1
|
Zhao B, Yin J, Ding L, Luo J, Luo J, Mu J, Pan S, Du J, Zhong Y, Zhang L, Liu L. SPAG6 regulates cell proliferation and apoptosis via TGF-β/Smad signal pathway in adult B-cell acute lymphoblastic leukemia. Int J Hematol 2024; 119:119-129. [PMID: 38147275 DOI: 10.1007/s12185-023-03684-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 11/09/2023] [Accepted: 11/17/2023] [Indexed: 12/27/2023]
Abstract
Adult B-cell acute lymphoblastic leukemia (B-ALL) prognosis remains unsatisfactory, and searching for new therapeutic targets is crucial for improving patient prognosis. Sperm-associated antigen 6 (SPAG6), a member of the cancer-testis antigen family, plays an important role in tumors, especially hematologic tumors; however, it is unknown whether SPAG6 plays a role in adult B-ALL. In this study, we demonstrated for the first time that SPAG6 expression was up-regulated in the bone marrow of adult B-ALL patients compared to healthy donors, and expression was significantly reduced in patients who achieved complete remission (CR) after treatment. In addition, patients with high SPAG6 expression were older (≥ 35 years; P = 0.015), had elevated white blood cell counts (WBC > 30 × 109/L; P = 0.021), and a low rate of CR (P = 0.036). We explored the SPAG6 effect on cell function by lentiviral transfection of adult B-ALL cell lines BALL-1 and NALM-6, and discovered that knocking down SPAG6 significantly inhibited cell proliferation and promoted apoptosis. We identified that SPAG6 knockdown might regulate cell proliferation and apoptosis via the transforming growth factor-β (TGF-β)/Smad signaling pathway.
Collapse
Affiliation(s)
- Beibei Zhao
- Department of Hematology, Chongqing Medical University, Medical College Road, Yuzhong District, Chongqing, China
- Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400042, China
| | - Jiaxiu Yin
- Department of Hematology, Chongqing Medical University, Medical College Road, Yuzhong District, Chongqing, China
- Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400042, China
| | - Li Ding
- Department of Hematology, Chongqing Medical University, Medical College Road, Yuzhong District, Chongqing, China
- Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400042, China
- Department of Hematology, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, People's Republic of China
| | - Jie Luo
- Department of Hematology, Chongqing Medical University, Medical College Road, Yuzhong District, Chongqing, China
- Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400042, China
| | - Jing Luo
- Department of Hematology, Chongqing Medical University, Medical College Road, Yuzhong District, Chongqing, China
- Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400042, China
| | - Jiao Mu
- Department of Hematology, Chongqing Medical University, Medical College Road, Yuzhong District, Chongqing, China
- Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400042, China
| | - Shirui Pan
- Department of Hematology, Chongqing Medical University, Medical College Road, Yuzhong District, Chongqing, China
- Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400042, China
| | - Juan Du
- Department of Hematology, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, People's Republic of China
| | - Yirui Zhong
- Department of Hematology, Chongqing Medical University, Medical College Road, Yuzhong District, Chongqing, China
| | - Linyi Zhang
- Department of Hematology, Chongqing Medical University, Medical College Road, Yuzhong District, Chongqing, China
| | - Lin Liu
- Department of Hematology, Chongqing Medical University, Medical College Road, Yuzhong District, Chongqing, China.
| |
Collapse
|
2
|
Mu J, Yuan P, Luo J, Chen Y, Tian Y, Ding L, Zhao B, Wang X, Wang B, Liu L. Upregulated SPAG6 promotes acute myeloid leukemia progression through MYO1D that regulates the EGFR family expression. Blood Adv 2022; 6:5379-5394. [PMID: 35667090 PMCID: PMC9631693 DOI: 10.1182/bloodadvances.2021006920] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 06/02/2022] [Indexed: 11/20/2022] Open
Abstract
Chromosomal aberrations and gene mutations have been considered to be the major reasons for high recurrence rates and poor survival among acute myeloid leukemia (AML) patients. However, the underlying molecular mechanism of AML gene mutation remains largely unclear. Here, we show that SPAG6 (sperm-associated antigen 6), one of the most markedly increased SPAG genes in AML, significantly contributed to the proliferation and migration of leukemic cells. SPAG6 was highly expressed in AML, and its upregulation was negatively correlated with the prognosis of the disease. In vitro, SPAG6 promoted the proliferation and migration of leukemia cells and promoted cell cycle progression from the G1 phase to the S phase. In vivo, low expression of SPAG6 reduced the proliferation and infiltration of leukemia cells and prolonged the survival of xenograft tumor mice. Furthermore, immunoprecipitation and mass spectrometry analysis showed that SPAG6 interacts with MYO1D (myosin 1D). Specifically, overexpression of SPAG6 promoted the translocation of MYO1D into the cell membrane, thus upgrading the expression level of the EGFR family and thereby promoting the progression of AML. Overall, our study found that SPAG6 combined with MYO1D and translocated MYO1D from the cytosol to the cytomembrane, which induced the PI3K (phosphoinositide 3-kinase)/AKT (protein kinase B) signaling and ERK (extracellular signal-regulated kinase) signaling pathway to regulate the growth and prognosis of AML. SPAG6 may become a new target gene for the treatment of AML.
