NUSAP1 regulates mouse oocyte meiotic maturation.

The correct assembly of the spindle apparatus directly regulates the precise separation of chromosomes in mouse oocytes, which is crucial for obtaining high-quality oocytes capable of successful fertilization. The localization, assembly, migration, and disassembly of the spindle are regulated by a series of spindle-associated proteins, which exhibit unique expression level variations and specific localization in oocytes. Proteomic analysis revealed that among many representative spindle-associated proteins, the expression level of nucleolar and spindle-associated protein 1 (NUSAP1) significantly increased after meiotic resumption, with a magnitude of change higher than that of other proteins. However, the role of NUSAP1 during oocyte meiosis maturation has not been reported. Here, we report that NUSAP1 is distributed within the cell nucleus during the germinal vesicle (GV) oocytes with non-surrounded nucleolus stage and is not enriched in the nucleus during the GV-surrounded nucleolus stage. Interestingly, NUSAP1 forms distinct granular aggregates near the spindle poles during the prophase of the first meiotic division (Pro-MI), metaphase I, and anaphase I/telophase I stages. Nusap1 depletion leads to chromosome misalignment, increased aneuploidy, and abnormal spindle assembly, particularly a decrease in spindle pole width. Correspondingly, RNA-seq analysis revealed significant suppression of the "establishment of spindle orientation" signaling pathway. Additionally, the attenuation of F-actin in NUSAP1-deficient oocytes may affect the asymmetric division process. Gene ontology analysis of NUSAP1 interactomes, identified through mass spectrometry here, revealed significant enrichment for RNA binding. As an RNA-binding protein, NUSAP1 is likely involved in the regulation of messenger RNA homeostasis by influencing the dynamics of processing (P)-body components. Overall, our results demonstrate the critical importance of precise regulation of NUSAP1 expression levels and protein localization for maintaining mouse oocyte meiosis.

A recurrent de novo variant in NUSAP1 escapes nonsense-mediated decay and leads to microcephaly, epilepsy, and developmental delay.

NUSAP1 encodes a cell cycle-dependent protein with key roles in mitotic progression, spindle formation, and microtubule stability. Both over- and under-expression of NUSAP1 lead to dysregulation of mitosis and impaired cell proliferation. Through exome sequencing and Matchmaker Exchange, we identified two unrelated individuals with the same recurrent, de novo heterozygous variant (NM_016359.5 c.1209C > A; p.(Tyr403Ter)) in NUSAP1. Both individuals had microcephaly, severe developmental delay, brain abnormalities, and seizures. The gene is predicted to be tolerant of heterozygous loss-of-function mutations, and we show that the mutant transcript escapes nonsense mediated decay, suggesting that the mechanism is likely dominant-negative or toxic gain of function. Single-cell RNA-sequencing of an affected individual's post-mortem brain tissue indicated that the NUSAP1 mutant brain contains all main cell lineages, and that the microcephaly could not be attributed to loss of a specific cell type. We hypothesize that pathogenic variants in NUSAP1 lead to microcephaly possibly by an underlying defect in neural progenitor cells.

Transcription Factor E2F8 Promotes Cisplatin Resistance in Hepatocellular Carcinoma by Regulating DNA Damage via NUSAP1.

DNA damage repair has been the key mechanism of cisplatin resistance in hepatocellular carcinoma (HCC). The present study elucidated the molecular mechanism by which nucleolar and spindle-associated protein 1 (NUSAP1) influenced cisplatin tolerance in HCC by regulating DNA damage. First, high mRNA expression of E2F8 and NUSAP1 in HCC was detected by real-time quantitative PCR in cells and tumor tissue. The interaction between E2F8 and NUSAP1 was confirmed by chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays that E2F8 bound to the promoter region of NUSAP1 and regulated its transcriptional activity. The effects of the E2F8/NUSAP1 axis on cell viability, cell cycle, DNA damage protein γ-H2AX, and cisplatin resistance were investigated by CCK-8, flow cytometry, comet detection, and western blot. The results showed that NUSAP1 knockdown blocked the cell cycle in G0/G1 phase, promoted cisplatin-induced DNA damage, and enhanced cisplatin sensitivity in HCC. Overexpressed E2F8 promoted cell cycle arrest by silencing NUSAP1 in HCC, and promoting DNA damage as well as cisplatin sensitivity. In conclusion, our results suggested that E2F8 enhanced the chemoresistance of HCC cells to cisplatin by activating NUSAP1 to inhibit DNA damage, which provides a basis for describing new therapeutic targets that effectively exacerbate DNA damage and improve the chemical sensitivity of HCC to cisplatin.

