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Meng Y, Huang K, Shi M, Huo Y, Han L, Liu B, Li Y. Research Advances in the Role of the Tropomyosin Family in Cancer. Int J Mol Sci 2023; 24:13295. [PMID: 37686101 PMCID: PMC10488083 DOI: 10.3390/ijms241713295] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 08/22/2023] [Accepted: 08/24/2023] [Indexed: 09/10/2023] Open
Abstract
Cancer is one of the most difficult diseases for human beings to overcome. Its development is closely related to a variety of factors, and its specific mechanisms have been a hot research topic in the field of scientific research. The tropomyosin family (Tpm) is a group of proteins closely related to the cytoskeleton and actin, and recent studies have shown that they play an important role in various cancers, participating in a variety of biological activities, including cell proliferation, invasion, and migration, and have been used as biomarkers for various cancers. The purpose of this review is to explore the research progress of the Tpm family in tumorigenesis development, focusing on the molecular pathways associated with them and their relevant activities involved in tumors. PubMed and Web of Science databases were searched for relevant studies on the role of Tpms in tumorigenesis and development and the activities of Tpms involved in tumors. Data from the literature suggest that the Tpm family is involved in tumor cell proliferation and growth, tumor cell invasion and migration, tumor angiogenesis, tumor cell apoptosis, and immune infiltration of the tumor microenvironment, among other correlations. It can be used as a potential biomarker for early diagnosis, follow-up, and therapeutic response of some tumors. The Tpm family is involved in cancer in a close relationship with miRNAs and LncRNAs. Tpms are involved in tumor tissue invasion and migration as a key link. On this basis, TPM is frequently used as a biomarker for various cancers. However, the specific molecular mechanism of its involvement in cancer progression has not been explained clearly, which remains an important direction for future research.
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Affiliation(s)
- Yucheng Meng
- Key Laboratory of Dental Maxillofacial Reconstruction and Biological Intelligence Manufacturing, School of Stomatology, Lanzhou University, Lanzhou 730030, China; (Y.M.); (K.H.); (M.S.); (Y.H.); (L.H.)
| | - Ke Huang
- Key Laboratory of Dental Maxillofacial Reconstruction and Biological Intelligence Manufacturing, School of Stomatology, Lanzhou University, Lanzhou 730030, China; (Y.M.); (K.H.); (M.S.); (Y.H.); (L.H.)
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730030, China
| | - Mingxuan Shi
- Key Laboratory of Dental Maxillofacial Reconstruction and Biological Intelligence Manufacturing, School of Stomatology, Lanzhou University, Lanzhou 730030, China; (Y.M.); (K.H.); (M.S.); (Y.H.); (L.H.)
| | - Yifei Huo
- Key Laboratory of Dental Maxillofacial Reconstruction and Biological Intelligence Manufacturing, School of Stomatology, Lanzhou University, Lanzhou 730030, China; (Y.M.); (K.H.); (M.S.); (Y.H.); (L.H.)
| | - Liang Han
- Key Laboratory of Dental Maxillofacial Reconstruction and Biological Intelligence Manufacturing, School of Stomatology, Lanzhou University, Lanzhou 730030, China; (Y.M.); (K.H.); (M.S.); (Y.H.); (L.H.)
| | - Bin Liu
- Key Laboratory of Dental Maxillofacial Reconstruction and Biological Intelligence Manufacturing, School of Stomatology, Lanzhou University, Lanzhou 730030, China; (Y.M.); (K.H.); (M.S.); (Y.H.); (L.H.)
| | - Yi Li
- Key Laboratory of Dental Maxillofacial Reconstruction and Biological Intelligence Manufacturing, School of Stomatology, Lanzhou University, Lanzhou 730030, China; (Y.M.); (K.H.); (M.S.); (Y.H.); (L.H.)
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Takenawa T, Harada K, Ferdous T, Kawasaki K, Kuramitsu Y, Mishima K. Silencing of Tropomyosin 1 suppresses the proliferation, invasion and metastasis of oral squamous cell carcinoma in vitro. JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY, MEDICINE, AND PATHOLOGY 2022. [DOI: 10.1016/j.ajoms.2022.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Grundy TJ, Orcheston-Findlay L, de Silva E, Jegathees T, Prior V, Sarker FA, O'Neill GM. Mechanosensitive expression of the mesenchymal subtype marker connective tissue growth factor in glioblastoma. Sci Rep 2022; 12:14982. [PMID: 36056123 PMCID: PMC9440209 DOI: 10.1038/s41598-022-19175-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 08/25/2022] [Indexed: 12/05/2022] Open
Abstract
Mechanical forces created by the extracellular environment regulate biochemical signals that modulate the inter-related cellular phenotypes of morphology, proliferation, and migration. A stiff microenvironment induces glioblastoma (GBM) cells to develop prominent actin stress fibres, take on a spread morphology and adopt trapezoid shapes, when cultured in 2D, which are phenotypes characteristic of a mesenchymal cell program. The mesenchymal subtype is the most aggressive among the molecular GBM subtypes. Recurrent GBM have been reported to transition to mesenchymal. We therefore sought to test the hypothesis that stiffer microenvironments-such as those found in different brain anatomical structures and induced following treatment-contribute to the expression of markers characterising the mesenchymal subtype. We cultured primary patient-derived cell lines that reflect the three common GBM subtypes (mesenchymal, proneural and classical) on polyacrylamide (PA) hydrogels with controlled stiffnesses spanning the healthy and pathological tissue range. We then assessed the canonical mesenchymal markers Connective Tissue Growth Factor (CTGF) and yes-associated protein (YAP)/transcriptional co-activator with PDZ-binding motif (TAZ) expression, via immunofluorescence. Replating techniques and drug-mediated manipulation of the actin cytoskeleton were utilised to ascertain the response of the cells to differing mechanical environments. We demonstrate that CTGF is induced rapidly following adhesion to a rigid substrate and is independent of actin filament formation. Collectively, our data suggest that microenvironmental rigidity can stimulate expression of mesenchymal-associated molecules in GBM.
