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Battista T, Fiorillo A, Chiarini V, Genovese I, Ilari A, Colotti G. Roles of Sorcin in Drug Resistance in Cancer: One Protein, Many Mechanisms, for a Novel Potential Anticancer Drug Target. Cancers (Basel) 2020; 12:cancers12040887. [PMID: 32268494 PMCID: PMC7226229 DOI: 10.3390/cancers12040887] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 03/31/2020] [Accepted: 04/03/2020] [Indexed: 02/07/2023] Open
Abstract
The development of drug resistance is one of the main causes of failure in anti-cancer treatments. Tumor cells adopt many strategies to counteract the action of chemotherapeutic agents, e.g., enhanced DNA damage repair, inactivation of apoptotic pathways, alteration of drug targets, drug inactivation, and overexpression of ABC (Adenosine triphosphate-binding cassette, or ATP-binding cassette) transporters. These are broad substrate-specificity ATP-dependent efflux pumps able to export toxins or drugs out of cells; for instance, ABCB1 (MDR1, or P-glycoprotein 1), overexpressed in most cancer cells, confers them multidrug resistance (MDR). The gene coding for sorcin (SOluble Resistance-related Calcium-binding proteIN) is highly conserved among mammals and is located in the same chromosomal locus and amplicon as the ABC transporters ABCB1 and ABCB4, both in human and rodent genomes (two variants of ABCB1, i.e., ABCB1a and ABCB1b, are in rodent amplicon). Sorcin was initially characterized as a soluble protein overexpressed in multidrug (MD) resistant cells and named "resistance-related" because of its co-amplification with ABCB1. Although for years sorcin overexpression was thought to be only a by-product of the co-amplification with ABC transporter genes, many papers have recently demonstrated that sorcin plays an important part in MDR, indicating a possible role of sorcin as an oncoprotein. The present review illustrates sorcin roles in the generation of MDR via many mechanisms and points to sorcin as a novel potential target of different anticancer molecules.
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Affiliation(s)
- Theo Battista
- Department of Biochemical Sciences, Sapienza University, P.le A.Moro 5, 00185 Rome, Italy; (T.B.); (A.F.)
| | - Annarita Fiorillo
- Department of Biochemical Sciences, Sapienza University, P.le A.Moro 5, 00185 Rome, Italy; (T.B.); (A.F.)
| | - Valerio Chiarini
- Doctoral Programme in Integrative Life Science, Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland;
| | - Ilaria Genovese
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy;
| | - Andrea Ilari
- Institute of Molecular Biology and Pathology, Italian National Research Council, Istituto di Biologia e Patologia Molecolari, Consiglio Nazionale delle Ricerche (IBPM-CNR), c/o Department of Biochemical Sciences, Sapienza University, P.le A.Moro 5, 00185 Rome, Italy
- Correspondence: (A.I.); (G.C.)
| | - Gianni Colotti
- Institute of Molecular Biology and Pathology, Italian National Research Council, Istituto di Biologia e Patologia Molecolari, Consiglio Nazionale delle Ricerche (IBPM-CNR), c/o Department of Biochemical Sciences, Sapienza University, P.le A.Moro 5, 00185 Rome, Italy
- Correspondence: (A.I.); (G.C.)
