Vinblastine
Description
Historical Context of Discovery and Early Research
The discovery of vinblastine traces back to the serendipitous investigations into the traditional medicinal uses of the Madagascar periwinkle plant, Catharanthus roseus (formerly known as Vinca rosea) wikipedia.orgnih.govnih.govdrugbank.commdpi.comnih.govresearchgate.net. Folk remedies in Jamaica utilized a tea from this plant for its purported anti-diabetic effects wikipedia.orgnih.govnih.govresearchgate.net. In the 1950s, Canadian scientists Robert Noble and Charles Thomas Beer at the University of Western Ontario began researching extracts from the plant wikipedia.orgutppublishing.com.
Their pivotal observation emerged when rabbits, injected with plant extracts to study the plant's alleged anti-diabetic properties, unexpectedly died from bacterial infections due to a significant decrease in white blood cells wikipedia.orgnih.govnih.gov. This unforeseen outcome led to the crucial hypothesis that the active compound might be effective against cancers involving white blood cells, such as lymphoma wikipedia.orgnih.govnih.govresearchgate.net. This compound was subsequently isolated in 1958 wikipedia.orgutppublishing.com. The initial clinical trials for this compound followed in 1959 utppublishing.com. This discovery, alongside that of its closely related analogue vincristine, spurred extensive efforts by the United States National Cancer Institute (NCI) to identify other plant-derived anticancer agents mdpi.com.
Classification and Structural Characteristics within Vinca Alkaloids
This compound is classified as a vinca alkaloid, a group of naturally occurring or semi-synthetic nitrogenous bases derived from the Catharanthus roseus plant nih.govnih.govdrugbank.commdpi.com. These compounds are characterized by their intricate dimeric chemical structures, which are formed from the coupling of two distinct multiringed units: an indole nucleus, specifically catharanthine, and a dihydroindole nucleus, known as vindoline nih.govnih.govdrugbank.commdpi.com.
The chemical formula for this compound is C₄₆H₅₈N₄O₉ wikipedia.orgnih.gov. It is biosynthetically formed through the coupling of catharanthine (C₂₁H₂₄N₂O₂) and vindoline (C₂₅H₃₂N₂O₆) mdpi.comsciensage.infompg.de. A notable structural distinction exists between this compound and its well-known counterpart, vincristine. While both share an identical upper velbanamine subunit and nearly identical vindoline-derived lower subunits, they differ at a single substitution on the indole nitrogen of the vindoline skeleton: this compound possesses a methyl group, whereas vincristine features a formyl group nih.govmdpi.comacs.org. This seemingly minor structural variation leads to distinct biological profiles for each compound nih.gov.
General Significance in Chemical Biology and Natural Product Research
This compound holds significant importance in chemical biology and natural product research due to its complex molecular architecture and its profound interactions with cellular machinery. As a natural product, its intricate dimeric alkaloid structure has been a subject of considerable interest, inspiring rigorous studies into its biosynthesis and chemical synthesis pnas.org.
A key contribution of this compound to chemical biology lies in its role as one of the pioneering small molecules identified to bind to tubulin and inhibit microtubule formation and mitosis pnas.org. This interaction established tubulin as a critical target in oncology and provided a foundational understanding of a mechanism of action that remains central to drug discovery today pnas.org.
In natural product research, the study of this compound's biosynthesis in Catharanthus roseus has provided invaluable insights into complex metabolic pathways within plants. Research has revealed that the entire biosynthetic pathway for this compound is compartmentalized and organized across three distinct cell types within the plant: specialized cells associated with vascular bundles (IPAP), epidermal cells, and rare idioblast cells mpg.de. Understanding these cellular and biochemical intricacies is crucial for elucidating how complex natural products are formed in biological systems mpg.de.
Furthermore, advances in the total synthesis of this compound have facilitated the creation of novel, more potent analogues that are otherwise inaccessible through traditional natural product derivatization, late-stage functionalization, or biosynthetic methods pnas.orgacs.org. This highlights how synthetic chemistry can expand upon the chemical diversity found in nature, allowing for systematic structure-function studies and the exploration of new chemical space to optimize the properties of natural products for various biological applications pnas.orgacs.org. The study of this compound continues to inspire the development of powerful new synthetic methodologies, underscoring its enduring significance in both chemical biology and natural product research acs.org.
