Aberrant expression of KPNA2 is associated with a poor prognosis and contributes to OCT4 nuclear transportation in bladder cancer

Tumor-derived exosomal KPNA2 activates fibroblasts and interacts with KIFC1 to promote bladder cancer progression, a process inhibited by miR-26b-5p

BACKGROUND

Recent studies have illuminated the complexities of treating advanced bladder cancer (BCa), underscoring the importance of comprehending its molecular mechanisms for creating novel therapies. While the role of Karyopherin a2 (KPNA2) in promoting BCa growth is established, the precise mechanism remains elusive.

METHODS

To investigate the regulatory role of KPNA2 in BCa, we employed a comprehensive approach integrating clinical case data and bioinformatics analysis to evaluate the expression of KPNA2 in BCa tissues. Mechanisms promoting cancer by KPNA2 were examined using both in vivo and in vitro models.

RESULTS

Our research reveals that miR-26b-5p acts as an anticancer factor by targeting and inhibiting KPNA2 expression. Furthermore, we have observed that the interaction between KPNA2 and Kinesin Family Member C1 (KIFC1) facilitates the transition of BCa cells into the G2/M phase, thereby promoting tumor advancement via activation of the Phosphoinositide 3-kinase (PI3K)- Protein Kinase B (AKT) pathway. Importantly, this investigation is the first to identify KPNA2 expression in exosomes originating from BCa tissues. Plasma exosomes from patients with BCa exhibited notably increased levels of KPNA2 compared with healthy controls, suggesting KPNA2 as a potential new tumor indicator. Additionally, KPNA2 from BCa cells triggered the conversion of fibroblasts into cancer-associated fibroblasts (CAFs), which secreted elevated levels of interleukin-6 (IL-6), contributing to a tumor-supporting environment.

CONCLUSIONS

These findings suggest that KPNA2 is a key gene that promotes BCa progression, can potentially be a novel tumor marker, and may serve as a new therapeutic target for BCa.

Homeobox Gene Expression Dysregulation as Potential Diagnostic and Prognostic Biomarkers in Bladder Cancer

Homeobox genes serve as master regulatory transcription factors that regulate gene expression during embryogenesis. A homeobox gene may have either tumor-promoting or tumor-suppressive properties depending on the specific organ or cell lineage where it is expressed. The dysregulation of homeobox genes has been reported in various human cancers, including bladder cancer. The dysregulated expression of homeobox genes has been associated with bladder cancer clinical outcomes. Although bladder cancer has high risk of tumor recurrence and progression, it is highly challenging for clinicians to accurately predict the risk of tumor recurrence and progression at the initial point of diagnosis. Cystoscopy is the routine surveillance method used to detect tumor recurrence. However, the procedure causes significant discomfort and pain that results in poor surveillance follow-up amongst patients. Therefore, the development of reliable non-invasive biomarkers for the early detection and monitoring of bladder cancer is crucial. This review provides a comprehensive overview of the diagnostic and prognostic potential of homeobox gene expression dysregulation in bladder cancer.

Long noncoding RNA TUG1 decreases bladder cancer chemo-sensitivity toward doxorubicin through elevating KPNA2 expression and activating the PI3K/AKT pathway via adsorbing miR-582-5p

Long noncoding RNA taurine-upregulated gene1 (TUG1) has been reported to be implicated in the chemo-resistance of bladder cancer. Hence, this study aimed to survey regulatory mechanism by which TUG1 regulates the chemo-resistance of bladder cancer cells to doxorubicin (DOX). Relative expression of TUG1, miR-582-5p, and karyopherin alpha 2 (KPNA2) was detected by qRT-PCR. The viability and proliferation of DOX-resistant bladder cancer cells were determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Protein levels were measured by western blot analysis. The apoptosis, migration, and invasion of DOX-resistant bladder cancer cells were determined by flow cytometry or transwell assays. The relationship between TUG1 or KPNA2 and miR-582-5p was verified by dual-luciferase reporter assay. TUG1 and KPNA2 were upregulated while miR-582-5p was downregulated in resistant bladder cancer tissues and cells. TUG1 inhibition elevated cell chemo-sensitivity, facilitated cell apoptosis, and curbed proliferation, migration, invasion, and autophagy of DOX-resistant bladder cancer cells. Also, TUG1 acted as a sponge for miR-582-5p, and miR-582-5p inhibitor reversed TUG1 knockdown-mediated influence on DOX chemo-sensitivity and malignant behaviors in DOX-resistant bladder cancer cells. Furthermore, miR-582-5p targeted KPNA2, and KPNA2 overexpression counteracted the inhibitory impact of miR-582-5p mimic on DOX chemo-resistance and malignant behaviors in DOX-resistant bladder cancer cells. Additionally, TUG1 silencing inactivated the PI3K/AKT pathway through sponging miR-582-5p. TUG1 sponged miR-582-5p to increase KPNA2 expression and activated the KPNA2/PI3K/AKT pathway, thereby elevating DOX chemo-resistance and malignant behaviors in bladder cancer cells.

