Integrin α2β1 inhibits MST1 kinase phosphorylation and activates Yes-associated protein oncogenic signaling in hepatocellular carcinoma

Hepatocellular carcinoma: An analysis of the expression status of stress granules and their prognostic value

BACKGROUND

Hepatocellular carcinoma (HCC) is a global popular malignant tumor, which is difficult to cure, and the current treatment is limited.

AIM

To analyze the impacts of stress granule (SG) genes on overall survival (OS), survival time, and prognosis in HCC.

METHODS

The combined The Cancer Genome Atlas-Liver Hepatocellular Carcinoma (TCGA-LIHC), GSE25097, and GSE36376 datasets were utilized to obtain genetic and clinical information. Optimal hub gene numbers and corresponding coefficients were determined using the Least absolute shrinkage and selection operator model approach, and genes for constructing risk scores and corresponding correlation coefficients were calculated according to multivariate Cox regression, respectively. The prognostic model’s receiver operating characteristic (ROC) curve was produced and plotted utilizing the time ROC software package. Nomogram models were constructed to predict the outcomes at 1, 3, and 5-year OS prognostications with good prediction accuracy.

RESULTS

We identified seven SG genes (DDX1, DKC1, BICC1, HNRNPUL1, CNOT6, DYRK3, CCDC124) having a prognostic significance and developed a risk score model. The findings of Kaplan-Meier analysis indicated that the group with a high risk exhibited significantly reduced OS in comparison with those of the low-risk group (P < 0.001). The nomogram model’s findings indicate a significant enhancement in the accuracy of OS prediction for individuals with HCC in the TCGA-HCC cohort. Gene Ontology and Gene Set Enrichment Analysis suggested that these SGs might be involved in the cell cycle, RNA editing, and other biological processes.

CONCLUSION

Based on the impact of SG genes on HCC prognosis, in the future, it will be used as a biomarker as well as a unique therapeutic target for the identification and treatment of HCC.

Hepatocellular carcinoma: An analysis of the expression status of stress granules and their prognostic value

BACKGROUND

Hepatocellular carcinoma (HCC) is a global popular malignant tumor, which is difficult to cure, and the current treatment is limited.

AIM

To analyze the impacts of stress granule (SG) genes on overall survival (OS), survival time, and prognosis in HCC.

METHODS

The combined The Cancer Genome Atlas-Liver Hepatocellular Carcinoma (TCGA-LIHC), GSE25097, and GSE36376 datasets were utilized to obtain genetic and clinical information. Optimal hub gene numbers and corresponding coefficients were determined using the Least absolute shrinkage and selection operator model approach, and genes for constructing risk scores and corresponding correlation coefficients were calculated according to multivariate Cox regression, respectively. The prognostic model’s receiver operating characteristic (ROC) curve was produced and plotted utilizing the time ROC software package. Nomogram models were constructed to predict the outcomes at 1, 3, and 5-year OS prognostications with good prediction accuracy.

RESULTS

We identified seven SG genes (DDX1, DKC1, BICC1, HNRNPUL1, CNOT6, DYRK3, CCDC124) having a prognostic significance and developed a risk score model. The findings of Kaplan-Meier analysis indicated that the group with a high risk exhibited significantly reduced OS in comparison with those of the low-risk group (P < 0.001). The nomogram model’s findings indicate a significant enhancement in the accuracy of OS prediction for individuals with HCC in the TCGA-HCC cohort. Gene Ontology and Gene Set Enrichment Analysis suggested that these SGs might be involved in the cell cycle, RNA editing, and other biological processes.

CONCLUSION

Based on the impact of SG genes on HCC prognosis, in the future, it will be used as a biomarker as well as a unique therapeutic target for the identification and treatment of HCC.

Emerging Perspectives of YAP/TAZ in Human Skin Epidermal and Dermal Aging

Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) are key downstream effectors of the Hippo signaling pathway, which plays a central role in tissue homeostasis, organ development, and regeneration. While the dysregulation of YAP/TAZ has been linked to various human diseases, their involvement in the aging of human skin has only recently begun to manifest. In the skin, the YAP/TAZ effectors emerge as central regulators in maintaining homeostasis of epidermal stem cells and dermal extracellular matrix, and thus intimately linked to skin aging processes. This review underscores recent molecular breakthroughs highlighting how age-related decline of YAP/TAZ activity impacts human epidermal and dermal aging. Gaining insight into the evolving roles of YAP/TAZ in human skin aging presents a promising avenue for the development of innovative therapeutic approaches aimed at enhancing skin health and addressing age-related skin conditions.

Protective role of 17β-estradiol in alcohol-associated liver fibrosis is mediated by suppression of integrin signaling

BACKGROUND

Alcohol-associated liver disease is a complex disease regulated by genetic and environmental factors such as diet and sex. The combination of high-fat diet and alcohol consumption has synergistic effects on liver disease progression. Female sex hormones are known to protect females from liver disease induced by high-fat diet. In contrast, they promote alcohol-mediated liver injury. We aimed to define the role of female sex hormones on liver disease induced by a combination of high-fat diet and alcohol.

METHODS

Wild-type and protein arginine methyltransferase (Prmt)6 knockout female mice were subjected to gonadectomy (ovariectomy, OVX) or sham surgeries and then fed western diet and alcohol in the drinking water.

RESULTS

We found that female sex hormones protected mice from western diet/alcohol-induced weight gain, liver steatosis, injury, and fibrosis. Our data suggest that these changes are, in part, mediated by estrogen-mediated induction of arginine methyltransferase PRMT6. Liver proteome changes induced by OVX strongly correlated with changes induced by Prmt6 knockout. Using Prmt6 knockout mice, we confirmed that OVX-mediated weight gain, steatosis, and injury are PRMT6 dependent, while OVX-induced liver fibrosis is PRMT6 independent. Proteomic and gene expression analyses revealed that estrogen signaling suppressed the expression of several components of the integrin pathway, thus reducing integrin-mediated proinflammatory (Tnf, Il6) and profibrotic (Tgfb1, Col1a1) gene expression independent of PRMT6 levels. Integrin signaling inhibition using Arg-Gly-Asp peptides reduced proinflammatory and profibrotic gene expression in mice, suggesting that integrin suppression by estrogen is protective against fibrosis development.

CONCLUSIONS

Taken together, estrogen signaling protects mice from liver disease induced by a combination of alcohol and high-fat diet through upregulation of Prmt6 and suppression of integrin signaling.

The possible correlation between miR-762, Hippo signaling pathway, TWIST1, and SMAD3 in lung cancer and chronic inflammatory diseases

MicroRNAs are small RNA molecules that have a significant role in translational repression and gene silencing through binding to downstream target mRNAs. MiR-762 can stimulate the proliferation and metastasis of various types of cancer. Hippo pathway is one of the pathways that regulate tissue development and carcinogenesis. Dysregulation of this pathway plays a vital role in the progression of cancer. This study aimed to evaluate the possible correlation between miR-762, the Hippo signaling pathway, TWIST1, and SMAD3 in patients with lung cancer, as well as patients with chronic inflammatory diseases. The relative expression of miR-762, MST1, LATS2, YAP, TWIST1, and SMAD3 was determined in 50 lung cancer patients, 30 patients with chronic inflammatory diseases, and 20 healthy volunteers by real-time PCR. The levels of YAP protein and neuron-specific enolase were estimated by ELISA and electrochemiluminescence immunoassay, respectively. Compared to the control group, miR-762, YAP, TWIST1, and SMAD3 expression were significantly upregulated in lung cancer patients and chronic inflammatory patients, except SMAD3 was significantly downregulated in chronic inflammatory patients. MST1, LATS2, and YAP protein were significantly downregulated in all patients. MiR-762 has a significant negative correlation with MST1, LATS2, and YAP protein in lung cancer patients and with MST1 and LATS2 in chronic inflammatory patients. MiR-762 may be involved in the induction of malignant behaviors in lung cancer through suppression of the Hippo pathway. MiR-762, MST1, LATS2, YAP mRNA and protein, TWIST1, and SMAD3 may be effective diagnostic biomarkers in both lung cancer patients and chronic inflammatory patients. High YAP, TWIST1, SMA3 expression, and NSE level are associated with a favorable prognosis for lung cancer.

