1
|
Flanders KC, Heger CD, Conway C, Tang B, Sato M, Dengler SL, Goldsmith PK, Hewitt SM, Wakefield LM. Brightfield proximity ligation assay reveals both canonical and mixed transforming growth factor-β/bone morphogenetic protein Smad signaling complexes in tissue sections. J Histochem Cytochem 2014; 62:846-63. [PMID: 25141865 PMCID: PMC4244299 DOI: 10.1369/0022155414550163] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 07/18/2014] [Indexed: 11/22/2022] Open
Abstract
Transforming growth factor-β (TGF-β) is an important regulator of cellular homeostasis and disease pathogenesis. Canonical TGF-β signaling occurs through Smad2/3-Smad4 complexes; however, recent in vitro studies suggest that elevated levels of TGF-β may activate a novel mixed Smad complex (Smad2/3-Smad1/5/9), which is required for some of the pro-oncogenic activities of TGF-β. To determine if mixed Smad complexes are evident in vivo, we developed antibodies that can be used with a proximity ligation assay to detect either canonical or mixed Smad complexes in formalin-fixed paraffin-embedded sections. We demonstrate high expression of mixed Smad complexes in the tissues from mice genetically engineered to express high levels of TGF-β1. Mixed Smad complexes were also prominent in 15-16 day gestation mouse embryos and in breast cancer xenografts, suggesting important roles in embryonic development and tumorigenesis. In contrast, mixed Smad complexes were expressed at extremely low levels in normal adult mouse tissue, where canonical complexes were correspondingly higher. We show that this methodology can be used in archival patient samples and tissue microarrays, and we have developed an algorithm to quantitate the brightfield read-out. These methods will allow quantitative analysis of cell type-specific Smad signaling pathways in physiological and pathological processes.
Collapse
Affiliation(s)
- Kathleen C Flanders
- Laboratory of Cancer Biology and Genetics (KCF, BT, MS, SLD, LMW), Center for Cancer Research, National Cancer Institute, Bethesda, MDAntibody and Protein Purification Unit (CDH, PKG), Center for Cancer Research, National Cancer Institute, Bethesda, MDLaboratory of Pathology (CC, SMH), Center for Cancer Research, National Cancer Institute, Bethesda, MD
| | - Christopher D Heger
- Laboratory of Cancer Biology and Genetics (KCF, BT, MS, SLD, LMW), Center for Cancer Research, National Cancer Institute, Bethesda, MDAntibody and Protein Purification Unit (CDH, PKG), Center for Cancer Research, National Cancer Institute, Bethesda, MDLaboratory of Pathology (CC, SMH), Center for Cancer Research, National Cancer Institute, Bethesda, MD
| | - Catherine Conway
- Laboratory of Cancer Biology and Genetics (KCF, BT, MS, SLD, LMW), Center for Cancer Research, National Cancer Institute, Bethesda, MDAntibody and Protein Purification Unit (CDH, PKG), Center for Cancer Research, National Cancer Institute, Bethesda, MDLaboratory of Pathology (CC, SMH), Center for Cancer Research, National Cancer Institute, Bethesda, MD
| | - Binwu Tang
- Laboratory of Cancer Biology and Genetics (KCF, BT, MS, SLD, LMW), Center for Cancer Research, National Cancer Institute, Bethesda, MDAntibody and Protein Purification Unit (CDH, PKG), Center for Cancer Research, National Cancer Institute, Bethesda, MDLaboratory of Pathology (CC, SMH), Center for Cancer Research, National Cancer Institute, Bethesda, MD
| | - Misako Sato
- Laboratory of Cancer Biology and Genetics (KCF, BT, MS, SLD, LMW), Center for Cancer Research, National Cancer Institute, Bethesda, MDAntibody and Protein Purification Unit (CDH, PKG), Center for Cancer Research, National Cancer Institute, Bethesda, MDLaboratory of Pathology (CC, SMH), Center for Cancer Research, National Cancer Institute, Bethesda, MD
| | - Samuel L Dengler
- Laboratory of Cancer Biology and Genetics (KCF, BT, MS, SLD, LMW), Center for Cancer Research, National Cancer Institute, Bethesda, MDAntibody and Protein Purification Unit (CDH, PKG), Center for Cancer Research, National Cancer Institute, Bethesda, MDLaboratory of Pathology (CC, SMH), Center for Cancer Research, National Cancer Institute, Bethesda, MD
| | - Paul K Goldsmith
- Laboratory of Cancer Biology and Genetics (KCF, BT, MS, SLD, LMW), Center for Cancer Research, National Cancer Institute, Bethesda, MDAntibody and Protein Purification Unit (CDH, PKG), Center for Cancer Research, National Cancer Institute, Bethesda, MDLaboratory of Pathology (CC, SMH), Center for Cancer Research, National Cancer Institute, Bethesda, MD
| | - Stephen M Hewitt
- Laboratory of Cancer Biology and Genetics (KCF, BT, MS, SLD, LMW), Center for Cancer Research, National Cancer Institute, Bethesda, MDAntibody and Protein Purification Unit (CDH, PKG), Center for Cancer Research, National Cancer Institute, Bethesda, MDLaboratory of Pathology (CC, SMH), Center for Cancer Research, National Cancer Institute, Bethesda, MD
| | - Lalage M Wakefield
- Laboratory of Cancer Biology and Genetics (KCF, BT, MS, SLD, LMW), Center for Cancer Research, National Cancer Institute, Bethesda, MDAntibody and Protein Purification Unit (CDH, PKG), Center for Cancer Research, National Cancer Institute, Bethesda, MDLaboratory of Pathology (CC, SMH), Center for Cancer Research, National Cancer Institute, Bethesda, MD
| |
Collapse
|
5
|
