ARK5 is associated with the invasive and metastatic potential of human breast cancer cells

NUAKs promote mTOR/c-Myc-induced glucose and glutamine reprogramming for cell growth and metastasis in breast cancer cells

Breast cancer progression and metastasis are closely connected to changes in glucose and glutamine metabolism. While Novel (nua) kinase family 1 (NUAK1) and Novel (nua) kinase family 2 (NUAK2), which are two members of the AMPK-related kinases, have been associated with breast tumorigenesis, their role in the metabolic reprogramming that occurs during breast cancer progression remains unclear. Our research uncovers that NUAKs expression is significantly higher in breast cancer tissues and cell lines, and it is positively related to glycolysis, the pentose phosphate pathway (PPP), glutamine metabolism, and a poor prognosis for breast cancer patients. We show that NUAKs significantly increase metabolic reprogramming, including aerobic glycolysis, PPP, and glutamine metabolism in triple negative breast cancer subtypes but only induce aerobic glycolysis and PPP in luminal breast cancer subtypes to meet the anabolic demands of rapidly dividing breast cancer cells. In contrast, the depletion of NUAKs has the opposite effect. Mechanistic insights reveal that NUAKs activate mammalian target of rapamycin (mTOR) signaling, which in turn upregulates the c-Myc transcription factor, a crucial regulator of glucose and glutamine metabolic gene expression. Moreover, we demonstrate that NUAKs enhance mTOR/c-Myc signaling pathways, leading to increased glucose and glutamine reprogramming, which supports rapid cell proliferation and metastatic potential in breast cancer cells. Importantly, pretreating breast cancer cells with mTOR inhibitors blocked the metabolic reprogramming and tumor-promoting effect of NUAK1/2. Therefore, targeting NUAKs may represent a novel therapeutic strategy for the treatment of breast cancer.

Prognostic significance of NUAK1 and its association with immune infiltration in stomach adenocarcinoma

BACKGROUND

Stomach adenocarcinoma (STAD) represents a significant global health burden, accounting for a considerable proportion of cancer-related mortalities, and NUAK1, a protein kinase, plays a crucial role in cellular metabolism, cell cycle regulation, migration, and tumor progression. However, its relationship with prognosis and immune infiltration in STAD has not been thoroughly investigated.

METHODS

RNA sequencing data from the Cancer Genome Atlas (TCGA) and Genotypic Tissue Expression Project (GTEx) databases were employed to assess disparities in NUAK1 expression between STAD tumour and normal tissues. Additionally, we investigated the correlation between NUAK1 expression and patient prognosis, in addition to the level of immune cell infiltration. The potential functions were elucidated through an examination of the Gene Ontology (GO) Encyclopedia, the Kyoto Encyclopedia of Genes and Genomes (KEGG), and an enrichment analysis (GSEA). The GeneMANIA was used to validate the functions of nuak1-related genes.

RESULTS

Our analysis demonstrated that NUAK1 expression in tumour tissues exhibited a notable disparity from that observed in normal tissues, with elevated levels detected in STAD tissues. We used the GeneMANIA database to identify functionally similar genes with significantly higher expression for some genes in the unpaired group samples. An elevated NUAK1 expression level was found to correlate with a poorer overall survival (OS), disease-specific survival (DSS), and progression-free intervals (PFI). Additionally, immune infiltration analysis indicated a significant positive correlation between NUAK1 expression and various tumor-infiltrating immune cells, while a negative correlation was observed with T helper cell 17(Th17) cells. Furthermore, enrichment analysis was conducted to identify relevant biological features and pathways.

CONCLUSION

The expression levels of NUAK1 are significantly increased in STAD, and this heightened expression correlates with diminished OS, DSS, and PFI among affected patients. These observations indicate that NUAK1 has the potential to function as a prognostic biomarker for STAD and may represent a viable therapeutic target for intervention in its management.

Discovery of UCB9386: A Potent, Selective, and Brain-Penetrant Nuak1 Inhibitor Suitable for In Vivo Pharmacological Studies

Nuak1 (NUAK family SnF1-like kinase-1) is a serine-threonine kinase and a member of the AMPK family. Interest in Nuak1 has increased over the years due to the role it plays in several biological processes, from tumor cell invasion and proliferation to Tau stabilization. Nuak1 is expressed in many cancer cell lines and many reports describe this target as an oncogene, the inhibition of which is hypothesized to be valuable for treating various cancer types including glioma. We report here the discovery of Nuak1 inhibitors originating from HTS hit 9 with excellent selectivity and the subsequent medicinal chemistry optimization program, supported by structural information from the first crystal structures of a Nuak1 chimeric protein which provided insights into the binding modes of our compounds. These efforts yielded a nanomolar cell potent, highly selective and brain penetrant Nuak1 inhibitor UCB9386 (56) suitable for in vivo pharmacological studies for central nervous system (CNS) disorders.

NUAK1 promotes tumor metastasis through upregulating slug transcription in esophageal squamous cell carcinoma

BACKGROUND

Metastasis is still a major cause of poor pathological outcome and prognosis in esophageal squamous cell carcinoma (ESCC) patients. NUAK1 has been reported highly expressed in many human cancers and is associated with the poor prognosis of cancer patients. However, the role of NUAK1 and its underlying signaling mechanism in ESCC metastasis remain unclear.

METHODS

Expression of NUAK1 in ESCC was detected by real-time quantitative RT-PCR (qRT-PCR), Western blotting and immunohistochemical staining. MTT, colony formation, wound-healing and transwell assays were used to determine the role NUAK1 in vitro. Metastasis was evaluated by use of an experimental pulmonary metastasis model in BALB/c-nu/nu mice. The mechanisms were assessed by using coimmunoprecipitation, immunofluorescence and dual-luciferase reporter gene experiments.

