TPX2 Protein Research Articles

MiR-218-5p Targeting TPX2 Regulates p53 Pathway and Inhibits Malignant Progression of Lung Adenocarcinoma

Lung adenocarcinoma (LUAD) is a major subtype of lung cancer, and its treatment and diagnosis remain a hot research topic. Targeting protein for Xenopus kinesin-like protein 2 (TPX2) is highly expressed in a variety of cancer cells and may be associated with the progression of LUAD. This study aimed to investigate the effect of TPX2 on the malignant progression of LUAD cells and the regulatory mechanisms. The expression of gene TPX2 in LUAD tissues from The Cancer Genome Atlas (TCGA) database was analyzed by bioinformatics analysis techniques. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression levels of TPX2 and miR-218-5p in human lung normal cell lines and human LUAD cell lines. Western blot was used to detect TPX2 protein expression in cell lines and its effect on the expression of key proteins in the p53 signaling pathway. The relationship between TPX2 and miR-218-5p was predicted using bioinformatics and verified by dual luciferase reporter gene assay. Cell counting kit-8 (CCK-8) assay, cell clone formation, cell scratching, Transwell assay, and flow cytometry were used to detect the effects of miR-218-5p and TPX2 on LUAD cell function. TPX2 was significantly overexpressed in LUAD cells, and knockdown of TPX2 inhibited LUAD cell proliferation, migration, and invasion, promoted apoptosis and induced G2/M phase block, and promoted the expression of key proteins in the p53 signaling pathway. miR-218-5p, an upstream regulator of TPX2, could inhibit its expression. Overexpression of miR-218-5p eliminated the malignant development caused by high expression of TPX2, inhibited the malignant processes of LUAD cells such as proliferation and migration as well as promoted the p53 signaling pathway. miR-218-5p targets and inhibits TPX2 expression and exerts an inhibitory effect on the malignant progression of LUAD cells via p53.

MiRNA-27b-3p/TPX2 Axis Regulates Clear Cell Renal Cell Carcinoma Cell Proliferation, Invasion and Migration.

There is a wide variety of cancer cells that can be linked to the presence of TPX2. However, there is not a lot of evidence regarding its role in the development and maintenance of clear cell renal cell carcinoma (ccRCC). In our study, bioinformatics analysis was performed to obtain differentially expressed mRNAs and miR-NAs in ccRCC. Survival curves predicted correlation of TPX2 expression with patient survival. The upstream regulatory miRNA of TPX2 was predicted to be miRNA-27b-3p through database, and dual luciferase assay verified the targeted relationship. qRT-PCR and Western blot were employed for examination of TPX2 mRNA and protein expression in ccRCC cells. Proliferation, invasion, migration and cell cycle were detected by CCK-8, colony formation, wound healing, Transwell, and flow cytometry assays. The results showed that TPX2 showed very high expression in ccRCC, and patients with higher TPX2 expression had shorter relative survival. Low miRNA-27b-3p expression was found in ccRCC. Knockdown of TPX2 or forced expression of miRNA-27b-3p in ccRCC cells inhibited cell proliferation, migration, invasion, and arrested cell division in G0/G1 phase. Dual luciferase reporter presented that miRNA-27b-3p targeted TPX2 to inhibit its expression. Rescue experiments demonstrated that the miRNA-27b-3p/ TPX2 axis affected the biological functions of ccRCC cells. Concurrent overexpression of miRNA-27b-3p and TPX2 inhibited the facilitating effect of TPX2 on ccRCC cell growth. The results revealed novel regulatory mechanisms involved in ccRCC progression, hoping that it may spark an insight for later discovery about the new therapeutic targets for ccRCC.

KIF4A promotes genomic stability and progression of endometrial cancer through regulation of TPX2 protein degradation.

