REGγ Controls Hippo Signaling and Reciprocal NF-κB-YAP Regulation to Promote Colon Cancer

New horizons in the mechanisms and therapeutic strategies for PD-L1 protein degradation in cancer

Programmed death-ligand 1 (PD-L1) has become a crucial focus in cancer immunotherapy considering it is found in many different cells. Cancer cells enhance the suppressive impact of programmed death receptor 1 (PD-1) through elevating PD-L1 expression, which allows them to escape immune detection. Although there have been significant improvements, the effectiveness of anti-PD-1/PD-L1 treatment is still limited to a specific group of patients. An important advancement in cancer immunotherapy involves improving the PD-L1 protein degradation. This review thoroughly examined the processes by which PD-L1 breaks down, including the intracellular pathways of ubiquitination-proteasome and autophagy-lysosome. In addition, the analysis revealed changes that affect PD-L1 stability, such as phosphorylation and glycosylation. The significant consequences of these procedures on cancer immunotherapy and their potential role in innovative therapeutic approaches are emphasised. Our future efforts will focus on understanding new ways in which PD-L1 degradation is controlled and developing innovative treatments, such as proteolysis-targeting chimeras designed specifically to degrade PD-L1. It is crucial to have a thorough comprehension of these pathways in order to improve cancer immunotherapy strategies and hopefully improve therapeutic effectiveness.

Erlotinib suppresses tumorigenesis in a mouse model of colitis-associated cancer

Colitis-associated cancer (CAC) in inflammatory bowel diseases exhibits more aggressive behavior than sporadic colorectal cancer; however, the molecular mechanisms remain unclear. No definitive preventative agent against CAC is currently established in the clinical setting. We investigated the molecular mechanisms of CAC in the azoxymethane/dextran sulfate sodium (AOM/DSS) mouse model and assessed the antitumor efficacy of erlotinib, a small molecule inhibitor of the epidermal growth factor receptor (EGFR). Erlotinib premixed with AIN-93 G diet at 70 or 140 parts per million (ppm) inhibited tumor multiplicity significantly by 96%, with ∼60% of the treated mice exhibiting zero polyps at 12 weeks. Bulk RNA-sequencing revealed more than a thousand significant gene alterations in the colons of AOM/DSS-treated mice, with KEGG enrichment analysis highlighting 46 signaling pathways in CAC development. Erlotinib altered several signaling pathways and rescued 40 key genes dysregulated in CAC, including those involved in the Hippo and Wnt signaling. These findings suggest that the clinically-used antitumor agent erlotinib might be repurposed for suppression of CAC, and that further studies are warranted on the crosstalk between dysregulated Wnt and EGFR signaling in the corresponding patient population.

Role of Hippo pathway dysregulation from gastrointestinal premalignant lesions to cancer

BACKGROUND

First identified in Drosophila melanogaster, the Hippo pathway is considered a major regulatory cascade controlling tissue homeostasis and organ development. Hippo signaling components include kinases whose activity regulates YAP and TAZ final effectors. In response to upstream stimuli, YAP and TAZ control transcriptional programs involved in cell proliferation, cytoskeletal reorganization and stemness.

MAIN TEXT

While fine tuning of Hippo cascade components is essential for maintaining the balance between proliferative and non-proliferative signals, pathway signaling is frequently dysregulated in gastrointestinal cancers. Also, YAP/TAZ aberrant activation has been described in conditions characterized by chronic inflammation that precede cancer development, suggesting a role of Hippo effectors in triggering carcinogenesis. In this review, we summarize the architecture of the Hippo pathway and discuss the involvement of signaling cascade unbalances in premalignant lesions of the gastrointestinal tract, providing a focus on the underlying molecular mechanisms.

CONCLUSIONS

The biology of premalignant Hippo signaling dysregulation needs further investigation in order to elucidate the evolutionary trajectories triggering cancer inititation and develop effective early therapeutic strategies targeting the Hippo/YAP pathway.