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Affiliation(s)
- Thomas James Grundy
- Children's Cancer Research Unit, Kids Research Institute at the Children's Hospital at Westmead, Westmead, NSW, 2145, Australia
| | - Louise Orcheston-Findlay
- Children's Cancer Research Unit, Kids Research Institute at the Children's Hospital at Westmead, Westmead, NSW, 2145, Australia
| | - Eshana de Silva
- Children's Cancer Research Unit, Kids Research Institute at the Children's Hospital at Westmead, Westmead, NSW, 2145, Australia
| | - Thuvarahan Jegathees
- Children's Cancer Research Unit, Kids Research Institute at the Children's Hospital at Westmead, Westmead, NSW, 2145, Australia
- Children's Hospital Westmead Clinical School, Faculty of Medicine and Health, University of Sydney, Sydney, 2006, Australia
| | - Victoria Prior
- Children's Cancer Research Unit, Kids Research Institute at the Children's Hospital at Westmead, Westmead, NSW, 2145, Australia
- Children's Hospital Westmead Clinical School, Faculty of Medicine and Health, University of Sydney, Sydney, 2006, Australia
| | - Farhana Amy Sarker
- Children's Cancer Research Unit, Kids Research Institute at the Children's Hospital at Westmead, Westmead, NSW, 2145, Australia
- Children's Hospital Westmead Clinical School, Faculty of Medicine and Health, University of Sydney, Sydney, 2006, Australia
| | - Geraldine Margaret O'Neill
- Children's Cancer Research Unit, Kids Research Institute at the Children's Hospital at Westmead, Westmead, NSW, 2145, Australia.
- Children's Hospital Westmead Clinical School, Faculty of Medicine and Health, University of Sydney, Sydney, 2006, Australia.
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Suresh R, Diaz RJ. The remodelling of actin composition as a hallmark of cancer. Transl Oncol 2021; 14:101051. [PMID: 33761369 PMCID: PMC8008238 DOI: 10.1016/j.tranon.2021.101051] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 02/01/2021] [Accepted: 02/17/2021] [Indexed: 02/06/2023] Open
Abstract
Actin is a key structural protein that makes up the cytoskeleton of cells, and plays a role in functions such as division, migration, and vesicle trafficking. It comprises six different cell-type specific isoforms: ACTA1, ACTA2, ACTB, ACTC1, ACTG1, and ACTG2. Abnormal actin isoform expression has been reported in many cancers, which led us to hypothesize that it may serve as an early biomarker of cancer. We show an overview of the different actin isoforms and highlight mechanisms by which they may contribute to tumorigenicity. Furthermore, we suggest how the aberrant expression of actin subunits can confer cells with greater proliferation ability, increased migratory capability, and chemoresistance through incorporation into the normal cellular F-actin network and altered actin binding protein interaction. Studying this fundamental change that takes place within cancer cells can further our understanding of neoplastic transformation in multiple tissue types, which can ultimately aid in the early-detection, diagnosis and treatment of cancer.
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Affiliation(s)
- Rahul Suresh
- Montreal Neurological Institute, Integrated Program in Neuroscience, McGill University, Montreal, Canada
| | - Roberto J Diaz
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, Faculty of Medicine, McGill University, Montreal, Canada.
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Tropomyosin Tpm 2.1 loss induces glioblastoma spreading in soft brain-like environments. J Neurooncol 2018; 141:303-313. [PMID: 30535593 DOI: 10.1007/s11060-018-03049-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 11/12/2018] [Indexed: 12/25/2022]
Abstract
INTRODUCTION The brain is a very soft tissue. Glioblastoma (GBM) brain tumours are highly infiltrative into the surrounding healthy brain tissue and invasion mechanisms that have been defined using rigid substrates therefore may not apply to GBM dissemination. GBMs characteristically lose expression of the high molecular weight tropomyosins, a class of actin-associating proteins and essential regulators of the actin stress fibres and focal adhesions that underpin cell migration on rigid substrates. METHODS Here, we investigated how loss of the high molecular weight tropomyosins affects GBM on soft matrices that recapitulate the biomechanical architecture of the brain. RESULTS We find that Tpm 2.1 is down-regulated in GBM grown on soft substrates. We demonstrate that Tpm 2.1 depletion by siRNA induces cell spreading and elongation in soft 3D hydrogels, irrespective of matrix composition. Tpm 1.7, a second high molecular weight tropomyosin is also down-regulated when cells are cultured on soft brain-like surfaces and we show that effects of this isoform are matrix dependent, with Tpm 1.7 inducing cell rounding in 3D collagen gels. Finally, we show that the absence of Tpm 2.1 from primary patient-derived GBMs correlates with elongated, mesenchymal invasion. CONCLUSIONS We propose that Tpm 2.1 down-regulation facilitates GBM colonisation of the soft brain environment. This specialisation of the GBM actin cytoskeleton organisation that is highly suited to the soft brain-like environment may provide novel therapeutic targets for arresting GBM invasion.
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Chen Y, Hong Z, Lu S, Zhang N, Rong G, Chang X, Liu Z, Bai W, Dong Z, Gao X, Zeng Z, Lu Y. Downregulated Expression of Tropomyosin 1 in Intrahepatic Cholangiocarcinoma: A Predictor of Recurrence and Prognosis. Med Sci Monit 2018; 24:7875-7882. [PMID: 30390420 PMCID: PMC6231322 DOI: 10.12659/msm.907340] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Background The downregulation of tropomyosin 1 (TPM1) has been observed in various tumors, but few studies have focused on the clinical significance of TPM1 in intrahepatic cholangiocarcinoma (ICC). In the present study, we investigated the prognostic significance of TPM1 in ICC. Material/Methods A total of 124 patients with ICC were enrolled in this study. Quantitative real-time polymerase chain reaction (qRT-RCR) was performed to examine the mRNA levels of TPM1 in ICC tissue samples and adjacent noncancerous tissue specimens, while the protein level of TPM1 in tissue specimens were investigated using immunohistochemistry assay. The correlation of TPM1 with clinicopathological features of ICC was analyzed by chi-square test. Survival analysis was performed with Kaplan-Meier method. The Cox proportional hazards model was used to evaluate the prognostic value of TPM1 in patients with ICC. Results TPM1 expression was significantly downregulated in ICC tissues at mRNA and protein levels (P<0.001 for both). Downregulated TPM1 mRNA was negatively associated with tumor size (P=0.001) and TNM stage (P=0.007). Moreover, survival analysis demonstrated that patients with low TPM1 expression had a shorter overall survival (OS) (P<0.001) and recurrence-free survival (RFS) (P<0.001) than those with high TPM1 expression. Additionally, multivariate analysis showed that TPM1 could be a potential biomarker for predicting the recurrence (HR=4.632, 95% CI: 3.832–10.368, P<0.001) and survival outcome (HR=5.320, 95% CI: 2.627–11.776, P<0.001) of ICC. Conclusions TPM1 may serve as a useful biomarker for predicting tumor recurrence and prognosis in patients with ICC.
