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

NUAK: never underestimate a kinase

NUAK1 and NUAK2 belong to a family of kinases related to the catalytic α-subunits of the AMP-activated protein kinase (AMPK) complexes. Despite canonical activation by the tumour suppressor kinase LKB1, both NUAKs exhibit a spectrum of activities that favour tumour development and progression. Here, we review similarities in structure and function of the NUAKs, their regulation at gene, transcript and protein level, and discuss their phosphorylation of specific downstream targets in the context of the signal transduction pathways and biological activities regulated by each or both NUAKs.

NUAK1 coordinates growth factor-dependent activation of mTORC2 and Akt signaling

BACKGROUND

mTORC2 is a critical regulator of cytoskeleton organization, cell proliferation, and cancer cell survival. Activated mTORC2 induces maximal activation of Akt by phosphorylation of Ser-473, but regulation of Akt activity and signaling crosstalk upon growth factor stimulation are still unclear.

RESULTS

We identified that NUAK1 regulates growth factor-dependent activation of Akt by two mechanisms. NUAK1 interacts with mTORC2 components and regulates mTORC2-dependent activation of Akt by controlling lysosome positioning and mTOR association with this organelle. A second mechanism involves NUAK1 directly phosphorylating Akt at Ser-473. The effect of NUAK1 correlated with a growth factor-dependent activation of specific Akt substrates. NUAK1 induced the Akt-dependent phosphorylation of FOXO1/3a (Thr-24/Thr-32) but not of TSC2 (Thr-1462). According to a subcellular compartmentalization that could explain NUAK1's differential effect on the Akt substrates, we found that NUAK1 is associated with early endosomes but not with plasma membrane, late endosomes, or lysosomes. NUAK1 was required for the Akt/FOXO1/3a axis, regulating p21CIP1, p27KIP1, and FoxM1 expression and cancer cell survival upon EGFR stimulation. Pharmacological inhibition of NUAK1 potentiated the cell death effect induced by Akt or mTOR pharmacological blockage. Analysis of human tissue data revealed that NUAK1 expression positively correlates with EGFR expression and Akt Ser-473 phosphorylation in several human cancers.

CONCLUSIONS

Our results showed that NUAK1 kinase controls mTOR subcellular localization and induces Akt phosphorylation, demonstrating that NUAK1 regulates the growth factor-dependent activation of Akt signaling. Therefore, targeting NUAK1, or co-targeting it with Akt or mTOR inhibitors, may be effective in cancers with hyperactivated Akt signaling.

Functional and Potential Therapeutic Implication of MicroRNAs in Pancreatic Cancer

The alarmingly low five-year survival rate for pancreatic cancer presents a global health challenge, contributing to about 7% of all cancer-related deaths. Late-stage diagnosis and high heterogeneity are the biggest hurdles in treating pancreatic cancer. Thus, there is a pressing need to discover novel biomarkers that could help in early detection as well as improve therapeutic strategies. MicroRNAs (miRNAs), a class of short non-coding RNA, have emerged as promising candidates with regard to both diagnostics and therapeutics. Dysregulated miRNAs play pivotal roles in accelerating tumor growth and metastasis, orchestrating tumor microenvironment, and conferring chemoresistance in pancreatic cancer. The differential expression profiles of miRNAs in pancreatic cancer could be utilized to explore novel therapeutic strategies. In this review, we also covered studies on recent advancements in various miRNA-based therapeutics such as restoring miRNAs with a tumor-suppressive function, suppressing miRNA with an oncogenic function, and combination with chemotherapeutic drugs. Despite several challenges in terms of specificity and targeted delivery, miRNA-based therapies hold the potential to revolutionize the treatment of pancreatic cancer by simultaneously targeting multiple signaling pathways.

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.

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.

MiR-96-5p induced NDRG1 deficiency promotes prostate cancer migration and invasion through regulating the NF-κB signaling pathway

OBJECTIVE: The N-myc downstream-regulated gene 1 (NDRG1) has been discovered as a significant gene in the progression of cancers. However, the regulatory mechanism of NDRG1 remained obscure in prostate cancer (PCa). METHODS: The miR-96-5p and NDRG1 expression levels were evaluated in PCa cell lines, prostate tissues, and validated public databases by real-time PCR, western blot analysis, and immunohistochemistry. The function of miR-96-5p and NDRG1 were investigated by wound healing and transwell assays in vitro, and mouse xenograft assay in vivo. The candidate pathway regulated by NDRG1 was conducted by the next-generation gene sequencing technique. Immunofluorescence and luciferase assay was used to detect the relation between miR-96-5p, NDRG1, and NF-kB pathway. RESULTS: Overexpressing NDRG1 suppresses the migration, invasion, and epithelial-mesenchymal transition (EMT) in vitro, and inhibits metastasis in vivo. Moreover, miR-96-5p contributes to NDRG1 deficiency and promotes PCa cell migration and invasion. Furthermore, NDRG1 loss activates the NF-KB pathway, which stimulates p65 and IKBa phosphorylation and induces EMT in PCa. CONCLUSIONS: MiR-96-5p promotes the migration and invasion of PCa by targeting NDRG1 and regulating the NF-κB pathway.

Oncogenomic Changes in Pancreatic Cancer and Their Detection in Stool

Pancreatic cancer (PC) is an aggressive malignancy with a dismal prognosis. To improve patient survival, the development of screening methods for early diagnosis is pivotal. Oncogenomic alterations present in tumor tissue are a suitable target for non-invasive screening efforts, as they can be detected in tumor-derived cells, cell-free nucleic acids, and extracellular vesicles, which are present in several body fluids. Since stool is an easily accessible source, which enables convenient and cost-effective sampling, it could be utilized for the screening of these traces. Herein, we explore the various oncogenomic changes that have been detected in PC tissue, such as chromosomal aberrations, mutations in driver genes, epigenetic alterations, and differentially expressed non-coding RNA. In addition, we briefly look into the role of altered gut microbiota in PC and their possible associations with oncogenomic changes. We also review the findings of genomic alterations in stool of PC patients, and the potentials and challenges of their future use for the development of stool screening tools, including the possible combination of genomic and microbiota markers.

Identification of microRNA-96-5p as a postoperative, prognostic microRNA predictor in nonviral hepatocellular carcinoma

AIM

The microRNA (miR) clusters miR-183/96/182 and miR-217/216a/216b are significantly upregulated in nonviral hepatocellular carcinoma (NBNC-HCC). Here, we investigate the impact of each member of these clusters on the clinical outcome of NBNC-HCC and analyze the antitumor effects of miR-96-5p.