NUSAP1 Binds ILF2 to Modulate R-Loop Accumulation and DNA Damage in Prostate Cancer.

Increased expression of NUSAP1 has been identified as a robust prognostic biomarker in prostate cancer and other malignancies. We have previously shown that NUSAP1 is positively regulated by E2F1 and promotes cancer invasion and metastasis. To further understand the biological function of NUSAP1, we used affinity purification and mass spectrometry proteomic analysis to identify NUSAP1 interactors. We identified 85 unique proteins in the NUSAP1 interactome, including ILF2, DHX9, and other RNA-binding proteins. Using proteomic approaches, we uncovered a function for NUSAP1 in maintaining R-loops and in DNA damage response through its interaction with ILF2. Co-immunoprecipitation and colocalization using confocal microscopy verified the interactions of NUSAP1 with ILF2 and DHX9, and RNA/DNA hybrids. We showed that the microtubule and charged helical domains of NUSAP1 were necessary for the protein-protein interactions. Depletion of ILF2 alone further increased camptothecin-induced R-loop accumulation and DNA damage, and NUSAP1 depletion abolished this effect. In human prostate adenocarcinoma, NUSAP1 and ILF2 mRNA expression levels are positively correlated, elevated, and associated with poor clinical outcomes. Our study identifies a novel role for NUSAP1 in regulating R-loop formation and accumulation in response to DNA damage through its interactions with ILF2 and hence provides a potential therapeutic target.

Identification and clinical validation of NUSAP1 as a novel prognostic biomarker in ovarian cancer.

BACKGROUND: Nucleolar and spindle-associated protein 1 (NUSAP1) was shown to be involved in cell cycle regulation in cancer. However, its prognostic value and underlying mechanism in ovarian cancer remain unclear. METHODS: Oncomine, TCGA, CCLE, and UALCAN databases were used to analyze the expression level of NUSAP1 in ovarian cancer. The Kaplan-Meier plotter database was used to evaluate its prognostic value. The results from these analyses were further validated using immunohistochemical assay. The potential molecular mechanism of NUSAP1 in ovarian cancer was assessed with respect to homologous recombination repair, mismatch repair, and immunology using different databases. RESULTS: Database analyses and experimental results demonstrated that NUSAP1 was highly expressed in ovarian cancer, its levels being correlated with the FIGO stage. High NUSAP1 expression was an independent risk factor affecting the prognosis of patients with epithelial ovarian cancer. Moreover, NUSAP1 was associated with cell cycle, DNA replication, homologous recombination, and p53 signaling pathway. A positive correlation was identified between the expression of NUSAP1 and BRCA1/2 in ovarian cancer. In addition, NUSAP1 was associated with the expression of DNA mismatch repair genes and immune cell infiltration. CONCLUSIONS: NUSAP1 may be a valuable prognostic marker, as well as a novel biomarker for evaluating the response to immunotherapy of patients with ovarian cancer.

Evaluate the diagnostic and prognostic value of NUSAP1 in papillary thyroid carcinoma and identify the relationship with genes, proteins, and immune factors.