B4GALNT1 promotes hepatocellular carcinoma stemness and progression via integrin α2β1-mediated FAK and AKT activation

Background & Aims

β-1,4-N-Acetyl-galactosaminyltransferase 1 (B4GALNT1) has been reported to contribute to the development of human malignancies. However, its role in hepatocellular carcinoma (HCC) remains uncharacterised. In this study, we aimed to elucidate the role of B4GALNT1 in HCC stemness and progression.

Methods

Immunohistochemical staining was used to evaluate B4GALNT1 expression in HCC tissues and adjacent normal liver tissues. Flow cytometry analysis and sphere formation analysis were performed to investigate the role of B4GALNT1 in HCC stemness. Colony formation, Incucyte, wound-healing, Transwell migration, and invasion assays, and an animal model were used to study the role of B4GALNT1 in HCC progression. RNA-sequencing and co-immunoprecipitation were used to investigate the downstream targets of B4GALNT1.

Results

B4GALNT1 was upregulated in HCC and associated with poor clinical outcome of patients with the disease. Moreover, B4GALNT1 promoted HCC stemness, migration, invasion, and growth. Mechanistically, B4GALNT1 not only promoted the expression of the integrin α2β1 ligand THBS4, but also directly interacted with the β subunit of integrin α2β1 ITGB1 to inhibit its ubiquitin-independent proteasomal degradation, resulting in activation of FAK and AKT. Ophiopogonin D inhibited HCC stemness and progression by reducing ITGB1 and THBS4 expression and inhibiting FAK and AKT activation.

Conclusions

Our study suggests the B4GALNT1/integrin α2β1/FAK/PI3K/AKT axis as a therapeutic target for the inhibition of HCC stemness and tumour progression.

Impact and implications

The role and regulatory mechanism of B4GALNT1 in HCC have not been studied previously. Here, we reveal that B4GALNT1 has a crucial role in HCC stemness and progression by activating the integrin α2β1/FAK/PI3K/AKT axis, providing a potential target for HCC therapy. In addition, we find Ophiopogonin D as a potential therapeutic drug for patients with HCC.

Targeting integrin α2 as potential strategy for radiochemosensitization of glioblastoma

BACKGROUND

Glioblastoma (GBM) is a fast-growing primary brain tumor characterized by high invasiveness and resistance. This results in poor patient survival. Resistance is caused by many factors, including cell-extracellular matrix (ECM) interactions. Here, we addressed the role of adhesion protein integrin α2, which we identified in a high-throughput screen for novel potential targets in GBM cells treated with standard therapy consisting of temozolomide (TMZ) and radiation.

METHODS

In our study, we used a range of primary/stem-like and established GBM cell models in vitro and in vivo. To identify regulatory mechanisms, we employed high-throughput kinome profiling, Western blotting, immunofluorescence staining, reporter, and activity assays.

RESULTS

Our data showed that integrin α2 is overexpressed in GBM compared to normal brain and, that its deletion causes radiochemosensitization. Similarly, invasion and adhesion were significantly reduced in TMZ-irradiated GBM cell models. Furthermore, we found that integrin α2-knockdown impairs the proliferation of GBM cells without affecting DNA damage repair. At the mechanistic level, we found that integrin α2 affects the activity of activating transcription factor 1 (ATF1) and modulates the expression of extracellular signal-regulated kinase 1 (ERK1) regulated by extracellular signals. Finally, we demonstrated that integrin α2-deficiency inhibits tumor growth and thereby prolongs the survival of mice with orthotopically growing GBM xenografts.

CONCLUSIONS

Taken together our data suggest that integrin α2 may be a promising target to overcome GBM resistance to radio- and chemotherapy. Thus, it would be worth evaluating how efficient and safe the adjuvant use of integrin α2 inhibitors is to standard radio(chemo)therapy in GBM.

Integrins in human hepatocellular carcinoma tumorigenesis and therapy

ABSTRACT

Integrins are a family of transmembrane receptors that connect the extracellular matrix and actin skeleton, which mediate cell adhesion, migration, signal transduction, and gene transcription. As a bi-directional signaling molecule, integrins can modulate many aspects of tumorigenesis, including tumor growth, invasion, angiogenesis, metastasis, and therapeutic resistance. Therefore, integrins have a great potential as antitumor therapeutic targets. In this review, we summarize the recent reports of integrins in human hepatocellular carcinoma (HCC), focusing on the abnormal expression, activation, and signaling of integrins in cancer cells as well as their roles in other cells in the tumor microenvironment. We also discuss the regulation and functions of integrins in hepatitis B virus-related HCC. Finally, we update the clinical and preclinical studies of integrin-related drugs in the treatment of HCC.

Non-steroidal anti-inflammatory drugs and biomarkers: A new paradigm in colorectal cancer

Colorectal cancer is a sporadic, hereditary, or familial based disease in its origin, caused due to diverse set of mutations in large intestinal epithelial cells. Colorectal cancer (CRC) is a common and deadly disease that accounts for the 4^th worldwide highly variable malignancy. For the early detection of CRC, the most common predictive biomarker found endogenously are KRAS and ctDNA/cfDNA along with SEPT9 methylated DNA. Early detection and screening for CRC are necessary and multiple methods can be employed to screen and perform early diagnosis of CRC. Colonoscopy, an invasive method is most prevalent for diagnosing CRC or confirming the positive result as compared to other screening methods whereas several non-invasive techniques such as molecular analysis of breath, urine, blood, and stool can also be performed for early detection. Interestingly, widely used medicines known as non-steroidal anti-inflammatory drugs (NSAIDs) to reduce pain and inflammation have reported chemopreventive impact on gastrointestinal malignancies, especially CRC in several epidemiological and preclinical types of research. NSAID acts by inhibiting two cyclooxygenase enzymes, thereby preventing the synthesis of prostaglandins (PGs) and causing NSAID-induced apoptosis and growth inhibition in CRC cells. This review paper majorly focuses on the diversity of natural and synthetic biomarkers and various techniques for the early detection of CRC. An approach toward current advancement in CRC detection techniques and the role of NSAIDs in CRC chemoprevention has been explored systematically. Several prominent governing mechanisms of the anti-cancer effects of NSAIDs and their synergistic effect with statins for an effective chemopreventive measure have also been discussed in this review paper.

Arginine Methylation of Integrin Alpha-4 Prevents Fibrosis Development in Alcohol-Associated Liver Disease

BACKGROUND & AIMS

Alcohol-associated liver disease (ALD) comprises a spectrum of disorders including steatosis, steatohepatitis, fibrosis, and cirrhosis. We aimed to study the role of protein arginine methyltransferase 6 (PRMT6), a new regulator of liver function, in ALD progression.

METHODS

Prmt6-deficient mice and wild-type littermates were fed Western diet with alcohol in the drinking water for 16 weeks. Mice fed standard chow diet or Western diet alone were used as a control.

RESULTS

We found that PRMT6 expression in the liver is down-regulated in 2 models of ALD and negatively correlates with disease severity in mice and human liver specimens. Prmt6-deficient mice spontaneously developed liver fibrosis after 1 year and more advanced fibrosis after high-fat diet feeding or thioacetamide treatment. In the presence of alcohol Prmt6 deficiency resulted in a dramatic increase in fibrosis development but did not affect lipid accumulation or liver injury. In the liver PRMT6 is primarily expressed in macrophages and endothelial cells. Transient replacement of knockout macrophages with wild-type macrophages in Prmt6 knockout mice reduced profibrotic signaling and prevented fibrosis progression. We found that PRMT6 decreases profibrotic signaling in liver macrophages via methylation of integrin α-4 at R464 residue. Integrin α-4 is predominantly expressed in infiltrating monocyte derived macrophages. Blocking monocyte infiltration into the liver with CCR2 inhibitor reduced fibrosis development in knockout mice and abolished differences between genotypes.

CONCLUSIONS

Taken together, our data suggest that alcohol-mediated loss of Prmt6 contributes to alcohol-associated fibrosis development through reduced integrin methylation and increased profibrotic signaling in macrophages.