Collapse
Affiliation(s)
- Jiao Mu
- Department of Hematology, and
- Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Peng Yuan
- Department of Interventional Radiology and Pain Treatment, Tangdu Hospital, Air Force Medical University, Xi’an, China
| | - Jie Luo
- Department of Hematology, and
- Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yafan Chen
- Department of Human Movement Science, Xi’an Physical Education University, Xi’an, China
| | - Yiyuan Tian
- Department of Physiology, Medical College of Yan’an University, Yan’an, China; and
| | - Li Ding
- Department of Hematology, and
- Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Beibei Zhao
- Department of Hematology, and
- Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Xiaocheng Wang
- Center of Clinical Aerospace Medicine, School of Aerospace Medicine, Key Laboratory of Aerospace Medicine of Ministry of Education
- Department of Aviation Medicine, The First Affiliated Hospital, and
| | - Bao Wang
- Tangdu Hospital, Department of Neurosurgery, Air Force Medical University, Xi’an, China
| | - Lin Liu
- Department of Hematology, and
- Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| |
Collapse
|
3
|
Garcia-Prieto CA, Villanueva L, Bueno-Costa A, Davalos V, González-Navarro EA, Juan M, Urbano-Ispizua Á, Delgado J, Ortiz-Maldonado V, del Bufalo F, Locatelli F, Quintarelli C, Sinibaldi M, Soler M, Castro de Moura M, Ferrer G, Urdinguio RG, Fernandez AF, Fraga MF, Bar D, Meir A, Itzhaki O, Besser MJ, Avigdor A, Jacoby E, Esteller M. Epigenetic Profiling and Response to CD19 Chimeric Antigen Receptor T-Cell Therapy in B-Cell Malignancies. J Natl Cancer Inst 2022; 114:436-445. [PMID: 34581788 PMCID: PMC8902331 DOI: 10.1093/jnci/djab194] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 07/11/2021] [Accepted: 09/22/2021] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Chimeric antigen receptor (CAR) T cells directed against CD19 (CART19) are effective in B-cell malignancies, but little is known about the molecular factors predicting clinical outcome of CART19 therapy. The increasingly recognized relevance of epigenetic changes in cancer immunology prompted us to determine the impact of the DNA methylation profiles of CART19 cells on the clinical course. METHODS We recruited 114 patients with B-cell malignancies, comprising 77 patients with acute lymphoblastic leukemia and 37 patients with non-Hodgkin lymphoma who were treated with CART19 cells. Using a comprehensive DNA methylation microarray, we determined the epigenomic changes that occur in the patient T cells upon transduction of the CAR vector. The effects of the identified DNA methylation sites on clinical response, cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome, event-free survival, and overall survival were assessed. All statistical tests were 2-sided. RESULTS We identified 984 genomic sites with differential DNA methylation between CAR-untransduced and CAR-transduced T cells before infusion into the patient. Eighteen of these distinct epigenetic loci were associated with complete response (CR), adjusting by multiple testing. Using the sites linked to CR, an epigenetic signature, referred to hereafter as the EPICART signature, was established in the initial discovery cohort (n = 79), which was associated with CR (Fisher exact test, P < .001) and enhanced event-free survival (hazard ratio [HR] = 0.36; 95% confidence interval [CI] = 0.19 to 0.70; P = .002; log-rank P = .003) and overall survival (HR = 0.45; 95% CI = 0.20 to 0.99; P = .047; log-rank P = .04;). Most important, the EPICART profile maintained its clinical course predictive value in the validation cohort (n = 35), where it was associated with CR (Fisher exact test, P < .001) and enhanced overall survival (HR = 0.31; 95% CI = 0.11 to 0.84; P = .02; log-rank P = .02). CONCLUSIONS We show that the DNA methylation landscape of patient CART19 cells influences the efficacy of the cellular immunotherapy treatment in patients with B-cell malignancy.
Collapse
Affiliation(s)
- Carlos A Garcia-Prieto
- Cancer and Leukemia Epigenetics and Biology Program (PEBCL), Josep Carreras Leukaemia Research Institute (IJC), Badalona, Spain
- Life Sciences Department, Barcelona Supercomputing Center (BSC), Barcelona, Spain
| | - Lorea Villanueva
- Cancer and Leukemia Epigenetics and Biology Program (PEBCL), Josep Carreras Leukaemia Research Institute (IJC), Badalona, Spain
| | - Alberto Bueno-Costa
- Cancer and Leukemia Epigenetics and Biology Program (PEBCL), Josep Carreras Leukaemia Research Institute (IJC), Badalona, Spain
| | - Veronica Davalos
- Cancer and Leukemia Epigenetics and Biology Program (PEBCL), Josep Carreras Leukaemia Research Institute (IJC), Badalona, Spain
| | | | - Manel Juan
- Department of Immunology, Hospital Clinic, Barcelona, Spain
- Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Álvaro Urbano-Ispizua
- Cancer and Leukemia Epigenetics and Biology Program (PEBCL), Josep Carreras Leukaemia Research Institute (IJC), Badalona, Spain
- Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Department of Hematology, University of Barcelona (UB), Barcelona, Spain
| | - Julio Delgado
- Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Cancer (CIBERONC), Madrid, Spain
| | | | - Francesca del Bufalo
- Department of Paediatric Haematology and Oncology, Cell and Gene Therapy, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Franco Locatelli
- Department of Paediatric Haematology and Oncology, Cell and Gene Therapy, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
