51
|
Huang J, Chen H, Wei Q, Zhang Z, Zhong Z, Xu Y. Downregulation of LKB1 promotes tumor progression and predicts unfavorable prognosis in patients with glioma. Oncol Lett 2017; 13:1688-1694. [PMID: 28454310 PMCID: PMC5403413 DOI: 10.3892/ol.2017.5631] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 10/21/2016] [Indexed: 01/24/2023] Open
Abstract
The liver kinase B1 (LKB1)/5′-adenosine monophosphate-activated protein kinase pathway has been reported to facilitate glioma cell growth by improving growth conditions. To investigate the clinical significance of LKB1 in human gliomas western blot analysis and quantitative polymerase chain reaction experiments were performed. The present study demonstrated that LKB1 expression was markedly decreased at the messenger RNA and protein levels in 30 freshly prepared glioma tissues, compared with non-neoplastic brain tissues (P<0.001). Subsequently, immunohistochemical analysis demonstrated that LKB1 immunostaining in 180 glioma tissues was significantly decreased compared with that in the corresponding non-neoplastic brain tissues (P<0.001). Notably, this downregulation frequently occurred in high-grade gliomas, and statistical analysis revealed that low LKB1 expression was significantly associated with large tumor size (P=0.02), advanced World Health Organization grade (P=0.006) and low Karnofsky performance scale (P=0.01). The prognostic value of LKB1 expression in patients with glioma was additionally evaluated using Kaplan-Meier survival curves and Cox proportional hazards regression models. As a result, the overall survival time of patients with glioma with low LKB1 expression was shorter compared with that of patients with high LKB1 expression (P<0.001), and low LKB1 expression also indicated decreased survival time in patients with high-grade glioma (P<0.001). Collectively, the present data indicated that the downregulation of LKB1 was closely associated with the malignant degree of human gliomas, exhibiting lower expression at a higher grade. Notably, LKB1 may serve as a potential prognostic biomarker for patients with glioma following surgery.
Collapse
Affiliation(s)
- Jiehao Huang
- Department of Neurosurgery, The First Affiliated Hospital of Medical College, Shantou University, Shantou, Guangdong 515041, P.R. China
| | - Hongwu Chen
- Department of Neurosurgery, The First Affiliated Hospital of Medical College, Shantou University, Shantou, Guangdong 515041, P.R. China
| | - Quantang Wei
- Department of Neurosurgery, The First Affiliated Hospital of Medical College, Shantou University, Shantou, Guangdong 515041, P.R. China
| | - Ziheng Zhang
- Department of Neurosurgery, The First Affiliated Hospital of Medical College, Shantou University, Shantou, Guangdong 515041, P.R. China
| | - Zhiwei Zhong
- Department of Neurosurgery, The First Affiliated Hospital of Medical College, Shantou University, Shantou, Guangdong 515041, P.R. China
| | - Yimin Xu
- Department of Neurosurgery, The First Affiliated Hospital of Medical College, Shantou University, Shantou, Guangdong 515041, P.R. China
| |
Collapse
|
52
|
Mei Y, Yang JP, Qian CN. For robust big data analyses: a collection of 150 important pro-metastatic genes. CHINESE JOURNAL OF CANCER 2017; 36:16. [PMID: 28109319 PMCID: PMC5251273 DOI: 10.1186/s40880-016-0178-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 11/03/2016] [Indexed: 02/08/2023]
Abstract
Metastasis is the greatest contributor to cancer-related death. In the era of precision medicine, it is essential to predict and to prevent the spread of cancer cells to significantly improve patient survival. Thanks to the application of a variety of high-throughput technologies, accumulating big data enables researchers and clinicians to identify aggressive tumors as well as patients with a high risk of cancer metastasis. However, there have been few large-scale gene collection studies to enable metastasis-related analyses. In the last several years, emerging efforts have identified pro-metastatic genes in a variety of cancers, providing us the ability to generate a pro-metastatic gene cluster for big data analyses. We carefully selected 285 genes with in vivo evidence of promoting metastasis reported in the literature. These genes have been investigated in different tumor types. We used two datasets downloaded from The Cancer Genome Atlas database, specifically, datasets of clear cell renal cell carcinoma and hepatocellular carcinoma, for validation tests, and excluded any genes for which elevated expression level correlated with longer overall survival in any of the datasets. Ultimately, 150 pro-metastatic genes remained in our analyses. We believe this collection of pro-metastatic genes will be helpful for big data analyses, and eventually will accelerate anti-metastasis research and clinical intervention.
Collapse
Affiliation(s)
- Yan Mei
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China
| | - Jun-Ping Yang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China
| | - Chao-Nan Qian
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China. .,Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China.
| |
Collapse
|
53
|
Abstract
To help define the molecular basis of cellular signalling cascades, and their biological functions, there is considerable value in utilizing a high-quality chemical 'probe' that has a well-defined interaction with a specific cellular protein. Such reagents include inhibitors of protein kinases and small molecule kinases, as well as mimics or antagonists of intracellular signals. The purpose of this review is to consider recent progress and promising future directions for the development of novel molecules that can interrogate and manipulate the cellular actions of inositol pyrophosphates (PP-IPs)--a specialized, 'energetic' group of cell-signalling molecules in which multiple phosphate and diphosphate groups are crammed around a cyclohexane polyol scaffold.
