Genome-wide methylation profiling of Peripheral T-cell lymphomas identifies TRIP13 as a critical driver of tumor proliferation and survival

Cytosine methylation of genomic DNA contributes to the regulation of gene expression and is involved in normal development including hematopoiesis in mammals. It is catalyzed by the family of DNA methyltransferases (DNMTs) that include DNMT1, DNMT3A, and DNMT3B. Peripheral T-cell lymphomas (PTCLs) represent a diverse group of aggressive mature T-cell malignancies accounting for approximately 10-15% of non-Hodgkin lymphoma cases in the US. PTCLs exhibit a broad spectrum of clinical, histological, and immunophenotypic features with poor prognosis and inadequately understood molecular pathobiology. To better understand the molecular landscape and identify candidate genes involved in disease maintenance, we used high-resolution Whole Genome Bisulfite Sequencing (WGBS) and RNA-seq to profile DNA methylation and gene expression of PTCLs and normal T-cells. We found that the methylation patterns in PTCLs are deregulated and heterogeneous but share 767 hypo- and 567 hypermethylated differentially methylated regions (DMRs) along with 231 genes up- and 91 genes downregulated in all samples suggesting a potential association with tumor development. We further identified 39 hypomethylated promoters associated with increased gene expression in the majority of PTCLs. This putative oncogenic signature included the TRIP13 (thyroid hormone receptor interactor 13) gene whose both genetic and pharmacologic inactivation, inhibited cellular growth of PTCL cell lines by inducing G2-M arrest accompanied by apoptosis suggesting that such an approach might be beneficial in human lymphoma treatment. Altogether we show that human PTCLs are characterized by a large number of recurrent methylation alterations, and demonstrated that TRIP13 is critical for PTCL maintenance in vitro .

Cyclin-dependent kinases: Masters of the eukaryotic universe

A family of structurally related cyclin-dependent protein kinases (CDKs) drives many aspects of eukaryotic cell function. Much of the literature in this area has considered individual members of this family to act primarily either as regulators of the cell cycle, the context in which CDKs were first discovered, or as regulators of transcription. Until recently, CDK7 was the only clear example of a CDK that functions in both processes. However, new data points to several "cell-cycle" CDKs having important roles in transcription and some "transcriptional" CDKs having cell cycle-related targets. For example, novel functions in transcription have been demonstrated for the archetypal cell cycle regulator CDK1. The increasing evidence of the overlap between these two CDK types suggests that they might play a critical role in coordinating the two processes. Here we review the canonical functions of cell-cycle and transcriptional CDKs, and provide an update on how these kinases collaborate to perform important cellular functions. We also provide a brief overview of how dysregulation of CDKs contributes to carcinogenesis, and possible treatment avenues. This article is categorized under: RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes RNA Processing > 3' End Processing RNA Processing > Splicing Regulation/Alternative Splicing.

O-GlcNAcylation in cancer development and immunotherapy

O-linked β-D-N-acetylglucosamine (O-GlcNAc), as a posttranslational modification (PTM), is a reversible reaction that attaches β-N-GlcNAc to Ser/Thr residues on specific proteins by O-GlcNAc transferase (OGT). O-GlcNAcase (OGA) removes the O-GlcNAc from O-GlcNAcylated proteins. O-GlcNAcylation regulates numerous cellular processes, including signal transduction, the cell cycle, metabolism, and energy homeostasis. Dysregulation of O-GlcNAcylation contributes to the development of various diseases, including cancers. Accumulating evidence has revealed that higher expression levels of OGT and hyper-O-GlcNAcylation are detected in many cancer types and governs glucose metabolism, proliferation, metastasis, invasion, angiogenesis, migration and drug resistance. In this review, we describe the biological functions and molecular mechanisms of OGT- or O-GlcNAcylation-mediated tumorigenesis. Moreover, we discuss the potential role of O-GlcNAcylation in tumor immunotherapy. Furthermore, we highlight that compounds can target O-GlcNAcylation by regulating OGT to suppress oncogenesis. Taken together, targeting protein O-GlcNAcylation might be a promising strategy for the treatment of human malignancies.

miR-1-3p Inhibits Osteosarcoma Cell Proliferation and Cell Cycle Progression While Promoting Cell Apoptosis by Targeting CDK14 to Inactivate Wnt/Beta-Catenin Signaling

Osteosarcoma (OS) is a common bone malignancy and is diagnosed frequently in children and young adults. According to previous RNA sequencing, miR-1-3p is downregulated in OS clinical samples. Nevertheless, the functions of miR-1-3p in OS cell process and the related mechanism have not been revealed yet. In the current study, miR-1-3p expression in OS tissues and cells were evaluated using quantitative polymerase chain reaction. CCK-8 assays were conducted to measure OS cell viability in response to miR-1-3p overexpression. Colony forming assays and EdU staining were conducted for measurement of cell proliferation, and flow cytometry analysis was performed to determine cell apoptosis and cell cycle progression. Protein levels of apoptotic markers, beta-catenin, and Wnt downstream targets were quantified using western blotting. The binding relation between miR-1-3p and cyclin dependent kinase 14 (CDK14) was validated utilizing luciferase reporter assays. Experimental results revealed that miR-1-3p expression was decreased in OS tissues and cells. Additionally, miR-1-3p inhibited cell proliferation and cell cycle progression while enhancing OS cell apoptosis. Moreover, miR-1-3p directly targeted CDK14 and inversely regulated CDK14 expression in OS cells. Furthermore, miR-1-3p inactivated the Wnt/beta-catenin signaling. CDK14 overexpression partially rescued the inhibitory impact of miR-1-3p on OS cell growth. Overall, miR-1-3p inhibits OS cell proliferation and cell cycle progression while promoting cell apoptosis by targeting CDK14 and inactivating the Wnt/beta-catenin signaling.