ApoM suppresses kidney renal clear cell carcinoma growth and metastasis via the Hippo-YAP signaling pathway

Renal cell carcinoma is one of the most common malignancies worldwide, and kidney renal clear cell carcinoma (KIRC) is the most common histopathological type of renal cell carcinoma. However, the mechanism of KIRC progression remains poorly understood. Apolipoprotein M (ApoM) is a plasma apolipoprotein and a member of the lipid transport protein superfamily. Lipid metabolism is essential for tumor progression, and its related proteins can be used as therapeutic targets for tumors. ApoM influences the development of several cancers, but its relationship with KIRC remains unclear. In this study, we aimed to investigate the biological function of ApoM in KIRC and to reveal its potential molecular mechanisms. We found that ApoM expression was significantly reduced in KIRC and was strongly correlated with patient prognosis. ApoM overexpression significantly inhibited KIRC cell proliferation in vitro, suppressed the epithelial mesenchymal transition (EMT) of KIRC cells, and decreased their metastatic capacity. Additionally, the growth of KIRC cells was inhibited by ApoM overexpression in vivo. In addition, we found that overexpression of ApoM in KIRC attenuated Hippo-YAP protein expression and YAP stability and thus inhibited KIRC growth and progression. Therefore, ApoM may be a potential target for the treatment of KIRC.

circFANCA accelerates the malignant process of OSCC by modulating miR-34a/PA28γ signaling

OBJECTIVES

To investigate the upstream regulatory molecules of proteasomal activator 28γ (PA28γ), and explore its specific regulatory mechanism and potential clinical significance in OSCC.

MATERIALS AND METHODS

qPCR was used to examine miR-34a, circFANCA and PSME3 expression. Western blotting was adopted to detect PA28γ expression. Transwell experiments were conducted to evaluate OSCC cell migration and invasion ability. FISH was used to evaluate the subcellular localization of circFANCA and miR-34a, and RNA pull-down verified the interaction between them. The expression of circFANCA and miR-34a in clinical cohorts was assessed by ISH, and the results were subjected to survival analysis using Kaplan-Meier analysis.

RESULTS

Here, we proved that miR-34a expression is lower in highly aggressive OSCC tissues and cell lines. Notably, miR-34a can downregulate PA28γ expression and inhibit OSCC invasion and migration. Next, we confirmed that circFANCA promoted OSCC cell metastatic ability by sponging miR-34a. Importantly, interfering with miR-34a rescued the malignant progression of OSCC induced by silencing circFANCA. Finally, clinical data showed lower miR-34a expression and higher circFANCA expression were associated with poor prognosis in OSCC patients.

CONCLUSION

The circFANCA/miR-34a/PA28γ axis facilitates the metastasis of OSCC, and circFANCA and miR-34a have potential to serve as prognostic markers for OSCC patients.

The role of 14-3-3 in the progression of vascular inflammation induced by lipopolysaccharide

OBJECTIVE

To explore the role of 14-3-3 protein and the Hippo and yes-associated protein 1 (YAP) signaling pathway in lipopolysaccharide (LPS)-induced vascular inflammation.

METHODS

Human umbilical vein endothelial cells (HUVECs) and C57B6 mice were treated with LPS to establish cell and animal models of vascular inflammation. Lentiviral transfection, Western blot, qPCR, immunofluorescence, immunohistochemistry, co-immunoprecipitation, and enzyme-linked immunosorbent assays were used to measure inflammatory factors and expression of 14-3-3 protein and phosphorylation of YAP at S127. HUVECs and C57B6 mice were pretreated with a YAP inhibitor, Verteporfin, to observe changes in YAP expression and downstream vascular inflammation.

RESULTS

LPS induced acute and chronic inflammatory responses in HUVECs and mice and upregulated the expression of several inflammatory factors. LPS also induced expression of 14-3-3 protein and phosphorylation of YAP at S127 in response to acute vascular inflammation and downregulated these markers in response to chronic vascular inflammation. Verteporfin reduced these LPS-induced effects on vascular inflammation.

CONCLUSION

In chronic vascular inflammation, 14-3-3 protein is downregulated, which promotes inflammation by increasing Hippo/YAP nuclear translocation.

