Erratum: Exploring HMMR as a therapeutic frontier in breast cancer treatment, its interaction with various cell cycle genes, and targeting its overexpression through specific inhibitors.

[This corrects the article DOI: 10.3389/fphar.2024.1361424.].

In silico analysis unveiling potential biomarkers in gallbladder carcinogenesis.

Gallbladder cancer (GBC) is a rare but very aggressive most common digestive tract cancer with a high mortality rate due to delayed diagnosis at the advanced stage. Moreover, GBC progression shows asymptomatic characteristics making it impossible to detect at an early stage. In these circumstances, conventional therapy like surgery, chemotherapy, and radiotherapy becomes refractive. However, few studies reported some molecular markers like KRAS (Kirsten Rat Sarcoma) mutation, upregulation of HER2/neu, EGFR (Epidermal Growth Factor Receptor), and microRNAs in GBC. However, the absence of some specific early diagnostic and prognostic markers is the biggest hurdle for the therapy of GBC to date. The present study has been designed to identify some specific molecular markers for precise diagnosis, and prognosis, for successful treatment of the GBC. By In Silico a network-centric analysis of two microarray datasets; (GSE202479) and (GSE13222) from the Gene Expression Omnibus (GEO) database, shows 50 differentially expressed genes (DEGs) associated with GBC. Further network analysis revealed that 12 genes are highly interconnected based on the highest MCODE (Molecular Complex Detection) value, among all three genes; TRIP13 (Thyroid Receptor Interacting Protein), NEK2 (Never in Mitosis gene-A related Kinase 2), and TPX2 (Targeting Protein for Xklp2) having highest network interaction with transcription factors and miRNA suggesting critically associated with GBC. Further survival analysis data corroborate the association of these genes; TRIP13, NEK2, and TPX2 with GBC. Thus, TRIP13, NEK2, and TPX2 genes are significantly correlated with a greater risk of mortality, transforming them from mere biomarkers of the GBC for early detections and may emerge as prognostic markers for treatment.

Fe3O4 and Fe3O4core Aushell-based Hyperthermia Reduces Expression of Proliferation Markers Ki-67, TOP2A and TPX2 in a Human Breast Cancer Cell Line.

BACKGROUND/AIM: Hyperthermia represents an adjuvant local anticancer strategy which relies on the increase of temperature beyond the physiological level. In this study, we investigated the anticancer potential of Fe3O4 and Fe3O4core Aushell nanoparticles as hyperthermic agents in terms of cytotoxicity and studied the expression of cellular markers of proliferation (changes in mRNA levels via real-time polymerase chain reaction). MATERIALS AND METHODS: The human breast cancer cell line SK-BR-1 was incubated with either Fe3O4 or Fe3O4core Aushell nanoparticles stabilized with tryptophan, prior to hyperthermia treatment. The normal HEK293 cell line was used as a control. Toxicity was determined using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay to estimate possible toxic effects of the tested nanoparticles. After RNA extraction and cDNA synthesis, mRNA expression of three indicators of proliferation, namely marker of proliferation Ki-67, DNA topoisomerase II alpha (TOP2A) and TPX2 microtubule nucleation factor (TPX2), was investigated. RESULTS: At each concentration tested, Fe3O4core Aushell nanoparticles showed greater toxicity compared to Fe3O4, while SK-BR-3 cells were more susceptible to their cytotoxic effects compared to the HEK293 cell line. The expression of Ki-67, TOP2A and TPX2 was reduced in SK-BR-3 cells by both Fe3O4 or Fe3O4core Aushell nanoparticles compared to untreated cells, while the only observed change in HEK293 cells was the up-regulation of TOP2A. CONCLUSION: Both Fe3O4core Aushell and Fe3O4 NPs exhibit increased cytotoxicity to the cancer cell line tested (SK-BR-3) compared to HEK293 cells. The down-regulation in SK-BR-3 cells of the three proliferative markers studied, Ki-67, TOP2A and TPX2, after incubation with NPs suggests that cells that survived thermal destruction were not actively proliferating.

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.

TPX2 upregulates MMP13 to promote the progression of lipopolysaccharide-induced osteoarthritis.