Kinesin family member 4A (KIF4A) belongs to the kinesin superfamily proteins, which are closely associated with mitophagy. Nonetheless, the role of KIF4A in endometrial cancer (EC) remains poorly characterized. The present study showed that KIF4A not only was upregulated but also predicted poor prognosis in patients with EC. KIF4A knockdown in EC cells resulted in attenuated proliferative capacity in vitro and in vivo. Transcriptome sequencing and gene function analysis revealed that KIF4A contributed to the maintenance of EC cells' genomic stability and that KIF4A knockdown induced the DNA damage response, cell cycle arrest, and apoptosis. Mechanistically, KIF4A interacted with TPX2 (a protein involved in DNA damage repair to cope with the replication pressure) to enhance its stability via inhibition of TPX2 ubiquitination and eventually ensured the genomic stability of EC cells during mitosis. Taken together, our results indicated that KIF4A functions as a tumor oncogene that facilitates EC progression via the maintenance of genomic stability. Therefore, targeting the KIF4A/TPX2 axis may provide new concepts and strategies for the treatment of patients with EC.

MiR-548a-3p Weakens the Tumorigenesis of Colon Cancer Through Targeting TPX2.

Background: MicroRNA (miRNA) has been verified a significant factor to participate in the progression of colon cancer (CC). In this study, the authors investigated the mechanism and function of miR-548a-3p in CC. Materials and Methods: Bioinformatics analysis was used to analyze the mRNA expression profile and miRNA expression profile from GEO data series. The expression of miRNA and mRNA was analyzed by real-time quantification polymerase chain reaction in 43 pairs of CC clinical tissue samples and CC cells. The Western blot assay was used to detect the TPX2 protein. Then, SW480 and HCT116 cells were stably transfected with miR-548a-3p mimic, miR-548a-3p inhibitor, TPX2 overexpression, and TPX2 siRNA constructs to study the effects of miR-548a-3p and TPX2. Cellular functional experiments included cell counting kit-8 assay, BrdU incorporation assay, and wound healing assay. In addition, luciferase reporter assay was applied to detect the regulatory association between miR-548a-3p and TPX2. Results: TPX2 and miR-548a-3p were identified as the interested mRNA and miRNA by microarray analysis. In CC tissues and cell lines, miR-548a-3p with low expression and TPX2 with high expression were observed. What's more, exogenous overexpressed miR-548a-3p impaired the cell viability, cell proliferation, and cell migration, while TPX2 overexpression enhanced the malignancy phenotypes. However, the promotion effect of TPX2 on CC cells was impaired by miR-548a-3p. Conclusion: This study revealed that miR-548a-3p attenuated the development of CC by targeting TPX2.

Knockdown of circ_0003340 induces cell apoptosis, inhibits invasion and proliferation through miR-564/TPX2 in esophageal cancer cells

Circular RNA (circRNA) is a promising biomarker of cancer occurrence and development. The different expression levels of circRNAs in various cancers also make them possible therapeutic targets. In this work, we researched the function and underlying mechanisms of circ_0003340 (circ3340) in esophageal cancer EC1 and EC9706 cells. Firstly, we found the expression levels of circ3340 are higher in ESCC and two esophageal cancer cells than in adjacent normal tissues and Het-1a cells. Bioinformatics analysis showed circ3340 has a binding site with miR-564. This was verified by luciferase assay, which revealed that miR-564 can be sponged by circ3340, and that the TPX2 3′UTR is a direct target of miR-564. Upregulation of miR-564 decreased TPX2 protein levels, as shown by Western blot. Moreover, knockdown of circ3340 or enhancement of miR-564 expression had similar effects in EC1 and EC9706 cells, i.e., inducing cell apoptosis, inhibiting cell proliferation, and arresting cell invasion. Downregulation of circ3340 had a negative influence on EC1 and EC9706 cells by affecting the miR-564/TPX2 pathway. Additionally, animal experiments revealed that downregulation of circ3340 inhibited tumor growth in vivo, making circ3340 a potential therapeutic target for patients with esophageal squamous cell cancer.

TPX2 silencing exerts anti‑tumor effects on hepatocellular carcinoma by regulating the PI3K/AKT signaling pathway.

