Targeting Protein For Xklp2 Expression Research Articles

Identification of prognostic and therapeutic biomarkers in type 2 papillary renal cell carcinoma

BackgroundPapillary renal cell carcinoma (PRCC) can be divided into type 1 (PRCC1) and type 2 (PRCC2) and PRCC2 share a more invasive phenotype and worse prognosis. This study aims to identify potential prognostic and therapeutic biomarkers in PRCC2.MethodsA cohort from The Cancer Genome Atlas and two datasets from Gene Expression Omnibus were examined. Common differentially expressed genes (DEGs) were screened and potential biomarkers were explored by using Kaplan–Meier method and cox regression analysis. Functional enrichment analysis was utilized to evaluate the potential biological functions. Tumor infiltrating immune cells were estimated by CIBERSORT algorithm. Ninety-two PRCC2 samples from Fudan University Shanghai Cancer Center were obtained, and immunostaining was performed to validate prognostic and therapeutic significance of the potential biomarker.ResultsPRCC2 has worse overall survival and shares distinct molecular characteristics from PRCC1. There was significant higher expression level of Targeting protein for Xklp2 (TPX2) in PRCC2 compared with normal tissues. Higher expression level of TPX2 was significantly associated with worse overall survival in PRCC2 and kinesin family genes expression were found significantly elevated in high risk PRCC2. Abundance of tumor infiltrating M1 macrophage was significantly higher in PRCC2 and it was also associated with worse overall survival. In the FUSCC cohort, higher TPX2 expression was significantly correlated with worse overall and progression-free survival. Retrospective analysis indicated that mTOR inhibitor (everolimus) had greater efficacy in the high-risk group than in the low-risk group (overall response rate: 28.6% vs. 16.7%) and that everolimus had greater efficacy than sunitinib in the high-risk group (overall response rate: 28.6% vs. 20%).ConclusionsTPX2 was a prognostic and therapeutic biomarker in PRCC2. Higher abundance of tumor infiltrating M1 macrophage was significantly associated with worse overall survival in PRCC2. mTOR inhibitors may have good efficacy in patients with high-risk PRCC2.

Comprehensive Analysis of the Oncogenic Role of Targeting Protein for Xklp2 (TPX2) in Human Malignancies.

Mitosis and spindle assembly require the microtubule-associated protein Xenopus kinesin-like protein 2 (TPX2). Although TPX2 is highly expressed in several malignant tumor forms, little is known about its role in cancer. In this study, we performed the gene set enrichment analysis of TPX2 in 33 types of cancers and an extensive pan-cancer bioinformatic analysis using prognosis, tumor mutational burdens, microsatellite instability, tumor microenvironment, and immune cell infiltration data. According to the differential expression study, TPX2 was found to be overexpressed across all studied cancer types. Based on the survival analysis, increased TPX2 expression was associated with a poor prognosis for most cancers. The TPX2 expression level was confirmed to correlate with the clinical stage, microsatellite instability, and tumor mutational burden across all cancer types. Furthermore, TPX2 expression has been linked to tumor microenvironments and immune cell infiltration, particularly in bladder urothelial carcinoma, liver hepatocellular carcinoma, lung adenocarcinoma, stomach adenocarcinoma, and uterine corpus endometrial carcinoma. Finally, the gene set enrichment analysis implicated TPX2 in the regulation of aminoacyl tRNA biosynthesis, which is the most important tumor cell cycle signaling pathway. This comprehensive pan-cancer analysis shows that TPX2 is a prognostic molecular biomarker for most cancers and suggests its potential as an effective therapeutic target for the treatment of these diseases.

Identification of early stage recurrence endometrial cancer biomarkers using bioinformatics tools.