Purpose: This study seeks to identify potential clinical biomarkers for osteoarthritis (OA) using bioinformatics and investigate OA mechanisms through cellular assays. Methods: Differentially Expressed Genes (DEGs) from GSE52042 (four OA samples, four control samples) were screened and analyzed with protein-protein interaction (PPI) analysis. Overlapping genes in GSE52042 and GSE206848 (seven OA samples, and seven control samples) were identified and evaluated using Gene Set Enrichment Analysis (GSEA) and clinical diagnostic value analysis to determine the hub gene. Finally, whether and how the hub gene impacts LPS-induced OA progression was explored by in vitro experiments, including Western blotting (WB), co-immunoprecipitation (Co-IP), flow cytometry, etc. Result: Bioinformatics analysis of DEGs (142 up-regulated and 171 down-regulated) in GSE52042 identified two overlapping genes (U2AF2, TPX2) that exhibit significant clinical diagnostic value. These genes are up-regulated in OA samples from both GSE52042 and GSE206848 datasets. Notably, TPX2, which AUC = 0.873 was identified as the hub gene. In vitro experiments have demonstrated that silencing TPX2 can alleviate damage to chondrocytes induced by lipopolysaccharide (LPS). Furthermore, there is a protein interaction between TPX2 and MMP13 in OA. Excessive MMP13 can attenuate the effects of TPX2 knockdown on LPS-induced changes in OA protein expression, cell growth, and apoptosis. Conclusion: In conclusion, our findings shed light on the molecular mechanisms of OA and suggested TPX2 as a potential therapeutic target. TPX2 could promote the progression of LPS-induced OA by up-regulating the expression of MMP13, which provides some implications for clinical research.

Integrative analysis based on the cell cycle-related genes identifies TPX2 as a novel prognostic biomarker associated with tumor immunity in breast cancer.

BACKGROUND: This study aims to identify the essential cell cycle-related genes associated with prognosis in breast cancer (BRCA), and to verify the relationship between the central gene and immune infiltration, so as to provide detailed and comprehensive information for the treatment of BRCA. MATERIALS AND METHODS: Gene expression profiles (GSE10780, GSE21422, GSE61304) and the Cancer Genome Atlas (TCGA) BRCA data were used to identify differentially expressed genes (DEGs) and further functional enrichment analysis. STRING and Cytoscape were employed for the protein-protein interaction (PPI) network construction. TPX2 was viewed as the crucial prognostic gene by the Survival and Cox analysis. Furthermore, the connection between TPX2 expression and immune infiltrating cells and immune checkpoints in BRCA was also performed by the TIMER online database and R software. RESULTS: A total of 18 cell cycle-related DEGs were identified in this study. Subsequently, an intersection analysis based on TCGA-BRCA prognostic genes and the above DEGs identified three genes (TPX2, UBE2C, CCNE2) as crucial prognostic candidate biomarkers. Moreover, we also demonstrated that TPX2 is closely associated with immune infiltration in BRCA and a positive relation between TPX2 and PD-L1 expression was firstly detected. CONCLUSIONS: These results revealed that TPX2 is a potential prognostic biomarker and closely correlated with immune infiltration in BRCA, which could provide powerful and efficient strategies for breast cancer immunotherapy.

Exploring HMMR as a therapeutic frontier in breast cancer treatment, its interaction with various cell cycle genes, and targeting its overexpression through specific inhibitors.

Among women, breast carcinoma is one of the most complex cancers, with one of the highest death rates worldwide. There have been significant improvements in treatment methods, but its early detection still remains an issue to be resolved. This study explores the multifaceted function of hyaluronan-mediated motility receptor (HMMR) in breast cancer progression. HMMR's association with key cell cycle regulators (AURKA, TPX2, and CDK1) underscores its pivotal role in cancer initiation and advancement. HMMR's involvement in microtubule assembly and cellular interactions, both extracellularly and intracellularly, provides critical insights into its contribution to cancer cell processes. Elevated HMMR expression triggered by inflammatory signals correlates with unfavorable prognosis in breast cancer and various other malignancies. Therefore, recognizing HMMR as a promising therapeutic target, the study validates the overexpression of HMMR in breast cancer and various pan cancers and its correlation with certain proteins such as AURKA, TPX2, and CDK1 through online databases. Furthermore, the pathways associated with HMMR were explored using pathway enrichment analysis, such as Gene Ontology, offering a foundation for the development of effective strategies in breast cancer treatment. The study further highlights compounds capable of inhibiting certain pathways, which, in turn, would inhibit the upregulation of HMMR in breast cancer. The results were further validated via MD simulations in addition to molecular docking to explore protein-protein/ligand interaction. Consequently, these findings imply that HMMR could play a pivotal role as a crucial oncogenic regulator, highlighting its potential as a promising target for the therapeutic intervention of breast carcinoma.

