High Expression Of TPX2 Research Articles

Integrated Bioinformatic Analysis Reveals the Oncogenic, Survival, and Prognostic Characteristics of TPX2 in Hepatocellular Carcinoma.

Targeting protein for Xenopus kinesin-like protein 2 (TPX2), a well-known mitotic protein, has been linked to carcinogenesis in several cancers. This study investigated the role of TPX2 in hepatocellular carcinoma (HCC) from various aspects using bioinformatic analyses. TPX2 expression and its prognostic value in pan-cancers were analyzed using SangerBox. TPX2 expression and its association with prognosis, immune infiltration, tumor mutations, and signaling pathways in HCC were analyzed using UALCAN, BoxKaplan-Meier Plotter, GEPIA, Human Protein Atlas, TIMER 2.0, and SangerBox. Genes co-expressed with TPX2 in HCC were analyzed using the HCCDB database, followed by functional enrichment using SangerBox. Clinical predictive models were established based on TPX2 and its co-expressed genes using the ACLBI database. TPX2 expression significantly increased in pan-cancers and was associated with survival in nearly half of the cancer types. High TPX2 expression has been linked to poor survival outcomes in patients with HCC. TPX2 expression was positively correlated with abundant infiltration of immune cells (including B cells, CD4 + /CD8 + T cells, macrophages, neutrophils, and dendritic cells), TP53 mutation, and carcinogenesis-related pathways, such as the PI3K/AKT/mTOR pathway, cellular response to hypoxia, and tumor proliferation signature. Nineteen genes were found to be co-expressed with TPX2 in HCC, and these genes showed close positive correlations and were mainly implicated in cell cycle-related functions. A prognostic model established using TPX2 and its expressed genes could stratify HCC patients into high- and low-risk groups, with a significantly shorter survival time in high-risk groups. The prognostic model performed well in predicting 1-, 3-, and 5-year survival of patients with HCC, with areas under the curve of 0.801, 0.725, and 0.711, respectively. TPX2 functions as an oncogene in HCC, and its high expression is detrimental to the survival of patients with HCC. Thus, TPX2 may be a prognostic biomarker and potential therapeutic target for HCC.

High TPX2 expression results in poor prognosis, and Sp1 mediates the coupling of the CX3CR1/CXCL10 chemokine pathway to the PI3K/Akt pathway through targeted inhibition of TPX2 in endometrial cancer.

Approximately 30% of individuals with advanced EC have unsatisfactory prognosis. Evidence suggests that TPX2 is frequently upregulated in malignancies and related to cancer progression. Its role and pathological mechanism in EC need further research. GSEA and TPX2 expression, GO, KEGG, and prognostic analyses were performed with TCGA data by bioinformatic approaches. Relationships between TPX2 expression and clinicopathological parameters were investigated immunohistochemically and statistically. shRNA and overexpression plasmids were constructed and transfected into AN3CA and Ishikawa cells to evaluate phenotypic changes and injected into nude mouse axillae. Coimmunoprecipitation and chromatin immunoprecipitation were used to identify interacting proteins and promoter-binding sequences. Changes in TPX2 expression were identified by Western blotting and RT-qPCR. TPX2 expression was significantly higher in EC tissues than in normal tissues in TCGA and in-house specimens (all p < 0.001). In survival analysis, high TPX2 expression was associated with poor prognosis (p = 0.003). TPX2 overexpression stimulated cancer cell proliferation, promoted the G0-G1-to-G2/M transition, enhanced invasion and migration, and accelerated tumor growth in nude mice. TPX2 regulated the CX3CR1/CXCL10 chemokine pathway and activated the PI3K/Akt signaling pathway. Sp1 negatively regulated TPX2 expression, affecting the malignant progression of endometrial cancer cells by coupling the CX3CR1/CXCL10 chemokine pathway to the PI3K/Akt signaling pathway. TPX2 could be a prognostic biomarker for EC and play an important role in the CX3CR1/CXCL10 chemokine pathway and PI3K/Akt pathway via Sp1.

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.