Ring finger protein 128 promotes, rather than inhibits, colorectal cancer progression by regulating the Hippo signaling pathway

Background

Colorectal cancer is a common malignancy of the gastrointestinal tract, and its incidence and mortality rates have increased in recent years. RNF128 is an E3 ubiquitin ligase that plays an important role as a suppressor gene or oncogene in various cancers, but its mechanism in colorectal cancer is not yet clear. The aim of this study was to investigate the role and mechanism of RNF128 in colorectal cancer.

Methods

The expression of RNF128 in colorectal cancer tissues was assessed by immunohistochemistry and western blotting. The proliferation ability of colorectal cancer cells was measured by colony formation assay and CCK-8 assay, the migration and invasion ability of colorectal cancer cells was measured by wound healing assay and transwell assay, and the protein expression levels of the Hippo signaling pathway and its target gene were examined by western blotting. Immunoprecipitation was used to assess the interaction of RNF128 with MST. In vivo, a xenograft tumor model was used to detect the effect of RNF128 on tumor growth.

Results

At the tissue level, the expression level of RNF128 was significantly higher in colorectal cancer tissues than in adjacent normal tissues. In LoVo cells and HCT116 cells, the proliferation, migration and invasion abilities were significantly reduced with RNF128 knockdown. At the protein level, knockdown of RNF128 resulted in significant activation of the Hippo signaling pathway. In vivo experiments, the volume and weight of xenograft tumors in nude mice were significantly decreased compared with those in the normal control group with RNF128 knockdown.

Conclusion

RNF128 promotes the malignant behaviors of colorectal cancer cells by inhibiting the Hippo signaling pathway, which may provide a new target for colorectal cancer prevention and treatment.

YAP promotes cell-autonomous immune responses to tackle intracellular Staphylococcus aureus in vitro

Transcriptional cofactors YAP/TAZ have recently been found to support autophagy and inflammation, which are part of cell-autonomous immunity and are critical in antibacterial defense. Here, we studied the role of YAP against Staphylococcus aureus using CRISPR/Cas9-mutated HEK293 cells and a primary cell-based organoid model. We found that S. aureus infection increases YAP transcriptional activity, which is required to reduce intracellular S. aureus replication. A 770-gene targeted transcriptomic analysis revealed that YAP upregulates genes involved in autophagy/lysosome and inflammation pathways in both infected and uninfected conditions. The YAP-TEAD transcriptional activity promotes autophagic flux and lysosomal acidification, which are then important for defense against intracellular S. aureus. Furthermore, the staphylococcal toxin C3 exoenzyme EDIN-B was found effective in preventing YAP-mediated cell-autonomous immune response. This study provides key insights on the anti-S. aureus activity of YAP, which could be conserved for defense against other intracellular bacteria.

Regulation of Life & Death by REGγ

REGγ, a proteasome activator belonging to the 11S (otherwise known as REG, PA28, or PSME) proteasome activator family, is widely present in many eukaryotes. By binding to the 20S catalytic core particle, REGγ acts as a molecular sieve to selectively target proteins for degradation in an ATP- and ubiquitin-independent manner. This non-canonical proteasome pathway directly regulates seemingly unrelated cellular processes including cell growth and proliferation, apoptosis, DNA damage response, immune response, and metabolism. By affecting different pathways, REGγ plays a vital role in the regulation of cellular life and death through the maintenance of protein homeostasis. As a promoter of cellular growth and a key regulator of several tumor suppressors, many recent studies have linked REGγ overexpression with tumor formation and suggested the REGγ-proteasome as a potential target of new cancer-drug development. This review will present an overview of the major functions of REGγ as it relates to the regulation of cellular life and death, along with new mechanistic insights into the regulation of REGγ.

Chemically Induced Colitis-Associated Cancer Models in Rodents for Pharmacological Modulation: A Systematic Review

Animal models for colitis-associated colorectal cancer (CACC) represent an important tool to explore the mechanistic basis of cancer-related inflammation, providing important evidence that several inflammatory mediators play specific roles in the initiation and perpetuation of colitis and CACC. Although several original articles have been published describing the CACC model in rodents, there is no consensus about the induction method. This review aims to identify, summarize, compare, and discuss the chemical methods for the induction of CACC through the PRISMA methodology.