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.

INTRODUCTION: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

AurkA/TPX2 co-overexpression in nontransformed cells promotes genome instability through induction of chromosome mis-segregation and attenuation of the p53 signalling pathway.

The Aurora-A kinase (AurkA) and its major regulator TPX2 (Targeting Protein for Xklp2) are key mitotic players frequently co-overexpressed in human cancers, and the link between deregulation of the AurkA/TPX2 complex and tumourigenesis is actively investigated. Chromosomal instability, one of the hallmarks of cancer related to the development of intra-tumour heterogeneity, metastasis and chemo-resistance, has been frequently associated with TPX2-overexpressing tumours. In this study we aimed to investigate the actual contribution to chromosomal instability of deregulating the AurkA/TPX2 complex, by overexpressing it in nontransformed hTERT RPE-1 cells. Our results show that overexpression of both AurkA and TPX2 results in increased AurkA activation and severe mitotic defects, compared to AurkA overexpression alone. We also show that AurkA/TPX2 co-overexpression yields increased aneuploidy in daughter cells and the generation of micronucleated cells. Interestingly, the p53/p21 axis response is impaired in AurkA/TPX2 overexpressing cells subjected to different stimuli; consistently, cells acquire increased ability to proliferate after independent induction of mitotic errors, i.e. following nocodazole treatment. Based on our observation that increased levels of the AurkA/TPX2 complex affect chromosome segregation fidelity and interfere with the activation of a pivotal surveillance mechanism in response to altered cell division, we propose that co-overexpression of AurkA and TPX2 per se represents a condition promoting the generation of a genetically unstable context in nontransformed human cells.

Discovery of N-benzylbenzamide-based allosteric inhibitors of Aurora kinase A.

Aurora kinases (AurkA/B/C) regulate the assembly of bipolar mitotic spindles and the fidelity of chromosome segregation during mitosis, and are attractive therapeutic targets for cancers. Numerous ATP-competitive AurkA inhibitors have been developed as potential anti-cancer agents. Recently, a few allosteric inhibitors have been reported that bind to the allosteric Y-pocket within AurkA kinase domain and disrupt the interaction between AurkA and its activator TPX2. Herein we report a novel allosteric AurkA inhibitor (6h) of N-benzylbenzamide backbone. Compound 6h suppressed the both catalytic activity and non-catalytic functions of AurkA. The inhibitory activity of 6h against AurkA (IC50 = 6.50 µM) was comparable to that of the most potent allosteric AurkA inhibitor AurkinA. Docking analysis against the Y-pocket revealed important pharmacophores and interactions that were coherent with structure-activity relationship. In addition, 6h suppressed DNA replication in G1-S phase, which is a feature of allosteric inhibition of AurA. Our current study may provide a useful insight in designing potent allosteric AurkA inhibitors.

TPX2 overexpression promotes sensitivity to dasatinib in breast cancer by activating YAP transcriptional signaling.

Chromosomal instability (CIN) is a hallmark of cancer aggressiveness, providing genetic plasticity and tumor heterogeneity that allows the tumor to evolve and adapt to stress conditions. CIN is considered a cancer therapeutic biomarker because healthy cells do not exhibit CIN. Despite recent efforts to identify therapeutic strategies related to CIN, the results obtained have been very limited. CIN is characterized by a genetic signature where a collection of genes, mostly mitotic regulators, are overexpressed in CIN-positive tumors, providing aggressiveness and poor prognosis. We attempted to identify new therapeutic strategies related to CIN genes by performing a drug screen, using cells that individually express CIN-associated genes in an inducible manner. We find that the overexpression of targeting protein for Xklp2 (TPX2) enhances sensitivity to the proto-oncogene c-Src (SRC) inhibitor dasatinib due to activation of the Yes-associated protein 1 (YAP) pathway. Furthermore, using breast cancer data from The Cancer Genome Atlas (TCGA) and a cohort of cancer-derived patient samples, we find that both TPX2 overexpression and YAP activation are present in a significant percentage of cancer tumor samples and are associated with poor prognosis; therefore, they are putative biomarkers for selection for dasatinib therapy.