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Affiliation(s)
- Yan Chen
- Comprehensive Liver Cancer Center, Beijing 302 Hospital, Beijing, China (mainland)
| | - Zhixian Hong
- Department of Hepatobiliary Surgery, Beijing 302 Hospital, Beijing, China (mainland)
| | - Shanshan Lu
- Comprehensive Liver Cancer Center, Beijing 302 Hospital, Beijing, China (mainland)
| | - Ning Zhang
- Department of Integrated Traditional Chinese Medicine (TCM) and Western Medicine, Beijing 302 Hospital, Beijing, China (mainland)
| | - Guanghua Rong
- Comprehensive Liver Cancer Center, Beijing 302 Hospital, Beijing, China (mainland)
| | - Xiujuan Chang
- Comprehensive Liver Cancer Center, Beijing 302 Hospital, Beijing, China (mainland)
| | - Ze Liu
- Comprehensive Liver Cancer Center, Beijing 302 Hospital, Beijing, China (mainland)
| | - Wenlin Bai
- Comprehensive Liver Cancer Center, Beijing 302 Hospital, Beijing, China (mainland)
| | - Zheng Dong
- Comprehensive Liver Cancer Center, Beijing 302 Hospital, Beijing, China (mainland)
| | - Xudong Gao
- Comprehensive Liver Cancer Center, Beijing 302 Hospital, Beijing, China (mainland)
| | - Zhen Zeng
- Comprehensive Liver Cancer Center, Beijing 302 Hospital, Beijing, China (mainland)
| | - Yinying Lu
- Comprehensive Liver Cancer Center, Beijing 302 Hospital, Beijing, China (mainland)
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Zare M, Hadi F, Alivand MR. Considering the downregulation of Tpm1.6 and Tpm1.7 in squamous cell carcinoma of esophagus as a potent biomarker. Per Med 2018; 15:361-370. [PMID: 30259780 DOI: 10.2217/pme-2018-0015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
AIM Squamous cell carcinoma of esophagus (SCCE) is an aggressive disease with a poor prognosis. Tropomyosins attach to actin microfilaments, providing its stability. Nonmuscle cells express Tpm isoforms such as Tpm1.6 and Tpm1.7 which are involved in cytoskeleton functional properties regulation. MATERIALS & METHODS The expression of Tpm1.6 and Tpm1.7 was analyzed in SCCE tissues and its association with clinicopathological parameters and survival of patients was assessed. RESULTS Tpm1.6 and Tpm1.7, besides TPM1 mRNA decreased considerably in SCCE tissues relative to normal esophageal tissues (p < 0.001). TPM1 downregulation level was significantly associated with the degree of tumor differentiation (p = 0.017). CONCLUSION Tpm1.6 and Tpm1.7 suppression play a crucial role in esophagus tumorigenesis and could be associated with SCCE poor prognosis.
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Affiliation(s)
- Maryam Zare
- Department of Biology, Faculty of Sciences, Payame Noor University, Tehran, Iran
| | - Faranak Hadi
- Department of Biology, Faculty of Sciences, Lorestan University, Khorramabad, Iran
| | - Mohammad Reza Alivand
- Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
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Mitchell CB, Stehn JR, O'Neill GM. Small molecule targeting of the actin associating protein tropomyosin Tpm3.1 increases neuroblastoma cell response to inhibition of Rac‐mediated multicellular invasion. Cytoskeleton (Hoboken) 2018; 75:307-317. [DOI: 10.1002/cm.21452] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2017] [Revised: 05/07/2018] [Accepted: 05/07/2018] [Indexed: 01/16/2023]
Affiliation(s)
- Camilla B. Mitchell
- Children's Cancer Research UnitKids Research Institute, The Children's Hospital at WestmeadWestmead New South Wales Australia
| | - Justine R. Stehn
- Novogen Pty LtdHornsby NSW Australia
- School of Medical SciencesUniversity of New South Wales AustraliaSydney NSW Australia
| | - Geraldine M. O'Neill
- Children's Cancer Research UnitKids Research Institute, The Children's Hospital at WestmeadWestmead New South Wales Australia
- Discipline of Paediatrics and Child HealthThe University of SydneySydney New South Wales Australia
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Tang C, Wang J, Wei Q, Du YP, Qiu HP, Yang C, Hou YC. Tropomyosin-1 promotes cancer cell apoptosis via the p53-mediated mitochondrial pathway in renal cell carcinoma. Oncol Lett 2018; 15:7060-7068. [PMID: 29731872 PMCID: PMC5921034 DOI: 10.3892/ol.2018.8204] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 01/10/2018] [Indexed: 01/07/2023] Open
Abstract
Tropomyosin-1 (TPM1), a widely expressed actin-binding protein, is downregulated in many tumors and associated with cancer progression. A previous study from our group suggested that TPM1 could be involved in renal cell carcinoma (RCC) apoptosis, but the mechanisms and details remained unknown. The present study aimed to further examine the proapoptotic effects of TPM1 and investigate the underlying mechanisms in RCC cell lines. Results from cell viability, DAPI staining and apoptosis assays demonstrated that TPM1 upregulation inhibited cell proliferation and promoted cell apoptosis in both 786-O and ACHN RCC cell lines. However, TPM1 knockdown in the two RCC cell lines did not result in the opposite effects on cell proliferation or cell apoptosis. Comet assay and western blotting results demonstrated that TPM1 overexpression induced DNA damage and decreased the expression levels of the antiapoptotic factor BCL2 apoptosis regulator, while increasing the expression levels of the proapoptotic factors BCL2 associated X, Caspase-3 and p53 in 786-O and ACHN cells. The present findings suggest that TPM1 overexpression in RCC cell lines can induce tumor cell apoptosis via the p53-mediated mitochondrial pathway. Further studies are needed to fully elucidate the potential of TPM1 as a candidate for RCC targeted therapy in the future.
