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Lee CM, Zane NR, Veal G, Thakker DR. Physiologically Based Pharmacokinetic Models for Adults and Children Reveal a Role of Intracellular Tubulin Binding in Vincristine Disposition. CPT Pharmacometrics Syst Pharmacol 2019; 8:759-768. [PMID: 31420944 PMCID: PMC6813170 DOI: 10.1002/psp4.12453] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 06/11/2019] [Indexed: 11/30/2022] Open
Abstract
Vincristine is a cytotoxic chemotherapeutic agent used as first-line therapy for pediatric acute lymphocytic leukemia. It is cleared by hepatic oxidative metabolism by CYP3A4 and CYP3A5 and via hepatic (biliary) efflux mediated by P-glycoprotein (P-gp) transporter. Bottom-up physiologically based pharmacokinetic (PBPK) models were developed to predict vincristine disposition in pediatric and adult populations. The models incorporated physicochemical properties, metabolism by CYP3A4/5, efflux by P-gp, and intracellular binding to β-tubulin. The adult and pediatric PBPK models predicted pharmacokinetics (PK) within twofold of the observed PK parameters (area under the curve, terminal half-life, volume of distribution, and clearance). Simulating a higher hypothetical (4.9-fold) pediatric expression of β-tubulin relative to adult improved predictions of vincristine PKs. To our knowledge, this is the first time that intracellular binding has been incorporated into a pediatric PBPK model. Utilizing this PBPK modeling approach, safe and effective doses of vincristine could be predicted.
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Affiliation(s)
- Christine M. Lee
- Division of Pharmacotherapy and Experimental TherapeuticsUNC Eshelman School of PharmacyThe University of North Carolina at Chapel HillChapel HillNorth CarolinaUSA
| | - Nicole R. Zane
- The Center for Clinical Pharmacology at The Children's Hospital of PhiladelphiaPhiladelphiaPennsylvaniaUSA
| | - Gareth Veal
- Northern Institute for Cancer ResearchNewcastle UniversityNewcastle upon TyneUK
| | - Dhiren R. Thakker
- Division of Pharmacotherapy and Experimental TherapeuticsUNC Eshelman School of PharmacyThe University of North Carolina at Chapel HillChapel HillNorth CarolinaUSA
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He D, Wu H, Ding L, Li Y. Combination of BCL11A siRNA with vincristine increases the apoptosis of SUDHL6 cells. Eur J Med Res 2014; 19:34. [PMID: 24961604 PMCID: PMC4086990 DOI: 10.1186/2047-783x-19-34] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Accepted: 06/11/2014] [Indexed: 02/02/2023] Open
Abstract
Background B cell chronic lymphocytic leukemia/lymphoma 11 A (BCL11A) is associated with human B cell malignancy initiation. Our previous study has shown that downregulation of BCL11A mRNA by small interfering RNA (siRNA) is capable of inducing apoptosis in the SUDHL6 cell line. To further explore the effects of BCL11A siRNA on the enhanced cytotoxicity of a chemotherapeutic drug, we investigated the effects of BCL11A siRNA combined with vincristine (VCR) on SUDHL6 cell proliferation and apoptosis. Methods Chemically synthesized BCL11A siRNA was transfected into SUDHL6 cells using the HiPerFect Transfection Reagent in combination with VCR. Cell proliferation was measured by the CCK8 assay. The morphology of apoptotic cells was observed with Hoechst 33258 staining. The rate of cell apoptosis was determined by annexin V-fluorescein isothiocyanate/propidium iodide double staining using fluorescence-activated cell sorting (FACS) analysis. Results After BCL11A siRNA plus VCR treatment, cell proliferation was significantly decreased in comparison with VCR or BCL11A siRNA treatment alone and negative control siRNA plus VCR treatment (P <0.05). The apoptotic rate of BCL11A siRNA plus VCR treated cells was significantly increased compared with BCL11A siRNA and VCR treatment alone and negative control siRNA plus VCR treatment (P <0.05). Conclusions The combination of BCL11A siRNA and VCR increases apoptosis in SUDHL6 cells. Our study implies that BCL11A siRNA in combination with VCR may be a useful approach for improving effective treatment for B cell lymphoma.