METHODS

The association between recurrence-free survival of 111 NBNC-HCC patients and the levels of miR-183-5p, miR-96-5p, miR-182-5p, miR-217-5p, miR-216a-5p, and miR-216b-5p in tumor and adjacent tissues was investigated. The impact of miR-96-5p on apoptosis and invasion of a hepatoma cell line, HepG2, was investigated by cell counting, Transwell assay, and flow cytometry, respectively.

RESULTS

MicroRNA-183-5p, miR-96-5p, miR-182-5p, miR-217-5p, and miR-216b-5p were significantly upregulated in tumor tissues compared to the adjacent tissues (p = 0.0005, p = 0.0030, p = 0.0002, p = 0.0011, and p = 0.0288, respectively). By multivariate Cox regression analysis, high tumor/adjacent ratios of miR-182-5p (p = 0.007) and miR-217-5p (p = 0.008) were associated with poor recurrence-free survival. In contrast, a low tumor/adjacent ratio of miR-96-5p (p < 0.001) was associated with poor recurrence-free survival. It suggested that further upregulation of miR-96-5p in tumors might have an inhibitory effect on recurrence. Transfection of miR-96-5p mimic significantly induced apoptosis of HepG2 cells, in association with downregulation of Nucleophosmin 1 (NPM1) and a decrease of phosphorylated AKT protein. Interestingly, simultaneous knockdown of the NPM1 and AKT genes induced apoptosis. MicroRNA-96-5p also suppressed proliferation and invasion, which inhibited epithelial-to-mesenchymal transition of HCC cells.

CONCLUSION

MicroRNA-96-5p as a tumor suppressor would be valuable to stratify NBNC-HCC patients at high risk of recurrence.

MicroRNA-96: A therapeutic and diagnostic tumor marker

Cancer has been always considered as one of the main human health challenges worldwide. One of the main causes of cancer-related mortality is late diagnosis in the advanced stages of the disease, which reduces the therapeutic efficiency. Therefore, novel non-invasive diagnostic methods are required for the early detection of tumors and improving the quality of life and survival in cancer patients. MicroRNAs (miRNAs) have pivotal roles in various cellular processes such as cell proliferation, motility, and neoplastic transformation. Since circulating miRNAs have high stability in body fluids, they can be suggested as efficient noninvasive tumor markers. MiR-96 belongs to the miR-183-96-182 cluster that regulates cell migration and tumor progression as an oncogene or tumor suppressor by targeting various genes in solid tumors. In the present review, we have summarized all of the studies that assessed the role of miR-96 during tumor progression. This review clarifies the molecular mechanisms and target genes recruited by miR-96 to regulate tumor progression and metastasis. It was observed that miR-96 mainly affects tumorigenesis by targeting the structural proteins and FOXO transcription factors.

Nuclear Transport Factor 2 (NTF2) suppresses WM983B metastatic melanoma by modifying cell migration, metastasis, and gene expression

While changes in nuclear structure and organization are frequently observed in cancer cells, relatively little is known about how nuclear architecture impacts cancer progression and pathology. To begin to address this question, we studied Nuclear Transport Factor 2 (NTF2) because its levels decrease during melanoma progression. We show that increasing NTF2 expression in WM983B metastatic melanoma cells reduces cell proliferation and motility while increasing apoptosis. We also demonstrate that increasing NTF2 expression in these cells significantly inhibits metastasis and prolongs survival of mice. NTF2 levels affect the expression and nuclear positioning of a number of genes associated with cell proliferation and migration, and increasing NTF2 expression leads to changes in nuclear size, nuclear lamin A levels, and chromatin organization. Thus, ectopic expression of NTF2 in WM983B metastatic melanoma abrogates phenotypes associated with advanced stage cancer both in vitro and in vivo, concomitantly altering nuclear and chromatin structure and generating a gene expression profile with characteristics of primary melanoma. We propose that NTF2 is a melanoma tumor suppressor and could be a novel therapeutic target to improve health outcomes of melanoma patients.

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.

Suppressing the KIF20A/NUAK1/Nrf2/GPX4 signaling pathway induces ferroptosis and enhances the sensitivity of colorectal cancer to oxaliplatin

Oxaliplatin resistance can develop in colorectal cancer (CRC), which may involve inhibition of ferroptosis, although further research is needed to understand this potential mechanism. We evaluated CRC cells with acquired oxaliplatin resistance (HCT116-Or) or congenital resistance (H716) to determine whether a ferroptosis inducer (RSL3) or inhibitor (liproxstatin-1) could modulate the effects of oxaliplatin. The results suggested that induction of ferroptosis could significantly reverse the oxaliplatin resistance of the CRC cells. Bioinformatic and cytobiological searches also revealed that KIF20A was highly expressed in the oxaliplatin-resistant cell lines and was strongly correlated with survival among CRC patients. Silencing KIF20A enhanced cellular sensitivity to oxaliplatin both in vivo and in vitro, and silencing KIF20A also suppressed NUAK1 activation, while a NUAK1 agonist (ETC-1002) could reverse the oxaliplatin sensitivity of KIF20A-silenced cells. Moreover, silencing NUAK1 up-regulated the expression of PP1β, down-regulated the phosphorylation of downstream GSK3βSer9, suppressed the nuclear import of Nrf2, inhibited the expression of a ferroptosis key negative regulatory protein (GPX4), and blocked cellular resistance. Applying a Nrf2 agonist (oltipraz) also reversed the oxaliplatin sensitivity of NUAK1-silenced cells. Therefore, cellular ferroptosis may be inhibited via the KIF20A/NUAK1/PP1β/GPX4 pathway in CRC cells, which may underly the resistance of CRC to oxaliplatin.

MicroRNA-1182 and let-7a exert synergistic inhibition on invasion, migration and autophagy of cholangiocarcinoma cells through down-regulation of NUAK1

Background

Cholangiocarcinoma (CCA) is the second most common primary liver malignancy worldwide. Several microRNAs (miRNAs) have been implicated as potential tumor suppressors in CCA. This study aims to explore the potential effects of miR-1182 and let-7a on CCA development.

