Cancer upregulated gene (CUG)2 elevates YAP1 expression, leading to enhancement of epithelial-mesenchymal transition in human lung cancer cells

Role of NEK2 in tumorigenesis and tumor progression

Never in mitosis A (NIMA)-related kinase 2 (NEK2) is a serine/threonine kinase found in the nucleus and cytoplasm throughout the cell cycle. NEK2 is overexpressed in many cancers and is a biomarker of poor prognosis. Factors contributing to NEK2 elevation in cancer cells include oncogenic transcription factors, decreased ubiquitination, DNA methylation, and the circular RNA (circRNA)/long noncoding RNA (lncRNA)-miRNA axis. NEK2 overexpression produces chromosomal instability and aneuploidy, thereby enhancing cancer progression and suppressing antitumor immunity, which highlights the prominence of NEK2 in tumorigenesis and tumor progression. Small-molecule inhibitors targeting NEK2 have demonstrated promising therapeutic potential in vitro and in vivo across various cancer types. This review outlines the regulatory mechanisms of NEK2 expression, emphasizes its functional roles in cancer initiation and progression, and highlights the anticancer properties of NEK2 inhibitors.

Integrated machine learning to predict the prognosis of lung adenocarcinoma patients based on SARS-COV-2 and lung adenocarcinoma crosstalk genes

Viruses are widely recognized to be intricately associated with both solid and hematological malignancies in humans. The primary goal of this research is to elucidate the interplay of genes between SARS-CoV-2 infection and lung adenocarcinoma (LUAD), with a preliminary investigation into their clinical significance and underlying molecular mechanisms. Transcriptome data for SARS-CoV-2 infection and LUAD were sourced from public databases. Differentially expressed genes (DEGs) associated with SARS-CoV-2 infection were identified and subsequently overlapped with TCGA-LUAD DEGs to discern the crosstalk genes (CGs). In addition, CGs pertaining to both diseases were further refined using LUAD TCGA and GEO datasets. Univariate Cox regression was conducted to identify genes associated with LUAD prognosis, and these genes were subsequently incorporated into the construction of a prognosis signature using 10 different machine learning algorithms. Additional investigations, including tumor mutation burden assessment, TME landscape, immunotherapy response assessment, as well as analysis of sensitivity to antitumor drugs, were also undertaken. We discovered the risk stratification based on the prognostic signature revealed that the low-risk group demonstrated superior clinical outcomes (p < 0.001). Gene set enrichment analysis results predominantly exhibited enrichment in pathways related to cell cycle. Our analyses also indicated that the low-risk group displayed elevated levels of infiltration by immunocytes (p < 0.001) and superior immunotherapy response (p < 0.001). In our study, we reveal a close association between CGs and the immune microenvironment of LUAD. This provides preliminary insight for further exploring the mechanism and interaction between the two diseases.

RHBDF1 modulates cisplatin sensitivity of small cell lung cancer through YAP1/Smad2 signaling pathway

Small cell lung cancer (SCLC) is a fatal tumor type that is prone to drug resistance. In our previous study, we showed that human rhomboid-5 homolog-1 (RHBDF1) was differentially expressed in 5 intrinsic cisplatin-resistant SCLC tissues compared with 5 intrinsic cisplatin-sensitive SCLC tissues by RNA sequencing, which intrigued us. We performed gain- and loss-of-function experiments to investigate RHBDF1 function, bioinformatics analysis, qRT-PCR, western blotting, and immunoprecipitation to elucidate the molecular mechanisms as well as detect RHBDF1 expression in SCLC by immunohistochemistry. We found that RHBDF1 knockdown promoted cell proliferation and cisplatin chemoresistance and inhibited apoptosis in vitro and in vivo. These effects could be reversed by overexpressing RHBDF1 in vitro. Mechanistically, RHBDF1 interacted with YAP1, which increased the phosphorylation of Smad2 and transported Smad2 to the nucleus. Among clinical specimens, the RHBDF1 was a low expression in SCLC and was associated with clinicopathological features and prognosis. We are the first to reveal that RHBDF1 inhibited cell proliferation and promoted cisplatin sensitivity in SCLC and elucidate a novel mechanism through RHBDF1/YAP1/Smad2 signaling pathway which played a crucial role in cisplatin chemosensitivity. Targeting this pathway can be a promising therapeutic strategy for chemotherapy resistance in SCLC.