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Genovese I, Ilari A, Assaraf YG, Fazi F, Colotti G. Not only P-glycoprotein: Amplification of the ABCB1- containing chromosome region 7q21 confers multidrug resistance upon cancer cells by coordinated overexpression of an assortment of resistance-related proteins. Drug Resist Updat 2017; 32:23-46. [DOI: 10.1016/j.drup.2017.10.003] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 10/01/2017] [Accepted: 10/11/2017] [Indexed: 02/07/2023]
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El-Araby ME, Omar AM, Khayat MT, Assiri HA, Al-Abd AM. Molecular Mimics of Classic P-Glycoprotein Inhibitors as Multidrug Resistance Suppressors and Their Synergistic Effect on Paclitaxel. PLoS One 2017; 12:e0168938. [PMID: 28068430 PMCID: PMC5222621 DOI: 10.1371/journal.pone.0168938] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2016] [Accepted: 12/08/2016] [Indexed: 01/05/2023] Open
Abstract
P-glycoprotein (Pgp) is a membrane bound efflux pump spread in a variety of tumor cells and considered as a main component of multidrug resistance (MDR) to chemotherapies. In this work, three groups of compounds (imidazolone, oxazolone and vinyl dipeptide derivatives) were synthesized aiming to develop a molecular framework that effectively suppresses MDR. When tested for their influence on Pgp activity, four compounds coded Cur1-01, Cur1-12V, Curox-1 and Curox-3 significantly decreased remaining ATP concentration indicating Pgp substrate site blocking. On the other hand, Cur-3 and Cur-10 significantly increased remaining ATP concentration, which is indicative of Pgp ATPase inhibition. The cytotoxicity of synthesized compounds was examined against Pgp expressing/highly resistant colorectal cancer cell lines (LS-174T). Compounds Cur-1 and Cur-3 showed considerable cytotoxicity with IC50 values of 7.6 and 8.9 μM, respectively. Equitoxic combination (at IC50 concentrations) of PTX and Cur-3 greatly diminished resistant cell clone from 45.7% to 2.5%, albeit with some drop in potency from IC50 of 7.9 nM to IC50 of 23.8 nM. On the other hand, combination of PTX and the non-cytotoxic Cur1-12V (10 μM) significantly decreased the IC50 of PTX to 3.8 nM as well as the resistant fraction to 16.2%. The combination test was confirmed using the same protocol but on another resistant CRC cell line (HCT-116) as we obtained similar results. Both Cur-3 and Cur1-12V (10 μM) significantly increased the cellular entrapment of Pgp probe (doxorubicin) elevating its intracellular concentration from 1.9 pmole/cell to 3.0 and 2.9 pmole/cell, respectively.
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Affiliation(s)
- Moustafa E. El-Araby
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia
- Department of Pharmaceutical Organic Chemistry, Faculty of Pharmacy, Helwan University, Cairo, Egypt
| | - Abdelsattar M. Omar
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt
| | - Maan T. Khayat
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Hanan A. Assiri
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Ahmed M. Al-Abd
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia
- Department of Pharmacology, Medical Division, National Research Centre, Cairo, Egypt
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Bloomfield M, Duesberg P. Inherent variability of cancer-specific aneuploidy generates metastases. Mol Cytogenet 2016; 9:90. [PMID: 28018487 PMCID: PMC5160004 DOI: 10.1186/s13039-016-0297-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 11/14/2016] [Indexed: 12/14/2022] Open
Abstract
Background The genetic basis of metastasis is still unclear because metastases carry individual karyotypes and phenotypes, rather than consistent mutations, and are rare compared to conventional mutation. There is however correlative evidence that metastasis depends on cancer-specific aneuploidy, and that metastases are karyotypically related to parental cancers. Accordingly we propose that metastasis is a speciation event. This theory holds that cancer-specific aneuploidy varies the clonal karyotypes of cancers automatically by unbalancing thousands of genes, and that rare variants form new autonomous subspecies with metastatic or other non-parental phenotypes like drug-resistance – similar to conventional subspeciation. Results To test this theory, we analyzed the karyotypic and morphological relationships between seven cancers and corresponding metastases. We found (1) that the cellular phenotypes of metastases were closely related to those of parental cancers, (2) that metastases shared 29 to 96% of their clonal karyotypic elements or aneusomies with the clonal karyotypes of parental cancers and (3) that, unexpectedly, the karyotypic complexity of metastases was very similar to that of the parental cancer. This suggests that metastases derive cancer-specific autonomy by conserving the overall complexity of the parental karyotype. We deduced from these results that cancers cause metastases by karyotypic variations and selection for rare metastatic subspecies. Further we asked whether metastases with multiple metastasis-specific aneusomies are assembled in one or multiple, sequential steps. Since (1) no stable karyotypic intermediates of metastases were observed in cancers here and previously by others, and (2) the karyotypic complexities of cancers are conserved in metastases, we concluded that metastases are generated from cancers in one step – like subspecies in conventional speciation. Conclusions We conclude that the risk of cancers to metastasize is proportional to the degree of cancer-specific aneuploidy, because aneuploidy catalyzes the generation of subspecies, including metastases, at aneuploidy-dependent rates. Since speciation by random chromosomal rearrangements and selection is unpredictable, the theory that metastases are karyotypic subspecies of cancers also explains Foulds’ rules, which hold that the origins of metastases are “abrupt” and that their phenotypes are “unpredictable.”