Properties
Key on ui mechanism of action |
The antitumor activity of vinblastine is thought to be due primarily to inhibition of mitosis at metaphase through its interaction with tubulin. Vinblastine binds to the microtubular proteins of the mitotic spindle, leading to crystallization of the microtubule and mitotic arrest or cell death. Although the mechanism of action has not been definitely established, vinblastine appears to bind to or crystallize critical microtubular proteins of the mitotic spindle, thus preventing their proper polymerization and causing metaphase arrest. In high concentrations, vinblastine also exerts complex effects on nucleic acid and protein synthesis. Vinblastine reportedly also interferes with amino acid metabolism by blocking cellular utilization of glutamic acid and thus inhibits purine synthesis, the citric acid cycle, and the formation of urea. Vinblastine exerts some immunosuppressive activity. Experimental data indicate that the action of vinblastine sulfate is different from that of other recognized antineoplastic agents. Tissue-culture studies suggest an interference with metabolic pathways of amino acids leading from glutamic acid to the citric acid cycle and to urea. In vivo experiments tend to confirm the in vitro results. A number of in vitro and in vivo studies have demonstrated that vinblastine sulfate produces a stathmokinetic effect and various atypical mitotic figures. ... Studies indicate that vinblastine sulfate has an effect on cell-energy production required for mitosis and interferes with nucleic acid synthesis. The mechanism of action of vinblastine sulfate has been related to the inhibition of microtubule formation in the mitotic spindle, resulting in an arrest of dividing cells at the metaphase stage. Reversal of the antitumor effect of vinblastine sulfate by glutamic acid or tryptophan has been observed. In addition, glutamic acid and aspartic acid have protected mice from lethal doses of vinblastine sulfate. Aspartic acid was relatively ineffective in reversing the antitumor effect. |
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CAS No. |
865-21-4 |
Molecular Formula |
C46H58N4O9 |
Molecular Weight |
811.0 g/mol |
IUPAC Name |
methyl (9R,10S,11R,12R,19R)-11-acetyloxy-12-ethyl-4-[(13S,15R,17S)-17-ethyl-17-hydroxy-13-methoxycarbonyl-1,11-diazatetracyclo[13.3.1.04,12.05,10]nonadeca-4(12),5,7,9-tetraen-13-yl]-10-hydroxy-5-methoxy-8-methyl-8,16-diazapentacyclo[10.6.1.01,9.02,7.016,19]nonadeca-2,4,6,13-tetraene-10-carboxylate |
InChI |
InChI=1S/C46H58N4O9/c1-8-42(54)23-28-24-45(40(52)57-6,36-30(15-19-49(25-28)26-42)29-13-10-11-14-33(29)47-36)32-21-31-34(22-35(32)56-5)48(4)38-44(31)17-20-50-18-12-16-43(9-2,37(44)50)39(59-27(3)51)46(38,55)41(53)58-7/h10-14,16,21-22,28,37-39,47,54-55H,8-9,15,17-20,23-26H2,1-7H3/t28-,37-,38+,39+,42-,43+,44?,45-,46-/m0/s1 |
InChI Key |
JXLYSJRDGCGARV-JQQWJEIDSA-N |
SMILES |
CCC1(CC2CC(C3=C(CCN(C2)C1)C4=CC=CC=C4N3)(C5=C(C=C6C(=C5)C78CCN9C7C(C=CC9)(C(C(C8N6C)(C(=O)OC)O)OC(=O)C)CC)OC)C(=O)OC)O |
Isomeric SMILES |
CC[C@@]1(C[C@H]2C[C@@](C3=C(CCN(C2)C1)C4=CC=CC=C4N3)(C5=C(C=C6C(=C5)C78CCN9[C@H]7[C@@](C=CC9)([C@H]([C@@]([C@@H]8N6C)(C(=O)OC)O)OC(=O)C)CC)OC)C(=O)OC)O |
Canonical SMILES |
CCC1(CC2CC(C3=C(CCN(C2)C1)C4=CC=CC=C4N3)(C5=C(C=C6C(=C5)C78CCN9C7C(C=CC9)(C(C(C8N6C)(C(=O)OC)O)OC(=O)C)CC)OC)C(=O)OC)O |
Color/Form |
Solvated needles from methanol |
melting_point |
211-216 °C |
Other CAS No. |
865-21-4 |
physical_description |
Solid |
shelf_life |
SOLN MAY BE STORED IN REFRIGERATOR FOR PERIODS OF 30 DAYS WITHOUT SIGNIFICANT LOSS OF POTENCY /VINBLASTINE SULFATE/ |
solubility |
Negligible ODORLESS & HYGROSCOPIC; WHITE TO SLIGHTLY YELLOW, AMORPHOUS OR CRYSTALLINE POWDER; FREELY SOL IN WATER /VINBLASTINE SULFATE/ Practically insoluble in water, petroleum ether; soluble in alcohols, acetone, ethyl acetate, chloroform |
Synonyms |
cellblastin Lemblastine Sulfate, Vinblastine Velban Velbe Vinblastin Hexal Vinblastina Lilly Vinblastine Vinblastine Sulfate Vinblastinsulfat-Gry Vincaleukoblastine |
vapor_pressure |
1.03X10-27 mm Hg at 25 °C (est) |
Origin of Product |
United States |
Vinblastine Biosynthesis and Production Methodologies
Natural Biosynthesis Pathway in Catharanthus roseus