A mass spectrometry-based approach for the identification of Kpnβ1 binding partners in cancer cells

Karyopherin beta 1 (Kpnβ1) is the principal nuclear importer of cargo proteins and plays a role in many cellular processes. Its expression is upregulated in cancer and essential for cancer cell viability, thus the identification of its binding partners might help in the discovery of anti-cancer therapeutic targets and cancer biomarkers. Herein, we applied immunoprecipitation coupled to mass spectrometry (IP-MS) to identify Kpnβ1 binding partners in normal and cancer cells. IP-MS identified 100 potential Kpnβ1 binding partners in non-cancer hTERT-RPE1, 179 in HeLa cervical cancer, 147 in WHCO5 oesophageal cancer and 176 in KYSE30 oesophageal cancer cells, including expected and novel interaction partners. 38 binding proteins were identified in all cell lines, with the majority involved in RNA metabolism. 18 binding proteins were unique to the cancer cells, with many involved in protein translation. Western blot analysis validated the interaction of known and novel binding partners with Kpnβ1 and revealed enriched interactions between Kpnβ1 and select proteins in cancer cells, including proteins involved in cancer development, such as Kpnα2, Ran, CRM1, CCAR1 and FUBP1. Together, this study shows that Kpnβ1 interacts with numerous proteins, and its enhanced interaction with certain proteins in cancer cells likely contributes to the cancer state.

Polygenic risk modeling of tumor stage and survival in bladder cancer

Introduction

Bladder cancer assessment with non-invasive gene expression signatures facilitates the detection of patients at risk and surveillance of their status, bypassing the discomforts given by cystoscopy. To achieve accurate cancer estimation, analysis pipelines for gene expression data (GED) may integrate a sequence of several machine learning and bio-statistical techniques to model complex characteristics of pathological patterns.

Methods

Numerical experiments tested the combination of GED preprocessing by discretization with tree ensemble embeddings and nonlinear dimensionality reductions to categorize oncological patients comprehensively. Modeling aimed to identify tumor stage and distinguish survival outcomes in two situations: complete and partial data embedding. This latter experimental condition simulates the addition of new patients to an existing model for rapid monitoring of disease progression. Machine learning procedures were employed to identify the most relevant genes involved in patient prognosis and test the performance of preprocessed GED compared to untransformed data in predicting patient conditions.

Results

Data embedding paired with dimensionality reduction produced prognostic maps with well-defined clusters of patients, suitable for medical decision support. A second experiment simulated the addition of new patients to an existing model (partial data embedding): Uniform Manifold Approximation and Projection (UMAP) methodology with uniform data discretization led to better outcomes than other analyzed pipelines. Further exploration of parameter space for UMAP and t-distributed stochastic neighbor embedding (t-SNE) underlined the importance of tuning a higher number of parameters for UMAP rather than t-SNE. Moreover, two different machine learning experiments identified a group of genes valuable for partitioning patients (gene relevance analysis) and showed the higher precision obtained by preprocessed data in predicting tumor outcomes for cancer stage and survival rate (six classes prediction).

Conclusions

The present investigation proposed new analysis pipelines for disease outcome modeling from bladder cancer-related biomarkers. Complete and partial data embedding experiments suggested that pipelines employing UMAP had a more accurate predictive ability, supporting the recent literature trends on this methodology. However, it was also found that several UMAP parameters influence experimental results, therefore deriving a recommendation for researchers to pay attention to this aspect of the UMAP technique. Machine learning procedures further demonstrated the effectiveness of the proposed preprocessing in predicting patients’ conditions and determined a sub-group of biomarkers significant for forecasting bladder cancer prognosis.

SMARCC1 Enters the Nucleus via KPNA2 and Plays an Oncogenic Role in Bladder Cancer

Background: SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin subfamily C member 1 (SMARCC1), a component of the SWI/SNF complex, is thought to be an oncogene in several kinds of cancer.

Materials and methods: The potential interaction between SMARCC1 and KPNA2 was inquired by Spearman’s correlation analysis, immunofluorescence staining and co-immunoprecipitation (Co-IP) assays. The immunohistochemistry staining, RT-PCR and western blot assay were taken for determining the expression levels of SMARCC1. And CCK-8, transwell assay, cell apoptosis assay, cell cycle analysis and subcutaneous tumor model were conducted to explore the role of SMARCC1 in carcinogenesis of bladder cancer.

Results: In our experiments, Spearman’s correlation analysis, immunofluorescence staining and co-immunoprecipitation (Co-IP) assays showed that SMARCC1 interacted with KPNA2, and after knockdown of KPNA2, Nup50 and Nup153, the nuclear content of SMARCC1 decreased while the amount of SMARCC1 protein remaining in the cytoplasm increased, indicating that SMARCC1 could be transported into the nucleus via KPNA2 and thus acted as an oncogene. We found that both the mRNA and protein expression levels of SMARCC1 were increased in bladder cancer, and increased SMARCC1 expression was significantly associated with a higher T stage and poorer prognosis in bladder cancer patients. Knockdown of SMARCC1 slowed the growth of the two tested cell lines and clearly arrested the cell cycle at the G0/G1 phase checkpoint. Moreover, the migratory ability was significantly decreased and the number of apoptotic cells was increased.