Advances in prognostic and therapeutic targets for hepatocellular carcinoma and intrahepatic cholangiocarcinoma: The hippo signaling pathway

Primary liver cancer is the sixth most frequently diagnosed cancer worldwide and the third leading cause of cancer-related death. The majority of the primary liver cancer cases are hepatocellular carcinoma and intrahepatic cholangiocarcinoma. Worldwide, there is an increasing incidence of primary liver cancer cases due to multiple risk factors ranging from parasites and viruses to metabolic diseases and lifestyles. Often, patients are diagnosed at advanced stages, depriving them of surgical curability benefits. Moreover, the efficacy of the available chemotherapeutics is limited in advanced stages. Furthermore, tumor metastases and recurrence make primary liver cancer management exceptionally challenging. Thus, exploring the molecular mechanisms for the development and progression of primary liver cancer is critical in improving diagnostic, treatment, prognostication, and surveillance modalities. These mechanisms facilitate the discovery of specific targets that are critical for novel and more efficient treatments. Consequently, the Hippo signaling pathway executing a pivotal role in organogenesis, hemostasis, and regeneration of tissues, regulates liver cells proliferation, and apoptosis. Cell polarity or adhesion molecules and cellular metabolic status are some of the biological activators of the pathway. Thus, understanding the mechanisms exhibited by the Hippo pathway is critical to the development of novel targeted therapies. This study reviews the advances in identifying therapeutic targets and prognostic markers of the Hippo pathway for primary liver cancer in the past six years.

Integrin α2 and β1 Cross-Communication with mTOR/AKT and the CDK-Cyclin Axis in Hepatocellular Carcinoma Cells

Simple Summary

Hepatocellular carcinoma (HCC) progression depends on two major processes, tumor growth and invasion. The present study investigated how these events are linked. A panel of HCC cell lines were stimulated with insulin-like growth factor-1 (IGF1) and the biological behavior was evaluated. IGF1 activated the proliferation and invasion cascade by altering the expression level of integrin α subtypes, which were associated with the AKT-mTOR pathway and the CDK-Cyclin axis. We assume that HCC progression is controlled by a fine-tuned network between IGF1 driven integrin signaling, the Akt-mTOR pathway, and the CDK-Cyclin axis. Concerted targeting of these pathways may, therefore, become an innovative option to prevent cancer dissemination.

Abstract

Integrin receptors contribute to hepatocellular carcinoma (HCC) invasion, while AKT-mTOR signaling controls mitosis. The present study was designed to explore the links between integrins and the AKT-mTOR pathway and the CDK-Cyclin axis. HCC cell lines (HepG2, Huh7, Hep3B) were stimulated with soluble collagen or Matrigel to activate integrins, or with insulin-like growth factor 1 (IGF1) to activate AKT-mTOR. HCC growth, proliferation, adhesion, and chemotaxis were evaluated. AKT/mTOR-related proteins, proteins of the CDK-Cyclin axis, focal adhesion kinase (FAK), and integrin-linked kinase (ILK) were determined following IGF1-stimulation or integrin knockdown. Stimulation with collagen or Matrigel increased tumor cell growth and proliferation. This was associated with significant alteration of the integrins α2, αV, and β1. Blockade of these integrins led to cell cycle arrest in G2/M and diminished the number of tumor cell clones. Knocking down the integrins α2 or β1 suppressed ILK, reduced FAK-phosphorylation and diminished AKT/mTOR, as well as the proteins of the CDK-Cyclin axis. Activating the cells with IGF1 enhanced the expression of the integrins α2, αV, β1, activated FAK, and increased tumor cell adhesion and chemotaxis. Blocking the AKT pathway canceled the enhancing effect of IGF on the integrins α2 and β1. These findings reveal that HCC growth, proliferation, and invasion are controlled by a fine-tuned network between α2/β1-FAK signaling, the AKT-mTOR pathway, and the CDK–Cyclin axis. Concerted blockade of the integrin α2/β1 complex along with AKT-mTOR signaling could, therefore, provide an option to prevent progressive dissemination of HCC.

High MST2 expression regulates lens epithelial cell apoptosis in age-related cataracts through YAP1 targeting GLUT1

Age-related cataract (ARC) is a severe visual impairment disease and its pathogenesis remains unclear. This study investigated the relevance of MST2/YAP1/GLUT1 in ARC development in vivo and in vitro, and explored the role and possible mechanisms of this pathway in oxidative damage-mediated apoptosis of lens epithelial cells (LECs). Western blot analysis and immunohistochemistry showed that MST2 and phosphorylated (p)-YAP (Ser127) protein levels were increased, and YAP1 and GLUT1 protein levels were decreased in LECs of ARC patients and aged mice. Additionally, differential expression of MST2 and YAP1 was associated with H₂O₂-induced apoptosis of human lens epithelial B3 (HLE-B3) cells. CCK-8 and Hoechst 33,342 apoptosis assays showed that MST2 and YAP1 were involved in H₂O₂-induced apoptosis of LECs. Subsequent experiments showed that, during MST2-mediated H₂O₂-induced apoptosis, p-YAP (Ser127) levels were elevated and immunofluorescence revealed nucleoplasmic translocation and inhibition of YAP1 protein expression. Furthermore, GLUT1 was in turn synergistically transcriptionally regulated by YAP1-TEAD1 in dual luciferase reporter assays. In conclusion, our study indicates that the MST2/YAP1/GLUT1 pathway plays a major role in the pathogenesis of ARC and LECs apoptosis, providing a new direction for future development of targeted inhibitors that block this signaling pathway to prevent, delay, or even cure ARC.

Pan-cancer analysis of non-coding transcripts reveals the prognostic onco-lncRNA HOXA10-AS in gliomas

Long non-coding RNAs (lncRNAs) are increasingly recognized as functional units in cancer and powerful biomarkers; however, most remain uncharacterized. Here, we analyze 5,592 prognostic lncRNAs in 9,446 cancers of 30 types using machine learning. We identify 166 lncRNAs whose expression correlates with survival and improves the accuracy of common clinical variables, molecular features, and cancer subtypes. Prognostic lncRNAs are often characterized by switch-like expression patterns. In low-grade gliomas, HOXA10-AS activation is a robust marker of poor prognosis that complements IDH1/2 mutations, as validated in another retrospective cohort, and correlates with developmental pathways in tumor transcriptomes. Loss- and gain-of-function studies in patient-derived glioma cells, organoids, and xenograft models identify HOXA10-AS as a potent onco-lncRNA that regulates cell proliferation, contact inhibition, invasion, Hippo signaling, and mitotic and neuro-developmental pathways. Our study underscores the pan-cancer potential of the non-coding transcriptome for identifying biomarkers and regulators of cancer progression.

The regulatory networks of the Hippo signaling pathway in cancer development

The Hippo signaling pathway is a relatively young tumor-related signaling pathway. Although it was discovered lately, research on it developed rapidly. The Hippo signaling pathway is closely relevant to the occurrence and development of tumors and the maintenance of organ size and other biological processes. This manuscript focuses on YAP, the core molecule of the Hippo signaling pathway, and discussion the upstream and downstream regulatory networks of the Hippo signaling pathway during tumorigenesis and development. It also summarizes the relevant drugs involved in this signaling pathway, which may be helpful to the development of targeted drugs for cancer therapy.

Transcatheter arterial chemoembolization combined with Hippo/YAP inhibition significantly improve the survival of rats with transplanted hepatocellular carcinoma

Background

This study aimed to explore the effect of inhibiting the Hippo/Yes-associated protein (YAP) signaling pathway on the outcomes of transcatheter arterial chemoembolization (TACE) in treating transplanted hepatocellular carcinoma (HCC).

Methods

A transplanted HCC rat model was established. Then, rats were randomly divided into four groups: Sham, TACE, verteporfin (inhibitor of Hippo/YAP), and TACE+verteporfin. Lent-OE-YAP was transfected into rats to overexpress YAP in vivo. After treatments, morphological changes, tumor weight, and the overall survival of rats in different groups were analyzed. Real-time PCR, immunohistochemistry staining, and Western blotting were used to determine the expression of factors related to the Hippo/YAP signaling pathway.

Results

Tumor weight and tissue lesions in the TACE and verteporfin groups were significantly reduced compared with the Sham group. Verteporfin significantly decreased tumor weight after TACE treatment. In addition, verteporfin significantly improved the overall survival of rats with transplanted HCC after TACE treatment. Compared with the Sham group, both TACE and verteporfin groups exhibited significantly decreased expression of macrophage-stimulating (MST)1, MST2, long-acting thyroid stimulator 1, transcriptional co-activator with PDZ-binding motif (TAZ), Yes-associated protein (YAP), TEA domain transcription factor (TEAD)1, TEAD2, TEAD3, and TEAD4. TACE plus verteporfin significantly enhanced the downregulation of effectors in the Hippo/YAP signaling pathway and decreased tumor size, while the overexpression of YAP exerted opposite effects.