Regulatory role of miRNAs on Wnt/β-catenin signaling in tumorigenesis of glioblastoma

Glioblastoma (GBM) is one of the most aggressive tumors in the brain with high mortality worldwide. Despite recent advances in therapeutic strategies, the survival rate remains low in patients with GBM. The pathogenesis of GBM is a very complicated process involving various genetic mutations affecting several oncogenic signaling pathways like Wnt/β-catenin axis. Overactivation of the Wnt/β-catenin signaling pathway is associated with decreased survival and poor prognosis in patients with GBM. MicroRNAs (miRNAs) were shown to play important roles in the regulation of cell proliferation, differentiation, apoptosis, and tumorigenesis by modulating the expression of their target genes. Aberrant expression of miRNAs were reported in various human malignancies including GBM, breast, colorectal, liver, and prostate cancers, but little is known about their cellular mechanisms. Therefore, recognition of the expression profile and regulatory effects of miRNAs on the Wnt/β-catenin pathway may offer a novel approach for the classification, diagnosis, prognosis, and treatment of patients with GBM. This review summarizes previous data on the modulatory role of miRNAs on the Wnt/β-catenin pathway implicated in tumorigenesis of GBM.

Genome-wide screening and identification of potential kinases involved in endoplasmic reticulum stress responses

AIM

This study aims to identify endoplasmic reticulum stress response elements (ERSE) in the human genome to explore potentially regulated genes, including kinases and transcription factors, involved in the endoplasmic reticulum (ER) stress and its related diseases.

MATERIALS AND METHODS

Python-based whole genome screening of ERSE was performed using the Amazon Web Services elastic computing system. The Kinome database was used to filter out the kinases from the extracted list of ERSE-related genes. Additionally, network analysis and genome enrichment were achieved using NDEx, the Network and Data Exchange software, and web-based computational tools. To validate the gene expression, quantitative RT-PCR was performed for selected kinases from the list by exposing the HeLa cells to tunicamycin and brefeldin, ER stress inducers, for various time points.

KEY FINDINGS

The overall number of ERSE-associated genes follows a similar pattern in humans, mice, and rats, demonstrating the ERSE's conservation in mammals. A total of 2705 ERSE sequences were discovered in the human genome (GRCh38.p14), from which we identified 36 kinases encoding genes. Gene expression analysis has shown a significant change in the expression of selected genes under ER stress conditions in HeLa cells, supporting our finding.

SIGNIFICANCE

In this study, we have introduced a rapid method using Amazon cloud-based services for genome-wide screening of ERSE sequences from both positive and negative strands, which covers the entire genome reference sequences. Approximately 10 % of human protein-protein interactomes were found to be associated with ERSE-related genes. Our study also provides a rich resource of human ER stress-response-based protein networks and transcription factor interactions and a reference point for future research aiming at targeted therapeutics.

Emerging approaches to CDK inhibitor development, a structural perspective

Aberrant activity of the cyclin-dependent kinase family is frequently noted in a number of diseases identifying them as potential targets for drug development. However, current CDK inhibitors lack specificity owing to the high sequence and structural conservation of the ATP binding cleft across family members, highlighting the necessity of finding novel modes of CDK inhibition. The wealth of structural information regarding CDK assemblies and inhibitor complexes derived from X-ray crystallographic studies has been recently complemented through the use of cryo-electron microscopy. These recent advances have provided insights into the functional roles and regulatory mechanisms of CDKs and their interaction partners. This review explores the conformational malleability of the CDK subunit, the importance of SLiM recognition sites in CDK complexes, the progress made in chemically induced CDK degradation and how these studies can contribute to CDK inhibitor design. Additionally, fragment-based drug discovery can be utilised to identify small molecules that bind to allosteric sites on the CDK surface employing interactions which mimic those of native protein-protein interactions. These recent structural advances in CDK inhibitor mechanisms and in chemical probes which do not occupy the orthosteric ATP binding site can provide important insights for targeted CDK therapies.