Hepatocellular carcinoma (HCC) is one of the primary causes of cancer-associated deaths worldwide. Current treatment methods include surgical resection, chemotherapy and radiotherapy; however the curative rate remains low, thus novel treatments are required. The aim of the present study was to investigate the role of targeting protein for Xenopus kinesin-like protein 2 (TPX2) in the growth of HCC and its underlying molecular mechanism. Immunohistochemistry staining, reverse transcription-quantitative (RT-q)PCR and western blotting were used to detect the expression of TPX2 mRNA and protein in liver cancer tissue samples, adjacent normal liver tissue samples, and the HCC cell lines Huh7, Hep3B, PLC/PRF/5 and MHCC97-H. The recombinant plasmid pMagic4.1-shRNA-TPX2 was constructed and transfected into Huh7 and Hep3B HCC cells to silence TPX2 expression. The proliferation, apoptosis, migration and invasion of Huh7 cells and Hep3B cells were evaluated before and after TPX2 silencing. The mRNA and protein expression levels of multiple signaling pathway-associated genes were detected by RT-qPCR and western blotting. The expression levels of TPX2 mRNA and protein were significantly higher in HCC tissue samples compared with adjacent normal liver tissue sample. TPX2 mRNA and protein expression levels were detected in the different HCC cell lines. The recombinant plasmid pMagic4.1-shRNA-TPX2 was successfully transfected into Huh7 and Hep3B cells, resulting in TPX2 silencing. TPX2 knockdown significantly reduced cell proliferation, cell migration and cell invasion of Huh7 and Hep3B cells, whilst also increasing the rate of apoptosis in these cells. Following TPX2 silencing, the expression levels of PI3K, phospho-AKT, Bcl-2, c-Myc and Cyclin D1 were significantly decreased, whereas the expression levels of P21 and P27 were significantly increased. In conclusion, TPX2 may suppress the growth of HCC by regulating the PI3K/AKT signaling pathway and thus, TPX2 may be a potential target for the treatment of liver cancer.

TPX2 as a Novel Prognostic Indicator and Promising Therapeutic Target in Triple-negative Breast Cancer

IntroductionTriple-negative breast cancer (TNBC), which lacks endocrine therapies and targeted therapies, has the worst prognosis of all breast cancers which remain the most common malignancy in women worldwide. Targeting protein for xenopus kinesin-like protein 2 (TPX2) is a microtubule-associated protein that is strongly correlated with chromosomal instability, resulting in the development of different human tumors. Herein, we investigated the relationship between the clinical outcome of TNBC and the expression level of the TPX2 protein. Materials and MethodsPatients initially treated at Tongji Hospital for confirmed TNBC were evaluated by immunohistochemical staining and retrospectively recruited into our study. The immunohistochemical staining evaluation of TPX2 was based on the staining intensity and extent. STATA was used to analyze all the data. ResultsIn total, 97 patients with TNBC were recruited into our study. The TPX2 protein was overexpressed in almost all patients with TNBC. Our study demonstrated that an elevated TPX2 protein level was significantly associated with worse outcomes in the patients with TNBC, including worse progression-free survival (PFS) and overall survival (OS) (log-rank test, P < .001). Our model also indicated that TPX2 expression was an independent predictor of OS (hazard ratio, 2.20; 95% confidence interval, 1.13-4.28; P = .020) but not of PFS (P = .639). ConclusionIn conclusion, we demonstrated that TPX2 could be a novel prognostic marker of PFS and OS after the initial treatment of TNBC. We also revealed that TPX2 expression could serve as an independent predictor of OS but not of PFS and a promising therapeutic target in patients with TNBC.

Gain of native conformation of Aurora A S155R mutant by small molecules.

Aurora A is a mitotic serine/threonine kinase protein that is a proposed target of the first-line anticancer drug design. It has been found to be overexpressed in many human cancer cells, including hematological, breast, and colorectal. Here, we focus on a particular somatic mutant S155R of Aurora kinase A protein, whose activity decreases because of loss of interaction with a TPX2 protein that results in ectopic expression of the Aurora kinase A protein, which contributes chromosome instability, centrosome amplification, and oncogenic transformation. The primary target of this study is to select a drug molecule whose binding results in gaining S155R mutant interaction with TPX2. The computational methodology applied in this study involves mapping of hotspots (for uncompetitive binding), virtual screening, protein-ligand docking, postdocking optimization, and protein-protein docking approach. In this study, we screen and validate ZINC968264, which acts as a potential molecule that can improve the loss of function occurred because of mutation (S155R) in Aurora A. Our approaches pave a suitable path to design a potential drug against physiological condition manifested because of S155R mutant in Aurora A.