Endometrial cancer (EC) is the sixth most common cancer in women worldwide. Early diagnosis is critical in recurrent EC management. The present study aimed to identify biomarkers of EC early recurrence using a workflow that combined text and data mining databases (DisGeNET, Gene Expression Omnibus), a prioritization algorithm to select a set of putative candidates (ToppGene), protein-protein interaction network analyses (Search Tool for the Retrieval of Interacting Genes, cytoHubba), association analysis of selected genes with clinicopathological parameters, and survival analysis (Kaplan-Meier and Cox proportional hazard ratio analyses) using a The Cancer Genome Atlas cohort. A total of 10 genes were identified, among which the targeting protein for Xklp2 (TPX2) was the most promising independent prognostic biomarker in stage I EC. TPX2 expression (mRNA and protein) was higher (P<0.0001 and P<0.001, respectively) in ETS variant transcription factor 5-overexpressing Hec1a and Ishikawa cells, a previously reported cell model of aggressive stage I EC. In EC biopsies, TPX2 mRNA expression levels were higher (P<0.05) in high grade tumors (grade 3) compared with grade 1–2 tumors (P<0.05), in tumors with deep myometrial invasion (>50% compared with <50%; P<0.01), and in intermediate-high recurrence risk tumors compared with low-risk tumors (P<0.05). Further validation studies in larger and independent EC cohorts will contribute to confirm the prognostic value of TPX2.

Aurora A kinase and its activator TPX2 are potential therapeutic targets in KRAS-induced pancreatic cancer.

Oncogenic KRAS mutations are found in over 90% of pancreatic ductal adenocarcinomas (PDACs). As yet, however, no effective therapies are available for KRAS-induced malignancies. Therefore, research aimed at the identification of KRAS targets with therapeutic potential is warranted. Our goal was to investigate Aurora A (AURKA) and targeting protein for Xklp2 (TPX2) as potential therapeutic targets in PDAC. AURKA and TPX2 expression was assessed using RNAseq and qRT-PCR in PDAC patient samples and matched non-tumor pancreatic tissues. Publicly available PDAC datasets were used to investigate associations of AURKA and TPX2 expression levels with patient survival and the presence of KRAS mutations. Next, we used an Aurora kinase inhibitor, or KRAS, AURKA and TPX2 targeting using RNA interference in KRAS-mutant PDAC cells and, subsequently, analyzed their clonogenic and anchorage-independent growth and migration. We found that relative to matched non-tumor tissues, PDAC tumors displayed significantly higher expression levels of AURKA and TPX2. In addition, we found that AURKA and TPX2 were co-expressed in PDAC datasets, and that high expression levels of AURKA and TPX2 were associated with a shorter patient survival and with the presence of oncogenic KRAS mutations. In addition, we found that siRNA-mediated KRAS targeting in KRAS-mutant PDAC cells reduced AURKA and TPX2 expression. Furthermore, targeting AURKA or TPX2 in KRAS-mutant PDAC cells reduced their clonogenic and anchorage-independent growth, as well their migration. From our data we conclude that AURKA and TPX2 may act as KRAS biomarkers in PDAC that can predict a worse prognosis, and that AURKA or TPX2 targeting in PDAC cells may reduce their transformed phenotype. These results indicate that AURKA and TPX2 may serve as promising targets to be explored for KRAS-mutant PDAC therapy.

Effect and mechanism of lentivirus-mediated silencing of TPX2 gene on proliferation and apoptosis of human hepatoma cells.

This study aimed to investigate the role and mechanism of action of targeting protein for Xklp2 (TPX2) in liver cancer, we compared TPX messenger RNA (mRNA) expression in liver cancer tissue samples and adjacent normal liver tissue samples as well as in human liver cancer cell lines and nonmalignant cell line by quantitative reverse transcription polymerase chain reaction (qRT-PCR). TPX2 gene was silenced in HepG2 cells by transfection with the lentiviral vector expressing TPX2-targeting short hairpin RNA (shRNA), and the knockdown efficiency was evaluated by RT-qPCR. Cell proliferation, apoptosis as well as protein level of c-Myc, cyclin D1, caspase-3, phosphorylated glycogen synthase kinase-3β (p-GSK-3β), and β-catenin in HepG2 cells were evaluated before and after the TPX2 knockdown. Wnt/β-catenin signaling pathway was inhibited by treatment with 20 μM of XAV-939 or activated by treatment with 20 mM of LiCl. We found that TPX2 mRNA level was significantly increased in liver cancer tissue samples and cell lines comparing to noncancerous counterparts (P < 0.05). TPX2 knockdown significantly reduces TPX2 expression (P < 0.01), cell proliferation (P < 0.05), protein level of c-Myc and cyclin D1 (P < 0.01), activation of Wnt/β-catenin signaling in HepG2 cells (P < 0.01) while increasing cell apoptosis (P < 0.01). Treatment with XAV-939 significantly reduced HepG2 cell proliferation (P < 0.05) while increasing cell apoptosis (P < 0.01). Treatment with LiCl significantly attenuated the antiproliferative and apoptosis-promoting effect of TPX2 knockdown on HepG2 cells (P < 0.05). Lentivirus-mediated silencing of TPX2 gene could inhibit proliferation and induce apoptosis in hepatoma cells by inhibiting Wnt signaling pathway and regulating cyclin and apoptosis-related proteins.