Collapse
|
54
|
Gu C, Wilson MSC, Jessen HJ, Saiardi A, Shears SB. Inositol Pyrophosphate Profiling of Two HCT116 Cell Lines Uncovers Variation in InsP8 Levels. PLoS One 2016; 11:e0165286. [PMID: 27788189 PMCID: PMC5082907 DOI: 10.1371/journal.pone.0165286] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 09/09/2016] [Indexed: 11/18/2022] Open
Abstract
The HCT116 cell line, which has a pseudo-diploid karotype, is a popular model in the fields of cancer cell biology, intestinal immunity, and inflammation. In the current study, we describe two batches of diverged HCT116 cells, which we designate as HCT116NIH and HCT116UCL. Using both gel electrophoresis and HPLC, we show that HCT116UCL cells contain 6-fold higher levels of InsP8 than HCT116NIH cells. This observation is significant because InsP8 is one of a group of molecules collectively known as ‘inositol pyrophosphates’ (PP-InsPs)—highly ‘energetic’ and conserved regulators of cellular and organismal metabolism. Variability in the cellular levels of InsP8 within divergent HCT116 cell lines could have impacted the phenotypic data obtained in previous studies. This difference in InsP8 levels is more remarkable for being specific; levels of other inositol phosphates, and notably InsP6 and 5-InsP7, are very similar in both HCT116NIH and HCT116UCL lines. We also developed a new HPLC procedure to record 1-InsP7 levels directly (for the first time in any mammalian cell line); 1-InsP7 comprised <2% of total InsP7 in HCT116NIH and HCT116UCL lines. The elevated levels of InsP8 in the HCT116UCL lines were not due to an increase in expression of the PP-InsP kinases (IP6Ks and PPIP5Ks), nor to a decrease in the capacity to dephosphorylate InsP8. We discuss how the divergent PP-InsP profiles of the newly-designated HCT116NIH and HCT116UCL lines should be considered an important research opportunity: future studies using these two lines may uncover new features that regulate InsP8 turnover, and may also yield new directions for studying InsP8 function.
Collapse
Affiliation(s)
- Chunfang Gu
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, 101 T.W. Alexander Drive, Research Triangle Park, North Carolina, 27709, United States of America
| | - Miranda S. C. Wilson
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Henning J. Jessen
- Institute of Organic Chemistry, Albert-Ludwigs-University, Freiburg, Albertstr. 21, 79104, Freiburg, Germany
| | - Adolfo Saiardi
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
- * E-mail: (AS); (SS)
| | - Stephen B. Shears
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, 101 T.W. Alexander Drive, Research Triangle Park, North Carolina, 27709, United States of America
- * E-mail: (AS); (SS)
| |
Collapse
|
55
|
Shears SB, Baughman BM, Gu C, Nair VS, Wang H. The significance of the 1-kinase/1-phosphatase activities of the PPIP5K family. Adv Biol Regul 2016; 63:98-106. [PMID: 27776974 DOI: 10.1016/j.jbior.2016.10.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Revised: 10/13/2016] [Accepted: 10/15/2016] [Indexed: 01/29/2023]
Abstract
The inositol pyrophosphates (diphosphoinositol polyphosphates), which include 1-InsP7, 5-InsP7, and InsP8, are highly 'energetic' signaling molecules that play important roles in many cellular processes, particularly with regards to phosphate and bioenergetic homeostasis. Two classes of kinases synthesize the PP-InsPs: IP6Ks and PPIP5Ks. The significance of the IP6Ks - and their 5-InsP7 product - has been widely reported. However, relatively little is known about the biological significance of the PPIP5Ks. The purpose of this review is to provide an update on developments in our understanding of key features of the PPIP5Ks, which we believe strengthens the hypothesis that their catalytic activities serve important cellular functions. Central to this discussion is the recent discovery that the PPIP5K is a rare example of a single protein that catalyzes a kinase/phosphatase futile cycle.
Collapse
Affiliation(s)
- Stephen B Shears
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, 101 T.W. Alexander Drive, Research Triangle Park, NC, 27709, USA.
| | - Brandi M Baughman
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, 101 T.W. Alexander Drive, Research Triangle Park, NC, 27709, USA
| | - Chunfang Gu
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, 101 T.W. Alexander Drive, Research Triangle Park, NC, 27709, USA
| | - Vasudha S Nair
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, 101 T.W. Alexander Drive, Research Triangle Park, NC, 27709, USA
| | - Huanchen Wang
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, 101 T.W. Alexander Drive, Research Triangle Park, NC, 27709, USA
| |
Collapse
|
56
|
Zhu Q, Ghoshal S, Rodrigues A, Gao S, Asterian A, Kamenecka TM, Barrow JC, Chakraborty A. Adipocyte-specific deletion of Ip6k1 reduces diet-induced obesity by enhancing AMPK-mediated thermogenesis. J Clin Invest 2016; 126:4273-4288. [PMID: 27701146 DOI: 10.1172/jci85510] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 08/29/2016] [Indexed: 12/15/2022] Open
Abstract
Enhancing energy expenditure (EE) is an attractive strategy to combat obesity and diabetes. Global deletion of Ip6k1 protects mice from diet-induced obesity (DIO) and insulin resistance, but the tissue-specific mechanism by which IP6K1 regulates body weight is unknown. Here, we have demonstrated that IP6K1 regulates fat accumulation by modulating AMPK-mediated adipocyte energy metabolism. Cold exposure led to downregulation of Ip6k1 in murine inguinal and retroperitoneal white adipose tissue (IWAT and RWAT) depots. Adipocyte-specific deletion of Ip6k1 (AdKO) enhanced thermogenic EE, which protected mice from high-fat diet-induced weight gain at ambient temperature (23°C), but not at thermoneutral temperature (30°C). AdKO-induced increases in thermogenesis also protected mice from cold-induced decreases in body temperature. UCP1, PGC1α, and other markers of browning and thermogenesis were elevated in IWAT and RWAT of AdKO mice. Cold-induced activation of sympathetic signaling was unaltered, whereas AMPK was enhanced, in AdKO IWAT. Moreover, beige adipocytes from AdKO IWAT displayed enhanced browning, which was diminished by AMPK depletion. Furthermore, we determined that IP6 and IP6K1 differentially regulate upstream kinase-mediated AMPK stimulatory phosphorylation in vitro. Finally, treating mildly obese mice with the IP6K inhibitor TNP enhanced thermogenesis and inhibited progression of DIO. Thus, IP6K1 regulates energy metabolism via a mechanism that could potentially be targeted in obesity.