Co-Expression Network Analysis and Hub Gene Selection for High-Quality Fiber in Upland Cotton (Gossypium hirsutum) Using RNA Sequencing Analysis.

Upland cotton (Gossypium hirsutum) is grown for its elite fiber. Understanding differential gene expression patterns during fiber development will help to identify genes associated with fiber quality. In this study, we used two recombinant inbred lines (RILs) differing in fiber quality derived from an intra-hirsutum population to explore expression profiling differences and identify genes associated with high-quality fiber or specific fiber-development stages using RNA sequencing. Overall, 72/27, 1137/1584, 437/393, 1019/184, and 2555/1479 differentially expressed genes were up-/down-regulated in an elite fiber line (L1) relative to a poor-quality fiber line (L2) at 10, 15, 20, 25, and 30 days post-anthesis, respectively. Three-hundred sixty-three differentially expressed genes (DEGs) between two lines were colocalized in fiber strength (FS) quantitative trait loci (QTL). Short Time-series Expression Miner (STEM) analysis discriminated seven expression profiles; gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation were performed to identify difference in function between genes unique to L1 and L2. Co-expression network analysis detected five modules highly associated with specific fiber-development stages, especially for high-quality fiber tissues. The hub genes in each module were identified by weighted gene co-expression network analysis. Hub genes encoding actin 1, Rho GTPase-activating protein with PAK-box, TPX2 protein, bHLH transcription factor, and leucine-rich repeat receptor-like protein kinase were identified. Correlation networks revealed considerable interaction among the hub genes, transcription factors, and other genes.

Prognostic and clinical value of Targeting protein for Xenopus kinesin-like protein 2 in patients with gastrointestinal tract cancers: A meta-analysis.

Accumulating studies have indicated that Targeting protein for Xenopus kinesin-like protein 2 (TPX2) was overexpressed in various types of human cancers. However, the prognostic and clinical value of TPX2 in gastrointestinal (GI) tract cancers was not well-understood. This study was aimed to comprehensively explore the prognostic and clinical significance of TPX2 in GI tract cancers. Eligible studies were systematically retrieved in PubMed, Embase, Web of Science, China National Knowledge Infrastructure (CNKI) and Wanfang database. The eligible studies were collected to evaluate the association of TPX2 with prognosis and clinicopathological features, with the pooling hazard ratio (HR) and odds ratio (OR) with 95% confidence interval (CI). The meta-analysis suggested that overexpression of TPX2 protein was significantly correlated with poor overall survival (OS) (HR: 2.20, 95% CI: 1.60-2.80, P <.001) in GI tract cancers, the subgroup meta-analysis also confirmed the prognostic value of TPX2 protein. Furthermore, clinical significances of TPX2 protein in gastric cancer were discussed. Upregulated TPX2 protein was correlated with poor clinical outcomes, suggesting that TPX2 protein can serve as a promising predictive biomarker in patients with GI tract cancers.

Abstract B03: Targeting the KIF11/KIF15/TPX2 axis to develop new therapies for ovarian cancer