- Department of Pediatrics, Sapienza University of Rome, Rome, Italy
| | - Concetta Quintarelli
- Department of Paediatric Haematology and Oncology, Cell and Gene Therapy, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
- Department of Clinical Medicine and Surgery, University of Naples Federico II, Naples, Italy
| | - Matilde Sinibaldi
- Department of Paediatric Haematology and Oncology, Cell and Gene Therapy, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Marta Soler
- Cancer and Leukemia Epigenetics and Biology Program (PEBCL), Josep Carreras Leukaemia Research Institute (IJC), Badalona, Spain
| | - Manuel Castro de Moura
- Cancer and Leukemia Epigenetics and Biology Program (PEBCL), Josep Carreras Leukaemia Research Institute (IJC), Badalona, Spain
| | - Gerardo Ferrer
- Cancer and Leukemia Epigenetics and Biology Program (PEBCL), Josep Carreras Leukaemia Research Institute (IJC), Badalona, Spain
| | - Rocio G Urdinguio
- Nanomaterials and Nanotechnology Research Center (CINNCSIC), Health Research Institute of Asturias (ISPA), Institute of Oncology of Asturias (IUOPA), Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Department of Organisms and Systems Biology (BOS), University of Oviedo, Oviedo, Spain
| | - Agustin F Fernandez
- Nanomaterials and Nanotechnology Research Center (CINNCSIC), Health Research Institute of Asturias (ISPA), Institute of Oncology of Asturias (IUOPA), Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Department of Organisms and Systems Biology (BOS), University of Oviedo, Oviedo, Spain
| | - Mario F Fraga
- Nanomaterials and Nanotechnology Research Center (CINNCSIC), Health Research Institute of Asturias (ISPA), Institute of Oncology of Asturias (IUOPA), Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Department of Organisms and Systems Biology (BOS), University of Oviedo, Oviedo, Spain
| | - Diana Bar
- Division of Pediatric Hematology and Oncology, The Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
| | - Amilia Meir
- Division of Pediatric Hematology and Oncology, The Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
| | - Orit Itzhaki
- Ella Lemelbaum Institute for Immuno Oncology, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
| | - Michal J Besser
- Ella Lemelbaum Institute for Immuno Oncology, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Abraham Avigdor
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
- Institute of Hematology, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
| | - Elad Jacoby
- Division of Pediatric Hematology and Oncology, The Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Manel Esteller
- Cancer and Leukemia Epigenetics and Biology Program (PEBCL), Josep Carreras Leukaemia Research Institute (IJC), Badalona, Spain
- Centro de Investigación Biomédica en Red de Cancer (CIBERONC), Madrid, Spain
- Institucio Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
- Physiological Sciences Department, School of Medicine and Health Sciences, University of Barcelona (UB), Spain
| |
Collapse
|
4
|
Luo J, Mu J, Liu L. [Effects of SPAG6 silencing and decitabine treatment on apoptosis and phosphatase and tensin homolog methylation in SKM-1 cells]. ZHONGHUA XUE YE XUE ZA ZHI = ZHONGHUA XUEYEXUE ZAZHI 2021; 42:1005-1010. [PMID: 35045671 PMCID: PMC8770872 DOI: 10.3760/cma.j.issn.0253-2727.2021.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Indexed: 11/06/2022]
Abstract
Objective: To investigate the effects of SPAG6 silencing and decitabine on apoptosis and phosphatase and tensin homolog (PTEN) methylation in SKM-1 cells in vitro and in vivo. Methods: SKM-1 cells were transfected with a lentiviral vector to silence the expression of SPAG6. Cell survival rate was detected by CCK8 after treatment with decitabine, and cell apoptosis was detected by flow cytometry. Protein expression and methylation of PTEN were detected using Western blot and merozoite surface protein (MSP) . An non-obese diabetic/severe combined inmunodeficiency disease (NOD/SCID) mice xenograft tumor model was established, and the apoptosis and PTEN expression of tumor tissue were observed through terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and immunohistochemistry (IHC) , respectively. Results: After lentivirus transfection, SPAG6 in the interference group was silenced successfully. CCK8 results indicated that the cell survival rate of SKM-1 cells treated with decitabine decreased. Flow cytometry showed that the apoptosis rate of cells treated with decitabine [ (17.35±3.37) %] was higher than that of the untreated group (5.09%±2.06%) and the apoptosis rate of the SPAG6 silencing combined with the decitabine treatment group was the highest [ (36.34±4.00) %]. After treatment with decitabine, the expression of DNMT1 decreased, while the expression of PTEN increased, and the promoter methylation degree of PTEN also decreased. Moreover, the increased protein level caused by PTEN demethylation was the most obvious in the SPAG6 in the interference shRNA group treated with decitabine. In NOD/SCID mice, the tumor volume of the decitabine group was significantly smaller than that of the placebo group, and the tumor volume of the SPAG6 silencing combined with the decitabine treatment group was the smallest. Additionally, the apoptosis rate was the highest (the positive ratio was 3.57±0.48) . Conclusion: SPAG6 silencing may enhance the apoptosis level and the effect of PTEN demethylation in SKM-1 cells and enhance the antitumor effect of decitabine in the NOD/SCID xenograft mouse model.