Integrative analysis confirms TPX2 as a novel biomarker for clinical implication, tumor microenvironment, and immunotherapy response across human solid tumors.

Targeting Protein for Xenopus Kinesin Like Protein 2 (TPX2) serves as a microtubule associated protein for the regulation of spindle assembly and tumorigenesis. We aim to investigate the prognostic and immunological role of TPX2 in pan-cancer. TCGA database, Tumor Immune Single-cell Hub (TISCH), and Human Protein Atlas (HPA) were retrieved to evaluate the expression pattern of TPX2 as well as its diagnostic and prognostic value in solid tumors. Genomic alterations of TPX2 were assessed with cBioPortal database. In vitro experiments in lung adenocarcinoma (LUAD) were performed to confirm the potential role of TPX2. Overexpression of TPX2 was found in 22 types of cancers, and was positively related with copy number variations (CNV) and negative with methylation. Up-regulated TPX2 could predict worse outcomes in the majority of cancers. Single-cell analysis revealed that TPX2 was mainly distributed in malignant cells (especially in glioma) and proliferating T cells. Genomic alteration of TPX2 was common in different types of tumors, while with prognostic value in two types of cancers. Additionally, significant correlations were found between TPX2 expression and tumor microenvironment (including stromal cells and immune cells) as well as immune related genes across cancer types. Drug sensitivity analysis revealed that TPX2 could predict response to chemotherapy and immunotherapy. Functional analyses demonstrated close relationship of TPX2 with immune function and malignant phenotypes. Finally, it was confirmed that knockdown of TPX2 could reduce proliferation and migration ability of LUAD cells. In summary, TPX2 could serve as a diagnostic and prognostic biomarker and a potential immunotherapy marker.

TPX2 influences the regulation of macrophage polarization via the NF-κB pathway in lung adenocarcinoma.

BACKGROUND: Lung adenocarcinoma (LUAD) is the most prevalent subtype of lung cancer. Xklp2 targeting protein (TPX2), a crucial oncogene exhibits high expression levels in various cancers including LUAD, may serve as a potential target for clinical intervention. Additionally, the growth of lung cancer is significantly influenced by the tumor microenvironment (TME). However, there have been no reports on experiments investigating TPX2 in tumor-infiltrating immune cells (TIICs) in LUAD. Therefore, we verified the effect of TPX2 on macrophage polarization both in vitro and in vivo. METHODS: We silenced TPX2 the gene in A549 cells and collected supernatants for macrophage culture. We then used flow cytometry and Western blot analysis to assess macrophage polarization. Additionally, we verified the expression of macrophage colony-stimulating factor (M-CSF), and CD163 by immunohistochemistry (IHC) in tissue specimens from LUAD patients. Finally, pathways related to TPX2's regulatory function in macrophage polarization were analyzed through whole genome sequencing, Western blotting, and immunofluorescence (IF). RESULTS: Silencing TPX2 can affect the ratio of CD80+ M1/CD163+ M2 and reduce the polarization of M0 macrophages to CD163+ M2 macrophages mainly by inhibiting the expression of M-CSF. In human LUAD tissues, the expression levels of TPX2, M-CSF and CD163 increased with the degree of differentiation. Silencing TPX2 inhibits the NF-κB signaling pathway, thereby reducing the expression of M-CSF, and affecting macrophage polarization. CONCLUSION: Silencing TPX2 can inhibit the expression of M-CSF by blocking the NF-κB signal, thereby reducing CD163+ M2 macrophage polarization. The TPX2/NF-κB/M-CSF signaling axis may be involved in regulating macrophage polarization.

[miR-218-5p Targeting TPX2 Regulates p53 Pathway and Inhibits Malignant Progression of Lung Adenocarcinoma].

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: miR-218-5p targets and inhibits TPX2 expression and exerts an inhibitory effect on the malignant progression of LUAD cells via p53.

Therapeutic targeting of the TPX2/TTK network in colorectal cancer.