Abstract Unlimited genetic and epigenetic diversity across the patient population, and within the tumor and among metastatic lesions of an individual patient, presents a challenge in developing targeted therapies to treat epithelial ovarian cancer (EOC). To find the Achilles heel of ovarian cancers, we designed an RNAi-based screen (&amp;gt;6,000 genes) to identify points of molecular vulnerability. These screens identified KIF11 as essential to maintain tumor cell viability. KIF11 encodes kinesin Eg5 (KIF11), a motor protein required for microtubule antiparallel sliding during mitosis that has been targeted clinically. Although KIF11 inhibitors are well tolerated by EOC patients, clinical response rates were disappointing in heavily treated patients with advanced disease. We hypothesize one mechanism through which KIF11 inhibitors’ efficacy is muted is via functional compensation of mitotic spindle assembly by KIF15, a second motor kinesin. Using a synthetic lethal approach, we have shown that RNAi-mediated silencing of KIF15 has no effect on cell viability, but significantly sensitized cells by &amp;gt;10- to 100-fold to a class of KIF11 inhibitors (KIF11is). TPX2-targeted siRNAs reduce cell viability by 5-fold alone, and sensitize cells by 100-fold in the presence of KIF11i. Based on these observations, we designed a high-throughput screening assay using Alpha Technology©. Informed by previous predictions of KIF15-TPX2 binding domains, we designed peptides corresponding to the appropriate domains of KIF15 (aa1149-1388, GST-tagged) and TPX2 (aa346-747, His-tagged), for use in the AlphaScreen© assay. Following several optimization steps (e.g., buffer selection, protein titration, TruHits© assay validation), we demonstrate that KIF15 binds TPX2, producing a signal &amp;gt;30-fold greater than background signal. Further, peptides designed to mimic either KIF15 or TPX2 binding domains, but not scrambled controls, exhibited concentration-dependent disruption of the KIF15-TPX2 interaction. Next, we screened a FDA library (3,474 compounds) and bioactive (1,902 compounds) library and identified 122 hits; fresh compound stocks were tested at 4 concentrations (20, 10, 5, and 2.5 μM), resulting in 53 confirmed hits (28 FDA, 25 bioactive). To identify false positives that interfere with assay chemistry, we repeated the screen at 3 concentrations, replacing the His-TPX2 and GST-KIF15 proteins with a His-GST fusion. As an orthogonal screen, we performed a Homogenous Time Resolved Fluorescence© (HTRF)-based screen to reconfirm hit compounds at the aforementioned concentrations. From these combined data, we have identified 4 hit compounds (KU-P001 to KU-P004) that disrupt KIF15/TPX2 protein-protein interactions. To further prioritize our hits, we developed in vitro (EOC cell lines were exposed to increasing concentrations, up to 1 µM, of KIF11i for 4 months) and in vivo (patient-derived ascites xenograft models of EOC were treated with 3 cycles of either 5 mg/kg or 10 mg/kg of a KIF11i and were serially passaged and treated for 3 additional generations) models of KIF11i-resistance to evaluate their activities. In resistant EOC cells we observed a 3-fold increase in KIF15 protein expression as compared with parental cells; TPX2 protein expression remained unchanged. In vivo, both KIF15 (68% increase) and TPX2 (2-fold) protein expression was increased in resistant versus untreated PDX tumor cells. Combination studies of KU-P004 and ispinesib (KIF11i) in vitro revealed a 2- to 64-fold increase in cell death for both responsive and resistant EOC cells compared with KIF11i treatment alone. In summary, we have developed a high-throughput screening assay platform to identify inhibitors of the KIF15-TPX2 interaction and are using iterative medicinal chemistry to guide optimization and functional evaluation of hits and lead compounds to develop new combination therapies for women with ovarian cancer. Citation Format: Rebecca J. Wates, Anuradha Roy, Frank Schoenen, John Karanicolas, Scott Weir, Andrew Godwin. Targeting the KIF11/KIF15/TPX2 axis to develop new therapies for ovarian cancer. [abstract]. In: Proceedings of the AACR Conference: Addressing Critical Questions in Ovarian Cancer Research and Treatment; Oct 1-4, 2017; Pittsburgh, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(15_Suppl):Abstract nr B03.

Targeted TPX2 increases chromosome missegregation and suppresses tumor cell growth in human prostate cancer.