RESULTS

NUAK1 was highly expressed in ESCC tissues compared with the adjacent normal esophageal epithelial tissues. Moreover, the elevated expression of NUAK1 positively correlated with tumor invasion depth, lymph node metastasis, pathological TNM stage, and poor survival in ESCC patients. Further experiments showed that NUAK1 overexpression did not change the cell viability and colony formation of ESCC cells, while remarkably promoted the migration and invasion in vitro and experimental pulmonary metastasis in vivo. Mechanistically, NUAK1 enhanced the transcription level of Slug, which enhanced the migratory and invasive capability of ESCC cells. Consistently, silencing Slug almost completely diminished the migration and invasion of NUAK1-overexpressing ESCC cells. Further studies demonstrated that NUAK1 upregulated the transcription activity of Slug through activating the JNK/c-Jun pathway.

CONCLUSION

These results demonstrated that NUAK1 promoted the metastasis of ESCC cells through activating JNK/c-Jun/Slug signaling, indicating NUAK1 is a promising therapeutic target for metastatic ESCC.

DKK1 promotes NUAK1 transcriptional expression through the activation Akt in hepatocellular carcinoma

NUAK1 is a serine/threonine kinase that has been shown to be associated with poor prognosis in several cancers. Although NUAK1 is frequently overexpressed at the transcript level in hepatocellular carcinoma (HCC), the actual role of NUAK1 and the mechanism of its overexpression in HCC has yet to be reported. In the present study, we found that NUAK1 expression was significantly increased in human HCC tumor tissues. Overexpression of NUAK1 dramatically enhanced HCC cells proliferation and migration in vitro. Stable induction of NUAK1 expression promoted tumor growth and tumor metastases to the lungs in the subcutaneous xenograft models and intravenous metastasis models. At the cellular level, enforced expression of Dickkopf-1 (DKK1) activated the Akt signaling pathway, thereby promoting the mRNA and protein expression of NUAK1 in HCC cells. By contrast, depletion of DKK1 was found to attenuate the mRNA and protein expression of NUAK1. In the subcutaneous xenograft models, stable induction of DKK1 expression not only accelerated tumor growth but also increased p-Akt and NUAK1 expression; whereas knockdown of DKK1 inhibited tumor growth, p-Akt and NUAK1 expression. Furthermore, immunohistochemical analysis of 20 HCC clinical samples showed that the expression level of NUAK1 was positively correlated with DKK1 and p-Akt. Taken together, we provide the first evidence that DKK1 promotes NUAK1 transcriptional expression via the activation Akt in HCC.

AMPK-like proteins and their function in female reproduction and gynecologic cancer

Serine-threonine kinase (STK11), also known as liver kinase B1 (LKB1), is a regulator of cellular homeostasis through regulating the cellular ATP-to-ADP ratio. LKB1 is classified as a tumor suppressor and functions as the key activator of AMP-activated protein kinase (AMPK) and a family of serine-threonine kinases called AMPK-like proteins. These proteins include novel (nua) kinase family 1 (NUAK1 and 2), salt inducible kinase (SIK1), QIK (known as SIK2), QSK (known as SIK3 kinase), and maternal embryonic leuzine zipper kinase (MELK) on tightly controlled and specific residual sites. LKB1 also regulates brain selective kinases 1 and 2 (BRSK1 and 2), additional members of AMPK-like protein family, which functions are probably less studied. AMPK-like proteins play a role in variety of reproductive physiology functions such as follicular maturation, menopause, embryogenesis, oocyte maturation, and preimplantation development. In addition, dysfunctional activity of AMPK-like proteins contributes to apoptosis blockade in cancer cells and induction of the epithelial-mesenchymal transition required for metastasis. Dysregulation of these proteins occurs in ovarian, endometrial, and cervical cancers. AMPK-like proteins are still undergoing further classification and may represent novel targets for targeted gynecologic cancer therapies. In this chapter, we describe the AMPK-like family of proteins and their roles in reproductive physiology and gynecologic cancers.

Elucidating tumor heterogeneity from spatially resolved transcriptomics data by multi-view graph collaborative learning

Spatially resolved transcriptomics (SRT) technology enables us to gain novel insights into tissue architecture and cell development, especially in tumors. However, lacking computational exploitation of biological contexts and multi-view features severely hinders the elucidation of tissue heterogeneity. Here, we propose stMVC, a multi-view graph collaborative-learning model that integrates histology, gene expression, spatial location, and biological contexts in analyzing SRT data by attention. Specifically, stMVC adopting semi-supervised graph attention autoencoder separately learns view-specific representations of histological-similarity-graph or spatial-location-graph, and then simultaneously integrates two-view graphs for robust representations through attention under semi-supervision of biological contexts. stMVC outperforms other tools in detecting tissue structure, inferring trajectory relationships, and denoising on benchmark slices of human cortex. Particularly, stMVC identifies disease-related cell-states and their transition cell-states in breast cancer study, which are further validated by the functional and survival analysis of independent clinical data. Those results demonstrate clinical and prognostic applications from SRT data.

AMPK-related protein kinase ARK5 regulates subcellular localization of RNA-binding protein hnRNP A1 during hypertonic stress

The heterogeneous nuclear ribonucleoprotein hnRNP A1 is a nucleocytoplasmic-shuttling RNA-binding protein that plays an important role in nucleic acid metabolism and gene expression regulation. The function of hnRNP A1 is determined in part by its specific location within the cell. Although some work has been done to elucidate the signaling pathways that regulate the cellular localization of hnRNP A1, the precise mechanism(s), including physiological and pathophysiological conditions that alter hnRNP A1 localization, are not known. We previously conducted an unbiased RNAi-based kinome-wide screen to identify kinases that regulate hnRNP A1 localization during hypertonic stress. One of the hits from this screen is AMPK-related protein kinase 5 (ARK5). Here, we validate ARK5 as the kinase responsible for controlling hnRNP A1 subcellular localization in response to hypertonic stress. We find using immunoprecipitation and in vitro kinase assay methods that ARK5 directly interacts with and phosphorylates hnRNP A1 on serine residues within the F-peptide region. We further show that the M9 motif of hnRNP A1 is essential for the ARK5-hnRNP A1 interaction and subsequent phosphorylation. In addition, the silencing of ARK5 increases the expression of anti-apoptotic protein Bcl-xL and consequently delays caspase activation during hypertonic stress. Our results indicate that ARK5 phosphorylates hnRNP A1 and regulates its subcellular localization during hypertonic stress.