BACKGROUND: Nucleolar spindle-associated protein 1 (NUSAP1) is reported to be a useful diagnostic and prognostic marker for a variety of cancers, but relevant studies are lacking in papillary thyroid carcinoma (PTC). METHODS: The relationship between NUSAP1 expression and the overall survival (OS) of pan-cancer was examined by GEPIA and KMplot. We explored the relationship between NUSAP1 and clinical PTC data based on the THCA dataset of TCGA and the GEO dataset of NCBI; GO, KEGG analysis, and ceRNA networks were performed on co-expressed genes through LinkedOmics and Starbase. We assessed the relevance between NUSAP1 and the tumor microenvironment using ESTIMATE, correlations between NUSAP1 and immune cells with TIMER, the relationship between NUSAP1 and immunotherapy by TCIA, and small-molecule drugs targeting NUSAP1 that can be discovered using the CMap database. RESULTS: Higher expression of NUSAP1 in pan-cancer tissues was correlated with shorter OS. NUSAP1 was also significantly expressed in PTC tissues and was an independent prognostic risk factor. Compared to the NUSAP1 low expression group, the NUSAP1 high expression group was more likely to also have lymph node metastasis, pathological PTC type, shorter progression-free survival (PFS), and higher scores for immune checkpoint inhibitor treatment. The genes associated with NUSAP1 were mostly involved in the cell cycle, immune-related pathways, and AITD. Ten lncRNAs (GAS5, SNHG7, UCA1, SNHG1, HCP5, DLEU2, HOTAIR, TP53TG1, SNHG12, C9orf106), eleven miRNAs (hsa-miR-10a-5p, hsa-miR-10b-5p, hsa-miR-18a-5p, hsa-miR-18b-5p, hsa-miR-128-3p, hsa-miR-214-3p, hsa-miR-219a-2-3p, hsa-miR-339-5p, hsa-miR-494-3p, hsa-miR-545-3p, hsa-miR-769-5p), and one mRNA (NUSAP1) were constructed. NUSAP1 participated in the formation of the tumor microenvironment. CMap predicted the 10 most important small molecules about NUSAP1. CONCLUSIONS: In PTC, NUSAP1 shows good diagnostic value and prognostic value; NUSAP1 impacts the cell cycle, immune-related pathways, and AITD and has a complex effect on the tumor microenvironment in PTC.

[miR-758-3p inhibits the proliferation and invasion of non-small cell lung cancer cells by targeting NUSAP1].

Objective: To investigate the biological function of miR-758-3p and the underlying mechanism in non-small cell lung cancer (NSCLC). Methods: miR-758-3p mimics was transfected to A549 NSCLC cells, miRNA control was used as a negative control, cells transfected with nucleolar and spindle associated protein 1 (NUSAP1)-overexpression vector indicated as NUSAP1 group, cells co-transfected with miR-758-3p mimics and NUSAP1-overexpression vector indicated as miR-758-3p mimics+ NUSAP1 group. The effects of miR-758-3p on the proliferation, migration and invasion abilities of A549 cells were detected by cell counting kit-8 (CCK-8) and Transwell assays, respectively. Bioinformatics and dual luciferase reporter assay were used to predict and verify the target gene of miR-758-3p. Results: The expressions of miR-758-3p and NUSAP1 in A549 cells were significantly up-regulated at 24 hours after transfection with miR-758-3p mimics (P<0.05). Compared with the miRNA control group (1.15±0.06), the OD value of miR-758-3p mimic group (0.78±0.06) was significantly decreased at 72 hours after transfection (P<0.05). The number of migrated cells of miR-758-3p mimic group (119.04±11.49) was significantly lower than that of the control group (271.38±19.05) (P<0.05). The number of invaded cells of miR-758-3p mimic group (71.33±5.36) was significantly lower than the control group (164.30±8.11) (P<0.05). The result of dual-luciferase reporter assay showed that NUSAP1 was a direct target of miR-758-3p. Moreover, up-regulation of NUSAP1 abolished the inhibitory effects of miR-758-3p on the proliferation, migration and invasion abilities of A549 cells. Conclusion: miR-758-3p inhibits the proliferation, migration and invasion of NSCLC cells by targeting NUSAP1.

NUSAP1 knockdown inhibits cell growth and metastasis of non-small-cell lung cancer through regulating BTG2/PI3K/Akt signaling.