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Affiliation(s)
- Mathew Bloomfield
- Department of Molecular and Cell Biology; Donner Laboratory, University of California at Berkeley, Berkeley, CA 94720 USA ; Present address: Department of Natural Sciences and Mathematics, Dominican University of California, San Rafael, CA USA
| | - Peter Duesberg
- Department of Molecular and Cell Biology; Donner Laboratory, University of California at Berkeley, Berkeley, CA 94720 USA
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Reed K, Parissenti AM. The effect of ABCB1 genetic variants on chemotherapy response in HIV and cancer treatment. Pharmacogenomics 2012; 12:1465-83. [PMID: 22008050 DOI: 10.2217/pgs.11.84] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Despite their clearly distinct pathophysiologies, HIV and cancer are diseases whose response to chemotherapy treatment varies substantially amongst patients, in particular for those with prior drug exposure. This has been attributed, in part, to elevated expression of the ABCB1 drug transporter in some patients, which results in reduced drug accumulation in target tissues. Many mechanisms have been identified for this elevated expression of ABCB1, including variations in the sequence of the gene coding for the transporter (ABCB1). Over 50 SNPs within ABCB1 have been identified. Associations have been made between the presence of specific ABCB1 SNPs/haplotypes and both ABCB1 expression and the efficacy or toxicity of certain chemotherapy regimens. If these associations are strong and reproducibly demonstrated, then this would greatly aid in the development of individualized therapy regimes for specific cancer or HIV patients, based on their ABCB1 genotypes. This article highlights the significant recent progress made in this direction, but cautions that the utility of ABCB1 gene variants as biomarkers of chemotherapy drug response remains unclear to date.
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Affiliation(s)
- Kerry Reed
- Regional Cancer Program, Sudbury Regional Hospital, 41 Ramsey Lake Rd, Sudbury, Ontario, Canada
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Abstract
The divergence of new genes and proteins occurs through mutations that modulate protein function. However, mutations are pleiotropic and can have different effects on organismal fitness depending on the environment, as well as opposite effects on protein function and dosage. We review the pleiotropic effects of mutations. We discuss how they affect the evolution of gene and protein function, and how these complex mutational effects dictate the likelihood and mechanism of gene duplication and divergence. We propose several factors that can affect the divergence of new protein functions, including mutational trade-offs and hidden, or apparently neutral, variation.
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The temporal relationship between ABCB1 promoter hypomethylation, ABCB1 expression and acquisition of drug resistance. THE PHARMACOGENOMICS JOURNAL 2010; 10:489-504. [DOI: 10.1038/tpj.2010.1] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Calcagno AM, Ambudkar SV. Molecular mechanisms of drug resistance in single-step and multi-step drug-selected cancer cells. Methods Mol Biol 2010; 596:77-93. [PMID: 19949921 PMCID: PMC3099236 DOI: 10.1007/978-1-60761-416-6_5] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Multidrug resistance (MDR) remains one of the key determinants in chemotherapeutic success of cancer patients. Often, acquired resistance is mediated by the overexpression of ATP-binding cassette (ABC) drug transporters. To study the mechanisms involved in the MDR phenotype, investigators have generated a variety of in vitro cell culture models using both multi-step and single-step drug selections. Sublines produced from multi-step selections have led to the discovery of several crucial drug transporters including ABCB1, ABCC1, and ABCG2. Additionally, a number of mechanisms causing gene overexpression have been elucidated. To more closely mimic in vivo conditions, investigators have also established MDR sublines with single-step drug selections. Here, we examine some of the multi-step and single-step selected cell lines generated to elucidate the mechanisms involved in the development of MDR in cancer cells.