Conclusion: On the whole, our results demonstrate KPNA2, Nup50 and Nup153 regulate the process of SMARCC1 nuclear translocation in BC. SMARCC1 may be a competent candidate as a diagnostic and therapeutic target for BC. Further studies are required to research the mechanism and assess the role of SMARCC1 in vivo.

MicroRNA-517c Functions as a Tumor Suppressor in Hepatocellular Carcinoma via Downregulation of KPNA2 and Inhibition of PI3K/AKT Pathway

OBJECTIVE

Hepatocellular carcinoma (HCC) is a kind of solid and highly aggressive malignant tumor with poor prognosis. MicroRNA (miRNA/miR) has been confirmed to be involved in HCC development. The current study focused on the functions and mechanisms of miR-517c in HCC.

METHODS

Expressions of miR-517c and Karyopherin α2 (KPNA2) mRNA in HCC cell lines and tissue samples were examined using quantitative real-time polymerase chain reaction (qRT-PCR). Western blot was conducted for detections of epithelial-to-mesenchymal transition (EMT) and PI3K/AKT markers. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and Transwell assays were utilized to investigate the influence of miR-517c on HCC cell proliferation, invasion, and migration. TargetScan and luciferase reporter assay were performed to search for the potential target gene of miR-517c.

RESULTS

We demonstrated that miR-517c expressions were decreased in HCC tissues and cells. Moreover, the clinical analysis showed that decreased miR-517c expressions in HCC tissues correlated with shorter overall survival and malignant clinicopathologic features of HCC patients. MTT assay showed that miR-517c upregulation prominently repressed HCC cell proliferation. In addition, miR-517c restoration could significantly suppress HCC cell invasion and migration as demonstrated by Transwell assays. We also found that miR-517c directly targeted KPNA2 and regulated the PI3K/AKT pathway and EMT, exerting prohibitory functions in HCC.

CONCLUSION

Taken together, this study stated that miR-517c inhibited HCC progression via regulating the PI3K/AKT pathway and EMT and targeting KPNA2 in HCC, providing a novel insight into HCC treatment.

Integrative bioinformatics analysis of KPNA2 in six major human cancers

Background

Malignant tumors were considered as the leading causes of cancer-related mortality globally. More and more studies found that dysregulated genes played an important role in carcinogenesis. The aim of this study was to explore the significance of KPNA2 in human six major cancers including non-small cell lung cancer (NSCLC), gastric cancer, colorectal cancer, breast cancer, hepatocellular carcinoma, and bladder cancer based on bioinformatics analysis.

Methods

The data were collected and comprehensively analyzed based on multiple databases. KPNA2 mRNA expression in six major cancers was investigated in Oncomine, the human protein atlas, and GEPIA databases. The mutation status of KPNA2 in the six major cancers was evaluated by online data analysis tool Catalog of Somatic Mutations in Cancer (COSMIC) and cBioPortal. Co-expressed genes with KPNA2 were identified by using LinkedOmics and made pairwise correlation by Cancer Regulome tools. Protein-protein interaction (PPI) network relevant to KPNA2 was constructed by STRING database and KEGG pathway of the included proteins of the PPI network was explored and demonstrated by circus plot. Survival analysis-relevant KPNA2 of the six cancers was performed by GEPIA online data analysis tool based on TCGA database.

Results

Compared with paired normal tissue, KPNA2 mRNA was upregulated in all of the six types of cancers. KPNA2 mutations, especially missense substitution, were widely identified in six cancers and interact with different genes in different cancer types. Genes involved in PPI network were mainly enriched in p53 signaling pathway, cell cycle, viral carcinogenesis, and Foxo signaling pathway. KPNA2 protein was mainly expressed in nucleoplasm and cytosol in cancer cells. Immunohistochemistry assay indicated that KPNA2 protein was also positively expressed in nucleoplasm with brownish yellow staining. Overall survival (OS) and progression free survival (PFS) were different between KPNA2 high and low expression groups.

Conclusions

KPNA2 was widely dysregulated and mutated in carcinomas and correlated with the patients prognosis which may be potential target for cancer treatment and biomarker for prognosis.

KPNA2 interaction with CBX8 contributes to the development and progression of bladder cancer by mediating the PRDM1/c-FOS pathway

BACKGROUND

Bladder cancer (BCa) is a common malignancy characterized by high heterogeneity, yet the current treatment modalities are limited. The aim of the present investigation was to unravel the functional role of Karyopherin alpha 2 (KPNA2), a tumor facilitator identified in multiple malignancies, in the progression of BCa.

METHODS

BCa tissues and adjacent normal tissues were surgically resected and analyzed from patients with BCa to determine the expression profile of KPNA2 and Chromobox 8 (CBX8) by RT-qPCR, Western blot analysis and immunohistochemistry. The relationship among KPNA2, CBX8 and PR domain zinc finger protein 1 (PRDM1) was explored by co-immunoprecipitation and chromatin-immunoprecipitation. The functions of KPNA2, CBX8 and PRDM1 on BCa cell proliferation, migration and invasion were evaluated. Next, a nude mouse model of BCa was established for validating the roles of KPNA2, CBX8 and PRDM1 in vivo.