BCAR4 facilitates trastuzumab resistance and EMT in breast cancer via sponging miR-665 and interacting with YAP1

Breast cancer antiestrogen resistance 4 (BCAR4) has been suggested that can modulate cell behavior, resulting in tumorigenesis and chemoresistance. However, the underlying mechanisms of BCAR4 in trastuzumab resistance (TR) is still elusive. Here, we explored the function and the underlying mechanism of BCAR4 involving in TR. We found that BCAR4 is significantly upregulated in trastuzumab-resistant BC cells. Knockdown of BCAR4 could sensitize the BC cells to trastuzumab and suppress epithelial-mesenchymal transition (EMT). Mechanically, BCAR4 promotes yes-associated protein 1 (YAP1) expression by competitively sponging miR-665, to activated TGF-β signaling. Reciprocally, YAP1 could occupy the BCAR4 promoter to enhance its transcription, suggesting that there exists a positive feedback regulation between YAP1 and BCAR4. Targeting the BCAR4/miR-665/YAP1 axis may provide a novel insight of therapeutic approaches for TR in BC.

Expressions and Clinical Significance of Met and YAP in Gastric Cancer Tissue Microarray

Objective

This study is aimed at investigating the expression of Met and YAP in gastric cancer and their impact on clinical prognosis.

Methods

Tissue samples and clinical data were collected from 89 patients with gastric cancer. Immunohistochemistry was performed to quantify the expression of Met and YAP using tissue microarray. The correlation between the expressions of Met, YAP, and clinicopathological characteristics of patients was determined using a chi-square test. Survival analysis was conducted using the Kaplan-Meier method, while multivariate survival analysis was performed using the Cox proportional hazard model. Bioinformatics analysis was carried out by downloading chip data from TCGA.

Results

The expression levels of both Met and YAP were significantly higher in gastric cancer tissues compared to adjacent tissues (P < 0.001). Met expression showed a positive association with P53 and CD133, whereas YAP expression correlated positively with tumor grade and CD133 (P < 0.05). Pearson's analysis revealed a significant correlation between Met expression and VEGFR as well as CD133, while YAP expression correlated with Ki67 and VEGFR (P < 0.05). Patients with high levels of both Met and YAP exhibited decreased survival time (P < 0.01). Furthermore, Met expression, N stage, and VEGFR were identified as independent risk factors for gastric cancer prognosis (P < 0.05), whereas no such association was observed for YAP expression. Bioinformatics analysis demonstrated a significant correlation between the expressions of Met and YAP; both proteins were highly expressed in gastric cancer patients accompanied by markedly reduced survival time.

Conclusion

The expressions of Met and YAP are closely associated with the survival outcomes as well as clinicopathological features in patients with gastric cancer. Moreover, our findings highlight that Met serves as an independent prognostic factor for gastric cancer.

Profiling and targeting cancer stem cell signaling pathways for cancer therapeutics

Tumorigenic cancer stem cells (CSCs) represent a subpopulation of cells within the tumor that express genetic and phenotypic profiles and signaling pathways distinct from the other tumor cells. CSCs have eluded many conventional anti-oncogenic treatments, resulting in metastases and relapses of cancers. Effectively targeting CSCs' unique self-renewal and differentiation properties would be a breakthrough in cancer therapy. A better characterization of the CSCs' unique signaling mechanisms will improve our understanding of the pathology and treatment of cancer. In this paper, we will discuss CSC origin, followed by an in-depth review of CSC-associated signaling pathways. Particular emphasis is given on CSC signaling pathways' ligand-receptor engagement, upstream and downstream mechanisms, and associated genes, and molecules. Signaling pathways associated with regulation of CSC development stand as potential targets of CSC therapy, which include Wnt, TGFβ (transforming growth factor-β)/SMAD, Notch, JAK-STAT (Janus kinase-signal transducers and activators of transcription), Hedgehog (Hh), and vascular endothelial growth factor (VEGF). Lastly, we will also discuss milestone discoveries in CSC-based therapies, including pre-clinical and clinical studies featuring novel CSC signaling pathway cancer therapeutics. This review aims at generating innovative views on CSCs toward a better understanding of cancer pathology and treatment.