Methods

Bioinformatics analysis was conducted to screen differentially expressed genes in CCA, Western blot analysis detected NUAK1 protein expression and RT-qPCR detected miR-1182, let-7a and NUAK1 expression in CCA tissues and cell lines. Dual luciferase reporter gene assay and RIP were applied to validate the relationship between miR-1182 and NUAK1 as well as between let-7a and NUAK1. Functional experiment was conducted to investigate the role of miR-1182, let-7a and NUAK1 in cell migration, proliferation and autophagy. Then, the CCA cells that received various treatments were implanted to mice to establish animal model, followed by tumor observation and HE staining to evaluate lung metastasis.

Results

CCA tissues and cells were observed to have a high expression of NUAK1 and poor expression of miR-1182 and let-7a. NUAK1 was indicated as a target gene of miR-1182 and let-7a. Importantly, upregulation of either miR-1182 or let-7a induced autophagy, and inhibited cell progression and in vivo tumor growth and lung metastasis; moreover, combined treatment of miR-1182 and let-7a overexpression presented with enhanced inhibitory effect on NUAK1 expression and CCA progression, but such synergistic effect could be reversed by overexpression of NUAK1.

Conclusion

Taken together, the findings suggest the presence of a synergistic antitumor effect of miR-1182 and let-7a on the development of CCA via the down-regulation of NUAK1, providing novel insight into the targeted therapy against CCA.

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.

LncRNA MALAT1 promotes breast cancer progression and doxorubicin resistance via regulating miR-570–3p

Background

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a long non-coding RNA (lncRNA) that regulates disease progression in various types of cancers. The aim of this study was to explore the role of MALAT1 in breast cancer (BC) progression and doxorubicin resistance.

Methods

Real-time polymerase chain reaction (RT-PCR) was used to determine the expression of MALAT1 in BC tissues and cells; MTT and Transwell assay were used to detect the proliferation, migration and invasion of BC cells, respectively; drug resistance test was performed to assess the sensitivity of BC cells to doxorubicin; dual-luciferase reporter gene assay was conducted to verify the interaction between MALAT1 and miR-570–3p.

Results

MALAT1 was highly expressed in BC tissues compared with normal tissues adjacent to cancer as well as in BC cells. In addition, inhibition the expression of MALAT1 could significantly suppress the proliferation, migration and invasion of BC cells. Meanwhile, down-regulation of MALAT1 sensitized BC cells to doxorubicin. Moreover, bioinformatics analysis suggested that miR-570–3p was the potential downstream target of MALAT1. Dual-luciferase reporter gene assay confirmed that MALAT1 could directly target miR-570–3p. Additionally, miR-570–3p was lowly expressed in BC tissues and cells. Up-regulation of miR-570–3p not only significantly inhibited the proliferation, metastasis, and invasion of BC cells, but also increased the sensitivity of BC cells to doxorubicin.

Conclusion

MALAT1 functions as a novel oncogenic lncRNA in regulating the progression and doxorubicin resistance of BC by targeting miR-570–3p.

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.

KRAS-associated microRNAs in colorectal cancer

Colorectal cancer (CRC) is one of the leading causes of cancerrelated death worldwide. Despite progress in treatment of cancers, CRC with KRAS mutations are resistant towards anti-EGFR treatment. MicroRNAs have been discovered in an exponential manner within the last few years and have been known to exert either an onco-miRNA or tumor suppressive effect. Here, the various roles of microRNAs involved in the initiation and progression of KRAS-regulated CRC are summarized. A thorough understanding of the roles and functions of the plethora of microRNAs associated with KRAS in CRC will grant insights into the provision of other potential therapeutic targets as well as treatment. MicroRNAs may also serve as potential molecular classifier or early detection biomarkers for future treatment and diagnosis of CRC.

miR-96-5p regulated TGF-β/SMAD signaling pathway and suppressed endometrial cell viability and migration via targeting TGFBR1

We previously performed high throughput RNA-seq in paired eutopic and ectopic endometrial specimen of endometriosis patients, and validated the results by qRT-PCR in endometriosis endometrial tissues. MiR-96-5p was significantly downregulated in ectopic endometrial tissues compared to eutopic tissues. In order to identify the role of miR-96-5p in endometriosis and endometrial cells, and investigate the underlying mechanisms, the Ishikawa and End1/E6E7 cell lines were transfected with miR-96-5p mimics, miR-96-5p inhibitors or TGFBR1 siRNA. The expression of TGF-β/SMAD signaling pathway components and epithelial-mesenchymal transition (EMT) markers were examined by qRT-PCR and western blot, and cell viability and migration were determined by CCK-8, transwell and wound healing assays, respectively. We discovered miR-96-5p to be significantly downregulated while TGFBR1 was distinctly up-regulated in endometriosis. Overexpression of miR-96-5p inhibited endometrial cells viability and migration, while inhibition of miR-96-5p had opposite effect. Furthermore, we confirmed TGFBR1 was a direct target of miR-96-5p. Overexpression of miR-96-5p could block the TGF-β/SMAD signaling pathway via targeting TGFBR1 and reverse the TGF-β1 induced EMT in endometrial cell lines. In conclusion, we demonstrated that miR-96-5p interacted with TGF-β/SMAD signaling pathway and blocked the TGF-β1 induced EMT in endometrial cells via directly targeting TGFBR1.

Implication of hsa_circ_0028007 in reinforcing migration, invasion, and chemo-tolerance of nasopharyngeal carcinoma cells

Background

Given the reliability of circRNAs in symbolizing cancer progression, this investigation was designed to expound the involvement of hsa_circ_0028007 in regulating chemosensitivity of nasopharyngeal carcinoma (NPC) cells.

Methods

Altogether, 241 pairs of NPC tissues and para‐cancerous normal tissues were collected to identify NPC‐symbolic circRNAs, which have been screened by circRNA microarray in advance. Expressions of the circRNAs were determined by means of real‐time polymerase chain reaction (PCR). Besides, human NPC cell lines (ie, CNE2 and HONE1) were transfected by si‐hsa_circ_0028007 and si‐NC. Scratch assay, transwell assay, and MTT assay were performed to assess migration, invasion, and paclitaxel/cisplatin‐resistance of NPC cell lines.

Results

Hsa_circ_0028007 expression was abnormally heightened within NPC tissues in comparison with matched non‐tumor tissues (P < .05). Over‐expressed hsa_circ_0028007 was strongly associated with advanced (III‐IV) tumor stage, aggressive infiltration, and metastatic lymph nodes of NPC patients (P < .05). Regarding in vitro experiments, hsa_circ_0028007 expression was elevated in CNE2 and HONE1 cell lines as compared with HENE cell line (P < .05). Silencing of hsa_circ_0028007 not merely sensitized CNE2 and HONE1 cells against paclitaxel and cisplatin (P < .05), but also significantly repressed migration and invasion of the cell lines (P < .05).