The biosynthesis of vinblastine in Catharanthus roseus is a highly complex process, involving over 50 biosynthetic events and more than 30 enzymatic steps. oup.comhep.com.cnacs.orgfrontiersin.org This elaborate pathway begins with the condensation of two primary precursors: secologanin, derived from the terpenoid pathway, and tryptamine, originating from the indole pathway. These two molecules combine to form strictosidine, a pivotal intermediate that serves as the common precursor for all terpenoid indole alkaloids (TIAs) produced by the plant. hep.com.cnwikipedia.orgnih.govmdpi.com
This compound itself is a bisindole alkaloid, meaning it is formed from the dimerization of two distinct monomeric indole alkaloids: vindoline and catharanthine. oup.comhep.com.cnwikipedia.orgnih.govmdpi.comwikipedia.orgeurekalert.orgresearchgate.nettaylorandfrancis.comnih.gov Vindoline's biosynthesis proceeds from tabersonine through a well-established six-step enzymatic pathway. hep.com.cnmdpi.comsciensage.infowikipedia.org While catharanthine is also derived from strictosidine, the precise enzymatic steps and mechanisms involved in its formation are less comprehensively understood compared to vindoline. wikipedia.orgwikipedia.org
A critical step in this compound biosynthesis is the dimerization of vindoline and catharanthine, which yields α-3',4'-anhydrothis compound (AHVB). hep.com.cnwikipedia.orgnih.govmdpi.comresearchgate.net This condensation reaction is specifically catalyzed by a vacuolar class III peroxidase known as CrPrx1 (peroxidase 1). hep.com.cnwikipedia.orgmdpi.comresearchgate.net AHVB then acts as the common precursor for the subsequent formation of dimeric alkaloids, including this compound and vincristine. hep.com.cnwikipedia.orgnih.gov However, the exact enzymes responsible for the conversion of AHVB to this compound, and subsequently to vincristine, have not yet been fully characterized or isolated. hep.com.cnwikipedia.orgnih.gov
Key enzymes identified in the vindoline biosynthetic pathway, converting tabersonine to vindoline, include tabersonine 16-hydroxylase (T16H), desacetoxyvindoline 4-hydroxylase (D4H), and deacetylvindoline-4-O-acetyltransferase (DAT). hep.com.cnmdpi.comresearchgate.net The entire pathway, from the yeast native metabolites geranyl pyrophosphate and tryptophan to this compound, involves approximately 30 enzymatic steps and one chemical step. oup.comnih.gov
The biosynthesis of terpenoid indole alkaloids (TIAs) in Catharanthus roseus is spatially compartmentalized within different cell types of the plant, demonstrating an intricate division of labor. biorxiv.orgresearchgate.netacs.orgpnas.org The initial stages of the pathway, including the methylerythritol phosphate (MEP) and iridoid stages that lead to the production of secologanin, occur within specialized internal phloem-associated parenchyma (IPAP) cells. biorxiv.orgacs.orgpnas.org Subsequently, the alkaloid scaffolding steps, which involve the formation of strictosidine and its conversion into monomeric alkaloids like vindoline and catharanthine, take place in the epidermal cells. biorxiv.orgacs.orgpnas.org The final known steps of the pathway, encompassing the complete biosynthesis of vindoline and the crucial dimerization reaction that forms this compound precursors, are localized to rare and specialized cells known as idioblasts and laticifer cells, which are distributed throughout the plant's leaves. biorxiv.orgresearchgate.netacs.orgpnas.org Both vindoline and catharanthine are predominantly accumulated in the leaf tissue of C. roseus. wikipedia.org
Enzymatic Steps and Pathway Elucidation
Challenges of Traditional Natural Extraction
Traditional methods for extracting this compound from Catharanthus roseus present significant challenges due to the compound's inherently low concentration within the plant. oup.comwikipedia.orgnih.govtandfonline.comnih.govresearchgate.netijpsr.comsld.cu Producing a mere gram of this compound can necessitate over 2000 kg of dried leaves, or approximately 500 kg for 1 gram, highlighting the inefficiency and high resource demand of natural extraction. oup.comsld.cu The complex chemical structure of this compound also renders direct chemical synthesis difficult and cost-prohibitive. oup.comeurekalert.org Furthermore, the reliance on plant cultivation makes the supply chain vulnerable to various external factors, including plant diseases, natural disasters, and disruptions in global logistics. oup.com Conventional extraction techniques such as Soxhlet extraction, ultrasonication, and reflux often suffer from drawbacks like extended preparation times and low extraction efficiency. nih.gov