TPX2 expression as a negative predictor of gemcitabine efficacy in pancreatic cancer

BackgroundTargeting protein for Xenopus kinesin-like protein 2 (TPX2) overexpression in human tumours is associated with increased malignancy. Its effect on gemcitabine resistance in pancreatic ductal adenocarcinoma (PDAC) has not been studied yet.MethodsThe prognostic impact of TPX2 expression was examined in the tumour tissue of 139 patients with advanced PDAC (aPDAC) treated within the AIO-PK0104 trial or translational trials and of 400 resected PDAC (rPDAC) patients. The findings were validated using RNAseq data of 149 resected PDAC patients.ResultsIn the aPDAC cohorts, 13.7% of all samples showed high TPX2 expression, conferring significantly shorter progression-free survival (PFS, HR 5.25, P < 0.001) and overall survival times (OS, HR 4.36, P < 0.001) restricted to gemcitabine-based treated patients (n = 99). In the rPDAC cohort, 14.5% of all samples showed high TPX2 expression, conferring significantly shorter disease-free survival times (DFS, HR 2.56, P < 0.001) and OS times (HR 1.56, P = 0.04) restricted to patients treated with adjuvant gemcitabine. RNAseq data from the validation cohort confirmed the findings.ConclusionsHigh TPX2 expression may serve as a negative predictor of gemcitabine-based palliative and adjuvant chemotherapy in PDAC and could be used to inform clinical therapy decisions.Clinical trial registryThe clinical trial registry identifier is NCT00440167.

MiR-29c Suppresses the Malignant Phenotype of Hepatocellular Carcinoma Cells In Vitro by Mediating TPX2 Associated with Immune Infiltration.

miR-29-3p, an important tumor suppressor, with inhibitory effects in multiple cancers that have been studied. Its exact molecular function is in HCC, however, still not been explored clearly. The purpose of our study is to make certain how miR-29c-3p affects HCC through TPX2. Expression profile data of miR-29c-3p and TPX2 were acquired and downloaded from the TCGA database, and the respective differential expression was verified by qPCR and immunohistochemistry. The StarBase and dual luciferase reporter confirmed TPX2 targeting miR-29c-3p. Their effects on the biological functions of Hep3B and HepG2 were investigated by cellular assays. miR-29-3p was found to be significantly down-regulated in HCC, and the miR-29-3p low expression group had a poor prognosis. Overexpression of miR-29-3p was detrimental to invasion and migration ability of HCC cells and promoted their apoptosis. We identified miR-29c-3p targeting TPX2 by predictive analysis. TPX2 was significantly upregulated in HCC, and patients with high TPX2 expression had a poor prognosis. TPX2 knockdown partially counteracted the promoting effect of miR-29-3p inhibition on hepatocellular carcinoma cells, and its effect on hepatocellular carcinoma cell biology was similar to miR-29c-3p overexpression. miR-29c, a key gene regulating HCC, is lowly expressed in HCC, its overexpression can remarkably inhibit the biological function of tumor cells. miR-29c can perform this function by regulating the expression of TPX2.

PARP1 proximity proteomics reveals interaction partners at stressed replication forks.

PARP1mediates poly-ADP-ribosylation of proteins on chromatin in response to different types of DNA lesions. PARP inhibitors are used for the treatment of BRCA1/2-deficient breast, ovarian, and prostate cancer. Loss of DNA replication fork protection is proposed as one mechanism that contributes to the vulnerability of BRCA1/2-deficient cells to PARP inhibitors. However, the mechanisms that regulate PARP1 activity at stressed replication forks remain poorly understood. Here, we performed proximity proteomics of PARP1 and isolation of proteins on stressed replication forks to map putative PARP1 regulators. We identified TPX2 as a direct PARP1-binding protein that regulates the auto-ADP-ribosylation activity of PARP1. TPX2 interacts with DNA damage response proteins and promotes homology-directed repair of DNA double-strand breaks. Moreover, TPX2 mRNA levels are increased in BRCA1/2-mutated breast and prostate cancers, and high TPX2 expression levels correlate with the sensitivity of cancer cells to PARP-trapping inhibitors. We propose that TPX2 confers a mitosis-independent function in the cellular response to replication stress by interacting with PARP1.

TPX2 regulated by miR-29c-3p induces cell proliferation in osteosarcoma via the AKT signaling pathway.

