SKA3 Promotes tumor growth by regulating CDK2/P53 phosphorylation in hepatocellular carcinoma

Current research of the Notch pathway in hepatocellular carcinoma

Notch signaling is a widely preserved communication pathway that supports essential cellular functions by allowing adjacent cells to interact. The Notch signaling pathway consists of Notch ligands (DSL proteins), Notch receptors, DNA-binding proteins, and downstream target genes. Hepatocellular carcinoma (HCC) represents the predominant cause of cancer-related deaths globally and poses a significant threat to human health. For highly malignant HCC, current treatment options, including chemotherapy, radiotherapy, immunotherapy, targeted therapies, and surgical procedures, often have poor prognoses. Therefore, there is a need to explore additional therapeutic strategies. Many studies have found that abnormal activation of the Notch signaling pathway contributes to tumor initiation and progression by promoting HCC proliferation, metastasis, stem cell-like properties, and drug resistance. In this research, we reveal the composition and activation mechanisms of the Notch signaling pathway, as well as the molecular mechanism underlying its aberrant activation in HCC. Furthermore, we summarize recent advances in targeting Notch signaling for the treatment of HCC. This review aims to highlight the promising potential of investigating the Notch pathway as a therapeutic target in HCC.

SKA3 promotes lung adenocarcinoma progression via the EGFR/E2F1/SKA3/integrin β1 signaling loop

Spindle and kinetochore-associated complex subunit 3 (SKA3) contributes to tumor growth and metastasis, but its specific roles have not been clearly elucidated. In this study, we found that SKA3 contributed to lung adenocarcinoma (LUAD) progression by interacting with integrin β1. The expression characteristics of SKA3 in LUAD patients were analyzed by The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets and validated in 33 paired LUAD tissues by immunohistochemistry. Our data confirmed that SKA3 was a crucial regulator of LUAD progression and was associated with worse patient survival. In vitro and in vivo studies showed that SKA3 increased cell migration and invasion. Mechanistically, it was demonstrated that SKA3 could bind to integrin β1 and promote its activation, which further promoted the activation of EGFR. As a positive feedback loop, the activation of EGFR in turn promoted the expression of SKA3 via E2F1-mediated transcriptional regulation. Inhibition of EGFR with AZD9291 blocked SKA3 signaling induced by E2F1. These results indicated that SKA3 was crucial for the activation of EGFR and its downstream signaling pathway. Our findings uncovered the oncogenic role of SKA3 in LUAD progression and elucidated a novel EGFR/E2F1/SKA3/integrin β1 signaling loop, providing a potential SKA3-directed therapeutic strategy for LUAD patients.

Pan-Cancer Analysis Reveals SKA3 as a Potential Diagnostic and Prognostic Biomarker

SKA3, an important factor in cell cycle regulation, is involved in spindle assembly and kinetochore function, playing a critical role in maintaining cancer cell proliferation and division. However, its specific roles and regulatory mechanisms in cancer remain not fully understood. Large-scale datasets from multiple public databases, including The Cancer Genome Atlas and Genotype-Tissue Expression, covering various cancer types, were integrated. Systematic analysis revealed that SKA3 exhibits aberrant expression patterns in multiple cancers and is significantly associated with tumor progression and poor patient prognosis in certain cancers. We explored the status of SKA3 gene mutation, gene amplification and promoter region methylation in various tumors. In the context of immunotherapy, we assessed the value of SKA3 in cancer. Analyzing the correlation between SKA3 expression levels and immune checkpoints and immune cell infiltration, we discovered that SKA3 could serve as a novel immunotherapy biomarker across multiple cancers, guiding clinical immunotherapy decisions. Finally, SKA3 knockdown inhibited lung adenocarcinoma cell proliferation and metastasis. In conclusion, this study provides new insights into the role of SKA3 in cancer and offers significant theoretical and experimental evidence for its development as a diagnostic and prognostic biomarker.

SKA1/2/3 is a prognostic and predictive biomarker in esophageal adenocarcinoma and squamous cell carcinoma

BACKGROUND

Esophageal carcinoma (ESCA) ranks among the most prevalent malignant tumors globally. Despite significant advancements in treatment options and improved patient outcomes, the 5-year survival rate remains unsatisfactory. The spindle and kinetochore associated complex subunit 1/2/3 (SKA1/2/3) attached to the kinetochore (KT) in the metaphase of mitosis are implicated in the occurrence and development of various tumors. However, the expression patterns, diagnostic significance and prognostic implications of SKA1/2/3 in ESCA have not been comprehensively determined.

METHODS

TCGA, UALCAN, Kaplan-Meier Plotter, and TIMER databases were leveraged to dissect the expression patterns, prognostic implications and diagnostic value of SKA1/2/3 in ESCA patients, as well as to investigate the potential regulatory mechanism of SKA1/2/3 in the onset and progression of ESCA.

RESULTS

In ESCA, SKA1/2/3 exhibited substantial expression, with higher levels relating significantly with clinicopathological features and patient prognosis. Enrichment analysis of genes co-expressed with SKA1/2/3 highlighted their involvement in the cell cycle, DNA replication and p53 signaling pathway. Protein-protein interaction (PPI) analysis identified ten hub genes that were not only markedly upregulated but also portended a poor prognosis in ESCA. Additionally, immune infiltration assays uncovered a significant link between SKA1/2/3 expression and the immune cell infiltration within ESCA. Silencing of SKA1/2/3 significantly suppresses cell proliferation and migration, while concurrently promoting apoptosis in ESCA cells.

CONCLUSIONS

SKA1/2/3 may serve as promising biomarkers for the prognosis and diagnosis of ESCA, which holds promise as a novel therapeutic target for the disease.

Prognostic and immunological values of SKA3 for overall survival in lung adenocarcinoma and its RNA binding protein involved mechanisms

This article aimed to investigate the correlations among SKA3 expression and prognosis, clinical relevance, tumor immunity, and RNA-binding protein (RBP)-involved mechanisms for overall survival (OS) in lung adenocarcinoma (LUAD). To explore the SKA3 expression level in LUAD by analyzing the genomic data as well as related clinical characteristics from the database of TCGA. Nomogram and gene set enrichment analysis (GSEA) were applied, respectively, to evaluate the performance of SKA3 in LUAD. Correlations between SKA3 and immunity and RBP-involved mechanisms were also performed. SKA3 had a higher expression level in LUAD samples than in adjacent normal lung samples, with shorter survival times in the high-SKA3-expressed LUAD subgroup (P < 0.05). qRT-PCR results remained consistent (P < 0.05). Uni-/multivariate Cox analyses revealed that SKA3 could have independent prognostic ability for LUAD (both P < 0.05). The nomogram model constructed with clinical pathological parameters and SKA3 expression levels predicted OS rates for LUAD and GSEA revealed SKA3-related pathways. In aspects of tumor immunity, SKA3 was significantly involved with tumor neoantigen burden, tumor mutational burden, immune cell pathways, and immune checkpoint inhibitor (ICI) molecules (all P < 0.05). The CellMiner database also found significant correlations between SKA3 and the antitumor drug sensitivity of chemotherapy, fenretinide, and PX-316. Besides, a total of nine LncRNA/RBP/SKA3 networks were revealed in LUAD for their RBP-involved mechanisms. SKA3 could serve as a potential biomarker for OS prognosis and immunotherapy in LUAD. LncRNA/RBP/SKA3 networks were identified in LUAD for their RBP-involved mechanisms, paving the way for further experimental verifications.

SKA3 Expression as a Prognostic Factor for Patients with Pancreatic Adenocarcinoma

The spindle and kinetochore-associated complex subunit 3 (SKA3) is a protein essential for proper chromosome segregation during mitosis and thus responsible for maintaining genome stability. Although its involvement in the pathogenesis of various cancer types has been reported, the potential clinicopathological significance of SKA3 in pancreatic ductal adenocarcinoma (PDAC) has not been fully elucidated. Therefore, this study aimed to assess clinicopathological associations and prognostic value of SKA3 in PDAC. For this purpose, in-house immunohistochemical analysis on tissue macroarrays (TMAs), as well as a bioinformatic examination using publicly available RNA-Seq dataset, were performed. It was demonstrated that SKA3 expression at both mRNA and protein levels was significantly elevated in PDAC compared to control tissues. Upregulated mRNA expression constituted an independent unfavorable prognostic factor for the overall survival of PDAC patients, whereas altered SKA3 protein levels were associated with significantly better clinical outcomes. The last observation was particularly clear in the early-stage tumors. These findings render SKA3 a promising prognostic biomarker for patients with pancreatic ductal adenocarcinoma. However, further studies are needed to confirm this conclusion.