Conclusion

Hsa_circ_0028007 was involved in facilitating progression and chemo‐resistance of NPC, which might offer an alternative for NPC treatment.

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.

MicroRNA and mRNA Interaction Network Regulates the Malignant Transformation of Human Bronchial Epithelial Cells Induced by Cigarette Smoke

This study analyzes the correlation and interaction of miRNAs and mRNAs and their biological function in the malignant transformation of BEAS-2B cells induced by cigarette smoke (CS). Normal human bronchial epithelial cells (BEAS-2B) were continuously exposed to CS for 30 passages (S30) to establish an in vitro cell model of malignant transformation. The transformed cells were validated by scratch wound healing assay, transwell migration assay, colony formation and tumorigenicity assay. The miRNA and mRNA sequencing analysis were performed to identify differentially expressed miRNAs (DEMs) and differentially expressed genes (DEGs) between normal BEAS-2B and S30 cells. The miRNA-seq data of lung cancer with corresponding clinical data obtained from TCGA was used to further identify lung cancer-related DEMs and their correlations with smoking history. The target genes of these DEMs were predicted using the miRDB database, and their functions were analyzed using the online tool “Metascape.” It was found that the migration ability, colony formation rate and tumorigenicity of S30 cells enhanced. A total of 42 miRNAs and 753 mRNAs were dysregulated in S30 cells. The change of expression of top five DEGs and DEMs were consistent with our sequencing results. Among these DEMs, eight miRNAs were found dysregulated in lung cancer tissues based on TCGA data. In these eight miRNAs, six of them including miR-96-5p, miR-93-5p, miR-106-5p, miR-190a-5p, miR-195-5p, and miR-1-3p, were found to be associated with smoking history. Several DEGs, including THBS1, FN1, PIK3R1, CSF1, CORO2B, and PREX1, were involved in many biological processes by enrichment analysis of miRNA and mRNA interaction. We identified the negatively regulated miRNA-mRNA pairs in the CS-induced lung cancer, which were implicated in several cancer-related (especially EMT-related) biological process and KEGG pathways in the malignant transformation progress of lung cells induced by CS. Our result demonstrated the dysregulation of miRNA-mRNA profiles in cigarette smoke-induced malignant transformed cells, suggesting that these miRNAs might contribute to cigarette smoke-induced lung cancer. These genes may serve as biomarkers for predicting lung cancer pathogenesis and progression. They can also be targets of novel anticancer drug development.

MicroRNA-96 is a potential tumor repressor by inhibiting NPTX2 in renal cell carcinoma

MicroRNA-96 (miR-96) is a vertebrate conserved microRNA which plays important roles in various cancers including renal cell carcinoma (RCC). However, its function and mechanism in RCC are still unclear. In this study, miR-96 was found to be downregulated in RCC based on The Cancer Genome Atlas datasets analyses, and its target genes, which predicted by TargetScan, were investigated. Among these target genes, neuronal pentraxin 2 (NPTX2) was upregulated more than 15-fold in RCC, and moreover, closely related to patient survival. To validate its targeting of NPTX2 experimentally, reverse transcription polymerase chain reaction, Western blot analysis, and dual-luciferase assays were performed, and results of these assays demonstrated that miR-96 inhibited expression of NPTX2 through a single 3'-untranslated region targeting site. Furthermore, transfection assays in RenCa and 786-O cells showed miR-96 and small interfering RNA of NPTX2 inhibited cell proliferation, migration, and invasion and overexpression of NPTX2 recovered the inhibition of miR-96. In conclusion, the present study reveals a novel regulatory mechanism of miR-96 on NPTX2 expression in RCC, and the potential of miR-96 as a RCC tumor repressor deserves further investigation.

Inhibition of miR31 and miR92a as Oncological Biomarkers in RKO Colon Cancer Cells Treated with Kaempferol-3-O-Glycoside Isolated from Black Bean

MicroRNAs (miRNAs) are small molecules of 19-23 nucleotides of RNA that act as regulators of the expression of proteins in eukaryotic cells. Currently, the participation of miRNAs in the development of different types of cancer has been observed. To evaluate the inhibitory effect of kaempferol-3-O-glycoside on the expression of oncological biomarkers, miR31 and miR92a in a colon cancer cell line (RKO) were analyzed. Cells were cultured and treated with 1 mM kaempferol-3-O-glycoside isolated from black bean. Expression levels of miR31 and miR92a were evaluated by real-time PCR using TaqMan probes; in addition, two oncogenes (KRAS and c-MYC) and two tumor suppressors (AMP-activated protein kinase [AMPK] and adenomatous tumors of polyposis coli [APC]) were quantified to validate the biological effects; normalization of expression levels were carried out by 2^-ΔΔCt. Results were analyzed by one-way ANOVA. The expression levels of miR31, miR92a, KRAS oncogene, and the c-MYC transcription factor were subexpressed upon 72 h post-treatment with kaempferol-3-O-glycoside compared with the control without treatment (P < .05); in contrast, the tumor suppressor genes AMPK (∼4.85, P = .005) and APC (∼2.71, P = .066) tumor suppressors genes were overexpressed. Our results showed the inhibitory effect of isolated black bean flavonoid kaempferol-3-O-glycoside on cancer biomarkers: miR31 and miR92a; based on our results, this flavonoid may have interesting nutritional, therapeutic, and/or prophylactic applications to combat colon cancer.

miR-96-5p targets PTEN expression affecting radio-chemosensitivity of HNSCC cells

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is the sixth leading cancer worldwide. They are typically characterized by a high incidence of local recurrence, which is the most common cause of death in HNSCC patients. TP53 is the most frequently mutated gene in HNSCC and patients carrying TP53 mutations are associated with a higher probability to develop local recurrence. MiRNAs, which are among the mediators of the oncogenic activity of mt-p53 protein, emerge as an appealing tool for screening, diagnosis and prognosis of cancer. We previously identified a signature of 12 miRNAs whose aberrant expression associated with TP53 mutations and was prognostic for HNSCC. Among them miR-96-5p emerges as an oncogenic miRNAs with prognostic significance in HNSCC.