CDK14 inhibition reduces mammary stem cell activity and suppresses triple negative breast cancer progression

The Wnt/β-catenin signaling pathway plays an important role in regulating mammary organogenesis and oncogenesis. However, therapeutic methods targeting the Wnt pathway against breast cancer have been limited. To address this challenge, we investigate the function of cyclin-dependent kinase 14 (CDK14), a member of the Wnt signaling pathway, in mammary development and breast cancer progression. We show that CDK14 is expressed in the mammary basal layer and elevated in triple negative breast cancer (TNBC). CDK14 knockdown reduces the colony-formation ability and regeneration capacity of mammary basal cells and inhibits the progression of murine MMTV-Wnt-1 basal-like mammary tumor. CDK14 knockdown or pharmacological inhibition by FMF-04-159-2 suppresses the progression and metastasis of TNBC. Mechanistically, CDK14 inhibition inhibits mammary regeneration and TNBC progression by attenuating Wnt/β-catenin signaling. These findings highlight the significance of CDK14 in mammary development and TNBC progression, shedding light on CDK14 as a promising therapeutic target for TNBC.

Wnt signaling in colorectal cancer: pathogenic role and therapeutic target

Background

The Wnt signaling pathway is a complex network of protein interactions that functions most commonly in embryonic development and cancer, but is also involved in normal physiological processes in adults. The canonical Wnt signaling pathway regulates cell pluripotency and determines the differentiation fate of cells during development. The canonical Wnt signaling pathway (also known as the Wnt/β-catenin signaling pathway) is a recognized driver of colon cancer and one of the most representative signaling pathways. As a functional effector molecule of Wnt signaling, the modification and degradation of β-catenin are key events in the Wnt signaling pathway and the development and progression of colon cancer. Therefore, the Wnt signaling pathway plays an important role in the pathogenesis of diseases, especially the pathogenesis of colorectal cancer (CRC).

Objective

Inhibit the Wnt signaling pathway to explore the therapeutic targets of colorectal cancer.

Methods

Based on studying the Wnt pathway, master the biochemical processes related to the Wnt pathway, and analyze the relevant targets when drugs or inhibitors act on the Wnt pathway, to clarify the medication ideas of drugs or inhibitors for the treatment of diseases, especially colorectal cancer.

Results

Wnt signaling pathways include: Wnt/β-catenin or canonical Wnt signaling pathway, planar cell polarity (Wnt-PCP) pathway and Wnt-Ca²⁺ signaling pathway. The Wnt signaling pathway is closely related to cancer cell proliferation, stemness, apoptosis, autophagy, metabolism, inflammation and immunization, microenvironment, resistance, ion channel, heterogeneity, EMT/migration/invasion/metastasis. Drugs/phytochemicals and molecular preparations for the Wnt pathway of CRC treatment have now been developed. Wnt inhibitors are also commonly used clinically for the treatment of CRC.

Conclusion

The development of drugs/phytochemicals and molecular inhibitors targeting the Wnt pathway can effectively treat colorectal cancer clinically.

CDK16 promotes the progression and metastasis of triple-negative breast cancer by phosphorylating PRC1

Background

Cyclin-dependent kinase 16 (CDK16) is an atypical PCTAIRE kinase, and its activity is dependent on the Cyclin Y (CCNY) family. Ccnys have been reported to regulate mammary stem cell activity and mammary gland development, and CCNY has been recognized as an oncoprotein in various cancers, including breast cancer. However, it remains unclear whether CDK16 has a role in breast cancer and whether it can be used as a therapeutic target for breast cancer.

Methods

Publicly available breast cancer datasets analyses and Kaplan-Meier survival analyses were performed to reveal the expression and clinical relevance of atypical CDKs in breast cancer. CDK16 protein expression was further examined by immunohistochemical and immunoblot analyses of clinical samples. Cell proliferation was measured by colony formation and MTT analyses. Cell cycle and apoptosis were examined by fluorescence-activated cell sorting (FACS) analysis. Wound-healing and trans-well invasion assays were conducted to test cell migration ability. The functions of CDK16 on tumorigenesis and metastasis were evaluated by cell line-derived xenograft, patient-derived organoid/xenograft, lung metastasis and systemic metastasis mouse models. Transcriptomic analysis was performed to reveal the potential molecular mechanisms involved in the function of CDK16. Pharmacological inhibition of CDK16 was achieved by the small molecular inhibitor rebastinib to further assess the anti-tumor utility of targeting CDK16.

Results

CDK16 is highly expressed in breast cancer, particularly in triple-negative breast cancer (TNBC). The elevated CDK16 expression is correlated with poor outcomes in breast cancer patients. CDK16 can improve the proliferation and migration ability of TNBC cells in vitro, and promote tumor growth and metastasis of TNBC in vivo. Both genetic knockdown and pharmacological inhibition of CDK16 significantly suppress the tumor progression of TNBC. Mechanistically, CDK16 exerts its function by phosphorylating protein regulator of cytokinesis 1 (PRC1) to regulate spindle formation during mitosis.

Conclusion

CDK16 plays a critical role in TNBC and is a novel promising therapeutic target for TNBC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-022-02362-w.