Non-small-cell lung cancer (NSCLC) is the most common malignancy along with high mortality rate worldwide. Recently, nucleolar and spindle-associated protein 1 (NUSAP1) has been reported to be involved in the malignant progression of several cancers. However, in NSCLC, the biological function of NUSAP1 and its molecular mechanism have not been reported. Here, our findings indicated that the NUSAP1 messenger RNA expression level was remarkably upregulated in NSCLC tissues compared with that of adjacent normal tissues. We also found that NUSAP1 gene expression was notably upregulated in NSCLC cell lines (A549, 95-D, H358, and H1299) compared with that of normal human bronchial epithelial cell line (16HBE). Subsequently, the biological function of NUSAP1 was investigated in A549 and H358 cells transfected with NUSAP1 small interfering RNA (siRNA), respectively. Results showed that NUSAP1 knockdown inhibited NSCLC cell proliferation, and promoted cell apoptosis. Furthermore, the number of cell migration and invasion was significantly suppressed by NUSAP1 knockdown. In addition, our results indicated that NUSAP1 knockdown increased the gene expression of B-cell translocation gene 2 (BTG2), but decreased the expression levels of phosphoinositide 3-kinase (PI3K) and phosphorylated serine/threonine kinase (p-AKT). BTG2 siRNA partly abrogates the effect of NUSAP1 knockdown on BTG2 gene expression. Fumonisin B1 (FB1), a AKT activator, reversed the effect of NUSAP1 knockdown on the biological function in NSCLC. Taken together, NUSAP1 knockdown promotes NSCLC cell apoptosis, and inhibits cell proliferation, cell migration, and invasion, which is associated with regulating BTG2/PI3K/Akt signal pathway. Our findings suggest that NUSAP1 is a promising molecular target for NSCLC treatment.

The role of nucleolar spindle-associated protein 1 in human ovarian cancer.

Ovarian cancer (OC) is one of the deadliest malignancies of the female reproductive system. The present study focused on the role of Nucleolar spindle-associated protein 1 (NuSAP1) in OC. Relative expression of NuSAP1 was detected in OC tissues as well as cells. After knocking down NuSAP1 with lentivirus-mediated shRNA and verifying the knockdown efficiency via quantitative real-time polymerase chain reaction and Western blot assays, the cell proliferation, apoptosis, and cell cycle were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, colony formation, and flow cytometry, respectively. Transwell assay was conducted to detect the migration and invasion of OC cells. It was showed that NuSAP1 was abundantly expressed in OC tissues and cell lines. After knocking down NuSAP1 in OC cells, in addition to significantly inhibiting proliferation and colony forming ability, it also promotes apoptosis and affects cell cycle distribution. Moreover, cells in the shNuSAP1 group showed significantly suppressed migration and invasion ability compared with that in the shCtrl group. In conclusion, NuSAP1 may act as an oncogenic factor in OC and therefore might serve as an indicator for prognosis and therapeutic target for OC treatment.

Nucleolar and spindle-associated protein 1 accelerates cellular proliferation and invasion in nasopharyngeal carcinoma by potentiating Wnt/ß-catenin signaling via modulation of GSK-3ß.

Nucleolar and spindle-associated protein 1 (NUSAP1) is a pivotal tumor-related protein that has been implicated in the progression of broad spectrum of tumors. However, no detailed study of the role of NUSAP1 in nasopharyngeal carcinoma (NPC) has been reported. The aim of this work is to enhance our understanding of NUSAP1 in the progression of NPC. By analyzing data available within the Oncomine database, we found that NUSAP1 expression was elevated in NPC relative to normal tissues. Further, we showed that NUSAP1 expression in clinical specimens of NPC and several NPC cell lines was elevated. Down-regulation of NUSAP1 by gene silencing markedly depleted the capacity of NPC cells to proliferate and invade. Contrastingly, overexpression of NUSAP1 potentiated the proliferative and invasive abilities of NPC cells. Further mechanistic research revealed that NUSAP1 knockdown decreased levels of Wnt/ß-catenin signaling in NPC cells via a mechanism associated with downregulation of glycogen synthase kinase-3ß (GSK-3ß) phosphorylation. However, suppression of GSK-3ß markedly abolished the inhibitory effect of NUSAP1 knockdown on Wnt/ß-catenin signaling. Further, inhibition of Wnt/ß-catenin signaling partially reversed NUSAP1-mediated tumor growth in NPC cells. In addition, NUSAP1 knockdown restrained tumorigenesis of NPC in vivo, and was associated with down-regulation of Wnt/ß-catenin signaling. In conclusion, these findings demonstrate that NUSAP1 is capable of accelerating proliferation and invasion in NPC cells by potentiating Wnt/ß-catenin signaling. Our study unveils a potential role of NUSAP1 in promoting NPC tumors and suggests that the protein is an attractive antitumor target for NPC treatment.