Biotechnological Approaches for Enhanced this compound Production
Given the limited natural supply and high global demand for this compound, there is an urgent need for alternative, more cost-effective, and sustainable production methods. oup.comijpsr.comsld.cuopenaccesspub.org Biotechnological strategies have emerged as promising avenues to enhance this compound production. These approaches include various in vitro culture techniques such as hairy root culture, callus cultures, shoot cultures, and cell suspension cultures. ijpsr.comsld.cuopenaccesspub.orggoogle.comnih.gov Additionally, metabolic engineering and the strategic use of elicitors (molecules that stimulate secondary metabolite production) are being explored to boost alkaloid accumulation. ijpsr.comsld.cuopenaccesspub.orggoogle.comnih.gov
A significant breakthrough in this compound production has been achieved through synthetic biology and genetic engineering, enabling the de novo biosynthesis of its precursors in microbial cell factories. oup.comeurekalert.orgnih.govuq.edu.auannualreviews.org Saccharomyces cerevisiae, commonly known as baker's yeast, has proven to be a highly adaptable chassis organism for this purpose. oup.comeurekalert.orgnih.govuq.edu.auannualreviews.org
Researchers have successfully reprogrammed engineered yeast strains to synthesize both vindoline and catharanthine. oup.comeurekalert.orgnih.gov This achievement involved the complex reconstitution of a 31-step biosynthetic pathway in yeast, requiring the expression of 34 heterologous genes from plants and the optimization of 10 native yeast genes to improve the supply of key precursors. oup.comnih.gov One study reported notable production titers of these precursors in engineered yeast strains via shake flask fermentation:
| Compound | Titer (μg/L) |
| Catharanthine | 527.1 |
| Vindoline | 305.1 |
Data based on shake flask fermentation in engineered Saccharomyces cerevisiae strains. eurekalert.org
While the biosynthesis of the monomeric precursors in yeast has been successful, the final step—the enzymatic condensation of vindoline and catharanthine to form this compound—has presented challenges for direct expression in yeast. Consequently, this critical dimerization step currently requires an in vitro chemical coupling. oup.com This in vitro chemical coupling of purified vindoline and catharanthine from engineered yeast has successfully yielded this compound at a concentration of 23.9 μg/L. oup.com This biotechnological approach offers a promising pathway for a stable and independent supply chain for this compound, reducing reliance on plant cultivation. oup.com
Mechanisms of Vinblastine Resistance in Preclinical Models
Overview of Multidrug Resistance (MDR) in Vinblastine Context
Multidrug resistance (MDR) refers to the ability of cancer cells to develop cross-resistance to multiple structurally and mechanistically unrelated chemotherapeutic agents, including this compound. plos.orgjci.orgresearchgate.net This phenomenon is a major impediment to successful cancer chemotherapy. researchgate.net In the context of this compound, MDR can arise from various cellular adaptations, leading to reduced intracellular drug accumulation, altered drug targets, or evasion of programmed cell death. Preclinical models, including various in vitro cell lines and in vivo animal models, have been instrumental in dissecting the complex mechanisms underlying this compound resistance. nih.govmdpi.comaacrjournals.org These models allow for the controlled study of acquired resistance, often through stepwise selection with increasing drug concentrations, or by characterizing innate resistance profiles. aacrjournals.org
Efflux Pump Overexpression and Function
One of the most prominent mechanisms of this compound resistance in preclinical models is the overexpression and enhanced function of ATP-binding cassette (ABC) efflux pumps. These transmembrane proteins actively transport drugs out of the cell, thereby reducing their intracellular concentration below therapeutic levels. researchgate.netscirp.orgspandidos-publications.comthno.org
Role of P-glycoprotein (P-gp/MDR1) in Drug Export
