Lentivirus-mediated silencing of spindle and kinetochore-associated protein 1 inhibits the proliferation and invasion of neuronal glioblastoma cells

SKA1 promotes tumor metastasis via SAFB-mediated transcription repression of DUSP6 in clear cell renal cell carcinoma

The most hostile form of urologic cancer, clear cell renal cell carcinoma (ccRCC), has a high fatality rate and poor prognosis due to tumor metastasis at initial presentation. The complex process driving ccRCC metastasis is still unknown, though. In this study, we demonstrate that Spindle and kinetochore-associated protein 1 (SKA1) expression is significantly upregulated in ccRCC tissues and associated with aggressive clinicopathologic characteristics. Functionally, SKA1 knockdown on ccRCC cells reduced cancer cell motility both in vivo and in vitro research. These bioactivities of SKA1 may be brought on by its specific interaction with scaffold attachment factor B, according to the proposed mechanism (SAFB), which could further depress the transcription of dual specificity phosphatase 6 (DUSP6). Our findings may provide a new way of researching SKA1-regulated tumor metastasis, and indicate that SKA1 is a prospective therapeutic target for renal carcinoma.

shRNA‑mediated knockdown of KNTC1 inhibits non-small-cell lung cancer through regulating PSMB8

In view of the important roles played by Kinetochore proteins in mitosis, we believed that they may contribute to the development and progression of human cancers, which has been reported recently elsewhere. Kinetochore-associated 1 (KNTC1) participates in the segregation of sister chromatids during mitosis, the effects of which on non-small-cell lung cancer (NSCLC) remain unclear. Here, we sought to identify the biological significance of KNTC1 in NSCLC. KNTC1 protein expression in NSCLC tissues was investigated by immunohistochemistry. Lentivirus delivered short hairpin RNA (shRNA) was utilized to establish KNTC1 silence NSCLC cell lines. The effects of KNTC1 depletion on NSCLC cell proliferation, migration, apoptosis, and tumor formation were analyzed by MTT assay, wound-healing assay, transwell assay, flow cytometry assay, and in nude mouse models in vivo. After KNTC1 reduction, NSCLC cell viability, proliferation, migration, and invasion were restrained. A xenograft tumor model was also provided to demonstrate the inhibited tumorigenesis in NSCLC. In addition, the downstream mechanism analysis indicated that KNTC1 depletion was positively associated with PSMB8. The findings of the present study suggested that KNTC1 may have a pivotal role in mediating NSCLC progression and may act as a novel therapeutic target for NSCLC.

Identification of Spindle and Kinetochore-Associated Family Genes as Therapeutic Targets and Prognostic Biomarkers in Pancreas Ductal Adenocarcinoma Microenvironment

Aim

The role of spindle and kinetochore-associated (SKA) genes in tumorigenesis and cancer progression has been widely studied. However, so far, the oncogenic involvement of SKA family genes in pancreatic cancer and their prognostic potential remain unknown.

Methods

Here, we carried out a meta-analysis of the differential expression of SKA genes in normal and tumor tissue. Univariate and multivariate survival analyses were done to evaluate the correlation between SKA family gene expression and pancreas ductal adenocarcinoma (PDAC) prognosis. Joint-effect and stratified survival analysis as well as nomogram analysis were used to estimate the prognostic value of genes. The underlying regulatory and biological mechanisms were identified by Gene set enrichment analysis. Interaction between SKA prognosis-related genes and immune cell infiltration was assessed using the Tumor Immune Estimation Resource tool.

Results

We find that SKA1-3 are highly expressed in PDAC tissues relative to non-cancer tissues. Survival analysis revealed that high expression of SKA1 and SKA3 independently indicate poor prognosis but they are not associated with relapse-free survival. The prognostic value of SKA1 and SKA3 was further confirmed by the nomogram, joint-effect, and stratified survival analysis. Analysis of underlying mechanisms reveals that these genes influence cancer-related signaling pathways, kinases, miRNA, and E2F family genes. Notably, prognosis-related genes are inversely correlated with several immune cells infiltrating levels.