Discovery of a novel NUAK1 inhibitor against pancreatic cancer

The novel (nua) kinase family 1 (NUAK1) is an AMPK-related kinase and its expression is associated with tumor malignancy and poor prognosis in several types of cancer, suggesting its potential as a target for cancer therapy. Therefore, the development of NUAK1-targeting inhibitors could improve therapeutic outcomes in cancer. We synthesized KI-301670, a novel NUAK1 inhibitor, and assessed its anticancer effects and mechanism of action in pancreatic cancer. It effectively inhibited pancreatic cancer growth and proliferation, and induced cell cycle arrest, markedly G0/G1 arrest, by increasing the expression of p27 and decreasing expression of p-Rb and E2F1. Additionally, the apoptotic effect of KI-301670 was observed by an increase in cleaved PARP, TUNEL-positive cells, and annexin V cell population, as well as the release of cytochrome c via the loss of mitochondrial membrane potential. KI-301670 inhibited the migration and invasion of pancreatic cancer cells. Mechanistically, KI-301670 effectively inhibited the PI3K/AKT pathway in pancreatic cancer cells. Furthermore, it significantly attenuated tumor growth in a mouse xenograft tumor model. Our results demonstrate that a novel NUAK1 inhibitor, KI-301670, exerts anti-tumor effects by directly suppressing cancer cell growth by affecting the PI3K/AKT pathway, suggesting that it could be a novel therapeutic candidate for pancreatic cancer treatment.

NUAK Kinases: Brain-Ovary Axis

Liver kinase B (LKB1) and adenosine monophosphate (AMP)-activated protein kinase (AMPK) are two major kinases that regulate cellular metabolism by acting as adenosine triphosphate (ATP) sensors. During starvation conditions, LKB1 and AMPK activate different downstream pathways to increase ATP production, while decreasing ATP consumption, which abrogates cellular proliferation and cell death. Initially, LKB1 was considered to be a tumor suppressor due to its loss of expression in various tumor types. Additional studies revealed amplifications in LKB1 and AMPK kinases in several cancers, suggesting a role in tumor progression. The AMPK-related proteins were described almost 20 years ago as a group of key kinases involved in the regulation of cellular metabolism. As LKB1-downstream targets, AMPK-related proteins were also initially considered to function as tumor suppressors. However, further research demonstrated that AMPK-related kinases play a major role not only in cellular physiology but also in tumor development. Furthermore, aside from their role as regulators of metabolism, additional functions have been described for these proteins, including roles in the cell cycle, cell migration, and cell death. In this review, we aim to highlight the major role of AMPK-related proteins beyond their functions in cellular metabolism, focusing on cancer progression based on their role in cell migration, invasion, and cell survival. Additionally, we describe two main AMPK-related kinases, Novel (nua) kinase family 1 (NUAK1) and 2 (NUAK2), which have been understudied, but play a major role in cellular physiology and tumor development.

LINC00922 promotes the proliferation, migration, invasion and EMT process of liver cancer cells by regulating miR-424-5p/ARK5

AMPK-related protein kinase 5 (ARK5) promotes the deterioration of hepatocellular carcinoma (HCC). From the perspective of lncRNA-miRNA-mRNA, this study explored in-depth the intervention mechanism of ARK5. The binding relationship between miR-424-5p and two genes (LINC00922 and ARK5) were analyzed by Bioinformatics and dual-luciferase experiments. After clinical sample collection, the expressions of miR-424-5p, LINC00922 and ARK5 in HCC tissues were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). The correlation between LINC00922, miR-424-5p, and ARK5 in HCC tissues was analyzed by Pearson correlation. The influences of miR-424-5p, LINC00922 and ARK5 on the basic functions (viability, migration and invasion) of cancer cells were detected by cell counting kit-8, wound healing, and Transwell experiments, and their regulatory effects on related genes, as well as their relationship, were tested by qRT-PCR and Western blot. MiR-424-5p was low expressed, whereas LINC00922 and ARK5 were high expressed in HCC tissues. MiR-424-5p was negatively associated with LINC00922 and ARK5 that was positively associated with LINC00922. Interestingly, LINC00922 partially shared an identical binding site of miR-424-5p with ARK5. LINC00922 its overexpression partially offset the inhibitory effect of miR-424-5p on cancer cell functions. ARK5 silencing repressed the malignant phenotype of cancer cells and inhibited the expressions of epithelial-to-mesenchymal transition (EMT)-related molecules (Vimentin, Snail and N-Cadherin). However, these effects were partially neutralized by miR-424-5p inhibitors. LINC00922 increases the cell viability, migration, invasion and EMT process of HCC cells by regulating the miR-424-5p/ARK5 axis, and thus may serve as a potential target for targeted therapy.

Role of ARK5 in cancer and other diseases (Review)

Malignant tumors are often exposed to hypoxic and glucose-starved microenvironments. AMP-activated protein kinase (AMPK) is an energy sensor that is stimulated during energy-deficient conditions and protects cells from hypoxic injury by regulating metabolism. AMPK-related protein kinase 5 (ARK5) is a member of the catalytic sub-unit of the AMPK family and has an important role in energy regulation and hypoxia. ARK5 is regulated by Akt and liver kinase B1 and is associated with numerous tumor-related molecules to exert the negative effects of tumors. Studies have revealed ARK5 overexpression in cases of tumor invasion and metastasis and a positive association with the degree of cancer cell malignancy, which is regarded as a key element in determining cancer prognosis. Furthermore, ARK5 downregulation improves drug sensitivity through the epithelial-mesenchymal transition pathway, indicating that it may be a potential therapeutic target. In other non-cancer conditions, ARK5 has various roles in neurodegenerative diseases (Alzheimer's and Huntington's disease), renal disorders (diabetic nephropathy and renal fibrosis) and physiological processes (striated muscle generation). In the present review, the upstream and downstream molecular pathways of ARK5 in cancer and other diseases are described and potential therapeutic strategies are discussed.