Collapse
|
57
|
Moritoh Y, Oka M, Yasuhara Y, Hozumi H, Iwachidow K, Fuse H, Tozawa R. Inositol Hexakisphosphate Kinase 3 Regulates Metabolism and Lifespan in Mice. Sci Rep 2016; 6:32072. [PMID: 27577108 PMCID: PMC5006000 DOI: 10.1038/srep32072] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 08/02/2016] [Indexed: 12/26/2022] Open
Abstract
Inositol hexakisphosphate kinase 3 (IP6K3) generates inositol pyrophosphates, which regulate diverse cellular functions. However, little is known about its own physiological role. Here, we show the roles of IP6K3 in metabolic regulation. We detected high levels of both mouse and human IP6K3 mRNA in myotubes and muscle tissues. In human myotubes, IP6K3 was upregulated by dexamethasone treatment, which is known to inhibit glucose metabolism. Furthermore, Ip6k3 expression was elevated under diabetic, fasting, and disuse conditions in mouse skeletal muscles. Ip6k3(-/-) mice demonstrated lower blood glucose, reduced circulating insulin, deceased fat mass, lower body weight, increased plasma lactate, enhanced glucose tolerance, lower glucose during an insulin tolerance test, and reduced muscle Pdk4 expression under normal diet conditions. Notably, Ip6k3 deletion extended animal lifespan with concomitant reduced phosphorylation of S6 ribosomal protein in the heart. In contrast, Ip6k3(-/-) mice showed unchanged skeletal muscle mass and no resistance to the effects of high fat diet. The current observations suggest novel roles of IP6K3 in cellular regulation, which impact metabolic control and lifespan.
Collapse
Affiliation(s)
- Yusuke Moritoh
- Cardiovascular and Metabolic Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Masahiro Oka
- Cardiovascular and Metabolic Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Yoshitaka Yasuhara
- Cardiovascular and Metabolic Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Hiroyuki Hozumi
- Cardiovascular and Metabolic Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Kimihiko Iwachidow
- Integrated Technology Research Laboratories, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Hiromitsu Fuse
- Integrated Technology Research Laboratories, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Ryuichi Tozawa
- Cardiovascular and Metabolic Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| |
Collapse
|
58
|
Hager A, Wu M, Wang H, Brown NW, Shears SB, Veiga N, Fiedler D. Cellular Cations Control Conformational Switching of Inositol Pyrophosphate Analogues. Chemistry 2016; 22:12406-14. [PMID: 27460418 PMCID: PMC5076471 DOI: 10.1002/chem.201601754] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Indexed: 12/21/2022]
Abstract
The inositol pyrophosphate messengers (PP-InsPs) are emerging as an important class of cellular regulators. These molecules have been linked to numerous biological processes, including insulin secretion and cancer cell migration, but how they trigger such a wide range of cellular responses has remained unanswered in many cases. Here, we show that the PP-InsPs exhibit complex speciation behaviour and propose that a unique conformational switching mechanism could contribute to their multifunctional effects. We synthesised non-hydrolysable bisphosphonate analogues and crystallised the analogues in complex with mammalian PPIP5K2 kinase. Subsequently, the bisphosphonate analogues were used to investigate the protonation sequence, metal-coordination properties, and conformation in solution. Remarkably, the presence of potassium and magnesium ions enabled the analogues to adopt two different conformations near physiological pH. Understanding how the intrinsic chemical properties of the PP-InsPs can contribute to their complex signalling outputs will be essential to elucidate their regulatory functions.
Collapse
Affiliation(s)
- Anastasia Hager
- Department of Chemistry, Princeton University, Washington Rd., Princeton, New Jersey, 08544, USA
| | - Mingxuan Wu
- Department of Chemistry, Princeton University, Washington Rd., Princeton, New Jersey, 08544, USA
| | - Huanchen Wang
- Inositol Signaling Group, National Institutes of Health, Research Triangle Park, North Carolina, 27709, USA
| | - Nathaniel W Brown
- Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle Strasse 10, 13125, Berlin, Germany
- Department of Chemistry, Princeton University, Washington Rd., Princeton, New Jersey, 08544, USA
| | - Stephen B Shears
- Inositol Signaling Group, National Institutes of Health, Research Triangle Park, North Carolina, 27709, USA
| | - Nicolás Veiga
- Cátedra de Química Inorgánica, Departamento Estrella Campos, Facultad de Química, Universidad de la República, CC 1157, Montevideo, Uruguay.
| | - Dorothea Fiedler
- Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle Strasse 10, 13125, Berlin, Germany.