RESULTS

KPNA2 and CBX8 were highly expressed in BCa and are in association with dismal oncologic outcomes of patients with BCa. KPNA2 promoted nuclear import of CBX8. CBX8 downregulated PRDM1 by recruiting BCOR in the promoter region of PRDM1. Overexpression of KPNA2 promoted the malignant behaviors of BCa cells, which was counteracted by silencing of CBX8. Overexpressing PRDM1 attenuated the progression of BCa by inhibiting c-FOS expression. The tumor-promoting effects of KPNA2 via the PRDM1/c-FOS pathway were also validated in vivo.

CONCLUSION

Collectively, our findings attached great importance to the interplay between KPNA2 and CBX8 in BCa in mediating the development and progression of BCa, thus offering a promising candidate target for better BCa patient management.

Increased Nuclear Transporter KPNA2 Contributes to Tumor Immune Evasion by Enhancing PD-L1 Expression in PDAC

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest malignancies and is known for its high resistance and low response to treatment. Tumor immune evasion is a major stumbling block in designing effective anticancer therapeutic strategies. Karyopherin alpha 2 (KPNA2), a member of the nuclear transporter family, is elevated in multiple human cancers and accelerates carcinogenesis. However, the specific role of KPNA2 in PDAC remains unclear. In this study, we found that expression of KPNA2 was significantly upregulated in PDAC compared to adjacent nontumor tissue and its high expression was correlated with poor survival outcome by analyzing the GEO datasets. Similar KPNA2 expression pattern was also found in both human patient samples and KPC mouse models through IHC staining. Although KPNA2 knockdown failed to impair the vitality and migration ability of PDAC cells in vitro, the in vivo tumor growth was significantly impeded and the expression of immune checkpoint ligand PD-L1 was reduced by silencing KPNA2. Furthermore, we uncovered that KPNA2 modulated the expression of PD-L1 by mediating nuclear translocation of STAT3. Collectively, our data suggested that KPNA2 has the potential to serve as a promising biomarker for diagnosis in PDAC.

Zika virus NS2A protein induces the degradation of KPNA2 (karyopherin subunit alpha 2) via chaperone-mediated autophagy

KPNA2/importin-alpha1 (karyopherin subunit alpha 2) is the primary nucleocytoplasmic transporter for some transcription factors to activate cellular proliferation and differentiation. Aberrant increase of KPNA2 level is identified as a prognostic marker in a variety of cancers. Yet, the turnover mechanism of KPNA2 remains unknown. Here, we demonstrate that KPNA2 is degraded via the chaperone-mediated autophagy (CMA) and that Zika virus (ZIKV) enhances the KPNA2 degradation. KPNA2 contains a CMA motif, which possesses an indispensable residue Gln109 for the CMA-mediated degradation. RNAi-mediated knockdown of LAMP2A, a vital component of the CMA pathway, led to a higher level of KPNA2. Moreover, ZIKV reduced KPNA2 via the viral NS2A protein, which contains an essential residue Thr100 for inducing the CMA-mediated KPNA2 degradation. Notably, mutant ZIKV with T100A alteration in NS2A replicates much weaker than the wild-type virus. Also, knockdown of KPNA2 led to a higher ZIKV viral yield, which indicates that KPNA2 mediates certain antiviral effects. These data provide insights into the KPNA2 turnover and the ZIKV-cell interactions.

Diagnostic significance and carcinogenic mechanism of pan-cancer gene POU5F1 in liver hepatocellular carcinoma

BACKGROUND

The prognostic and clinicopathological significance of POU Class 5 Homeobox 1 (POU5F1) among various cancers are disputable heretofore. The diagnostic value and functional mechanism of POU5F1 in liver hepatocellular carcinoma (LIHC) have not been studied thoroughly.

METHODS

An integrative strategy of meta-analysis, bioinformatics, and wet-lab approach was used to explore the diagnostic and prognostic significance of POU5F1 in various types of tumors, especially in LIHC. Meta-analysis was utilized to investigate the impact of POU5F1 on prognosis and clinicopathological parameters in various cancers. The expression level and diagnostic value of POU5F1 were assessed by qPCR in plasma collected from LIHC patients and controls. The correlation between POU5F1 and tumor infiltrating immune cells (TIICs) in LIHC was evaluated by CIBERSORT. Gene set enrichment analysis (GSEA) was performed based on TCGA. Hub genes and related pathways were identified on the basis of co-expression genes of POU5F1.

RESULTS

Elevated POU5F1 was associated with poor OS, DFS, RFS, and DSS in various cancers. POU5F1 was confirmed as an independent risk factor for LIHC and correlated with tumor occurrence, stage, and invasion depth. The combination of POU5F1 and AFP in plasma was with high diagnostic validity (AUC = 0.902, p < .001). Specifically, the level of POU5F1 was correlated with infiltrating levels of B cells, T cells, dendritic cells, and monocytes in LIHC. GSEA indicated that POU5F1 participated in multiple cancer-related pathways and cell proliferation pathways. Moreover, CBX3, CCHCR1, and NFYC were filtered as the central hub genes of POU5F1.