SKA3 targeted therapies in cancer precision surgery: bridging bench discoveries to clinical applications - review article

Spindle and kinetochore-associated complex subunit 3 (SKA3) is a microtubule-binding subcomplex of the outer kinetochore, which plays a vital role in proper chromosomal segregation and cell division. Recently, SKA3 have been demonstrated its oncogenic role of tumorigenesis and development in cancers. In this review, the authors comprehensively deciphered SKA3 in human cancer from various aspects, including bibliometrics, pan-cancer analysis, and narrative summary. The authors also provided the top 10 predicted drugs targeting SKA3. The authors proposed that SKA3 was a potential target and brought new therapeutic opportunities for cancer patients.

Spindle and kinetochore-related complex subunit 3 has a protumour function in osteosarcoma by activating the Notch pathway

Increasing expression of spindle and kinetochore-related complex subunit 3 (SKA3) is related to the progression of multiple malignancies. However, the role of SKA3 in osteosarcoma remains unexplored. The present study aimed to investigate the relevance of SKA3 in osteosarcoma. Preliminarily, SKA3 expression in osteosarcoma was assessed through The Cancer Genome Atlas (TCGA) analysis, which revealed high levels of SKA3 transcripts in osteosarcoma tissues. Subsequent examination of clinical tissues confirmed the abundant expression of SKA3 in osteosarcoma. Downregulation of SKA3 expression in osteosarcoma cell lines resulted in repressive effects on cell proliferation, migration, invasion, and epithelial-to-mesenchymal transition (EMT), while upregulation of SKA3 expression had the opposite effect. Gene set enrichment analysis (GSEA) revealed that the Notch pathway is enriched in SKA3 high groups based on different expressed genes from the TCGA data. Further investigation showed that the levels of Notch1, Notch1 intracellular domain (NICD1), hairy and enhancer of split 1 (HES1), and hairy/enhancer-of-split related with YRPW motif protein 1 (HEY1) were downregulated in SKA3-silenced osteosarcoma cells, and upregulated in SKA3-overexpressed osteosarcoma cells. Activation of the Notch pathway by increasing NICD1 expression reversed the antitumour effects induced by SKA3 silencing, while deactivation of the Notch pathway diminished the protumour effects induced by SKA3 overexpression. Moreover, SKA3-silenced osteosarcoma cells exhibited a reduced capacity for xenograft formation in nude mice. In conclusion, SKA3 plays a cancer-enhancing role in osteosarcoma through its effect on the Notch pathway. Reducing the expression of SKA3 could be a potential therapeutic approach for treating osteosarcoma.

Network-based pharmacology-based research on the effect and mechanism of the Hedyotis diffusa-Scutellaria Barbata pair in the treatment of hepatocellular carcinoma

The Hedyotis diffusa-Scutellaria officinalis pair (HD-SB) has therapeutic effects on a variety of cancers. Our study was to explore the mechanism of HD-SB in the treatment of hepatocellular carcinoma (HCC). A total of 217 active ingredients of HD-SB and 1196 HCC-related targets were reserved from the TCMSP and the SwissTarget Prediction database, and we got 63 intersection targets from GeneCards. We used a Venn diagram, and Cytoscape found that the three core ingredients were quercetin, luteolin, and baicalein. The PPI analysis showed that the core targets were TP53, CDK2, XPO1, and APP. Molecular docking results showed that these core ingredients had good binding potential with the core targets. HD-SB acts simultaneously on various HCC-related signaling pathways, including proteoglycans in cancer and the P53 signaling pathway. In vitro experiments confirmed that HD-SB can inhibit HepG2 cell proliferation by increasing TP53 and APP levels and decreasing XPO1 and CDK2 levels. This study analyzed active ingredients, core targets, and central mechanisms of HD-SB in the treatment of HCC. It reveals the role of HD-SB in targeting the P53 signaling pathway in the treatment of HCC. We hope that our research could provide a new perspective to the therapy of HCC and find new anticancer drugs.

Stroma-associated FSTL3 is a factor of calcium channel-derived tumor fibrosis

Hepatocellular carcinoma (HCC) is the most widespread histological form of primary liver cancer, and it faces great diagnostic and therapeutic difficulties owing to its tumor diversity. Herein, we aim to establish a unique prognostic molecular subtype (MST) and based on this to find potential therapeutic targets to develop new immunotherapeutic strategies. Using calcium channel molecules expression-based consensus clustering, we screened 371 HCC patients from The Cancer Genome Atlas to screen for possible MSTs. We distinguished core differential gene modules between varying MSTs, and Tumor Immune Dysfunction and Exclusion scores were employed for the reliable assessment of HCC patient immunotherapeutic response rate. Immunohistochemistry and Immunofluorescence staining were used for validation of predicted immunotherapy outcomes and underlying biological mechanisms, respectively. We identified two MSTs with different clinical characteristics and prognoses. Based on the significant differences between the two MSTs, we further identified Follistatin-like 3 (FSTL3) as a potential indicator of immunotherapy resistance and validated this result in our own cohort. Finally, we found that FSTL3 is predominantly expressed in HCC stromal components and that it is a factor in enhancing fibroblast-M2 macrophage signaling crosstalk, the function of which is relevant to the pathogenesis of HCC. The presence of two MSTs associated with the calcium channel phenotype in HCC patients may provide promising directions for overcoming immunotherapy resistance in HCC, and the promotion of FSTL3 expressed in stromal components for HCC hyperfibrosis may be responsible for the poor response rate to immunotherapy in Cluster 2 (C2) patients.

Specific intracellular retention of circSKA3 promotes colorectal cancer metastasis by attenuating ubiquitination and degradation of SLUG

Our previous study demonstrated that tumor-suppressor circular RNAs (circRNAs) can be specifically secreted outside of colorectal cancer (CRC) cells within exosomes to maintain tumor cell fitness. However, whether tumor-driving circRNAs can be specifically retained in cells to facilitate tumor progression remains unknown. In this study, circRNA-seq showed that circSKA3 was significantly upregulated in CRC tissues but downregulated in serum samples from CRC patients. In addition, circSKA3 promoted CRC progression in vitro and in vivo and was retained in CRC cells via a specific cellmotif element. Interestingly, the cellmotif element was also the site of interaction of circSKA3 with SLUG, which inhibited SLUG ubiquitination degradation and promoted CRC epithelial-mesenchymal transition (EMT). Moreover, FUS was identified as a key circularization regulator of circSKA3 that bound to the key element. Finally, we designed and synthesized specific antisense oligonucleotides (ASOs) targeting circularization and cellmotif elements, which repressed circSKA3 expression, abolished the SLUG-circSKA3 interaction, and further inhibited CRC EMT and metastasis in vitro and in vivo.

Hypoxia-induced SKA3 promoted cholangiocarcinoma progression and chemoresistance by enhancing fatty acid synthesis via the regulation of PAR-dependent HIF-1a deubiquitylation

BACKGROUND

Spindle and kinetochore-associated complex subunit 3 (SKA3) plays an important role in cell proliferation by regulating the separation of chromosomes and their division into daughter cells. Previous studies demonstrated that SKA3 was strongly implicated in tumor development and progression. However, the roles of SKA3 in cholangiocarcinoma (CCA) and the underlying mechanisms remain unclear.

METHODS

Next-generation sequencing (NGS) was performed with paired CCA tissues and normal adjacent tissues (NATs). SKA3 was chose to be the target gene because of its remarkably upregulation and unknown function in cholangiocarcinoma in TCGA datasets, GSE107943 datasets and our sequencing results. RT-PCR and immunohistochemistry staining were used to detect the expression of SKA3 in paired CCA tissues and normal adjacent tissues. The SKA3 knockdown and overexpression cell line were constructed by small interfering RNA and lentivirus vector transfection. The effect of SKA3 on the proliferation of cholangiocarcinoma under hypoxic conditions was detected by experiments in vitro and in vivo. RNA-seq was used to find out the differentially expressed pathways in cholangiocarcinoma proliferation under hypoxia regulated by SKA3. IP/MS analysis and Western blot assays were used to explore the specific mechanism of SKA3 in regulating the expression of HIF-1a under hypoxia.

RESULTS

SKA3 was up-regulated in NGS, TCGA and GSE107943 databases and was associated with poor prognosis. Functional experiments in vitro and in vivo showed that hypoxia-induced SKA3 promoted cholangiocarcinoma cell proliferation. RNA-sequencing was performed and verified that SKA3 enhanced fatty acid synthesis by up-regulating the expression of key fatty acid synthase, thus promoting cholangiocarcinoma cell proliferation under hypoxic conditions. Further studies indicated that under hypoxic conditions, SKA3 recruited PARP1 to bind to HIF-1a, thus enhancing the poly ADP-ribosylation (PARylation) of HIF-1a. This PARylation enhanced the binding between HIF-1a and USP7, which triggered the deubiquitylation of HIF-1a under hypoxic conditions. Additionally, PARP1 and HIF-1a were upregulated in CCA and promoted CCA cell proliferation. SKA3 promoted CCA cell proliferation and fatty acid synthesis via the PARP1/HIF-1a axis under hypoxic conditions. High SKA3 and HIF-1a expression levels were associated with poor prognosis after surgery.