The present study aimed to investigate the significance of targeting protein for Xenopus kinesin-like protein 2 (TPX2) expression in osteosarcoma. First, the TPX2 expression and survival analysis data were evaluated from The Cancer Genome Atlas (TCGA) database. Next, reverse transcription-quantitative PCR was used to explore the expression of TPX2 in osteosarcoma tissues. The observed potential target relationship between TPX2 and microRNA (miR)-29c-3p was verified using TargetScan and luciferase reporter assays. Kaplan-Meier survival analysis was used to determine associations between TPX2 expression levels and survival prognosis. TPX2 small interfering RNA was successfully constructed and transfected into osteosarcoma cell lines. The effects of TPX2 on osteosarcoma cell proliferation were then detected by MTT assay. In addition, the expression levels of AKT signaling pathway-associated proteins were identified by western blot analysis. The expression of TPX2 was upregulated and the expression of miR-29c-3p was downregulated in osteosarcoma. High expression of TPX2 was linked to a poor prognosis. Using luciferase assay and the miRNA mimic and inhibitors, miR-29c-3p was able to target and repress TPX2, and siRNA knockdown of TPX2 resulted in the inhibition of osteosarcoma cell proliferation by affecting the AKT pathway. Overall, the study showed that miR-29c-3p could inhibit the proliferation of osteosarcoma cells via TPX2 downregulation, and that TPX2 and miR-29c-3p may serve as promising prognostic indicators.

TPX2 is a prognostic marker and promotes cell proliferation in neuroblastoma.

Targeting protein for Xenopus kinesin-like protein 2 (TPX2) is upregulated in various tumors, and several studies have demonstrated the role of TPX2 as a prognostic marker in cancer. However, the function of TPX2 in neuroblastoma (NB) has not been completely elucidated. In the present study, the clinical significance and functional role of TPX2 in NB was investigated. The Therapeutically Applicable Research to Generate Effective Treatments (TARGET)-NB dataset was used. A total of 43 patients with NB were enrolled in the present study as the validation set. After evaluating the prognostic role of TPX2, the combined predictive effect of TPX2 and MYCN proto-oncogene bHLH transcription factor (MYCN) gene amplification was assessed. Double immunofluorescence staining for TPX2 and N-Myc was used to analyze colocalization, and multiple cell function tests were performed by means of in vitro experiments to elucidate the functional role of TPX2 using RNA interference technology in NB cell lines. In both the TARGET-NB set and the validation set, it was found that upregulated of TPX2 was significantly associated with poor overall survival (OS) in patients with NB. The expression of TPX2 was higher in NB patients with MYCN gene amplification, and NB patients with high TPX2 expression and MYCN gene amplification had the poorest OS compared with patients with low TPX2 expression or a single copy of MYCN. In vitro experiments indicated that TPX2 positively regulated cell proliferation and the cell cycle, and promoted cell survival by increasing the resistance to apoptosis. The colocalization of TPX2 with N-Myc in NB cells and tissue was observed. The findings of the present study indicate that TPX2 plays an oncogenic role in NB development and may be a potential prognostic indicator in patients with NB.

High nuclear TPX2 expression correlates with TP53 mutation and poor clinical behavior in a large breast cancer cohort, but is not an independent predictor of chromosomal instability

BackgroundTargeting Protein for Xenopus Kinesin Like Protein 2 (TPX2) is a microtubule associated protein that functions in mitotic spindle assembly. TPX2 also localizes to the nucleus where it functions in DNA damage repair during S-phase. We and others have previously shown that TPX2 RNA levels are strongly associated with chromosomal instability (CIN) in breast and other cancers, and TPX2 RNA levels have been demonstrated to correlate with aggressive behavior and poor clinical outcome across a range of solid malignancies, including breast cancer.MethodsWe perform TPX2 IHC on a cohort of 253 primary breast cancers and adopt a clinically amenable scoring system to separate tumors into low, intermediate, or high TPX2 expression. We then correlate TPX2 expression against diverse pathologic parameters and important measures of clinical outcome, including disease-specific and overall survival. We link TPX2 expression to TP53 mutation and evaluate whether TPX2 is an independent predictor of chromosomal instability (CIN).ResultsWe find that TPX2 nuclear expression strongly correlates with high grade morphology, elevated clinical stage, negative ER and PR status, and both disease-specific and overall survival. We also show that increased TPX2 nuclear expression correlates with elevated ploidy, supernumerary centrosomes, and TP53 mutation. TPX2 nuclear expression correlates with CIN via univariate analyses but is not independently predictive when compared to ploidy, Ki67, TP53 mutational status, centrosome number, and patient age.ConclusionsOur findings demonstrate a strong correlation between TPX2 nuclear expression and aggressive tumor behavior, and show that TPX2 overexpression frequently occurs in the setting of TP53 mutation and elevated ploidy. However, TPX2 expression is not an independent predictor of CIN where it fails to outperform existing clinical and pathologic metrics.