METHODS

To evaluate the oncogenic role of miR-96-5p in a tumoral context, we performed colony formation, cell migration and cell viability assays in two HNSCC cell lines transfected for miR-96-5p mimic or inhibitor and treated with or without radio/chemo-therapy. In addition, to identify genes positively and negatively correlated to miR-96-5p expression in HNSCC, we analyzed the correlation between gene expression and miR-96-5p level in the subset of TCGA HNSCC tumors carrying missense TP53 mutations by Spearman and Pearson correlation. To finally identify targets of miR-96-5p, we used in silico analysis and the luciferase reporter assay to confirm PTEN as direct target.

RESULTS

Our data showed that overexpression of miR-96-5p led to increased cell migration and radio-resistance, chemotherapy resistance in HNSCC cells. In agreement with these results, among the most statistically significant pathways in which miR-96-5p is involved, are focal Adhesion, extracellular matrix organization and PI3K-Akt-mTOR-signaling pathway. As a direct target of miR-96-5p, we identified PTEN, the main negative regulator of PI3K-Akt signalling pathway activation.

CONCLUSIONS

These results highlight a new mechanism of chemo/radio-resistance insurgence in HNSCC cells and support the possibility that miR-96-5p expression could be used as a novel promising biomarker to predict radiotherapy response and local recurrence development in HNSCC patients. In addition, the identification of pathways in which miR-96-5p is involved could contribute to develop new therapeutic strategies to overcome radio-resistance.

Identification and functional analysis of microRNAs in rats following focal cerebral ischemia injury

MicroRNA sequencing (miRNA‑seq) was performed in the present study to investigate miRNA expression profiles in infarcted brain areas following focal cerebral ischemia induced by middle cerebral artery occlusion in rats. In total, 20 miRNAs were identified to be upregulated and 17 to be downregulated in the infarct area. The expression levels of six differentially expressed miRNAs (DEmiRs), miR‑211‑5p, miR‑183‑5p, miR‑10b‑3p, miR‑182, miR‑217‑5p and miR‑96‑5p, were examined by reverse transcription‑​quantitative polymerase chain reaction. Subsequently, a miRNA‑mRNA network was constructed. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed to investigate the functions of the mRNAs targeted by these DEmiRs. The present study aimed to investigate the association between miRNAs and cerebral ischemia to provide potential insight into the molecular mechanisms underlying ischemic stroke.

miR-96 regulates migration and invasion of bladder cancer through epithelial-mesenchymal transition in response to transforming growth factor-β1

Bladder cancer (BC) is one of the most frequent urological malignancies, and its molecular mechanism still remains unclear. Recent studies have revealed that MicroRNA (miRNAs) acted as oncogenes or tumor suppressors in a variety of cancers. MiRNA-96 has been reported to play a significant role in the development and progression of many cancers. In the current study, we found that transforming growth factor (TGF)-β1 played a significant role in the progression that miR-96 conducted. And TGF-β1 could also regulate the expression of FOXQ1, which is the target gene of miR-96. Furthermore, miR-96 induced epithelial-mesenchymal transition in BC cells, which is driven by TGF-β1. In conclusion, our data revealed that miR-96 regulates the progression and epithelial-mesenchymal transition, which is driven by TGF-β1 in BC cells; it may provide a new thought for the therapy of BC.

Expression of miRNAs Targeting mTOR and S6K1 Genes of mTOR Signaling Pathway Including miR-96, miR-557, and miR-3182 in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a highly aggressive form of breast cancer. Aberrant expression of genes in mTOR pathway and their targeting miRNAs plays an important role in TNBC. The aim of this study was to determine the expression of mTOR and S6K1 and their targeting miRNAs in breast cancer cell lines and clinical samples. miRNAs targeting 3'-UTR of mTOR and S6K1 mRNAs were predicted using bioinformatic algorithms. MDA-MB-231, MCF-7, and MCF-10A as well as 20 TNBC samples were analyzed for gene and miRNA expression using quantitative real-time PCR (RT-qPCR). A receiver operating characteristic (ROC) curve analysis was performed for evaluation of candidate miRNAs as diagnostic biomarkers. miR-96 and miR-557 targeting mTOR and S6K1 mRNAs, respectively, were selected, and miR-3182 was selected as the miRNA targeting both genes. The miRNAs were down-regulated in cell lines, while their target mRNAs were up-regulated. Similar findings were observed in clinical samples. The ROC curve analysis revealed decline in expression of these miRNAs. We suggest that miR-96, miR-557, and miR-3182 can be used as inhibitory agents for mTOR and S6K1 in TNBC-targeted therapy.

LncRNA UCA1 impacts cell proliferation, invasion, and migration of pancreatic cancer through regulating miR-96/FOXO3

This study was expected to reveal the regulatory effects of lncRNA UCA1 on pancreatic cancer cell progression through targeting miR-96/FOXO3. Microarray analysis was carried out on 36 cases of pancreatic cancer tissues and 16 cases of adjacent tissues among them. Expression levels of lncRNA UCA1, miR-96, and FOXO3 in pancreatic cancer tissues and cell lines were determined by qRT-PCR. Expression levels of FOXO3 protein were determined by western blot. Cell viability, cell cycle and apoptosis, cell invasion and migration were detected by CCK-8, flow cytometry, and transwell assay, respectively. The colocalization relationship between lncRNA UCA1 and miR-96 was detected by RNA FISH. Whether UCA1 could target miR-96 and whether miR-96 could target FOXO3 3'UTR were verified by dual-luciferase reporter gene assay. High expression of lncRNA UCA1 and FOXO3 and low expression of miR-96 were shown in pancreatic cancer. Inhibition of UCA1 suppressed pancreatic tumor cell proliferation, colony formation, and metastasis, while inhibition of miR-96 promoted pancreatic cancer cell progression. FOXO3 was the downstream target gene of miR-96 and showed the opposite effects. LncRNA UCA1 promoted cell proliferation, invasion, migration and inhibited cell apoptosis of pancreatic cancer through down-regulating miR-96 and up-regulating FOXO3. © 2018 IUBMB Life, 70(4):276-290, 2018.