CONCLUSION

Hypoxia-induced SKA3 promoted CCA progression by enhancing fatty acid synthesis via the regulation of PARylation-dependent HIF-1a deubiquitylation. Furthermore, increased SKA3 level enhanced chemotherapy-resistance to gemcitabine-based regimen under hypoxic conditions. SKA3 and HIF-1a could be potential oncogenes and significant biomarkers for the analysis of CCA patient prognosis.

High spindle and kinetochore-associated complex subunit-3 expression predicts poor prognosis and correlates with adverse immune infiltration in hepatocellular carcinoma

BACKGROUND

Spindle and kinetochore-associated complex subunit 3 (SKA3) is a malignancy-associated gene that plays a critical role in the regulation of chromosome separation and cell division. However, the molecular mechanism through which SKA3 regulates tumor cell proliferation in hepatocellular carcinoma (HCC) has not been fully elucidated.

AIM

To investigate the molecular mechanisms underlying the role of SKA3 in HCC.

METHODS

SKA3 expression, clinicopathological, and survival analyses were performed using multiple public database platforms, and the results were verified by Western blot and immunohistochemistry staining using collected clinical samples. Functional enrichment analyses were performed to evaluate the biological functions and molecular mechanisms of SKA3 in HCC. Furthermore, the Tumor Immune Estimation Resource and single-sample Gene Set Enrichment Analysis (ssGSEA) algorithms were utilized to investigate the abundance of tumor-infiltrating immune cells in HCC. The response to chemotherapeutic drugs was evaluated by the R package "pRRophetic".

RESULTS

We found that upregulated SKA3 expression was significantly correlated with poor prognosis in patients with HCC. Multivariable Cox regression analysis indicated that SKA3 was an independent risk factor for survival. GSEA revealed that SKA3 expression may facilitate proliferation and migratory processes by regulating the cell cycle and DNA repair. Moreover, patients with high SKA3 expression had significantly decreased ratios of CD8+ T cells, natural killer cells, and dendritic cells. Drug sensitivity analysis showed that the high SKA3 group was more sensitive to sorafenib, sunitinib, paclitaxel, doxorubicin, gemcitabine, and vx-680.

CONCLUSION

High SKA3 expression led to poor prognosis in patients with HCC by enhancing HCC proliferation and repressing immune cell infiltration surrounding HCC. SKA3 may be used as a biomarker for poor prognosis and as a therapeutic target in HCC.

Research Advances in the Role of the Tropomyosin Family in Cancer

Cancer is one of the most difficult diseases for human beings to overcome. Its development is closely related to a variety of factors, and its specific mechanisms have been a hot research topic in the field of scientific research. The tropomyosin family (Tpm) is a group of proteins closely related to the cytoskeleton and actin, and recent studies have shown that they play an important role in various cancers, participating in a variety of biological activities, including cell proliferation, invasion, and migration, and have been used as biomarkers for various cancers. The purpose of this review is to explore the research progress of the Tpm family in tumorigenesis development, focusing on the molecular pathways associated with them and their relevant activities involved in tumors. PubMed and Web of Science databases were searched for relevant studies on the role of Tpms in tumorigenesis and development and the activities of Tpms involved in tumors. Data from the literature suggest that the Tpm family is involved in tumor cell proliferation and growth, tumor cell invasion and migration, tumor angiogenesis, tumor cell apoptosis, and immune infiltration of the tumor microenvironment, among other correlations. It can be used as a potential biomarker for early diagnosis, follow-up, and therapeutic response of some tumors. The Tpm family is involved in cancer in a close relationship with miRNAs and LncRNAs. Tpms are involved in tumor tissue invasion and migration as a key link. On this basis, TPM is frequently used as a biomarker for various cancers. However, the specific molecular mechanism of its involvement in cancer progression has not been explained clearly, which remains an important direction for future research.

TRIM55 Promotes Proliferation of Hepatocellular Carcinoma Through Stabilizing TRIP6 to Activate Wnt/β-Catenin Signaling

PURPOSE

Tripartite motif containing 55 (TRIM55) is a member of the TRIM family and functions as an E3 ubiquitin ligase. It acts as a cancer promoter or suppressor in the malignant processes of multiple cancers. However, its proliferative function in hepatocellular carcinoma (HCC) has been poorly studied, and its underlying molecular mechanism remains unclear. In the present study, we investigated the role of TRIM55 in HCC and its mechanism of promoting HCC proliferation.

MATERIALS AND METHODS

Protein expression levels of TRIM55 were measured in paired HCC and normal tissue samples using immunohistochemical (IHC) staining. The correlation between TRIM55 and clinical features was evaluated by statistical analysis. At the same time, overexpression and knockdown experiments, cycloheximide (CHX) interference experiments, ubiquitination, co-immunoprecipitation and immunofluorescence staining experiments, as well as animal experiments were used to evaluate the potential mechanism that TRIM55 promotes proliferation of hepatocellular carcinoma in vitro and in vivo.

RESULTS

TRIM55 expression in HCC specimens was higher compared with the corresponding non-tumor tissues. The overall survival and disease-free survival time of patients with high TRIM55 expression were shorter than those with low expression of TRIM55. Functionally, TRIM55 promoted the proliferation of HCC cells and accelerated the growth of HCC xenografts. Mechanistically, TRIM55 interacted with thyroid receptor interacting protein 6 (TRIP6) and regulate its stability by influencing the ubiquitination process, thereby affecting the Wnt signaling pathway.

CONCLUSION

Our results indicate that TRIM55 promotes HCC proliferation by activating Wnt signaling pathways by stabilizing TRIP6. Therefore, targeting TRIM55 may be an effective therapeutic strategy to inhibit HCC growth.

Transcription factor ZEB1 regulates PLK1-mediated SKA3 phosphorylation to promote lung cancer cell proliferation, migration and cell cycle

Lung cancer (LC) is one of the most common malignancies worldwide with low 5-year survival rate. The mechanism of spindle and kinetochore-associated complex subunit 3 (SKA3) in LC tumorgenesis remains largely unclear. The expression of SKA3 in LC cells was detected by quantitative PCR. Cell proliferation, migration and cell cycle were evaluated by functional assays including 5-ethynyl-2'-deoxyuridine, wound healing, transwell assays and flow cytometry analysis. Bioinformatics analysis, chromatin immunoprecipitation, luciferase reporter, co-immunoprecipitation and in vitro phosphorylation assays were applied to explore the interactions between zinc finger E-box binding homeobox 1 (ZEB1) and SKA3/polo-like kinase 1 (PLK1). SKA3 is highly expressed in LC cell lines and drives LC cell proliferation, migration and cell cycle. PLK1 also enhances the malignancy of LC cells. PLK1 can mediate SKA3 phosphorylation and enhance the stability of SKA3 protein, thus promoting LC progression. Besides, we found that transcription factor ZEB1 transcriptionally activates SKA3/PLK1 expression, contributing to LC cell malignancy. This study demonstrated that transcription factor ZEB1 modulates PLK1-mediated SKA3 phosphorylation to accelerate LC cell growth, migration and cycle, which might offer novel insight into LC treatment.

Construction and validation of a novel apoptosis-associated prognostic signature related to osteosarcoma metastasis and immune infiltration

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Osteosarcoma is one of the most aggressive diseases which often develops metastasis.

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Apoptosis relates to the recurrence and metastasis of osteosarcoma and the related signature could predict the prognosis of patients.

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A novel apoptosis-associated prognosis signature related to osteosarcoma metastasis and immune infiltration has been developed.

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The signature could help to predict the prognosis of osteosarcoma patients and serve as the potential targets for anti-cancer treatment.

Background

Apoptosis played vital roles in the formation and progression of osteosarcoma. However, no studies elucidated the prognostic relationships between apoptosis-associated genes (AAGs) and osteosarcoma.

Methods

The differentially expressed genes associated with osteosarcoma metastasis and apoptosis were identified from GEO and MSigDB databases. The apoptosis-associated prognostic signature was established through univariate and multivariate cox regression analyses. The Kaplan–Meier (KM) survival curve, ROC curve and nomogram were constructed to investigate the predictive value of this signature. CIBERSORT algorithm and ssGSEA were used to explore the relationships between immune infiltration and AAG signature. The above results were validated in another GEO dataset and the expression of AAGs was also validated in osteosarcoma patient samples by immunohistochemistry.

Results

HSPB1 and IER3 were involved in AAG signature. In training and validation datasets, apoptosis-associated risk scores were negatively related to patient survival rates and the AAG signature was regarded as the independent prognostic factor. ROC and calibration curves demonstrated the signature and nomogram were reliable. GSEA revealed the signature related to immune-associated pathways. ssGSEA indicated that one immune cell and three immune functions were significantly dysregulated. The immunohistochemistry analyses of patients’ samples revealed that AAGs were significantly differently expressed between metastasis and non-metastasis osteosarcomas.