- Department of Chemistry, Princeton University, Washington Rd., Princeton, New Jersey, 08544, USA.
| |
Collapse
|
59
|
Ghoshal S, Zhu Q, Asteian A, Lin H, Xu H, Ernst G, Barrow JC, Xu B, Cameron MD, Kamenecka TM, Chakraborty A. TNP [N2-(m-Trifluorobenzyl), N6-(p-nitrobenzyl)purine] ameliorates diet induced obesity and insulin resistance via inhibition of the IP6K1 pathway. Mol Metab 2016; 5:903-917. [PMID: 27689003 PMCID: PMC5034689 DOI: 10.1016/j.molmet.2016.08.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 08/10/2016] [Accepted: 08/15/2016] [Indexed: 12/30/2022] Open
Abstract
Objective Obesity and type 2 diabetes (T2D) lead to various life-threatening diseases such as coronary heart disease, stroke, osteoarthritis, asthma, and neurodegeneration. Therefore, extensive research is ongoing to identify novel pathways that can be targeted in obesity/T2D. Deletion of the inositol pyrophosphate (5-IP7) biosynthetic enzyme, inositol hexakisphosphate kinase-1 (IP6K1), protects mice from high fat diet (HFD) induced obesity (DIO) and insulin resistance. Yet, whether this pathway is a valid pharmacologic target in obesity/T2D is not known. Here, we demonstrate that TNP [N2-(m-Trifluorobenzyl), N6-(p-nitrobenzyl)purine], a pan-IP6K inhibitor, has strong anti-obesity and anti-diabetic effects in DIO mice. Methods Q-NMR, GTT, ITT, food intake, energy expenditure, QRT-PCR, ELISA, histology, and immunoblot studies were conducted in short (2.5-week)- and long (10-week)-term TNP treated DIO C57/BL6 WT and IP6K1-KO mice, under various diet and temperature conditions. Results TNP, when injected at the onset of HFD-feeding, decelerates initiation of DIO and insulin resistance. Moreover, TNP facilitates weight loss and restores metabolic parameters, when given to DIO mice. However, TNP does not reduce weight gain in HFD-fed IP6K1-KO mice. TNP specifically enhances insulin sensitivity in DIO mice via Akt activation. TNP decelerates weight gain primarily by enhancing thermogenic energy expenditure in the adipose tissue. Accordingly, TNP's effect on body weight is partly abolished whereas its impact on glucose homeostasis is preserved at thermoneutral temperature. Conclusion Pharmacologic inhibition of the inositol pyrophosphate pathway has strong therapeutic potential in obesity, T2D, and other metabolic diseases. Pharmacologic inhibition of IP6K by TNP, at the onset of high fat feeding, decelerates initiation of DIO and insulin resistance in mice. TNP, when treated to DIO mice, promotes weight loss and restores metabolic homeostasis. TNP does not reduce high fat diet induced weight gain in IP6K1-KO mice. TNP promotes insulin sensitivity by stimulating Akt activity, whereas it reduces body weight primarily by enhancing thermogenic energy expenditure. Long-term TNP treatment does not display deleterious side effects.
Collapse
Key Words
- 5-IP7, diphosphoinositol pentakisphosphate
- ALT, alanine aminotransferase
- AST, aspartate transaminase
- AUC, area under curve
- Akt
- BAT, brown adipose tissue
- CD, chow-diet
- CPT1a, carnitine palmitoyltransferase I
- Cidea, cell death activator-A
- DIO, diet-induced obesity
- Diabetes
- EE, energy expenditure
- EWAT, epididymal adipose tissue
- Energy expenditure
- GSK3, glycogen synthase kinase
- GTT, glucose tolerance test
- H&E, hematoxylin and eosin
- HFD, high-fat diet
- HPLC, high performance liquid chromatography
- IP6K
- IP6K, Inositol hexakisphosphate kinase
- IP6K1-KO, IP6K1 knockout
- ITT, insulin tolerance test
- IWAT, inguinal adipose tissue
- Inositol pyrophosphate
- Obesity
- PCR, polymerase chain reaction
- PGC1α, PPAR coactivator 1 alpha
- PKA, protein kinase A
- PPARγ, peroxisome proliferator-activated receptor gamma
- PRDM16, PR domain containing 16
- Pro-TNP, TNP treatment for protection against DIO
- Q-NMR, quantitative nuclear magnetic resonance
- QRT-PCR, quantitative reverse transcription polymerase chain reaction
- RER, Respiratory exchange ratio
- RWAT, retroperitoneal adipose tissue
- Rev-TNP, long-term TNP treatment for reversal of DIO
- RevT-TNP, Long-term TNP treatment for reversal of DIO at thermoneutral temperature
- S473, serine 473
- S9, serine 9
- SREV-TNP, short-term TNP treatment for reversal of DIO
- T2D, type-2 diabetes
- T308, threonine 308
- TNP, [N2-(m-Trifluorobenzyl), N6-(p-nitrobenzyl)purine]
- UCP-1/3, uncoupling protein 1/3
- VO2, volume of oxygen consumption
- WAT, white adipose tissue
Collapse
Affiliation(s)
- Sarbani Ghoshal
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Qingzhang Zhu
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Alice Asteian
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Hua Lin
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Haifei Xu
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Glen Ernst
- Drug Discovery Division, Lieber Institute for Brain Development, Baltimore, MD 21205, USA
| | - James C Barrow
- Drug Discovery Division, Lieber Institute for Brain Development, Baltimore, MD 21205, USA
| | - Baoji Xu
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Michael D Cameron
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Theodore M Kamenecka
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Anutosh Chakraborty
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, FL 33458, USA.