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Affiliation(s)
- Anna Maria Calcagno
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, NIH, DHHS, Bethesda, MD 20892, USA
| | - Suresh V. Ambudkar
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, NIH, DHHS, Bethesda, MD 20892, USA
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Boushaba K, Levine H, Hamilton MN. A mathematical feasibility argument for the use of aptamers in chemotherapy and imaging. Math Biosci 2009; 220:131-42. [PMID: 19540245 PMCID: PMC2792639 DOI: 10.1016/j.mbs.2009.05.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2009] [Revised: 05/07/2009] [Accepted: 05/26/2009] [Indexed: 10/20/2022]
Abstract
A challenge for drug design is to create molecules with optimal functions that also partition efficiently into the appropriate in vivo compartment(s). This is particularly true in cancer treatments because cancer cells upregulate their expression of multidrug resistance transporters, which necessitates a higher concentration of extracellular drug to promote sufficiently high intracellular concentrations for cell killing. Pharmacokinetics can be improved by ancillary molecules, such as cyclodextrins, that increase the effective concentrations of hydrophobic drugs in the blood by providing hydrophobic binding pockets. However, the extent to which the extracellular concentration of drug can be increased is limited. A second approach, different from the 'push' mechanism just discussed, is a 'pull' mechanism by which the effective intracellular concentrations of a drug is increased by a molecule with an affinity for the drug that is located inside the cell. Here we propose and give a proof in principle that intracellular RNA aptamers might perform this function. The mathematical model considers the following: Suppose I denotes a drug (inhibitor) that must be distributed spatially throughout a cell, but that tends to remain outside the cell due the transport properties of the cell membrane. Suppose that E, an enzyme that binds to I, is expressed by the cell and remains in the cell. It may be that the equilibrium E+I[right arrow over left arrow]{k(-1)k(1)}P is not sufficiently far enough to the right to drive enough free inhibitor into the cell to completely inhibit the enzyme. Here we evaluate the use of an intracellular aptamer with affinity for the inhibitor (I) to increase the efficiency of inhibitor transport across the cell membrane and thus drive the above equilibrium further to the right than would ordinarily be the case. We show that this outcome will occur if: (1) the aptamer neither binds too tightly nor too weakly to the inhibitor than the enzyme and (2) the aptamer is much more diffusible in the cell cytoplasm than the enzyme. Thus, we propose and show by simulation that an intracellular aptamer can be enlisted for an integrated approach to increasing inhibitor effectiveness and imaging aptamer-expressing cells.
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Affiliation(s)
- Khalid Boushaba
- Department of Mathematics, Iowa State University, Ames, IA 50011, USA.
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10
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Donnenberg VS, Meyer EM, Donnenberg AD. Measurement of multiple drug resistance transporter activity in putative cancer stem/progenitor cells. Methods Mol Biol 2009; 568:261-279. [PMID: 19582433 PMCID: PMC4165075 DOI: 10.1007/978-1-59745-280-9_17] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Multiple drug resistance, mediated by the expression and activity of ABC-transporters, is a major obstacle to antineoplastic therapy. Normal tissue stem cells and their malignant counterparts share MDR transporter activity as a major mechanism of self-protection. Although MDR activity is upregulated in response to substrate chemotherapeutic agents, it is also constitutively expressed on both normal tissue stem cells and a subset of tumor cells prior to the initiation of therapy, representing a built-in obstacle to therapeutic ratio. Constitutive and induced MDR activity can be detected in cellular subsets of disaggregated tissues, using the fluorescent substrates Rhodamine 123 and Hoechst 33342 for ABCB1 (also known as P-gp and MDR1) and ABCG2 (BCRP1). In this chapter, we will describe the complete procedure for the detection of MDR activity, including: (1) Preparing single-cell suspensions from tumor and normal tissue specimens; (2) An efficient method to perform cell surface marker staining on large numbers of cells; (3) Flow cytometer setup and controls; (4) Simultaneous measurement of Hoechst 33342 and Rhodamine123 transport; and (5) Data acquisition and analysis.