Conclusions

The present study identified and validated a novel apoptosis-associated prognostic signature related to osteosarcoma metastasis. It could serve as the potential biomarker and therapeutic targets for osteosarcoma in the future.

Study on the Prognostic Values of TTC36 Correlated with Immune Infiltrates and Its Methylation in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) remains an incurable disease with a very poor clinical outcome. The purpose of this article was to investigate whether the expression or methylation of tetrapeptide repeat domain 36 (TTC36) could be used as a prognostic marker in hepatocellular carcinoma. TCGA database was used to obtain information on HCC gene expression and the associated clinical features of HCC patients. Differentially expressed genes (DEGs) were screened between 374 HCC specimens and 50 nontumor specimens. The expression and prognostic value of TTC36 were analyzed. The correlations between TTC36 and cancer immune infiltrates were investigated via TIMER. In this study, HCC specimens and nontumor specimens were compared and 35 DEGs were found between them. Among the 35 DEGs, the expression of TTC36 was significantly reduced in HCC samples compared with nontumor samples. Survival tests revealed that patients with low TTC36 expression had a shorter overall survival than patients with high TTC36 expression. TTC36 was found to be an independent predictive factor for HCC in both univariate and multivariate regression analyses. TTC36 was negatively regulated by TTC36 methylation, leading to its low expression in HCC tissues. Immune analysis revealed that TTC36 expression has significant correlations with B cell, T cell CD4+, neutrophil, macrophage, and myeloid dendritic cell. Finally, TTC36 expression was dramatically reduced in HCC cells, and overexpression greatly suppressed HCC cell proliferation and invasion, according to our experimental results. Overall, our data suggested that TTC36 could be applied as a prognostic marker for predicting outcome and immune infiltration in HCC.

MIF/SCL3A2 depletion inhibits the proliferation and metastasis of colorectal cancer cells via the AKT/GSK-3β pathway and cell iron death

This study investigated the mechanisms of migration inhibitory factor (MIF) and solute carrier family 3 member 2 (SLC3A2) in colorectal cancer progression. The levels of MIF and SLC3A2 expression in cells were measured by RT-qPCR. SW480 and SW620 cells were transfected with sh-MIF and sh-SLC3A2, respectively. MIF, SLC3A2, GPX4, E-cadherin and N-cadherin expression were detected by immunofluorescence (IF). CCK8 and Transwell assays were performed to detect cell proliferation and migration. Co-immunoprecipitation (CoIP) was used to measure the binding activity of MIF and SLC3A2. Finally, a nude mouse tumorigenicity assay was used to confirm the functions of MIF and SLC3A2 in colorectal cancer. Results showed that the levels of MIF and SLC3A2 expression were up-regulated in colorectal cancer cells. Inhibition of MIF or SLC3A2 expression prevented cell proliferation, migration, epithelial-mesenchymal transition (EMT) and invasion. In addition, knockdown of MIF and SLC3A2 promoted iron death in SW480 and SW620 cells. CoIP results showed that MIF and SLC3A2 directly interact with each other. Knockdown of both MIF and SLC3A2 inhibited tumour growth and metastasis via the AKT/GSK-3β pathway in vivo. The Akt/GSK-3β pathway was found to participate in regulating MIF and SLC3A2 both in vivo and in vitro. MIF and SLC3A2 might be potential biomarkers for monitoring the treatment of colorectal cancer.

SKA3 is a prognostic biomarker and associated with immune infiltration in bladder cancer

BACKGROUND

Spindle and kinetochore‑associated complex subunit 3 (SKA3) has recently been considered a key regulator of carcinogenesis. However, the connection between SKA3 and immune cell infiltration remains unknown.

METHODS

The current study investigated the expression mode, prognostic effect, and functional role of SKA3 in different tumors, particularly bladder cancer using numerous databases, comprising TIMER, GEPIA, HPA, UALCAN, PrognoScan, and Kaplan-Meier Plotter. Differentially expressed gene and enrichment analyses were implemented on SKA3 using R packages "edgR" and "clusterProfiler". Immunohistochemistry was further used to validate the expression of SKA3 gene in bladder cancer. Following that, the relevance of SKA3 expression to immune infiltration level in bladder cancer was evaluated using TIMER.

RESULTS

Overall, the level of SKA3 expression in tumor tissue significantly increased than in normal tissue. In bladder cancer and other tumors, patients with high SKA3 expression levels had worse overall survival (OS) (p = 0.016), disease-specific survival (DSS) (p = 0.00004), and disease-free survival (DFS) (p = 0.032). Additionally, the major molecular functions for SKA3 included nuclear division, mitotic nuclear division, mitotic sister chromatid segregation, humoral immune response, and cell chemotaxis. Additionally, SKA3 expression was found to be positively associated with enhanced M2 macrophage and T helper (Th) 2 cell infiltration in bladder cancer.

CONCLUSIONS

Our study implies that SKA3 contributes to M2 macrophage and Th2 cell polarization by acting as an oncogene in bladder cancer. SKA3 might be a novel biomarker for evaluating prognosis and immune infiltration in bladder cancer.

p53 m6A modulation sensitizes hepatocellular carcinoma to apatinib through apoptosis

Hepatocellular carcinoma (HCC) is insidious and prone to metastasis and recurrence. Currently, no effective treatment is available for HCC. Furthermore, HCC does not respond to various radio- and chemotherapies, and the molecular mechanism of treatment resistance is unclear. Here, we found that p53 n6-methyladenosine (m⁶A) played a decisive role in regulating HCC sensitivity to chemotherapy via the p53 activator RG7112 and the vascular endothelial growth factor receptor inhibitor apatinib. Our results reveal that p53 activation plays a crucial role in chemotherapy-induced apoptosis and reducing cell viability. Moreover, decreasing m⁶A methyltransferase (e.g., methyltransferase-like 3, METTL3) expression through chemotherapeutic drug combinations reduced p53 mRNA m⁶A modification. p53 mRNA m⁶A modification blockage induced by S-adenosyl homocysteine or siRNA-mediated METTL3 inhibition enhanced HCC sensitivity to chemotherapy. Importantly, we observed that downregulation of METTL3 and upregulation of p53 expression by oral administration of chemotherapy drugs triggered apoptosis and xenograft tumor growth inhibition in nude mice. Based on these findings, we hypothesize that a METTL3-m⁶A-p53 axis could be a potential target in HCC therapy.

Autophagy-Related Signatures as Prognostic Indicators for Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) is the most common and deadly type of liver cancer. Autophagy is the process of transporting damaged or aging cellular components into lysosomes for digestion and degradation. Accumulating evidence implies that autophagy is a key factor in tumor progression. The aim of this study was to determine a panel of novel autophagy-related prognostic markers for liver cancer.

Methods

We conducted a comprehensive analysis of autophagy-related gene (ARG) expression profiles and corresponding clinical information based on The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) databases. The univariate Cox proportional regression model was used to screen candidate autophagy-related prognostic genes. In addition, a multivariate Cox proportional regression model was used to identify five key prognostic autophagy-related genes (ATIC, BAX, BIRC5, CAPNS1, and FKBP1A), which were used to construct a prognostic signature. Real-time qPCR analysis was used to evaluate the expression levels of ARGs in 20 surgically resected HCC samples and matched tumor-adjacent normal tissue samples. In addition, the effect of FKBP1A on autophagy and tumor progression was determined by performing in vitro and in vivo experiments.

Results

Based on the prognostic signature, patients with liver cancer were significantly divided into high-risk and low-risk groups in terms of overall survival (OS). A subsequent multivariate Cox regression analysis indicated that the prognostic signature remained an independent prognostic factor for OS. The prognostic signature possessing a better area under the curve (AUC) displayed better performance in predicting the survival of patients with HCC than other clinical parameters. Furthermore, FKBP1A was overexpressed in HCC tissues, and knockdown of FKBP1A impaired cell proliferation, migration, and invasion through the PI3K/AKT/mTOR signaling pathway.

Conclusion

This study provides a prospective biomarker for monitoring outcomes of patients with HCC.

Comprehensive Analysis Identified Mutation-Gene Signature Impacts the Prognosis Through Immune Function in Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) is a life-threatening and refractory malignancy with poor outcome. Genetic mutations are the hallmark of cancer. Thus far, there is no comprehensive prognostic model constructed by mutation-gene transcriptome in HCC. The prognostic value of mutation-gene signature in HCC remains elusive.

Methods

RNA expression profiles and the corresponding clinical information were recruited from The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) databases. The least absolute shrinkage and selection operator (LASSO) Cox regression analysis was employed to establish gene signature. Kaplan–Meier curve and time-dependent receiver operating characteristic curve were implemented to evaluate the prognostic value. The Wilcoxon test was performed to analyze the expression of immune checkpoint genes, cell cycle genes, and tumor drug resistance genes in different risk groups. Finally, quantitative real-time PCR (qRT-RCR) and immunohistochemistry (IHC) were performed to validate the mRNA and protein expression between HCC and adjacent nontumorous tissues in an independent cohort.