CONCLUSION

Our study identified POU5F1 as a pan-cancer gene that could not only be a prognostic and diagnostic biomarker in various cancers, especially in LIHC, but functionally carcinogenic in LIHC.

Prognostic value of octamer binding transcription factor 4 for patients with solid tumors: A meta-analysis

BACKGROUND

Octamer binding transcription factor 4 (Oct4) is critically important in the development and progression of cancer, and is considered a potential biomarker for tumor prognosis. However, the prognostic value of Oct4 in patients with solid tumors remains elusive. Herein, we conducted a meta-analysis to assess the prognostic value of Oct4 in patients with solid tumors.

METHODS

We conducted a literature search on PubMed, Embase, and Web of Science databases to retrieve comprehensive and eligible studies published until December 2019. The study was conducted per the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The pooled hazard ratios (HRs) with 95% confidence intervals (CIs) of overall survival (OS) and disease-free survival (DFS)/recurrence-free survival (RFS)/progress-free survival (PFS) were used to evaluate the prognostic value of Oct4 in patients with solid tumors via either random or fixed-effects models.

RESULTS

In total, 36 studies with 5198 patients were included in the meta-analysis. Notably, elevated Oct4 expression was associated with worse OS (pooled HR: 2.02, 95% CI: 1.55-2.62, P < .001) and DFS/RFS/PFS (pooled HR: 2.34, 95% CI: 1.88-2.92, P < .001).

CONCLUSION

This work demonstrated that patients with solid tumors show high expression of Oct4 which is linked to worse prognosis in patients with solid tumors including hepatocellular carcinoma (OS, DFS/RFS/PFS), esophageal squamous cell carcinoma (OS), gastric cancer (OS), cervical cancer (OS, DFS/RFS/PFS), and colorectal cancer (OS, DFS/RFS/PFS), this implicated Oct4 as a potential biomarker to predict the prognosis of tumors.

Overexpression of Karyopherin Subunit alpha 2 (KPNA2) Predicts Unfavorable Prognosis and Promotes Bladder Cancer Tumorigenicity via the P53 Pathway

Background

We sought to investigate the expression of KPNA2 in bladder cancer (BC) and its relationship with prognosis, and to analyze the potential mechanism of KPNA2 in promoting BC progression.

Material/Methods

The RNA-seq data on BC from The Cancer Genome Atlas (TCGA) database were imported into R statistical software for differential analysis. The clinical data for patients with BC were screened and analyzed with R software. The survival curve was drawn with the Kaplan-Meier Plotter. The expression of KPNA2 in 4 human BC cell lines and a human bladder epithelial cell line was detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting (WB). The proliferation of BC cells was detected with Cell Counting Kit-8 (CCK8), detection of apoptosis, and flow cytometry, and the migration and invasion of BC cells were detected through Transwell assays. WB was used to detect proteins involved in the P53 pathway.

Results

The expression of KPNA2 was higher in BC. The difference in KPNA2 expression was associated with many clinicopathological factors, and high expression of KPNA2 was associated with shorter survival time. After KPNA2 knockout, the proliferation, migration, and invasion ability decreased significantly, the cell cycle was clearly arrested in the G0/G1 phase, and the number of apoptotic cells increased. Moreover, CyclinD1, BCL2, and pro-caspase3 decreased significantly, whereas P53, P21, BAX, and cleaved-caspase3 increased significantly. The results in the overexpression group were the opposite of results in the knockdown group.

Conclusions

KPNA2 is an oncogenic factor that facilitates BC tumorigenicity through the P53 pathway.

Identification of Key Biomarkers in Bladder Cancer: Evidence from a Bioinformatics Analysis

Bladder cancer (BCa) is one of the most common malignancies and has a relatively poor outcome worldwide. However, the molecular mechanisms and processes of BCa development and progression remain poorly understood. Therefore, the present study aimed to identify candidate genes in the carcinogenesis and progression of BCa. Five GEO datasets and TCGA-BLCA datasets were analyzed by statistical software R, FUNRICH, Cytoscape, and online instruments to identify differentially expressed genes (DEGs), to construct protein‒protein interaction networks (PPIs) and perform functional enrichment analysis and survival analyses. In total, we found 418 DEGs. We found 14 hub genes, and gene ontology (GO) analysis revealed DEG enrichment in networks and pathways related to cell cycle and proliferation, but also in cell movement, receptor signaling, and viral carcinogenesis. Compared with noncancerous tissues, TPM1, CRYAB, and CASQ2 were significantly downregulated in BCa, and the other hub genes were significant upregulated. Furthermore, MAD2L1 and CASQ2 potentially play a pivotal role in lymph nodal metastasis. CRYAB and CASQ2 were both significantly correlated with overall survival (OS) and disease-free survival (DFS). The present study highlights an up to now unrecognized possible role of CASQ2 in cancer (BCa). Furthermore, CRYAB has never been described in BCa, but our study suggests that it may also be a candidate biomarker in BCa.