Establishing a metastasis-related diagnosis and prognosis model for lung adenocarcinoma through CRISPR library and TCGA database

PURPOSE

Existing biomarkers for diagnosing and predicting metastasis of lung adenocarcinoma (LUAD) may not meet the demands of clinical practice. Risk prediction models with multiple markers may provide better prognostic factors for accurate diagnosis and prediction of metastatic LUAD.

METHODS

An animal model of LUAD metastasis was constructed using CRISPR technology, and genes related to LUAD metastasis were screened by mRNA sequencing of normal and metastatic tissues. The immune characteristics of different subtypes were analyzed, and differentially expressed genes were subjected to survival and Cox regression analyses to identify the specific genes involved in metastasis for constructing a prediction model. The biological function of RFLNA was verified by analyzing CCK-8, migration, invasion, and apoptosis in LUAD cell lines.

RESULTS

We identified 108 differentially expressed genes related to metastasis and classified LUAD samples into two subtypes according to gene expression. Subsequently, a prediction model composed of eight metastasis-related genes (RHOBTB2, KIAA1524, CENPW, DEPDC1, RFLNA, COL7A1, MMP12, and HOXB9) was constructed. The areas under the curves of the logistic regression and neural network were 0.946 and 0.856, respectively. The model effectively classified patients into low- and high-risk groups. The low-risk group had a better prognosis in both the training and test cohorts, indicating that the prediction model had good diagnostic and predictive power. Upregulation of RFLNA successfully promoted cell proliferation, migration, invasion, and attenuated apoptosis, suggesting that RFLNA plays a role in promoting LUAD development and metastasis.

CONCLUSION

The model has important diagnostic and prognostic value for metastatic LUAD and may be useful in clinical applications.

Inside the stemness engine: Mechanistic links between deregulated transcription factors and stemness in cancer

Cell identity is largely determined by its transcriptional profile. In tumour, deregulation of transcription factor expression and/or activity enables cancer cell to acquire a stem-like state characterised by capacity to self-renew, differentiate and form tumours in vivo. These stem-like cancer cells are highly metastatic and therapy resistant, thus warranting a more complete understanding of the molecular mechanisms downstream of the transcription factors that mediate the establishment of stemness state. Here, we review recent research findings that provide a mechanistic link between the commonly deregulated transcription factors and stemness in cancer. In particular, we describe the role of master transcription factors (SOX, OCT4, NANOG, KLF, BRACHYURY, SALL, HOX, FOX and RUNX), signalling-regulated transcription factors (SMAD, β-catenin, YAP, TAZ, AP-1, NOTCH, STAT, GLI, ETS and NF-κB) and unclassified transcription factors (c-MYC, HIF, EMT transcription factors and P53) across diverse tumour types, thereby yielding a comprehensive overview identifying shared downstream targets, highlighting unique mechanisms and discussing complexities.

Detection of YAP1 and AR-V7 mRNA for Prostate Cancer Prognosis Using an ISFET Lab-On-Chip Platform

Prostate cancer (PCa) is the second most common cause of male cancer-related death worldwide. The gold standard of treatment for advanced PCa is androgen deprivation therapy (ADT). However, eventual failure of ADT is common and leads to lethal metastatic castration-resistant PCa. As such, the detection of relevant biomarkers in the blood for drug resistance in metastatic castration-resistant PCa patients could lead to personalized treatment options. mRNA detection is often limited by the low specificity of qPCR assays which are restricted to specialized laboratories. Here, we present a novel reverse-transcription loop-mediated isothermal amplification assay and have demonstrated its capability for sensitive detection of AR-V7 and YAP1 RNA (3 × 10¹ RNA copies per reaction). This work presents a foundation for the detection of circulating mRNA in PCa on a non-invasive lab-on-chip device for use at the point-of-care. This technique was implemented onto a lab-on-chip platform integrating an array of chemical sensors (ion-sensitive field-effect transistors) for real-time detection of RNA. Detection of RNA presence was achieved through the translation of chemical signals into electrical readouts. Validation of this technique was conducted with rapid detection (<15 min) of extracted RNA from prostate cancer cell lines 22Rv1s and DU145s.