Results

A prognostic model consisting of five mutated genes was established by LASSO Cox regression analysis. The prognostic model classified patients into high- and low-risk groups. Compared with the low‐risk group, patients in the high‐risk group had significantly worse survival results. The prognostic model can accurately predict the overall survival of HCC patients and predict overall survival more accurately when combined with stage. Furthermore, the immune checkpoint genes, cell cycle genes, and tumor drug resistance genes were higher expressed in the high-risk group compared in the low-risk group. In addition, the expression level of prognostic signature genes was validated in an independent sample cohort, which was consistent with RNA sequencing expression in the TCGA database.

Conclusion

The prediction model of HCC constructed using mutation-related genes is of great significance for clinical decision making and the personalized treatment of patients with HCC.

The SKA3-DUSP2 Axis Promotes Gastric Cancer Tumorigenesis and Epithelial-Mesenchymal Transition by Activating the MAPK/ERK Pathway

Background: Spindle and kinetochore-related complex subunit 3 (SKA3), a member of the SKA family of proteins, is associated with the progression of multiple cancers. However, the role of SKA3 in gastric cancer has not been studied.

Methods: The expression levels of SKA3 and dual-specificity phosphatase 2 (DUSP2) proteins were detected by immunohistochemistry. The effects of SKA3 and DUSP2 on the proliferation, migration, invasion, adhesion, and epithelial-mesenchymal transition of gastric cancer were studied in vitro and in vivo.

Results: Immunohistochemical analysis of 164 cases of gastric cancer revealed that high expression of SKA3 was negatively correlated with DUSP2 expression and related to N stage, peritoneal metastasis, and poor prognosis. In vitro studies showed that silencing SKA3 expression inhibited the proliferation, migration, invasion, adhesion and epithelial-mesenchymal transition of gastric cancer. In vivo experiments showed that silencing SKA3 inhibited tumor growth and peritoneal metastasis. Mechanistically, SKA3 negative regulates the tumor suppressor DUSP2 and activates the MAPK/ERK pathway to promote gastric cancer.

Conclusion: Our results indicate that the SKA3-DUSP2-ERK1/2 axis is involved in the regulation of gastric cancer progression, and SKA3 is a potential therapeutic target for gastric cancer.

Overexpression of SKA3 correlates with poor prognosis in female early breast cancer

BACKGROUND

Spindle and kinetochore associated complex subunit 3 (SKA3) plays an important role in tumorigenesis and the progression of various tumors. But the relationship between SKA3 and early breast cancer remains unclear. The study aimed to explore the prognostic significance of SKA3 in breast cancer.

METHODS

In the study, SKA3 expression was initially assessed using the Oncomine database and The Cancer Genome Atlas database (TCGA). Then, we presented validation results for RT-qPCR (quantitative reverse transcription PCR) and ELISA (enzyme-linked immunosorbent assay). The relationship between clinical characteristics and SKA3 expression was assessed by Chi-square test and Fisher's exact test. Kaplan-Meier method and Cox regression analysis were conducted to evaluate the prognostic value of SKA3. Gene set enrichment analysis (GSEA) was performed to screen biological pathways using the TCGA dataset. Besides, single sample gene set enrichment analysis (ssGSEA) was utilized to identify immune infiltration cells about SKA3.

RESULTS

SKA3 mRNA was expressed at high levels in breast cancer tissues compared with normal tissues. Chi-square test and Fisher's exact test showed SKA3 expression was related to age, tumor (T) classification, node (N) classification, tumor-node-metastasis (TNM) stage, estrogen receptor (ER), progesterone receptor (PR), molecular subtype, and race. RT-qPCR results showed that SKA3 expression was overexpressed in ER, PR status, and molecular subtype in Chinese people. Kaplan-Meier curves implicated that high SKA3 expression was related to a poor prognosis in female early breast cancer patients. Cox regression models showed that high SKA3 expression could be used as an independent risk factor for female early breast cancer. Four signaling pathways were enriched in the high SKA3 expression group, including mTORC1 signaling pathway, MYC targets v1, mitotic spindle, estrogen response early. Besides, the SKA3 expression level was associate with infiltrating levels of activated CD4 T cells and eosinophils in breast cancer.

CONCLUSION

High SKA3 expression correlates with poor prognosis and immune infiltrates in breast cancer. SKA3 may become a biomarker for the prognosis of breast cancer.

SKA3 Serves as a Biomarker for Poor Prognosis in Kidney Renal Papillary Cell Carcinoma

Background

There is a surprising paucity of studies investigating the potential mechanism of SKA3 in the progression and prognosis of kidney renal papillary cell carcinoma (KIRP).

Methods

We used TCGA and other databases to analyze the expression, clinical value, and potential mechanisms of SKA3 in KIRP patients. We also explored therapeutic agents for KIRP through GSCALite.

Results

SKA3 mRNA expression was significantly upregulated and the area under the curve was 0.792 (95% CI 0.727–0.856). Increased SKA3 expression was related to shorter overall survival, disease-specific survival and progression-free survival. Hub genes in protein–protein interactions were CDK1, CDC20, CCNB1, CCNA2, BUB1, AURKB, BUB1B, PLK1, CCNB2, and MAD2L1, which were differentially expressed and also associated with KIRP prognosis. Gene-set enrichment analysis indicated that E2F targets, epithelial–mesenchymal transition, glycolysis, the WNT signaling pathway, and other pathways were highly enriched upon SKA3 upregulation. Gene-set variation analysis of SKA3 and its ten hub genes showed that the significant correlation of cancer-related pathways included the cell cycle, DNA damage, hormone androgen receptor, hormone estrogen receptor, PI3K/Akt, and Ras/MAPK. In addition, we found that MEK inhibitors, ie, trametinib, selumetinib, PD0325901, and RDEA119, may be feasible targeting agents for KIRP patients.

Conclusion

SKA3 might contribute to poor prognosis of KIRP through cell cycle, DNA damage, hormone androgen receptor, hormone estrogen receptor, PI3K/Akt, and RAS/MAPK. SKA3 potentially serves as a prognostic biomarker and target for KIRP.

Integrative analysis of prognostic value and immune infiltration of spindle and kinetochore-associated family members in breast cancer

Spindle and kinetochore associated (SKA) complex subunit, which maintains the stability of mitotic metaphase, with emerging research implying its effect as a carcinogenic regulator in cancer. However, its potential role in BC has not been fully elucidated. ONCOMINE, UALCAN, GEPIA, Kaplan-Meier Plotter, cBioPortal and TIMER databases were performed to analyze the expression, prognosis, mutation, immune infiltration and potential biological mechanisms of SKA1/2/3 in BC. Our results showed that SKA1/2/3 expression was upregulated in BC. Survival analysis reveals that SKA3 overexpression was associated with poor overall survival (OS), relapse-free survival (RFS), post-progression survival (PPS) and distant metastasis-free survival (DMFS). SKA1 overexpression was associated with poor OS, RFS and DMFS while SKA2 overexpression was only associated with RFS and DMFS. Notably, the results implied that SKA1 has a good prognostic value in HER2-positive BC. Besides, the genetic alterations of SKA were investigated and the altered group correlated with shorter progress-free survival (PFS) and disease-specific survival (DSS). GO and KEGG analysis showed that SKA1/2/3 were implicated in regulating cell cycle, p53 signaling pathway and DNA replication. The 10 Hub genes in the protein network were upregulated in BC and related to poorer prognosis. Additionally, SKA1/2/3 expression was negatively correlated with infiltration of various immune cells with antitumor effects, whereas positively correlated with the expression of immune checkpoints molecules. Further experiments revealed that SKA1/2/3 silencing markedly impeded the proliferation and migration of BC cells. Herein, our study firmly shows that SKA genes may serve as a promising therapeutic target for patients with BC.

HNRNPU promotes the progression of hepatocellular carcinoma by enhancing CDK2 transcription

The nuclear matrix-associated protein Heterogeneous Nuclear Ribonucleoprotein U (HNRNPU), also known as SAF-A, is known to maintain active chromatin structure in mouse hepatocytes. However, the functional roles and molecular mechanisms of HNRNPU in the development of hepatocellular carcinoma (HCC) remain largely unknown. Herein, we found that HNRNPU was upregulated in HCC, and the proliferation of HCC cells was inhibited in vitro and in vivo upon HNRNPU knockdown. Moreover, the upregulation of HNRNPU was correlated with poor prognosis in HCC. Mechanistically, HNRNPU bound to the CDK2 gene locus, a key factor in cell cycle regulation, where it was enriched with H3K27 acetylation (H3K27ac), H3K9 acetylation (H3K9ac), and H3K4 mono-methylation (H3K4me1). Furthermore, HNRNPU knockdown reduced the levels of H3K27ac and H3K9ac at the binding site, where the levels of H3K27 tri-methylation (H3K27me3) were increased, eventually leading to the downregulation of CDK2. Collectively, our results provide a new mechanism whereby HNRNPU promotes HCC development by enhancing the transcription of CDK2.