| |
Collapse
|
60
|
Inositol hexakisphosphate kinase-1 interacts with perilipin1 to modulate lipolysis. Int J Biochem Cell Biol 2016; 78:149-155. [PMID: 27373682 DOI: 10.1016/j.biocel.2016.06.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 05/20/2016] [Accepted: 06/28/2016] [Indexed: 12/21/2022]
Abstract
Lipolysis leads to the breakdown of stored triglycerides (TAG) to release free fatty acids (FFA) and glycerol which is utilized by energy expenditure pathways to generate energy. Therefore, a decrease in lipolysis augments fat accumulation in adipocytes which promotes weight gain. Conversely, if lipolysis is not complemented by energy expenditure, it leads to FFA induced insulin resistance and type-2 diabetes. Thus, lipolysis is under stringent physiological regulation, although the precise mechanism of the regulation is not known. Deletion of inositol hexakisphosphate kinase-1 (IP6K1), the major inositol pyrophosphate biosynthetic enzyme, protects mice from high fat diet (HFD) induced obesity and insulin resistance. IP6K1-KO mice are lean due to enhanced energy expenditure. Therefore, IP6K1 is a target in obesity and type-2 diabetes. However, the mechanism/s by which IP6K1 regulates adipose tissue lipid metabolism is yet to be understood. Here, we demonstrate that IP6K1-KO mice display enhanced basal lipolysis. IP6K1 modulates lipolysis via its interaction with the lipolytic regulator protein perilipin1 (PLIN1). Furthermore, phosphorylation of IP6K1 at a PKC/PKA motif modulates its interaction with PLIN1 and lipolysis. Thus, IP6K1 is a novel regulator of PLIN1 mediated lipolysis.
Collapse
|
61
|
Yang J, Liu Z, Xiao TS. Post-translational regulation of inflammasomes. Cell Mol Immunol 2016; 14:65-79. [PMID: 27345727 PMCID: PMC5214939 DOI: 10.1038/cmi.2016.29] [Citation(s) in RCA: 146] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 05/05/2016] [Accepted: 05/05/2016] [Indexed: 12/16/2022] Open
Abstract
Inflammasomes play essential roles in immune protection against microbial infections. However, excessive inflammation is implicated in various human diseases, including autoinflammatory syndromes, diabetes, multiple sclerosis, cardiovascular disorders and neurodegenerative diseases. Therefore, precise regulation of inflammasome activities is critical for adequate immune protection while limiting collateral tissue damage. In this review, we focus on the emerging roles of post-translational modifications (PTMs) that regulate activation of the NLRP3, NLRP1, NLRC4, AIM2 and IFI16 inflammasomes. We anticipate that these types of PTMs will be identified in other types of and less well-characterized inflammasomes. Because these highly diverse and versatile PTMs shape distinct inflammatory responses in response to infections and tissue damage, targeting the enzymes involved in these PTMs will undoubtedly offer opportunities for precise modulation of inflammasome activities under various pathophysiological conditions.
Collapse
Affiliation(s)
- Jie Yang
- Department of Pathology, Case Western Reserve University, Cleveland, OH 44106-7288, USA.,Graduate Program in Physiology and Biophysics, Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH 44106-7288, USA
| | - Zhonghua Liu
- Department of Pathology, Case Western Reserve University, Cleveland, OH 44106-7288, USA
| | - Tsan Sam Xiao
- Department of Pathology, Case Western Reserve University, Cleveland, OH 44106-7288, USA
| |
Collapse
|
62
|
Thota SG, Bhandari R. The emerging roles of inositol pyrophosphates in eukaryotic cell physiology. J Biosci 2016; 40:593-605. [PMID: 26333405 DOI: 10.1007/s12038-015-9549-x] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Inositol pyrophosphates are water soluble derivatives of inositol that contain pyrophosphate or diphosphate moieties in addition to monophosphates. The best characterised inositol pyrophosphates, are IP7 (diphosphoinositol pentakisphosphate or PP-IP5), and IP8 (bisdiphosphoinositol tetrakisphosphate or (PP)2-IP4). These energy-rich small molecules are present in all eukaryotic cells, from yeast to mammals, and are involved in a wide range of cellular functions including apoptosis, vesicle trafficking, DNA repair, osmoregulation, phosphate homeostasis, insulin sensitivity, immune signalling, cell cycle regulation, and ribosome synthesis. Identified more than 20 years ago, there is still only a rudimentary understanding of the mechanisms by which inositol pyrophosphates participate in these myriad pathways governing cell physiology and homeostasis. The unique stereochemical and bioenergetic properties these molecules possess as a consequence of the presence of one or two pyrophosphate moieties in the vicinity of densely packed monophosphates are likely to form the molecular basis for their participation in multiple signalling and metabolic pathways. The aim of this review is to provide first time researchers in this area with an introduction to inositol pyrophosphates and a comprehensive overview on their cellular functions.