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Affiliation(s)
- Dongmei He
- Institute of Hematology, Medical College, Jinan University, No, 601, West Huangpu Road, Guangzhou, Tianhe District 510632, PR China.
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Zhang T, Zheng Y, Peng Q, Cao X, Gong T, Zhang Z. A novel submicron emulsion system loaded with vincristine-oleic acid ion-pair complex with improved anticancer effect: in vitro and in vivo studies. Int J Nanomedicine 2013; 8:1185-96. [PMID: 23658485 PMCID: PMC3607420 DOI: 10.2147/ijn.s41775] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Background Vincristine (VCR), which is a widely used antineoplastic drug, was integrated with a submicron-emulsion drug-delivery system to enhance the anticancer effect. Methods After the formation of a VCR-oleic acid ion-pair complex (VCR-OA), the VCR-OA-loaded submicron emulsion (VCR-OA-SME), prepared by classical high-pressure homogenization, was characterized and its in vitro anticancer effects were evaluated. Results The submicron-emulsion formulation exhibited a homogeneous round shape. The mean particle size, zeta potential, and encapsulation efficiency were 157.6 ± 12.6 nm, −26.5 ± 5.0 mV and 78.64% ± 3.44%, respectively. An in vitro release study of the VCR-OA-SME revealed that 12.4% of the VCR was released within the first 2 hours (initial burst-release phase) and the rest of the drug was detected in the subsequent sustained-release phase. Compared with VCR solution, the pharmacokinetic study of VCR-OA-SME showed relatively longer mean residence time (mean residence time [0–∞] increased from 187.19 to 227.56 minutes), higher maximum concentration (from 252.13 ng/mL to 533.34 ng/mL), and greater area under the curve (area under the curve [0–∞] from 11,417.77 μg/L/minute to 17,164.34 μg/L/minute. Moreover, the VCR-OA-SME exhibited higher cytotoxicity (P < 0.05) on tumor cells by inducing cell arrest in the G2/M phase or even apoptosis (P < 0.05). Conclusion The VCR-OA-SME formulation in our study displayed great potential for an anticancer effect for VCR.
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Affiliation(s)
- Ting Zhang
- Key Laboratory of Drug Targeting and Drug Delivery Systems, Sichuan University, Chengdu, People's Republic of China
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Verissimo CS, Cheng S, Puigvert JC, Qin Y, Vroon A, van Deutekom J, Price LS, Danen EHJ, van de Water B, Fitzsimons CP, Vreugdenhil E. Combining doublecortin-like kinase silencing and vinca alkaloids results in a synergistic apoptotic effect in neuroblastoma cells. J Pharmacol Exp Ther 2012; 342:119-30. [PMID: 22490379 DOI: 10.1124/jpet.111.188813] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Microtubule-destabilizing agents, such as vinca alkaloids (VAs), are part of the treatment currently applied in patients with high-risk neuroblastoma (NB). However, the development of drug resistance and toxicity make NB difficult to treat with these drugs. In this study we explore the combination of VAs (vincristine or vinblastine) with knockdown of the microtubule-associated proteins encoded by the doublecortin-like kinase (DCLK) gene by using short interference RNA (siRNA). We examined the effect of VAs and DCLK knockdown on the microtubule network by immunohistochemistry. We performed dose-response studies on cell viability and proliferation. By combining VA with DCLK knockdown we observed a strong reduction in the EC(50) to induce cell death: up to 7.3-fold reduction of vincristine and 21.1-fold reduction of vinblastine. Using time-lapse imaging of phosphatidylserine translocation and a terminal deoxynucleotidyl transferase dUTP nick-end labeling-based assay, we found a significant increase of apoptosis by the combined treatment. Induction of caspase-3 activity, as detected via cleavage of N-acetyl-Asp-Glu-Val-Asp-7-amido-4-methylcoumarin, showed a 3.3- to 12.0-fold increase in the combined treatment. We detected significant increases in caspase-8 activity as well. Moreover, the multidrug dose effect calculated by using the median effect method showed a strong synergistic inhibition of proliferation and induction of apoptosis at most of the combined concentrations of siRNAs and VAs. Together, our data demonstrate that the silencing of DCLK sensitizes NB cells to VAs, resulting in a synergetic apoptotic effect.