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Pierga JY, Reis-Filho JS, Cleator SJ, Dexter T, MacKay A, Simpson P, Fenwick K, Iravani M, Salter J, Hills M, Jones C, Ashworth A, Smith IE, Powles T, Dowsett M. Microarray-based comparative genomic hybridisation of breast cancer patients receiving neoadjuvant chemotherapy. Br J Cancer 2007; 96:341-51. [PMID: 17133270 PMCID: PMC2359992 DOI: 10.1038/sj.bjc.6603483] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2006] [Revised: 10/12/2006] [Accepted: 10/23/2006] [Indexed: 12/29/2022] Open
Abstract
We analysed the molecular genetic profiles of breast cancer samples before and after neoadjuvant chemotherapy with combination doxorubicin and cyclophosphamide (AC). DNA was obtained from microdissected frozen breast core biopsies from 44 patients before chemotherapy. Additional samples were obtained before the second course of chemotherapy (D21) and after the completion of the treatment (surgical specimens) in 17 and 21 patients, respectively. Microarray-based comparative genome hybridisation was performed using a platform containing approximately 5800 bacterial artificial chromosome clones (genome-wide resolution: 0.9 Mb). Analysis of the 44 pretreatment biopsies revealed that losses of 4p, 4q, 5q, 12q13.11-12q13.12, 17p11.2 and 17q11.2; and gains of 1p, 2p, 7q, 9p, 11q, 19p and 19q were significantly associated with oestrogen receptor negativity. 16q21-q22.1 losses were associated with lobular and 8q24 gains with ductal types. Losses of 5q33.3-q4 and 18p11.31 and gains of 6p25.1-p25.2 and Xp11.4 were associated with HER2 amplification. No correlations between DNA copy number changes and clinical response to AC were found. Microarray-based comparative genome hybridisation analysis of matched pretreatment and D21 biopsies failed to identify statistically significant differences, whereas a comparison between matched pretreatment and surgical samples revealed a statistically significant acquired copy number gain on 11p15.2-11p15.5. The modest chemotherapy-driven genomic changes, despite profound loss of cell numbers, suggest that there is little therapeutic selection of resistant non-modal cell lineages.
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Affiliation(s)
- J-Y Pierga
- Breakthrough Breast Cancer Research Center, The Institute of Cancer Research, London, SW3 6JB, UK
- Medical Oncology Department, Institut Curie, Paris, cedex 5, France
| | - J S Reis-Filho
- Breakthrough Breast Cancer Research Center, The Institute of Cancer Research, London, SW3 6JB, UK
| | - S J Cleator
- Breakthrough Breast Cancer Research Center, The Institute of Cancer Research, London, SW3 6JB, UK
| | - T Dexter
- Breakthrough Breast Cancer Research Center, The Institute of Cancer Research, London, SW3 6JB, UK
| | - A MacKay
- Breakthrough Breast Cancer Research Center, The Institute of Cancer Research, London, SW3 6JB, UK
| | - P Simpson
- Breakthrough Breast Cancer Research Center, The Institute of Cancer Research, London, SW3 6JB, UK
| | - K Fenwick
- Breakthrough Breast Cancer Research Center, The Institute of Cancer Research, London, SW3 6JB, UK
| | - M Iravani
- Breakthrough Breast Cancer Research Center, The Institute of Cancer Research, London, SW3 6JB, UK
| | - J Salter
- Academic Department of Biochemistry, Royal Marsden Hospital NHS Trust, Fulham Road, London, SW3 6JJ, UK
| | - M Hills
- Academic Department of Biochemistry, Royal Marsden Hospital NHS Trust, Fulham Road, London, SW3 6JJ, UK
| | - C Jones
- Section of Paediatric Oncology, Institute of Cancer Research, London, SM2 5NG, UK
| | - A Ashworth
- Breakthrough Breast Cancer Research Center, The Institute of Cancer Research, London, SW3 6JB, UK
| | - I E Smith
- Breast Cancer Unit, Royal Marsden Hospital, London, SW3 6JJ, UK
| | - T Powles
- Breast Cancer Unit, Royal Marsden Hospital, London, SW3 6JJ, UK
| | - M Dowsett
- Breakthrough Breast Cancer Research Center, The Institute of Cancer Research, London, SW3 6JB, UK
- Academic Department of Biochemistry, Royal Marsden Hospital NHS Trust, Fulham Road, London, SW3 6JJ, UK
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Donnenberg VS, Luketich JD, Landreneau RJ, DeLoia JA, Basse P, Donnenberg AD. Tumorigenic epithelial stem cells and their normal counterparts. ERNST SCHERING FOUNDATION SYMPOSIUM PROCEEDINGS 2007:245-63. [PMID: 17939305 DOI: 10.1007/2789_2007_054] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
ABC transporters are highly conserved and represent a major protective mechanism for barrier tissues as well as adult tissue stem cells. Emerging data support the existence of a cancer stem cell that shares features of tissue stem cells, including the ability to self-renew and undergo dysregulated differentiation. Here we show that a rare population of cells coexpressing MDR transporters and stem cell markers is a common feature across therapy-naive epithelial cancers as well as normal epithelial tissue. MDR+ and MDR- candidate tumor stem and progenitor populations were all capable of generating highly anaplastic transplantable human tumors in NOD/SCID. The finding that rare cells bearing stem cell markers and having intrinsic MDR expression and activity are already present within the tumorigenic compartment before treatment with cytotoxic agents is of critical importance to cancer therapy. Just as damaged normal epithelial tissues regenerate after chemotherapy by virtue of highly protected resting tissue stem cells, the existence of malignant counterparts in therapy-naive epithelial cancers suggests a common mechanism by which normal and tumor stem cells protect themselves against toxic injury.