Conclusion

We find that SKA1 and SKA3 expression correlates with prognosis and immune cell infiltration in PDAC, highlighting their potential as pancreatic cancer prognostic biomarkers.

SKA1 regulates actin cytoskeleton remodelling via activating Cdc42 and influences the migration of pancreatic ductal adenocarcinoma cells

Objectives

Spindle and kinetochore–associated protein 1(SKA1), originally identified as a protein essential for proper chromosome segregation, has been recently linked to multiple malignancies. This study aimed to explore the biological, clinical role and molecular mechanism of SKA1 in pancreatic carcinogenesis.

Materials and Methods

SKA1 expression was detected in 145 pancreatic ductal adenocarcinoma (PDAC) specimens by immunohistochemistry. Biological behaviour assays were used to determine the role of SKA1 in PDAC progression in vitro and in vivo. Using isobaric tags for relative and absolute quantitation (iTRAQ), SKA1’s downstream proteins were examined. Moreover, cytochalasin B and ZCL278 were used to explore the changes of SKA1‐induced signalling and cell morphology, with further confirmation by immunoblotting and immunofluorescence assays.

Results

Increased SKA1 expression was significantly correlated with tumour size and cellular differentiation degree in PDAC tissues. Furthermore, elevated levels of SKA1 reflected shorter overall survival (P = .019). As for biological behaviour, SKA1 acted as a tumour promotor in PDAC, overexpression of SKA1 facilitates cell proliferation, migration and invasion in vitro and in vivo. Mechanistically, we demonstrated that SKA1 enhanced pancreatic cancer aggressiveness by inhibiting G2/M arrest and regulating actin cytoskeleton organization via activating Cdc42.

Conclusions

This study revealed novel roles for SKA1 as an important regulator of actin cytoskeleton organization and an oncogene in PDAC cells, which may provide insights into developing novel therapeutics.

SKA1 promotes malignant phenotype and progression of glioma via multiple signaling pathways

Background

Spindle and kinetochore associated protein 1 (SKA1) is a protein involved in chromosome congression and mitosis. It has been found to be upregulated and oncogenic in several human cancers. Herein, we investigated the precise role of SKA1 in the progression and malignant phenotype of human glioma.

Methods

Bioinformatic analysis was carried out based on the RNA-seq data and corresponding clinical data from GEO, TCGA and CGGA databases. Western blot was performed to analyze the expression of SKA1 in clinical samples and signaling pathway proteins in glioma cells, respectively. CCK8 assay, colony forming assay and EdU assay were performed to assess the cell viability. Cell migration and invasion assays were also performed. Moreover, xenograft model was established and the expression of SKA1 was assessed in the xenograft by immunohistochemistry.

Results

SKA1 expression is positively correlated with glioma grade and could be a promising biomarker for GBM. Moreover, overexpression of SKA1 may lead to poor prognosis in glioma. Downregulation of SKA1 attenuated cell viability, migration, and invasion in U251, U87, LN229 and T98 cells. Furthermore, GSEA analysis demonstrated that SKA1 was involved in the cell cycle, EMT pathway as well as Wnt/β-catenin signaling pathway, which were then confirmed with Western blot analysis.

Conclusion

SKA1 promotes malignant phenotype and progression of glioma via multiple pathways, including cell cycle, EMT, Wnt/β-catenin signaling pathway. Therefore, SKA1 could be a promising therapeutic target for the treatment of human gliomas.

Essential genes shape cancer genomes through linear limitation of homozygous deletions

The landscape of somatic acquired deletions in cancer cells is shaped by positive and negative selection. Recurrent deletions typically target tumor suppressor, leading to positive selection. Simultaneously, loss of a nearby essential gene can lead to negative selection, and introduce latent vulnerabilities specific to cancer cells. Here we show that, under basic assumptions on positive and negative selection, deletion limitation gives rise to a statistical pattern where the frequency of homozygous deletions decreases approximately linearly between the deletion target gene and the nearest essential genes. Using DNA copy number data from 9,744 human cancer specimens, we demonstrate that linear deletion limitation exists and exposes deletion-limiting genes for seven known deletion targets (CDKN2A, RB1, PTEN, MAP2K4, NF1, SMAD4, and LINC00290). Downstream analysis of pooled CRISPR/Cas9 data provide further evidence of essentiality. Our results provide further insight into how the deletion landscape is shaped and identify potentially targetable vulnerabilities.