Collapse
Affiliation(s)
- J Luo
- Department of Hematology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China Experimental Research Center, Chongqing Medical University, Chongqing 400016, China
| | - J Mu
- Department of Hematology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China Experimental Research Center, Chongqing Medical University, Chongqing 400016, China
| | - L Liu
- Department of Hematology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| |
Collapse
|
5
|
Li X, Zhang D, Xu L, Liu W, Zhang N, Strauss JF, Zhang Z, Wang H. Sperm-associated antigen 6 (Spag6) mutation leads to vestibular dysfunction in mice. J Pharmacol Sci 2021; 147:325-330. [PMID: 34663514 DOI: 10.1016/j.jphs.2021.08.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 07/13/2021] [Accepted: 08/10/2021] [Indexed: 12/31/2022] Open
Abstract
Spag6 encodes an axoneme central apparatus protein that is required for normal flagellar and cilia motility. Recent findings suggest that Spag6 plays a role in hearing and planar cell polarity (PCP) in the cochlea of the inner ear. However, a role for Spag6 in the vestibule has not yet been explored. In the present study, the function of Spag6 in the vestibule of the inner ear was examined using Spag6-deficient mice. Our results demonstrate a vestibular disorder in the Spag6 mutants, associated with abnormal ultrastructures of vestibular hair cells and Scarpa's ganglion cells, including swollen stereocilia, decreased crista in mitochondria and swollen Scarpa's ganglion cells. Immunostaining data suggests existence of caspase-dependent apoptosis in vestibular sensory epithelium and Scarpa's ganglion cells. Our observations reveal new functions for Spag6 in vestibular function and apoptosis in the mouse vestibule.
Collapse
Affiliation(s)
- Xiaofei Li
- Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250022, PR China
| | - Daogong Zhang
- Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250022, PR China
| | - Lei Xu
- Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250022, PR China
| | - Wenwen Liu
- Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250022, PR China
| | - Na Zhang
- Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250022, PR China
| | - Jerome F Strauss
- Department of Obstetrics and Gynecology, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | - Zhibing Zhang
- Department of Physiology, Wayne State University, Detroit, MI, 48201, USA; Department of Obstetrics and Gynecology, Wayne State University, Detroit, MI, 48201, USA.
| | - Haibo Wang
- Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250022, PR China.
| |
Collapse
|
6
|
Luo J, Mu J, Zhang M, Zhao B, Liu L. SPAG6-silencing enhances decitabine-induced apoptosis and demethylation of PTEN in SKM-1 cells and in a xenograft mouse model. Leuk Lymphoma 2021; 62:2242-2252. [PMID: 33843428 DOI: 10.1080/10428194.2021.1913148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Myelodysplastic syndromes (MDS) are a group of malignant diseases that are characterized by disordered hematopoiesis with a high risk of transforming into leukemia. In the present study, SPAG6-knockdown and decitabine (DAC) treatment resulted in a decreased DNA methyltransferases and methyl-CpG-binding domain protein expression. In addition, DAC and LBH589 were shown to promote apoptosis in SKM-1 cells, and SPAG6-knockdown to enhance the pro-apoptotic effect of DAC. DAC could reduce PTEN methylation and increase PTEN expression in SKM-1 cells. SPAG6-knockdown and LBH589 treatment could increase DAC-mediated demethylation of PTEN promoter. Finally, a mouse model was constructed, and an enhanced efficacy of DAC following SPAG6-knockdown was confirmed in vivo. In conclusion, DAC-mediated apoptosis and PTEN promoter demethylation may be synergistically enhanced by SPAG6-silencing. Therefore, in the present study it was indicated that SPAG6 may be a potential target for demethylation therapy in MDS.
Collapse
Affiliation(s)
- Jie Luo
- Department of Hematology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.,Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Jiao Mu
- Department of Hematology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.,Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Meng Zhang
- Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Beibei Zhao
- Department of Hematology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Lin Liu
- Department of Hematology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| |
Collapse
|
7
|
Zhang R, Zhu H, Yuan Y, Wang Y, Tian Z. SPAG6 promotes cell proliferation and inhibits apoptosis through the PTEN/PI3K/AKT pathway in Burkitt lymphoma. Oncol Rep 2020; 44:2021-2030. [PMID: 33000212 PMCID: PMC7551011 DOI: 10.3892/or.2020.7776] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 08/25/2020] [Indexed: 12/25/2022] Open
Abstract
The main purpose of the present study was to elucidate the role of sperm‑associated antigen 6 (SPAG6) in the occurrence and development of Burkitt lymphoma (BL) and explore the underlying molecular mechanisms. A correlation was observed between the expression of SPAG6 and the prognosis of patients with lymphoma using The Cancer Genome Atlas (TCGA) database analysis. It was demonstrated that the levels of SPAG6 in BL cells were higher compared with that in IM‑9 cells by reverse transcription‑PCR and western blot assays. Moreover, silencing of SPAG6 significantly decreased proliferation and increased apoptosis of Daudi and Raji cells, whereas SPAG6 overexpression exerted the opposite effects on CA46 and NAMALWA cells. When investigating the possible mechanism, it was first observed that the level of phosphatase and tensin homolog (PTEN) protein was significantly increased, while that of phosphorylated (p‑)AKT protein was markedly reduced in the SPAG6‑knockdown group compared with the blank control group in Daudi and Raji cells by western blot analysis. It was further ascertained whether the phosphoinositide 3‑kinase (PI3K)/PTEN/protein kinase B (AKT) pathway mediates the effects of SPAG6 on cell proliferation and apoptosis, and the results demonstrated that silencing of SPAG6 suppressed the viability of Daudi and Raji cells, whereas PTEN knockdown using siRNA or SF1670 (a specific PTEN inhibitor) reversed the inhibitory effect on cell proliferation and the promoting effect on cell apoptosis induced by SPAG6 depletion in vitro as well as in vivo. These data revealed that SPAG6 may promote the proliferation and inhibit the apoptosis of BL cells via the PTEN/PI3K/AKT pathway. The results of the present study suggest that SPAG6 may play a key role in the progression of BL and may be of value as a predictive prognostic biomarker in patients with BL.