Conclusion

The inhibition of the Hippo/YAP signaling pathway via verteporfin significantly improved the outcomes of TACE in treating transplanted HCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-021-01486-w.

Elevated MST1 leads to apoptosis via depletion of YAP1 in cardiomyocytes exposed to high glucose

BACKGROUND

Gestational diabetes mellitus is a risk factor for congenital heart defects. The article aimed to investigate the expression and roles of MST1, YAP1, Last1/2 and Survivin in modulating HG-induced cardiomyocyte apoptosis and maternal diabetes-induced heart abnormality.

METHODS

Diabetes mellitus was induced in rats using streptozotocin. The protein expression and phosphorylation analysis in fetal heart tissue was assessed by western blot and immunohistochemical staining. Hoechst 33342 staining assay was performed to explore H9C2 apoptosis. The gene and protein expression in H9C2 cells was assessed by quantitative PCR and western blot. Knockdown of gene expression was assessed by RNA interference.

RESULTS

Our results revealed that increased MST1 protein levels in the heart tissues of the offspring of diabetic rats in vivo and in H9C2 cardiomyocytes under HG treatment in vitro, respectively. Knockdown and overexpression experiments showed that MST1 played a key role in mediating HG-induced apoptosis in cardiomyocytes. Downregulation of YAP1 was associated with HG-induced, MST1-mediated cardiomyocyte apoptosis. Further study showed that MST1 downregulated the protein level of YAP1 through mediation of YAP1 phosphorylation on Ser127 and Ser397; this process also required LATS1/2 participation. MST1 overexpression increased the phosphorylation levels of LATS1/2, which were also shown to be increased in the heart tissues of diabetic offspring. We also found that YAP1 mediated the expression of Survivin during HG-induced apoptosis, and the Survivin-inhibitor YM155 partially inhibited the role of YAP1 in suppressing apoptosis induced by HG in cardiomyocytes.

CONCLUSION

These findings reveal a regulatory mechanism of MST1/YAP1/Survivin signaling in modulating cardiomyocyte apoptosis in vitro and maternal diabetes-induced congenital heart defects in vivo.

Control of skeletal morphogenesis by the Hippo-YAP/TAZ pathway

The Hippo-YAP/TAZ pathway is an important regulator of tissue growth, but can also control cell fate or tissue morphogenesis. Here, we investigate the function of the Hippo pathway during the development of cartilage, which forms the majority of the skeleton. Previously, YAP was proposed to inhibit skeletal size by repressing chondrocyte proliferation and differentiation. We find that, in vitro, Yap/Taz double knockout impairs murine chondrocyte proliferation, whereas constitutively nuclear nls-YAP5SA accelerates proliferation, in line with the canonical role of this pathway in most tissues. However, in vivo, cartilage-specific knockout of Yap/Taz does not prevent chondrocyte proliferation, differentiation or skeletal growth, but rather results in various skeletal deformities including cleft palate. Cartilage-specific expression of nls-YAP5SA or knockout of Lats1/2 do not increase cartilage growth, but instead lead to catastrophic malformations resembling chondrodysplasia or achondrogenesis. Physiological YAP target genes in cartilage include Ctgf, Cyr61 and several matrix remodelling enzymes. Thus, YAP/TAZ activity controls chondrocyte proliferation in vitro, possibly reflecting a regenerative response, but is dispensable for chondrocyte proliferation in vivo, and instead functions to control cartilage morphogenesis via regulation of the extracellular matrix.

Role of miR-30a-3p Regulation of Oncogenic Targets in Pancreatic Ductal Adenocarcinoma Pathogenesis

Our recent studies have implicated some passenger strands of miRNAs in the molecular pathogenesis of human cancers. Analysis of the microRNA (miRNA) expression signature in pancreatic ductal adenocarcinoma (PDAC) has shown that levels of miR-30a-3p, the passenger strand derived from pre-mir-30a, are significantly downregulated in PDAC tissues. This study aimed to identify the oncogenes closely involved in PDAC molecular pathogenesis under the regulation of miR-30a-3p. Ectopic expression assays showed that miR-30a-3p expression inhibited the aggressiveness of the PDAC cells, suggesting that miR-30a-3p acts as a tumor-suppressive miRNA in PDAC cells. We further identified 102 putative targets of miR-30a-3p regulation in PDAC cells by combining in silico analysis with gene expression data. Of these, ten genes (EPS8, HMGA2, ENDOD1, SLC39A10, TGM2, MGLL, SERPINE1, ITGA2, DTL, and UACA) were independent prognostic factors in multivariate analysis of survival of patients with PDAC (p < 0.01). We also investigated the oncogenic function of the integrin ITGA2 in PDAC cell lines. The integrin family comprises cell adhesion molecules expressed as heterodimeric, transmembrane proteins on the surface of various cells. Overexpression of ITGA2/ITGB1 (an ITGA2 binding partner) was detected in the PDAC clinical specimens. The knockdown of ITGA2 expression attenuated the malignant phenotypes of the PDAC cells. Together, results from these microRNA-based approaches can accelerate our understanding of PDAC molecular pathogenesis.

OGT knockdown counteracts high phosphate-induced vascular calcification in chronic kidney disease through autophagy activation by downregulating YAP

AIMS

Pathological vascular calcification (VC), a major risk factor for cardiovascular mortality, is a highly prevalent finding in patients with chronic kidney disease (CKD). We previously analyzed several pathways protecting against high phosphate-induced VC through induction of autophagy. Here, we explored how O-GlcNAc transferase (OGT) affected high phosphate-induced VC of CKD though mediation of autophagy.

MAIN METHODS

In the rats with CKD induced by 5/6 nephrectomy, the VC process was accelerated by a high phosphate diet. The calcification of vascular smooth muscle cells (VSMCs) was induced by high phosphate treatment. We then experimentally tested the effect of OGT on high phosphate-induced VC by conducting loss-of-function experiments. Co-immunoprecipitation and GST pull-down assays were performed to evaluate interaction between OGT and Yes-associated protein (YAP). In mechanistic studies of this pathway, we measured autophagy protein expression and autophagosome formation, as well as calcium deposition and calcium content in VSMCs and in vivo in response to altered expression of OGT and/or YAP.

KEY FINDINGS

OGT was up-regulated in high phosphate-induced VC models in vitro and in vivo. High phosphate-induced calcification in the rat aorta and VSMCs were suppressed by OGT silencing. OGT promoted the glycosylation of YAP to enhance its stability. Importantly, over-expressing YAP reduced autophagy and OGT expedited high phosphate-induced VC by inhibiting autophagy through upregulation of YAP.

SIGNIFICANCE

OGT silencing downregulated YAP to induce autophagy activation, thus suppressing high phosphate-induced VC, which highlighted a promising preventive target against high phosphate-induced VC in CKD.

Functional nanoarrays for investigating stem cell fate and function

Stem cells show excellent potential in the field of tissue engineering and regenerative medicine based on their excellent capability to not only self-renew but also differentiate into a specialized cell type of interest. However, the lack of a non-destructive monitoring system makes it challenging to identify and characterize differentiated cells before their transplantation without compromising cell viability. Thus, the development of a non-destructive monitoring method for analyzing cell function is highly desired and can significantly benefit stem cell-based therapies. Recently, nanomaterial-based scaffolds (e.g., nanoarrays) have made possible considerable advances in controlling the differentiation of stem cells and characterization of the differentiation status sensitively in real time. This review provides a selective overview of the recent progress in the synthesis methods of nanoarrays and their applications in controlling stem cell fate and monitoring live cell functions electrochemically. We believe that the topics discussed in this review can provide brief and concise guidelines for the development of novel nanoarrays and promote the interest in live cell study applications. A method which can not only control but also monitor stem cell fate and function will be a promising technology that can accelerate stem cell therapies.