Downregulation of NUSAP1 suppresses cell proliferation, migration, and invasion via inhibiting mTORC1 signalling pathway in gastric cancer.

Gastric cancer (GC) is one of the most common causes of cancer-related death worldwide, and outstanding biomarkers for therapeutic targets or predicting GC survival are still lacking. Increasing evidence indicated that nucleolar and spindle associated protein 1 (NUSAP1) involved in regulating the progression of various cancers; however, its specific role in GC remained unclear. In this study, we found that NUSAP1 was upregulated in the GC tissues and cell lines via analysing data from The Cancer Genome Atlas (TCGA), gene expression omnibus (GEO), qRT-PCR, and western blot assays. Patients with high NUSAP1 expression levels showed shorter free-progression survival (FPS), larger tumour size, and higher lymphatic metastasis rate compared with those with low NUSAP1 expression. Further functional experiments revealed knockdown of NUSAP1 could inhibit the growth, migration, and invasion of GC cells in vitro and vivo. Additionally, silencing NUSAP1 induced G0/G1 phase arrest, apoptosis, and suppressed the epithelial-mesenchymal transition (EMT) process. Finally, we performed gene set enrichment analysis (GSEA) and observed NUSAP1 was positive with mTORC1 signalling pathway, which was verified by the subsequent immunoblotting. In conclusion, our findings suggested that NUSAP1 contributed to GC progression and may act as a potential therapeutic target for GC. SIGNIFICANCE OF THE STUDY: Our results firstly illuminated that NUSAP1 expression was significantly upregulated in GC tissues and predicted poor FPS. Silencing it could attenuate GC progression via inhibiting mTORC1 signalling pathway. Hence, NUSAP1 may act as a promising therapy target for GC.

NUSAP1 gene silencing inhibits cell proliferation, migration and invasion through inhibiting DNMT1 gene expression in human colorectal cancer.

Colorectal cancer (CRC) is one of the most common cause of cancer-related death in both female and male patients, with a high capacity for tumor migration and invasion. Recently, aberrant nucleolar and spindle-associated protein 1 (NUSAP1) expression has been reported in several cancers. However, the biological function and molecular mechanism of NUSAP1 in CRC have not been reported. Here, we demonstrated that NUSAP1 gene expression was notably upregulated in CRC tissues and cell lines (Caco2, LS174T, SW480, and LoVo). Subsequently, SW480 and LoVo cells were transfected with NUSAP1 siRNA, respectively, and the biological function of NUSAP1 was investigated. Results indicated that NUSAP1 silencing by siRNA inhibited CRC cell proliferation, and induces cell apoptosis. Moreover, NUSAP1 knockdown suppressed cell migration, cell invasion, and epithelial-to-mesenchymal transition (EMT). Furthermore, NUSAP1 silencing notably inhibited the mRNA and protein expression level of DNA methyltransferase 1 (DNMT1). DNMT1 overexpression partly rescued the effect of NUSAP1 silencing on colorectal cancer biological function. Taken together, NUSAP1 gene silencing induced cell apoptosis, and inhibited cell proliferation, cell migration, cell invasion, and EMT in colorectal cancer through inhibiting DNMT1 gene expression. These findings indicat that NUSAP1 is a promising molecular target for CRC treatment.