Amygdala DCX and blood Cdk14 are implicated as cross-species indicators of individual differences in fear, extinction, and resilience to trauma exposure

Doublecortin (DCX) has long been implicated in, and employed as a marker for, neurogenesis, yet little is known about its function in non-neurogenic brain regions, including the amygdala. This study sought first to explore, in rodents, whether fear learning and extinction modulate amygdala DCX expression and, second, to assess the utility of peripheral DCX correlates as predictive biomarkers of trauma response in rodents and humans. Pavlovian conditioning was found to alter DCX protein levels in mice 24 h later, resulting in higher DCX expression associated with enhanced learning in paradigms examining both the acquisition and extinction of fear (p < 0.001). This, in turn, is associated with differences in freezing on subsequent fear expression tests, and the same relationship between DCX and fear extinction was replicated in rats (p < 0.001), with higher amygdala DCX levels associated with more rapid extinction of fear. RNAseq of amygdala and blood from mice identified 388 amygdala genes that correlated with DCX (q < 0.001) and which gene ontology analyses revealed were significantly over-represented for neurodevelopmental processes. In blood, DCX-correlated genes included the Wnt signaling molecule Cdk14 which was found to predict freezing during both fear acquisition (p < 0.05) and brief extinction protocols (p < 0.001). High Cdk14 measured in blood immediately after testing was also associated with less freezing during fear expression testing (p < 0.01). Finally, in humans, Cdk14 expression in blood taken shortly after trauma was found to predict resilience in males for up to a year post-trauma (p < 0.0001). These data implicate amygdala DCX in fear learning and suggest that Cdk14 may serve as a predictive biomarker of trauma response.

Hypoxia associated lncRNA HYPAL promotes proliferation of gastric cancer as ceRNA by sponging miR-431-5p to upregulate CDK14

Gastric cancer (GC) is a common malignant solid tumor that is characterized by high hypoxia. The transcription of genes associated with hypoxia affects tumor occurrence and development. Long non-coding RNAs (lncRNAs) have been reported to play important roles in cancer development. In this study, we screened for differentially expressed ncRNAs (non-coding RNA) and mRNAs between hypoxia-inducible factor-1 (HIF-1α) knockdown GC cells and scrambled GC cells. Microarray data revealed that HIF-1α regulated the expression of LINC01355 (Hypoxia Yield Proliferation Associated LncRNA, HYPAL). HYPAL was found to be significantly upregulated in GC cells and tissues and was correlated with poor GC prognosis. Chromatin immunoprecipitation (ChIP) and luciferase reporter assays revealed that HIF-1α promoted HYPAL expression by binding the promoter region. A regulatory network for the competing endogenous RNA (ceRNA) was constructed using bioinformatics tools. Mechanistic studies revealed that HYPAL acted as a ceRNA of miR-431-5p to regulate CDK14 expression. Carcinogenic effects of HYPAL were evaluated in vitro and in vivo. The HIF-1α/HYPAL/miR-431-5p/CDK14 (Cyclin-dependent kinase 14) axis activated the Wnt/β-catenin signaling pathway and induced GC cell proliferation while inhibiting apoptosis. In conclusion, HYPAL is a potential molecular target for GC therapy.

Clinicopathological impacts of DNA methylation alterations on pancreatic ductal adenocarcinoma: prediction of early recurrence based on genome-wide DNA methylation profiling

PURPOSE

The present study was conducted to clarify the clinicopathological impacts of DNA methylation alterations on pancreatic ductal adenocarcinoma (PDAC).

METHODS

Genome-wide DNA methylation screening was performed using the Infinium HumanMethylation450 BeadChip, and DNA methylation quantification was verified using pyrosequencing. We analyzed fresh-frozen tissues from an initial cohort (17 samples of normal control pancreatic tissue [C] from 17 patients without PDAC, and 34 samples of non-cancerous pancreatic tissue [N] and 82 samples of cancerous tissue [T] both obtained from 82 PDAC patients) and formalin-fixed paraffin-embedded T samples from 34 patients in a validation cohort.

RESULTS

The DNA methylation profiles of N samples tended to differ from those of C samples, and 91,907 probes showed significant differences in DNA methylation levels between C and T samples. Epigenetic clustering of T samples was significantly correlated with a larger tumor diameter and early recurrence (ER), defined as relapse within 6 months after surgery. Three marker CpG sites, applicable to formalin-fixed paraffin-embedded surgically resected materials regardless of their tumor cell content, were identified for prediction of ER. The sensitivity and specificity for detection of patients belonging to the ER group using a panel combining these three marker CpG sites, including a CpG site in the CDK14 gene, were 81.8% and 71.7% and 88.9% and 70.4% in the initial and validation cohorts, respectively.

CONCLUSION

These findings indicate that DNA methylation alterations may have a clinicopathological impact on PDAC. Application of our criteria will ultimately allow prediction of ER after surgery to improve the outcome of PDAC patients.

The anti-tumor effect of miR-539-3p on colon cancer via regulating cell viability, motility, and nude mouse tumorigenicity with CDK14 inhibition

BACKGROUND

Colon cancer is one of the major causes of morbidity and mortality worldwide. MicroRNAs (miRNAs) play important functions in the growth and metastasis of colon cancer. This study aimed to investigate the anti-tumor effect of micro ribonucleic acid 539-3p (miR-539-3p) on colon cancer via regulation of cell viability, motility, and nude mouse tumorigenicity with cyclin-dependent kinase 14 (CDK14) inhibition.