Collapse
Affiliation(s)
- Swarna Gowri Thota
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad 500 001, India
| | | |
Collapse
|
63
|
Deletion of inositol hexakisphosphate kinase 1 (IP6K1) reduces cell migration and invasion, conferring protection from aerodigestive tract carcinoma in mice. Cell Signal 2016; 28:1124-36. [PMID: 27140681 PMCID: PMC4913618 DOI: 10.1016/j.cellsig.2016.04.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 04/20/2016] [Accepted: 04/28/2016] [Indexed: 11/21/2022]
Abstract
Inositol hexakisphosphate kinases (IP6Ks), a family of enzymes found in all eukaryotes, are responsible for the synthesis of 5-diphosphoinositol pentakisphosphate (5-IP7) from inositol hexakisphosphate (IP6). Three isoforms of IP6Ks are found in mammals, and gene deletions of each isoform lead to diverse, non-overlapping phenotypes in mice. Previous studies show a facilitatory role for IP6K2 in cell migration and invasion, properties that are essential for the early stages of tumorigenesis. However, IP6K2 also has an essential role in cancer cell apoptosis, and mice lacking this protein are more susceptible to the development of aerodigestive tract carcinoma upon treatment with the oral carcinogen 4-nitroquinoline-1-oxide (4NQO). Not much is known about the functions of the equally abundant and ubiquitously expressed IP6K1 isoform in cell migration, invasion and cancer progression. We conducted a gene expression analysis on mouse embryonic fibroblasts (MEFs) lacking IP6K1, revealing a role for this protein in cell receptor-extracellular matrix interactions that regulate actin cytoskeleton dynamics. Consequently, cells lacking IP6K1 manifest defects in adhesion-dependent signaling, evident by lower FAK and Paxillin activation, leading to reduced cell spreading and migration. Expression of active, but not inactive IP6K1 reverses migration defects in IP6K1 knockout MEFs, suggesting that 5-IP7 synthesis by IP6K1 promotes cell locomotion. Actin cytoskeleton remodeling and cell migration support the ability of cancer cells to achieve their complete oncogenic potential. Cancer cells with lower IP6K1 levels display reduced migration, invasion, and anchorage-independent growth. When fed an oral carcinogen, mice lacking IP6K1 show reduced progression from epithelial dysplasia to invasive carcinoma. Thus, our data reveal that like IP6K2, IP6K1 is also involved in early cytoskeleton remodeling events during cancer progression. However, unlike IP6K2, IP6K1 is essential for 4NQO-induced invasive carcinoma. Our study therefore uncovers similarities and differences in the roles of IP6K1 and IP6K2 in cancer progression, and we propose that an isoform-specific IP6K1 inhibitor may provide a novel route to suppress carcinogenesis. Gene-expression analysis of Ip6k1 knockout MEFs reveals down-regulation of cell surface-extracellular matrix signaling. Ip6k1 knockout MEFs show reduced adhesion-dependent signaling, cell spreading and migration. Cancer cells deficient in IP6K1 display reduced migration, invasion and anchorage independent growth. Mice lacking IP6K1 are resistant to progression from epithelial dysplasia to invasive carcinoma.
Collapse
|
64
|
Yates LM, Fiedler D. A Stable Pyrophosphoserine Analog for Incorporation into Peptides and Proteins. ACS Chem Biol 2016; 11:1066-73. [PMID: 26760216 DOI: 10.1021/acschembio.5b00972] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Protein pyrophosphorylation is a covalent modification of proteins, mediated by the inositol pyrophosphate messengers. Although the inositol pyrophosphates have been linked to a range of cellular processes, the role of protein pyrophosphorylation remains minimally characterized in vivo. The inherent instability of the phosphoanhydride bond has hampered the development of useful bioanalytical techniques to interrogate this novel signaling mechanism. Here, we describe the preparation of a pyrophosphoserine analog containing a stable methylene-bisphosphonate group that is compatible with solid-phase peptide synthesis. The resulting peptides demonstrate enhanced stability in Eukaryotic cell lysates and mammalian plasma and display resistance toward chemical degradation, when compared to the corresponding pyrophosphopeptides. In addition, the peptides containing the stable pyrophosphoserine analog are highly compatible with common ligation methods, such as native chemical ligation, maleimide conjugation, and glutaraldehyde ligation. The bisphosphonate-containing peptides will, therefore, be well-suited for future pyrophosphoserine antibody generation and affinity capture of pyrophosphoprotein binding partners and provide a key entry point to study the regulatory role of protein pyrophosphorylation.
Collapse
Affiliation(s)
- Lisa M. Yates
- Department
of Chemistry, Princeton University, Washington Rd, Princeton, New Jersey 08544, United States
| | - Dorothea Fiedler
- Department
of Chemistry, Princeton University, Washington Rd, Princeton, New Jersey 08544, United States
- Leibniz-Institut für Molekulare Pharmakologie (FMP), Robert-Rössle-Str. 10, 13125 Berlin, Germany
| |
Collapse
|
65
|
Inositol hexakisphosphate (IP6) generated by IP5K mediates cullin-COP9 signalosome interactions and CRL function. Proc Natl Acad Sci U S A 2016; 113:3503-8. [PMID: 26976604 DOI: 10.1073/pnas.1525580113] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The family of cullin-RING E3 Ligases (CRLs) and the constitutive photomorphogenesis 9 (COP9) signalosome (CSN) form dynamic complexes that mediate ubiquitylation of 20% of the proteome, yet regulation of their assembly/disassembly remains poorly understood. Inositol polyphosphates are highly conserved signaling molecules implicated in diverse cellular processes. We now report that inositol hexakisphosphate (IP6) is a major physiologic determinant of the CRL-CSN interface, which includes a hitherto unidentified electrostatic interaction between the N-terminal acidic tail of CSN subunit 2 (CSN2) and a conserved basic canyon on cullins. IP6, with an EC50 of 20 nM, acts as an intermolecular "glue," increasing cullin-CSN2 binding affinity by 30-fold, thereby promoting assembly of the inactive CRL-CSN complexes. The IP6 synthase, Ins(1,3,4,5,6)P5 2-kinase (IPPK/IP5K) binds to cullins. Depleting IP5K increases the percentage of neddylated, active Cul1 and Cul4A, and decreases levels of the Cul1/4A substrates p27 and p21. Besides dysregulating CRL-mediated cell proliferation and UV-induced apoptosis, IP5K depletion potentiates by 28-fold the cytotoxic effect of the neddylation inhibitor MLN4924. Thus, IP5K and IP6 are evolutionarily conserved components of the CRL-CSN system and are potential targets for cancer therapy in conjunction with MLN4924.