Novel Gene Signatures Predictive of Patient Recurrence-Free Survival and Castration Resistance in Prostate Cancer

Simple Summary

Molecular signatures predictive of recurrence-free survival (RFS) and castration resistance are critical for treatment decision-making in prostate cancer (PCa), but the robustness of current signatures is limited. This study aims to identify castration-resistant PCa (CRPC)-associated genes and develop robust RFS and CRPC signatures. Among 287 genes differentially expressed between localized CRPC and hormone-sensitive PCa (HSPC) samples, 6 genes constituted a signature (CRPC-derived prognosis signature, CRPCPS) that predicted RFS. Moreover, a 3-gene panel derived from the 6 CRPCPS genes was capable of distinguishing CRPC from HSPC. The CRPCPS predicted RFS in 5/9 cohorts in the multivariate analysis and maintained prognostic in patients stratified by tumor stage, Gleason score, and lymph node metastasis status. It also predicted overall survival and metastasis-free survival. Notably, the signature was validated in another six independent cohorts. These findings suggest that these two signatures could be robust tools for predicting RFS and CRPC in clinical practice.

Abstract

Molecular signatures predictive of recurrence-free survival (RFS) and castration resistance are critical for treatment decision-making in prostate cancer (PCa), but the robustness of current signatures is limited. Here, we applied the Robust Rank Aggregation (RRA) method to PCa transcriptome profiles and identified 287 genes differentially expressed between localized castration-resistant PCa (CRPC) and hormone-sensitive PCa (HSPC). Least absolute shrinkage and selection operator (LASSO) and stepwise Cox regression analyses of the 287 genes developed a 6-gene signature predictive of RFS in PCa. This signature included NPEPL1, VWF, LMO7, ALDH2, NUAK1, and TPT1, and was named CRPC-derived prognosis signature (CRPCPS). Interestingly, three of these 6 genes constituted another signature capable of distinguishing CRPC from HSPC. The CRPCPS predicted RFS in 5/9 cohorts in the multivariate analysis and remained valid in patients stratified by tumor stage, Gleason score, and lymph node status. The signature also predicted overall survival and metastasis-free survival. The signature’s robustness was demonstrated by the C-index (0.55–0.74) and the calibration plot in all nine cohorts and the 3-, 5-, and 8-year area under the receiver operating characteristic curve (0.67–0.77) in three cohorts. The nomogram analyses demonstrated CRPCPS’ clinical applicability. The CRPCPS thus appears useful for RFS prediction in PCa.

Development and Therapeutic Potential of NUAKs Inhibitors

NUAK isoforms, NUAK1 (ARK5) and NUAK2 (SNARK), are important members of the AMPK family of protein kinases. They are involved in a broad spectrum of physiological and cellular events, and sometimes their biological roles overlap. NUAK isoform dysregulation is associated with numerous pathological disorders, including neurodegeneration, metastatic cancer, and diabetes. Therefore, they are promising therapeutic targets in metabolic diseases and cancers; consequently, various NUAK-targeted inhibitors have been disclosed. The first part of this review comprises a brief discussion of the homology, expression, structure, and characteristics of NUAK isoforms. The second part focuses on NUAK isoforms' involvement in crucial biological operations, including mechanistic findings, highlighting how their abnormal functioning contributes to disease progression and quality of life. The third part summarizes the key findings and applications of targeting NUAK isoforms for treating multiple cancers and neurodegenerative disorders. The final part systematically presents a critical review and analysis of the literature on NUAK isoform inhibitions through small molecules.

AMP‑activated protein kinase family member 5 is an independent prognostic indicator of pancreatic adenocarcinoma: A study based on The Cancer Genome Atlas

Pancreatic adenocarcinoma (PAAD) is a common and highly malignant tumor. The identification of prognostic biomarkers for PAAD could provide invaluable information for clinical treatment. AMP‑activated protein kinase family member 5 (ARK5) is a member of the AMPK family that mediates the migration of PAAD cells. In the present study, ARK5 expression was evaluated using bioinformatics analysis in public datasets from The Cancer Genome Atlas. The expression levels of ARK5 in PAAD tumor tissue were significantly increased, compared with matched non‑cancerous tissues. ARK5 target genes were then predicted and Gene Ontology Biological Processes, Kyoto Encyclopedia of Genes and Genomes pathway analysis and Reactome gene sets were used to determine the functions associated with the target genes. A protein‑protein interaction network was also constructed to find out the node genes and observe their association with the overall survival rate of PAAD. A total of nine node genes were identified in the PPI network, of which six were significantly upregulated in PAAD tissue, compared with matched normal tissue. The prognostic value of each node gene was evaluated by comparing the overall survival in patients with PAAD stratified according to the expression levels of these genes. Overall survival was significantly reduced in patients with high polo‑like kinase‑1 (PLK1) or protein phosphatase 1 catalytic subunit β (PPP1CB) expression, compared with patients with low expression of these genes. To further evaluate the relationship between PAAD and ARK5, ARK5 immunohistochemical staining was performed in a tissue microarray consisting of 112 tumor samples from patients with PAAD and adjacent normal tissue samples. ARK5 protein expression in PAAD tissue was markedly increased, compared with non‑cancerous tissue (P=7.631x10‑11). Moreover, ARK5 protein levels were associated with N stage (P=0.018). The overall survival of patients with PAAD with high ARK5 protein expression levels was reduced (P=0.014), compared with patients with low expression. In conclusion, these findings suggested that ARK5 may represent an independent prognostic indicator of PAAD.

Cytosolic NUAK1 Enhances ATP Production by Maintaining Proper Glycolysis and Mitochondrial Function in Cancer Cells