BACKGROUND: While the increased screening, changes in lifestyle, and recent advances in treatment regimen have decreased colorectal cancer (CRC) mortality, metastatic disease and recurrence remains a major clinical challenge. In the era of precision medicine, the identification of actionable novel therapeutic targets could ultimately offer an alternative treatment strategy for CRC. METHODS: RNA-Seq was conducted using the illumina platform, while bioinformatics analyses were conducted using CLC genomics workbench and iDEP.951. Colony forming unit, flow cytometry, and fluorescent microscopy were used to assess cell proliferation, cell cycle distribution, and cell death, respectively. The growth potential of CRC cells under 3-dimensional (3D) conditions was assessed using Matrigel. STRING database (v11.5) and Ingenuity Pathway Analysis (IPA) tool were used for network and pathway analyses. CRISPR-Cas9 perturbational effects database was used to identify potential therapeutic targets for CRC, through integration with gene-drug interaction database. Structural modeling and molecular docking were used to assess the interaction between candidate drugs and their targets. RESULTS: In the current study, we investigated the therapeutic potential of targeting TPX2, TTK, DDX39A, and LRP8, commonly upregulated genes in CRC identified through differential expression analysis in CRC and adjacent non-cancerous tissue. Targeted depletion of TPX2 and TTK impaired CRC proliferation, cell cycle progression, and organoid formation under 3D culture conditions, while suppression of DDX39A and LRP8 had modest effects on CRC colony formation. Differential expression analysis and bioinformatics on TPX2 and TTK-deficient cells identified cell cycle regulation as the hallmark associated with loss of TPX2 and TTK. Elevated expression of TPX2 and TTK correlated with an oncogenic state in tumor tissue from patients with colon adenocarcinoma, thus corroborating an oncogenic role for the TPX2/TTK network in the pathogenesis of CRC. Gene set enrichment and pathway analysis of TPX2high/TTKhigh CRC identified numerous additional gene targets as integral components of the TPX2/TTK network. Integration of TPX2/TTK enriched network with CRISPR-Cas9 functional screen data identified numerous novel dependencies for CRC. Additionally, gene-drug interaction analysis identified several druggable gene targets enriched in the TPX2/TTK network, including AURKA, TOP2A, CDK1, BIRC5, and many others. CONCLUSIONS: Our data has implicated an essential role for TPX2 and TTK in CRC pathogenesis and identified numerous potential therapeutic targets and their drug interactions, suggesting their potential clinical use as a novel therapeutic strategy for patients with CRC. Video Abstract.

Microtubule nucleation for spindle assembly: one molecule at a time.

The cell orchestrates the dance of chromosome segregation with remarkable speed and fidelity. The mitotic spindle is built from scratch after interphase through microtubule (MT) nucleation, which is dependent on the γ-tubulin ring complex (γ-TuRC), the universal MT template. Although several MT nucleation pathways build the spindle framework, the question of when and how γ-TuRC is targeted to these nucleation sites in the spindle and subsequently activated remains an active area of investigation. Recent advances facilitated the discovery of new MT nucleation effectors and their mechanisms of action. In this review, we illuminate each spindle assembly pathway and subsequently consider how the pathways are merged to build a spindle.

HURP localization in metaphase is the result of a multi-step process requiring its phosphorylation at Ser627 residue.

Faithful chromosome segregation during cell division requires accurate mitotic spindle formation. As mitosis occurs rapidly within the cell cycle, the proteins involved in mitotic spindle assembly undergo rapid changes, including their interactions with other proteins. The proper localization of the HURP protein on the kinetochore fibers, in close proximity to chromosomes, is crucial for ensuring accurate congression and segregation of chromosomes. In this study, we employ photoactivation and FRAP experiments to investigate the impact of alterations in microtubule flux and phosphorylation of HURP at the Ser627 residue on its dynamics. Furthermore, through immunoprecipitations assays, we demonstrate the interactions of HURP with various proteins, such as TPX2, Aurora A, Eg5, Dynein, Kif5B, and Importin ß, in mammalian cells during mitosis. We also find that phosphorylation of HURP at Ser627 regulates its interaction with these partners during mitosis. Our findings suggest that HURP participates in at least two distinct complexes during metaphase to ensure its proper localization in close proximity to chromosomes, thereby promoting the bundling and stabilization of kinetochore fibers.