Potential effects of TPX2 in clinicopathologic features, prognosis and metastasis of gastric cancer patients

The over expression of the microtubule-associated protein TPX2 was significantly involved in the progression of many types solid malignancy, and its overexpression is associated with poor clinical outcome. However, it is still unknown the association of TPX2 expression with the prognosis of gastric cancer patients. The expression of TPX2 was determined by qRT-PCR and immunohistochemistry in gastric tissues after surgery. The association of TPX2 with clinicopathologic features, prognosis and metastasis was analysed. TPX2 expression was elevated in gastric cancer tissues compared with matched adjacent noncancerous tissues, and TPX2 expression was closely associated with tumor stage and lymph node metastasis in gastric cancer. Kaplan-Meier survival curves indicated that high TPX2 expression was significantly associated with worse overall survival and metastasis free survival (P=0.0025). Our results suggest that TPX2 is associated with poor prognosis in gastric cancer patients and further study needs in the future to determine TPX2 may represent a prognostic biomarker and therapeutic target for the gastric cancer.

Abstract P3-09-01: MYC dysregulates mitotic spindle function in triple-negative breast cancer creating a dependency on TPX2

Abstract Tumors that overexpress the MYC oncogene, including most receptor triple-negative breast cancers, frequently demonstrate aneuploidy, numerical chromosome alterations associated with highly aggressive cancers. Aneuploidy is also associated with rapid tumor evolution and poor patient outcome. We identify that MYC overexpression induces reversible defects in microtubule nucleation and mitotic spindle assembly, in TNBCs and other epithelial cells, promoting chromosome segregation defects, micronuclei and chromosomal instability (CIN). High TPX2 expression is permissive for mitotic spindle assembly and chromosome segregation in cells with MYC overexpression; whereas TPX2 depletion blocks mitotic progression, induces cell death and prevents tumor growth. Attenuating MYC expression reverses mitotic defects, even in established breast tumor cell lines, implicating an ongoing role for high MYC in the persistence of CIN in cancers. Our studies implicate the MYC oncogene as a regulator of spindle assembly and identify a new MYC-TPX2 synthetic-lethal interaction in TNBC that could represent a future therapeutic strategy in MYC-overexpressing cancers. Moreover, our studies suggest that blocking MYC activity can attenuate the emergence of CIN and tumor evolution. Citation Format: Goga A, Rohrberg J, Corella A, Taileb M, Kilinc S, Jokisch M-L, Camarda R, Zhou A, Balakrishnan S, Chang AN, Klein-Connolly H. MYC dysregulates mitotic spindle function in triple-negative breast cancer creating a dependency on TPX2 [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-09-01.

Abstract 1462: The oncogene MYC induces chromosomal instability through dysregulating mitotic progression evoking a dependency on TPX2