NUAK1 is an AMPK-related kinase located in the cytosol and the nucleus, whose expression associates with tumor malignancy and poor patient prognosis in several cancers. Accordingly, NUAK1 was associated with metastasis because it promotes cell migration and invasion in different cancer cells. Besides, NUAK1 supports cancer cell survival under metabolic stress and maintains ATP levels in hepatocarcinoma cells, suggesting a role in energy metabolism in cancer. However, the underlying mechanism for this metabolic function, as well as its link to NUAK1 subcellular localization, is unclear. We demonstrated that cytosolic NUAK1 increases ATP levels, which associates with increased mitochondrial respiration, supporting that cytosolic NUAK1 is involved in mitochondrial function regulation in cancer cells. NUAK1 inhibition led to the formation of “donut-like” structures, providing evidence of NUAK1-dependent mitochondrial morphology regulation. Additionally, our results indicated that cytosolic NUAK1 increases the glycolytic capacity of cancer cells under mitochondrial inhibition. Nuclear NUAK1 seems to be involved in the metabolic switch to glycolysis. Altogether, our results suggest that cytosolic NUAK1 participates in mitochondrial ATP production and the maintenance of proper glycolysis in cancer cells. Our current studies support the role of NUAK1 in bioenergetics, mitochondrial homeostasis, glycolysis and metabolic capacities. They suggest different metabolic outcomes depending on its subcellular localization. The identified roles of NUAK1 in cancer metabolism provide a potential mechanism relevant for tumor progression and its association with poor patient prognosis in several cancers. Further studies could shed light on the molecular mechanisms involved in the identified metabolic NUAK1 functions.

miR-622 is a novel potential biomarker of breast carcinoma and impairs motility of breast cancer cells through targeting NUAK1 kinase

BACKGROUND

Aberrant expression of microRNAs (miR) has been proposed as non-invasive biomarkers for breast cancers. The aim of this study was to analyse the miR-622 level in the plasma and in tissues of breast cancer patients and to explore the role of miR-622 and its target, the NUAK1 kinase, in this context.

METHODS

miR-622 expression was analysed in plasma and in tissues samples of breast cancer patients by q-RT-PCR. Bioinformatics programs, luciferase assay, public dataset analysis and functional experiments were used to uncover the role of miR-622 and its target in breast cancer cells.

RESULTS

miR-622 is downregulated in plasma and in tissues of breast cancer patients respect to healthy controls and its downregulation is significantly associated with advanced grade and high Ki67 level. Modulation of miR-622 affects the motility phenotype of breast cancer cells. NUAK1 kinase is a functional target of miR-622, it is associated with poor clinical outcomes of breast cancer patients and is inversely correlated with miR-622 level.

CONCLUSIONS

miR-622/NUAK1 axis is deregulated in breast cancer patients and affects the motility phenotype of breast cancer cells. Importantly, miR-622 and NUAK1 hold promises as biomarkers and as targets for breast cancers.

Discovery of candidate gene expression signatures in peripheral blood for the screening of cervical cancer

Aim: To investigate whether cervical cancer (CC) and cervical intraepithelial neoplasia (CIN) can be screened by analyzing gene expression profiling of peripheral blood. Methods: RNA-sequencing analysis of blood was performed on 11 CC patients, 21 CIN patients and 19 healthy controls (H). Fifty-nine genes were validated by quantitative real-time PCR using blood samples from 46 H, 83 CC and 32 CIN patients. Results: There were significant differences in the expression levels of six genes between CC and H, five genes between CIN and H and four genes between CC and CIN (p < 0.05). Four genes discriminated cervical lesions from H with a sensitivity of 82.61%, a specificity of 87.83% and an area under the curve of 0.8981. Three genes discriminated CC from CIN with a sensitivity of 53.13%, a specificity of 96.39% and an area under the curve of 0.7786. Conclusion: Our findings provided a promising noninvasive quantitative real-time PCR diagnostic assay of CC and CIN.

miR-424-5p represses the metastasis and invasion of intrahepatic cholangiocarcinoma by targeting ARK5

MicroRNAs (miRNAs) have been validated to play prominent roles in the occurrence and development of many kinds of malignant cancer. MiR-424-5p has been reported to participate in various tumors proliferation and metastasis as a suppressor. On the contrary, miR-424-5p would promote cell proliferation in some tumors. However, the expression of miR-424-5p in intrahepatic cholangiocarcinoma (ICC) is rarely reported and its mechanism remains unclear. Here, we discover that miR-424-5p is frequently downregulated in ICC tissues compared with adjacent normal tissues and in ICC cells. Over-expression of miR-424-5p significantly inhibits the invasion and migration of ICC cells in vitro. Importantly, miR-424-5p is found to be a suppressor of ARK5, by binding to 3'-UTR of ARK5 mRNA and then inhibiting mTOR phosphorylated, thus deregulating epithelial-mesenchymal transition (EMT) of ICC. Furthermore, ARK5 is found to play a role in ICC metastasis and regulating EMT. Knockdown of ARK5 inhibits invasion and migration of ICC, while the over-expression gives an opposite effect. Besides, high-expression of ARK5 is also associated with poor prognosis. In conclusion, our study reveals that miR-424-5p is critical to the invasion, migration and EMT progression in ICC cells. Targeting the pathway described here may be a novel approach to inhibit metastasis of ICC and the restoration of miR-424-5p expression may be a promising strategy for ICC therapy.

The Role of MicroRNAs in Recurrence and Metastasis of Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) affects 650,000 people worldwide and has a dismal 50% 5-year survival rate. Recurrence and metastasis are believed the two most important factors causing this high mortality. Understanding the biological process and the underlying mechanisms of recurrence and metastasis is critical to develop novel and effective treatment, which is expected to improve patients' survival of HNSCC. MicroRNAs are small, non-coding nucleotides that regulate gene expression at the transcriptional and post-transcriptional level. Oncogenic and tumor-suppressive microRNAs have shown to regulate nearly every step of recurrence and metastasis, ranging from migration and invasion, epithelial-mesenchymal transition (EMT), anoikis, to gain of cancer stem cell property. This review encompasses an overview of microRNAs involved in these processes. The recent advances of utilizing microRNA as biomarkers and targets for treatment, particularly on controlling recurrence and metastasis are also reviewed.

MiR-204 inhibits hepatocellular cancer drug resistance and metastasis through targeting NUAK1

Liver cancer is a leading cause of cancer-related deaths globally. Tumor response rate of liver cancer patients towards systemic chemotherapy is low and chemoresistance can easily develop. Identifying novel molecules that can repress drug resistance and metastasis of liver cancer will facilitate the development of new therapeutic strategies. The aim of this study is to determine the roles of NUAK1 and miR-204 in the drug resistance and metastasis of liver cancer and to reveal their relationship. We found that NUAK1 was increased in the tumor of primary liver cancer. Knockdown of NUAK1 significantly inhibited cell growth and migration. Moreover, NUAK1 was the direct downstream target of miR-204, and there was clinical relevance between miR-204 down-regulation and NUAK1 up-regulation in liver cancer. Furthermore, we found that miR-204 increased drug sensitivity by down-regulating NUAK1 expression. Based on these results, we identified miR-204 as a tumor suppressor by inhibiting NUAK1 expression in liver cancer, indicating both miR-204 and NUAK1 may act as promising targets for liver cancer therapy.