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Affiliation(s)
- Chao Tang
- Department of Urology, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Jin Wang
- Department of Urology, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Qi Wei
- Department of Anesthesiology, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Yi-Peng Du
- Department of Anesthesiology, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - He-Ping Qiu
- Department of Urology, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Chao Yang
- Department of Urology, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Yu-Chuan Hou
- Department of Urology, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
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Coombes JD, Schevzov G, Kan CY, Petti C, Maritz MF, Whittaker S, Mackenzie KL, Gunning PW. Ras Transformation Overrides a Proliferation Defect Induced by Tpm3.1 Knockout. Cell Mol Biol Lett 2016; 20:626-46. [PMID: 26274783 DOI: 10.1515/cmble-2015-0037] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 07/30/2015] [Indexed: 12/16/2022] Open
Abstract
Extensive re-organisation of the actin cytoskeleton and changes in the expression of its binding proteins is a characteristic feature of cancer cells. Previously we have shown that the tropomyosin isoform Tpm3.1, an integral component of the actin cytoskeleton in tumor cells, is required for tumor cell survival. Our objective was to determine whether cancer cells devoid of Tpm3.1 would evade the tumorgenic effects induced by H-Ras transformation. The tropomyosin isoform (Tpm) expression profile of a range of cancer cell lines (21) demonstrates that Tpm3.1 is one of the most broadly expressed Tpm isoform. Consequently, the contribution of Tpm3.1 to the transformation process was functionally evaluated. Primary embryonic fibroblasts isolated from wild type (WT) and Tpm3.1 knockout (KO) mice were transduced with retroviral vectors expressing SV40 large T antigen and an oncogenic allele of the H-Ras gene, H-RasV12, to generate immortalized and transformed WT and KO MEFs respectively. We show that Tpm3.1 is required for growth factor-independent proliferation in the SV40 large T antigen immortalized MEFs, but this requirement is overcome by H-Ras transformation. Consistent with those findings, we found that Tpm3.1 was not required for anchorage independent growth or growth of H-Ras-driven tumors in a mouse model. Finally, we show that pERK and Importin 7 protein interactions are significantly decreased in the SV40 large T antigen immortalized KO MEFs but not in the H-Ras transformed KO cells, relative to control MEFs. The data demonstrate that H-Ras transformation overrides a requirement for Tpm3.1 in growth factor-independent proliferation of immortalized MEFs. We propose that in the SV40 large T antigen immortalized MEFs, Tpm3.1 is partly responsible for the efficient interaction between pERK and Imp7 resulting in cell proliferation, but this is overidden by Ras transformation.
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Schevzov G, Vrhovski B, Bryce NS, Elmir S, Qiu MR, O'neill GM, Yang N, Verrills NM, Kavallaris M, Gunning PW. Tissue-specific Tropomyosin Isoform Composition. J Histochem Cytochem 2016; 53:557-70. [PMID: 15872049 DOI: 10.1369/jhc.4a6505.2005] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Four distinct genes encode tropomyosin (Tm) proteins, integral components of the actin microfilament system. In non-muscle cells, over 40 Tm isoforms are derived using alternative splicing. Distinct populations of actin filaments characterized by the composition of these Tm isoforms are found differentially sorted within cells ( Gunning et al. 1998b ). We hypothesized that these distinct intracellular compartments defined by the association of Tm isoforms may allow for independent regulation of microfilament function. Consequently, to understand the molecular mechanisms that give rise to these different microfilaments and their regulation, a cohort of fully characterized isoform-specific Tm antibodies was required. The characterization protocol initially involved testing the specificity of the antibodies on bacterially produced Tm proteins. We then confirmed that these Tm antibodies can be used to probe the expression and subcellular localization of different Tm isoforms by Western blot analysis, immunofluorescence staining of cells in culture, and immunohistochemistry of paraffin wax-embedded mouse tissues. These Tm antibodies, therefore, have the capacity to monitor specific actin filament populations in a range of experimental systems.
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Affiliation(s)
- Galina Schevzov
- Oncology Research Unit, The Children's Hospital at Westmead, Locked Bag 4001, Westmead, NSW, Sydney, Australia
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Huang QX, Cui JY, Ma H, Jia XM, Huang FL, Jiang LX. Screening of potential biomarkers for cholangiocarcinoma by integrated analysis of microarray data sets. Cancer Gene Ther 2016; 23:48-53. [PMID: 26679756 DOI: 10.1038/cgt.2015.66] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 11/19/2015] [Accepted: 11/23/2015] [Indexed: 12/12/2022]
Abstract
Cholangiocarcinoma (CCA) continues to harbor a difficult prognosis and it is difficult to diagnose in its early stages. The molecular mechanisms of CCA oncogenesis and progression are poorly understood. This study aimed to identify candidate biomarkers for CCA. Integrated analysis of microarray data sets was performed to identify differentially expressed genes (DEGs) between CCA and normal tissues. Gene Ontology enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were then performed to identify the functions of DEGs. Furthermore, the protein-protein interaction (PPI) network of DEGs was constructed. The expressions of DEGs were validated in human CCA tissues by qRT-PCR. A set of 712 DEGs were identified in CCA compared with normal tissues, including 306 upregulated and 406 downregulated DEGs. It can be shown from the KEGG pathway analysis that some pathways may have important roles in pathology of CCA, including peroxisome proliferator-activated receptor signaling pathway, bile secretion, cell cycle, fat digestion and absorption. PPI network indicated that the significant hub proteins were PKM, SPP1 and TPM1. The abnormally overexpression PKM, SPP1 and TPM1 were closely related to oncogenesis and progression of CCA. PKM, SPP1, TPM1, COL1A1 and COL1A2 may serve as candidate biomarkers for diagnosis and prognosis of CCA.
