[Expression of NUSAP1 and its relationship with prognosis in non-small cell lung cancer]

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 and PCLAF (KIA0101) Downregulation by Neoadjuvant Therapy is Associated with Better Therapeutic Outcomes and Survival in Breast Cancer

Purpose. To evaluate whether changes in genomic expression that occur beginning with breast cancer (BC) diagnosis and through to tumor resection after neoadjuvant chemotherapy (NCT) reveal biomarkers that can help predict therapeutic response and survival. Materials and Methods. We determined gene expression profiles based on microarrays in tumor samples from 39 BC patients who showed pathologic complete response (pCR) or therapeutic failure (non-pCR) after NCT (cyclophosphamide-doxorubicin/epirubicin). Based on unsupervised clustering of gene expression, together with functional enrichment analyses of differentially expressed genes, we selected NUSAP1, PCLAF, MME, and DST. We evaluated the NCT response and the expression of these four genes in BC histologic subtypes. In addition, we study the presence of tumor-infiltrating lymphocytes. Finally, we analyze the correlation between NUSAP1 and PCLAF against disease-free survival (DFS) and overall survival (OS). Results. A signature of 43 differentially expressed genes discriminated pCR from non-pCR patients (|fold change >2|, false discovery rate <0.05) only in biopsies taken after surgery. Patients achieving pCR showed downregulation of NUSAP1 and PCLAF in tumor tissues and increased DFS and OS, while overexpression of these genes correlated with poor therapeutic response and OS. These genes are involved in the regulation of mitotic division. Conclusions. The downregulation of NUSAP1 and PCLAF after NCT is associated with the tumor response to chemotherapy and patient survival.

ANKRD22 enhances breast cancer cell malignancy by activating the Wnt/β-catenin pathway via modulating NuSAP1 expression

Breast cancer is one of the most prevalent malignancies in women worldwide. Although great advancements have been achieved in the diagnosis and treatment of breast cancer, the prognosis of patients with breast cancer is still poor due to distal recurrence and metastasis after surgery. This study aimed to assess the role of ankyrin repeat domain 22 (ANKRD22) in the progression of breast cancer and investigate the molecular mechanism. Using immunohistochemistry, we demonstrated that the expression level of ANKRD22 in human breast cancer tissues was significantly higher than that in normal breast tissues. ANKRD22 knockdown inhibited the proliferation, invasion, and epithelial-mesenchymal transition (EMT) of breast cancer cells, as confirmed by BrdU, colony formation, transwell, and immunoblot assays. Immunoblot assays further indicated that ANKRD22 regulated the expression of nucleolar and spindle-associated protein 1 (NuSAP1) and then caused the activation of Wnt/β-catenin signaling pathway. Moreover, overexpression of NUSAP1 reversed the inhibitory effects of ANKRD22 knockdown on the proliferation, invasion, and EMT of breast cancer cells. In summary, this study demonstrated that ANKRD22 enhanced breast cancer cell malignancy by activating the Wnt/β-catenin pathway via modulating NuSAP1 expression, which might shed light on new therapeutic approaches for breast cancer.

NUSAP1 Promotes Gastric Cancer Tumorigenesis and Progression by Stabilizing the YAP1 Protein

The Yes-associated protein (YAP1) is a main effector of the canonical Hippo pathway, which contributes greatly to tumor initiation, progression, and metastasis in multiple cancers, including gastric cancer (GC). Due to limited knowledge of YAP1 upregulation in cancer, it is a great challenge of therapeutic targets toward the Hippo-YAP1 pathway. Here, we identify nucleolar spindle-associated protein 1 (NUSAP1) as a novel binding partner of YAP1. The upregulation of NUSAP1 is associated with unfavorable clinical outcomes in GC patients, and NUSAP1 depletion impairs its oncogenic properties in vitro and in a xenograft model. Mechanistically, we discovered that NUSAP1 functions as a positive regulator of YAP1 protein stability, thereby inducing the transcription of Hippo pathway downstream target genes, such as CTGF and CYR61. More interestingly, we find that the cancer-promoting effects of NUSAP1 on GC cell growth, migration, and invasion are mainly mediated by YAP1. Furthermore, aberrant expression of NUSAP1 and YAP1 is highly correlated in GC cell lines and tissues. We herein clarify the role of the oncogenic NUSAP1-YAP1 axis in GC tumorigenesis and progression and, therefore, provide novel therapeutic targets for GC treatment.