Prognostic value of NUSAP1 in progression and expansion of glioblastoma multiforme.

Nucleolar and spindle-associated protein (NUSAP1) is a microtubule and chromatin-binding protein that stabilizes microtubules to prevent depolymerization, maintains spindle integrity. NUSAP1 could cross-link spindles into aster-like structures, networks and fibers. It has also been found to play roles in progression of several cancers. However, the potential correlation between NUSAP1 and clinical outcome in patients with glioblastoma multiforme (GBM) remains largely unknown. In the current study, we demonstrated that NUSAP1 was significantly up-regulated in GBM tissues compared with adult non-tumor brain tissues both in a validated cohort and a TCGA cohort. In addition, Kaplan-Meier analysis indicated that patients with high NUSAP1 expression had significantly lower OS (P = 0.0027). Additionally, in the TCGA cohort, NUSAP1 expression was relatively lower in GBM patients within the neural and mesenchymal subtypes compared to other subtypes, and associated with the status of several genetic aberrations such as PTEN deletion and wild type IDH1. The present study provides new insights and evidence that NUSAP1 over-expression was significantly correlated with progression and prognosis of GBM. Furthermore, knockdown of NUSAP1 revealed its regulation on G2/M progression and cell proliferation (both in vitro and in vivo). These data demonstrate that NUSAP1 could serve as a novel prognostic biomarker and a potential therapeutic target for GBM.

[Experimental studies on correlation between nucleolus spindle-related protein 1 and the malignant progression and prognosis of human glioblastoma multiforme].

Objective: To investigate the correlation between nucleolus spindle-related protein 1 (NUSAP1) and malignant progression and prognosis of human glioblastoma multiforme (GBM). Methods: RT-PCR and immunohistochemical technique were applied to analyze NUSAP1 expression level in GBM surgical specimens. Correlations between NUSAP1 expression and molecular classification and survival of patients with GBM were also investigated in TCGA database. The gene silencing technique was used to silence NUSAP1 expression in U87 cells, CCK-8 assay was used to detect cell proliferation, flow cytometry was used to detect cell cycle changes, and in vivo tumorigenicity was evaluated after NUSAP1 silencing in tumor-bearing mice. Results: NUSAP1 expression level in GBM was higher than that in non-tumor brain tissue. Survival curve analysis showed that the survival time of GBM patients with high NUSAP1 expression decreased significantly (P<0.01). NUSAP1 expression was relatively lower in mesenchymal and neural molecular subtypes of GBM, when compared with the other two molecular subtypes. And it was closely related with specific genetic aberrations (such as PTEN loss and IDH1 mutation). Silencing NUSAP1 inhibited G2/M cell cycle progression of GBM cells, and inhibited cell proliferation both in vitro and in vivo. Conclusion: Expression of NUSAP1 is closely related to progress and prognosis of GBM, and can be a biomarker reflecting GBM prognosis and act as a therapeutic target with potential clinical application value.

NUSAP1 expression is upregulated by loss of RB1 in prostate cancer cells.