Prognostic role of targeting protein for Xklp2 in solid tumors: A PRISMA-compliant systematic review and meta-analysis.

The prognostic role of targeting protein for Xklp2 (TPX2) in solid tumors has been investigated in several researches, but the results remain controversial. Here we present a meta-analysis to systematically review the association between TPX2 expression levels and prognosis of human solid tumors. Studies published until December 2017 were searched in PubMed, Web of Science, and EBSCO, 13 studies (2134 patients) were collected for analysis. Odds ratios (ORs) for overall survival (OS) and disease-free survival (DFS) from individual studies were calculated by the application of Mantel-Haenszel random effect model. Pooled ORs were estimated by Z test. Publication bias and interstudy heterogeneity analyses were also performed. TPX2 overexpression was associated with poor OS at 3 and 5 years [OR = 4.63, 95% confidence interval (CI): 3.27-6.56, P < .00001; OR = 4.05, 95% CI: 2.32-7.07, P < .00001, respectively] of solid tumors. Similar results were observed with DFS at 3 and 5 years (OR = 3.35, 95% CI: 1.83-6.14, P < .0001; OR = 2.94, 95% CI: 1.74-4.98, P < .0001, respectively). Subgroup analysis revealed that increased TPX2 expression was related to worse prognosis of gastric cancer and hepatocellular cancer, while irrelevant to esophageal squamous cell cancer at 5-year survival rate. Overexpression of TPX2 is related to poor survival rate in most solid tumors, which indicates that the expression level of TPX2 is a significant prognostic parameter and potential therapeutic target in various solid tumors.

TPX2 as a prognostic indicator and potential therapeutic target in clear cell renal cell carcinoma

ObjectivesOur aims were to determine if targeting protein for Xklp2 (TPX2) is correlated with clear cell renal cell carcinoma (ccRCC) histology and oncologic outcomes using The Cancer Genome Atlas (TCGA) and an institutional tissue microarray (TMA). MethodsClinicopathological data obtained from the TCGA consisted of 415 samples diagnosed with ccRCC. A TMA was constructed from tumors of 207 patients who underwent radical nephrectomy for ccRCC. TPX2 expression by immunohistochemistry on TMA was assessed by a genitourinary pathologist. Clinical data were extracted and linked to TMA cores. TPX2 and Aurora-A mRNA coexpression were evaluated in the TCGA cohort. Overall survival (OS), cancer-specific survival, and recurrence-free survival (RFS) were analyzed using the Kaplan-Meier method and log-rank statistics. Univariate and multivariate analyses were conducted using Cox proportional hazard models. ResultsMedian follow-up time for the TCGA cohort was 3.07 years. Aurora-A and TPX2 mRNA coexpression were significantly correlated (Pearson correlation = 0.918). High TPX2 mRNA expression was associated with advanced stage, metastasis, poor OS, and RFS.Median follow-up time for the TMA cohort was 5.3 years. Elevated TPX2 protein expression, defined as greater than 75th percentile staining intensity, was identified in 47/207 (22.7%) patients. Increased TPX2 immunostaining was associated with poor OS (P = 0.0327, 53% 5-year mortality), cancer-specific survival (P<0.01, 47.8% 5-year cancer-specific mortality), RFS (P = 0.0313, 73.6%, 5-year recurrence rate), grade, T stage, and metastasis. Multivariate analysis demonstrated elevated expression served as an independent predictor of RFS (hazard ratio = 3.62 (1.13–11.55), P = 0.029). ConclusionsWe show TPX2, a regulator of Aurora-A, is associated with high grade and stage of ccRCC, and is an independent predictor of recurrence. Future studies are warranted testing its role in ccRCC biology, and its potential as a therapeutic target.