Construction of a circular RNA-microRNA-messenger RNA regulatory network of hsa_circ_0043256 in lung cancer by integrated analysis

BACKGROUND

Patients with non-small cell lung cancer (NSCLC) are diagnosed in advanced stages and with a poor 5-year survival rate. There is a critical need to identify novel biomarkers to improve the therapy and overall prognosis of this disease.

METHODS

Differentially expressed genes (DEGs) were identified from three profiles of GSE101586, GSE101684 and GSE112214 using Venn diagrams. hsa_circ_0043256 were validated using quantitative real-time polymerase chain reaction (RT-qPCR). The circular RNA-microRNA-messenger RNA (circRNA-miRNA-mRNA) regulatory network was constructed with Cytoscape 3.7.0. Hub genes were identified with protein interaction (PPI) and validated with the Gene Expression Profiling Interactive Analysis (GEPIA), Human Protein Atlas (HPA) databases, and immunohistochemistry. Survival analyses were also performed using a Kaplan-Meier (KM) plotter. The effects of hsa_circ_0043256 on cell proliferation and cell cycles were evaluated by EdU staining and flow cytometry, respectively.

RESULTS

hsa_circ_0043256, hsa_circ_0029426 and hsa_circ_0049271 were obtained. Following RT-qPCR validation, hsa_circ_0043256 was selected for further analysis. In addition, functional experiment results indicated that hsa_circ_0043256 could inhibit cell proliferation and cell-cycle progression of NSCLC cells in vitro. Prediction by three online databases and combining with DEGs identified from The Cancer Genome Atlas (TCGA), a network containing one circRNAs, three miRNAs, and 209 mRNAs was developed. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated DEGs might be associated with lung cancer onset and progression. A PPI network based on the 209 genes was established, and five hub genes (BIRC5, SHCBP1, CCNA2, SKA3, and GINS1) were determined. Following verification of five hub genes using GEPIA database, HPA database, and immunohistochemistry. High expression of all five hub genes led to poor overall survival.

CONCLUSION

Our study constructed a circRNA-miRNA-mRNA network of hsa_circ_0043256. hsa_circ_0043256 may be a potential therapeutic target for lung cancer.

A network pharmacology approach to investigate the anticancer mechanism of cinobufagin against hepatocellular carcinoma via downregulation of EGFR-CDK2 signaling

Hepatocellular carcinoma (HCC) is one of the deadliest cancers with high mortality and poor prognosis, and the investigation on new approaches and effective drugs for HCC therapy is of great significance. In our study, we demonstrate that treatment with cinobufagin, a natural compound isolated from traditional chinese medicine Chansu, reduces proliferation and the colony formation capacity of the human hepatoma cells in vitro, in addition, cinobufagin induces mitotic arrest in human hepatoma cells. The results of a network pharmacology-based analysis show that EGFR, MAPK1, PTK2, CDK2, MAPK3, ESR1, CDK1, PRKCA, AR, and CSNK2A1 are the key targets involved in the anti-tumor activities of cinobufagin, additionally, several signaling pathways such as proteoglycans in cancer, pathways in cancer, HIF-1 signaling pathway, VEGF signaling pathway, ErbB signaling pathway, and PI3K-AKT signaling pathway are identified as the potential pathways involved in the inhibitory effects of cinobufagin against HCC. Furthermore, at the molecular level, we find that cinobufagin decreases EGFR expression and CDK2 activity in human hepatoma cells. Inhibition of EGFR or CDK2 expression could not only suppress the growth of tumor cells but also enhance the inhibitory effects of cinobufagin on the proliferative potential of human hepatoma cells. We also demonstrate that EGFR positively regulates CDK2 expression. Furthermore, EGFR inhibitor gefitinib or CDK2 inhibitor CVT-313 synergistically enhances anticancer effects of cinobufagin in human hepatoma cells. Taken together, these findings indicate that cinobufagin may exert antitumor effects by suppressing EGFR-CDK2 signaling, and our study suggests that cinobufagin may be a novel, promising anticancer agent for the treatment of HCC.

Downregulation of Cx43 reduces cisplatin-induced acute renal injury by inhibiting ferroptosis

Ferroptosis is one of the main mechanisms involved in different forms of acute kidney injury (AKI), including cisplatin-induced AKI. However, it is not clear whether Cx43 has a regulatory effect on ferroptosis caused by cisplatin. In this study, we investigate the regulatory effects of Cx43 on cisplatin-induced ferroptosis and its mechanism. In vivo and in vitro studies showed that the expression level of Cx43 was significantly upregulated in the cisplatin-induced kidney injury model. In HK2 cells, cisplatin significantly induced ferroptosis. Adding shRNA-Cx43 and gap27 to the HK2 cells downregulated the expression of Cx43 and blocked the effects of cisplatin, resulting in a significantly improved survival rate of HK2 cells. Our primary data suggested that downregulating Cx43 not only inhibits ferroptosis, but also inhibits apoptosis. Through mechanistic studies, we confirmed that downregulating the expression of Cx43 by increasing SLC7A11 can increase the GSH content to inhibit cisplatin-induced ferroptosis. In vivo experiments showed that downregulation of Cx43 expression by gap27 reduced AKI in the animal model by inhibiting cisplatin-induced ferroptosis. Therefore, our results indicated that downregulation of Cx43 can inhibit ferroptosis by restoring the level of SLC7A11 in the system x_c‾ transporter and alleviate cisplatin-induced AKI.

Spindle and kinetochore-associated complex subunit 3 (SKA3) promotes stem cell-like properties of hepatocellular carcinoma cells through activating Notch signaling pathway

Background

Cancer stemness contributes to hepatocellular carcinoma (HCC) initiation, metastasis, drug resistance, and recurrence. The spindle and kinetochore-associated (SKA) complex has been shown to be involved in tumor progression; however, its effects on cancer stem cell-like properties have not yet been examined. This research sought to study each subunit of the SKA complex in HCC systematically.

Methods

Bioinformatic analyses were carried out to examine the expression and clinical data of the SKA complex’s each subunit in HCC. The expression of the target genes was detected by quantitative reverse transcription-polymerase chain reaction and Western blot assays. Clone formation and Transwell assays were performed to assess the proliferation and migration abilities of the SKA complex’s each subunit. Sphere formation assays and subcutaneous xenograft experiments were performed to investigate the effects of SKA complex subunit 3 (SKA3) on the self-renewal and tumorigenic abilities of HCC.

Results

Each subunit of the SKA complex was highly expressed in HCC, but only SKA complex subunit 1 (SKA1) and SKA3 were associated with the poor overall survival of HCC patients. Additionally, the HCC cells overexpressing SKA3 exhibited increased migration, invasion, proliferation, self-renewal, Sorafenib resistance and tumorigenic abilities. Notch signaling played a vital role in the process by which SKA3 promoted HCC stemness.

Conclusions

SKA3 promotes HCC stem cell-like properties via the Notch signaling pathway. As SKA3 appears to act as a regulator of stemness in HCC, it might be a potential molecular target for HCC.

Inhibition of spindle and kinetochore associated complex subunit 3 suppresses the proliferation and invasion and induced the apoptosis of cutaneous melanoma by affecting the PI3K/Akt pathway

Spindle and kinetochore-associated complex subunit 3 (SKA3) is reportedly a key contributor to the progression of various cancers. The present work aimed to evaluate the possible role of SKA3 in cutaneous melanoma (CM). A high SKA3 level was found in CM tissues and predicted a poor prognosis. SKA3 silencing markedly repressed the proliferation, invasion, and epithelial-mesenchymal transition and induced the apoptosis of CM cells. SKA3 silencing decreased the phosphorylation of PI3K and Akt. Akt inhibition markedly reversed SKA3 overexpression-induced oncogenic effects on CM cells. SKA3 silencing significantly prohibited the formation and growth of CM-derived xenograft tumors in nude mice in vivo. Our findings demonstrated SKA3 inhibition repressed the progression of CM by downregulating the PI3K/Akt pathway. This study indicates that SKA3 has potential as an anticancer candidate for CM.

SKA3 overexpression predicts poor outcomes in skin cutaneous melanoma patients

BACKGROUND

Spindle and Kinetochore Associated Complex Subunit 3 (SKA3) is a part of the SKA complex, which plays a key role in cell mitosis. Studies have shown that SKA3 was associated with cancer progression. However, its role in skin cutaneous melanoma (SKCM) remains unclear. Here, we investigated the expression level and prognostic value of SKA3 in SKCM.