BACKGROUND: Overexpression of NUSAP1 is associated with poor prognosis in prostate cancer, but little is known about what leads to its overexpression. Based on previous observations that NUSAP1 expression is enhanced by E2F1, we hypothesized that NUSAP1 expression is regulated, at least in part, by loss of RB1 via the RB1/E2F1 axis. METHODS: Using Significance Analysis of Microarrays, we examined RB1, E2F1, and NUSAP1 transcript levels in prostate cancer gene expression datasets. We compared NUSAP1 expression levels in DU145, LNCaP, and PC-3 prostate cancer cell lines via use of cDNA microarray data, RT-qPCR, and Western blots. In addition, we used lentiviral expression constructs to knockdown RB1 in prostate cancer cell lines and transient transfections to knockdown E2F1, and investigated RB1, E2F1, and NUSAP1 expression levels with RT-qPCR and Western blots. Finally, in DU145 cells or PC-3 cells that stably underexpress RB1, we used proliferation and invasion assays to assess whether NUSAP1 knockdown affects proliferation or invasion. RESULTS: NUSAP1 transcript levels are positively correlated with E2F1 and negatively correlated with RB1 transcript levels in prostate cancer microarray datasets. NUSAP1 expression is elevated in the RB1-null DU145 prostate cancer cell line, as opposed to LNCaP and PC-3 cell lines. Furthermore, NUSAP1 expression increases upon knockdown of RB1 in prostate cancer cell lines (LNCaP and PC-3) and decreases after knockdown of E2F1. Lastly, knockdown of NUSAP1 in DU145 cells or PC-3 cells with stable knockdown of RB1 decreases proliferation and invasion of these cells. CONCLUSION: Our studies support the notion that NUSAP1 expression is upregulated by loss of RB1 via the RB1/E2F1 axis in prostate cancer cells. Such upregulation may promote prostate cancer progression by increasing proliferation and invasion of prostate cancer cells. NUSAP1 may thus represent a novel therapeutic target.

Unveiling NUSAP1 as a common gene signature linking chronic HBV infection and HBV-related HCC.

BACKGROUND: Hepatitis B virus (HBV) is a significant contributor to the development of hepatocellular carcinoma (HCC). Chronic HBV infection (CHB) facilitates disease progression through various mechanisms. However, the specific factor responsible for the progression of HBV infection to HCC remains unresolved. This study aims to identify the hub gene linking CHB and HBV-related HCC through bioinformatic analysis and experimental verification. METHODS: Differentially expressed genes (DEGs) were identified in datasets encompassing CHB and HBV-HCC patients from the GEO database. Enriched pathways were derived from GO and KEGG analysis. Hub genes were screened by protein-protein interaction (PPI) analysis and different modules in Cytoscape software. The significance of the selected hub gene in prognosis was further assessed in validated datasets. The effects of hub genes on cell growth and apoptosis were further determined in functional experiments. RESULTS: The study revealed upregulation of NUSAP1 in CHBs and HBV-HCCs. High expression of NUSAP1 served as an independent predictor for poor prognosis of liver cancers. Functional experiments demonstrated that NUSAP1 promotes cell growth, influences cell cycle process, and protects cells from apoptosis in HepG2.2.15 cells. CONCLUSION: NUSAP1 serves as a poor prognostic indicator for liver cancers, and potentially plays a crucial role in HBV-HCC progression by promoting proliferation and inhibiting apoptosis.

NUSAP1-LDHA-Glycolysis-Lactate feedforward loop promotes Warburg effect and metastasis in pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by hypoxia and hypovascular tumor microenvironment. Nucleolar and spindle associated protein 1 (NUSAP1) is a microtubule-associated protein that is known to be involved in cancer biology. Our study aimed to investigate the role of NUSAP1 in glycolytic metabolism and metastasis in PDAC. Expression and prognostic value of NUSAP1 in PDAC and common gastrointestinal tumors was evaluated. The function of NUSAP1 in PDAC progression was clarified by single-cell RNA-seq and further experiments in vitro, xenograft mouse model, spontaneous PDAC mice model and human tissue microarray. The downstream genes and signaling pathways regulated by NUSAP1 were explored by RNA-Seq. And the regulation of NUSAP1 on Lactate dehydrogenase A (LDHA)-mediated glycolysis and its underlying mechanism was further clarified by CHIP-seq. NUSAP1 was an independent unfavorable predictor of PDAC prognosis that playing a critical role in metastasis of PDAC by regulating LDHA-mediated glycolysis. Mechanically, NUSAP1 could bind to c-Myc and HIF-1α that forming a transcription regulatory complex localized to LDHA promoter region and enhanced its expression. Intriguingly, lactate upregulated NUSAP1 expression by inhibiting NUSAP1 protein degradation through lysine lactylated (Kla) modification, thus forming a NUSAP1-LDHA-glycolysis-lactate feedforward loop. The NUSAP1-LDHA-glycolysis-lactate feedforward loop is one of the underlying mechanisms to explain the metastasis and glycolytic metabolic potential in PDAC, which also provides a novel insights to understand the Warburg effect in cancer. Targeting NUSAP1 would be an attractive paradigm for PDAC treatment.