Transforming growth factor β (TGFβ) induces NUAK kinase expression to fine-tune its signaling output

TGFβ signaling via SMAD proteins and protein kinase pathways up- or down-regulates the expression of many genes and thus affects physiological processes, such as differentiation, migration, cell cycle arrest, and apoptosis, during developmental or adult tissue homeostasis. We here report that NUAK family kinase 1 (NUAK1) and NUAK2 are two TGFβ target genes. NUAK1/2 belong to the AMP-activated protein kinase (AMPK) family, whose members control central and protein metabolism, polarity, and overall cellular homeostasis. We found that TGFβ-mediated transcriptional induction of NUAK1 and NUAK2 requires SMAD family members 2, 3, and 4 (SMAD2/3/4) and mitogen-activated protein kinase (MAPK) activities, which provided immediate and early signals for the transient expression of these two kinases. Genomic mapping identified an enhancer element within the first intron of the NUAK2 gene that can recruit SMAD proteins, which, when cloned, could confer induction by TGFβ. Furthermore, NUAK2 formed protein complexes with SMAD3 and the TGFβ type I receptor. Functionally, NUAK1 suppressed and NUAK2 induced TGFβ signaling. This was evident during TGFβ-induced epithelial cytostasis, mesenchymal differentiation, and myofibroblast contractility, in which NUAK1 or NUAK2 silencing enhanced or inhibited these responses, respectively. In conclusion, we have identified a bifurcating loop during TGFβ signaling, whereby transcriptional induction of NUAK1 serves as a negative checkpoint and NUAK2 induction positively contributes to signaling and terminal differentiation responses to TGFβ activity.

Functional genomics identifies specific vulnerabilities in PTEN-deficient breast cancer

Background

Phosphatase and tensin homolog (PTEN) is one of the most frequently inactivated tumor suppressors in breast cancer. While PTEN itself is not considered a druggable target, PTEN synthetic-sick or synthetic-lethal (PTEN-SSL) genes are potential drug targets in PTEN-deficient breast cancers. Therefore, with the aim of identifying potential targets for precision breast cancer therapy, we sought to discover PTEN-SSL genes present in a broad spectrum of breast cancers.

Methods

To discover broad-spectrum PTEN-SSL genes in breast cancer, we used a multi-step approach that started with (1) a genome-wide short interfering RNA (siRNA) screen of ~ 21,000 genes in a pair of isogenic human mammary epithelial cell lines, followed by (2) a short hairpin RNA (shRNA) screen of ~ 1200 genes focused on hits from the first screen in a panel of 11 breast cancer cell lines; we then determined reproducibility of hits by (3) identification of overlaps between our results and reanalyzed data from 3 independent gene-essentiality screens, and finally, for selected candidate PTEN-SSL genes we (4) confirmed PTEN-SSL activity using either drug sensitivity experiments in a panel of 19 cell lines or mutual exclusivity analysis of publicly available pan-cancer somatic mutation data.

Results

The screens (steps 1 and 2) and the reproducibility analysis (step 3) identified six candidate broad-spectrum PTEN-SSL genes (PIK3CB, ADAMTS20, AP1M2, HMMR, STK11, and NUAK1). PIK3CB was previously identified as PTEN-SSL, while the other five genes represent novel PTEN-SSL candidates. Confirmation studies (step 4) provided additional evidence that NUAK1 and STK11 have PTEN-SSL patterns of activity. Consistent with PTEN-SSL status, inhibition of the NUAK1 protein kinase by the small molecule drug HTH-01-015 selectively impaired viability in multiple PTEN-deficient breast cancer cell lines, while mutations affecting STK11 and PTEN were largely mutually exclusive across large pan-cancer data sets.

Conclusions

Six genes showed PTEN-SSL patterns of activity in a large proportion of PTEN-deficient breast cancer cell lines and are potential specific vulnerabilities in PTEN-deficient breast cancer. Furthermore, the NUAK1 PTEN-SSL vulnerability identified by RNA interference techniques can be recapitulated and exploited using the small molecule kinase inhibitor HTH-01-015. Thus, NUAK1 inhibition may be an effective strategy for precision treatment of PTEN-deficient breast tumors.

Electronic supplementary material

The online version of this article (10.1186/s13058-018-0949-3) contains supplementary material, which is available to authorized users.

Ηypoxia-inducible factor 1-α promotes colon cell proliferation and migration by upregulating AMPK-related protein kinase 5 under hypoxic conditions

Hypoxia is a common characteristic of solid tumors. Previous studies have reported that the tumor invasion-associated factor, AMPK-related protein kinase 5 (ARK5), is associated with a poor prognosis in colon cancer. However, whether or not ARK5 is involved in hypoxia is unclear. The aim of present study was to investigate the association between the expression of ARK5 and that of hypoxia-inducible factor 1-α (HIF1-α). Samples from 60 patients with colon cancer were collected and immunohistochemistry was used to detect the expression of ARK5 and HIF1-α within them. Western blot analysis and reverse transcription polymerase chain reaction were used to detect the expression of ARK5 in an SW480 cell line under hypoxic conditions. Cell Counting kit-8 and Transwell assays were used to study the function of ARK5 under hypoxic conditions. According to the immunohistochemistry results, ARK5 and HIF1-α staining was significantly associated with Tumor-Node-Metastasis stage, tumor grade, lymph node metastasis and liver metastasis. Spearman's correlation analysis revealed a correlation between the expression of ARK5 and that of HIF1-α. This finding was also verified under hypoxic conditions in the SW480 cell line, in which the expression of ARK5 increased over time. Further cellular function experiments revealed that suppression of ARK5 inhibited cell viability and migration under hypoxic conditions. The present study has suggested that ARK5 expression in colon cancer cells is upregulated by HIF1-α under hypoxic conditions and that ARK5 serves an important role in cell proliferation and migration under hypoxic stress.