Overexpressed ITGA2 contributes to paclitaxel resistance by ovarian cancer cells through the activation of the AKT/FoxO1 pathway

Ovarian cancer is one of the most malignant tumors of the female reproductive system, with high invasiveness. The disease is a severe threat to women's health. The ITGA2 gene, which codes for integrin subunit α2, is involved in the proliferation, invasion, and metastasis of cancer cells. Although previous studies have shown that ITGA2 increases in ovarian cancer, the specific molecular mechanism of how ITGA2 promotes ovarian cancer proliferation and metastasis is still unclear. In this study, we confirmed that ITGA2 was elevated in ovarian cancer, which led to poor prognosis and survival. Overexpressed ITGA2 promoted the proliferation of ovarian cancer cells. We also found that ITGA2 regulated the phosphorylation of forkhead box O1 (FoxO1) by mediating AKT phosphorylation, which provided a reasonable explanation for ITGA2's role in ovarian cancer's resistance to albumin paclitaxel. In summary, ITGA2 could be used as a new therapeutic target and prognostic indicator in ovarian cancer.

A combat with the YAP/TAZ-TEAD oncoproteins for cancer therapy

The transcriptional co-regulators YAP and TAZ pair primarily with the TEAD family of transcription factors to elicit a gene expression signature that plays a prominent role in cancer development, progression and metastasis. YAP and TAZ endow cells with various oncogenic traits such that they sustain proliferation, inhibit apoptosis, maintain stemness, respond to mechanical stimuli, engineer metabolism, promote angiogenesis, suppress immune response and develop resistance to therapies. Therefore, inhibiting YAP/TAZ- TEAD is an attractive and viable option for novel cancer therapy. It is exciting to know that many drugs already in the clinic restrict YAP/TAZ activities and several novel YAP/TAZ inhibitors are currently under development. We have classified YAP/TAZ-inhibiting drugs into three groups. Group I drugs act on the upstream regulators that are stimulators of YAP/TAZ activities. Many of the Group I drugs have the potential to be repurposed as YAP/TAZ indirect inhibitors to treat various solid cancers. Group II modalities act directly on YAP/TAZ or TEADs and disrupt their interaction; targeting TEADs has emerged as a novel option to inhibit YAP/TAZ, as TEADs are major mediators of their oncogenic programs. TEADs can also be leveraged on using small molecules to activate YAP/TAZ-dependent gene expression for use in regenerative medicine. Group III drugs focus on targeting one of the oncogenic downstream YAP/TAZ transcriptional target genes. With the right strategy and impetus, it is not far-fetched to expect a repurposed group I drug or a novel group II drug to combat YAP and TAZ in cancers in the near future.

Identification of Platform-Independent Diagnostic Biomarker Panel for Hepatocellular Carcinoma Using Large-Scale Transcriptomics Data

The high mortality rate of hepatocellular carcinoma (HCC) is primarily due to its late diagnosis. In the past, numerous attempts have been made to design genetic biomarkers for the identification of HCC; unfortunately, most of the studies are based on small datasets obtained from a specific platform or lack reasonable validation performance on the external datasets. In order to identify a universal expression-based diagnostic biomarker panel for HCC that can be applicable across multiple platforms, we have employed large-scale transcriptomic profiling datasets containing a total of 2,316 HCC and 1,665 non-tumorous tissue samples. These samples were obtained from 30 studies generated by mainly four types of profiling techniques (Affymetrix, Illumina, Agilent, and High-throughput sequencing), which are implemented in a wide range of platforms. Firstly, we scrutinized overlapping 26 genes that are differentially expressed in numerous datasets. Subsequently, we identified a panel of three genes (FCN3, CLEC1B, and PRC1) as HCC biomarker using different feature selection techniques. Three-genes-based HCC biomarker identified HCC samples in training/validation datasets with an accuracy between 93 and 98%, Area Under Receiver Operating Characteristic curve (AUROC) in a range of 0.97 to 1.0. A reasonable performance, i.e., AUROC 0.91–0.96 achieved on validation dataset containing peripheral blood mononuclear cells, concurred their non-invasive utility. Furthermore, the prognostic potential of these genes was evaluated on TCGA-LIHC and GSE14520 cohorts using univariate survival analysis. This analysis revealed that these genes are prognostic indicators for various types of the survivals of HCC patients (e.g., Overall Survival, Progression-Free Survival, Disease-Free Survival). These genes significantly stratified high-risk and low-risk HCC patients (p-value <0.05). In conclusion, we identified a universal platform-independent three-genes-based biomarker that can predict HCC patients with high precision and also possess significant prognostic potential. Eventually, we developed a web server HCCpred based on the above study to facilitate scientific community (http://webs.iiitd.edu.in/raghava/hccpred/).

TAZ target gene ITGAV regulates invasion and feeds back positively on YAP and TAZ in liver cancer cells

The Hippo pathway effectors yes-associated protein (YAP) and WW domain containing transcription regulator 1 (TAZ/WWTR1) support tumor initiation and progression in various cancer entities including hepatocellular carcinoma (HCC). However, to which extent YAP and TAZ contribute to liver tumorigenesis via common and exclusive molecular mechanisms is poorly understood. RNAinterference (RNAi) experiments illustrate that YAP and TAZ individually support HCC cell viability and migration, while for invasion additive effects were observed. Comprehensive expression profiling revealed partly overlapping YAP/TAZ target genes as well as exclusively regulated genes. Integrin-αV (ITGAV) is a novel TAZ-specific target gene, whose overexpression in human HCC patients correlates with poor clinical outcome, TAZ expression in HCCs, and the abundance of YAP/TAZ target genes. Functionally, ITGAV contributes to actin stress fiber assembly, tumor cell migration and invasion. Perturbation of ITGAV diminishes actin fiber formation and nuclear YAP/TAZ protein levels. We describe a novel Hippo downstream mechanism in HCC cells, which is regulated by TAZ and ITGAV and that feedbacks on YAP/TAZ activity. This mechanism may represent a therapeutic target structure since it contributes to signal amplification of oncogenic YAP/TAZ in hepatocarcinogenesis.

Large-scale analyses identify a cluster of novel long noncoding RNAs as potential competitive endogenous RNAs in progression of hepatocellular carcinoma

The abnormal expression of noncoding RNAs has attracted increasing interest in the field of hepatocellular carcinoma progression. However, the underlying molecular mechanisms mediated by noncoding RNAs in these processes are unclear. Here, we obtained the expression profiles of long noncoding RNAs, microRNAs, and mRNAs from the Gene Expression Omnibus database and identified hepatocarcinogenesis-specific differentially expressed transcripts. Next, we identified significant Gene Ontology and pathway terms that the differentially expressed transcripts involved in. Using functional analysis and target prediction, we constructed a hepatocellular carcinoma-associated deregulated competitive endogenous RNA network to reveal the potential mechanisms underlying tumor progression. By analyzing The Cancer Genome Atlas dataset, six key long noncoding RNAs showed significant association with overall survival as well as strong correlation with some microRNAs and mRNAs in the competitive endogenous RNA network. We further validated the above results and determined their diagnostic and prognostic value in clinical samples. Importantly, by large-scale analyses, we identified a cluster of long noncoding RNAs, GBAP1, MCM3AP-AS1, SLC16A1-AS1, C3P1, DIO3OS, and HNF4A-AS1 as candidate biomarkers for the diagnosis and prognosis of hepatocellular carcinoma, which will improve our understanding of competitive endogenous RNA-mediated regulatory mechanisms underlying hepatocellular carcinoma development and will provide novel therapeutic targets in the future.

Identification of cell context-dependent YAP-associated proteins reveals β1 and β4 integrin mediate YAP translocation independently of cell spreading

Yes-associated protein (YAP) is a transcriptional regulator and mechanotransducer, relaying extracellular matrix (ECM) stiffness into proliferative gene expression in 2D culture. Previous studies show that YAP activation is dependent on F-actin stress fiber mediated nuclear pore opening, however the protein mediators of YAP translocation remain unclear. Here, we show that YAP co-localizes with F-actin during activating conditions, such as sparse plating and culturing on stiff 2D substrates. To identify proteins mediating YAP translocation, we performed co-immunoprecipitation followed by mass spectrometry (co-IP/MS) for proteins that differentially associated with YAP under activating conditions. Interestingly, YAP preferentially associates with β1 integrin under activating conditions, and β4 integrin under inactivating conditions. In activating conditions, CRISPR/Cas9 knockout (KO) of β1 integrin (ΔITGB1) resulted in decreased cell area, which correlated with decreased YAP nuclear localization. ΔITGB1 did not significantly affect the slope of the correlation between YAP nuclear localization with area, but did decrease overall nuclear YAP independently of cell spreading. In contrast, β4 integrin KO (ΔITGB4) cells showed no change in cell area and similarly decreased nuclear YAP. These results reveal proteins that differentially associate with YAP during activation, which may aid in regulating YAP nuclear translocation.