Collapse
|
66
|
Pavlovic I, Thakor DT, Vargas JR, McKinlay CJ, Hauke S, Anstaett P, Camuña RC, Bigler L, Gasser G, Schultz C, Wender PA, Jessen HJ. Cellular delivery and photochemical release of a caged inositol-pyrophosphate induces PH-domain translocation in cellulo. Nat Commun 2016; 7:10622. [PMID: 26842801 PMCID: PMC4743007 DOI: 10.1038/ncomms10622] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 01/05/2016] [Indexed: 02/07/2023] Open
Abstract
Inositol pyrophosphates, such as diphospho-myo-inositol pentakisphosphates (InsP7), are an important family of signalling molecules, implicated in many cellular processes and therapeutic indications including insulin secretion, glucose homeostasis and weight gain. To understand their cellular functions, chemical tools such as photocaged analogues for their real-time modulation in cells are required. Here we describe a concise, modular synthesis of InsP7 and caged InsP7. The caged molecule is stable and releases InsP7 only on irradiation. While photocaged InsP7 does not enter cells, its cellular uptake is achieved using nanoparticles formed by association with a guanidinium-rich molecular transporter. This novel synthesis and unprecedented polyphosphate delivery strategy enable the first studies required to understand InsP7 signalling in cells with controlled spatiotemporal resolution. It is shown herein that cytoplasmic photouncaging of InsP7 leads to translocation of the PH-domain of Akt, an important signalling-node kinase involved in glucose homeostasis, from the membrane into the cytoplasm. Photocaged inositol-pyrophosphates offer a tool to study cellular signalling, but their challenging synthesis has precluded any biological studies so far. Here, the authors report the synthesis and cellular delivery of a photocaged analogue, and show that it mediates protein translocation in cellulo.
Collapse
Affiliation(s)
- Igor Pavlovic
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland
| | - Divyeshsinh T Thakor
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland
| | - Jessica R Vargas
- Departments of Chemistry and Chemical and Systems Biology, Stanford University, Stanford, California 94305, USA
| | - Colin J McKinlay
- Departments of Chemistry and Chemical and Systems Biology, Stanford University, Stanford, California 94305, USA
| | - Sebastian Hauke
- European Molecular Biology Laboratory (EMBL), Cell Biology &Biophysics Unit, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Philipp Anstaett
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland
| | - Rafael C Camuña
- Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Málaga, Malaga 29071, Spain
| | - Laurent Bigler
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland
| | - Gilles Gasser
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland
| | - Carsten Schultz
- European Molecular Biology Laboratory (EMBL), Cell Biology &Biophysics Unit, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Paul A Wender
- Departments of Chemistry and Chemical and Systems Biology, Stanford University, Stanford, California 94305, USA
| | - Henning J Jessen
- Department of Chemistry and Pharmacy, Albert-Ludwigs University Freiburg, Albertstrasse 21, 79104 Freiburg, Germany
| |
Collapse
|
67
|
Thomas MP, Mills SJ, Potter BVL. The "Other" Inositols and Their Phosphates: Synthesis, Biology, and Medicine (with Recent Advances in myo-Inositol Chemistry). Angew Chem Int Ed Engl 2016; 55:1614-50. [PMID: 26694856 PMCID: PMC5156312 DOI: 10.1002/anie.201502227] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Indexed: 12/24/2022]
Abstract
Cell signaling via inositol phosphates, in particular via the second messenger myo-inositol 1,4,5-trisphosphate, and phosphoinositides comprises a huge field of biology. Of the nine 1,2,3,4,5,6-cyclohexanehexol isomers, myo-inositol is pre-eminent, with "other" inositols (cis-, epi-, allo-, muco-, neo-, L-chiro-, D-chiro-, and scyllo-) and derivatives rarer or thought not to exist in nature. However, neo- and d-chiro-inositol hexakisphosphates were recently revealed in both terrestrial and aquatic ecosystems, thus highlighting the paucity of knowledge of the origins and potential biological functions of such stereoisomers, a prevalent group of environmental organic phosphates, and their parent inositols. Some "other" inositols are medically relevant, for example, scyllo-inositol (neurodegenerative diseases) and d-chiro-inositol (diabetes). It is timely to consider exploration of the roles and applications of the "other" isomers and their derivatives, likely by exploiting techniques now well developed for the myo series.
Collapse
Affiliation(s)
- Mark P Thomas
- Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - Stephen J Mills
- Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - Barry V L Potter
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK.
| |
Collapse
|
68
|
Pavlovic I, Thakor DT, Jessen HJ. Synthesis of 2-diphospho-myo-inositol 1,3,4,5,6-pentakisphosphate and a photocaged analogue. Org Biomol Chem 2016; 14:5559-62. [DOI: 10.1039/c6ob00094k] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Diphosphoinositol polyphosphates (inositol pyrophosphates, X-InsP7) are a family of second messengers with important roles in eukaryotic biology. A new approach targeting 2-InsP7 and a photocaged analogue is described.