Investigating CENPW as a Novel Biomarker Correlated With the Development and Poor Prognosis of Breast Carcinoma

Breast invasive carcinoma (BRCA) is a carcinoma with a fairly high incidence, and the therapeutic schedules are generally surgery and chemotherapy. However, chemotherapeutic drugs tend to produce serious toxic side effects, which lead to the cessation of treatment. Therefore, it is imperative to develop treatment strategies that are more effective and have fewer side effects at the genetic level. Centromeric protein W (CENPW) is an oncogene that plays an important part in nucleosome assembly. To date, no studies have reported the prognostic significance of CENPW in breast carcinoma. In this study, we verified that CENPW expression is up-regulated in breast carcinoma and positively associated with the level of immune cell infiltration. The clinicopathological characteristics further suggest that CENPW expression is correlated with a worse prognosis of breast carcinoma. Interestingly, the CENPW mutation contributes to the poor prognosis. Next, we discovered that the genes interacting with CENPW are mainly concentrated in the cell cycle pathway, and CENPW is co-expressed with CDCA7, which is also highly expressed in breast carcinoma and leads to a worse prognosis. Our subsequent studies verified that knockdown of CENPW significantly inhibits the proliferation and migration of breast carcinoma cells and promotes their apoptosis rate. Notably, inhibition of CEMPW sensitizes breast cancer cells to chemotherapeutic drugs that have been found to induce cell cycle arrest. In summary, these results provide extensive data and experimental evidence that CENPW can serve as a novel predictor of breast cancer and may act as a prospective therapeutic target.

NEK2 promotes the migration and proliferation of ESCC via stabilization of YAP1 by phosphorylation at Thr-143

BACKGROUND

Esophageal Squamous Cell Carcinoma (ESCC) was characterized as a regional-prevalent and aggressive tumor with high morbidity and mortality. NIMA-related kinase 2 (NEK2) is an interesting oncogene, the alteration of which leads to patients-beneficial outcomes. We aimed to explore the role of NEK2 in ESCC and excavate its mechanism.

METHODS

RNA-seq data were downloaded from TCGA and GEO and analyzed by R software. The protein levels were detected by immunohistochemistry (IHC) or western blot (WB), and mRNA expression was detected by qRT-PCR. The in vitro role of proliferation and migration was detected by Transwell migration assay and by colony formation assay, respectively. The in vivo roles were explored using a subcutaneous xenograft tumor model, where immunofluorescence (IF) and IHC were employed to investigate expression and localization. The interaction between proteins was detected by immunoprecipitation. The stability of proteins was measured by WB in the presence of cycloheximide.

RESULTS

A higher level of NEK2 was found in ESCC than normal esophageal epithelia in GEO, TCGA, and tissue microarray, which was associated with worse prognoses. The NEK2 knockdown impaired the proliferation and migration of ESCC, which also downregulated YAP1 and EMT markers like N-cadherin and Vimentin in vitro. On the contrary, NEK2 overexpression enhanced the migration of ESCC and elevated the levels of YAP1, N-cadherin, and Vimentin. Additionally, the overexpression of YAP1 in NEK2 knocked down ESCCs partly rescued the corresponding decrease in migration. The knockdown of NEK2 played an anti-tumor role in vivo and was accompanied by a lower level and nucleus shuffling of YAP1. In mechanism, NEK2 interacted with YAP1 and increased the stability of both endogenous and exogenous YAP1 by preventing ubiquitination. Moreover, the computer-predicted phosphorylation site of YAP1, Thr-143, reduced the ubiquitination of HA-YAP1, strengthened its stability, and thus influenced the migration in vitro.

CONCLUSIONS

NEK2 is a prognostic oncogene highly expressed in ESCC and promotes the progression of ESCC in vitro and in vivo. Mechanistically, NEK2-mediated phosphorylation of YAP1 at Thr-143 protects it from proteasome degradation and might serve as a promising therapeutic target in ESCC. Video Abstract.