Overexpressed targeting protein for Xklp2 (TPX2) serves as a promising prognostic marker and therapeutic target for gastric cancer

ABSTRACTThe targeting protein for Xenopus kinesin-like protein 2 (TPX2) is a putative oncogene in different human cancers. This study assessed TPX2 expression in gastric cancer tissue samples and then determined the effects of TPX2 knockdown on the regulation of gastric cancer cell malignant behaviors in vitro. Tissue samples from 115 gastric cancer patients were analyzed for TPX2 expression. The effects of TPX2 siRNA on gastric cancer cells were assessed in vitro, including cell viability, cell cycle distribution, apoptosis, migration, and invasion. The data showed that TPX2 was overexpressed in gastric cancer tissues compared to that in the adjacent normal epithelia. Moreover, TPX2 overexpression was associated with a poor overall survival and was an independent prognostic predictor of gastric cancer. In addition, the in vitro study further confirmed the ex vivo data, i.e., knockdown of TPX2 expression reduced gastric cancer cell viability but induced apoptosis and arrested cells at the G2/M phase of the cell cycle. Knockdown of TPX2 expression also inhibited the tumor cell migration and invasion capacity in vitro. At the gene level, knockdown of TPX2 expression upregulated the levels of cyclin B1, cdk4, p53, Bax, caspase-3, and E-cadherin, but downregulated the levels of cyclin D1, cdk2, N-cadherin, slug, matrix metalloprotease (MMP)-2, and MMP-9, suggesting that knockdown of TPX2 expression suppressed tumor cell epithelial–mesenchymal transition (EMT). This study demonstrated that detection of TPX2 overexpression could serve as a prognostic marker and therapeutic target for gastric cancer.

TPX2 regulates neuronal morphology through kinesin-5 interaction.

TPX2 (targeting protein for Xklp2) is a multifunctional mitotic spindle assembly factor that in mammalian cells localizes and regulates mitotic motor protein kinesin-5 (also called Eg5 or kif11). We previously showed that upon depletion or inhibition of kinesin-5 in cultured neurons, microtubule movements increase, resulting in faster growing axons and thinner dendrites. Here, we show that depletion of TPX2 from cultured neurons speeds their rate of process outgrowth, similarly to kinesin-5 inhibition. The phenotype is rescued by TPX2 re-expression, but not if TPX2's kinesin-5-interacting domain is deleted. These results, together with studies showing a spike in TPX2 expression during dendritic differentiation, suggest that the levels and distribution of TPX2 are likely to be determinants of when and where kinesin-5 acts in neurons.

TPX2 Level Correlates with Hepatocellular Carcinoma Cell Proliferation, Apoptosis, and EMT.

Targeting protein for Xklp2 (TPX2) is a microtubule-associated protein involved in targeting the motor protein Xklp2 to microtubules. TPX2 overexpression plays a key role in the progression of human cancers. But the underlying mechanism remains unclear. This study aimed to investigate the effects and mechanisms of TPX2 on the cell cycle, apoptosis, and epithelial-mesenchymal transition (EMT) in hepatocellular carcinoma (HCC). The tissue TPX2 mRNA and protein were assessed by quantitative reverse transcriptase PCR and immunoblot. Cell proliferation, cell cycle, apoptosis, and invasion were determined by CCK-8, FACS, TdT-UTP nick end-labeling, and transwell assays. Immunoblotting was performed to detect the expression of target proteins. TPX2 was highly expressed in tumor tissues compared with non-tumoral tissues, and TPX2 overexpression was positively correlated with poor prognosis. Knockdown TPX2 effectively reduced cell growth, G2/M arrest, induced apoptosis and cell death, and inhibited EMT. Mechanistically, in the TPX2-siRNA-treated groups, cell-cycle-related proteins cyclin A1, cyclin B1, cyclin E1, and cdk4 were up-regulated, while cyclin D1, cdk2, and p21 proteins were down-regulated. Cell-apoptosis-related proteins Bax, p53, caspase-3, and caspase-8 levels were increased. EMT-related proteins E-cadherin was up-regulated, while N-cadherin, β-catenin, MMP-9, MMP-2, and Slug were down-regulated. We also found that knockdown TPX2 in HCC cell lines caused a significant decrease in the level of p-Akt and p-ERK which are important signaling pathways in tumor formation. TPX2 expression is associated with proliferation, apoptosis, and EMT in hepatocellular carcinoma cell and patients.