The emerging roles of KPNA2 in cancer

Karyopherin α2 (KPNA2, also known as importinα-1), a member of the nuclear transporter family, is involved in the nucleocytoplasmic transport pathway of a variety of tumor-associated proteins. Recent studies have found that KPNA2 is overexpressed in various cancers, which is associated with poor prognosis. In addition, it has been shown to promote tumor formation and progression by participating in cell differentiation, proliferation, apoptosis, immune response, and viral infection. It is indicated that KPNA2 also plays an important role in the diagnosis, treatment and prognosis of tumors. Herein, we provide an overview of the function and mechanism of KPNA2 in cancer and the prospects in the diagnosis and treatment of cancer. In the future, KPNA2 provides new ideas for the early diagnosis of malignant tumors, the development of molecularly targeted drugs, and prognosis evaluation.

Silencing of KPNA2 inhibits high glucose-induced podocyte injury via inactivation of mTORC1/p70S6K signaling pathway

Dysregulation of apoptotic and autophagic function are characterized as the main pathogeneses of diabetic nephropathy (DN). It has been reported that Karyopherin Alpha 2 (KPNA2) contributes to apoptosis and autophagy in various cells, but its role in DN development remains unknown. The purpose of present study was to explore the function and underling mechanisms of KPNA2 in development of DN. In this study, 30 mM high glucose (HG)-evoked podocytes were used as DN model. The expression of KPNA2 was detected by qRT-PCR and Western blot assays. The cell viability was tested by CCK-8 kit, the apoptosis was measured using flow cytometry assay, the apoptotic and the autophagy related genes was detected by Western blot. Our results indicated that KPNA2 was significantly increased after HG stimulation. Knockdown of KPNA2 inhibited apoptosis, and promoted cell viability and autophagy in HG-treated podocytes. In addition, silencing of KPNA2 deactivated mTORC1/p70S6K pathway activation via regulating SLC1A5. Further results demonstrated that activating mTORC1/p70S6K pathway strongly ameliorated the effect of KPNA2 on cell viability, apoptosis and autophagy. Therefore, our study suggested that knockdown of KPNA2 rescued HG-induced injury via blocking activation of mTORC1/p70S6K pathway by mediating SLC1A5.

Integrated analysis of quantitative proteome and transcriptional profiles reveals abnormal gene expression and signal pathway in bladder cancer

BACKGROUND

Bladder cancer (BCa) is a tumor associated with high morbidity and mortality and its incidence is increasing worldwide. However, the pathogenesis of bladder cancer is not well understood.

OBJECTIVE

To further illustrate the molecular mechanisms involved in the pathogenesis of BCa and identify potential therapeutic targets, we combined the transcriptomic analysis with RNA sequencing and tandem mass tags (TMT)-based proteomic methods to quantitatively screen the differentially expressed genes and proteins between bladder cancer tissues (BC) and adjacent normal tissues (AN).

RESULTS

Transcriptome and proteome studies indicated 7094 differentially expressed genes (DEGs) and 596 differentially expressed proteins (DEPs) between BC and AN, respectively. GO enrichment analyses revealed that cell adhesion, calcium ion transport, and regulation of ATPase activity were highly enriched in BCa. Moreover, several key signaling pathway were identified as of relevance to BCa, in particular the ECM-receptor interaction, cell adhesion molecules (CAMs), and PPAR signaling pathway. Interestingly, 367 genes were shared by DEGs and DEPs, and a significant positive correlation between mRNA and translation profiles was found.

CONCLUSION

In summary, this joint analysis of transcript and protein profiles provides a comprehensive reference map of gene activity regarding the disease status of BCa.

Low Expression of Pseudogene POU5F1B Affects Diagnosis and Prognosis in Acute Myeloid Leukemia (AML)

Background

The transcription factor Oct-4 is necessary for maintaining pluripotency and self-renewal of embryonic stem cells, and POU5F1B is a processed pseudogene of Oct-4 with coding capacity. The purpose of this study is to evaluate the expression and clinical implication of POU5F1B in AML.

Material/Methods

The expression of the POU5F1B transcript was evaluated in 175 newly diagnosed AML patients and 39 healthy controls by use of real-time quantitative PCR (RQ-PCR).

Results

POU5F1B was underexpressed in AML compared with controls (P<0.001). The receiver operating characteristic (ROC) curve revealed that the POU5F1B transcript level was able to differentiate AML patients from healthy individuals (AUC=0.682). In non-APL AML patients, the POU5F1B^low group had significantly higher WBC than the POU5F1B^high group (20.2×10⁹vs. 4.6×10⁹ L⁻¹, P=0.021). Among whole-cohort AML, non-APL AML, and intermediate-risk AML, POU5F1B^high patients had obviously higher complete remission (CR) rates than POU5F1B^low patients (P=0.012, P=0.012 and P=0.027). In addition, Kaplan-Meier analysis demonstrated better overall survival (OS, P=0.019, P=0.007 and P=0.046, respectively) in POU5F1B^high patients compared with POU5F1B^low patients. Furthermore, in multivariate survival analysis, POU5F1B was independently associated with OS in non-APL AML patients and intermediate-risk AML as a favorable prognostic factor.