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Affiliation(s)
- V S Donnenberg
- Hillman Cancer Research Pavilion, 5117 Centre Avenue, Suite 2.42, Pittsburgh, PA 15213, USA
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Wang YC, Juric D, Francisco B, Yu RX, Duran GE, Chen KG, Chen X, Sikic BI. Regional activation of chromosomal arm 7q with and without gene amplification in taxane-selected human ovarian cancer cell lines. Genes Chromosomes Cancer 2006; 45:365-74. [PMID: 16382445 DOI: 10.1002/gcc.20300] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Taxanes are important drugs in the treatment of ovarian and other cancers, but their efficacy is limited by intrinsic and acquired drug resistance. Expression of the multidrug transporter P-glycoprotein, encoded by the MDR1 (ABCB1) gene, is one of the causes of clinical drug resistance to taxanes. To study the mechanisms of MDR1 activation related to taxanes, we established 11 multidrug-resistant variants from six ovarian cancer cell lines by continuous exposure to either paclitaxel or docetaxel. We profiled gene expression and gene copy number alterations in these cell lines using cDNA microarrays and identified a cluster of genes coactivated with MDR1 in 7q21.11-13. Regional activation was evident in nine resistant variants displaying a coexpression pattern of up to 22 genes over an 8-Mb area, including SRI, MGC4175, CLDN12, CROT, and CDK6. In six of these variants, regional activation was driven by gene copy number alterations, with low-level gains or high-level amplifications spanning the involved region. However, three variants displayed regional increases in gene expression even without concomitant gene copy number changes. These results suggest that regional gene activation may be a fundamental mechanism for acquired drug resistance, with or without changes in gene dosage. In addition to numerical and structural chromosomal changes driven by genome instability in cancer cells, other mechanisms might be involved in MDR1 regional activation, such as chromatin remodeling and DNA or histone modifications of the 7q21 region.
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Affiliation(s)
- Yan C Wang
- Oncology Division, Department of Medicine, Stanford University School of Medicine, Stanford, California 94305, USA
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Li R, Hehlman R, Sachs R, Duesberg P. Chromosomal alterations cause the high rates and wide ranges of drug resistance in cancer cells. ACTA ACUST UNITED AC 2006; 163:44-56. [PMID: 16271955 DOI: 10.1016/j.cancergencyto.2005.05.003] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2004] [Revised: 04/30/2005] [Accepted: 05/02/2005] [Indexed: 11/30/2022]
Abstract
Conventional mutation-selection theories have failed to explain (i) how cancer cells become spontaneously resistant against cytotoxic drugs at rates of up to 10(-3) per cell generation, orders higher than gene mutation, even in cancer cells; (ii) why resistance far exceeds a challenging drug-a state termed multidrug resistance; (iii) why resistance is associated with chromosomal alterations and proportional to their numbers; and (iv) why resistance is totally dependent on aneuploidy. We propose here that cancer-specific aneuploidy generates drug resistance via chromosomal alterations. According to this mechanism, aneuploidy varies the numbers and structures of chromosomes automatically, because it corrupts the many teams of proteins that segregate, synthesize, and repair chromosomes. Aneuploidy is thus a steady source of chromosomal variation from which, in classical Darwinian terms, resistance-specific aneusomies are selected in the presence of chemotherapeutic drugs. Some of the thousands of unselected genes that hitchhike with resistance-specific aneusomies can thus generate multidrug resistance. To test this hypothesis, we determined the rates of chromosomal alterations in clonal cultures of human breast and colon cancer lines by dividing the fraction of nonclonal karyotypes by the number of generations of the clone. These rates were about 10(-2) per cell generation, orders higher than mutation. Chromosome numbers and structures were determined in metaphases hybridized with color-coded chromosome-specific DNA probes. Further, we tested puromycin-resistant subclones of these lines for resistance-specific aneusomies. Resistant subclones differed from parental lines in four to seven specific aneusomies, of which different subclones shared some. The degree of resistance was roughly proportional to the number of these aneusomies. Thus, aneuploidy is the primary cause of the high rates and wide ranges of drug resistance in cancer cells.