METHODS

The target relationship between miR-539-3p and CDK14 was predicted using TargetScan software, and were detected by luciferase reporter assay. Cell counting kit-8 (CCK-8) assay and flow cytometry were employed to examine cell proliferation and apoptosis. Western blotting was employed to measure the protein expression levels of p27, cleaved caspase-3, and epithelial (E)- and neural (N)-cadherin. The effect of miR-539-3p on tumor growth was evaluated by establishing a xenograft tumor model in nude mice.

RESULTS

The target relationship of CDK14 and miR-539-3p was identified as a negative regulator. Overexpression of miR-539-3p significantly inhibited SW620 and SW480 cell proliferation, promoted cell apoptosis, and suppressed cell invasion by targeting CDK14. The xenograft tumor model showed that the overexpression of miR-539-3p reduced tumor weight and volume. Immunohistochemical staining revealed that the overexpression of miR-539-3p inhibited the expression of Ki67 and E-cadherin. Additionally, terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) staining showed that overexpression of miR-539-3p induced apoptosis.

CONCLUSIONS

Overexpression of miR-539-3p inhibited SW620 and SW480 cell proliferation, promoted cell apoptosis, and suppressed cell invasion by targeting CDK14. Therefore, miR-539-3p may be a useful diagnostic and therapeutic biomarker for colon cancer.

Targeting CDK12 for Cancer Therapy: Function, Mechanism, and Drug Discovery

Cyclin-dependent kinase 12 (CDK12) is a member of the CDK family of proteins (CDK) and is critical for cancer development. Years of study into CDK12 have generated much information regarding the intricacy of its function and mechanism as well as inhibitors against it for oncological research. However, there remains a lack of understanding regarding the role of CDK12 in carcinogenesis and cancer prevention. An exhaustive comprehension of CDK12 will highly stimulate the development of new strategies for treating and preventing cancer. Here, we review the literature of CDK12, with a focus on its function, its role in signaling, and how to use it as a target for discovery of novel drugs for cancer prevention and therapy.

LncRNA MIR4435-2HG triggers ovarian cancer progression by regulating miR-128-3p/CKD14 axis

Background

Accumulating studies showed that long noncoding RNAs (lncRNAs) played vital roles in cancer progression. LncRNA MIR4435-2HG was proved to act as an oncogene in various tumors. However, the underlying function of MIR4435-2HG in ovarian cancer (OC) remains unclear.

Methods

The expression levels of MIR4435-2HG, miR-128-3p and cyclin-dependent kinase 14 (CDK14) were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation and apoptosis in OC cells were detected by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and flow cytometric analysis, respectively. Transwell assay was applied to evaluate cell migration and invasion. Wound healing assay was performed to monitor the migration rate. Western blot assay was performed to detect the protein levels of Bcl-2, Cleaved PARP, E-cadherin, Vimentin and CDK14 in OC cells. The binding sites between miR-128-3p and MIR4435-2HG or CDK14 were predicted by online tool starBase and their relationship was confirmed by dual-luciferase reporter assay, RIP assay and pull-down experiment.

Results

MIR4435-2HG and CDK14 were over-expressed in OC tissues and cells. Patients with high MIR4435-2HG expression had poorer overall survival (OS) than patients with low MIR4435-2HG expression. MIR4435-2HG knockdown inhibited proliferation, invasion and migration but induced apoptosis of OC cells via miR-128-3p/CDK14 axis. In conclusion, MIR4435-2HG knockdown suppressed the progression of OC cells through downregulating CDK14 expression by the promotion of miR-128-3p.

The Roles of Cyclin-Dependent Kinases in Cell-Cycle Progression and Therapeutic Strategies in Human Breast Cancer

Cyclin-dependent kinases (CDKs) are serine/threonine kinases whose catalytic activities are regulated by interactions with cyclins and CDK inhibitors (CKIs). CDKs are key regulatory enzymes involved in cell proliferation through regulating cell-cycle checkpoints and transcriptional events in response to extracellular and intracellular signals. Not surprisingly, the dysregulation of CDKs is a hallmark of cancers, and inhibition of specific members is considered an attractive target in cancer therapy. In breast cancer (BC), dual CDK4/6 inhibitors, palbociclib, ribociclib, and abemaciclib, combined with other agents, were approved by the Food and Drug Administration (FDA) recently for the treatment of hormone receptor positive (HR+) advanced or metastatic breast cancer (A/MBC), as well as other sub-types of breast cancer. Furthermore, ongoing studies identified more selective CDK inhibitors as promising clinical targets. In this review, we focus on the roles of CDKs in driving cell-cycle progression, cell-cycle checkpoints, and transcriptional regulation, a highlight of dysregulated CDK activation in BC. We also discuss the most relevant CDK inhibitors currently in clinical BC trials, with special emphasis on CDK4/6 inhibitors used for the treatment of estrogen receptor-positive (ER+)/human epidermal growth factor 2-negative (HER2−) M/ABC patients, as well as more emerging precise therapeutic strategies, such as combination therapies and microRNA (miRNA) therapy.