Conclusions

POU5F1B was frequently underexpressed in AML, and might contribute to the diagnosis and prognosis of AML.

Upregulated KPNA2 promotes hepatocellular carcinoma progression and indicates prognostic significance across human cancer types

Hepatocellular carcinoma (HCC) is one of the most aggressive cancers worldwide. Identification of the molecular mechanisms underlying the development and progression of HCC is particularly important. Here, we demonstrated the expression pattern, clinical significance, and function of Karyopherin α2 (KPNA2) in HCC. The expression of KPNA2 was upregulated in tumor tissue and negatively associated with the survival time, and a significant correlation between KPNA2 expression and aggressive clinical characteristics was established. Both in vitro and in vivo experiments demonstrated that knockdown of KPNA2 reduced migration and proliferation capacities of HCC cells, while over-expression of KPNA2 increased these malignant characteristics. The analysis of the Cancer Genome Atlas cohorts also reveals that high-KPNA2 expression is associated with poor outcome in multiple cancer types. In addition, gene sets enrichment analysis exhibited cell cycle and DNA replication as the top altered pathways in the high-KPNA2 expression group in HCC and other two cancer types. Overall, this study identified KPNA2 as a potential diagnostic and prognostic biomarker in HCC and other neoplasms, probably by regulating cell cycle and DNA replication.

lncRNA SLCO4A1-AS1 promotes growth and invasion of bladder cancer through sponging miR-335-5p to upregulate OCT4

Background

Bladder cancer (BC) is among the most frequently occurring cancer types in the urinary system. In recent years, the importance of lncRNAs in BC has been acknowledged. SLCO4A1-AS1 is an oncogene in colorectal cancer. However, the role of SLCO4A1-AS1 in BC remains unknown.

Materials and methods

The expression levels of SLCO4A1-AS1 in BC tissues were analyzed by qRT-PCR. The effects of SLCO4A1-AS1 knockdown on proliferation were determined by CCK8 assay. Transwell assay was used to evaluate the role of SLCO4A1-AS1 on migration and invasion. Furthermore, xenograft assay was utilized to test the effect of SLCO4A1-AS1 on BC growth in vivo.

Results

SLCO4A1-AS1 expression was more upregulated in BC tissues than in adjacent normal tissues. Moreover, SLCO4A1-AS1 level was positively correlated with the advanced stage and metastasis in BC. The upregulation of SLCO4A1-AS1 indicates poor prognosis in BC patients. The knockdown of SLCO4A1-AS1 downregulated the proliferation, migration, and invasion of EJ and T24 cells in vitro. In addition, the loss of SLCO4A1-AS1 prevented BC growth in vivo. Mechanistic investigation showed that SLCO4A1-AS1 was the sponge for miR-335-5p, and miR-335-5p modulated OCT4 expression.

Conclusion

High SLCO4A1-AS1 expression level was associated with the progression of BC, and SLCO4A1-AS1 promoted the malignant phenotypes of BC cells through the miR-335-5p/OCT4 axis.

Karyopherin Alpha 2 Is an Adverse Prognostic Factor in Clear-Cell and Papillary Renal-Cell Carcinoma

BACKGROUND

Karyopherin α2 (KPNA2) is involved in the nucleocytoplasmic transport system and is functionally involved in the pathogenesis of various solid tumors by the translocation of cancer associated cargo proteins. However, the role of KPNA2 in renal-cell carcinoma (RCC) is still unknown. The aim of the present study was to investigate the protein expression of KPNA2 in cancerous and healthy renal tissues to evaluate its prognostic value in RCC.

PATIENTS AND METHODS

We assessed KPNA2 protein expression via immunohistochemistry in a well-characterized cohort of 240 RCC patients by using a quantitative image analysis software. In addition, we analyzed publicly available gene expression data from The Cancer Genome Atlas (TCGA).

RESULTS

A subgroup of clear-cell RCC (ccRCC) showed elevated protein expression levels of KPNA2. Most remarkably, we detected a correlation between high KPNA2 protein expression and shorter overall survival times as well as higher tumor stage and International Society of Urologic Pathology grade in ccRCC. However, the prognostic value of KPNA2 was not confirmed by multivariate Cox regression analysis when tested together with strong prognostic factors like tumor stage, lymph node metastasis, International Society of Urologic Pathology grade, and resection status. The results of the TCGA gene expression data analysis confirmed the prognostic value of KPNA2 in ccRCC. Additionally, KPNA2 expression was identified as an adverse factor in papillary RCC at the transcript level.

CONCLUSION

KPNA2 appears to be involved in the carcinogenesis of RCC and functions as a novel prognostic indicator.