METHODS

We searched MEDLINE via the Pubmed platform for studies published through March 2021, using a highly sensitive search expression. The inclusion criteria were only original articles, articles where a chemically-induced animal model of CACC is described, preclinical studies in vivo with rodents, and articles published in English.

RESULTS

Chemically inducible models typically begin with the administration of a carcinogenic compound (as azoxymethane (AOM) or 1,2-dimethylhydrazine (DMH)), and inflammation is caused by repeated cycles of colitis-inducing agents (such as 2,4,6-trinitrobenzenesulfonic acid (TNBS) or dextran sulfate sodium (DSS)). The strains mostly used are C57BL/6 and Balb/c with 5-6 weeks. To characterize the preclinical model, the parameters more used include body weight, stool consistency and morbidity, inflammatory biomarkers such as tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1β, angiogenesis markers such as proliferating cell nuclear antigen (PCNA), marker of proliferation Ki-67, and caspase 3, the presence of ulcers, thickness or hyperemia in the colon, and histological evaluation of inflammation.

CONCLUSION

The AOM administration seems to be important to the CACC induction method, since the carcinogenic effect is achieved with just one administration. DSS has been the more used inflammatory agent; however, the TNBS contribution should be more studied, since it allows a reliable, robust, and a highly reproducible animal model of intestinal inflammation.

YAP Transcriptional Activity Dictates Cell Response to TNF In Vitro

YAP/TAZ are transcription co-factors recently described responsive to pro-inflammatory cytokines and involved in inflammatory-related disorders. However, the role of tumor necrosis factor (TNF), a major pro-inflammatory cytokine, on YAP signaling is not well understood and controversial. Here, we observe in vitro, using wild type and YAP knockout HEK293 cells, that TNF triggers YAP nuclear translocation and transcriptional activity, thus being dependent on Rho family of GTPases. In response to TNF, YAP transcriptional activity orientates cell fate toward survival. Transcriptional analysis with Nanostring technology reveals that YAP modulates TNF-induced increase in fibro-inflammatory pathways such as NF-κB, inflammasomes, cytokines or chemokines signaling and pro-fibrotic pathways involving TGF-β and extracellular matrix remodeling. Therefore, in response to TNF, YAP acts as a sustainer of the inflammatory response and as a molecular link between inflammation and fibrotic processes. This work identifies that YAP is critical to drive several biological effects of TNF which are involved in cancer and inflammatory disorders.

CARMA3 Promotes Colorectal Cancer Cell Motility and Cancer Stemness via YAP-Mediated NF-κB Activation

Simple Summary

CARMA3 is overexpressed in most cancers, and its expression is positively associated with poor prognosis. In this study, we evaluated the detailed mechanisms of CARMA3-mediated CRC metastasis. We found that overexpression of CARMA3 induced the expression of YAP and NF-κB activation, then elicited EMT induction to enhance cell migration and invasion. We demonstrate for the first time that YAP is a critical downstream regulator of CARMA3 in CRC. Our findings reveal a regulation axis between CARMA3 and Hippo oncoprotein YAP and further support the potential role of CARMA3 in the metastasis and cancer stemness of CRC.

Abstract

CARD-recruited membrane-associated protein 3 (CARMA3) is overexpressed in various cancers and is associated with cancer cell proliferation, metastasis, and tumor progression; however, the underlying mechanisms of CARMA3 in colorectal cancer (CRC) metastasis remain unclear. Here, we found that higher CARMA3 expression was correlated with poor overall survival and metastasis in CRC patients from the TNMplot database and Human Tissue Microarray staining. Elevating CARMA3 expression promoted cell proliferation, epithelial-mesenchymal transition (EMT) induction, migration/invasion abilities, sphere formation, and cancer stem cell markers expression. Knockdown of CARMA3 decreased these processes via the EMT-related transcription factor Slug. Moreover, CARMA3 depletion significantly reduced tumor growth in mice that were consistent with the in vitro results. CRC migration/invasion could be regulated by CARMA3/YAP/Slug signaling axis using genetic inhibition of Yes-associated protein (YAP). Interestingly, CARMA3 induced activation of nuclear factor (NF)-κB through YAP expression, contributing to upregulation of Slug. YAP expression positively correlated with CARMA3, NF-κB, and Slug gene expression and poor clinical outcomes in CRC patients. Our findings demonstrate for the first time that CARMA3 plays an important role in CRC progression, which may serve as a potential diagnostic biomarker and candidate therapeutic target for CRC treatment.