Wnt/β-catenin signalling in ovarian cancer: Insights into its hyperactivation and function in tumorigenesis

Epithelial ovarian cancer (EOC) is the deadliest female malignancy. The Wnt/β-catenin pathway plays critical roles in regulating embryonic development and physiological processes. This pathway is tightly regulated to ensure its proper activity. In the absence of Wnt ligands, β-catenin is degraded by a destruction complex. When the pathway is stimulated by a Wnt ligand, β-catenin dissociates from the destruction complex and translocates into the nucleus where it interacts with TCF/LEF transcription factors to regulate target gene expression. Aberrant activation of this pathway, which leads to the hyperactivity of β-catenin, has been reported in ovarian cancer. Specifically, mutations of CTNNB1, AXIN, or APC, have been observed in the endometrioid and mucinous subtypes of EOC. In addition, upregulation of the ligands, abnormal activation of the receptors or intracellular mediators, disruption of the β-catenin destruction complex, inhibition of the association of β-catenin/E-cadherin on the cell membrane, and aberrant promotion of the β-catenin/TCF transcriptional activity, have all been reported in EOC, especially in the high grade serous subtype. Furthermore, several non-coding RNAs have been shown to regulate EOC development, in part, through the modulation of Wnt/β-catenin signalling. The Wnt/β-catenin pathway has been reported to promote cancer stem cell self-renewal, metastasis, and chemoresistance in all subtypes of EOC. Emerging evidence also suggests that the pathway induces ovarian tumor angiogenesis and immune evasion. Taken together, these studies demonstrate that the Wnt/β-catenin pathway plays critical roles in EOC development and is a strong candidate for the development of targeted therapies.

Cyclin dependent kinase (CDK) inhibitors as anticancer drugs: Recent advances (2015-2019)

Sustained proliferative capacity and gene dysregulation are hallmarks of cancer. In mammalian cells, cyclin-dependent kinases (CDKs) control critical cell cycle checkpoints and key transcriptional events in response to extracellular and intracellular signals leading to proliferation. Significant clinical activity for the treatment of hormone receptor positive metastatic breast cancer has been demonstrated by palbociclib, ribociclib and abemaciclib, dual CDK4/6 inhibitors recently FDA-approved. SY-1365, a CDK7 inhibitor has shown initial encouraging data in phase I for solid tumors treatment. These results have rejuvenated the CDKs research field. This review provides an overview of relevant advances on CDK inhibitor research since 2015 to 2019, with special emphasis on transcriptional CDK inhibitors, new emerging strategies such as target protein degradation and compounds under clinical evaluation.

The role of lncRNA MSC-AS1/miR-29b-3p axis-mediated CDK14 modulation in pancreatic cancer proliferation and Gemcitabine-induced apoptosis

Pancreatic ductal adenocarcinoma (PDAC) remains a leading cause of cancer-related death due to the failure of traditional therapies. In the present study, we attempted to construct a lncRNA-miRNA-mRNA network which may modulate PDAC cell proliferation and Gemcitabine-induced cell apoptosis starting from CDK14, a new member of the CDK family and an oncogene in many cancers. Based on TCGA data, a significant positive correlation was observed between lncRNA MSC-AS1 and CDK14. Moreover, MSC-AS1 expression was upregulated in PDAC tissues. Higher MSC-AS1 expression was correlated with poorer prognosis in patients with PDAC. MSC-AS1 knockdown in Panc-1 and BxPC-3 cells significantly inhibited the cell proliferation. Moreover, miR-29b-3p, which has been reported to act as a tumor suppressor, was predicted to bind to both MSC-AS1 and CDK14. Contrary to MSC-AS1, higher miR-29b-3p expression was correlated to better prognosis in patients with PDAC. In both PDAC cell lines, miR-29b-3p negatively regulated MSC-AS1 and CDK14. As confirmed using luciferase reporter gene and RIP assays, MSC-AS1 served as a ceRNA for miR-29b-3p to counteract miR-29b-mediated CDK14 repression. MSC-AS1 knockdown inhibited CDK14 protein levels and PDAC proliferation and enhanced gemcitabine-induced cell death and apoptosis while miR-29b-3p inhibition exerted an opposing effect; the effect of MSC-AS1 knockdown was partially attenuated by miR-29b-3p inhibition. Taken together, we demonstrated that MSC-AS1/miR-29b-3p axis modulates the cell proliferation and GEM-induced cell apoptosis in PDAC cell lines through CDK14. We provided a novel experimental basis for PDAC treatment from the perspective of lncRNA-miRNA-mRNA network.

MiR-542-3p, a microRNA targeting CDK14, suppresses cell proliferation, invasiveness, and tumorigenesis of epithelial ovarian cancer

MicroRNA-542-3p (miR-542-3p) has been implicated in several cancers; however, its precise role in ovarian cancer is unclear. In this study, we found that miR-542-3p was significantly downregulated in epithelial ovarian cancer (EOC) tissues and cell lines. Functional assays showed that overexpression of miR-542-3p suppressed tumor cell proliferation, migration, and invasion in vitro, whereas miR-542-3p knockdown dramatically promoted tumor cell proliferation and invasion. An in vivo assay also revealed that miR-542-3p overexpression significantly attenuated tumor growth. Mechanistically, the gene of cyclin-dependent kinase 14 (CDK14) was identified as a novel target of miR-542-3p. CDK14 overexpression reversed the suppressive effects of miR-542-3p in ovarian cancer cells. Collectively, these results suggest that miR-542-3p functions as a tumor-suppressive miRNA in ovarian cancer by directly targeting CDK14. Our data provide novel insights into potential future treatments for patients with ovarian cancer.

