert R. Nichols
- Chemistry Department, University of Winnipeg, 515 Portage Ave, Winnipeg, MB R3B 2E9, Canada
- Registered as a graduate student at the Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Elnaz Shadabi
- Chemistry Department, University of Winnipeg, 515 Portage Ave, Winnipeg, MB R3B 2E9, Canada
- Registered as a graduate student at the Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Douglas B. Craig
- Chemistry Department, University of Winnipeg, 515 Portage Ave, Winnipeg, MB R3B 2E9, Canada
- Registered as a graduate student at the Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| |
Collapse
|
29
|
Craig DB, Nichols ER. Continuous flow assay for the simultaneous measurement of the electrophoretic mobility, catalytic activity and its variation over time of individual molecules of Escherichia coli beta-galactosidase. Electrophoresis 2009; 29:4298-303. [PMID: 19016504 DOI: 10.1002/elps.200800482] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A CE-LIF detection-based assay was developed for the study of individual molecules of Escherichia coli beta-galactosidase. The assay allows for the simultaneous measurement of the electrophoretic mobility, catalytic activity and the variation in activity over time of individual enzyme molecules. In addition to showing the microheterogeneity of the enzyme molecules with respect to mobility and activity, it was demonstrated that at elevated temperatures the enzyme activity fluctuates over time. Incubation at varying temperatures showed that individual beta-galactosidase molecules exhibit differences in their change in activity upon a change in incubation temperature. Incubation at one temperature, followed by an incubation at an elevated temperature and subsequent incubation back at the initial lower temperature caused the molecules to have a different activity than they had initially. Additionally, thermal denaturation was found to cause a rapid and complete loss of activity.
Collapse
Affiliation(s)
- Douglas B Craig
- Chemistry Department, University of Winnipeg, Winnipeg, Manitoba, Canada.
| | | |
Collapse
|
30
|
Nichols ER, Craig DB. Measurement of the differences in electrophoretic mobilities of individual molecules ofE. coliβ-galactosidase provides insight into structural differences which underlie enzyme microheterogeneity. Electrophoresis 2008; 29:4257-69. [DOI: 10.1002/elps.200800060] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
31
|
|
32
|
Nichols ER, Gavina JMA, McLeod RG, Craig DB. Single Molecule Assays of β-Galactosidase from Two Wild-type Strains of E. coli: Effects of Protease Inhibitors on Microheterogeneity and Different Relative Activities with Differing Substrates. Protein J 2007; 26:95-105. [PMID: 17253128 DOI: 10.1007/s10930-006-9050-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Beta-galactosidase was induced in E. coli wild type strains ATCC 8677 and 35321 in the presence of various protease inhibitors. Single enzyme molecule assays were performed using a capillary electrophoresis based protocol. The presence of the protease inhibitors had a minimal effect on the average and distribution of single molecule activities. Two novel capillary electrophoresis based single enzyme molecule assays for beta-galactosidase were developed using DDAO-beta-D-galactopyranoside and fluorescein-beta-D-digalactopyranoside as substrates. Double incubations were performed on individual enzyme molecules to demonstrate the reproducibility of the assays. Assays performed on beta-galactosidase from strains 8677 and 35321 demonstrated that the relative activities of the enzyme for the different substrates differed between the strains. Sequencing showed that these two strains differ in their primary sequence by a single amino acid substitution in position 280, which is in the region of the active site.
Collapse
Affiliation(s)
- Ellert R Nichols
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB, Canada
| | | | | | | |
Collapse
|
33
|
Craig DB, Wetzl BK, Duerkop A, Wolfbeis OS. Determination of picomolar concentrations of proteins using novel amino reactive chameleon labels and capillary electrophoresis laser-induced fluorescence detection. Electrophoresis 2005; 26:2208-13. [PMID: 15880625 DOI: 10.1002/elps.200410332] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Py-1 and Py-6 are novel amino-reactive fluorescent reagents. The names given to them reflect that they consist of a pyrylium group attached to small aromatic moieties. Upon reaction with a primary amine there is a large spectral shift in the reagent, rendering them effectively fluorogenic. In this study, these reagents were used to label a test protein, (human serum albumin), and the sample was analyzed by capillary electrophoresis and laser-induced fluorescence detection. Detection limits after a 60 min labeling reaction at 22 degrees C (Py-1) and 50 degrees C (Py-6) were 6.5 ng/mL (98 pM) for Py-1 and 1.2 ng/mL (18 pM) for Py-6. Separation of immunoglobulin G (IgG), human serum albumin, lipase, and myoglobin after labeling with Py-6 were performed. The method was further modified to make it amenable to automation. Unlike many other amino reactive reagents used to label protein amino groups, reaction with Py-1 and Py-6 do not alter the charge of the protein and the advantage of this with respect to electrophoretic separations is discussed.