Data mining of the expression and regulatory role of BCAT1 in hepatocellular carcinoma

Branched chain amino acid transaminase 1 (BCAT1) catalyzes the production of glutamates and branched-chain α-ketoacids from branched chain amino acids, and a normal BCAT1 expression is associated with tumorigenesis. Sequencing data from public databases, including The Cancer Genome Atlas, was used to analyze BCAT1 expression and regulation networks for hepatocellular carcinoma (HCC). Expression and methylation were assessed using UALCAN analysis, and data from multiple datasets concerning the BCAT1 expression level and associated survival rates were further analyzed using HCCDB; interaction networks of biological function were constructed using GeneMANIA. LinkedOmics was used to indicate correlations between BCAT1 and any identified differentially expressed genes. Gene enrichment analysis of BCAT-associated genes was conducted using the Web-based Gene SeT AnaLysis Toolkit. The expression levels of BCAT1 were increased in patients with HCC and in most cases, the level of BCAT1 promoter methylation was reduced. Interaction network analysis suggested that BCAT1 was involved in ‘metabolism’, ‘carcinogenesis’ and the ‘immune response’ via numerous cancer-associated pathways. The present study revealed the expression patterns and potential function networks of BCAT1 in HCC, providing insights for future research into the role of BCAT1 in hepatocarcinogenesis. In addition, the study provided researchers with a way to analyze the genes of interest so they can continue their research in the right direction.

Alpha6-Integrin Regulates FGFR1 Expression through the ZEB1/YAP1 Transcription Complex in Glioblastoma Stem Cells Resulting in Enhanced Proliferation and Stemness

Glioblastoma (GBM) is the most lethal primary brain tumor in adults and is known to be particularly aggressive and resistant to anti-cancer therapies, mainly due to the presence of GBM stem cells (GBMSC). By in vitro approaches supported by analysis from patients' databases, we determined how α6-integrin and Fibroblast Growth Factor Receptor 1 (FGFR1) work in concert to regulate proliferation and stemness of GBMSC. We showed that α6-integrin regulates the expression of FGFR1 and its target gene Fokhead Box M1 (FOXM1) via the ZEB1/YAP1 transcription complex. These results were in accordance with the positive correlation observed in GBM between α6-integrin expression and its target genes ZEB1/YAP1, FGFR1, and FOXM1 in the databases, TCGA and Rembrandt. In addition, the clinical data demonstrate that GBM patients with high levels of the five genes signature, including α6-integrin, ZEB1/YAP1, FGFR1 and FOXM1, have a significantly shorter overall survival. In vitro, we observed a similar decrease in the expression of stemness-related factors, neurospheres forming capacity, as well as spheroids growth when α6-integrin or FGFR1 was blocked individually with specific siRNA, whereas the combination of both siRNA led to a significantly higher inhibition of spheres formation. These data suggest that co-administration of anti-FGFR1 and anti-α6-integrin could provide an improved therapeutic response in GBMSC.

ADAR1 p110 Enhances Adhesion of Tumor Cells to Extracellular Matrix in Hepatocellular Carcinoma via Up-Regulating ITGA2 Expression

BACKGROUND Intrahepatic and distant metastases could be the major cause of treatment failure in hepatocellular carcinoma (HCC). The deep mechanism of HCC metastasis is closely related to the interaction between integrins and extracellular matrix (ECM) in tumor microenvironment. MATERIAL AND METHODS In vitro cell adhesion assay was performed to determine the capability of adhering to ECM elements of HCC cells. To modulate the expression status of ADAR1 p110 in tumor cells, lentivirus system was applied. Meanwhile, patients' HCC samples and orthotopic xenograft mouse model were used for verifying our in vitro data. RESULTS ADAR1 p110 could strongly enhance the adhesion of HCC tumor cells to ECM, which was usually regarded as the initiation of tumor invasion. Such phenotype was caused due to up-regulation of ITGA2 both in mRNA and protein level. Moreover, specimen collected from HCC patients revealed a positive correlation between ADAR1 and ITGA2. Finally, ADAR1 p110 promoted HCC metastasis was verified when we applied orthotopic xenograft mouse model. CONCLUSIONS ADAR1 could enhance HCC metastasis by promoting tumor cells adhering to ECM via increasing ITGA2 expression. This phenomenon could provide novel information to better understanding the mechanism of HCC metastasis procedure.

Chinese Herbal Medicine Wenxia Changfu Formula Reverses Cell Adhesion-Mediated Drug Resistance via the Integrin β1-PI3K-AKT Pathway in Lung Cancer

In the treatment of lung cancer, the multidrug resistance to chemotherapeutic drugs is one of the reasons of low rates for cure and treatment failure, the combination of chemotherapeutic drugs and traditional Chinese medicine can increase the sensitivity of chemotherapy and reduce its adverse effects. Our previous study has proved that Chinese herbal medicine (CHM) Wenxia Changfu Formula (WCF for short) effectively enhances chemotherapeutic efficacy in lung cancer treatment and reverses multidrug resistance in lung cancer cells in vitro. The present study aims to investigate the effect and mechanism of WCF in reversing cell adhesion-mediated drug resistance of lung cancer by using A549 three-dimensional cell culture and nude mouse model of the A549 cell line with Integrin β1 overexpression. We show that the combination of WCF with DDP can decrease proliferation of lung cancer cells by inducing cell cycle arrest and apoptosis. Moreover, we find that the combination of WCF with DDP suppresses the expression of certain molecules which regulate cell cycle and apoptosis. Mechanistically, we show that the Integrin β1, FAK, PI3K, and AKT protein expressions are suppressed by DDP and even more responses are observed when DDP and WCF are combined, showing WCF treatment enhances the effect of commonly used anticancer drugs. In line with the above findings, our results confirm that WCF reverses cell adhesion-mediated drug resistance of lung cancer via inactivating Integrin β1/PI3K/AKT and apoptosis induction.

Regulation and functions of integrin α2 in cell adhesion and disease

Integrins are cell adhesion molecules that are composed of an alpha (α) subunit and a beta (β) subunit with affinity for different extracellular membrane components. The integrin family includes 24 known members that actively regulate cellular growth, differentiation, and apoptosis. Each integrin heterodimer has a particular function in defined contexts as well as some partially overlapping features with other members in the family. As many reviews have covered the general integrin family in molecular and cellular studies in life science, this review will focus on the specific regulation, function, and signaling of integrin α2 subunit (CD49b, VLA-2; encoded by the gene ITGA2) in partnership with β1 (CD29) subunit in normal and cancer cells. Its roles in cell adhesion, cell motility, angiogenesis, stemness, and immune/blood cell regulations are discussed. The pivotal role of integrin α2 in many diseases such as cancer suggests its potential to be used as a novel therapeutic target.

Is Integrin Subunit Alpha 2 Expression a Prognostic Factor for Liver Carcinoma? A Validation Experiment Based on Bioinformatics Analysis

ITGA2 (Integrin alpha-2) has been detected to be over-expressed in a number of cancers and has been suggested to be involved in cell adhesion and cell-surface mediated signaling. Our previous study using bioinformatic analyses has shown that ITGA2 might be a key gene being involved in the Cadmium-induced malignant transformation of liver cells. In the present study, we firstly aimed to learn the possible functions of ITGA2 via bioinformatics analysis, and then test its expression and clinical significance in liver carcinoma specimens through laboratory experiments. Gene ontology (GO) and pathway enrichment analysis, as well as protein-protein interaction (PPI) analysis has been conducted in Genecards. Then, a tissue microarray containing 90 cases of liver cancer and 90 paired adjacent non-cancerous samples was used for detection of ITGA2 expression by immunohistochemistry assay. Consequently, ITGA2 may be enriched in pathways regarding cell adhesion and migration. PPI analysis suggests that ITGA1, ITGB2, FLT4, LAMB1 and AGRN may have a close relationship with ITGA2. No association between ITGA2 expression and clinical parameters was observed. However, the data showed that ITGA2 might be an independent prognostic factor for liver cancer patients. In conclusion, the data suggest that ITGA2 over-expression might be a potential unfavorable prognostic factor and a potential therapeutic target for liver carcinoma.