Translocalization of enhanced PKM2 protein into the nucleus induced by cancer upregulated gene 2 confers cancer stem cell-like phenotypes

Increased mRNA levels of cancer upregulated gene (CUG)2 have been detected in many different tumor tissues using Affymetrix microarray. Oncogenic capability of the CUG2 gene has been further reported. However, the mechanism by which CUG2 overexpression promotes cancer stem cell (CSC)-like phenotypes remains unknown. With recent studies showing that pyruvate kinase muscle 2 (PKM2) is overexpressed in clinical tissues from gastric, lung, and cervical cancer patients, we hypothesized that PKM2 might play an important role in CSC-like phenotypes caused by CUG2 overexpression. The present study revealed that PKM2 protein levels and translocation of PKM2 into the nucleus were enhanced in CUG2-overexpressing lung carcinoma A549 and immortalized bronchial BEAS-2B cells than in control cells. Ex-pression levels of c-Myc, CyclinD1, and PKM2 were increased in CUG2-overexpressing cells than in control cells. Furthermore, EGFR and ERK inhibitors as well as suppression of Yap1 and NEK2 expression reduced PKM2 protein levels. Interestingly, knockdown of β-catenin expression failed to reduce PKM2 protein levels. Furthermore, reduction of PKM2 expression with its siRNA hindered CSC-like phenotypes such as faster wound heal-ing, aggressive transwell migration, and increased size/number of sphere formation. The introduction of mutant S37A PKM2-green fluorescence protein (GFP) into cells without ability to move to the nucleus did not confer CSC-like phenotypes, whereas forced expression of wild-type PKM2 promoted such phenotypes. Overall, CUG2-induced increase in the expression of nuclear PKM2 contributes to CSC-like phenotypes by upregulating c-Myc and CyclinD1 as a co-activator.

Translocalization of enhanced PKM2 protein into the nucleus induced by cancer upregulated gene 2 confers cancer stem cell-like phenotypes

Increased mRNA levels of cancer upregulated gene (CUG)2 have been detected in many different tumor tissues using Affymetrix microarray. Oncogenic capability of the CUG2 gene has been further reported. However, the mechanism by which CUG2 overexpression promotes cancer stem cell (CSC)-like phenotypes remains unknown. With recent studies showing that pyruvate kinase muscle 2 (PKM2) is overexpressed in clinical tissues from gastric, lung, and cervical cancer patients, we hypothesized that PKM2 might play an important role in CSC-like phenotypes caused by CUG2 overexpression. The present study revealed that PKM2 protein levels and translocation of PKM2 into the nucleus were enhanced in CUG2-overexpressing lung carcinoma A549 and immortalized bronchial BEAS-2B cells than in control cells. Expression levels of c-Myc, CyclinD1, and PKM2 were increased in CUG2-overexpressing cells than in control cells. Furthermore, EGFR and ERK inhibitors as well as suppression of Yap1 and NEK2 expression reduced PKM2 protein levels. Interestingly, knockdown of β-catenin expression failed to reduce PKM2 protein levels. Furthermore, reduction of PKM2 expression with its siRNA hindered CSC-like phenotypes such as faster wound healing, aggressive transwell migration, and increased size/number of sphere formation. The introduction of mutant S37A PKM2-green fluorescence protein (GFP) into cells without ability to move to the nucleus did not confer CSC-like phenotypes, whereas forced expression of wild-type PKM2 promoted such phenotypes. Overall, CUG2-induced increase in the expression of nuclear PKM2 contributes to CSC-like phenotypes by upregulating c-Myc and CyclinD1 as a co-activator. [BMB Reports 2022;55(2): 98-103].

Elevated Expression of JMJD5 Protein Due to Decreased miR-3656 Levels Contributes to Cancer Stem Cell-like Phenotypes under Overexpression of Cancer Upregulated Gene 2