Prostate cancer is a complex disease that can be relatively harmless or extremely aggressive. Although androgen-deprivation therapy is a commonly used treatment for men with prostate cancer, the adverse effects can be detrimental to patient health and quality of life. Therefore, identifying new target genes for tumor growth will enable the development of novel therapeutic intervention. TPX2 plays a critical role in chromosome segregation machinery during mitosis. Low rates of chromosome missegregation can promote tumor development, whereas higher levels might promote cell death and suppress tumorigenesis. Hence, the strategy of promoting cell death by inducing massive chromosome missegregation has been a therapeutic application for selectively eliminating highly proliferating tumor cells. RNAi was used for TPX2 protein expression knockdown, and a clonogenic assay, immunostaining, double thymidine block, image-cytometry analysis, and tumor spheroid assay were used to analyze the role of TPX2 in tumor cell growth, cell cycle progression, multinuclearity, ploidy, and tumorigenicity, respectively; finally, Western blotting was used to analyze anticancer mechanisms in TPX2 targeting. We demonstrated that targeting TPX2 reduced cell cycle regulators and chromosome segregation genes, resulting in increased cell micronucleation. Moreover, TPX2 depletion led to prostate cancer cell growth inhibition, increased apoptosis, and reduced tumorigenesis. These results confirmed the therapeutic potential of targeting TPX2 in prostate cancer treatment. Moreover, we found that TPX2 silencing led to deregulation of CDK1, cyclin B, securin, separase, and aurora A proteins; by contrast, p21 mRNA was upregulated. We also determined the molecular mechanisms for TPX2 targeting in prostate cancer cells. In conclusion, our study illustrates the power of TPX2 as a potential novel target gene for prostate cancer treatment.

Effects of TPX2 gene on radiotherapy sensitization in breast cancer stem cells.

The present study explored the link between the targeting protein for Xenopus kinesin-like protein 2 (TPX2) gene and breast tumor stem cells in order to screen novel radiosensitizers. Expression of TPX2 protein and gene in breast cancer cells was analyzed by western blot analysis and RT-PCR. Three kinds of broad-spectrum sensitizers were selected and their effects on radiotherapy were analyzed by immunohistochemistry in breast tumor stem cells. TPX2 gene and protein were expressed in breast tumor cells and increased gradually along with the expression of cancer cell differentiation; 25 mg/l lovastatin showed best radio-sensitizing effects on breast cancer cells. Furthermore, immunohistochemical results showed that the positive rate of breast cancer cells processed by 25 mg/l lovastatin were significantly decreased. In conclusion, TPX2 gene is closely related to the development of breast cancer stem cells. Moreover, the sensitizing effects of lovastatin on breast tumor stem cells are the result of its influence on the TPX2 gene.

Sinup is essential for the integrity of centrosomes and mitotic spindles in zebrafish embryos

ABSTRACTFish lineage-specific gene, sinup [Siaz-interacting nuclear protein], modulates neural plate formation in embryogenesis and shares homology with human TPX2 protein, a member of the vertebrate mitogen-activating protein family. In spite of the presence of the TPX2 domain in Sinup, its cellular function has been unknown. As an initial approach to this question, we expressed Sinup by injecting sinup-EGFP mRNAs into zebrafish embryos at the one- to two-cell stage. First of all, Sinup-EGFP was associated with centrosomes and mitotic spindles. In particular, Sinup was localized to the spindle poles and midbody microtubules during the period between anaphase and cytokinesis. Second, various deleted mutants of Sinup-EGFP failed to be associated with the centrosomes and mitotic spindles. Third, a Sinup mutant, where the 144th Serine residue was converted to alanine, not only disturbed the mitotic spindle organization, such as multipolar spindles, fragmented spindle poles, and flattened spindles, but also arrested the cell cycle at metaphase and cell movement. Finally, Sinup is phosphorylated by Aurora A and the 144th Serine mutant of Sinup is partially phosphorylated by Aurora A kinase. We thus propose that Sinup is an essential element for the integrity of centrosomes and mitotic spindle fibers as well as for the normal process of cell cycle and cellular movement in vertebrate embryos.