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Affiliation(s)
- Q-X Huang
- Department of Gastrointestinal Surgery, Yantai Yuhuangding Hospital, Yantai, Shan Dong Province, China
| | - J-Y Cui
- Department of General Surgery, Qingdao Municipal Hospital, Qingdao, Shan Dong Province, China
| | - H Ma
- Department of General Surgery, Qingdao Municipal Hospital, Qingdao, Shan Dong Province, China
| | - X-M Jia
- Department of Gastrointestinal Surgery, Yantai Yuhuangding Hospital, Yantai, Shan Dong Province, China
| | - F-L Huang
- Department of Gastrointestinal Surgery, Yantai Yuhuangding Hospital, Yantai, Shan Dong Province, China
| | - L-X Jiang
- Department of Gastrointestinal Surgery, Yantai Yuhuangding Hospital, Yantai, Shan Dong Province, China
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Du HQ, Wang Y, Jiang Y, Wang CH, Zhou T, Liu HY, Xiao H. Silencing of the TPM1 gene induces radioresistance of glioma U251 cells. Oncol Rep 2015; 33:2807-14. [PMID: 25873252 DOI: 10.3892/or.2015.3906] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Accepted: 02/27/2015] [Indexed: 11/06/2022] Open
Abstract
The present study was designed to investigate the relationship between tropomyosin 1 (TPM1) and radioresistance in human U251 cells. Radioresistant U251 (RR-U251) cells were established by repeated small irradiating injury. TPM1 levels in the U251 and RR-U251 cells were inhibited by transfection with TPM1-short hairpin RNA (shRNA) while overexpression was induced by treatment with pcDNA3.1‑TPM1. The radiosensitivity of the U251 and RR-U251 cells and the plasmid-transfected cells was evaluated by cell viability, migration and invasion assays. Cell apoptosis was also examined in vitro. The radiosensitivity of U251 xenografts was observed by tumor growth curve after radiotherapy in an in vivo experiment. Western blotting and immunohistochemistry were used to detect the level of TPM1 in vivo. The expression of TPM1 was significantly decreased in the RR-U251 cells, which may be correlated with the radioresistance of the glioma U251 cells. In the TPM1-silenced RR-U251 and TPM1-silenced U251 cells, cell viability, migration and invasion ability were significantly increased, and the rate of cell apoptosis was decreased. Consistent with these results, in the TPM1-overexpressing U251 and RR-U251 cells, cell viability, migration and invasion abilities were markedly decreased, and increased apoptosis was noted when compared to the control group. Tumor growth of the U251 xenografts was significantly inhibited following treatment with pcDNA3.1‑TPM1 combined with radiotherapy. Taken together, these results indicate that TPM1 may be one mechanism underlying radiation resistance, and TPM1 may be a potential target for overcoming the radiation resistance in glioma.
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Affiliation(s)
- Hua-Qing Du
- Department of Neuro-Psychiatric Institute, Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Ying Wang
- Department of Neuro-Psychiatric Institute, Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Yao Jiang
- Department of Neuro-Psychiatric Institute, Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Chen-Han Wang
- Department of Neuro-Psychiatric Institute, Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Tao Zhou
- Department of Neuro-Psychiatric Institute, Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Hong-Yi Liu
- Department of Neuro-Psychiatric Institute, Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Hong Xiao
- Department of Neuro-Psychiatric Institute, Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
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Abdolahad M, Saeidi A, Janmaleki M, Mashinchian O, Taghinejad M, Taghinejad H, Azimi S, Mahmoudi M, Mohajerzadeh S. A single-cell correlative nanoelectromechanosensing approach to detect cancerous transformation: monitoring the function of F-actin microfilaments in the modulation of the ion channel activity. NANOSCALE 2015; 7:1879-1887. [PMID: 25524888 DOI: 10.1039/c4nr06102k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Cancerous transformation may be dependent on correlation between electrical disruptions in the cell membrane and mechanical disruptions of cytoskeleton structures. Silicon nanotube (SiNT)-based electrical probes, as ultra-accurate signal recorders with subcellular resolution, may create many opportunities for fundamental biological research and biomedical applications. Here, we used this technology to electrically monitor cellular mechanosensing. The SiNT probe was combined with an electrically activated glass micropipette aspiration system to achieve a new cancer diagnostic technique that is based on real-time correlation between mechanical and electrical behaviour of single cells. Our studies demonstrated marked changes in the electrical response following increases in the mechanical aspiration force in healthy cells. In contrast, such responses were extremely weak for malignant cells. Confocal microscopy results showed the impact of actin microfilament remodelling on the reduction of the electrical response for aspirated cancer cells due to the significant role of actin in modulating the ion channel activity in the cell membrane.
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Affiliation(s)
- Mohammad Abdolahad
- Nanoelectronic Center of Excellence, Thin Film and Nanoelectronic Lab, School of Electrical and Computer Engineering, University of Tehran, P.O. Box 14395/515, Tehran, Iran
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15
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Wang J, Guan J, Lu Z, Jin J, Cai Y, Wang C, Wang F. Clinical and tumor significance of tropomyosin-1 expression levels in renal cell carcinoma. Oncol Rep 2015; 33:1326-34. [PMID: 25607530 DOI: 10.3892/or.2015.3733] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 11/28/2014] [Indexed: 11/06/2022] Open
Abstract
Renal cell carcinoma (RCC) is the most common type of kidney cancer in adults and has been described as one of the deadliest of cancers affecting the genitourinary tract. Tropomyosin is a two-stranded α-helical coiled coil protein found in cell cytoskeletons. One of its isoforms, tropomyosin-1 (TPM1) has been reported as a novel tumor-suppressor gene and is downregulated in many solid tumors. However the expression level and function of TPM1 in RCC have not yet been determined. In the present study, we evaluated the TPM1-4 mRNA and TPM1 protein levels in RCC tissue samples. TPM1-overexpressing OSRC-2 and 786-O cell lines were also used to investigate the impact of TPM1 on RCC cells. We found that TPM1 was significantly and specifically downregulated in the RCC tissues. TPM1 expression was associated with tumor size, smoking status, Fuhrman grade and the prognosis of RCC patients. After TPM1 transfection, the migratory and invasive abilities of the OSRC-2 and 786-O cell lines were both reduced when compared to the control groups. Meanwhile, apoptosis was also enhanced in these two RCC cell lines following TPM1 transfection. Taken together, TPM1 exhibits characteristics of a tumor-suppressor gene while being overexpressed in RCC cell lines.