An Analysis Regarding the Association Between the Nuclear Pore Complex (NPC) and Hepatocellular Carcinoma (HCC).

Background: The nuclear pore complex (NPC) is the main mediator of nuclear and cytoplasmic communication, and delaying or blocking nuclear RNA export and protein shuttling can inhibit cell proliferation and induce apoptosis. Although NPC is a research hotspot in structural biology, relevant studies in hepatocellular carcinoma are scarce, especially in terms of translation into clinical practice. Methods: This study used a bioinformatics approach combining validation experiments to investigate the biological mechanisms that may be related with NPC. A series of experiments performed to explore the function of the Targeting protein for Xenopus kinesin-like protein 2 (TPX2) in HCC. Results: Patients with HCC can be divided into two NPC clusters. Patients with high NPC levels (C1) had a shorter survival time than those with low NPC levels (C2) and are characterised by high levels of proliferative signals. We demonstrated that TPX2 regulates HCC growth and inhibits apoptosis in an NPC-dependent manner and contributes to the maintenance of HCC stemness. We developed the NPCScore to predict the prognosis and degree of differentiation in HCC patients. Conclusion: NPC plays an important role in the malignant proliferation of HCC. Assessing NPC expression patterns could help enhance our understanding of tumor cell proliferation and could guide more effective chemotherapeutic strategies.

Transmission of Exosomal TPX2 Promotes Metastasis and Resistance of NSCLC Cells to Docetaxel.

Background: Lung cancer, most of which is non-small cell lung cancer (NSCLC), is the most common tumor in the world, and drug resistance, as a major problem in clinical treatment, has attracted extensive attention. However, the role and mechanism of Targeting protein for Xenopus kinesin-like protein 2 (TPX2), which is highly expressed in NSCLC, is still unclear. Methods: Bioinformatics analysis was used to analyze the relationship between TPX2 and the clinicopathological features of NSCLC. Stable TPX2 overexpression cell lines with were constructed by lentivirus infection, and the effect of TPX2 on proliferation, migration, invasion and chemoresistance to docetaxel was characterized by the CCK8, wound healing, transwell, colony formation assay and FACS. An in vivo lung homing mouse model was used to further confirmed the role of TPX2 on metastasis. Exosomes were extracted by differential centrifugation from the culture supernatant, and their functions were investigated by co-culture with tumor cells. Gene expression was detected via Western blot and real time PCR (RT-qPCR). Results: Overexpression of TPX2 was related to the poor prognosis of NSCLC. Promoted migration, invasion and metastasis, and reduced the sensitivity of NSCLC cells to docetaxel. The abundance of TPX2 can be packaged in vesicles and transported to other cells. In addition, overexpression of TPX2 induced the accumulation of ß-catenin and C-myc. Conclusion: Our findings indicated that intercellular transfer of exosomal TPX2 triggered metastasis and resistance against to docetaxel in lung cancer cells, through activating downstream WNT/ß-catenin signaling pathway.

Bioinformatics and experimental validation of an AURKA/TPX2 axis as a potential target in esophageal squamous cell carcinoma.

Aurora kinase A (AURKA), a serine/threonine kinase that regulates mitotic processes, has garnered significant interest given its association with the development of several types of cancer. In the present study, it was shown that AURKA expression was significantly upregulated in esophageal squamous cell carcinoma (ESCC) and could serve as a diagnostic and prognostic indicator based on data obtained from The Cancer Genome Atlas (TCGA) and immunohistochemical analysis. In addition, AURKA was functionally associated with ESCC cell proliferation and colony formation in vitro and knockdown of AURKA inhibited ESCC tumor growth in vivo. Both bioinformatics analysis and pull­down assays demonstrated that TPX2 interacted with AURKA, and their expression was correlated. AURKA cooperated with TPX2 to regulate ESCC progression via the PI3K/Akt pathway. Furthermore, AURKA or TPX2 expression levels were negatively associated with the infiltration of cytotoxic cells, CD8+ T cells and mast cells, but positively associated with Th2 cells. The present study provided a relatively comprehensive understanding of the oncogenic roles of AURKA in ESCC based on data obtained from TCGA combined with experimental analysis.