LncRNA SNHG1 functions as a ceRNA to antagonize the effect of miR-145a-5p on the down-regulation of NUAK1 in nasopharyngeal carcinoma cell

How lncRNA SNHG1 influences the aggressiveness of nasopharyngeal carcinoma cells as well as the underlying mechanism was studied. The lncRNA differences were analysed by GSE12452 gene microarray. The expression of SNHG1, MiR‐145‐5p and NUAK1 was identified by qRT‐PCR and western blot. Transfection was conducted to construct nasopharyngeal carcinoma cells with different expressions of SNHG1, miR‐145‐5p and NUAK1. Dual‐luciferase reporter assay was performed to explore the relationship between SNHG1, miR‐145‐5p and NUAK1. Wound‐healing assay and transwell invasion experiments were employed to study changes in cell migration capacity and cell invasion, respectively. Tumour xenografts were performed to observe lung metastasis of nude mice inoculated with transfected CNE cells. SNHG1 is highly expressed in nasopharyngeal carcinoma tissues and in cell lines. Down‐regulation of SNHG1 facilitated the expression of miR‐145‐5p and further suppressed the level of NAUK1 in CNE and HNE‐1 cells. Silencing of SNHG1, up‐regulation of miR‐145‐5p and inhibition of NAUK1 by relative transfection all attenuated the aggressiveness of CNE and HNE‐1 cells both in vivo and in vitro. Moreover, the impaired cell migration and invasion by SNHG1 siRNA could be rescued by cotransfection of miR‐145‐5p in CNE and HNE‐1 cells. LncRNA SNHG1 promoted the expression of NUAK1 by down‐regulating miR‐145‐5p and thus promoted the aggressiveness of nasopharyngeal carcinoma cells through AKT signalling pathway and induced epithelial‐mesenchymal transition (EMT).

Calcium signalling links MYC to NUAK1

NUAK1 is a member of the AMPK-related family of kinases. Recent evidence suggests that NUAK1 is an important regulator of cell adhesion and migration, cellular and organismal metabolism, and regulation of TAU stability. As such, NUAK1 may play key roles in multiple diseases ranging from neurodegeneration to diabetes and metastatic cancer. Previous work revealed a crucial role for NUAK1 in supporting viability of tumour cells specifically when MYC is overexpressed. This role is surprising, given that NUAK1 is activated by the tumour suppressor LKB1. Here we show that, in tumour cells lacking LKB1, NUAK1 activity is maintained by an alternative pathway involving calcium-dependent activation of PKCα. Calcium/PKCα-dependent activation of NUAK1 supports engagement of the AMPK-TORC1 metabolic checkpoint, thereby protecting tumour cells from MYC-driven cell death, and indeed, MYC selects for this pathway in part via transcriptional regulation of PKCα and ITPR. Our data point to a novel role for calcium in supporting tumour cell viability and clarify the synthetic lethal interaction between NUAK1 and MYC.

MicroRNA-21 versus microRNA-34: Lung cancer promoting and inhibitory microRNAs analysed in silico and in vitro and their clinical impact

MicroRNAs are well-known strong RNA regulators modulating whole functional units in complex signaling networks. Regarding clinical application, they have potential as biomarkers for prognosis, diagnosis, and therapy. In this review, we focus on two microRNAs centrally involved in lung cancer progression. MicroRNA-21 promotes and microRNA-34 inhibits cancer progression. We elucidate here involved pathways and imbed these antagonistic microRNAs in a network of interactions, stressing their cancer microRNA biology, followed by experimental and bioinformatics analysis of such microRNAs and their targets. This background is then illuminated from a clinical perspective on microRNA-21 and microRNA-34 as general examples for the complex microRNA biology in lung cancer and its diagnostic value. Moreover, we discuss the immense potential that microRNAs such as microRNA-21 and microRNA-34 imply by their broad regulatory effects. These should be explored for novel therapeutic strategies in the clinic.

Identification and characterization of miR-96, a potential biomarker of NSCLC, through bioinformatic analysis

Lung cancer is the leading cause of cancer-related death worldwide. The poor prognosis is partly due to lack of efficient methods for early diagnosis. MicroRNAs play roles in almost all aspects of cancer biology, and can be secreted into the circulation and serve as molecular biomarkers for the early diagnosis of cancer. In the present study, we determined the expression of miR-96 and the function of its target genes in lung cancer through bioinformatic analysis. Four microRNA expression profiles of lung cancer were downloaded from Gene Expression Omnibus and the data were analyzed using SPSS 16.0 software. Compared to the control group, expression of miR-96 was significantly increased in non-small cell lung cancer (NSCLC) (GSE51855), lung adenocarcinoma (GSE48414), stage I adenocarcinoma tissues (GSE63805) and the plasma of lung cancer patients (GSE68951). miR-96 was also elevated in six different NSCLC cell lines. However, the expression level of miR-96 was not related to the age, gender, clinical stage and histological subtype of the NSCLC patients. GO analysis of 78 predicted target genes of miR-96 showed that 42 of the obtained GO terms are highly associated with specific cellular processes including response to stimulus, signaling pathway, cell division, cell communication, cell migration and calcium signaling. KEGG results indicated that the miR-96 targets are mainly involved in the GnRH signaling pathway, long-term potentiation and insulin signaling pathway. In conclusion, miR-96, functioning as an oncogene, may play an important role in the development and progression of lung cancer. miR-96 may have the potential to serve as a molecular biomarker for the early diagnosis of NSCLC.

Structure-Based Target-Specific Screening Leads to Small-Molecule CaMKII Inhibitors

Target-specific scoring methods are more commonly used to identify small-molecule inhibitors among compounds docked to a target of interest. Top candidates that emerge from these methods have rarely been tested for activity and specificity across a family of proteins. In this study we docked a chemical library into CaMKIIδ, a member of the Ca2+ /calmodulin (CaM)-dependent protein kinase (CaMK) family, and re-scored the resulting protein-compound structures using Support Vector Machine SPecific (SVMSP), a target-specific method that we developed previously. Among the 35 selected candidates, three hits were identified, such as quinazoline compound 1 (KIN-1; N4-[7-chloro-2-[(E)-styryl]quinazolin-4-yl]-N1,N1-diethylpentane-1,4-diamine), which was found to inhibit CaMKIIδ kinase activity at single-digit micromolar IC50 . Activity across the kinome was assessed by profiling analogues of 1, namely 6 (KIN-236; N4-[7-chloro-2-[(E)-2-(2-chloro-4,5-dimethoxyphenyl)vinyl]quinazolin-4-yl]-N1,N1-diethylpentane-1,4-diamine), and an analogue of hit compound 2 (KIN-15; 2-[4-[(E)-[(5-bromobenzofuran-2-carbonyl)hydrazono]methyl]-2-chloro-6-methoxyphenoxy]acetic acid), namely 14 (KIN-332; N-[(E)-[4-(2-anilino-2-oxoethoxy)-3-chlorophenyl]methyleneamino]benzofuran-2-carboxamide), against 337 kinases. Interestingly, for compound 6, CaMKIIδ and homologue CaMKIIγ were among the top ten targets. Among the top 25 targets of 6, IC50 values ranged from 5 to 22 μm. Compound 14 was found to be not specific toward CaMKII kinases, but it does inhibit two kinases with sub-micromolar IC50 values among the top 25. Derivatives of 1 were tested against several kinases including several members of the CaMK family. These data afforded a limited structure-activity relationship study. Molecular dynamics simulations with explicit solvent followed by end-point MM-GBSA free-energy calculations revealed strong engagement of specific residues within the ATP binding pocket, and also changes in the dynamics as a result of binding. This work suggests that target-specific scoring approaches such as SVMSP may hold promise for the identification of small-molecule kinase inhibitors that exhibit some level of specificity toward the target of interest across a large number of proteins.