Abstract More than 70% of common solid tumors are aneuploid. Aneuploidy has been implicated in tumorigenesis for decades. A direct cause of aneuploidy is chromosomal instability (CIN) that fuels tumor evolution by providing a heterogeneous subpopulation of cells that contributes to the lethal outcome of cancer, metastasis, therapeutic failure, and drug resistance. The oncogene c-MYC is overexpressed in many cancers and has been shown to induce structural and numerical chromosomal aberrations and aneuploidy. While the role of MYC in overcoming the G1/S checkpoint is well established, the role of MYC in altering mitotic dynamics and eliciting CIN remains poorly understood. Here, we identify a direct influence of increased MYC expression on mitotic progression and spindle assembly. We observe MYC-dependent microtubule nucleation and polymerization defects in mitosis. MYC overexpression induces altered spindle morphology promoting chromosome segregation defects resulting in micronuclei formation, CIN and aneuploidy. Importantly, attenuation of MYC expression reverses the mitotic defects observed, even in established tumor cell lines, implicating an ongoing role for MYC in the persistence of a CIN phenotype in tumors. Gene expression data reveal that MYC regulates numerous genes involved in mitosis, kinetochore function and microtubule behavior. We performed a screen to identify microtubule regulators required for the survival of MYC overexpressing cells. MYC overexpressing cells are reliant on high TPX2 expression, a master microtubule regulator. High TPX2 expression is permissive for mitotic spindle assembly and chromosome segregation in MYC high cells, while TPX2 depletion attenuates cell viability and tumor growth in vivo. Our data suggest that TPX2 is a transcriptional target of MYC. We postulate that high levels of TPX2 are required to tolerate mitotic stress induced by MYC. TPX2 compensates for impaired mitotic progression and prevents the development of physiologically intolerable levels of CIN. High levels of TPX2 might be required for tumors with oncogene-induced mitotic stress to faithfully proceed through mitosis providing an explanation for the abundant upregulation of TPX2 in cancer. Thus, we describe a conditional role for MYC in altering spindle assembly and dynamics, resulting in a dependency on TPX2 for tumor survival. Citation Format: Julia Rohrberg, Alexandra Corella, Moufida Taileb, Marie-Lena Jokisch, Roman Camarda, Sanjeev Balakrishnan, Alicia Zhou, Andrei Goga. The oncogene MYC induces chromosomal instability through dysregulating mitotic progression evoking a dependency on TPX2 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1462.

Overexpression of TPX2 is associated with progression and prognosis of prostate cancer.

Targeting protein for Xenopus kinesin-like protein 2 (TPX2) activates Aurora kinase A during mitosis and targets its activity to the mitotic spindle, serving an important role in mitosis. It has been associated with different types of cancer and is considered to promote tumor growth. The aim of the present study was to explore the role of TPX2 in diagnosing prostate cancer (PCa). It was identified that TPX2 expression in PCa tissues was increased compared with benign prostate tissues. Microarray analysis demonstrated that TPX2 was positively associated with the Gleason score, tumor-node-metastasis (TNM) stage, clinicopathological stage, metastasis, overall survival and biochemical relapse-free survival. In vitro studies revealed that the high expression of TPX2 in PCa cells improved proliferative, invasive and migratory abilities, and repressed apoptosis of the PCa cells, without affecting tolerance to docetaxel. The results suggested that TPX2 serves as a tumorigenesis-promoting gene in PCa, and a potential therapeutic target for patients with PCa.

MYC Dysregulates Mitotic Spindle Function Creating a Dependency on TPX2

Tumors that overexpress the MYC oncogene frequently demonstrate aneuploidy, numerical chromosome alterations associated with highly aggressive cancers, rapid tumor evolution, and poor patient outcome. Here, we identify that MYC overexpression induces reversible defects in microtubule nucleation and mitotic spindle assembly, promoting chromosome segregation defects, micronuclei and chromosomal instability (CIN). High TPX2 expression is permissive for mitotic spindle assembly and chromosome segregation in cells with MYC overexpression; whereas TPX2 depletion blocks mitotic progression, induces cell death and prevents tumor growth. Attenuating MYC expression reverses mitotic defects, even in established tumor cell lines, implicating an ongoing role for high MYC in the persistence of CIN in tumors. Our studies implicate the MYC oncogene as a regulator of spindle assembly and identify a new MYC-TPX2 synthetic-lethal interaction that could represent a future therapeutic strategy in MYC-overexpressing cancers. Moreover, our studies suggest that blocking MYC activity can attenuate the emergence of CIN and tumor evolution.

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.

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.