Collapse
Affiliation(s)
- Rongrong Zhang
- Department of Pediatrics, The Affiliated Huaian No. 1 People's Hospital of Nanjing Medical University, Huaian, Jiangsu 223300, P.R. China
| | - Haiyan Zhu
- Department of Pediatrics, The Affiliated Huaian No. 1 People's Hospital of Nanjing Medical University, Huaian, Jiangsu 223300, P.R. China
| | - Yufang Yuan
- Department of Pediatrics, The Affiliated Huaian No. 1 People's Hospital of Nanjing Medical University, Huaian, Jiangsu 223300, P.R. China
| | - Yun Wang
- Department of Pediatrics, The Affiliated Huaian No. 1 People's Hospital of Nanjing Medical University, Huaian, Jiangsu 223300, P.R. China
| | - Zhaofang Tian
- Department of Pediatrics, The Affiliated Huaian No. 1 People's Hospital of Nanjing Medical University, Huaian, Jiangsu 223300, P.R. China
| |
Collapse
|
8
|
Zhang M, Luo J, Luo X, Liu L. SPAG6 silencing induces autophagic cell death in SKM-1 cells via the AMPK/mTOR/ULK1 signaling pathway. Oncol Lett 2020; 20:551-560. [PMID: 32537026 PMCID: PMC7291649 DOI: 10.3892/ol.2020.11607] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 03/06/2020] [Indexed: 02/06/2023] Open
Abstract
As a member of the cancer-testis antigen family, sperm-associated antigen 6 (SPAG6) has been reported to be associated with the pathogenesis of myelodysplastic syndromes (MDS). Previous studies have demonstrated that SPAG6 is upregulated in bone marrow from patients with MDS and MDS-transformed acute myeloid leukemia and that knockdown of SPAG6 expression levels suppressed proliferation and promote apoptosis and differentiation in SKM-1 cells. However, the association between SPAG6 and autophagy in SKM-1 cells remains unclear. Hence, the aim of the present study was to investigate this association and its underlying mechanism. The present study used a short hairpin RNA (shRNA) lentivirus to silence SPAG6 expression levels in SKM-1 cells and demonstrated that SPAG6 knockdown increased autophagy and apoptosis. Furthermore, pharmacologically inhibiting autophagy with chloroquine and 3-methyladenine decreased SPAG6 knockdown-mediated apoptosis, indicating that SPAG6 knockdown-mediated autophagy promoted apoptosis in SKM-1 cells. Additionally, compared with the expression levels in negative control-shRNA lentivirus-transfected SKM-1 cells, the protein expression levels of phosphorylated AMP-activated protein kinase (p-AMPK) and phosphorylated unc-51-like autophagy activating kinase 1 (p-ULK1) were upregulated, while phosphorylated mammalian target of rapamycin (p-mTOR) protein expression was downregulated in SPAG6-shRNA lentivirus-transfected cells. Moreover, inhibiting AMPK expression levels with Compound C, a specific inhibitor of AMPK, attenuated SPAG6 knockdown-induced autophagy and apoptosis, suggesting that AMPK-mediated autophagy enhanced the pro-apoptotic effect of SPAG6 knockdown in SKM-1 cells. Taken together, the results of the present study demonstrated that SPAG6 silencing triggered autophagy via regulation of the AMPK/mTOR/ULK1 signaling pathway, which further contributed to the apoptosis of SKM-1 cells induced by SPAG6 knockdown. Thus, the current results indicate that SPAG6 may be a potential therapeutic target against MDS, and that autophagy may represent a potential mechanism for the treatment of MDS.
Collapse
Affiliation(s)
- Meng Zhang
- Department of Hematology, The First Affiliated Hospital of Chongqing Medical University, Yuzhong, Chongqing 400016, P.R. China.,Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Yuzhong, Chongqing 400016, P.R. China
| | - Jie Luo
- Department of Hematology, The First Affiliated Hospital of Chongqing Medical University, Yuzhong, Chongqing 400016, P.R. China.,Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Yuzhong, Chongqing 400016, P.R. China
| | - Xiaohua Luo
- Department of Hematology, The First Affiliated Hospital of Chongqing Medical University, Yuzhong, Chongqing 400016, P.R. China
| | - Lin Liu
- Department of Hematology, The First Affiliated Hospital of Chongqing Medical University, Yuzhong, Chongqing 400016, P.R. China
| |
Collapse
|
9
|
The Emerging Role of Sperm-Associated Antigen 6 Gene in the Microtubule Function of Cells and Cancer. MOLECULAR THERAPY-ONCOLYTICS 2019; 15:101-107. [PMID: 31660426 PMCID: PMC6807308 DOI: 10.1016/j.omto.2019.08.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Accumulated evidence shows that sperm-associated antigen 6 (SPAG6) gene has multiple biological functions. It maintains the normal function of a variety of cells including ciliary/flagellar biogenesis and polarization, neurogenesis, and neuronal migration. Moreover, SPAG6 is found to be critically involved in auditory transduction and the fibroblast life cycle. Furthermore, SPAG6 plays an essential role in immuno-regulation. Notably, SPAG6 has been demonstrated to participate in the occurrence and progression of a variety of human cancers. New evidence shows that SPAG6 gene regulates tumor cell proliferation, apoptosis, invasion, and metastasis. Therefore, in this review, we describe the physiological function and mechanism of SPAG6 in human normal cells and cancer cells. We also highlight that SPAG6 gene may be an effective biomarker for the diagnosis of human cancer. Taken together, targeting SPAG6 could be a novel strategy for the treatment of human diseases including cancer.