P-glycoprotein (P-gp), encoded by the ABCB1 (also known as MDR1) gene, is a well-characterized ABC efflux pump frequently implicated in this compound resistance. nih.govresearchgate.netscirp.orgspandidos-publications.commdpi.com P-gp utilizes energy from ATP hydrolysis to actively pump a broad range of structurally diverse cytotoxic agents, including this compound, out of cancer cells. nih.govresearchgate.netscirp.org Overexpression of functional P-gp leads to a significant reduction in the intracellular accumulation of this compound, directly contributing to drug resistance. nih.govresearchgate.netscirp.orgspandidos-publications.comthno.orgaacrjournals.org
Numerous preclinical studies have demonstrated the critical role of P-gp in this compound resistance:
In a panel of 359 cancer cell lines, high P-gp expression was strongly associated with a lack of response to this compound. aacrjournals.org
Mouse melanoma cell lines, such as B16F10, exhibit active efflux of vinca alkaloids mediated by P-glycoprotein. nih.gov
K562 human chronic myelogenous leukemia blast cells transfected with human MDR1 cDNA showed 20-30-fold resistance to this compound, which was associated with decreased cellular accumulation of the drug. jci.org This resistance was reversed by P-gp inhibitors like cyclosporin A. jci.org
In murine myeloma cells (P3X63Ag8.653), treatment with low doses of this compound led to the selection of resistant cells, and metabolomic analyses suggested that P-gp expression for MDR resistance is a function of metabolic adaptations in these cells. mdpi.com
Studies using Madin-Darby canine kidney (MDCK)-II and LLC-PK1 cells transfected with human MDR1 confirmed this compound as a P-gp substrate, with asymmetrical transport being much higher in MDR1-transfected cells compared to wildtype cells. nih.gov
In humanized mouse models, P-gp at the blood-brain barrier (BBB) plays a significant role in limiting this compound brain delivery, as Mdr1a(-/-) mice showed increased sensitivity to this compound compared to wild-type controls. plos.org
The human sarcoma cell line MES-SA, when subjected to single-step selection with this compound, predominantly developed MDR1 activation as the resistance mechanism, characterized by a typical drug efflux leading to reduced intracellular drug accumulation.
The sister of P-glycoprotein (SPGP) has also been shown to accelerate this compound efflux in LLC-PK1 cells, indicating its role in drug transport. researchgate.net
Other efflux transporters, such as Multidrug Resistance-associated Protein 1 (MRP1, encoded by ABCC1) and Breast Cancer Resistance Protein (BCRP), can also contribute to this compound efflux and resistance, often in conjunction with P-gp. plos.orgphysiology.orgfrontiersin.org For instance, both P-gp and MRP1 have been shown to contribute to this compound efflux in trophoblast cells. physiology.org
Table 1: Examples of P-gp Mediated this compound Resistance in Preclinical Models
| Preclinical Model (Cell Line/Organism) | Resistance Mechanism | Key Finding/Observation | Citation |
| Cancer Cell Lines (Panel of 359) | P-gp Overexpression | Strong association between high P-gp expression and lack of response to this compound (P = 0.004). aacrjournals.org | aacrjournals.org |
| K562 Human Leukemia Cells | MDR1 cDNA Transfection | 20-30-fold resistance to this compound; decreased cellular accumulation. jci.org | jci.org |
| Murine Myeloma Cells (P3X63Ag8.653) | P-gp Overexpression | Selection of this compound-resistant cells linked to P-gp expression and metabolic adaptations. mdpi.com | mdpi.com |
| MDCK-II and LLC-PK1 Cells (human MDR1 transfected) | P-gp Efflux Function | This compound identified as a P-gp substrate with high asymmetrical transport in transfected cells. nih.gov | nih.gov |
| Mdr1a(-/-) Mice | Lack of Mdr1a Gene | 3-fold more sensitive to this compound, highlighting P-gp's role at BBB. plos.org | plos.org |
| MES-SA Human Sarcoma Cells | MDR1 Activation | Predominant resistance mechanism in single-step selected cells, characterized by reduced intracellular drug accumulation. |
Strategies to Disrupt P-gp Binding and Transport
To circumvent P-gp mediated resistance, various strategies have been explored in preclinical models. These approaches primarily focus on inhibiting P-gp function, bypassing its efflux mechanism, or downregulating its expression.