TPX2 expression is associated with cell proliferation and patient outcome in esophageal squamous cell carcinoma

The molecular and genetic changes underlying esophageal squamous cell carcinoma (ESCC) tumor formation and rapid progression are poorly understood. Using high-throughput data analysis, we examined molecular changes involved in ESCC pathogenesis and investigated their clinical relevance. Five independent microarray datasets were examined for differentially expressed genes and pathways. For validation, mRNA expression in tumor and matched normal tissues from 16 ESCC cases was examined by cDNA microarray, and protein expression in 97 ESCC specimens was investigated using immunohistochemical stains. The association between clinicopathological parameters and the expression of Aurora kinase A (Aurora-A) and TPX2 was analyzed. The impact of TPX2 expression was also assessed in ESCC cancer cells. AURKA and TPX2, members of the "Role of Ran in mitotic spindle regulation" pathway, were selected for further investigation. Verification by cDNA microarray showed that both genes were overexpressed in tumor tissues, and immunohistochemical staining showed Aurora-A and TPX2 expression in 88.4 and 90.6 % of ESCC specimens, respectively. High TPX2 expression was a significant prognosticator for overall and disease-free survival in univariate analysis and remained an independent prognostic factor in multivariate analysis (HR 1.802, p = 0.037). TPX2 knockdown clones showed inhibited cellular proliferation in growth curve studies and formed fewer colonies in the clonogenic assay. Using bioinformatics resources, which were validated by microarray analysis and immunohistochemistry stains, and manipulation of TPX2 expression in ESCC cell lines, we demonstrated that TPX2 expression is associated with cell proliferation and poor prognosis among patients with resected ESCC.

Abstract 731: TPX2 overexpression is associated with tumorigenesis and patient outcome of esophageal squamous cell carcinoma

Abstract Background Esophageal squamous cell carcinoma (ESCC) is an aggressive malignancy with dismal prognosis. By microarray data analysis, we aim to identify molecular changes involved in ESCC tumorigenesis and investigate their clinical relevance. Methods Five microarray datasets were obtained from GEO database. Differentially expressed genes (DEGs) were identified using t-test with permutation. Pathway analysis was performed with LS/KS permutation statistics and Efron-Tibshirani's gene set analysis. As for the validation, we studied: (i) mRNA expression of tumor (T) and matched normal (N) tissues in 16 ESCC cases from Taipei and Taichung Veterans General Hospital by the Affymetrix HG U133A array, (ii) protein expression of target genes in 97 ESCC specimens by immunohistochemical stains (IHC), and (iii) impact of TPX2 expression on tumor cell proliferation in ESCC cell line (CE81T). Results A set of 69 DEGs (46 up and 23 down-regulated in T) was found to be overlapped among five datasets. Pathway analysis revealed eight out of 306 gene sets to have altered expression between T and N esophageal epithelium in at least three datasets. The “Role of Ran in mitotic spindle regulation” pathway, which includes AURKA and TPX2 as key regulators, was selected for further investigation. Verification by microarray analysis of 16 ESCC patients identified 12 out of 306 gene sets to have altered expression between T and N specimens. In accordance with previous results, the “Role of Ran in mitotic spindle regulation” pathway remains a significant overexpressed gene set. Both AURKA and TPX2 showed overexpression in tumor tissues (AURKA, T/N ratio = 3.13, p = 2e-07; TPX2, T/N ratio = 3.22, p = 3e-07). IHC verification showed positive AURKA and TPX2 expression in 88.4% and 90.6% of ESCC specimens, respectively. Although the expression of AURKA and TPX2 did not correlate with any clinicopathological factor, univariate survival analysis indicated high TPX2 expression as a significant prognostic factor for overall (OS) and disease-free survival (DFS) (p = 0.036 for OS and 0.038 for DFS). There was also a non-significant trend toward worse outcome in patients with high AURKA expression. In multivariate analysis, high TPX2 expression remained an independent prognostic factor (HR = 2.255, p = 0.005). To further investigate the effect of TPX2 expression, we performed MTT assay to determine cell growth of CE81T cell line after manipulating TPX2 expression level. Growth curves demonstrated that growths of vector-based TPX2 shRNA-mediated knockdown clones were inhibited compared with that of the parental and vector control groups (p &amp;lt; 0.05 on day 4 and 5). Conclusions Using bioinformatics resources, which were validated by microarray analysis/IHC in our clinical cohorts, and manipulation of TPX2 expression in CE81T cell line, we demonstrated that TPX2 overexpression is associated with tumorigenesis and patient outcome of ESCC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 731. doi:1538-7445.AM2012-731