Abstract LB-214: Common genomic alterations in malignant peripheral nerve sheath tumors augment Aurora A activity and sensitize tumors to aurora kinase inhibitors.

Abstract Malignant peripheral nerve sheath tumours (MPNST) are rare, hereditary, cancers associated with mutations in the neurofibromin 1 gene 1. MPNSTs are often resistant to chemotherapies and have high rates of disease recurrence, highlighting the lack of effective treatment options for this cancer. Aurora kinase A inhibitors (AKIs) have shown promise against MPNST cell lines 2. We expanded this study by testing AKI in human MPNST xenotransplant mice models. Treatment resulted in stabilized disease with tumor cells undergoing senescence and endoreduplication. Aurora kinase A (AURKA) is an emerging target in cancer, however, targeted therapies can often fail in the clinic due to insufficient knowledge about factors that determine tumor response. Therefore, we utilized three MPNST cell lines and profiled them for the expression and activity of AURKA as well as their responses to AKIs. The most proliferative lines, S462 and 2884, express equivalent levels of AURKA, however, S462 cells were more sensitive to kinase inhibition. Both cell lines experienced apoptosis, senescence and endoreduplication in response to AKI treatment. AURKA activity is regulated by a co-activator, the Targeting Protein for XKlp2 (TPX2) and a molecular brake, the Receptor for Hyaluronan Mediated Motility (RHAMM)3. Interestingly, published analysis of copy number variation has identified hemizygous loss of the RHAMM gene in half of the examined high-grade MPNST, but not in benign or low grade tumors 4. We proposed that MPNSTs with RHAMM deletions are oncogene addicted to AURKA activity and are therefore, particularly susceptible to AKI. We profiled our MPNST lines for RHAMM and TPX2 expression and found that S462 cells express significantly more TPX2 and less RHAMM compared to 2884 cells. Furthermore, S462 cells had increased kinase. To determine whether levels of these molecular regulators could affect AKI efficacy we depleted RHAMM and TPX2 in 2884 and S462 cells respectively. While cells with reduced TPX2 have unchanged responses to AKIs, RHAMM depleted cells have a 2 fold reduction in IC-50s. We also looked at the effect of AKI against a population of MPNST tumor-initiating cells (TICs) from the S462 line. Compared to adherent cells, S462 TICs have elevated AURKA activity and their ability to self-renew in vitro is arrested by AKI. Indeed, the altered levels of kinase activity in the RHAMM and TPX2 depletion lines correlated with their ability to form and maintain sphere culture. In addition, we find that AKI treated S462 TICs differentiated into terminal neurons. All in all, these data indicate AURKA as a rational therapy for aggressive MPNSTs with RHAMM serving as a biomarker for AKI efficacy. Citation Format: Pooja Mohan, Joan Castellsague, Jihong Jiang, Kristi Allen, Helen Chen, Oksana Nemirovsky, Melanie Spyra, Kaiji Hu, Lan Kluwe, Miguel Pujana, Alberto Villanueva, Victor Mautner, Sandra Dunn, Jonathan Keats, Conxi Lazaro, Christopher Maxwell. Common genomic alterations in malignant peripheral nerve sheath tumors augment Aurora A activity and sensitize tumors to aurora kinase inhibitors. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-214. doi:10.1158/1538-7445.AM2013-LB-214