Overexpression of cancer upregulated gene (CUG) 2 induces cancer stem cell-like phenotypes, such as enhanced epithelial-mesenchymal transition, sphere formation, and doxorubicin resistance. However, the precise mechanism of CUG2-induced oncogenesis remains unknown. We evaluated the effects of overexpression of CUG2 on microRNA levels using a microRNA microarray. Levels of miR-3656 were decreased when CUG2 was overexpressed; on the basis of this result, we further examined the target proteins of this microRNA. We focused on Jumonji C domain-containing protein 5 (JMJD5), as it has not been previously reported to be targeted by miR-3656. When CUG2 was overexpressed, JMJD5 expression was upregulated compared to that in control cells. A 3′ untranslated region (UTR) assay revealed that an miR-3656 mimic targeted the JMJD5 3′UTR, but the miR-3656 mimic failed to target a mutant JMJD5 3′UTR, indicating that miR-3656 targets the JMJD5 transcript. Administration of the miR-3656 mimic decreased the protein levels of JMD5 according to Western blotting. Additionally, the miR-3656 mimic decreased CUG2-induced cell migration, evasion, and sphere formation and sensitized the cells to doxorubicin. Suppression of JMJD5, with its small interfering RNA, impeded CUG2-induced cancer stem cell-like phenotypes. Thus, overexpression of CUG2 decreases miR-3656 levels, leading to upregulation of JMJD5, eventually contributing to cancer stem cell-like phenotypes.

Molecular Mechanism of Antioxidant and Anti-Inflammatory Effects of Omega-3 Fatty Acids in Perilla Seed Oil and Rosmarinic Acid Rich Fraction Extracted from Perilla Seed Meal on TNF-α Induced A549 Lung Adenocarcinoma Cells

Industrially, after the removal of oil from perilla seeds (PS) by screw-type compression, the large quantities of residual perilla seed meal (PSM) becomes non-valuable waste. Therefore, to increase the health value and price of PS and PSM, we focused on the biological effects of perilla seed oil (PSO) and rosmarinic acid-rich fraction (RA-RF) extracted from PSM for their role in preventing oxidative stress and inflammation caused by TNF-α exposure in an A549 lung adenocarcinoma culture model. The A549 cells were pretreated with PSO or RA-RF and followed by TNF-α treatment. We found that PSO and RA-RF were not toxic to TNF-α-induced A549 cells. Both extracts significantly decreased the generation of reactive oxygen species (ROS) in this cell line. The mRNA expression levels of IL-1β, IL-6, IL-8, TNF-α, and COX-2 were significantly decreased by the treatment of PSO and RA-RF. The Western blot indicated that the expression of MnSOD, FOXO1, and NF-κB and phosphorylation of JNK were also significantly diminished by PSO and RA-RF treatment. The results demonstrated that PSO and RA-RF act as antioxidants to scavenge TNF-α induced ROS levels, resulting in decreased the expression of MnSOD, FOXO1, NF-κB and JNK signaling pathway in a human lung cell culture exposed to TNF-α.

ILK regulates osteogenic differentiation of Human Periodontal Ligament Stem Cells through YAP-mediated Mechanical Memory

Mechanical memory meant the mechanical properties of the matrix could influence the cell fate even after the matrix was changed and has been justified in many kinds of cells. To utilize the phenomenon to improve periodontal tissue engineering, we studied whether mechanical memory existed in human periodontal ligament stem cells and testified if ILK plays a role in this process. The substrate of different stiffness was fabricated by gelatin methacrylate hydrogel. Two groups of hPDLSCs with stiff (St) and soft (So) matrix respectively were cultivated. Then half of the cells exchanged their matrix stiffness in the fourth passage and therefore So, St, So-St and St-So were formed. Morphology of hPDLSCs and intracellular location of YAP was observed via fluorescence staining, osteogenic differentiation of hPDLSCs was assessed by Real-Time PCR, ALP staining and western blot. Then all these were reassessed after the ILK gene had been knocked down. The results showed that morphology and YAP location of hPDLSCs were different between matrix changed and unchanged groups; osteogenic genes expression, ALP staining and western blot also varied. After the ILK gene had been knocked down, the YAP location and osteogenic activity of hPDLSCs were significantly influenced. Thus, it could be concluded that mechanical memory exists in hPDLSCs; ILK is involved in this process.

Knockdown of CENPW Inhibits Hepatocellular Carcinoma Progression by Inactivating E2F Signaling

Aim:

This study aimed to evaluate the effects of centromere protein W (CENPW, also known as CUG2) in hepatocellular carcinoma (HCC).