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Affiliation(s)
- Carla S Verissimo
- Division of Medical Pharmacology, Leiden/Amsterdam Center for Drug Research, Leiden, The Netherlands
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Lobert S, Jefferson B, Morris K. Regulation of β-tubulin isotypes by micro-RNA 100 in MCF7 breast cancer cells. Cytoskeleton (Hoboken) 2011; 68:355-62. [PMID: 21634028 DOI: 10.1002/cm.20517] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 05/03/2011] [Accepted: 05/17/2011] [Indexed: 12/21/2022]
Abstract
Antimitotic drugs are key components of combination chemotherapy protocols for hematological and solid tumors. The taxanes (e.g., paclitaxel) bind to the β subunit of the tubulin heterodimer and reduce microtubule dynamics, leading to cell cycle arrest in G2/M. The effectiveness of combination chemotherapy is limited by tumor resistance to drugs initially or as a cumulative effect after several cycles of treatment. Because changes in the drug receptor may be linked to drug resistance, we investigated changes in β-tubulin isotypes in response to paclitaxel treatment in MCF7 breast cancer cells. We found that paclitaxel induced a 2-3 fold increase in mRNA for β-tubulin IIA and III genes, TUBB2A, and TUBB3. β-Tubulin class III protein increased; however, β-tubulin class II protein was not detected in these cells. Paclitaxel treatment following pretreatment with actinomycin D showed that the change in β-tubulin class III was due to increased transcription and linked to G2/M arrest. The increase in β-tubulin IIA mRNA was due to both enhanced stability and increased transcription, unassociated with G2/M arrest. We used micro-RNA superarrays to look for changes in families of micro-RNAs that might be linked to drug-induced changes in β-tubulin isotype mRNA and/or protein. We found a significant decrease in the tumor suppressor, miR-100, in MCF7 cells in response to paclitaxel treatment. Transfection of MCF7 cells with miR-100 significantly reduced β-tubulin I, IIA, IIB and V mRNA and prevented paclitaxel-induced increases in β-tubulin isotypes. This is the first report of a micro-RNA that regulates these specific β-tubulin isotype mRNAs.
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Affiliation(s)
- Sharon Lobert
- School of Nursing, University of Mississippi Medical Center, Jackson, Mississippi 39216, USA.
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Abstract
This chapter describes the use of analytical ultracentrifugation in a Beckman XLA to study the self-association properties of tubulin and the interaction of tubulin with antimitotic drugs. Procedures for sample preparation, operation of the ultracentrifuge, and collection of data conform to standard modern methods. Analysis of sedimentation velocity data initially includes generation of g(s) sedimentation coefficient distributions with DCDT(+2) and determination of weight average sedimentation coefficients S(w). S(w) versus concentration data are then fit to isodesmic or indefinite assembly models to extract K(iso) values, the association constant for each successive assembly step. Alternatively the raw data can also be analyzed by direct boundary analysis methods using the program Sedanal. Direct boundary analysis also extracts the K(iso) value by fitting to the shape of the sedimentation boundary as a function of total concentration. While the fitting of weight average data as a function of protein or drug concentration to indefinite assembly models has been shown to be equivalent to direct boundary fitting of multiple data sets with Sedanal, direct boundary fitting is preferred because it robustly identifies the presence of irreversible aggregation or mechanisms that are more complex.
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Abstract
We developed tubulin purification strategies that allowed sufficient material to be produced for compound-screening projects. Tubulins were polymerized in the presence of compounds using either turbidometric or fluorescence polymerization assays. IC50 and EC50 values were calculated and used to determine ratios between host and target tubulin (TT) (e.g., IC50-neuronal tubulin/IC50-TT). This ratio can be compared between compounds to identify the ones which are most selective for a particular TT. We found ratios for different compounds ranged from 0.16 to 4.0 between neuronal and cancer cell tubulin indicating that the sequence and posttranslational heterogeneity between these tubulins are sufficient to identify selective ligands for the TT. Likewise, compounds compared between neuronal and fungal tubulin had ratios ranging from 0.03 to 0.60, and compounds compared between neuronal to plant tubulin had ratios ranging from 0.03 to 52. Considering these data, we believe cancer cell tubulin-targeted drugs could be obtained with ratios in excess of 20, herbicides with ratios in excess of 200, and fungicides in excess of 200.