P-gp Inhibitors: These agents directly block P-gp activity, allowing for increased intracellular accumulation of this compound. scirp.orgnih.gov P-gp inhibitors are broadly categorized into generations:
First-generation inhibitors like verapamil and cyclosporin A have shown the ability to reverse this compound resistance in vitro and in vivo. nih.govjci.orgaacrjournals.org For example, cyclosporin A reversed this compound resistance in K562 cells. jci.org Pervilleine A, a novel tropane alkaloid structurally resembling verapamil, effectively restored this compound sensitivity in multidrug-resistant KB-V1 and CEM/VLB100 cells in culture, with IC50 values of 0.36 μM and 0.02 μM respectively. aacrjournals.org
Second- and third-generation inhibitors , such as tariquidar and elacridar, were developed with improved specificity and reduced toxicity. scirp.orgnih.govaboutscience.eu Tariquidar, for instance, is more potent in blocking P-gp compared to BCRP. nih.gov
Nanotechnology: Nanoparticle-based drug delivery systems can encapsulate chemotherapeutic agents, allowing them to bypass P-gp-mediated efflux and deliver the drug directly into cancer cells, thereby increasing intracellular drug retention. scirp.orgthno.orgnih.gov
Alterations in Microtubule System Components
This compound's primary mechanism of action involves binding to tubulin dimers and inhibiting their polymerization into microtubules, leading to microtubule depolymerization and disruption of mitotic spindle formation. nih.govoncotarget.comsickkids.ca Therefore, alterations in the tubulin protein itself or in proteins that interact with the microtubule system can lead to this compound resistance. plos.orgoncotarget.comaacrjournals.orgaacrjournals.org
Tubulin Mutations and Isoform Expression Changes
Mutations in α- and β-tubulin, the building blocks of microtubules, can directly interfere with this compound binding or alter microtubule dynamics, leading to resistance. plos.orgaacrjournals.orgaacrjournals.org
Tubulin Mutations: Preclinical studies have identified specific mutations in tubulin that confer resistance to this compound. For example, Chinese hamster ovary (CHO) cells selected for resistance to Colcemid and this compound exhibited molecular changes in both α- and β-tubulin, leading to increased microtubule assembly and stability. aacrjournals.org In a KB-derived cancer cell line (KB-L30) resistant to microtubule destabilizers, six novel mutation sites were found in the exon four of the βI-tubulin gene, which were associated with altered microtubule assembly and dynamic instability. plos.org These mutations can result in hyperstable microtubules, making them less susceptible to this compound's depolymerizing effects. aacrjournals.org
Tubulin Isoform Expression Changes: Human cells express multiple isotypes of α- and β-tubulin, which can exhibit tissue-specific expression and differential roles in microtubule dynamics. aacrjournals.orgmdpi.com Altered expression of specific β-tubulin isotypes has been linked to this compound resistance:
Decreased expression of class III β-tubulin was observed in this compound-resistant CCRF-CEM-derived leukemia cell lines (VLB100). aacrjournals.org While some studies suggest a correlation between high class III β-tubulin expression and this compound sensitivity in renal cancer cell lines, others indicate its involvement in resistance to vinca alkaloids in various tumor types. mdpi.comaacrjournals.org
Increased expression of class I and IV β-tubulin has been reported in vinca alkaloid-resistant Chinese hamster ovary cells, associated with decreased binding of vincristine (a vinca alkaloid similar to this compound) to tubulin. aacrjournals.org
In K562 leukemia cells resistant to this compound (KCVB2), there was a reduction in total tubulin content, an increased polymerized fraction of total tubulin, and overexpression of class III β-tubulin, which is normally expressed at very low levels in parental K562 cells. sickkids.ca
Table 2: Tubulin Alterations and this compound Resistance in Preclinical Models
| Preclinical Model (Cell Line) | Tubulin Alteration | Effect on Microtubules/Resistance | Citation |
| CHO Cells | α- and β-Tubulin Mutations | Increased microtubule assembly and stability, conferring resistance to this compound. aacrjournals.org | aacrjournals.org |
| KB-L30 Cells | βI-Tubulin Mutations (V316D, T372S, S382L, E405K, E432K, G437K) | Altered microtubule assembly and dynamic instability, leading to resistance to microtubule destabilizers. plos.org | plos.org |
| CCRF-CEM-derived VLB100 Cells | Decreased Class III β-Tubulin Expression | Associated with this compound resistance. aacrjournals.org | aacrjournals.org |
| K562 Leukemia Cells (KCVB2) | Overexpression of Class III β-Tubulin, increased polymerized tubulin fraction | 8-fold resistance to this compound, cross-resistance to other vinca alkaloids. sickkids.ca | sickkids.ca |
| Renal Cell Carcinoma Cell Lines | Correlation between Class III β-Tubulin Expression and this compound Sensitivity | Significant correlation observed (r = 0.89, P = 0.033). aacrjournals.org | aacrjournals.org |
Modifications in Cytoskeletal Protein Interactions
Beyond tubulin itself, other proteins that interact with the microtubule and actin cytoskeletal systems can also influence this compound sensitivity and resistance.