Knockdown of NEAT1 repressed the malignant progression of glioma through sponging miR-107 and inhibiting CDK14

Aberrant expressions of long noncoding RNAs (lncRNAs) contribute to carcinogenesis via regulating tumor suppressors or oncogenes. LncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) has been recognized as an oncogene to promote tumor progression of many cancers. However, the function of NEAT1 in glioma remains poorly discovered. Currently, we focused on the role of NEAT1 in glioma. Here, we found that NEAT1 was greatly upregulated in glioma cells compared with normal human astrocytes (NHAs). Meanwhile, miR-107 was significantly downregulated in glioma cell lines. Then, we observed that knockdown of NEAT1 suppressed the growth and invasion of glioma cells including U251 and SW1783 cells. Reversely, overexpression of NEAT1 dramatically induced glioma cell survival, increased cell colony formation, and promoted cell invasion ability. Subsequently, bioinformatics analysis was performed to predict the correlation between NEAT1 and miR-107. Moreover, it was revealed that NEAT1 could modulate miR-107 via serving as an endogenous sponge of miR-107. The direct binding correlation between NEAT1 and miR-107 was validated in our study. In addition, cyclin dependent kinase 14 (CDK14) was predicted as an messenger RNA target of miR-107 and the association between them was confirmed in our research. Moreover, we implied that NEAT1 demonstrated its biological functions via regulating miR-107 and CDK14 in vivo. In summary, our findings indicated that NEAT1/miR-107/CDK14 axis participated in glioma development. NEAT1 could act as a significant prognostic biomarker in glioma progression.

LncRNA H19/miR-194/PFTK1 axis modulates the cell proliferation and migration of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) remains a huge challenge due to its high mortality and morbidity; gene therapy might be a promising treatment for PDAC. The critical role of Wnt-signaling pathway in cancer pathogenesis has been widely recognized; cyclin-dependent kinase 14 (CDK14, PFTK1)-induced low-density lipoprotein receptor-related proteins 5/6 (LRP5/6) phosphorylation is an important issue in Wnt-signaling activation. Long noncoding RNA (LncRNA)-microRNA (miRNA)-messenger RNA (mRNA) modulating the pathogenesis of cancers has been regarded as a major mechanism. In the current study, upregulated lncRNAs positively correlated with PFTK1 were analyzed and selected using The Cancer Genome Atlas (TCGA) database. Of them, lncRNA H19 can activate Wnt signaling in cancers. In PDAC tissues, the expression of H19 and PFTK1 were upregulated; H19 knockdown suppressed the cell proliferation and migration of PDAC, while PFTK1 overexpression partially attenuated the suppressive effect of H19 knockdown. As analyzed by TCGA and predicted by online tools, miR-194 was negatively correlated with PFTK1 and might bind to both H19 and PFTK1, which was further confirmed by luciferase reporter and RNA immunoprecipitation assays. Moreover, the effect of H19 knockdown on PFTK1 protein and the cell proliferation and migration could be partially reversed by miR-194 inhibition; H19/miR-194 axis modulated PDAC cell proliferation and migration through PFTK1 downstream Wnt signaling. Results suggested that rescuing miR-194 expression in PDAC can inhibit lncRNA H19 and PFTK1 expression, subsequently suppressing PDAC cell proliferation and migration. Due to the complexity of the lncRNA-miRNA-mRNA network, further in vivo experiments examining potential side effects are needed in future study to explore the clinical application of these findings.

Increased expression of LINC01510 predicts poor prognosis and promotes malignant progression in human non-small cell lung cancer

Non-small cell lung cancer (NSCLC), the most prevalent type of lung cancer, is one of the most leading causes of cancer-related morbidity and mortality worldwide. Evidence is accumulating that long non-coding RNAs (lncRNAs) play vital regulatory roles in tumor development and progression. LINC01510, a novel tumor-related lncRNA, has been identified as an oncogene in colorectal cancer; however, its role in NSCLC remains poorly understood. This study aimed to characterize the biological role of LINC01510 in NSCLC and illuminate the molecular mechanisms. Here we found that LINC01510 was highly expressed in NSCLC tissues. Besides, Fisher's exact test showed that high expression of LINC01510 was associated with larger tumor size, advanced TNM stage and lymph node metastasis. Kaplan-Meier survival analysis showed that patients with high LINC01510 expression had a much lower overall survival rate. Gain- and loss-of-function approaches were employed to investigate the effects of LINC01510 on NSCLC cell phenotypes. Functional studies demonstrated that LINC01510 over-expression promoted NSCLC cell proliferation, cell cycle progression, migration and invasion, but shRNA-mediated LINC01510 depletion inhibited NSCLC cell proliferation, cell cycle progression, migration and invasion. Notably, LINC01510 ablation suppressed tumorigenicity of NSCLC cells in a murine xenograft model. Furthermore, mechanistic studies revealed that LINC01510 exerted its oncogenic functions in NSCLC through miR-339-5p-mediated regulation of CDK14. To sum up, our data indicate that increased expression of LINC01510 predicts poor prognosis and promotes tumorigenesis in NSCLC. Collectively, this study may provide a basis for LINC01510 as a candidate therapeutic target in NSCLC.