Collapse
Affiliation(s)
- Douglas B Craig
- Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, Regensburg, Germany.
| | | | | | | |
Collapse
|
34
|
Affiliation(s)
- Bianca K Wetzl
- Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, 93040 Regensburg, Germany
| | | | | | | |
Collapse
|
35
|
Wetzl BK, Yarmoluk SM, Craig DB, Wolfbeis OS. Ein Chamäleon-Marker zur Anfärbung und quantitativen Bestimmung von Proteinen. Angew Chem Int Ed Engl 2004. [DOI: 10.1002/ange.200460508] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
36
|
Craig DB, Nachtigall JT, Ash HL, Shoemaker GK, Dyck AC, Wawrykow TMJ, Gudbjartson HL. Differences in the average single molecule activities of E. coli beta-galactosidase: effect of source, enzyme molecule age and temperature of induction. J Protein Chem 2003; 22:555-61. [PMID: 14703989 DOI: 10.1023/b:jopc.0000005505.73032.16] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Using a capillary electrophoresis-based method, single enzyme molecule assays were performed on E. coli beta-galactosidase from three different sets of samples. The first set consisted of lysates of induced cells from five different strains of the bacteria, as well as two different commercial preparations of the enzyme. These samples were found to have substantially different distributions of single molecule activities. For the second set of samples, beta-galactosidase expression was induced for 1.5 hr, followed by further incubation where expression was repressed. Assays were performed on the lysates of the preinduction and on the lysates from aliquots taken set times postinduction. The recently induced enzyme had a 25% higher average single molecule activity than the basally expressed enzyme. This average activity returned to the basal value 3.5 hr postinduction and remained unchanged thereafter. Finally, beta-galactosidase was induced at 26 and 42 degrees C. The enzyme was assayed before and after partial thermal denaturation. The samples were found to be indistinguishable with respect to their average single molecule activities.
Collapse
Affiliation(s)
- Douglas B Craig
- Chemistry Department, University of Winnipeg, Winnipeg, MB, Canada R3B 2E9.
| | | | | | | | | | | | | |
Collapse
|
37
|
Shoemaker GK, Juers DH, Coombs JML, Matthews BW, Craig DB. Crystallization of beta-galactosidase does not reduce the range of activity of individual molecules. Biochemistry 2003; 42:1707-10. [PMID: 12578385 DOI: 10.1021/bi0204138] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [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] [Indexed: 11/28/2022]
Abstract
By use of a capillary electrophoresis-based procedure, it is possible to measure the activity of individual molecules of beta-galactosidase. Molecules from the crystallized enzyme as well as the original enzyme preparation used to grow the crystals both displayed a range of activity of 20-fold or greater. beta-Galactosidase molecules obtained from two different crystals had indistinguishable activity distributions of 31,600 +/- 1100 and 31,800 +/- 1100 reactions min(-1) (enzyme molecule)(-1). This activity was found to be significantly different from that of the enzyme used to grow the crystals, which showed an activity distribution of 38,500 +/- 900 reactions min(-1) (enzyme molecule)(-1).
Collapse
Affiliation(s)
- Glen K Shoemaker
- Chemistry Department, University of Winnipeg, Winnipeg, Manitoba, R3B 2E9, Canada
| | | | | | | | | |
Collapse
|
38
|
Abstract
Thermus thermophilus cells were grown at 70 degrees C, lysed and the lysate subjected to single molecule alkaline phosphatase assays, using a capillary electrophoresis laser-induced fluorescence detection-based method. The enzyme was found to be heterogeneous with respect to catalytic rate when assayed at room temperature. Turnover numbers ranged 12-fold, with an average of 400 +/- 200 reactions/min for the 80 molecules assayed.