Collapse
|
10
|
Liang HW, Luo B, Du LH, He RQ, Chen G, Peng ZG, Ma J. Expression significance and potential mechanism of hypoxia-inducible factor 1 alpha in patients with myelodysplastic syndromes. Cancer Med 2019; 8:6021-6035. [PMID: 31411003 PMCID: PMC6792495 DOI: 10.1002/cam4.2447] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 06/21/2019] [Accepted: 07/11/2019] [Indexed: 12/22/2022] Open
Abstract
Objective To investigate the expression level and potential mechanism of hypoxia‐inducible factor 1 alpha (HIF‐1α) in patients with myelodysplastic syndromes (MDS). Methods Immunohistochemistry (IHC) techniques were used to examine the protein expression of HIF‐1α in paraffin‐embedded myeloid tissues from 82 patients with MDS and 33 controls (patients with lymphoma that is not invading myeloid tissues). In addition, the associations between the protein expression of HIF‐1α and clinical parameters were examined. To further investigate the significance of HIF‐1α expression in MDS patients, the researchers not only extracted the data about HIF‐1α expression from MDS‐related microarrays but also analyzed the correlation between the level of HIF‐1α expression and MDS. The microRNA (miRNA) targeting HIF‐1α was predicted and verified with a dual luciferase experiment. Results Immunohistochemistry revealed that the positive expression rate of HIF‐1α in the bone marrow of patients with MDS was 90.24%. This rate was remarkably higher than that of the controls (72.73%) and was statistically significant (P < .05), which indicated that HIF‐1α was upregulated in the myeloid tissues of MDS patients. For the GSE2779, GSE18366, GSE41130, and GSE61853 microarrays, the average expression of HIF‐1α in MDS patients was higher than in the controls. Particularly for the GSE18366 microarray, HIF‐1α expression was considerably higher in MDS patients than in the controls (P < .05). It was predicted that miR‐93‐5p had a site for binding with HIF‐1α, and a dual luciferase experiment confirmed that miR‐93‐5p could bind with HIF‐1α. Conclusion The upregulated expression of HIF‐1α was examined in the myeloid tissues of MDS patients. The presence of HIF‐1α (+) suggested an unsatisfactory prognosis for patients, which could assist in the diagnosis of MDS. In addition, miR‐93‐5p could bind to HIF‐1α by targeting, showing its potential to be the target of HIF‐1α in MDS.
Collapse
Affiliation(s)
- Hai-Wei Liang
- Department of Pathology, The First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
| | - Bin Luo
- Department of Medical Oncology, The First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
| | - Li-Hua Du
- Department of Medical Oncology, The First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
| | - Rong-Quan He
- Department of Medical Oncology, The First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
| | - Gang Chen
- Department of Pathology, The First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
| | - Zhi-Gang Peng
- Department of Medical Oncology, The First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
| | - Jie Ma
- Department of Medical Oncology, The First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
| |
Collapse
|
11
|
Jiang M, Chen Y, Deng L, Luo X, Wang L, Liu L. Upregulation of SPAG6 in Myelodysplastic Syndrome: Knockdown Inhibits Cell Proliferation via AKT/FOXO Signaling Pathway. DNA Cell Biol 2019; 38:476-484. [PMID: 30835546 DOI: 10.1089/dna.2018.4521] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Recently, sperm-associated antigen 6 (SPAG6), a member of the cancer-testis antigen family, has been shown to be involved in tumorigenesis. An increasing number of studies have shown that SPAG6 expression is associated with the pathogenesis of myelodysplastic syndrome (MDS). However, the mechanism has not been clearly elucidated. Our previous results indicated that SPAG6 affected cell apoptosis in MDS. In this study, we used reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to demonstrate that the mRNA expression of SPAG6 in bone marrow cells of patients with MDS or MDS-derived acute myeloid leukemia (MDS-AML) was higher than that of cancer-free patients. Kaplan-Meier survival curve analysis of published AML found that patients with high expression of SPAG6 had poor survival. The results of the cell counting kit-8, FACS, RT-qPCR, and Western blotting assays indicated that SPAG6 knockdown in the SKM-1 cell line inhibited cell proliferation, and affected cell cycle and differentiation. Furthermore, we found that SPAG6 knockdown affected the proliferation of SKM-1 cells by mediating the G1-to-S transition of the cell cycle. Moreover, we demonstrated that the antiproliferative effect of SPAG6 knockdown was associated with the upregulation of the cyclin-dependent kinase inhibitor p27Kip1, and regulation of the AKT/FOXO pathway. These findings indicated that SPAG6 might be a potential therapeutic target.