Collapse
Affiliation(s)
- I. Pavlovic
- Department of Chemistry
- University of Zürich
- 8057 Zürich
- Switzerland
| | - D. T. Thakor
- Department of Chemistry
- University of Zürich
- 8057 Zürich
- Switzerland
| | - H. J. Jessen
- Department of Chemistry and Pharmacy
- Albert-Ludwigs University Freiburg
- 79104 Freiburg
- Germany
| |
Collapse
|
69
|
Thomas MP, Mills SJ, Potter BVL. Die “anderen” Inositole und ihre Phosphate: Synthese, Biologie und Medizin (sowie jüngste Fortschritte in dermyo-Inositolchemie). Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201502227] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Mark P. Thomas
- Department of Pharmacy & Pharmacology; University of Bath; Claverton Down Bath BA2 7AY Vereinigtes Königreich
| | - Stephen J. Mills
- Department of Pharmacy & Pharmacology; University of Bath; Claverton Down Bath BA2 7AY Vereinigtes Königreich
| | - Barry V. L. Potter
- Department of Pharmacology; University of Oxford; Mansfield Road Oxford OX1 3QT Vereinigtes Königreich
| |
Collapse
|
70
|
Inositol Hexakisphosphate Kinase-3 Regulates the Morphology and Synapse Formation of Cerebellar Purkinje Cells via Spectrin/Adducin. J Neurosci 2015; 35:11056-67. [PMID: 26245967 DOI: 10.1523/jneurosci.1069-15.2015] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED The inositol hexakisphosphate kinases (IP6Ks) are the principal enzymes that generate inositol pyrophosphates. There are three IP6Ks (IP6K1, 2, and 3). Functions of IP6K1 and IP6K2 have been substantially delineated, but little is known of IP6K3's role in normal physiology, especially in the brain. To elucidate functions of IP6K3, we generated mice with targeted deletion of IP6K3. We demonstrate that IP6K3 is highly concentrated in the brain in cerebellar Purkinje cells. IP6K3 physiologically binds to the cytoskeletal proteins adducin and spectrin, whose mutual interactions are perturbed in IP6K3-null mutants. Consequently, IP6K3 knock-out cerebella manifest abnormalities in Purkinje cell structure and synapse number, and the mutant mice display deficits in motor learning and coordination. Thus, IP6K3 is a major determinant of cytoskeletal disposition and function of cerebellar Purkinje cells. SIGNIFICANCE STATEMENT We identified and cloned a family of three inositol hexakisphosphate kinases (IP6Ks) that generate the inositol pyrophosphates, most notably 5-diphosphoinositol pentakisphosphate (IP7). Of these, IP6K3 has been least characterized. In the present study we generated IP6K3 knock-out mice and show that IP6K3 is highly expressed in cerebellar Purkinje cells. IP6K3-deleted mice display defects of motor learning and coordination. IP6K3-null mice manifest aberrations of Purkinje cells with a diminished number of synapses. IP6K3 interacts with the cytoskeletal proteins spectrin and adducin whose altered disposition in IP6K3 knock-out mice may mediate phenotypic features of the mutant mice. These findings afford molecular/cytoskeletal mechanisms by which the inositol polyphosphate system impacts brain function.
Collapse
|
71
|
Sun R, Li J, Wang B, Guo Y, Ma L, Quan X, Chu Z, Li T. Liver kinase B1 promoter CpG island methylation is related to lung cancer and smoking. Int J Clin Exp Med 2015; 8:14070-14074. [PMID: 26550370 PMCID: PMC4613055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Accepted: 05/20/2015] [Indexed: 06/05/2023]
Abstract
The aim of this study was to explore the association of CpG islands methylation of liver kinase B1 (LKB1) with primary lung cancer and smoking, providing a theoretical basis for the demethylating drug to treat lung cancer by detecting the LKB1 promoter CpG methylation. mRNA expression of LKB1 were detected by in situ hybridization and methylation status on Hap II locus of the promoter of LKB1 was analyzed by methylation-specific polymerase chain reaction (PCR). 7 of 80 LKB1 positive cases had methylation on CpG islands while 18 of 44 LKB1 negative cases had methylation on CpG islands. The difference was significant between CpG island methylation and LKB1 expression. 8 of 54 cases of early and middle lung cancer were detected LKB1 promoter CpG island methylation while 30 controls were not detected, the difference was significant. 5 of 64 more-than-5-year cases had methylation on CpG islands while 20 of 60 less-than-5-year cases had methylation. The difference was significant between of 5-year survival and CpG island methylation of LKB1. 22 of 74 smoking cases of lung cancer had methylation on CpG islands of LKB1 while only 3 of 50 non-smoking cases had methylation. The difference of smoking and CpG island methylation of LKB1 was significant. LKB1 promoter CpG islands aberrant methylation is closely associated with the occurrence, development and prognosis of lung cancer, especially with smoking history including clinical early diagnosis and prognosis. CpG islands methylation in the promoter of LKB1 is likely important one of the mechanism of smoking-associated lung cancer.
Collapse
Affiliation(s)
- Rongju Sun
- Department of Emergency, General Hospital of PLABeijing 100853, China
- Department of Emergency, Affiliated Hainan Hospital, General Hospital of PLASanya 572000, China
| | - Jie Li
- Department of Thoracic Surgery, General Hospital of PLABeijing 100853, China
| | - Bo Wang
- Department of Thoracic Surgery, General Hospital of PLABeijing 100853, China
| | - Yingfei Guo
- Department of Emergency or Respiration, The First Affiliated Hospital of General Hospital of PLABeijing 100048, China
| | - Lingyun Ma
- Department of Emergency or Respiration, The First Affiliated Hospital of General Hospital of PLABeijing 100048, China
| | - Xiaojiao Quan
- Department of Emergency, Affiliated Hainan Hospital, General Hospital of PLASanya 572000, China
| | - Zhixiang Chu
- Department of Emergency, Affiliated Hainan Hospital, General Hospital of PLASanya 572000, China
| | - Tanshi Li
- Department of Emergency, General Hospital of PLABeijing 100853, China
| |
Collapse
|