Collapse
Affiliation(s)
- Ashley C Dyck
- Department of Chemistry, University of Winnipeg, Winnipeg, MB R3B 2E9, Canada
| | | |
Collapse
|
39
|
Tuominen EK, Zhu K, Wallace CJ, Clark-Lewis I, Craig DB, Rytomaa M, Kinnunen PK. ATP induces a conformational change in lipid-bound cytochrome c. J Biol Chem 2001; 276:19356-62. [PMID: 11279142 DOI: 10.1074/jbc.m100853200] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Resonance energy transfer studies using a pyrene-labeled phospholipid derivative 1-palmitoyl-2-[10-(pyren-1-yl)decanoyl]-sn-glycero-3-phosphoglycerol (donor) and the heme (acceptor) of cytochrome c (cyt c) have indicated that ATP causes changes in the conformation of the lipid-bound protein (Rytömaa, M., Mustonen, P., and Kinnunen, P. K. J. (1992) J. Biol. Chem. 267, 22243-22248). Accordingly, after binding cyt c via its so called C-site to neat phosphatidylglycerol liposomes (mole fraction of PG = 1.0) has commenced, further quenching of donor fluorescence is caused by ATP, saturating at 2 mm nucleotide. ATP-induced conformational changes in liposome-associated cyt c could be directly demonstrated by CD in the Soret band region (380-460 nm). The latter data were further supported by time-resolved spectroscopy using the fluorescent cyt c analog with a Zn(2+)-substituted heme moiety. A high affinity ATP-binding site has been demonstrated in cyt c (Craig, D. B., and Wallace, C. J. A. (1993) Protein Sci. 2, 966-976) that is compromised by replacing the invariant Arg(91) to norleucine. Although no major effects on conformation and function of cyt c were concluded due to the modification, a significantly reduced effect by ATP on the lipid-bound [Nle(91)]cyt c was evident, implying that this modulation is mediated via the Arg(91)-containing binding site.
Collapse
Affiliation(s)
- E K Tuominen
- Helsinki Biophysics and Biomembrane Group, Department of Medical Chemistry, Institute of Biomedicine, P.O. Box B8 (Siltavuorenpenger 10 A), University of Helsinki, FIN-00014 Helsinki, Finland
| | | | | | | | | | | | | |
Collapse
|
40
|
Abstract
Commercially obtained E. coli beta-galactosidase was stored at 25 degrees C in buffer containing 1 mM MgCl2 and in buffer containing no added MgCl2. Samples were removed at set times and the activity of individual enzyme molecules assayed. When stored in the presence of 1 mM magnesium, the number of active molecules did not change over a 2.5-h period. When stored in the absence of added MgCl2, over half the enzyme molecules became inactive within the first hour. However, those molecules which retained activity remained active for the duration of the experiment. This indicates that there may exist two populations of E. coli beta-galactosidase, one which requires storage in the presence of the higher concentration of Mg2+ in order to remain active. There was no observed correlation between this requirement for magnesium and reaction rate. Additionally, the presence of the 1 mM MgCl2 was found to decrease the average activity of the beta-galactosidase molecules under the conditions employed.
Collapse
Affiliation(s)
- D B Craig
- Department of Chemistry, University of Winnipeg, MB Canada.
| | | | | |
Collapse
|
41
|
Abstract
OBJECTIVE The objective of this study was to compare the activities of individual molecules of induced and basally expressed Escherichia coli beta-galactosidase. BACKGROUND DATA Single-molecule assays of enzymes have determined that individual molecules are not identical. They differ with respect to catalytic rate. The structural cause and cellular role of this microheterogeneity is as yet unknown. METHODS E. coli were grown and induced to produce beta-galactosidase by treatment with isopropyl-beta-D-thiogalactopyranoside. Cells were lysed and the beta-galactosidase assayed with capillary electrophoresis instrumentation utilizing post-column, laser-induced fluorescence detection. The enzyme obtained from treated cells were compared to that from untreated cells. RESULTS The activity of newly induced beta-galactosidase was found to be approximately 20% greater than that of the basally expressed enzyme. This measured difference is statistically significant. CONCLUSIONS Production of beta-galactosidase in E. coli under differing conditions results in differences in the activities of the individual enzyme molecules.
Collapse
Affiliation(s)
- D B Craig
- Chemistry Department, University of Winnipeg, Manitoba, Canada.
| | | |
Collapse
|
42
|
Abstract
A laser-induced fluorescence detector for liquid chromatography was developed. This detector was assessed by utilizing it in conjunction with gel filtration chromatography. Using the 488 nm line of an argon ion laser for excitation and monitoring the emitted fluorescence centering at 535 nm, the limit of detection of fluorescein was 580 fM. Bovine serum albumin labeled with fluorescein was detected at a concentration of 500 fM.