REGγ drives Lgr5+ stem cells to potentiate radiation induced intestinal regeneration

Leucine-rich repeat containing G protein-coupled receptor 5 (Lgr5), a marker of intestinal stem cells (ISCs), is considered to play key roles in tissue homoeostasis and regeneration after acute radiation injury. However, the activation of Lgr5 by integrated signaling pathways upon radiation remains poorly understood. Here, we show that irradiation of mice with whole-body depletion or conditional ablation of REGγ in Lgr5⁺ stem cell impairs proliferation of intestinal crypts, delaying regeneration of intestine epithelial cells. Mechanistically, REGγ enhances transcriptional activation of Lgr5 via the potentiation of both Wnt and Hippo signal pathways. TEAD4 alone or cooperates with TCF4, a transcription factor mediating Wnt signaling, to enhance the expression of Lgr5. Silencing TEAD4 drastically attenuated β-catenin/TCF4 dependent expression of Lgr5. Together, our study reveals how REGγ controls Lgr5 expression and expansion of Lgr5⁺ stem cells in the regeneration of intestinal epithelial cells. Thus, REGγ proteasome appears to be a potential therapeutic target for radiation-induced gastrointestinal disorders.

The Interaction between microRNAs and the Wnt/β-Catenin Signaling Pathway in Osteoarthritis

Osteoarthritis (OA) is a chronic disease affecting the whole joint, which still lacks a disease-modifying treatment. This suggests an incomplete understanding of underlying molecular mechanisms. The Wnt/β-catenin pathway is involved in different pathophysiological processes of OA. Interestingly, both excessive stimulation and suppression of this pathway can contribute to the pathogenesis of OA. microRNAs have been shown to regulate different cellular processes in different diseases, including the metabolic activity of chondrocytes and osteocytes. To bridge these findings, here we attempt to give a conclusive overview of microRNA regulation of the Wnt/β-catenin pathway in bone and cartilage, which may provide insights to advance the development of miRNA-based therapeutics for OA treatment.

YAP prevents premature senescence of astrocytes and cognitive decline of Alzheimer's disease through regulating CDK6 signaling

Senescent astrocytes accumulate with aging and contribute to brain dysfunction and diseases such as Alzheimer's disease (AD), however, the mechanisms underlying the senescence of astrocytes during aging remain unclear. In the present study, we found that Yes‐associated Protein (YAP) was downregulated and inactivated in hippocampal astrocytes of aging mice and AD model mice, as well as in D‐galactose and paraquat‐induced senescent astrocytes, in a Hippo pathway‐dependent manner. Conditional knockout of YAP in astrocytes significantly promoted premature senescence of astrocytes, including reduction of cell proliferation, hypertrophic morphology, increase in senescence‐associated β‐galactosidase activity, and upregulation of several senescence‐associated genes such as p16, p53 and NF‐κB, and downregulation of Lamin B1. Further exploration of the underlying mechanism revealed that the expression of cyclin‐dependent kinase 6 (CDK6) was decreased in YAP knockout astrocytes in vivo and in vitro, and ectopic overexpression of CDK6 partially rescued YAP knockout‐induced senescence of astrocytes. Finally, activation of YAP signaling by XMU‐MP‐1 (an inhibitor of Hippo kinase MST1/2) partially rescued the senescence of astrocytes and improved the cognitive function of AD model mice and aging mice. Taken together, our studies identified unrecognized functions of YAP‐CDK6 pathway in preventing astrocytic senescence in vitro and in vivo, which may provide further insights and new targets for delaying brain aging and aging‐related neurodegenerative diseases such as AD.