Comprehensive pan-cancer analysis reveals NUSAP1 is a novel predictive biomarker for prognosis and immunotherapy response.

Nucleolar and spindle-associated protein 1 (NUSAP1) is a microtubule-associated protein that plays a crucial role in mitosis. Despite initial reports suggesting a potential involvement of NUSAP1 in tumor progression and malignant cell regulation, there has been no systematic analysis of its role in the tumor immune microenvironment, nor its predictive value for prognosis and immunotherapy response across different cancer types. In this study, we analyze NUSAP1 mRNA and protein expression levels in various human normal and tumor tissues, using data from TCGA, GTEx, CPTAC, HPA databases, and clinical samples. Our findings reveal that NUSAP1 is highly expressed in multiple tumor tissues across most cancer types and is primarily expressed in malignant and immune cells, according to single-cell sequencing data from the TISCH database. Prognostic analysis based on curated survival data from the TCGA database indicates that NUSAP1 expression levels can predict clinical outcomes for 26 cancer types. Furthermore, Gene Set Enrichment Analysis (GSEA) suggests that NUSAP1 promotes cell proliferation, tumor cell invasion, and regulation of anti-tumor response. Analysis of immune score, immune cell infiltration, and anti-cancer immunity cycle using ESTIMATE, TIMER, and TIP databases show that high NUSAP1 levels are associated with low CD4+T and NKT cell infiltration but high Th2 and MDSC infiltration, inversely correlated with antigen-presenting molecules and positively correlated with a variety of immune negative regulatory molecules. Notably, patients with melanoma, lung, and kidney cancer with high NUSAP1 expression levels have shorter survival times and lower immunotherapy response rates. Using Cmap analysis, we identify Entinostat and AACOCF3 as potential inhibitors of NUSAP1-mediated pro-oncogenic effects. In vitro and in vivo experiments further confirm that NUSAP1 knockdown significantly reduces the proliferation ability of A549 and MCF-7 cells. Overall, our study highlights the potential of NUSAP1 expression as a novel biomarker for predicting prognosis and immuno-therapeutic efficacy across different human cancers and suggests its potential for developing novel antitumor drugs or improving immunotherapy.

NUSAP1 regulates basal cell carcinoma migration, invasion and DNA damage through activation of the Hedgehog signaling pathway.

Background: Basal cell carcinoma (BCC) is a prevalent cutaneous cancer with an increasing incidence. Nucleolar and spindle associated protein 1 (NUSAP1) is a cell proliferation-related protein that participates in the development of various cancers. However, its role and mechanism in BCC remain elusive. Methods: The expression of NUSAP1 was detected by western blot. Gain- and loss-of-function assays were performed through the transfection of overexpression plasmid of NUSAP1 and si NUSAP1 into TE354.T cells. The role and mechanism of action of NUSAP1 in BCC were explored by cell counting kit-8 (CCK-8), colony formation, transwell, flow cytometry and western blot assays. Results: NUSAP1 was highly expressed in TE354.T cells. Overexpression of NUSAP1 enhanced cell viability, colony forming numbers, numbers of migrated and invasive cells and the relative protein expression of RAD51, but reduced the apoptosis rate and the relative protein expression of γH2AX in TE354.T cells. Inverse results were obtained in these indicators after TE354.T cells were downregulated with NUSAP1. Moreover, the relative expression of proteins involved in the Hedgehog signaling pathway was increased by transfection of the overexpression plasmid of NUSAP1 into TE354.T cells, but decreased by the transfection of si NUSAP1 into TE354.T cells. Conclusion: Both gain- and loss-of-function results revealed that NUSAP1 promoted proliferation, migration and invasion but attenuated apoptosis and DNA damage in BCC, which was involved in the activation of the Hedgehog signaling pathway.