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Affiliation(s)
- Jin Wang
- Department of Urology, The First Bethune Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Jingjing Guan
- Department of Urology, The First Bethune Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Zhihua Lu
- Department of Urology, The First Bethune Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Jingji Jin
- Epigenetics Laboratory, School of Life Science, Jilin University, Changchun, Jilin 130012, P.R. China
| | - Yong Cai
- Epigenetics Laboratory, School of Life Science, Jilin University, Changchun, Jilin 130012, P.R. China
| | - Chunxi Wang
- Department of Urology, The First Bethune Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Fei Wang
- Epigenetics Laboratory, School of Life Science, Jilin University, Changchun, Jilin 130012, P.R. China
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16
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Yang W, Wang X, Zheng W, Li K, Liu H, Sun Y. Genetic and epigenetic alterations are involved in the regulation of TPM1 in cholangiocarcinoma. Int J Oncol 2012; 42:690-8. [PMID: 23254774 DOI: 10.3892/ijo.2012.1741] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2012] [Accepted: 11/22/2012] [Indexed: 11/06/2022] Open
Abstract
Cholangiocarcinoma is a malignant tumor originating from biliary epithelial cells. The tumor suppressor gene tropomyosin 1 (TPM1) is downregulated in several human cancer types; however, its expression status in cholangiocarcinoma is still unknown. We elucidated TPM1 expression and its regulation mechanism in cholangiocarcinoma. Real-time (RT)-PCR, western blot analysis and immunohistochemistry were performed to examine TPM1 expression levels in cholangiocarcinoma cell lines and tumor tissues. Cell lines were treated with lentiviral vector containing the miR-21 knockdown and inhibitors of genetic and epigenetic mechanisms (manumycin A, LY294002, U0126, DAC and TSA), and the TPM1 expression change was observed by RT-PCR and western blot analyses. Cell proliferation, apoptosis and migration were evaluated by water-soluble tetrazolium salt (WST-1) assay, flow cytometry and wound healing experiments, respectively. TPM1 was downregulated in the intrahepatic cholangiocarcinoma cells (HuCCT1) and upregulated in the extrahepatic cholangiocarcinoma cells (QBC939) compared with normal intrahepatic biliary epithelial cells (HIBEC). TPM1 stained negative in the intrahepatic cholangiocarcinoma tissues, as revealed by immunohistochemistry, although there was no significant difference in staining of the intrahepatic cholangiocarcinoma tissues and adjacent non-cancer tissues. RAS and two important downstream signaling pathways (RAS/PI3K/AKT and RAS/MEK/ERK) were involved in TPM1 regulation and inhibition of the epigenetic mechanisms such as DNA methylation, histone deacetylation and miR-21 upregulation upregulated TPM1 expression. Inhibitors of genetic and epigenetic mechanisms (manumycin A, LY294002, U0126, DAC and TSA) inhibited cell proliferation and migration and induced apoptosis. These data indicated that TPM1 is downregulated in HuCCT1 cells and that the Ras signaling pathway as well as DNA methylation, histone deacetylation and miR-21 upregulation play important roles in the suppression of TPM1 expression in HuCCT1 cells. Thus, compounds that inhibit genetic and epigenetic mechanisms may be promising agents in treating cholangiocarcinoma.
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Affiliation(s)
- Wei Yang
- Department of Minimally Invasive Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, P.R. China
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17
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Alpha-Dystrobrevin and its associated proteins in human promyelocytic leukemia cells induced to apoptosis. J Proteomics 2012; 75:3291-303. [PMID: 22507200 DOI: 10.1016/j.jprot.2012.03.041] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Revised: 03/19/2012] [Accepted: 03/25/2012] [Indexed: 12/13/2022]
Abstract
Dystrobrevin is a dystrophin-related component of the dystrophin-associated protein complex (DAPC). Using alpha-dystrobrevin as indicator, we aimed to elucidate the interaction network of the DAPC with other proteins during apoptosis of promyelocytic HL-60 cells. The precise role(s) of DBs are not known, but we and others have shown that they play a role in intracellular signal transduction and cellular organization. Apoptosis was induced with etoposide in the absence or presence of Z-VAD to block caspase activity, and we then followed the cellular distribution of α-DB and its association with other proteins, using confocal imaging and cell fractions analyses after immune-precipitation with anti-α-DB and mass spectrometry. Confocal imaging revealed distinct spatial relocalizations of α-DB between the cell membrane, cytosol and nucleus after induction of apoptosis. The expression levels of the identified proteins were evaluated with computer-assisted image analysis of the gels. We thus identified associations with structural and transport proteins (tropomyosin, myosin), membrane (ADAM21, syntrophin), ER-Golgi (TGN51, eIF38) and nuclear (Lamins, ribonucleoprotein C1/C2) proteins. These results suggest that apoptosis-induction in HL-60 cells involves not only classical markers of apoptosis but also a network α-DB-associated proteins at the cell membrane, the cytoplasm and nucleus, affecting key cellular transport processes and cellular structure.
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18
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Choi C, Kim D, Kim S, Jeong S, Song E, Helfman DM. From skeletal muscle to cancer: insights learned elucidating the function of tropomyosin. J Struct Biol 2011; 177:63-9. [PMID: 22119848 DOI: 10.1016/j.jsb.2011.11.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Revised: 11/08/2011] [Accepted: 11/09/2011] [Indexed: 12/17/2022]
Abstract
The tropomyosins (Tms) are a family of actin filament binding proteins that possess a simple dimeric α-helical coiled-coil structure along their entire length. Our knowledge of Tm structure and function has greatly expanded since they were first discovered in skeletal muscle almost 65 years ago. In multicellular organisms they exhibit extensive cell type specific isoform diversity. In this essay we discuss the genetic mechanisms by which this diversity is generated and its significance to actin-based cellular functions.