ARK5 promotes invasion and migration in hepatocellular carcinoma cells by regulating epithelial-mesenchymal transition

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-associated mortality worldwide. The highly invasive nature of HCC leads to poor prognosis in patients with malignant HCC. AMPK-related protein kinase 5 (ARK5) is a key mediator of migratory activity in human cancer cells. However, the role of ARK5 in invasion and metastasis of HCC cells remains unclear. The present study attempted to determine whether ARK5 is involved in invasion and migration via regulation of epithelial-mesenchymal transition (EMT). Wound healing and Transwell Matrigel invasion assays were utilized to detect the ability of the epithelial Huh7 and mesenchymal SNU387 HCC cells to migrate and invade. Next, the expression of ARK5 and EMT markers, E-cadherin and vimentin, were examined by western blot analysis. Inhibition of ARK5 was able to significantly reduce the ability HCC cells to invade and metastasize. Furthermore, the knockdown of ARK5 was able to reverse the process of EMT in HCC cells. These data suggested that ARK5 may serve an important role in regulating EMT in HCC cells. Taken together, these findings indicate that ARK5 is a potential molecular target for the development of novel HCC therapeutics, which focus on cell invasion and EMT regulation.

Salinomycin enhances doxorubicin sensitivity through reversing the epithelial-mesenchymal transition of cholangiocarcinoma cells by regulating ARK5

Chemotherapy response rates in patients with cholangiocarcinoma remain low, primarily due to the development of drug resistance. Epithelial-mesenchymal transition (EMT) of cancer cells is widely accepted to be important for metastasis and progression, but it has also been linked to the development of chemoresistance. Salinomycin (an antibiotic) has shown some potential as a chemotherapeutic agent as it selectively kills cancer stem cells, and has been hypothesized to block the EMT process. In this study, we investigated whether salinomycin could reverse the chemoresistance of cholangiocarcinoma cells to the chemotherapy drug doxorubicin. We found that combined salinomycin with doxorubicin treatment resulted in a significant decrease in cell viability compared with doxorubicin or salinomycin treatment alone in two cholangiocarcinoma cell lines (RBE and Huh-28). The dosages of both drugs that were required to produce a cytotoxic effect decreased, indicating that these two drugs have a synergistic effect. In terms of mechanism, salinomycin reversed doxorubicin-induced EMT of cholangiocarcinoma cells, as shown morphologically and through the detection of EMT markers. Moreover, we showed that salinomycin treatment downregulated the AMP-activated protein kinase family member 5 (ARK5) expression, which regulates the EMT process of cholangiocarcinoma. Our results indicated that salinomycin reversed the EMT process in cholangiocarcinoma cells by inhibiting ARK5 expression and enhanced the chemosensitivity of cholangiocarcinoma cells to doxorubicin. Therefore, a combined treatment of salinomycin with doxorubicin could be used to enhance doxorubicin sensitivity in patients with cholangiocarcinoma.

Integration of genomic, transcriptomic and functional profiles of aggressive osteosarcomas across multiple species

In complex, highly unstable genomes such as in osteosarcoma, targeting aberrant checkpoint processes (metabolic, cell cycle or immune) may prove more successful than targeting specific kinase or growth factor signaling pathways. Here, we establish a comparative oncology approach characterizing the most lethal osteosarcomas identified in a biorepository of tumors from three different species: human, mouse and canine. We describe the development of a genetically-engineered mouse model of osteosarcoma, establishment of primary cell cultures from fatal human tumors, and a biorepository of osteosarcoma surgical specimens from pet dogs. We analyzed the DNA mutations, differential RNA expression and in vitro drug sensitivity from two phenotypically-distinct cohorts: tumors with a highly aggressive biology resulting in death from rapidly progressive, refractory metastatic disease, and tumors with a non-aggressive, curable phenotype. We identified ARK5 (AMPK-Related Protein Kinase 5, also referred to as NUAK Family Kinase 1) as a novel metabolic target present in all species, and independent analyses confirmed glucose metabolism as the most significantly aberrant cellular signaling pathway in a model system for highly metastatic tumors. Pathway integration analysis identified Polo Like Kinase 1 (PLK1)-mediated checkpoint adaptation as critical to the survival of a distinctly aggressive osteosarcoma. The tumor-associated macrophage cytokine CCL18 (C-C Motif Chemokine Ligand 18) was significantly over-expressed in aggressive human osteosarcomas, and a clustering of mutations in the BAGE (B Melanoma Antigen) tumor antigen gene family was found. The theme of these features of high risk osteosarcoma is checkpoint adaptations, which may prove both prognostic and targetable.

microRNA-203 suppresses invasion and epithelial-mesenchymal transition induction via targeting NUAK1 in head and neck cancer

Head and neck squamous cell carcinoma (HNSCC) has a high capacity for invasion. To identify microRNAs (miRNAs) that regulate HNSCC invasion, we compared miRNA expression profiles between a parent HNSCC cell line and a highly invasive clone. The miR-200 family and miR-203 were downregulated in the clone. Here we focused on the role of miR-203 in invasion and epithelial-mesenchymal transition (EMT) induction in HNSCC. miR-203 was downregulated during EMT induction. Moreover, ectopic overexpression of miR-203 suppressed the invasion and induced mesenchymal-epithelial transition (MET) in HNSCC cells. Interestingly, we identified NUAK family SNF1-like kinase 1 (NUAK1) as a novel target gene of miR-203 by cyclopedic analysis using anti-Ago2 antibody. Increased expression of NUAK1 was observed during EMT induction, and ectopic expression of miR-203 delayed EMT induction by suppressing NUAK1 expression. Moreover, NUAK1 overexpression promoted the invasion of HNSCC cells. Importantly, NUAK1 expression was well correlated with poor differentiation, invasiveness, and lymph node metastasis in HNSCC cases. Overall, miR-203 has a tumor-suppressing role in invasion and EMT induction by targeting NUAK1 in HNSCC, suggesting miR-203 as a potential new diagnostic and therapeutic target for the treatment of HNSCC.