Local microRNA delivery targets Palladin and prevents metastatic breast cancer

Metastasis is the primary cause for mortality in breast cancer. MicroRNAs, gene expression master regulators, constitute an attractive candidate to control metastasis. Here we show that breast cancer metastasis can be prevented by miR-96 or miR-182 treatment, and decipher the mechanism of action. We found that miR-96/miR-182 downregulate Palladin protein levels, thereby reducing breast cancer cell migration and invasion. A common SNP, rs1071738, at the miR-96/miR-182-binding site within the Palladin 3'-UTR abolishes miRNA:mRNA binding, thus diminishing Palladin regulation by these miRNAs. Regulation is successfully restored by applying complimentary miRNAs. A hydrogel-embedded, gold-nanoparticle-based delivery vehicle provides efficient local, selective, and sustained release of miR-96/miR-182, markedly suppressing metastasis in a breast cancer mouse model. Combined delivery of the miRNAs with a chemotherapy drug, cisplatin, enables significant primary tumour shrinkage and metastasis prevention. Our data corroborate the role of miRNAs in metastasis, and suggest miR-96/miR-182 delivery as a potential anti-metastatic drug.

MicroRNA-183 suppresses cancer stem-like cell properties in EBV-associated nasopharyngeal carcinoma

BACKGROUND

Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus (EBV)-associated epithelial malignancy that exhibits distinct geographical and ethnic prevalence. Although the contemporary therapeutic approach of radio-/chemotherapy provides excellent results for patients with early-stage disease, it is far from satisfactory for those with disease remission and distant metastasis. Promising therapeutic strategies for advanced and relapsed NPC are still lacking. We recently identified and characterized a cancer stem-like cell (CSC) subpopulation in NPC that appeared to play an important role in tumor progression. Microarray analysis revealed downregulation of several stemness-inhibiting miRNAs in these CSC cells. Among these miRNAs, miR-96 and miR-183 showed the highest fold change and were selected to elucidate their role in repressing NPC CSC properties.

METHODS

MiR-96 and miR-183 expression in NPC CSCs was detected by qRT-PCR. Transient and stable transfection was performed in EBV-positive NPC C666-1 cells to examine the effects of ectopic expression of miR-96 and miR-183 on repressing cell growth and CSC properties. Anchorage-dependent (colony formation) and anchorage-independent (tumor sphere formation) growths of these miR-96 and miR-183 expressing cells were determined. Expression of multiple CSC markers and related molecules were accessed by flow cytometry and Western blotting. The tumorigenicity of the stable miR-96- and miR-183-transfected NPC cells was examined in an in vivo nude mice model.

RESULTS

Downregulation of miR-96 and miR-183 was confirmed in NPC spheroids. Using transient or stable transfection, we showed that ectopic expression of miR-96 and miR-183 suppressed cell growth and tumor sphere formation in NPC. Reduced NICD3 and NICD4 in miR-96- and miR-183-expressing NPC cells suggests the involvement of the NOTCH signaling pathway in their tumor suppressive function. Finally, we showed that the tumorigenicity of cells stably expressing miR-183 was significantly inhibited in the in vivo nude mice model.

CONCLUSIONS

miR-183 is a tumor-suppressive miRNA in EBV-associated NPC. Its abilities to suppress CSC properties in vitro and effectively reduce tumor growth in vivo shed light on its role as a potential therapeutic target.

The miRacle in Pancreatic Cancer by miRNAs: Tiny Angels or Devils in Disease Progression

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with increasing incidence and high mortality. Surgical resection is the only potentially curative treatment of patients with PDAC. Because of the late presentation of the disease, about 20 percent of patients are candidates for this treatment. The average survival of resected patients is between 12 and 20 months, with a high probability of relapse. Standard chemo and radiation therapies do not offer significant improvement of the survival of these patients. Furthermore, novel treatment options aimed at targeting oncogenes or growth factors in pancreatic cancer have proved unsuccessful. Thereby, identifying new biomarkers that can detect early stages of this disease is of critical importance. Among these biomarkers, microRNAs (miRNAs) have supplied a profitable recourse and become an attractive focus of research in PDAC. MiRNAs regulate many genes involved in the development of PDAC through mRNA degradation or translation inhibition. The possibility of intervention in the molecular mechanisms of miRNAs regulation could begin a new generation of PDAC therapies. This review summarizes the reports describing miRNAs involvement in cellular processes involving pancreatic carcinogenesis and their utility in diagnosis, survival and therapeutic potential in pancreatic cancer.

Mmu-miR-1894-3p Inhibits Cell Proliferation and Migration of Breast Cancer Cells by Targeting Trim46

Breast cancer is the second leading cause of cancer death in women and the presence of metastasis significantly decreases survival. MicroRNAs are involved in tumor progression and the metastatic spreading of breast cancer. Here, we reported that a microRNA, mmu-miR-1894, significantly decreased the lung metastasis of 4TO7 mouse breast cancer cells by 86.7% in mouse models. Mmu-miR-1894-3p was the functional mature form of miR-1894 and significantly decreased the lung metastasis of 4TO7 cells by 90.8% in mouse models. A dual-luciferase reporter assay indicated that mmu-miR-1894-3p directly targeted the tripartite motif containing 46 (Trim46) 3'-untranslated region (UTR) and downregulated the expression of Trim46 in 4TO7 cells. Consistent with the effect of mmu-miR-1894-3p, knockdown of Trim46 inhibited the experimental lung metastasis of 4TO7 cells. Moreover, knockdown of human Trim46 also prohibited the cell proliferation, migration and wound healing of MBA-MD-231 human breast cancer cells. These results suggested that the effect of knockdown of Trim46 alone was sufficient to recapitulate the effect of mmu-miR-1894 on the metastasis of the breast cancer cells in mouse and that Trim46 was involved in the proliferation and migration of mouse and human breast cancer cells.