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Affiliation(s)
- Cheolwon Choi
- Department of Biological Sciences, Korean Advanced Institute of Science and Technology, Daejeon, Republic of Korea
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19
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Zare M, Jazii FR, Soheili ZS, Moghanibashi MM. Downregulation of tropomyosin-1 in squamous cell carcinoma of esophagus, the role of Ras signaling and methylation. Mol Carcinog 2011; 51:796-806. [DOI: 10.1002/mc.20847] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Revised: 07/08/2011] [Accepted: 07/27/2011] [Indexed: 12/16/2022]
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20
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Lees JG, Bach CTT, O'Neill GM. Interior decoration: tropomyosin in actin dynamics and cell migration. Cell Adh Migr 2011; 5:181-6. [PMID: 21173575 DOI: 10.4161/cam.5.2.14438] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Cell migration and invasion requires the precise temporal and spatial orchestration of a variety of biological processes. Filaments of polymerized actin are critical players in these diverse processes, including the regulation of cell anchorage points (both cell-cell and cell-extracellular matrix), the uptake and delivery of molecules via endocytic pathways and the generation of force for both membrane protrusion and retraction. How the actin filaments are specialized for each of these discrete functions is yet to be comprehensively elucidated. The cytoskeletal tropomyosins are a family of actin associating proteins that form head-to-tail polymers which lay in the major groove of polymerized actin filaments. In the present review we summarize the emerging isoform-specific functions of tropomyosins in cell migration and invasion and discuss their potential roles in the specialization of actin filaments for the diverse cellular processes that together regulate cell migration and invasion.
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Affiliation(s)
- Justin G Lees
- Children's Cancer Research Unit, Kids Research Institute, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
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21
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Ku BM, Ryu HW, Lee YK, Ryu J, Jeong JY, Choi J, Cho HJ, Park KH, Kang SS. 4′-Acetoamido-4-hydroxychalcone, a chalcone derivative, inhibits glioma growth and invasion through regulation of the tropomyosin 1 gene. Biochem Biophys Res Commun 2010; 402:525-30. [DOI: 10.1016/j.bbrc.2010.10.068] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Accepted: 10/17/2010] [Indexed: 12/21/2022]
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22
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Wang CLA, Coluccio LM. New insights into the regulation of the actin cytoskeleton by tropomyosin. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2010; 281:91-128. [PMID: 20460184 DOI: 10.1016/s1937-6448(10)81003-2] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The actin cytoskeleton is regulated by a variety of actin-binding proteins including those constituting the tropomyosin family. Tropomyosins are coiled-coil dimers that bind along the length of actin filaments. In muscles, tropomyosin regulates the interaction of actin-containing thin filaments with myosin-containing thick filaments to allow contraction. In nonmuscle cells where multiple tropomyosin isoforms are expressed, tropomyosins participate in a number of cellular events involving the cytoskeleton. This chapter reviews the current state of the literature regarding tropomyosin structure and function and discusses the evidence that tropomyosins play a role in regulating actin assembly.
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23
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Helfman DM, Flynn P, Khan P, Saeed A. Tropomyosin as a regulator of cancer cell transformation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 644:124-31. [PMID: 19209818 DOI: 10.1007/978-0-387-85766-4_10] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Tropomyosins (Tms) are among the most studied structural proteins of the actin cytoskeleton that are implicated in neoplastic-specific alterations in actin filament organization. Decreased expression of specific nonmuscle Tm isoforms is commonly associated with the transformed phenotype. These changes in Tm expression appear to contribute to the rearrangement of microfilament bundles and morphological alterations, increased cell motility and oncogenic signaling properties of transformed cells. Below we review aspects of Tm biology as it specifically relates to transformation and cancer including its expression in culture models of transformed cells and human tumors, mechanisms that regulate Tm expression and the role of Tm in oncogenic signaling.
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Affiliation(s)
- David M Helfman
- Department of Cell Biology and Anatomy, Sylvester Comprehensive Cancer Center, Leonard M. Miller School of Medicine, Papanicolaou Building, Room 317, 1550 NW 10th Avenue (M-877), Miami, Florida 33136, USA.
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24
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Gunning P, O'Neill G, Hardeman E. Tropomyosin-based regulation of the actin cytoskeleton in time and space. Physiol Rev 2008; 88:1-35. [PMID: 18195081 DOI: 10.1152/physrev.00001.2007] [Citation(s) in RCA: 352] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Tropomyosins are rodlike coiled coil dimers that form continuous polymers along the major groove of most actin filaments. In striated muscle, tropomyosin regulates the actin-myosin interaction and, hence, contraction of muscle. Tropomyosin also contributes to most, if not all, functions of the actin cytoskeleton, and its role is essential for the viability of a wide range of organisms. The ability of tropomyosin to contribute to the many functions of the actin cytoskeleton is related to the temporal and spatial regulation of expression of tropomyosin isoforms. Qualitative and quantitative changes in tropomyosin isoform expression accompany morphogenesis in a range of cell types. The isoforms are segregated to different intracellular pools of actin filaments and confer different properties to these filaments. Mutations in tropomyosins are directly involved in cardiac and skeletal muscle diseases. Alterations in tropomyosin expression directly contribute to the growth and spread of cancer. The functional specificity of tropomyosins is related to the collaborative interactions of the isoforms with different actin binding proteins such as cofilin, gelsolin, Arp 2/3, myosin, caldesmon, and tropomodulin. It is proposed that local changes in signaling activity may be sufficient to drive the assembly of isoform-specific complexes at different intracellular sites.
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Affiliation(s)
- Peter Gunning
- Oncology Research Unit, The Children's Hospital at Westmead, and Muscle Development Unit, Children's Medical Research Institute, Westmead; New South Wales, Australia.