Long noncoding RNA LINC00858 promotes osteosarcoma through regulating miR-139-CDK14 axis

Long noncoding RNAs (lncRNAs) have been identified to modulate the tumorigenesis of human cancers. The in-depth of lncRNAs on human osteosarcoma oncogenesis is still ambiguous. In present study, functional and mechanism experiments were conducted to investigate the role of long intergenic non-protein coding RNA 00858 (LINC00858) on human osteosarcoma tumorigenesis. Results demonstrated that LINC00858 expression was significantly upregulated in both osteosarcoma tissues and cell lines. Mechanism assays presented that LINC00858 silencing significantly repressed osteosarcoma cells' proliferation and invasion in vitro, and inhibited the tumor growth in vivo. In further experiments, LINC00858 was identified to sponge miR-139 to form RNA-induced silencing complex (RISC) using luciferase reporter assay and RNA immunoprecipitation (RIP). Besides, CDK14 was validated to be the target protein the miR-139. Rescue experiments confirmed the role of LINC00858/miR-139/CDK14 pathway on osteosarcoma cells' phenotype. In summary, these data prove that LINC00858/miR-139/CDK14 axis promotes the tumorigenesis of osteosarcoma, providing a new mechanism or target for osteosarcoma.

MicroRNA-613 impedes the proliferation and invasion of glioma cells by targeting cyclin-dependent kinase 14

Increasing evidence has suggested that microRNAs (miRNAs) are critical regulators of tumorigenesis. MicroRNA-613 (miR-613) has recently been reported as a novel tumor-related miRNA that plays an important role in multiple cancers. However, the expression and functional significance of miR-613 in glioma remains unclear. In this study, we aimed to investigate the biological function of miR-613 in glioma. We found that miR-613 expression was frequently downregulated in glioma tissues and cell lines compared with normal controls. Overexpression of miR-613 impeded proliferation and colony formation and induced cell cycle arrest in G0/G1 phase, and also inhibited the invasive ability of glioma cells. By contrast, miR-613 inhibition had the opposite effects. Bioinformatic analysis and dual-luciferase reporter assays showed that miR-613 directly targets the 3'-untranslated region of cyclin-dependent kinase 14 (CDK14). Real-time quantitative PCR and Western blot analysis showed that CDK14 expression is negatively regulated by miR-613. In addition, miR-613 expression was inversely correlated with CDK14 expression in clinical glioma tissues. Moreover, overexpression of miR-613 decreased the protein expression of β-catenin and inhibited the activation of Wnt signaling. Importantly, the antitumor effects of miR-613 were significantly reversed by CDK14 overexpression. Overall, our results show that miR-613 inhibits glioma cell proliferation and invasion by downregulating CDK14, suggesting that miR-613 and CDK14 may serve as potential therapeutic targets for the treatment of glioma.

miR-216a inhibits osteosarcoma cell proliferation, invasion and metastasis by targeting CDK14

Osteosarcoma (OS) has emerged as the most common primary musculoskeletal malignant tumour affecting children and young adults. Cyclin-dependent kinases (CDKs) are closely associated with gene regulation in tumour biology. Accumulating evidence indicates that the aberrant function of CDK14 is involved in a broad spectrum of diseases and is associated with clinical outcomes. MicroRNAs (miRNAs) are crucial epigenetic regulators in the development of OS. However, the essential role of CDK14 and the molecular mechanisms by which miRNAs regulate CDK14 in the oncogenesis and progression of OS have not been fully elucidated. Here we found that CDK14 expression was closely associated with poor prognosis and overall survival of OS patients. Using dual-luciferase reporter assays, we also found that miR-216a inhibits CDK14 expression by binding to the 3′-untranslated region of CDK14. Overexpression of miR-216a significantly suppressed cell proliferation, migration and invasion in vivo and in vitro by inhibiting CDK14 production. Overexpression of CDK14 in the miR-216a-transfected OS cells effectively rescued the suppression of cell proliferation, migration and invasion caused by miR-216a. In addition, Kaplan–Meier analysis indicated that miR-216a expression predicted favourable clinical outcomes for OS patients. Moreover, miR-216a expression was downregulated in OS patients and was negatively associated with CDK14 expression. Overall, these data highlight the role of the miR-216a/CDK14 axis as a novel pleiotropic modulator and demonstrate the associated molecular mechanisms, thus suggesting the intriguing possibility that miR-216a activation and CDK14 inhibition may be novel and attractive therapeutic strategies for treating OS patients.