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Ng JS. Vinflunine: review of a new vinca alkaloid and its potential role in oncology. J Oncol Pharm Pract 2010; 17:209-24. [DOI: 10.1177/1078155210373525] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objective: To review the pharmacology, pharmacokinetics, in vitro and in vivo efficacy, and safety profile of vinflunine in the treatment of various solid tumors. Data sources: A literature search was conducted using keywords included vinflunine, vinca alkaloid, Javlor, and solid tumor in PubMed/MEDLINE (1950—January 2009) and International Pharmaceutical Abstracts (1950—January 2009). Study selection and data extraction: Published studies, posters, and meeting abstracts evaluating the in vitro and in vivo efficacy of vinflunine were reviewed. Data synthesis: Vinflunine is the newest member of the vinca alkaloid family. It has the weakest affinity to tubulins, but is shown to have unique receptor-independent antiangiogenesis, and antimetastasis properties. After administration, it is distributed extensively into tissues, metabolized via the CYP3A4 system, and eventually excreted in urine and feces. Phase II/III trials reported activities of vinflunine in advanced stage nonsmall-cell lung cancer, metastatic breast cancer, metastatic renal cell carcinoma, transitional cell carcinomas of the urothelium, small-cell lung cancer, and malignant pleural mesothelioma as monotherapy and in combination with other chemotherapy agents. More ongoing trials are evaluating its use in other solid tumors and in combination regimens. The most common adverse events in these trials were hematological (anemia and neutropenia), constipation, fatigue, abdominal pain, and myalgia. Conclusions: Vinflunine is a new vinca alkaloid for the treatment of advanced staged solid tumors. Available data showed promising activities in various malignancies. Further studies are needed to further define vinflunine’s role in oncology.
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Affiliation(s)
- John S Ng
- Department of Pharmacy, Wolfson Children's Hospital, Jacksonville, FL, USA; College of Pharmacy, University of Florida, Jacksonville, FL, USA,
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Perez EA. Microtubule inhibitors: Differentiating tubulin-inhibiting agents based on mechanisms of action, clinical activity, and resistance. Mol Cancer Ther 2009; 8:2086-95. [PMID: 19671735 DOI: 10.1158/1535-7163.mct-09-0366] [Citation(s) in RCA: 372] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Microtubules are important cellular targets for anticancer therapy because of their key role in mitosis. Microtubule inhibitors (MTI) such as taxanes, vinca alkaloids, and epothilones stabilize or destabilize microtubules, thereby suppressing microtubule dynamics required for proper mitotic function, effectively blocking cell cycle progression and resulting in apoptosis. In spite of their antitumor activity, innate or acquired drug resistance to MTIs such as the taxanes is common, limiting their overall clinical efficacy. Further insight into the mechanisms of action of microtubule-targeting drugs has lead to the discovery of novel agents that may provide higher efficacy with limited toxicity and help overcome resistance to conventional MTIs. This review will focus on the different mechanisms of action of MTIs, potential factors related to resistance and tolerability, and will discuss the recent approval as well as the development of new antineoplastic agents.
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Affiliation(s)
- Edith A Perez
- Division of Hematology and Oncology, Mayo Clinic, Jacksonville, FL32224, USA.