Knockdown of KPNA2 inhibits autophagy in oral squamous cell carcinoma cell lines by blocking p53 nuclear translocation

Oral squamous cell carcinoma (OSCC), one of the 10 most common types of neoplasms in the US, constitutes ~90% of all cases of oral malignancies. Chemoresistance and metastasis are difficult to avoid during the course of treatment, leading to a poor prognosis and a high mortality rate for patients with OSCC. Autophagy, a critical conserved cellular process, has been reported to be highly associated with the regulation of chemoresistance and metastasis of cancer cells. The present study investigated the role of karyopherin α2 (KPNA2), a member of the importin α family, which may serve an important role in p53 nucleocytoplasmic transport in the process of OSCC autophagy. In the CAL-27, SCC-15 and Tca8113 OSCC cell lines, we observed that the downregulation of KPNA2 suppressed cell migration and cisplatin resistance, using wound-healing, Transwell and CCK-8 assays. Additionally, the results of western blot analysis and transmission electron microscopy (TEM) analysis indicated that the knockdown of KPNA2 inhibited autophagy. We confirmed that the inhibition of autophagy with anti-autophagy agents decreased the migration and cisplatin resistance of OSCC cells. We hypothesized that the suppression of cell migration and cisplatin resistance induced by KPNA2 knockdown may be associated with the inhibition of autophagy. To identify the underlying mechanism, further experiments determined that KPNA2 affects the level of autophagy via regulating the p53 nuclear import. Thus, the present study demonstrated that the function of KPNA2 in the process of autophagy may be p53-dependent, and by regulating the translocation of p53, KPNA2 can support autophagy to promote the chemoresistance and metastasis of OSCC cells.

Differential expression of Oct3/4 in human breast cancer and normal tissues

Oct3/4, a transcription factor specifically expressed in mammalian totipotent embryonic stem and germ cells, has a critical role in the regulation and maintenance of pluripotency and self-renewal. However, reactivation of Oct3/4 expression is observed in several human breast cancer cell lines, but not in non‑malignant cells. To examine Oct3/4 expression in human primary breast carcinomas and normal breast tissues, we obtained breast tumor tissues from 28 patients and normal breast tissues from 9 women. According to quantitative polymerase chain reaction, all of the tumor tissues, irrespective of tumor type or clinicopathological status, expressed Oct3/4 mRNA at 10- to 100- fold higher levels than that in the normal breast tissues. Expression of the Oct3/4 protein in tumors was confirmed by western blot analysis and immunofluorescent staining. Additionally, rapid amplification of cDNA ends and DNA sequencing revealed expression of multiple Oct4 gene transcripts from chromosome 6 (POU5F1) in normal breast tissues and the non‑malignant breast epithelial cell line MCF‑10A; by contrast, the breast tumors and malignant breast cancer cell line MCF‑7 predominantly expressed transcripts of an Oct4-like gene (POU5F1B) from chromosome 8, which was termed Oct3 in the current study. The deduced amino acid sequences of full-length Oct3 and Oct4 are 96% identical. The findings of the current study indicated that Oct3, rather than Oct4, may serve as a novel clinical marker and a potential target for gene-specific therapy of breast cancer.

Karyopherins in cancer

Malfunction of nuclear-cytoplasmic transport contributes to many diseases including cancer. Defective nuclear transport leads to changes in both the physiological levels and temporal-spatial location of tumor suppressors, proto-oncogenes and other macromolecules that in turn affect the tumorigenesis process and drug sensitivity of cancer cells. In addition to their nuclear transport functions in interphase, Karyopherin nuclear transport receptors also have important roles in mitosis and chromosomal integrity. Therefore, alterations in the expressions or regular functions of Karyopherins may have substantial effects on the course and outcome of diseases.

Significant expression of CHK1 and p53 in bladder urothelial carcinoma as potential therapeutic targets and prognosis

Checkpoint kinase 1 (CHK1) and p53 are involved in cell-cycle checkpoint, and cellular response to DNA damage. CHK1 and p53 are overexpressed in bladder urothelial carcinoma (BUC); however, a clear elucidation on their interaction and influence in the progress of BUC is absent. The aim of the present study was to examine the correlation between CHK1 and p53 in BUC, and analyze their value as therapeutic targets and prognostic indicators in BUC. A clinically annotated cohort of 110 patients with BUC was identified retrospectively. EnVision-based immunohistochemistry and western blot analysis of the aforementioned DNA repair proteins were conducted on formalin-fixed-paraffin-embedded or frozen tissues from the primary tumor. A total of 45 peritumoral tissue cases were assessed similarly as the control group. In the cohort of 110 patients with BUC, a significant overexpression of CHK1 and p53 was observed in primary compared with the peritumoral tissues (P<0.05). CHK1 and p53 demonstrated a positive correlation in BUC, and both were positively associated with the histological grade, clinical pathological staging, lymphatic metastasis and the 5-year survival rate (P<0.05). However, CHK1 and p53 were not associated with sex, age, tumor diameter, single/multiple sites or incipient/recurrence. The overexpression of CHK1 and p53, and their synergistic interaction were putatively correlated with the physiology of BUC that may be deemed as potential therapeutic targets and prognostic indicators.