Microtubule-Associated Proteins (MAPs): MAPs bind to and regulate microtubule dynamics and stability. oncotarget.comaacrjournals.org Increased expression of MAP4, which stabilizes microtubules, has been associated with decreased sensitivity to microtubule-depolymerizing agents like vinca alkaloids in leukemia cells. aacrjournals.org In vincristine-resistant and this compound-resistant leukemia cells, increased levels of MAP4 protein were observed. aacrjournals.org
Other Cytoskeletal Proteins: Proteomic studies have identified alterations in various cytoskeletal and cytoskeleton-associated proteins in drug-resistant cancer cell lines. oup.comnih.gov
γ-Actin: Alterations in γ-actin expression have been functionally linked to antimicrotubule drug resistance. oup.com Human neuroblastoma SH-EP cells with γ-actin siRNA displayed higher relative resistance to this compound. oup.com
Stathmin-1 (STMN1): Overexpression of stathmin-1, a microtubule-interacting protein that promotes microtubule depolymerization, can be associated with resistance to microtubule-targeting drugs. oncotarget.com
Other proteins like vimentin, 14-3-3σ, CLIC1, and ezrin have also shown differential expression in cells resistant to microtubule-stabilizing agents, suggesting their potential roles in modulating cytoskeletal dynamics and drug response. nih.govmdpi.com While these are primarily studied in the context of microtubule-stabilizing agents, their general involvement in cytoskeletal regulation suggests potential broader implications for resistance to microtubule-destabilizing agents like this compound.
Table 3: Modifications in Cytoskeletal Protein Interactions and this compound Resistance
| Preclinical Model (Cell Line) | Cytoskeletal Protein Alteration | Effect on this compound Resistance | Citation |
| CCRF-CEM-derived Leukemia Cells | Increased MAP4 Protein Levels | Associated with vincristine and this compound resistance. aacrjournals.org | aacrjournals.org |
| Human Neuroblastoma SH-EP Cells | γ-Actin siRNA (reduced γ-actin) | Higher relative resistance to this compound. oup.com | oup.com |
| Various Cancer Cell Lines | Overexpression of Stathmin-1 (STMN1) | Associated with resistance to microtubule-targeting drugs. oncotarget.com | oncotarget.com |
In Vivo Preclinical Models
In vivo models are critical for evaluating the systemic effects, efficacy, and pharmacological properties of a drug in a whole living organism before it can proceed to human clinical trials. mdpi.com Numerous in vivo studies have been conducted to investigate the antitumor activity of this compound. nih.gov
A common in vivo model is the tumor xenograft, where human tumor cells are implanted into immunodeficient mice, typically subcutaneously or at an orthotopic site (the organ of origin). aacrjournals.orgmdpi.com For example, orthotopic neuroblastoma models, where human neuroblastoma cells are injected into the adrenal gland of nude mice, have been used to show that this compound significantly inhibits tumor growth. aacrjournals.org These models also allow for the study of effects on angiogenesis and metastasis. aacrjournals.orgresearchgate.net
Other animal models have been employed to specifically study this compound's anti-angiogenic properties. The chick embryo chorioallantoic membrane (CAM) assay is a well-established model where the drug's effect on blood vessel formation can be directly observed. tandfonline.comaacrjournals.org In another model, angiogenesis is induced in the rat mesentery tissue by a growth factor, and the inhibitory effect of systemically administered this compound is quantified. tandfonline.com These studies have confirmed that this compound possesses dose-dependent anti-angiogenic activity in vivo. tandfonline.com Genetically engineered mouse models (GEMMs), where specific genes are altered to induce spontaneous tumor formation, provide a more accurate representation of human cancer genetics and the tumor microenvironment. mdpi.com While complex, these models are invaluable for validating drug targets and evaluating therapeutic efficacy. mdpi.com
Q & A
Q. How do researchers optimize in vitro models to study vinblastine’s effects on cancer cell proliferation?
Methodological Answer: In vitro models require standardization of cell lines (e.g., MCF-7, HepG2) and culture conditions. For cytotoxicity assays, use the MTT cell proliferation assay with this compound concentrations ranging from 0.00625 µM to 320 µM, depending on cell type and treatment duration . Ensure synchronization of cell cycles (e.g., lag, exponential, stationary phases) to account for phase-dependent drug accumulation, as this compound uptake varies significantly (e.g., 1.74 µg/mg in lag phase vs. 2.61 µg/mg in stationary phase) .
Q. What statistical methods are recommended for analyzing contradictory data in this compound pharmacokinetics?
Methodological Answer: Use ANOVA with post-hoc tests (e.g., Tukey’s HSD) to compare means across experimental groups. For dose-response studies, apply nonlinear regression models (e.g., log-logistic curves) to calculate IC50 values. Address outliers by combining parametric tests with nonparametric alternatives (e.g., Mann-Whitney U test) . When discrepancies arise in cytotoxicity data, systematically review variables like cell density, S9 metabolic activation, or solvent controls (e.g., DMSO interference) .