Ruggiero RA, Bustuoabad OD. The biological sense of cancer: a hypothesis. Theor Biol Med Model 2006; 3:43. [PMID: 17173673 PMCID: PMC1764731 DOI: 10.1186/1742-4682-3-43] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Accepted: 12/15/2006] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Most theories about cancer proposed during the last century share a common denominator: cancer is believed to be a biological nonsense for the organism in which it originates, since cancer cells are believed to be ones evading the rules that control normal cell proliferation and differentiation. In this essay, we have challenged this interpretation on the basis that, throughout the animal kingdom, cancer seems to arise only in injured organs and tissues that display lost or diminished regenerative ability. HYPOTHESIS According to our hypothesis, a tumor cell would be the only one able to respond to the demand to proliferate in the organ of origin. It would be surrounded by "normal" aged cells that cannot respond to that signal. According to this interpretation, cancer would have a profound biological sense: it would be the ultimate way to attempt to restore organ functions and structures that have been lost or altered by aging or noxious environmental agents. In this way, the features commonly associated with tumor cells could be reinterpreted as progressively acquired adaptations for responding to a permanent regenerative signal in the context of tissue injury. Analogously, several embryo developmental stages could be dependent on cellular damage and death, which together disrupt the field topography. However, unlike normal structures, cancer would have no physiological value, because the usually poor or non-functional nature of its cells would make their reparative task unattainable. CONCLUSION The hypothesis advanced in this essay might have significant practical implications. All conventional therapies against cancer attempt to kill all cancer cells. However, according to our hypothesis, the problem might not be solved even if all the tumor cells were eradicated. In effect, if the organ failure remained, new tumor cells would emerge and the tumor would reinitiate its progressive growth in response to the permanent regenerative signal of the non-restored organ. Therefore, efficient anti-cancer therapy should combine an attack against the tumor cells themselves with the correction of the organ failure, which, according to this hypothesis, is fundamental to the origin of the cancer.
Collapse
Affiliation(s)
- Raúl A Ruggiero
- División Medicina Experimental, Instituto de Investigaciones Hematológicas, Academia Nacional de Medicina de Buenos Aires, Pacheco de Melo 3081, 1425 Buenos Aires, Argentina
| | - Oscar D Bustuoabad
- División Medicina Experimental, Instituto de Investigaciones Hematológicas, Academia Nacional de Medicina de Buenos Aires, Pacheco de Melo 3081, 1425 Buenos Aires, Argentina
| |
Collapse
|
6
|
Hauptmann S, Schmitt WD. Transposable elements – Is there a link between evolution and cancer? Med Hypotheses 2006; 66:580-91. [PMID: 16239072 DOI: 10.1016/j.mehy.2005.08.051] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Accepted: 08/04/2005] [Indexed: 11/28/2022]
Abstract
Currently, the most predominant theory concerning the formation of cancer is that it is a genetic accident. Accordingly, various agents are thought to cause DNA damage which then subsequently activates oncogenes and inactivates tumor suppressor genes. This article, however, describes a theory that interprets cancer as a misguided adaptation. Stressors, which cannot be compensated for with the usual cell possibilities might arouse evolutionary mechanisms intended to create new protein variants. One of these is the activation of transposable elements which leads to a reformatting of the genome. The result of this process is either a cell that survives very well under stress (and will, therefore, never be detected), a dead cell (in case the process is ineffective), or a more or less abnormal and harmful cell that builds up a new but cancerous organ. This theory explains the complex genetic alterations which are present in almost all cancer cells. It also explains the action of non-mutagenic carcinogens. As part of the reformatting process of the cancer cell genome, activation of oncogenes and inactivation of tumor suppressor genes are not stochastic events but the result of an unlucky genomic composition.
Collapse
Affiliation(s)
- Steffen Hauptmann
- Institute of Pathology, Martin-Luther-University Halle-Wittenberg, Magdeburger Strasse 14, D-06097 Halle (Saale), Germany.
| | | |
Collapse
|
8
|
Abstract
Recent advances in molecular biology have raised the hope that understanding of human cancer might progress rapidly and that improvements in therapy might result (Bishop 1983a, b; Busch 1962; Busch 1976; Duesberg 1983). With the development of gene cloning, DNA sequence analysis and improved hybridization methods, it became possible to evaluate whether cancer results from alteration in gene dosage, point or multiple mutation of genes, translocations, deletions, insertions, inversions, cis or trans altered promoters, amplification, and a variety of other genetic factors, including enhancer elements that alter rates of readouts of particular mRNA species. "Onc genes" are under intensive study because they offer manageable probes for evaluation of these various possibilities and also because the study of their cellular analogs may further understanding of the molecular biology of normal fetal and malignant cells. Despite the excessive enthusiasm of some proponents of this field and the negativism of its critics (Bishop 1983 a, b; Duesberg 1983), it is clear that analytical tools and new information will be of value in further studies on experimental cancer, regardless of whether cellular oncogenes (c-onc genes) have anything to do with human cancer or not. In the meantime, studies on enzymes, proteins and epitopes involved in growth processes, have opened new avenues for inhibition of human cancer by quantitative reduction of biosynthetic reactions.
Collapse
|