METHODS

Based on public databases, univariate and multivariate Cox regression analyses were used to investigate the different expression of SKA3 between SKCM and normal tissues. Then, the relationship between SKA3 expression level and prognosis was assessed. PPI network and functional enrichment analysis were performed. ESTIMATE and CIBERSORT were expected to evaluate the SKA3 expression and immune status. CCK8, wound healing, transwell assays and tumor xenograft trial were performed to detect the SKA3 function in cell viability, migration and invasion of the cell lines.

RESULTS

The SKA3 was highly expressed in SKCM tissues. SKA3 overexpression was associated with poor survival and immune status. SKA3 knockdown inhibited cell viability, migration and invasion of SKCM cells.

CONCLUSION

SKA3 is involved in the progression of SKCM and may serve as a new prognostic biomarker and therapeutic target.

miR-1207-5p suppresses laryngeal squamous cell carcinoma progression by downregulating SKA3 and inhibiting epithelial-mesenchymal transition

Laryngeal squamous cell carcinoma (LSCC) is the second most common head and neck cancer. Previously, we discovered that miR-1207-5p was downregulated in LSCC. In this study, the clinical significance, function, and mechanism of miR-1207-5p in LSCC were investigated. Downregulation of miR-1207-5p was found to be strongly linked to the malignant progression of LSCC. Functional studies revealed that miR-1207-5p upregulation suppressed LSCC cell proliferation, invasion, migration, and xenograft tumor growth. Bioinformatics analysis revealed that miR-1207-5p target genes were involved in cell cycle regulation, proliferation, adhesion, and the phosphatidylinositol 3-kinase (PI3K)/Akt pathway. Mechanistic studies revealed that miR-1207-5p interacts directly with the 3′ untranslated region of spindle and kinetochore associated complex subunit 3 (SKA3) and downregulates SKA3 expression. Furthermore, SKA3 was found to be overexpressed in LSCC, and its high expression was associated with tumor progression and a poor prognosis. Rescue experiments demonstrated that miR-1207-5p inhibited the malignant phenotypes of LSCC via SKA3. Furthermore, miR-1207-5p upregulation or knockdown of SKA3 inhibited the epithelial-mesenchymal transition (EMT). Collectively, miR-1207-5p inhibited LSCC malignant progression by downregulating SKA3 and preventing EMT. These findings provide new insights into the mechanism of LSCC progression, as well as new potential biomarkers and therapeutic targets for LSCC diagnosis and treatment.

Integrative Transcriptome Profiling Reveals SKA3 as a Novel Prognostic Marker in Non-Muscle Invasive Bladder Cancer

Approximately 80% of all new bladder cancer patients are diagnosed with non-muscle invasive bladder cancer (NMIBC). However, approximately 15% of them progress to muscle-invasive bladder cancer (MIBC), for which prognosis is poor. The current study aimed to improve diagnostic accuracy associated with clinical outcomes in NMIBC patients. Nevertheless, it has been challenging to identify molecular biomarkers that accurately predict MIBC progression because this disease is complex and heterogeneous. Through integrative transcriptome profiling, we showed that high SKA3 expression is associated with poor clinical outcomes and MIBC progression. We performed RNA sequencing on human tumor tissues to identify candidate biomarkers in NMIBC. We then selected genes with prognostic significance by analyzing public datasets from multiple cohorts of bladder cancer patients. We found that SKA3 was associated with NMIBC pathophysiology and poor survival. We analyzed public single-cell RNA-sequencing (scRNA-seq) data for bladder cancer to dissect transcriptional tumor heterogeneity. SKA3 was expressed in an epithelial cell subpopulation expressing genes regulating the cell cycle. Knockdown experiments confirmed that SKA3 promotes bladder cancer cell proliferation by accelerating G2/M transition. Hence, SKA3 is a new prognostic marker for predicting NMIBC progression. Its inhibition could form part of a novel treatment lowering the probability of bladder cancer progression.

SKA3, negatively regulated by miR-128-3p, promotes the progression of non-small-cell lung cancer

Aim: To investigate the effects of SKA3 on cell proliferation and metastasis in non-small-cell lung cancer (NSCLC) and its underlying mechanism. Methods: Immunohistochemistry was employed to analyze the expression of SKA3 in NSCLC. CCK-8 assay, EdU assay, Transwell assay and flow cytometry analysis were employed to assess cell proliferation, metastatic potential and apoptosis in vitro, respectively. A lung metastasis model was used to evaluate metastasis of NSCLC cells in vivo. A luciferase reporter gene assay was conducted to verify the targeting relationship. Results: SKA3 exhibited high expression in NSCLC tissues and cells. Overexpression of SKA3 remarkably accelerated cell proliferation and metastasis and suppressed apoptosis of NSCLC cells and promoted lung metastasis in a mouse model. miR-128-3p repressed SKA3 expression by targeting it. Conclusion: miR-128-3p inhibited the progression of NSCLC through targeting SKA3.

SMG9 Serves as an Oncogene to Promote the Tumor Progression via EMT and Wnt/β-Catenin Signaling Pathway in Hepatocellular Carcinoma

Background/Aims: SMG9 participates in the nonsense-mediated mRNA decay process that degrades mRNA harboring nonsense mutations introduced either at the level of transcription or RNA processing. However, little is known about the role of SMG9 in hepatocellular carcinoma (HCC). The objective of this research was to clarify the effects of SMG9 expression on HCC progression.

Methods: Microarray data were acquired from NCBI Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) database to bioinformatically analyze the differential expression of SMG9 between HCC patients and normal controls. SMG9 mRNA level was measured in sixteen sets of fresh tumor tissues and adjacent non-cancerous liver tissues (ANLTs) via reverse transcription-quantitative polymerase chain reaction (RT-qPCR). SMG9 protein expression was analyzed in ninety-five sets of paired formalin-fixed and paraffin-embedded tissue specimens by immunohistochemistry (IHC). In addition, clinicopathological features of SMG9 in HCC were checked. For in vitro studies, small interfering RNA (siRNA) was used to silence SMG9 expression for exploring biological functions and underlying mechanisms of SMG9 in SMMC-7721 and HepG2.

Results: We found that SMG9 was upregulated in HCC tissues and SMG9 levels were closely related to TNM stage, tumor number and tumor size. Cox regression and Kaplan–Meier proportional hazards analyses showed that high expression of SMG9 was associated with poor patient survival. Furthermore, proliferation, apoptosis resistance, migration and invasion of both SMMC-7721 and HepG2 cells were suppressed by SMG9 inhibition. In addition, EMT and the Wnt/β-catenin signaling pathway were involved in SMG9-mediated HCC progression.

Conclusions: SMG9 may serve as a potential novel prognostic biomarker and therapeutic target in HCC patients.

Identification of CDK2-Related Immune Forecast Model and ceRNA in Lung Adenocarcinoma, a Pan-Cancer Analysis

Background

Tumor microenvironment (TME) plays important roles in different cancers. Our study aimed to identify molecules with significant prognostic values and construct a relevant Nomogram, immune model, competing endogenous RNA (ceRNA) in lung adenocarcinoma (LUAD).

Methods

“GEO2R,” “limma” R packages were used to identify all differentially expressed mRNAs from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. Genes with P-value <0.01, LogFC>2 or <-2 were included for further analyses. The function analysis of 250 overlapping mRNAs was shown by DAVID and Metascape software. By UALCAN, Oncomine and R packages, we explored the expression levels, survival analyses of CDK2 in 33 cancers. “Survival,” “survminer,” “rms” R packages were used to construct a Nomogram model of age, gender, stage, T, M, N. Univariate and multivariate Cox regression were used to establish prognosis-related immune forecast model in LUAD. CeRNA network was constructed by various online databases. The Genomics of Drug Sensitivity in Cancer (GDSC) database was used to explore correlations between CDK2 expression and IC50 of anti-tumor drugs.

Results

A total of 250 differentially expressed genes (DEGs) were identified to participate in many cancer-related pathways, such as activation of immune response, cell adhesion, migration, P13K-AKT signaling pathway. The target molecule CDK2 had prognostic value for the survival of patients in LUAD (P = 5.8e-15). Through Oncomine, TIMER, UALCAN, PrognoScan databases, the expression level of CDK2 in LUAD was higher than normal tissues. Pan-cancer analysis revealed that the expression, stage and survival of CDK2 in 33 cancers, which were statistically significant. Through TISIDB database, we selected 13 immunodepressants, 21 immunostimulants associated with CDK2 and explored 48 genes related to these 34 immunomodulators in cBioProtal database (P < 0.05). Gene Set Enrichment Analysis (GSEA) and Metascape indicated that 49 mRNAs were involved in PUJANA ATM PCC NETWORK (ES = 0.557, P = 0, FDR = 0), SIGNAL TRANSDUCTION (ES = –0.459, P = 0, FDR = 0), immune system process, cell proliferation. Forest map and Nomogram model showed the prognosis of patients with LUAD (Log-Rank = 1.399e-08, Concordance Index = 0.7). Cox regression showed that four mRNAs (SIT1, SNAI3, ASB2, and CDK2) were used to construct the forecast model to predict the prognosis of patients (P < 0.05). LUAD patients were divided into two different risk groups (low and high) had a statistical significance (P = 6.223e-04). By “survival ROC” R package, the total risk score of this prognostic model was AUC = 0.729 (SIT1 = 0.484, SNAI3 = 0.485, ASB2 = 0.267, CDK2 = 0.579). CytoHubba selected ceRNA mechanism medicated by potential biomarkers, 6 lncRNAs-7miRNAs-CDK2. The expression of CDK2 was associated with IC50 of 89 antitumor drugs, and we showed the top 20 drugs with P < 0.05.