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Gan PP, Kavallaris M. Tubulin-Targeted Drug Action: Functional Significance of Class II and Class IVb β-Tubulin in Vinca Alkaloid Sensitivity. Cancer Res 2008; 68:9817-24. [DOI: 10.1158/0008-5472.can-08-1501] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Cucchiarelli V, Hiser L, Smith H, Frankfurter A, Spano A, Correia JJ, Lobert S. β‐tubulin isotype classes II and V expression patterns in nonsmall cell lung carcinomas. ACTA ACUST UNITED AC 2008; 65:675-85. [DOI: 10.1002/cm.20297] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Aggarwal A, Kruczynski A, Frankfurter A, Correia JJ, Lobert S. Murine leukemia P388 vinorelbine-resistant cell lines are sensitive to vinflunine. Invest New Drugs 2007; 26:319-30. [DOI: 10.1007/s10637-007-9102-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2007] [Accepted: 11/15/2007] [Indexed: 11/28/2022]
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Lu PH, Kung FL, Kuo SC, Chueh SC, Guh JH. Investigation of anti-tumor mechanisms of K2154: characterization of tubulin isotypes, mitotic arrest and apoptotic machinery. Naunyn Schmiedebergs Arch Pharmacol 2006; 374:223-33. [PMID: 17102938 DOI: 10.1007/s00210-006-0114-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2006] [Accepted: 10/19/2006] [Indexed: 10/23/2022]
Abstract
Microtubules are crucial targets for cancer chemotherapeutic drugs, and new microtubule-directed agents are of continued interest in drug development. A novel microtubule-directed agent, ethyl-2-[N-rho-chlorobenzyl-(2'-methoxy)]-anilino-4-oxo -4, 5-dihydro-furan-3-carboxylate, was identified. The compound, designated K2154, inhibited cell proliferation, with IC(50) values of 10.3, 15.3, 9.6, 11.2, 12.8 and 12.1 muM in prostate cancer PC-3, hepatocellular carcinoma Hep3B, non-small cell lung cancer A549, colorectal cancer HT29 and HCT116, and P-glycoprotein-rich breast cancer NCI/ADR-RES cells, respectively. Because NCI/ADR-RES cells were susceptible to inhibition by K2154, it indicated that this compound is a poor substrate for P-glycoprotein. In this study, PC-3 cells were used to identify the anticancer mechanisms of K2154. K2154 induced an arrest of the cell cycle at G2/M phase and a subsequent increase of hypodiploid phase in PC-3 cells, whereas it only induced a moderate level of G2/M arrest with little increase of hypodiploid phase in normal prostate cells. K2154 inhibited microtubule assembly in both in vitro turbidity assay and in vivo microtubule spin-down experiment. Immunochemical examination showed that K2154 caused formation of abnormal mitotic characteristics with bipolar spindles, particularly, in beta(II)- and beta(III)-tubulin staining. It also induced several pathways, including cyclin B1 up-regulation, dephosphorylation on Tyr(15) and phosphorylation on Thr(161) of Cdk1 and Cdc25C phosphorylation, and roscovitine (a Cdk1 inhibitor) significantly inhibited K2154-induced apoptosis, suggesting a pro-apoptotic role of Cdk1. Phosphorylation of Bcl-2 and Bcl-xL and cleavage of Mcl-1, together with activation of caspase-9 and -3, indicated that mitochondrial pathway played a central role in K2154-mediated apoptotic cell death. Additionally, AIF contributed to a late phase of K2154-induced apoptotic pathway. In conclusion, it is suggested that K2154 displays an anticancer activity through a target on microtubules and a subsequent signaling cascade on cell cycle regulation and apoptotic machinery.
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Affiliation(s)
- Pin-Hsuan Lu
- School of Pharmacy, College of Medicine, National Taiwan University, Taipei, Taiwan
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Torin Huzil J, Ludueña RF, Tuszynski J. Comparative modelling of human β tubulin isotypes and implications for drug binding. NANOTECHNOLOGY 2006; 17:S90-S100. [PMID: 21727360 DOI: 10.1088/0957-4484/17/4/014] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The protein tubulin is a target for several anti-mitotic drugs, which affect microtubule dynamics, ultimately leading to cell cycle arrest and apoptosis. Many of these drugs, including the taxanes and Vinca alkaloids, are currently used clinically in the treatment of several types of cancer. Another tubulin binding drug, colchicine, although too toxic to be used as a chemotherapeutic agent, is commonly used for the treatment of gout. The main disadvantage that all of these drugs share is that they bind tubulin indiscriminately, leading to the death of both cancerous and healthy cells. However, the broad cellular distribution of several tubulin isotypes provides a platform upon which to construct novel chemotherapeutic drugs that could differentiate between different cell types, reducing the undesirable side effects associated with current chemotherapeutic treatments. Here, we report an analysis of ten human β tubulin isotypes and discuss differences within each of the previously characterized paclitaxel, colchicine and vinblastine binding sites.