MicroRNAs as biomarkers and prospective therapeutic targets in colon and pancreatic cancers

Colon and pancreatic cancers have high mortality rates due to early metastasis prior to the onset of symptoms. Screening tests for colorectal cancer are invasive and expensive. No effective screening is available for pancreatic cancer. Identification of biomarkers for early detection in both of these cancers is being extensively researched. MicroRNAs (miRNA) are small non-coding molecule biomarkers that regulate cancers. Measurement of miRNAs in pancreatic fluid or blood could be a preferred non-invasive screening method. The regulation of colon and pancreatic cancers by miRNA is complex. miRNA play a central role in inflammation, invasiveness, and tumor progression in these two cancers, as well as regulation of the NF-κB pathway. miRNA's evolving role in screening is also reviewed.

microRNA-218 suppresses the proliferation, invasion and promotes apoptosis of pancreatic cancer cells by targeting HMGB1

OBJECTIVE

To detect the expression profiles of microRNA-218 (miR-218) in human pancreatic cancer tissue (PCT) and cells and their effects on the biological features of human pancreatic cancer cell line PANC-1 and observe the effect of miR-218 on the expression of the target gene high mobility group box 1 (HMGB1), with an attempt to provide new treatment methods and strategies for pancreatic cancer.

METHODS

The expressions of miR-218 in PCT and normal pancreas tissue as well as in various pancreatic cancer cell lines including AsPC-1, BxPC-3, and PANC-1 were determined with quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). The change of miR-218 expression in PANC-1 cells was detected using qRT-PCT after the transfection of miR-218 mimic for 48 h. Cell Counting Kit-8 (CCK-8) was applied for detecting the effect of miR-218 on the activity of PANC-1 cells. The effects of miR-218 on the proliferation and apoptosis of PANC-1 cells were analyzed using the flow cytometry. The effect of miR-218 on the migration of PANC-1 cells was detected using the Trans-well migration assay. The HMGB1 was found to be a target gene of miR-218 by luciferase reporter assay, and the effect of miR-218 on the expression of HMGB1 protein in cells were determined using Western blotting.

RESULTS

As shown by qRT-PCR, the expressions of miR-218 in PCT and in pancreatic cancer cell line significantly decreased when compared with the normal pancreatic tissue (NPT) (P<0.01). Compared with the control group, the miR-218 expression significantly increased in the PANC-1 group after the transfection of miR-218 mimic for 48 h (P<0.01). Growth curve showed that the cell viability significantly dropped after the overexpression of miR-218 in the PANC-1 cells for two days (P<0.05). Flow cytometry showed that the S-phase fraction significantly dropped after the overexpression of miR-218 (P<0.01) and the percentage of apoptotic cells significantly increased (P<0.01). As shown by the Trans-well migration assay, the enhanced miR-218 expression was associated with a significantly lower number of cells that passed through a Transwell chamber (P<0.01). Luciferase reporter assay showed that, compared with the control group, the relative luciferase activity significantly decreased in the miR-218 mimic group (P<0.01). As shown by the Western blotting, compared with the control group, the HMGB1 protein expression significantly decreased in the PANC-1 group after the transfection of miR-218 mimic for 48 h (P<0.01).

CONCLUSIONS

The miR-218 expression decreases in human PCT and cell lines. miR-218 can negatively regulate the HMGB1 protein expression and inhibit the proliferation and invasion of pancreatic cancer cells. A treatment strategy by enhancing the miR-218 expression may benefit the patients with pancreatic cancer.

MicroRNA-218 inhibits the proliferation and metastasis of esophageal squamous cell carcinoma cells by targeting BMI1

MicroRNAs (miRNAs or miRs) play a pivotal role in esophageal carcinogenesis either as oncogenes or as tumor suppressor genes. In the present study, we found that the expression level of miR-218 was significantly reduced in esophageal squamous cell carcinoma (ESCC) tissues and ESCC cell lines. Moreover, its expression was found to correlate with the clinicopathological stage of ESCC; miR-218 expression was lower in the stage III tissue samples than in the stage I and II tissue samples. Furthermore, the decreased expression of miR-218 was found to be associated with an enhanced ESCC cell proliferation and metastasis. Western blot analysis and luciferase reporter assay revealed that miR-218 decreased BMI1 expression by binding to the putative binding sites in its 3′-untranslated region (3′-UTR). The BMI1 mRNA expression levels were markedly increased and negatively correlated with the miR-218 expression level in the ESCC tissues. Functional analyses revealed that the restoration of miR-218 expression inhibited ESCC cell proliferation, migration and invasion and promoted apoptosis. The knockdown of BMI1 by siRNA showed the same phenocopy as the effect of miR-218 on ESCC cells, indicating that BMI1 was a major target of miR-218. In the present study, our findings confirm miR-218 as a tumor suppressor and identify BMI1 as a novel target of miR-218 in ESCC. Therefore, miR-218 may prove to be a useful biomarker for monitoring the initiation and development of ESCC, and may thus be an effective therapeutic target in ESCC.

Endoplasmic reticulum stress-activated cell reprogramming in oncogenesis

Stress induced by the accumulation of unfolded proteins in the endoplasmic reticulum (ER) is observed in many human diseases, including cancers. Cellular adaptation to ER stress is mediated by the unfolded protein response (UPR), which aims at restoring ER homeostasis. The UPR has emerged as a major pathway in remodeling cancer gene expression, thereby either preventing cell transformation or providing an advantage to transformed cells. UPR sensors are highly regulated by the formation of dynamic protein scaffolds, leading to integrated reprogramming of the cells. Herein, we describe the regulatory mechanisms underlying UPR signaling upon cell intrinsic or extrinsic challenges, and how they engage cell transformation programs and/or provide advantages to cancer cells, leading to enhanced aggressiveness or chemoresistance. We discuss the emerging cross-talk between the UPR and related metabolic processes to ensure maintenance of protein homeostasis and its impact on cell transformation and tumor growth.

SIGNIFICANCE

ER stress signaling is dysregulated in many forms of cancer and contributes to tumor growth as a survival factor, in addition to modulating other disease-associated processes, including cell migration, cell transformation, and angiogenesis. Evidence for targeting the ER stress signaling pathway as an anticancer strategy is compelling, and novel agents that selectively inhibit the UPR have demonstrated preliminary evidence of preclinical efficacy with an acceptable safety profile.