Methods:

CENPW expression in HCC tissues and cells was detected by RT-qPCR assay. CCK-8 and colony formation assay were used to assess cell proliferation. Wound healing and Transwell assay was used to detect cell migration and invasion, respectively. The flow cytometry was used to analyze the cell cycle distribution and apoptosis.

Results:

CENPW expression was upregulated in HCC tissues and cells. Knockdown of CENPW inhibited cell proliferation, migration, and invasion and induced the G0/G1 phase arrest and cell apoptosis in HCC cells, which might involve the E2F signaling regulation.

Conclusion:

CENPW acted as an oncogenic role in HCC progression via activation E2F signaling. Our findings may provide new insights into the studying mechanisms of HCC.

Overexpressed WDR3 induces the activation of Hippo pathway by interacting with GATA4 in pancreatic cancer

BACKGROUND

WD repeat domain 3 (WDR3) is involved in a variety of cellular processes including gene regulation, cell cycle progression, signal transduction and apoptosis. However, the biological role of WDR3 in pancreatic cancer and the associated mechanism remains unclear. We seek to explore the immune-independent functions and relevant mechanism for WDR3 in pancreatic cancer.

METHODS

The GEPIA web tool was searched, and IHC assays were conducted to determine the mRNA and protein expression levels of WDR3 in pancreatic cancer patients. MTS, colony formation, and transwell assays were conducted to determine the biological role of WDR3 in human cancer. Western blot analysis, RT-qPCR, and immunohistochemistry were used to detect the expression of specific genes. An immunoprecipitation assay was used to explore protein-protein interactions.

RESULTS

Our study proved that overexpressed WDR3 was correlated with poor survival in pancreatic cancer and that WDR3 silencing significantly inhibited the proliferation, invasion, and tumor growth of pancreatic cancer. Furthermore, WDR3 activated the Hippo signaling pathway by inducing yes association protein 1 (YAP1) expression, and the combination of WDR3 silencing and administration of the YAP1 inhibitor TED-347 had a synergistic inhibitory effect on the progression of pancreatic cancer. Finally, the upregulation of YAP1 expression induced by WDR3 was dependent on an interaction with GATA binding protein 4 (GATA4), the transcription factor of YAP1, which interaction induced the nuclear translocation of GATA4 in pancreatic cancer cells.

CONCLUSIONS

We identified a novel mechanism by which WDR3 plays a critical role in promoting pancreatic cancer progression by activating the Hippo signaling pathway through the interaction with GATA4. Therefore, WDR3 is potentially a therapeutic target for pancreatic cancer treatment.

MERTK Inhibition: Potential as a Treatment Strategy in EGFR Tyrosine Kinase Inhibitor-Resistant Non-Small Cell Lung Cancer

Epidermal growth factor tyrosine kinase inhibitors (EGFR-TKIs) are currently the most effective treatment for non-small cell lung cancer (NSCLC) patients, who carry primary EGFR mutations. However, the patients eventually develop drug resistance to EGFR-TKIs after approximately one year. In addition to the acquisition of the EGFR T790M mutation, the activation of alternative receptor-mediated signaling pathways is a common mechanism for conferring the insensitivity of EGFR-TKI in NSCLC. Upregulation of the Mer receptor tyrosine kinase (MERTK), which is a member of the Tyro3-Axl-MERTK (TAM) family, is associated with a poor prognosis of many cancers. The binding of specific ligands, such as Gas6 and PROS1, to MERTK activates phosphoinositide 3-kinase (PI3K)/Akt and mitogen-activated protein kinase (MAPK) cascades, which are the signaling pathways shared by EGFR. Therefore, the inhibition of MERTK can be considered a new therapeutic strategy for overcoming the resistance of NSCLC to EGFR-targeted agents. Although several small molecules and monoclonal antibodies targeting the TAM family are being developed and have been described to enhance the chemosensitivity and converse the resistance of EGFR-TKI, few have specifically been developed as MERTK inhibitors. The further development and investigation of biomarkers which can accurately predict MERTK activity and the response to MERTK inhibitors and MERTK-specific drugs are vitally important for obtaining appropriate patient stratification and increased benefits in clinical applications.