TPX2 expression is associated with poor survival in gastric cancer

BackgroundTargeting protein for Xenopus kinesin-like protein 2 (TPX2) is a microtubule-associated protein required for microtubule formation in human cells. Several studies have demonstrated that TPX2 is overexpressed in multiple tumor types and promotes tumor growth and metastasis. However, there have been few reports regarding its role in gastric cancer. In this study, we evaluated TPX2 expression and investigated its correlations with gastric cancer clinicopathological features and prognosis.MethodsTumor samples were obtained from 290 patients with gastric adenocarcinoma who had undergone gastrectomy. The expression of TPX2 protein was examined using immunohistochemical staining. TPX2 messenger RNA (mRNA) levels were evaluated using real-time quantitative reverse transcription PCR in 19 of the gastric cancer tumors and adjacent normal tissues.ResultsThe mRNA levels of TPX2 were significantly higher in gastric cancer tissues than in matched adjacent normal tissues (p = 0.004). In the immunohistochemical analysis, TPX2 overexpression was found in 123 (42.4%) of 290 patients. High TPX2 expression was positively associated with age, type of histology, depth of tumor, lymph node metastasis, stage, and remote metastasis or recurrence. High TPX2 expression was significantly associated with poorer disease-specific survival (p = 0.004) and relapse-free interval (p = 0.013).ConclusionsOur results indicated that high TPX2 expression was associated with tumor progression and poor survival in gastric cancer.

Expression of microtubule-associated protein TPX2 in human gastric carcinoma and its prognostic significance.

BackgroundThe molecular mechanisms underlying the development and progression of gastric carcinoma remain poorly understood. The main objective of this study was to investigate the expression level of targeting protein for Xenopus kinesin-like protein 2 (TPX2) and its clinical significance in human gastric carcinoma.MethodsReal-time quantitative polymerase chain reaction (RT-PCR) and western blotting were used to determine the mRNA and protein levels of TPX2 in 20 paired gastric carcinoma tissues and the adjacent normal tissues, and the expression of TPX2 protein in 106 specimens of a gastric carcinoma tissue microarray was determined by immunohistochemistry. The associations of TPX2 expression with the clinicopathological features were analyzed, and the prognosis of gastric carcinoma patients was evaluated.ResultsThe results showed that the expression of TPX2 mRNA was significantly higher in gastric carcinoma than in the adjacent normal tissues in 20 paired samples. Western blotting analysis revealed that TPX2 protein was differentially increased in 17 of 20 specimens from primary human gastric carcinoma tissues compared with those from adjacent non-tumor tissues. Immunohistochemical staining showed that TPX2 over-expression was significantly associated with advanced age (P = 0.001) and tumor T stage (P = 0.003). In addition, TPX2 was an independent prognostic factor for overall survival (OS) in the multivariate analysis [hazard ratio (HR) 0.001; 95 % confidence interval (CI) 2.626–7.198; P = 0.001].ConclusionsTPX2 is up-regulated in gastric carcinoma and is associated with old age and tumor T stage. TPX2 may serve as a good prognostic indicator in patients with gastric carcinoma.Electronic supplementary materialThe online version of this article (doi:10.1186/s12935-016-0357-7) contains supplementary material, which is available to authorized users.

TPX2 in human clear cell renal carcinoma: Expression, function and prognostic significance.

Targeting protein for Xenopus kinesin-like protein 2 (TPX2) is a microtubule-associated protein. TPX2 is considered to be an important gene in tumorigenesis; however, the particular function of TPX2 in the development of human renal cell carcinoma (RCC) is unknown. In the present study, the expression, function and prognostic significance of TPX2 in human RCC was analyzed. A total of 286 tissue samples from patients with RCC who had undergone nephrectomies were utilized. Subsequently, the expression of TPX2 protein was investigated using immunohistochemistry and western blotting, and TPX2 mRNA expression was examined using reverse transcription-quantitative polymerase chain reaction. To establish the effect of TPX2 on the proliferation and invasion of the RCC cells, TPX2 expression was increased by stable transfection with a TPX2 vector and TPX2 expression was decreased using small interfering RNA. Proliferation of the RCC cells was analyzed using a WST-1 assay and an animal xenograft model with BALB/c nude mice, whilst invasion of the RCC cells was examined using a Matrigel-coated invasion chamber. It was demonstrated that TPX2 expression was significantly higher in the RCC tissues compared with normal kidney tissues (P<0.05). Furthermore, TPX2 expression was associated with tumor size, histological grade and tumor stage (P<0.05), and was observed to markedly increase the proliferation and invasion of the RCC cells. It may be concluded that the expression of TPX2 is significantly upregulated in RCC tissue, subsequently increasing the proliferative and invasive ability of RCC cells. Therefore, the protein may serve as a therapeutic target and independent prognostic factor in the treatment of human RCC.