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Affiliation(s)
- J Torin Huzil
- Department of Oncology, University of Alberta, Edmonton, AB, T6G 2J1, Canada
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Hiser L, Aggarwal A, Young R, Frankfurter A, Spano A, Correia JJ, Lobert S. Comparison of β-tubulin mRNA and protein levels in 12 human cancer cell lines. ACTA ACUST UNITED AC 2006; 63:41-52. [PMID: 16362954 DOI: 10.1002/cm.20109] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Antimitotic drugs are chemotherapeutic agents that bind tubulin and microtubules. Resistance to these drugs is a major clinical problem. One hypothesis is that the cellular composition of tubulin isotypes may predict the sensitivity of a tumor to antimitotics. Reliable and sensitive methods for measuring tubulin isotype levels in cells and tissues are needed to address this hypothesis. Quantitative measurements of tubulin isotypes have frequently relied upon inferring protein amounts from mRNA levels. To determine whether this approach is justified, protein and mRNA levels of beta-tubulin isotypes from 12 human cancer cell lines were measured. This work focused on only beta-tubulin isotypes because we had readily available monoclonal antibodies for quantitative immunoblots. The percentage of beta-tubulin isotype classes I, II, III, and IVa + IVb mRNA and protein were compared. For beta-tubulin class I that comprises >50% of the beta-tubulin protein in 10 of the 12 cell lines, there was good agreement between mRNA and protein percentages. Agreement between mRNA and protein was also found for beta-tubulin class III. For beta-tubulin classes IVa + IVb, we observed higher protein levels compared to mRNA levels.Beta-tubulin class II protein was found in only four cell lines and in very low abundance. We conclude that quantitative Western blotting is a reliable method for measuring tubulin isotype levels in human cancer cell lines. Inferring protein amounts from mRNA levels should be done with caution, since the correspondence is not one-to-one for all tubulin isotypes.
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Affiliation(s)
- Laree Hiser
- School of Nursing, University of Mississippi Medical Center, Jackson, MS 39216, USA
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Downing KH. Structural basis for the action of drugs that affect microtubule dynamics. ACTA ACUST UNITED AC 2005. [DOI: 10.1517/14728222.4.2.219] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Dozier JH, Hiser L, Davis JA, Thomas NS, Tucci MA, Benghuzzi HA, Frankfurter A, Correia JJ, Lobert S. Beta class II tubulin predominates in normal and tumor breast tissues. Breast Cancer Res 2003; 5:R157-69. [PMID: 12927047 PMCID: PMC314434 DOI: 10.1186/bcr631] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2002] [Revised: 06/27/2003] [Accepted: 07/07/2003] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Antimitotic chemotherapeutic agents target tubulin, the major protein in mitotic spindles. Tubulin isotype composition is thought to be both diagnostic of tumor progression and a determinant of the cellular response to chemotherapy. This implies that there is a difference in isotype composition between normal and tumor tissues. METHODS To determine whether such a difference occurs in breast tissues, total tubulin was fractionated from lysates of paired normal and tumor breast tissues, and the amounts of beta-tubulin classes I + IV, II, and III were measured by competitive enzyme-linked immunosorbent assay (ELISA). Only primary tumor tissues, before chemotherapy, were examined. Her2/neu protein amplification occurs in about 30% of breast tumors and is considered a marker for poor prognosis. To gain insight into whether tubulin isotype levels might be correlated with prognosis, ELISAs were used to quantify Her2/neu protein levels in these tissues. RESULTS Beta-tubulin isotype distributions in normal and tumor breast tissues were similar. The most abundant beta-tubulin isotypes in these tissues were beta-tubulin classes II and I + IV. Her2/neu levels in tumor tissues were 5-30-fold those in normal tissues, although there was no correlation between the Her2/neu biomarker and tubulin isotype levels. CONCLUSION These results suggest that tubulin isotype levels, alone or in combination with Her2/neu protein levels, might not be diagnostic of tumorigenesis in breast cancer. However, the presence of a broad distribution of these tubulin isotypes (for example, 40-75% beta-tubulin class II) in breast tissue, in conjunction with other factors, might still be relevant to disease progression and cellular response to antimitotic drugs.