Collapse
Affiliation(s)
- Mei Jiang
- Department of Hematology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, P.R. China
| | - Ya Chen
- Department of Hematology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, P.R. China
| | - Linli Deng
- Department of Hematology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, P.R. China
| | - Xiaohua Luo
- Department of Hematology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, P.R. China
| | - Li Wang
- Department of Hematology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, P.R. China
| | - Lin Liu
- Department of Hematology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, P.R. China
| |
Collapse
|
12
|
Coan M, Rampioni Vinciguerra GL, Cesaratto L, Gardenal E, Bianchet R, Dassi E, Vecchione A, Baldassarre G, Spizzo R, Nicoloso MS. Exploring the Role of Fallopian Ciliated Cells in the Pathogenesis of High-Grade Serous Ovarian Cancer. Int J Mol Sci 2018; 19:ijms19092512. [PMID: 30149579 PMCID: PMC6163198 DOI: 10.3390/ijms19092512] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 08/20/2018] [Accepted: 08/20/2018] [Indexed: 12/22/2022] Open
Abstract
High-grade serous epithelial ovarian cancer (HGSOC) is the fifth leading cause of cancer death in women and the first among gynecological malignancies. Despite an initial response to standard chemotherapy, most HGSOC patients relapse. To improve treatment options, we must continue investigating tumor biology. Tumor characteristics (e.g., risk factors and epidemiology) are valuable clues to accomplish this task. The two most frequent risk factors for HGSOC are the lifetime number of ovulations, which is associated with increased oxidative stress in the pelvic area caused by ovulation fluid, and a positive family history due to genetic factors. In the attempt to identify novel genetic factors (i.e., genes) associated with HGSOC, we observed that several genes in linkage with HGSOC are expressed in the ciliated cells of the fallopian tube. This finding made us hypothesize that ciliated cells, despite not being the cell of origin for HGSOC, may take part in HGSOC tumor initiation. Specifically, malfunction of the ciliary beat impairs the laminar fluid flow above the fallopian tube epithelia, thus likely reducing the clearance of oxidative stress caused by follicular fluid. Herein, we review the up-to-date findings dealing with HGSOC predisposition with the hypothesis that fallopian ciliated cells take part in HGSOC onset. Finally, we review the up-to-date literature concerning genes that are located in genomic loci associated with epithelial ovarian cancer (EOC) predisposition that are expressed by the fallopian ciliated cells.
Collapse
Affiliation(s)
- Michela Coan
- Division of Molecular Oncology, Department of Translational Research, IRCCS CRO Aviano-National Cancer Institute, Via Franco Gallini, 2 33081 Aviano PN, Italy.
| | - Gian Luca Rampioni Vinciguerra
- Division of Molecular Oncology, Department of Translational Research, IRCCS CRO Aviano-National Cancer Institute, Via Franco Gallini, 2 33081 Aviano PN, Italy.
| | - Laura Cesaratto
- Division of Molecular Oncology, Department of Translational Research, IRCCS CRO Aviano-National Cancer Institute, Via Franco Gallini, 2 33081 Aviano PN, Italy.
| | - Emanuela Gardenal
- Azienda Ospedaliera Universitaria Integrata, University of Verona, 37129 Verona, Italy.
| | - Riccardo Bianchet
- Scientific Direction, CRO Aviano Italy, Via Franco Gallini, 2 33081 Aviano, Italy.
| | - Erik Dassi
- Centre for Integrative Biology, University of Trento, 38122 Trento, Italy.
| | - Andrea Vecchione
- Department of clinical and molecular medicine, university of Rome "Sapienza", c/o sant andrea hospital, Via di Grottarossa 1035, 00189 Rome, Italy.
| | - Gustavo Baldassarre
- Division of Molecular Oncology, Department of Translational Research, IRCCS CRO Aviano-National Cancer Institute, Via Franco Gallini, 2 33081 Aviano PN, Italy.
| | - Riccardo Spizzo
- Division of Molecular Oncology, Department of Translational Research, IRCCS CRO Aviano-National Cancer Institute, Via Franco Gallini, 2 33081 Aviano PN, Italy.
| | - Milena Sabrina Nicoloso
- Division of Molecular Oncology, Department of Translational Research, IRCCS CRO Aviano-National Cancer Institute, Via Franco Gallini, 2 33081 Aviano PN, Italy.