Methylation-independent ITGA2 overexpression is associated with poor prognosis in de novo acute myeloid leukemia

Previous studies have been indicated that integrin α2 (ITGA2) may be important in cell migration, invasion, survival, and angiogenesis. However, the correlation between ITGA2 expression and acute myeloid leukemia (AML) is still unclear. Real-time quantitative polymerase chain reaction was carried out to analyze ITGA2 messenger RNA level. Methylation-specific polymerase chain reaction (PCR) and bisulfite sequencing PCR were performed to detect the methylation of ITGA2 promoter. ITGA2 expression was significantly upregulated in 134 de novo AML patients compared with 33 controls (p = 0.007). ITGA2^high group had markedly lower complete remission (CR) rate than ITGA2^low group (p = 0.011). Furthermore, the overall survival in ITGA2^high patients was significantly shorter than ITGA2^low patients throughout AML cohort, non-acute promyelocytic leukemia (APL) and cytogenetic normal-AML (p = 0.001, 0.002, and 0.044, respectively). Multivariate analysis confirmed that ITGA2 overexpression served as an independent prognostic factor in both whole-cohort AML patients (p = 0.018) and non-APL AML patients (p = 0.021). Besides, ITGA2 expression level was significantly decreased in AML patients after CR (p = 0.011), and was returned at the time of relapse phase (p = 0.021). Moreover, unmethylated ITGA2 promoter was identified in normal controls, leukemia cell lines, and primary leukemia cells with low or high ITGA2 expression. In conclusions, methylation-independent ITGA2 overexpression is associated with poor prognosis in AML.

Yes-associated protein (YAP) in pancreatic cancer: at the epicenter of a targetable signaling network associated with patient survival

Pancreatic ductal adenocarcinoma (PDAC) is generally a fatal disease with no efficacious treatment modalities. Elucidation of signaling mechanisms that will lead to the identification of novel targets for therapy and chemoprevention is urgently needed. Here, we review the role of Yes-associated protein (YAP) and WW-domain-containing Transcriptional co-Activator with a PDZ-binding motif (TAZ) in the development of PDAC. These oncogenic proteins are at the center of a signaling network that involves multiple upstream signals and downstream YAP-regulated genes. We also discuss the clinical significance of the YAP signaling network in PDAC using a recently published interactive open-access database (www.proteinatlas.org/pathology) that allows genome-wide exploration of the impact of individual proteins on survival outcomes. Multiple YAP/TEAD-regulated genes, including AJUBA, ANLN, AREG, ARHGAP29, AURKA, BUB1, CCND1, CDK6, CXCL5, EDN2, DKK1, FOSL1,FOXM1, HBEGF, IGFBP2, JAG1, NOTCH2, RHAMM, RRM2, SERP1, and ZWILCH, are associated with unfavorable survival of PDAC patients. Similarly, components of AP-1 that synergize with YAP (FOSL1), growth factors (TGFα, EPEG, and HBEGF), a specific integrin (ITGA2), heptahelical receptors (P2Y₂R, GPR87) and an inhibitor of the Hippo pathway (MUC1), all of which stimulate YAP activity, are associated with unfavorable survival of PDAC patients. By contrast, YAP inhibitory pathways (STRAD/LKB-1/AMPK, PKA/LATS, and TSC/mTORC1) indicate a favorable prognosis. These associations emphasize that the YAP signaling network correlates with poor survival of pancreatic cancer patients. We conclude that the YAP pathway is a major determinant of clinical aggressiveness in PDAC patients and a target for therapeutic and preventive strategies in this disease.

Yes-associated protein (YAP) signaling contributes to pancreatic cancer progression and is associated with poor patient survival. Previous studies have shown that YAP activates genes involved in cell proliferation to incite tumor growth and metastasis. Enrique Rozengurt and colleagues at University of California Los Angeles review the latest knowledge on YAP signaling and used the open access database The Human Protein Atlas to analyze the gene expression profile and prognosis of 176 patients with pancreatic ductal adenocarcinoma. Activation of upstream or downstream elements of the YAP signaling pathway correlated with shorter survival in patients. Conversely, the activation of signaling pathways that oppose YAP signaling were associated with a more favorable prognosis. These findings highlight YAP signaling pathway components as both prognostic markers and potential targets for developing much needed therapeutic and preventative strategies.

YAP/TAZ Activation as a Target for Treating Metastatic Cancer

Yes-Associated Protein (YAP) and Transcriptional Co-activator with PDZ-binding Motif (TAZ) have both emerged as important drivers of cancer progression and metastasis. YAP and TAZ are often upregulated or nuclear localized in aggressive human cancers. There is abundant experimental evidence demonstrating that YAP or TAZ activation promotes cancer formation, tumor progression, and metastasis. In this review we summarize the evidence linking YAP/TAZ activation to metastasis, and discuss the roles of YAP and TAZ during each step of the metastatic cascade. Collectively, this evidence strongly suggests that inappropriate YAP or TAZ activity plays a causal role in cancer, and that targeting aberrant YAP/TAZ activation is a promising strategy for the treatment of metastatic disease. To this end, we also discuss several potential strategies for inhibiting YAP/TAZ activation in cancer and the challenges each strategy poses.

Identification of Novel Response and Predictive Biomarkers to Hsp90 Inhibitors Through Proteomic Profiling of Patient-derived Prostate Tumor Explants

Inhibition of the heat shock protein 90 (Hsp90) chaperone is a promising therapeutic strategy to target expression of the androgen receptor (AR) and other oncogenic drivers in prostate cancer cells. However, identification of clinically-relevant responses and predictive biomarkers is essential to maximize efficacy and treatment personalization. Here, we combined mass spectrometry (MS)-based proteomic analyses with a unique patient-derived explant (PDE) model that retains the complex microenvironment of primary prostate tumors. Independent discovery and validation cohorts of PDEs (n = 16 and 30, respectively) were cultured in the absence or presence of Hsp90 inhibitors AUY922 or 17-AAG. PDEs were analyzed by LC-MS/MS with a hyper-reaction monitoring data independent acquisition (HRM-DIA) workflow, and differentially expressed proteins identified using repeated measure analysis of variance (ANOVA; raw p value <0.01). Using gene set enrichment, we found striking conservation of the most significantly AUY922-altered gene pathways between the discovery and validation cohorts, indicating that our experimental and analysis workflows were robust. Eight proteins were selectively altered across both cohorts by the most potent inhibitor, AUY922, including TIMP1, SERPINA3 and CYP51A (adjusted p < 0.01). The AUY922-mediated decrease in secretory TIMP1 was validated by ELISA of the PDE culture medium. We next exploited the heterogeneous response of PDEs to 17-AAG in order to detect predictive biomarkers of response and identified PCBP3 as a marker with increased expression in PDEs that had no response or increased in proliferation. Also, 17-AAG treatment led to increased expression of DNAJA1 in PDEs that exhibited a cytostatic response, revealing potential drug resistance mechanisms. This selective regulation of DNAJA1 was validated by Western blot analysis. Our study establishes "proof-of-principle" that proteomic profiling of drug-treated PDEs represents an effective and clinically-relevant strategy for identification of biomarkers that associate with certain tumor-specific responses.

Identification and Characterization of Cadmium-Related Genes in Liver Carcinoma

Evidence indicates that exposure to heavy trace element might be a risk factor for liver carcinoma. Cadmium has been supposed to be a carcinogen that has a correlation with the risk of a number of cancers, including liver cancer. However, the mechanisms underlying Cadmium-induced malignant transformation in liver cells are not fully understood. In the present study, we aimed to screen the differentially expressed genes (DEGs) that might play a role in both the Cadmium-related liver cell transformation and the development of liver cancer. Microarray-based gene expression profiles concerning liver carcinoma vs non-cancerous tissue (GSE64041) and Cadmium-treated liver cells vs controls (GSE8865 and GSE31286), respectively, were retrieved from Gene Expression Omnibus (GEO) database. Then, DEGs of each profile were calculated and screened. The intersection of each DEGs was obtained by Venn analysis. Afterwards, the possible roles of the selected genes in cancer development were evaluated by using Oncomine database and TCGA cohort analysis. Consequently, three DEGs, LRAT, SLC7A11, and ITGA2, were selected for further analysis. SLC7A11 and ITGA2, but not LRAT, were upregulated in liver cancer compared with those in normal tissues, respectively. After using a TCGA cohort analysis, results failed to show a significant correlation between SLC7A11 or ITGA2 expression and clinical parameters. However, the survival analysis showed that patients with high expression levels of SLC7A11 had a shorter overall survival time relative to those of the patients with low levels. In conclusion, SLC7A11 and ITGA2 might play a role in the Cadmium-induced liver cell damage or transformation, and the development of liver carcinoma. SLC7A11 might be a prognostic factor for patients with liver carcinoma. Future validation experiments are needed to verify the results.