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Affiliation(s)
- James H Dozier
- School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Laree Hiser
- School of Nursing, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Jennifer A Davis
- School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Nancy Stubbs Thomas
- School of Nursing, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Michelle A Tucci
- School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Hamed A Benghuzzi
- School of Health Related Professions, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Anthony Frankfurter
- Department of Biology, University of Virginia, Charlottesville, Virginia, USA
| | - John J Correia
- School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Sharon Lobert
- School of Nursing, University of Mississippi Medical Center, Jackson, Mississippi, USA
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Khan IA, Ludueña RF. Different effects of vinblastine on the polymerization of isotypically purified tubulins from bovine brain. Invest New Drugs 2003; 21:3-13. [PMID: 12795525 DOI: 10.1023/a:1022946305242] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Vinblastine, a highly successful antitumor drug, targets the tubulin molecule. Tubulin, the subunit protein of microtubules, consists of an alpha- and a beta-subunit, both of which consist of isotypes encoded by different genes. We have purified three isotypes of bovine brain tubulin, namely, alpha(beta)II, alpha(beta)III and alpha(beta)IV. Microtubule associated protein-2 (MAP2) and Tau-induced assembly of these isotypes were compared in the presence and absence of vinblastine. MAP2-induced assembly of unfractionated tubulin and all the isotypes except alpha(beta)II tubulin was resistant to 1 microM vinblastine. Vinblastine at low concentrations (< 10 microM) progressively inhibited the assembly of all of the isotypes but the vinblastine concentration required for inhibition of MAP2-induced microtubule assembly was minimal for alpha(beta)II. The tau-induced assembly of unfractionated tubulin and alpha(beta)III were equally sensitive to 1 microM vinblastine whereas alpha(beta)II and alpha(beta)IV were much more sensitive to vinblastine. The microtubules obtained in the presence of tau from unfractionated tubulin, alpha(beta)II and alpha(beta)IV could be easily aggregated by 20 microM vinblastine whereas such as aggregation of microtubules obtained from alpha(beta)III and tau required approximatedly 40 microM vinblastine. Our results suggest that among the tubulin isotypes, alpha(beta)II is the most sensitive to vinblastine in the presence of MAPs while alpha(beta)III is the most resistant and this intrinsic resistance of alpha(beta)III dimers persists in the polymeric form of alpha(beta)III tubulin as well. These results may be relevant to the therapeutic and toxic actions of vinblastine.
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Affiliation(s)
- Israr A Khan
- Department of Biochemistry, University of Texas Science Center, San Antonio, TX 78229-3900, USA
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Arai K, Maruo K, Ara KY, Uehara K, Matsuda H. Characterization of isotype-specific regions of five classes of canine beta-tubulin and their expression in several tissues and cell culture. J Vet Med Sci 2001; 63:1297-302. [PMID: 11789607 DOI: 10.1292/jvms.63.1297] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The structure of isotype-specific regions of classes 1, II, III, IVa and IVb of canine beta-tubulin was characterized by 3'-RACE and the expression of these isotypes in canine tissues was examined by ribonuclease protection assay (RPA). Furthermore, a malignant mammary tumor-derived osteosarcoma-like cell line was established and the altered expression of beta-tubulin isotypes in taxol-resistant sublines was analyzed. The deduced amino acid sequences in isotype-specific regions corresponding to classes I, II and IVb were identical to those of humans and mice, but those in classes III and IVa showed slight differences among species. RPA revealed that classes I and IVb were widely distributed, but classes II, III and IVa were restricted to the brain. Because RPA could clearly distinguish the expression of class IVa from that of class IVb, it was thought to be more useful than northern blot for analysis of beta-tubulin isotype expression. In vitro, taxol-resistant sublines displayed a significant increase in class IVa as compared with taxol-sensitive cells, suggesting that altered expression of class IVa was associated with taxol resistance in these cell lines.
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Affiliation(s)
- K Arai
- Department of Tissue Physiology, Tokyo University of Agriculture and Technology, Fuchu, Japan
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Burkhart CA, Kavallaris M, Band Horwitz S. The role of beta-tubulin isotypes in resistance to antimitotic drugs. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1471:O1-9. [PMID: 11342188 DOI: 10.1016/s0304-419x(00)00022-6] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- C A Burkhart
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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Affiliation(s)
- S Lobert
- School of Nursing, University of Mississippi Medical Center, Jackson, Mississippi 39216, USA
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Affiliation(s)
- J J Correia
- Department of Biochemistry, University of Mississippi Medical Center, Jackson 39216-4505, USA
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