| |
Collapse
|
13
|
Yin J, Li X, Zhang Z, Luo X, Wang L, Liu L. SPAG6 silencing induces apoptosis in the myelodysplastic syndrome cell line SKM‑1 via the PTEN/PI3K/AKT signaling pathway in vitro and in vivo. Int J Oncol 2018; 53:297-306. [PMID: 29749435 DOI: 10.3892/ijo.2018.4390] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 02/27/2018] [Indexed: 11/05/2022] Open
Abstract
Apoptosis is a multi-step mechanism of cell self‑destruction for maintaining cellular homeostatic balance. Accumulating evidence indicates that abnormal apoptosis promotes the evolution and progression of myelodysplastic syndromes (MDS). As a novel cancer-testis antigen, sperm‑associated antigen 6 (SPAG6) has been reported to regulate apoptosis through the tumor necrosis factor-related apoptosis-inducing ligand signaling pathway in the MDS cell line SKM‑1. However, the mechanism of the intrinsic cell death pathway for apoptosis induction by SPAG6 silencing is unclear. In the present study, the in vitro effects of SPAG6 silencing were investigated in SKM‑1 cells through extensive biochemical and molecular approaches. Western blotting and reverse transcription-quantitative polymerase chain reaction were used to detect the expression of SPAG6 and activation of PTEN/PI3K/AKT signal pathway. Additionally, SKM‑1 cells transduced with SPAG6 short hairpin RNA (shRNA) lentivirus were treated with the phosphatidylionositol 3-kinase (PI3K) inhibitor LY294002 or pan caspase inhibitor z‑VAD‑fmk and the apoptosis rates were measured by flow cytometry, and the expressions of associated proteins were examined by western blot analysis. A mouse xenograft model was also used to further evaluate the effects of SPAG6 knockdown on inducing tumor apoptosis in vivo. Lentivirus-mediated knockdown of SPAG6 in SKM‑1 cells increased phosphatase and tensin homolog (PTEN) expression and reduced protein kinase B (AKT) phosphorylation, which in turn resulted in cell apoptosis as evidenced by induced myeloid leukaemia cell differentiation protein Mcl‑1 downregulation, cytochrome c release and increased caspase‑9 expression. Consistently, the PI3K inhibitor LY294002 synergistically enhanced apoptosis of SKM‑1 cells when co-administered with SPAG6 shRNA lentivirus. Furthermore, treatment with the pan caspase inhibitor z‑VAD‑fmk failed to prevent PTEN activation upon SPAG6 knockdown, suggesting that SPAG6-regulated PTEN expression was caspase activation-independent. In addition, SPAG6 knockdown was associated with DNMT1 downregulation, implying that SPAG6 may indirectly control PTEN expression via DNA methylation. Furthermore, tumor tissues from nonobese diabetic/severe combined immunodeficient mice inoculated with SPAG6-shRNA lentivirus pre-infected SKM‑1 cells exhibited significantly elevated apoptosis in the extrinsic and intrinsic pathways. These results demonstrate that SPAG6 silencing induces PTEN expression to regulate apoptosis though the PI3K/AKT pathway, indicating that SPAG6 may be a potential therapeutic target for MDS.
Collapse
Affiliation(s)
- Jiaxiu Yin
- Department of Hematology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China
| | - Xinxin Li
- Department of Hematology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China
| | - Zaili Zhang
- Department of Hematology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China
| | - Xiaohua Luo
- Department of Hematology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China
| | - Li Wang
- Department of Hematology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China
| | - Lin Liu
- Department of Hematology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China
| |
Collapse
|
14
|
Li X, Xu L, Sun G, Wu X, Bai X, Li J, Strauss JF, Zhang Z, Wang H. Spag6 Mutant Mice Have Defects in Development and Function of Spiral Ganglion Neurons, Apoptosis, and Higher Sensitivity to Paclitaxel. Sci Rep 2017; 7:8638. [PMID: 28819108 PMCID: PMC5561245 DOI: 10.1038/s41598-017-08739-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 07/17/2017] [Indexed: 12/20/2022] Open
Abstract
Mammalian Sperm Associated Antigen 6 (SPAG6) is the orthologue of Chlamydomonas PF16, a protein localized in the axoneme central apparatus. Recent studies showed that Spag6 has a role in brain neuronal proliferation and differentiation. The mammalian spiral ganglion neurons (SGNs) are specialzed bipolar neurons in the inner ear. However, the role of SPAG6 in SGN has not been elucidated. Therefore, We hypothesized that a Spag6 knockout would affect the development and function of SGNs. We utilized Spag6-deficient mice and SGN explants to define the role of SPAG6. On postnatal day 30 (P30) mutant mice had lower SGN density compared to their wild-type littermates, and more apoptosis was evident in the mutants. Increased Bax expression, a disturbed distribution of cytochrome c, and cleaved caspase-3 positive staining indicated that increased apoptosis involved a mitochondrial pathway. Transmission electron microscopy revealed abnormalities in the ultrastructure of mutant SGNs as early as P7. In vitro, lack of SPAG6 affected the growth of neurites and growth cones. Additionally, SPAG6 deficiency decreased synapse density in SGN explants. Finally, Spag6 mutant SGNs were more sensitive to the microtubule stabilizing agent, paclitaxel. These findings suggest that Spag6 plays a crucial role in SGN development and function.
Collapse
Affiliation(s)
- Xiaofei Li
- Otolaryngology-Head and Neck Surgery, Provincial Hospital Affiliated to Shandong University, Jinan, PR China
- Shandong Provincial Key Laboratory of Otology, Jinan, PR China
| | - Lei Xu
- Otolaryngology-Head and Neck Surgery, Provincial Hospital Affiliated to Shandong University, Jinan, PR China
| | - Gaoying Sun
- Shandong Provincial Key Laboratory of Otology, Jinan, PR China
| | - Xianmin Wu
- Otolaryngology-Head and Neck Surgery, Provincial Hospital Affiliated to Shandong University, Jinan, PR China
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, PR China
| | - Xiaohui Bai
- Shandong Provincial Key Laboratory of Otology, Jinan, PR China
| | - Jianfeng Li
- Shandong Provincial Key Laboratory of Otology, Jinan, PR China
| | - Jerome F Strauss
- Department of Obstetrics and Gynecology, Virginia Commonwealth University, Richmond, VA, 23298, USA
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | - Zhibing Zhang
- Department of Obstetrics and Gynecology, Virginia Commonwealth University, Richmond, VA, 23298, USA.
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA, 23298, USA.
| | - Haibo Wang
- Otolaryngology-Head and Neck Surgery, Provincial Hospital Affiliated to Shandong University, Jinan, PR China.
- Shandong Provincial Key Laboratory of Otology, Jinan, PR China.
| |
Collapse
|