Advanced Research Questions
Q. How can researchers resolve contradictions in this compound’s mechanism of resistance across different cancer types?
Methodological Answer: Design comparative studies using RNA sequencing or CRISPR-Cas9 screens to identify resistance-associated genes (e.g., ABC transporters). Validate findings with functional assays, such as efflux inhibition via verapamil co-treatment. For clinical relevance, correlate in vitro resistance data with patient-derived xenograft (PDX) models and clinical trial datasets . Cross-validate results using orthogonal methods like flow cytometry for P-glycoprotein expression analysis .
Q. What experimental designs are effective for studying synergistic interactions between this compound and novel agents (e.g., nanoliposomal ceramides)?
Methodological Answer: Use the Chou-Talalay method to calculate combination indices (CI) via CalcuSyn software. Test fixed-ratio combinations (e.g., 1:1, 1:2) across multiple concentrations (e.g., 0.008–1 µM this compound + 12–24 µM ceramide). Measure synergy through caspase 3/7 activity assays and validate with Annexin V/PI staining . Ensure statistical rigor by performing ANOVA with Dunnett’s T-test to compare monotherapy vs. combination effects .
Q. How should researchers address variability in this compound accumulation data across cell cycle phases?
Methodological Answer: Synchronize cells using serum starvation or chemical inhibitors (e.g., thymidine block) before treatment. Quantify intracellular this compound via HPLC-MS/MS, normalizing to cell dry weight. Report phase-specific accumulation with error bars representing SEM (e.g., lag phase: 1.74 ± 0.2 µg/mg; stationary phase: 2.61 ± 0.3 µg/mg) . Use time-lapse microscopy to correlate accumulation dynamics with mitotic arrest.
Methodological Frameworks
Q. What protocols ensure reproducibility in this compound’s cytotoxicity assays?
- Cell Line Validation : Authenticate cell lines via STR profiling.
- Dose Standardization : Include positive controls (e.g., cyclophosphamide) and solvent controls .
- Data Reporting : Adhere to MIAME guidelines for omics data or ARRIVE guidelines for preclinical studies .
Q. How to design experiments investigating this compound’s impact on microtubule dynamics?
- Use fluorescently labeled tubulin (e.g., GFP-α-tubulin) and live-cell imaging to track polymerization rates.
- Compare this compound with other vinca alkaloids (e.g., vincristine) using EC50 values derived from dose-response curves .
Data Contradiction Analysis
Q. Why do studies report conflicting EC50 values for this compound in similar cell lines?
Potential Variables:
- Metabolic Activation : Inclusion/exclusion of S9 liver fractions alters drug metabolism .
- Assay Duration : Shorter exposures (24h) may underestimate cytotoxicity vs. prolonged treatments (72h).
- Normalization Methods : Data normalized to cell count vs. protein content yield divergent results .
Tables for Reference
Table 1 : this compound Accumulation in Catharanthus roseus Cell Cultures Across Growth Phases
| Growth Phase | Days Post-Culture | This compound (µg/mg dry weight) | Vincristine (µg/mg dry weight) |
|---|---|---|---|
| Lag | 3 | 1.74 ± 0.2 | 1.83 ± 0.3 |
| Exponential | 7 | 2.11 ± 0.3 | 2.27 ± 0.4 |
| Stationary | 12 | 2.61 ± 0.3 | 2.52 ± 0.2 |
Table 2 : Synergy Testing of this compound + C6-Ceramide in HepG2 Cells
| This compound (µM) | C6-Ceramide (µM) | Caspase 3/7 Activity (% Control) | p-value vs. Monotherapy |
|---|---|---|---|
| 0.008 | 12 | 145 ± 12 | <0.05 |
| 0.025 | 24 | 218 ± 18 | <0.01 |
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Please be aware that all articles and product information presented on BenchChem are intended solely for informational purposes. The products available for purchase on BenchChem are specifically designed for in-vitro studies, which are conducted outside of living organisms. In-vitro studies, derived from the Latin term "in glass," involve experiments performed in controlled laboratory settings using cells or tissues. It is important to note that these products are not categorized as medicines or drugs, and they have not received approval from the FDA for the prevention, treatment, or cure of any medical condition, ailment, or disease. We must emphasize that any form of bodily introduction of these products into humans or animals is strictly prohibited by law. It is essential to adhere to these guidelines to ensure compliance with legal and ethical standards in research and experimentation.