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Affiliation(s)
- Ruhong Li
- Department of Molecular and Cell Biology, Donner Laboratory, University of California, Berkeley, Berkeley, CA 94720, USA
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15
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Stordal B, Peters G, Davey R. Similar chromosomal changes in cisplatin and oxaliplatin-resistant sublines of the H69 SCLC cell line are not associated with platinum resistance. Genes Chromosomes Cancer 2006; 45:1094-105. [PMID: 16967470 DOI: 10.1002/gcc.20373] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Small cell lung cancer (SCLC) initially responds well to DNA damaging drugs such as cisplatin, however this is transitory as resistance normally develops. To investigate whether changes in chromosomal copy number caused by platinum drug treatment contributes to platinum resistance, we have analyzed H69 SCLC cells and two low-level platinum-resistant sublines, H69CIS200 and H69OX400, derived by cisplatin and oxaliplatin treatment, respectively. Affymetrix 10K SNP array showed that cisplatin and oxaliplatin have independently caused similar changes including loss of segments 6q21-qter and 13pter-13q.14.11 and duplication of chromosome 21. Interestingly, despite using equally cytotoxic doses of drug in the development of the cell lines, oxaliplatin caused three times more chromosomal changes than cisplatin. The resistant cell lines lose their resistant phenotype after 3 months of drug-free culture. The revertant cell lines, denoted H69CIS200-S and H69OX400-S, were also analyzed by Affymetrix array to determine if chromosomal changes associated with resistance remain after the resistant phenotype is lost. In the H69OX400-S many of the changes observed in the resistant cells were absent suggesting that they contributed to the resistant phenotype including: loss of 1q23.3-qter, 10q11.23, and 19q13.12-q13.2 and duplication of segments 6p21.2-p12.3, 16q12.1-16q13, 16q21-q23.1, and 19q12. However, out of the similar changes induced by cisplatin and oxaliplatin, both the loss of 6q21-qter and gain of 21 were still present in the H69CIS200-S and H69OX400-S cells. This suggests that cisplatin and oxaliplatin induced similar changes due to inherent vulnerabilities in the H69 cells rather than changes associated with platinum resistance.
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Affiliation(s)
- Britta Stordal
- Bill Walsh Cancer Research Laboratories, Royal North Shore Hospital, St Leonards, Sydney, NSW 2065, Australia
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16
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Chen KG, Wang YC, Schaner ME, Francisco B, Durán GE, Juric D, Huff LM, Padilla-Nash H, Ried T, Fojo T, Sikic BI. Genetic and Epigenetic Modeling of the Origins of Multidrug-Resistant Cells in a Human Sarcoma Cell Line. Cancer Res 2005; 65:9388-97. [PMID: 16230402 DOI: 10.1158/0008-5472.can-04-4133] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The origin of drug-resistant cells in human cancers has been a fundamental problem of cancer pharmacology. Two major contrasting hypotheses (genetics versus epigenetics) have been proposed to elucidate the mechanisms of acquired drug resistance. In this study, we answer these fundamental questions through investigation of the genetic and epigenetic pathways that control the origin of ABCB1 (MDR1) gene activation with acquired multidrug resistance in drug-sensitive human sarcoma (MES-SA cells). The genetic and epigenetic bases of this selected activation involve the initiation of transcription at a site 112 kb upstream of the ABCB1 proximal promoter (P1) in the drug-resistant cells. This activation was associated with a chromatin-remodeling process characterized by an increase in acetylated histone H3 within a 968-bp region 5' of the ABCB1 upstream promoter. These alterations provide both genetic and epigenetic susceptibility for ABCB1 expression in drug-resistant cells. Complete activation of the ABCB1 gene through the coding region was proposed by interactions of selected trans-alterations or epigenetic changes on the ABCB1 proximal promoter, which occurred during initial drug exposure. Thus, our data provide evidence for a major genomic alteration that changes the chromatin structure of the ABCB1 upstream promoter via acetylation of histone H3 initiating ABCB1 activation, further elucidating the genetic and epigenetic bases that determine chemotherapeutic response in drug-resistant derivatives of MES-SA cells.