Activation of ARK5/miR-1181/HOXA10 axis promotes epithelial-mesenchymal transition in ovarian cancer

Epithelial ovarian cancer (EOC) is the sixth most common cancer in females worldwide and, although advances have been made in the detection, diagnosis and therapies for EOC, it remains the most lethal gynecologic malignancy in advanced countries. Nevertheless, relatively little is known concerning the molecular events that lead to the development of this highly aggressive disease. Elucidating the molecular mechanism involved in this disease may prove useful to understand the pathogenesis and progression of the disease, and to identify new targets for effective therapies. In the present study, we examined the role of ARK5 in ovarian cancer and normal matched tissues using western blot analysis and migration and invasion, and wound‑healing assays. The results showed that ARK5 was upregulated in ovarian cancer tissues, compared with adjacent normal tissues. Moreover, it promoted epithelial‑mesenchymal transition (EMT) and inhibited miR-1181 expression in ovarian cancer cells. Subsequent investigations showed that miR-1181 promoted mesenchymal-epithelial transition (MET) in ovarian cancer cells. Downstream target genes of miR-1181 were searched, and it was identified that miR-1181 degraded HOXA10 by targeting its 3' untranslated region (3'UTR) in ovarian cancer cells. The results confirmed that HOXA10 promoted EMT in ovarian cancer cells. Thus, activation of the ARK5/miR-1181/HOXA10 axis may be positively associated with EMT in ovarian cancer.

MiR-204 inhibits human NSCLC metastasis through suppression of NUAK1

BACKGROUND

Lung cancer is a leading cause of cancer-related mortality worldwide and non-small-cell lung carcinoma (NSCLC) is responsible for almost 80% of lung cancer-related deaths. Identifying novel molecules that can repress the invasiveness and metastasis of lung cancer will facilitate the development of new antilung cancer strategies. The aim of this study is to determine the roles of NUAK1 (a downstream of Akt) and miR-204 in the invasiveness and metastasis of NSCLC and to reveal the correlation between NUAK1 and miR-204.

METHODS

The expression of NUAK1 in primary human NSCLC tissues was evaluated by immunohistochemistry. Real-time PCR was employed to measure the expression level of miR-204. The effect of NUAK1 and miR204 on the prognosis of NSCLC patients was evaluated by log-rank test. The siRNA transfection was used to manipulate the expression levels of NUAK1 and miR204 in cancer cells. Chemotaxis assay, Scratch assay, and Matrigel invasion assay were performed to evaluate the migration and invasion of cells. Cellular F-actin measurement was used to measure F-actin polymerisation in lung cancer cells. Western blot was used to detect the expression levels of corresponding proteins. The Luciferase assay and RNA immunoprecipitation were used to confirm the actual binding site of miR-204 to 3'UTR of NUAK1.

RESULTS

Increased expression of NUAK1 is correlated with the invasiveness and metastasis of human NSCLC. Knockdown of NUAK1 inhibited cell migration and invasion. In addition, this study showed that NUAK1 influenced mTOR phosphorylation and induced the phosphorylation of p70S6K1 and eukaryotic initiation factor 4E-binding protein1 (4E-BP1), two downstream targets of mTOR in NSCLC cells. At the same time, decreased expression of miR-204 promoted NSCLC progression and, contrarily, manipulated upregulation of miR-204-inhibited cell migration and invasion. There is clinical relevance between miR-204 downregulation and NUAK1 upregulation in human NSCLC. Furthermore, we found that miR-204 inhibited NSCLC tumour invasion by directly targeting and downregulating NUAK1 expression. Finally, our data suggested that the downregulation of miR-204 was due to hypermethylation of its promoter region.

CONCLUSIONS

Our results indicate that NUAK1 is excessively expressed in NSCLC and plays important roles in NSCLC invasion. The miR-204 acts as a tumour suppressor by inhibiting NUAK1 expression in NSCLC. Both NUAK1 and miR-204 may serve as potential targets of NSCLC therapy.

Rewiring of an epithelial differentiation factor, miR-203, to inhibit human squamous cell carcinoma metastasis

Metastatic colonization of distant organs underpins the majority of human-cancer-related deaths, including deaths from head and neck squamous cell carcinoma (HNSCC). We report that miR-203, a miRNA that triggers differentiation in multilayered epithelia, inhibits multiple postextravasation events during HNSCC lung metastasis. Inducible reactivation of miR-203 in already established lung metastases reduces the overall metastatic burden. Using an integrated approach, we reveal that miR-203 inhibits metastasis independently of its effects on differentiation. In vivo genetic reconstitution experiments show that miR-203 inhibits lung metastasis by suppressing the prometastatic activities of three factors involved in cytoskeletal dynamics (LASP1), extracellular matrix remodeling (SPARC), and cell metabolism (NUAK1). Expression of miR-203 and its downstream effectors correlates with HNSCC overall survival outcomes, indicating the therapeutic potential of targeting this signaling axis.

miR‑96 functions as a tumor suppressor gene by targeting NUAK1 in pancreatic cancer

microRNA-96 (miR-96) is known to be downregulated in pancreatic cancer. The overexpression of miR-96 in MIA PaCa-2 pancreatic cancer cells has been shown to inhibit cell proliferation, migration and invasion; however, the mechanisms involved have not yet been fully elucidated. Novel (nua) kinase family 1 (NUAK1) functions as an oncogene in non‑small cell lung cancer (NSCLC), melanoma, glioma, breast cancer, hepatocellular carcinoma and pancreatic cancer. In this study, firstly, we demonstrate that NUAK1 expression is specifically upregulated in pancreatic cancer and that it promotes the proliferation, migration and invasion of MIA PaCa-2 pancreatic cancer cells. Secondly, we performed an analysis of potential microRNA (miRNA) target sites using three commonly used prediction algorithms: miRanda, TargetScan and PicTar. All three algorithms predicted that miR-96 targets the 3' untranslated region (3' UTR) of NUAK1. Further experiments confirmed this prediction, namely that miR-96 suppresses the expression of NUAK1 by targeting its 3' UTR. Finally, we demonstrate that the introduction of NUAK1 cDNA lacking predicted sites of the 3' UTR abrogates miR-96 cellular function.