Linking Extracellular Matrix Agrin to the Hippo Pathway in Liver Cancer and Beyond

In addition to the structural and scaffolding role, the extracellular matrix (ECM) is emerging as a hub for biomechanical signal transduction that is frequently relayed to intracellular sensors to regulate diverse cellular processes. At a macroscopic scale, matrix rigidity confers long-ranging effects contributing towards tissue fibrosis and cancer. The transcriptional co-activators YAP/TAZ, better known as the converging effectors of the Hippo pathway, are widely recognized for their new role as nuclear mechanosensors during organ homeostasis and cancer. Still, how YAP/TAZ senses these “stiffness cues” from the ECM remains enigmatic. Here, we highlight the recent perspectives on the role of agrin in mechanosignaling from the ECM via antagonizing the Hippo pathway to activate YAP/TAZ in the contexts of cancer, neuromuscular junctions, and cardiac regeneration.

Fibulin-5 promotes airway smooth muscle cell proliferation and migration via modulating Hippo-YAP/TAZ pathway

Asthma is a common chronic disease mainly occurs from childhood. Increased airway smooth muscle mass is involved in the pathogenesis of asthma. Fibulin-5 was upregulated in the lung tissues of patients with COPD and idiopathic pulmonary fibrosis. This study aimed to investigate Fibulin-5 expression in asthmatic patients and the effect and mechanism of Fibulin-5 on the proliferation and migration of airway smooth muscle cells (ASMCs). The expression of Fibulin-5, YAP, and TAZ in the induced sputum of 38 asthmatic children (19 mild and 19 moderate asthmatics) and 19 healthy controls was determined. The effects and mechanisms of Fibulin-5 on the proliferation and migration of ASMCs were analyzed through upregulating Fibulin-5. We found compared with healthy controls, the expression of Fibulin-5, YAP, and TAZ was increased in the induced sputum of asthmatic children and much higher in moderate asthmatics. Fibulin-5 overexpression promoted the proliferation and migration of ASMCs, upregulated the expression of YAP and TAZ, and reduced the levels of p-YAP and p-TAZ. YAP inhibitor (Peptide 17) abrogated the proliferation and migration of ASMCs induced by Fibulin-5 overexpression in a dose-dependent manner. Additionally, Fibulin-5 overexpression enhanced its binding capacity of β1 integrin, and β1 integrin blocking antibody partly reversed the effect of Fibulin-5 overexpression on the levels of YAP and TAZ. In conclusion, Fibulin-5 expression is correlated with the pathogenesis of childhood asthma. It may function at least partly through binding to β1 integrin and modulating Hippo-YAP/TAZ pathway to promote the proliferation and migration of ASMCs.

Identification of hub genes involved in the development of hepatocellular carcinoma by transcriptome sequencing

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death. The aim of this study was to identify underlying hub genes and dysregulated pathways associated with the development of HCC using bioinformatics analysis. Differentially expressed protein-coding genes were subjected to transcriptome sequencing in 11 pairs of liver cancer tissue and matched adjacent non-cancerous tissue. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed, followed by protein-protein interaction (PPI) network construction. Hub genes were identified via centralities analysis and verified using published datasets. In total, 720 significantly differentially expressed protein-coding genes were identified in the samples, including 335 upregulated genes and 385 downregulated genes. The upregulated genes were significantly enriched in cell adhesion, biological adhesion and cell-cell adhesion GO terms under biological process (BP). Conversely, the downregulated genes were significantly enriched in embryonic organ morphogenesis, embryonic organ development and embryonic morphogenesis. The KEGG pathway analysis showed that the upregulated genes were enriched in ECM-receptor interaction and focal adhesion pathways. Furthermore, the downregulated genes were enriched in the ErbB, VEGF and MAPK signaling pathways. The PPI network and centralities analysis suggested that ITGA2 and 12 alternate genes were significant hub genes. These findings improve current understanding of the molecular mechanisms underlying HCC development and may be helpful in identifying candidate molecular biomarkers for use in diagnosing, treating and monitoring the prognosis of HCC.

Glypican-3: A promising biomarker for hepatocellular carcinoma diagnosis and treatment

Liver cancer is the second leading cause of cancer-related deaths, and hepatocellular carcinoma (HCC) is the most common type. Therefore, molecular targets are urgently required for the early detection of HCC and the development of novel therapeutic approaches. Glypican-3 (GPC3), an oncofetal proteoglycan anchored to the cell membrane, is normally detected in the fetal liver but not in the healthy adult liver. However, in HCC patients, GPC3 is overexpressed at both the gene and protein levels, and its expression predicts a poor prognosis. Mechanistic studies have revealed that GPC3 functions in HCC progression by binding to molecules such as Wnt signaling proteins and growth factors. Moreover, GPC3 has been used as a target for molecular imaging and therapeutic intervention in HCC. To date, GPC3-targeted magnetic resonance imaging, positron emission tomography, and near-infrared imaging have been investigated for early HCC detection, and various immunotherapeutic protocols targeting GPC3 have been developed, including the use of humanized anti-GPC3 cytotoxic antibodies, treatment with peptide/DNA vaccines, immunotoxin therapies, and genetic therapies. In this review, we summarize the current knowledge regarding the structure, function, and biology of GPC3 with a focus on its clinical potential as a diagnostic molecule and a therapeutic target in HCC immunotherapy.

The essential role of YAP O-GlcNAcylation in high-glucose-stimulated liver tumorigenesis

O-GlcNAcylation has been implicated in the tumorigenesis of various tissue origins, but its function in liver tumorigenesis is not clear. Here, we demonstrate that O-GlcNAcylation can enhance the expression, stability and function of Yes-associated protein (YAP), the downstream transcriptional regulator of the Hippo pathway and a potent oncogenic factor in liver cancer. O-GlcNAcylation induces transformative phenotypes of liver cancer cells in a YAP-dependent manner. An O-GlcNAc site of YAP was identified at Thr241, and mutating this site decreased the O-GlcNAcylation, stability, and pro-tumorigenic capacities of YAP, while increasing YAP phosphorylation. Importantly, we found via in vitro cell-based and in vivo mouse model experiments that O-GlcNAcylation of YAP was required for high-glucose-induced liver tumorigenesis. Interestingly, a positive feedback between YAP and global cellular O-GlcNAcylation is also uncovered. We conclude that YAP O-GlcNAcylation is a potential therapeutic intervention point for treating liver cancer associated with high blood glucose levels and possibly diabetes.

Yap is a transcriptional factor involved in tumorigenesis. Here the authors show that a previously unknown post-translational modification of Yap, O-GlcNAcylation, increases its transcriptional activity and is required for high glucose-induced liver cancer development.

Integrin β1 is a critical effector in promoting metastasis and chemo-resistance of esophageal squamous cell carcinoma

Metastasis of esophageal squamous cell carcinoma (ESCC) remains a challenge in clinical practice. In this study, we clarified that integrin β1 (ITGB1) plays critical roles in the metastasis of ESCC. By analyzing the expression of integrin β1 in ESCC specimens, we found that the expression of this integrin was higher in malignant than in normal tissues and that this increase was associated with lymph node metastasis. Moreover, in vitro functional experiments demonstrated that deletion of integrin β1 impaired the motility of ESCC cells, and we also showed that integrin β1 deletion significantly inhibited metastases formation in the lungs and lymph nodes of two murine models. Mechanistically, integrin β1 promoted cellular motility by regulating the FAK-Rac1 signaling pathway. Finally, we found that blocking integrin β1 significantly impaired the resistance of ESCC cells to cisplatin (DDP) treatment based on in vitro and in vivo experiments. Overall, our data suggest that integrin β1 promotes metastasis and confers DDP resistance to ESCC, which provides experimental evidence for targeting this protein to treat ESCC in the future.