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Affiliation(s)
- Kevin G Chen
- Division of Oncology, Department of Medicine and Program in Cancer Biology, Stanford University School of Medicine, Stanford, CA, USA.
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17
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Frey JE, Frey B, Forcioli D. Quantitative assessment of heteroplasmy levels in Senecio vulgaris chloroplast DNA. Genetica 2005; 123:255-61. [PMID: 15954496 DOI: 10.1007/s10709-004-3711-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Heteroplasmy in coding chloroplast DNA was only recently shown to occur and was so far not quantitatively assessed. We present a quantitative analysis of cpDNA heteroplasmy levels at a triazine-resistance determining site within and between individual Senecio vulgaris plants. Detectable levels of heteroplasmic haplotypes were observed in all tested plants. As expected, the levels of heteroplasmy vary greatly between plants. However, even within individual plants, the fraction of one haplotype may cover a range from below 1% to well over 90%. Our results suggest that heteroplasmy may be a common phenomenon in S. vulgaris. Possible consequences for molecular diagnostics of chloroplast encoded traits as well as evolutionary consequences of chloroplast heteroplasmy are discussed.
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Affiliation(s)
- Juerg E Frey
- Agroscope FAW Waedenswil, Department of Plant Protection, Molecular Diagnostics Laboratory, Swiss Federal Research Station for Horticulture, CH8820 Wädenswil, Switzerland.
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18
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Findling-Kagan S, Sivan H, Ostrovsky O, Nagler A, Galski H. Establishment and characterization of new cellular lymphoma model expressing transgenic human MDR1. Leuk Res 2005; 29:407-14. [PMID: 15725475 DOI: 10.1016/j.leukres.2004.09.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2004] [Accepted: 09/07/2004] [Indexed: 10/25/2022]
Abstract
Multidrug resistance (MDR) due to the expression of the MDR1 gene and its P-glycoprotein (Pgp) product is a major factor in the prognosis and clinical outcome of patients with refractory lymphomas and other malignancies. The aim of our study was to establish a lymphoma, cellular system where a de novo acquisition of multidrug resistance is specifically related to overexpression of a transgenic, human MDR1. A multidrug sensitive lymphoma cell line (LM1) was established from a sporadic T-cell lymphoma of BALB/c mouse and was transduced by a retroviral vector containing the human MDR1 cDNA. The resultant cell variant (LM1/MDR) was characterized in comparison to the parental LM1 cells. The LM1/MDR cell variant is cross-resistant to DOX, COL, ACT D and VBL. This cell variant expresses the human MDR1 and exhibits de novo functional Pgp activity that can be blocked by the Pgp-modulators VRP and KT-5720. The acquired MDR of LM1/MDR is not accompanied with gene amplification, alternative splicing or up-regulation of the murine endogenous mdr1a, mdr1b, mrp1, mrp2 and mrp3 transporter-genes. Therefore, the acquired MDR is, specifically, human MDR1-dependent as it has been found in malignant cells of most lymphoma patients. Moreover, this system can be used as a model to study MDR and the efficacy of drugs and modulators on malignant cells where human Pgp is a major factor of multidrug resistance.
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Affiliation(s)
- Sarah Findling-Kagan
- Laboratory of Molecular Immunobiology, Department of Hematology and Bone Marrow Transplantation, Chaim Sheba Medical Center, Tel Hashomer 52621, Israel
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