Deconvolution and network analysis of IDH-mutant lower grade glioma predict recurrence and indicate therapeutic targets

Aim: IDH-mutant lower grade glioma (LGG) has been proven to have a good prognosis. However, its high recurrence rate has become a major therapeutic difficulty. Materials & methods: We combined epigenomic deconvolution and a network analysis on The Cancer Genome Atlas IDH-mutant LGG data. Results: Cell type compositions between recurrent and primary gliomas are significantly different, and the key cell type that determines the prognosis and recurrence risk was identified. A scoring model consisting of four gene expression levels predicts the recurrence risk (area under the receiver operating characteristic curve = 0.84). Transcription factor PPAR-α explains the difference between recurrent and primary gliomas. A cell cycle-related module controls prognosis in recurrent tumors. Conclusion: Comprehensive deconvolution and network analysis predict the recurrence risk and reveal therapeutic targets for recurrent IDH-mutant LGG.

SKA1 overexpression is associated with poor prognosis in hepatocellular carcinoma

BACKGROUND

SKA1, an important mitosis protein, has been indicated in the initiation and progression of several malignancies. However, its clinical significance in hepatocellular carcinoma (HCC) remain to be elucidated.

METHODS

mRNA expression of SKA1 was examined in 126 HCC and paired non-neoplastic tissues using real-time PCR and validated in The Cancer Genome Atlas (TCGA) database. SKA1 protein expression was detected using immunohistochemistry in the 126 HCC tissues and its associations with clinicopathological parameters and prognosis were analyzed. Hierarchical cluster analysis and gene set enrichment analysis (GSEA) were performed in selected Gene Expression Omnibus data sets.

RESULTS

SKA1 mRNA expression was significantly elevated in HCC tissues from both local hospital and TCGA database. Immunohistochemistry revealed that increased SKA1 expression was present in 65 of the 126 cases and was significantly associated with higher serum alpha-fetoprotein concentration, larger tumor size and higher TNM stage. Patients with positive SKA1 expression showed significantly worse overall and relapse-free survival. Multivariate Cox regression analysis revealed that SKA1 was an independent predictor of patient prognosis. Gene expression profiling analysis of public data showed that high-SKA1 expression HCC tissues had similar gene expression profiles with fetal liver tissues. Moreover, GSEA showed that genes up-regulated in high SKA1 HCC subgroup were significantly enriched in cell cycle pathway, while genes down-regulated were significantly enriched in apoptosis pathway.

CONCLUSIONS

Our findings indicate that the oncofetal gene SKA1 might be involved in the progression of the HCC and could serve as a prognostic marker for HCC.

Regulation of spindle and kinetochore-associated protein 1 by antitumor miR-10a-5p in renal cell carcinoma

Analysis of our original microRNA (miRNA) expression signature of patients with advanced renal cell carcinoma (RCC) showed that microRNA‐10a‐5p (miR‐10a‐5p) was significantly downregulated in RCC specimens. The aims of the present study were to investigate the antitumor roles of miR‐10a‐5p and the novel cancer networks regulated by this miRNA in RCC cells. Downregulation of miR‐10a‐5p was confirmed in RCC tissues and RCC tissues from patients treated with tyrosine kinase inhibitors (TKI). Ectopic expression of miR‐10a‐5p in RCC cell lines (786‐O and A498 cells) inhibited cancer cell migration and invasion. Spindle and kinetochore‐associated protein 1 (SKA1) was identified as an antitumor miR‐10a‐5p target by genome‐based approaches, and direct regulation was validated by luciferase reporter assays. Knockdown of SKA1 inhibited cancer cell migration and invasion in RCC cells. Overexpression of SKA1 was observed in RCC tissues and TKI‐treated RCC tissues. Moreover, analysis of The Cancer Genome Atlas database demonstrated that low expression of miR‐10a‐5p and high expression of SKA1 were significantly associated with overall survival in patients with RCC. These findings showed that downregulation of miR‐10a‐5p and overexpression of the SKA1 axis were highly involved in RCC pathogenesis and resistance to TKI treatment in RCC.