Validation of TPX2 as a Potential Therapeutic Target in Pancreatic Cancer Cells

The targeting protein for Xklp2 (TPX2) has recently gained attention as a putative oncogene possibly amplified in several human malignancies, including pancreatic adenocarcinoma. In this work, we sought to evaluate the copy number and expression of TPX2 in pancreatic cancer cell lines and tumor tissues and to further explore the potential of TPX2 as a therapeutic target. The DNA copy number and expression of the TPX2 gene were surveyed in pancreatic cancer cell lines and tumor tissues and compared with those of immortalized normal pancreatic ductal cells and normal pancreatic tissues. The cellular effects of TPX2 knockdown using small interfering RNA oligonucleotides in pancreatic cancer cells, such as growth in tissue culture, in soft agar, and in nude mice; apoptosis; and sensitivity to paclitaxel, were also investigated using various assays. Low-copy-number TPX2 amplification was found in pancreatic cancer cell lines and low-passage pancreatic cancer tumor xenografts. TPX2 expression was upregulated in pancreatic cancer cell lines at both the mRNA and protein levels relative to the immortalized pancreatic ductal epithelial cell line HPDE6. Immunohistochemical staining of a tissue microarray showed that TPX2 expression was higher in pancreatic tumors compared with their normal counterparts. Treatment with TPX2 targeting small interfering RNAs effectively reduced pancreatic cancer cell growth in tissue culture, induced apoptosis, and inhibited growth in soft agar and in nude mice. Knockdown of TPX2 also sensitized pancreatic cancer cells to paclitaxel treatment. Our results suggest that TPX2 might be an attractive target for pancreatic cancer therapy.

TPX2 expression and its significance in squamous cell carcinoma of lung

To study the expression of targeting protein for Xklp2 (TPX2) and its significance in squamous cell carcinoma (SCC) of the lung. Two SCC cell lines and 4 immortalized bronchial epithelial cell lines (as a precancerous model) were examined by Western blot for TPX2 expression. Reverse transcription-polymerase chain reaction analysis for TPX2 was also performed using tumor tissues from 21 patients with SCC of the lung. The expression of TPX2 was studied by immunohistochemistry (using tissue microarray) on paraffin-embedded sections of pulmonary SCC and corresponding precancerous lesions from a group of 319 patients. TPX2 was variably expressed in all the cell lines studied. Compared with matched controls using normal lung tissue, high level of TPX2 mRNA was detected in 16 of the 21 SCC tumor tissue samples analyzed. Immunohistochemical study showed that TPX2 was mainly present in tumor tissues but not in normal controls. The expression of TPX2 correlated with tumor grade, stage and nodal status. As for precancerous lesions, the level of TPX2 was also increased, in accordance with the degree of dysplasia. Expression of TPX2 may play a role in carcinogenesis of bronchial epithelium and tumor progression of pulmonary SCC. It may also represent a potential biomarker for surveillance of SCC of lung.

Expression of targeting protein for xklp2 associated with both malignant transformation of respiratory epithelium and progression of squamous cell lung cancer.

Expression of targeting protein for Xklp2 (TPX2), a microtubule-associated protein, is tightly cell cycle regulated. Abnormally expressed TPX2 has been reported in various malignancies, but less is known in lung cancer. The present study appraised the significance of TPX2 aberrant expression for tumorigenesis and progression of human squamous cell carcinoma (SCC) in lung. The expressive status of TPX2 was firstly examined with lung cancer (L, PAa, and PG) and immortalized bronchial epithelial (C45, M-BE, Tr, and Y-BE) cell lines, and TPX2 expression was detected at both RNA and protein levels by reverse transcription-PCR and Western blotting, respectively. Immunofluorescence staining on M-BE cells showed that the subcellular localization of TPX2 protein is in nucleus at interphase and mitotic spindle at metaphase. Immunohistochemical analyses were subsequently done on the precancerous lesions derived from 114 patients and the tumor tissues of 432 patients with SCC in lung. Extremely low levels of TPX2 protein were found in the normal bronchial epithelia and alveoli, whereas gradually increased TPX2 protein levels were observed in the squamous metaplasia, dysplasia, carcinoma in situ, and invasive tumor tissues. Statistical analysis showed that the TPX2 immunohistochemistry labeling index was correlated with the differentiation grade, stage, and lymphous metastasis of SCC in lung and that TPX2 overexpression is significantly associated with decreased 5-year survival rate of the patients. Aberrant expression of TPX2 may play important role(s) in both malignant transformation of respiratory epithelium and progression of squamous cell lung cancer and could serve as a prognostic predictor for the disease.