Xenopus LAP2β protein knockdown affects location of lamin B and nucleoporins and has effect on assembly of cell nucleus and cell viability.

Xenopus LAP2β protein is the single isoform expressed in XTC cells. The protein localizes on heterochromatin clusters both at the nuclear envelope and inside a cell nucleus. The majority of XLAP2β fraction neither colocalizes with TPX2 protein during interphase nor can be immunoprecipitated with XLAP2β antibody. Knockdown of the XLAP2β protein expression in XTC cells by synthetic siRNA and plasmid encoded siRNA resulted in nuclear abnormalities including changes in shape of nuclei, abnormal chromatin structure, loss of nuclear envelope, mislocalization of integral membrane proteins of INM such as lamin B2, mislocalization of nucleoporins, and cell death. Based on timing of cell death, we suggest mechanism associated with nucleus reassembly or with entry into mitosis. This confirms that Xenopus LAP2 protein is essential for the maintenance of cell nucleus integrity and the process of its reassembly after mitosis.Electronic supplementary materialThe online version of this article (doi:10.1007/s00709-015-0861-y) contains supplementary material, which is available to authorized users.

TPX2 knockdown suppressed hepatocellular carcinoma cell invasion via inactivating AKT signaling and inhibiting MMP2 and MMP9 expression.

Targeting protein for Xenopus kinesin-like protein 2 (TPX2) is a nuclear proliferation-related protein that plays a critical role in the formation of mitotic spindle. High expression of TPX2 has been observed in several types of tumors. However, the role of TPX2 in hepatocellular carcinoma (HCC) remains unclear. Our study aimed to investigate the effect of TPX2 on HCC cell invasion. The immortalized normal human liver cell line L02 and six HCC cell lines including SMMC-7721, BEL-7402, Huh-7, HepG2, Hep3B and SKHep1 were subjected to qRT-PCR and western blot for TPX2 mRNA and protein, respectively. Furthermore, TPX2 small interfering RNA (siRNA) was used to knock down TPX2 expression in SMMC-7721 and HepG2 cells. Cell proliferation and invasion were determined by MTT and transwell assays. Otherwise, expression of p-AKT, MMP2 and MMP9 were evaluated by western blot in SMMC-7721 cells. The expression of TPX2 in HCC cell lines was markedly higher than that in normal human liver cell line. TPX2 knockdown using a specific TPX2-siRNA reduced the number of invaded cells and inhibited cell proliferation in SMMC-7721 and HepG2 cells. Furthermore, TPX2 knockdown resulted in inactivation of AKT signaling and down-regulation of MMP2 and MMP9 expression in SMMC-7721 cells. Our study identified that TPX2 might contribute to tumor cell invasion through activating AKT signaling and subsequently increasing MMP2 and MMP9 in HCC.

Upregulation of the TPX2 gene is associated with enhanced tumor malignance of esophageal squamous cell carcinoma

PurposeTo explore the expression of TPX2 and its significance in esophageal squamous cell carcinoma (ESCC) tissue and approach relationship between the TPX2 and clinicopathological characteristic of esophageal squamous cell carcinoma. MethodRT-PCR and immunohistochemical staining were used to compare the expression of TPX2 in 62 esophageal squamous cell carcinoma, 31 atypical hyperplasia and 62 normal esophageal mucosa. ResultsIn ESCC, atypical hyperplasia and in normal mucous membrane tissues, the positive rate of TPX2 protein expression was 85.5% (53/62), 51.6% (16/31) and 4.8% (3/62); the positive rate of TPX2 mRNA expression was 65.5% (40/62), 35.5 (11/31) and 4.83% (3/62). The expression of TPX2 protein and mRNA were correlated with invasive depth and lymphatic metastasis of ESCC (P<0.01). ConclusionsOverexpression of TPX2 may be risk factor of lymph node in esophageal carcinoma, and maybe a potential biomarker for early diagnosis and prognosis of esophageal squamous cell carcinoma.