Conclusion

In conclusion, our study identified CDK2 related immune forecast model, Nomogram model, forest map, ceRNA network, IC50 of anti-tumor drugs, to predict the prognosis and guide targeted therapy for LUAD patients.

Transcript levels of spindle and kinetochore-associated complex 1/3 as prognostic biomarkers correlated with immune infiltrates in hepatocellular carcinoma

The spindle and kinetochore-associated protein complex (Ska) is an essential component in chromosome segregation. It comprises three proteins (Ska1, Ska2, and Ska3) with theorized roles in chromosomal instability and tumor development, and its overexpression has been widely reported in a variety of tumors. However, the prognostic significance and immune infiltration of Ska proteins in hepatocellular carcinoma (HCC) are not completely understood. The bioinformatics tools Oncomine, UALCAN, gene expression profiling interactive analysis 2 (GEPIA2), cBioPortal, GeneMANIA, Metascape, and TIMER were used to analyze differential expression, prognostic value, genetic alteration, and immune cell infiltration of the Ska protein complex in HCC patients. We found that the mRNA expression of the Ska complex was markedly upregulated in HCC. High expression of the Ska complex is closely correlated with tumor stage, patient race, tumor grade, and TP53 mutation status. In addition, high expression of the Ska complex was significantly correlated with poor disease-free survival, while the high expression levels of Ska1 and Ska3 were associated with shorter overall survival. The biological functions of the Ska complex in HCC primarily involve the amplification of signals from kinetochores, the mitotic spindle, and (via a MAD2 invasive signal) unattached kinetochores. Furthermore, the expression of the complex was positively correlated with tumor-infiltrating cells. These results may provide new insights into the development of immunotherapeutic targets and prognostic biomarkers for HCC.

SKA3 promotes glioblastoma proliferation and invasion by enhancing the activation of Wnt/β-catenin signaling via modulation of the Akt/GSK-3β axis

Spindle and kinetochore-related complex subunit 3 (SKA3) is a key modulator of the progression of multiple tumor types. However, the involvement of SKA3 in glioblastoma (GBM) has not been well studied. The current study aimed to explore the role of SKA3 expression and the potential function of the protein in GBM. Our data showed that SKA3 expression was significantly up-regulated in GBM. Functional assays demonstrated that the knockdown of SKA3 impeded the proliferation, colony formation and invasion of GBM cells, while SKA3 overexpression produced the opposite effects. Further investigation revealed that SKA3 overexpression enhanced the activation of Wnt/β-catenin signaling, which was associated with the enhanced phosphorylation of Akt and glycogen synthase kinase-3β (GSK-3β). Notably, the inhibition of Akt markedly abrogated the SKA3 overexpression-induced promotion of Wnt/β-catenin signaling in GBM cells. Further, the inhibition of Wnt/β-catenin signaling markedly abrogated the SKA3 overexpression-induced promotion of tumor growth. In addition, the knockdown of SKA3 significantly retarded tumor formation and GBM progression in vivo. In summary, these data demonstrate that SKA3 exerts promotes tumor growth in GBM by enhancing the activation of Wnt/β-catenin signaling via modulation of the Akt/GSK-3β axis. This work highlights the pivotal role of SKA3/Akt/GSK-3β/Wnt/β-catenin signaling in the progression of GBM and suggests that SKA3 is an attractive therapeutic target with potential to be used to treat GBM.

A prognostic model for hepatocellular carcinoma based on apoptosis-related genes

Background

Dysregulation of the balance between proliferation and apoptosis is the basis for human hepatocarcinogenesis. In many malignant tumors, such as hepatocellular carcinoma (HCC), there is a correlation between apoptotic dysregulation and poor prognosis. However, the prognostic values of apoptosis-related genes (ARGs) in HCC have not been elucidated.

Methods

To screen for differentially expressed ARGs, the expression levels of 161 ARGs from The Cancer Genome Atlas (TCGA) database (https://cancergenome.nih.gov/) were analyzed. Gene Ontology (GO) enrichment and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to evaluate the underlying molecular mechanisms of differentially expressed ARGs in HCC. The prognostic values of ARGs were established using Cox regression, and subsequently, a prognostic risk model for scoring patients was developed. Kaplan–Meier (K-M) and receiver operating characteristic (ROC) curves were plotted to determine the prognostic value of the model.

Results

Compared with normal tissues, 43 highly upregulated and 8 downregulated ARGs in HCC tissues were screened. GO analysis results revealed that these 51 genes are indeed related to the apoptosis function. KEGG analysis revealed that these 51 genes were correlated with MAPK, P53, TNF, and PI3K-AKT signaling pathways, while Cox regression revealed that 5 ARGs (PPP2R5B, SQSTM1, TOP2A, BMF, and LGALS3) were associated with prognosis and were, therefore, obtained to develop the prognostic model. Based on the median risk scores, patients were categorized into high-risk and low-risk groups. Patients in the low-risk groups exhibited significantly elevated 2-year or 5-year survival probabilities (p < 0.0001). The risk model had a better clinical potency than the other clinical characteristics, with the area under the ROC curve (AUC = 0.741). The prognosis of HCC patients was established from a plotted nomogram.

Conclusion

Based on the differential expression of ARGs, we established a novel risk model for predicting HCC prognosis. This model can also be used to inform the individualized treatment of HCC patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02175-9.

Expression and Prognostic Characteristics of m6A RNA Methylation Regulators in Colon Cancer

Colon cancer is a common and leading cause of death and malignancy worldwide. N6-methylation of adenosine (m6A) is the most common reversible mRNA modification in eukaryotes, and it plays a crucial role in various biological functions in vivo. Dysregulated expression and genetic changes of m6A regulators have been correlated with tumorigenesis, cancer cell proliferation, tumor microenvironment, and prognosis in cancers. This study used RNA-seq and colon cancer clinical data to explore the relationship between N6-methylation and colon cancer. Based on the seven m6A regulators related to prognosis, three molecular subgroups of colon cancer were identified. Surprisingly, we found that each subgroup had unique survival characteristics. We then identified three subtypes of tumors based on 299 m6A phenotype-related genes, and one subtype was characterized as an immunosuppressive tumor and patients in this subtype may be more suitable for immunotherapy than other subtypes. Finally, using m6A-related genes and clinical information from The Cancer Genome Atlas cohort, we constructed a prognosis model, and this model could be used to predict the prognosis of patients in clinics.

Spindle and kinetochore‑associated complex subunit 3 accelerates breast cancer cell proliferation and invasion through the regulation of Akt/Wnt/β-catenin signaling

PURPOSE

Spindle and kinetochore‑associated complex subunit 3 (SKA3) has recently been identified as a novel regulator of carcinogenesis in multiple types of cancers. However, the function and potential regulatory mechanisms of SKA3 in breast cancer remain poorly understood. The present study was designed to gain a detailed relevance of SKA3 in breast cancer.

METHODS

Expression of SKA3 in breast cancer was examined via real-time quantitative PCR, western blotting and immunohistochemistry analysis. Malignant behaviors of breast cancer cells were investigated via cell counting kit-8, cell apoptosis, and transwell invasion assays. The activity of Wnt/β-catenin signaling was monitored via luciferase reporter assay. The tumorigenicity of breast cancer cells in vivo was assessed via xenograft tumor assay.

RESULTS

SKA3 expression was elevated in breast cancer tissue and was correlated with shorter survival rates in breast cancer patients. Knockdown of SKA3 caused marked reductions in cellular proliferation and invasion in breast cancer cells, whereas SKA3 overexpression accelerated proliferation and invasion. Knockdown of SKA3 resulted in decreased Akt and glycogen synthase kinase-3β phosphorylation, and decreased expression of active β-catenin, which lead to the inactivation of Wnt/β-catenin signaling. Inhibition of Akt significantly reversed the SKA3 overexpression-induced activation of Wnt/β-catenin signaling. Inhibition of Wnt/β-catenin signaling markedly abrogated SKA3 overexpression-induced tumor-promotion effects, while re-activation of Wnt/β-catenin signaling significantly reversed SKA3 knockdown-mediated tumor-inhibition effects. Knockdown of SKA3 resulted in a significant decrease in breast cancer tumor formation in vivo.

CONCLUSIONS

SKA3 accelerates proliferation and invasion in breast cancer through the modulation of Akt/Wnt/β-catenin signaling.

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.