Collapse
Affiliation(s)
- M J Eggertson
- Department of Chemistry, University of Winnipeg, MB, Canada
| | | |
Collapse
|
43
|
Abstract
beta-Galactosidase was incubated for 60 min with the fluorogenic substrate resorufin-beta-D-galactopyranoside, which is converted by the action of the enzyme into resorufin and galactose. A 160 pL aliquot of reaction mixture was analyzed by capillary electrophoresis utilizing laser-induced fluorescence detection. Based on the detection of the resorufin formed, the limit of detection of beta-galactosidase was 1.5 x 10(-15) M or 900 molecules of enzyme in a 1 microL sample.
Collapse
Affiliation(s)
- M J Eggertson
- Department of Chemistry, University of Winnipeg, 515 Portage Avenue, Winnipeg, Manitoba, Canada R3B 2E9
| | | |
Collapse
|
44
|
|
45
|
|
46
|
Craig DB, Wong JC, Polakowski R, Dovichi NJ. General protease assay method coupling solid-phase substrate extraction and capillary electrophoresis. Anal Chem 1998; 70:3824-7. [PMID: 9751024 DOI: 10.1021/ac9801061] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Capillary electrophoresis with laser-induced fluorescence detection was used to develop a universal, highly specific protease assay. In this method, a peptide, biotinylated at the N-terminus, is labeled with fluorescein at a lysine residue near the C-terminus. Impurities are removed from the fluorescence labeling mixture by solid-phase extraction of the substrate on immobilized streptavidin, followed by extensive washing. The purified fluorescent substrate is dissociated from the streptavidin and incubated with the protease. The peptide sequence between the biotin and fluorescent label contains the cleavage sequence of the protease of interest. After cleavage, the fluorescent product does not contain a biotin group. A second solid-phase extraction is used to remove unreacted substrate to dramatically lower the background signal. The product is detected by capillary electrophoresis, which provides powerful discrimination against products generated by nonspecific proteases. With chymotrypsin as a test protease, product was detected with as little as 10 pg/mL (4.6 x 10(-13) M) chymotrypsin, or 5 amol of enzyme in the 10-microL sample volume.
Collapse
Affiliation(s)
- D B Craig
- Department of Chemistry, University of Alberta, Edmonton, Canada
| | | | | | | |
Collapse
|
47
|
|
48
|
Craig DB, Polakowski RM, Arriaga E, Wong JC, Ahmadzadeh H, Stathakis C, Dovichi NJ. Sodium dodecyl sulfate-capillary electrophoresis of proteins in a sieving matrix utilizing two-spectral channel laser-induced fluorescence detection. Electrophoresis 1998; 19:2175-8. [PMID: 9761200 DOI: 10.1002/elps.1150191222] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We report a method for protein labeling, separation by capillary electrophoresis in a polymer sieving matrix, and detection by laser-induced fluorescence. Different dyes are used to label standard and sample proteins. A two-spectral channel detector resolves fluorescence from the sample and standards. Comparison of the migration time of the sample and standards permits the precise determination of molecular weight, irrespective of variations in run-to-run migration times.
Collapse
Affiliation(s)
- D B Craig
- Department of Chemistry, University of Alberta, Edmonton, Canada
| | | | | | | | | | | | | |
Collapse
|
49
|
|
50
|
Abstract
We present a case of a patient who is HIV positive and developed both thrombotic thrombocytopenia purpura and visceral Kaposi's sarcoma (KS) with hemorrhage. This case presents a difficult management problem in that the patient's bleeding originated from KS lesions and did not quickly abate with plasmapheresis therapy despite both clinical and laboratory improvement after 2-4 days. Chemotherapy was initiated on day 13 and the patient's condition improved markedly afterward. We believe the addition of chemotherapy to plasmapheresis hastened the improvement of our patient's thrombotic thrombocytopenic purpura (TTP) and KS-related bleeding. Therefore, under similar conditions, we recommend combining plasmapheresis and chemotherapy at the onset of therapy.
Collapse
Affiliation(s)
- R A Avery
- Hematology Oncology Service, Eisenhower Army Medical Center, Fort Gordon, Georgia 30905, USA
| | | | | |
Collapse
|