Overexpression of Cancer Upregulated Gene 2 (CUG2) Decreases Spry2 Through c-Cbl, Leading to Activation of EGFR and β-Catenin Signaling

Purpose

The mechanism by which cancer upregulated gene 2 (CUG2) overexpression induces cancer stem cell-like phenotypes is not fully understood. Because the increased activity and expression of epidermal growth factor receptor (EGFR) kinase have been reported in A549 cancer cells overexpressing CUG2 (A549-CUG2) compared with control cells (A549-Vec), the Sprouty2 (Spry2) protein has gained attention as the downstream molecule of EGFR signaling. Therefore, we aim to identify the role of Spry2 in CUG2-overexpressing lung cancer cells.

Materials and Methods

Spry2 expression levels were examined in A549-CUG2 and A549-Vec cells by Western blotting and qRT-PCR. Cell migration, invasion, and sphere formation were examined after Spry2 suppression and overexpression. EGFR-Stat1 and Akt-ERK protein phosphorylation levels were detected via immunoblotting. NEK2 kinase and β-catenin reporter assay were performed for downstream of Spry2 signaling.

Results

Although A549-CUG2 cells showed lower levels of the Spry2 protein than A549-Vec cells, no difference in levels of Spry2 transcript was observed between both cells via qRT-PCR. Furthermore, MG132 treatment enhanced the protein levels and ubiquitination of Spry2, suggesting that Spry2 protein expression can be regulated via the ubiquitin-proteasome pathway. The enforced expression of c-Cbl, known as the binding partner of Spry2, decreased the Spry2 protein levels, whereas its knockdown oppositely increased them. Epithelial-mesenchymal transition (EMT) and sphere formation were increased in A549-Vec cells during Spry2 siRNA treatment, confirming the role of Spry2 in CUG2-induced oncogenesis. Furthermore, EMT and sphere formation were determined by the Spry2 protein levels through the regulation of EGFR-Stat1 and β-catenin-NEK2-Yap1 signaling pathways.

Conclusion

CUG2 reduces Spry2 protein levels, the negative signaling molecule of cell proliferation, via c-Cbl, possibly activating the EGFR and β-catenin signaling pathways and, in turn, contributing to the induction of cancer stem cell-like phenotypes.

Targeting Yes1 Associated Transcriptional Regulator Inhibits Hepatocellular Carcinoma Progression and Improves Sensitivity to Sorafenib: An in vitro and in vivo Study

Purpose

The aim of this study was to investigate the role of Yes1 associated transcriptional regulator (YAP1) in the pathology of hepatocellular carcinoma (HCC) and its potential as a therapeutic target.

Methods

YAP1 expression in HCC and adjacent tissues was determined via immunohistochemistry; in HCC and human normal liver cell lines, expression was examined via Western blotting. The effects of YAP1 knockdown and overexpression were detected following transfection of HCC cells with siRNA-YAP1 recombinants or pcDNA3.1-YAP1 plasmids. A tumor xenograft model was constructed by implanting YAP1-knockdown lentivirus-infected Hep-3B cells into nude mice, and the animals were treated with sorafenib.

Results

In patients with HCC, YAP1 was upregulated in tumor tissue compared with adjacent tissue, and its high expression in the tumor was associated with increased Edmonson grade. In vitro, YAP1 expression was increased in Hep-3B, SK-HEP-1 and Huh7 cells, while it was similar in SMMC-7721 cells and LO2 cells. Meanwhile, YAP1 increased cell proliferation and invasion, promoted the progression of epithelial-mesenchymal transition, and inhibited cell apoptosis in HCC cells; furthermore, YAP1 knockdown combined with the administration of sorafenib decreased cell viability and increased cell apoptosis compared with YAP1 knockdown or treatment with sorafenib alone. In vivo, YAP1 knockdown inhibited tumor growth and metastasis, whereas it promoted apoptosis; meanwhile, YAP1 knockdown synergized with sorafenib to suppress tumor progression in HCC mice.

Conclusion

YAP1 is upregulated in both HCC tumor tissues and cell lines. Moreover, it promotes cell proliferation and invasion and promoted the progression of epithelial-mesenchymal transition in vitro. Furthermore, targeting YAP1 inhibits HCC progression and improves sensitivity to sorafenib in vitro and in vivo.