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25
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Tropomyosins as interpreters of the signalling environment to regulate the local cytoskeleton. Semin Cancer Biol 2007; 18:35-44. [PMID: 17942320 DOI: 10.1016/j.semcancer.2007.08.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2007] [Accepted: 08/28/2007] [Indexed: 01/11/2023]
Abstract
A key regulator of cell morphology is the actin cytoskeleton and it has long been appreciated that the cytoskeleton is characteristically altered in cancer. Actin is organized into polymeric structures with distinct dynamics which in turn participate in a wide variety of cell processes including adhesion, migration, cell division and apoptosis. Despite displaying an altered actin cytoskeleton, transformed cells retain--and in many cases increase--their ability to adhere, move, divide and respond to apoptotic stimuli. Thus cancer cells maintain responsive actin cytoskeletons. Actin dynamics are regulated by numerous actin-binding proteins and chief among these are the tropomyosins which are core components of the microfilament. Recent advances in genomic and proteomic profiling confirm that Tm expression profiles are profoundly changed in transformed cells. It is therefore timely to review the role of Tms in the regulation of actin dynamics that pertain to crucial phenotypic changes in cancer. In this review we discuss how actin filaments containing different Tm isoforms respond to the activation of cell signalling pathways and consider the implications of this for cancer progression and therapy.
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26
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Gunning PW, Schevzov G, Kee AJ, Hardeman EC. Tropomyosin isoforms: divining rods for actin cytoskeleton function. Trends Cell Biol 2006; 15:333-41. [PMID: 15953552 DOI: 10.1016/j.tcb.2005.04.007] [Citation(s) in RCA: 212] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2004] [Revised: 04/12/2005] [Accepted: 04/26/2005] [Indexed: 01/14/2023]
Abstract
Actin filament functional diversity is paralleled by variation in the composition of isoforms of tropomyosin in these filaments. Although the role of tropomyosin is well understood in skeletal muscle, where it regulates the actin-myosin interaction, its role in the cytoskeleton has been obscure. The intracellular sorting of tropomyosin isoforms indicated a role in spatial specialization of actin filament function. Genetic manipulation and protein chemistry studies have confirmed that these isoforms are functionally distinct. Tropomyosins differ in their recruitment of myosin motors and their interaction with actin filament regulators such as ADF-cofilin. Tropomyosin isoforms have therefore provided a powerful mechanism to diversify actin filament function in different intracellular compartments.
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Affiliation(s)
- Peter W Gunning
- Oncology Research Unit, The Children's Hospital at Westmead, Locked Bag 4001, Westmead NSW 2145, Australia.
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27
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Escobar MA, Hoelz DJ, Sandoval JA, Hickey RJ, Grosfeld JL, Malkas LH. Profiling of nuclear extract proteins from human neuroblastoma cell lines: the search for fingerprints. J Pediatr Surg 2005; 40:349-58. [PMID: 15750928 DOI: 10.1016/j.jpedsurg.2004.10.032] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Neuroblastoma (NB) commonly presents with advanced disease at diagnosis and is associated with poor survival. If identified early, however, survival is improved suggesting a benefit of early detection. The authors have used proteomics technology in an attempt to identify novel markers that permit early detection of NB and characterize its molecular makeup. METHODS Three different human NB cell lines SK-N-AS, SK-N-DZ, and SK-N-FI were subjected to series of biochemical fractionation steps to extract nuclear proteins. These proteins were analyzed for differential expression by 2-dimensional polyacrylamide gel electrophoresis. Polypeptides of interest were subsequently identified by liquid chromatography-linked tandem mass spectrometry. RESULTS Multiple proteins were identified in these human NB cell lines including SET (a ubiquitous nuclear protein), stathmin (a cytosolic signal transduction protein), and grp94 (a heat shock protein). SET is a putative oncogene associated with the chromosomal translocation (6;9) leading to acute undifferentiated leukemia. Stathmin is an oncogene found in greater abundance in leukemic cells compared to nonleukemic cells. A total of 94-kDa glucose-regulated protein has been shown to be protective in human breast cancer cells in vitro and related with the occurrence, differentiation, and progression of human lung cancer. The first protein has not been previously associated with NB. CONCLUSIONS The identification of these 3 previously unrecognized cancer-related potential biomarkers in human NB cell lines may prove useful in developing diagnostic tests. The proteomic methodology of 2-dimensional polyacrylamide gel electrophoresis/mass spectrometry also provides an improved opportunity to understand the natural history of NB and develop novel chemotherapeutic agents for this prevalent childhood malignancy with a dismal outcome.
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Affiliation(s)
- Mauricio A Escobar
- Section of Pediatric Surgery, Department of Surgery, Riley Children's Hospital, Indianapolis, IN 46202, USA
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28
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Bharadwaj S, Hitchcock-DeGregori S, Thorburn A, Prasad GL. N Terminus Is Essential for Tropomyosin Functions. J Biol Chem 2004; 279:14039-48. [PMID: 14722123 DOI: 10.1074/jbc.m310934200] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Down-regulation of several key actin-binding proteins, such as alpha-actinin, vinculin, gelsolin, and tropomyosins (TMs), is considered to contribute to the disorganized cytoskeleton present in many neoplastic cells. TMs stabilize actin filaments against the gel severing actions of proteins such as cofilin. Among multiple TMs expressed in non-muscle cells, tropomyosin-1 (TM1) isoform induces stress fibers and functions as a suppressor of malignant transformation. However, the molecular mechanisms of TM1-mediated cytoskeletal effects and tumor suppression remain poorly understood. We have hypothesized that the ability of TM1 to stabilize microfilaments is crucial for tumor suppression. In this study, by employing a variant TM1, which contains an N-terminal hemagglutinin epitope tag, we demonstrate that the N terminus is a key determinant of tropomyosin-1 function. Unlike the wild type TM1, the modified protein fails to restore stress fibers and inhibit anchorage-independent growth in transformed cells. Furthermore, the N-terminal modification of TM1 disorganizes the cytoskeleton and delays cytokinesis in normal cells, abolishes binding to F-actin, and disrupts the dimeric associations in vivo. The functionally defective TM1 allows the association of cofilin to stress fibers and disorganizes the microfilaments, whereas wild type TM1 appears to restrict the binding of cofilin to stress fibers. TM1-induced cytoskeletal reorganization appears to be mediated through preventing cofilin interaction with microfilaments. Our studies provide in vivo functional evidence that the N terminus is a critical determinant of TM1 functions, which in turn determines the organization of stress fibers.
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Affiliation(s)
- Shantaram Bharadwaj
- Departments of General Surgery and Cancer Biology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA
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