Overexpression of spindle and kinetochore-associated protein 1 contributes to the progression of prostate cancer

Spindle and kinetochore-associated protein 1 is a microtubule-binding subcomplex of the outer kinetochore that is essential for proper chromosome segregation. Recently, spindle and kinetochore-associated protein 1 has been highlighted as a biomarker in various cancers; however, the precise role of spindle and kinetochore-associated protein 1 in prostate cancer remains unknown. This study aims to evaluate whether spindle and kinetochore-associated protein 1 affects the biological behaviors of prostate cancer. We investigated the expression of spindle and kinetochore-associated protein 1 in a series of prostate cancer tissues as well as in a panel of prostate cancer cell lines. Cell proliferation, migration, and invasion were evaluated in spindle and kinetochore-associated protein 1 knockdown prostate cancer cell lines by MTT and Transwell assays. Our results showed that the expression of spindle and kinetochore-associated protein 1 was remarkably upregulated in prostate cancer at both messenger RNA and protein levels compared with non-cancerous tissue. Knockdown of spindle and kinetochore-associated protein 1 repressed the ability of cell proliferation, migration, and invasion of prostate cancer cells. Moreover, inhibition of spindle and kinetochore-associated protein 1 could inhibit the activity of AKT and ERK pathway. In conclusion, our findings suggest that spindle and kinetochore-associated protein 1 could serve as a potential therapeutic target in prostate cancer patients.

SKA1 regulates the metastasis and cisplatin resistance of non-small cell lung cancer

Currently, chemotherapy with platinum-based drugs including cisplatin is the most effective therapy for the treatment of non-small cell lung carcinoma (NSCLC). However, the efficacy of chemotherapy is limited due to commonly developed drug resistance. Spindle and kinetochore-associated complex subunit 1 (SKA1) is part of a complex essential for stabilizing the attachment of spindle microtubules to kinetochores and for maintaining the metaphase plate during mitosis. In the present study, we aimed to investigate the role of SKA1 in the process of metastasis and drug resistance of NSCLC. We completed a series of experiments to investigate the function of SKA1 in NSCLC metastasis and drug resistance including qRT-PCR, immunohistochemistry and western blotting, as well as MTT, BrdU, wounded healing, Transwell and gelatin zymography assays. We demonstrated that the expression levels of SKA1 were elevated in NSCLC and were correlated with cancer progression and malignancy. We also reported that SKA1 positively regulated the proliferation and metastatic ability of NSCLC cells. In addition, we determined that SKA1 contributed to cisplatin resistance in NSCLC cells by protecting these cells from cisplatin-induced cell apoptosis. SKA1 also appeared to regulate the ERK1/2 and the Akt-mediated signaling pathways in NSCLC cells. SKA1 is required for metastasis and cisplatin resistance of non-small cell lung cancer.

Expression of Spindle and Kinetochore-Associated Protein 1 Is Associated with Poor Prognosis in Papillary Thyroid Carcinoma

AIM

Spindle and kinetochore-associated protein 1 (SKA1) is one subtype of SKA, whose protein can make spindle microtubules attach steadily to the kinetochore in the middle of mitosis. At present, there are fewer researches on the relationship between SKA1 expression and tumor development.

METHODS

In this study, immunohistochemical analysis was used to determine the expression of SKA1 in papillary thyroid carcinoma (PTC) and adjacent tissues. We used quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analysis to further verify the results.

RESULTS

We found that SKA1 expression was significantly higher in PTC tissues than normal adjacent tissues (P < 0.05). There existed a significant correlation among a higher SKA1 expression, including lymphoid node (P = 0.005), clinical stage (P = 0.015), and extrathyroid invasion (P = 0.004). Survival analysis showed high SKA1 expression in PTC patients more likely to relapse after surgery.

CONCLUSION

High SKA1 expression is predictive of poor prognosis of PTC, implying that SKA1 may be a promising new target for targeted therapies for PTC.