Combination of Melatonin and Zoledronic Acid Suppressed the Giant Cell Tumor of Bone in vitro and in vivo

Melatonin (Mlt) confers potential antitumor effects in various types of cancer. However, to the best of our knowledge, the role of Mlt in the giant cell tumor of bone (GCTB) remains unknown. Moreover, further research is required to assess whether Mlt can enhance the therapeutic effect of zoledronic acid (Zol), a commonly used anti-GCTB drug. In this research, we investigated the effects of Mlt, Zol, and the combination of these two drugs on GCTB cells’ characteristics, including cell proliferation, apoptosis, osteogenic differentiation, migration, and invasion. The cell counting kit-8 (CCK-8) assay, colony formation assay, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay (TUNEL), alkaline phosphatase (ALP) staining, alizarin red staining (ARS), scratch wound healing assay, and transwell experiment were performed, respectively. Our results showed that Mlt could effectively inhibit the proliferation, migration, and invasion of GCTB cells, as well as promote the apoptosis and osteogenic differentiation of tumor cells. Of note, a stronger antitumor effect was observed when Mlt was combined with Zol treatment. This therapeutic effect might be achieved by inhibiting the activation of both the Hippo and NF-κB pathways. In conclusion, our study suggests that Mlt can be a new treatment for GCTB, which could further enhance the antitumor effect of Zol.

Pharmacological inhibition of MELK restricts ferroptosis and the inflammatory response in colitis and colitis-propelled carcinogenesis

INTRODUCTION

Inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), is a group of chronic recurrent and incurable gastrointestinal diseases with an unknown etiology that leads to a high risk of developing colitis-associated colorectal cancer (CRC).

OBJECTIVES

In this study, we measured the expression characteristics of MELK in IBD and CRC tissues and explored the regulatory effect of OTSSP167 (a MELK-selective inhibitor) on the mice models of colitis and colitis-associated carcinogenesis and analyzed the specific molecular mechanisms.

METHODS

DSS-induced colitis and colitis-associated carcinogenesis (CAC) model were treated with MELK inhibitor OTSSP167 then the fight against effect of OTSSP167 in the clinical symptoms of colitis and CAC was measured. In addition, underlying mechanism of OTSSP167 treatment in vitro and vivo including anti-ferroptosis and anti-inflammatory response effect was further explored.

RESULTS

We found that pharmacological inhibition of MELK was indicated to significantly alleviate the inflammatory response in mice with colitis, reduce intestinal damage, and effectively inhibit the occurrence and progression of colitis-propelled carcinogenesis, which was closely related to the regulation of gut microbial composition, and OTSSP167-mediated fecal microbiota transplantation effectively alleviated DSS-induced colitis. In addition, OTSSP167 treatment obviously inhibited ferroptosis in the intestinal tissue and suppressed macrophage infiltration and M1 polarization, which reduced the secretion of pro-inflammatory factors. Further exploration of the molecular mechanism revealed that OTSSP167 inhibited AKT/IKK/P65 and ERK/IKK/P65 signaling cascades both in vivo and in vitro, which may help alleviate intestinal inflammation and control the occurrence of cancer.

CONCLUSION

Our findings lay a theoretical foundation for the use of OTSSP167 as a treatment for IBD and its inhibition of the occurrence of colitis-associated carcinogenesis; additionally, MELK may be a potentially effective target molecule, thus providing more options for clinical treatment.

Role of sericin 1 in the immune system of silkworms revealed by transcriptomic and proteomic analyses after gene knockout

The domestic silkworm is a type of lepidopteran insect that feeds on mulberry leaves and has high economic value because of its ability to spin cocoons. Sericin 1 is an important component of silkworm cocoons, accounting for approximately 25% of the material. In this study, CRISPR/Cas9‐mediated gene editing was successfully used to destroy the sericin 1 gene, and homozygous mutants were obtained after continuous screening. Homozygous mutation resulted in premature termination of the translation of sericin 1 protein at 323 amino acids. Comparative transcriptomic and proteomic analyses of middle silk gland cells from wild‐type individuals and mutants were performed on the fourth day of the fifth instar, and the results suggest that sericin 1 plays an important role in the cellular immune system. In addition, the results suggest that sericin 1 has a synergistic effect with some protease inhibitors and that the secretion of these proteins is strictly regulated. These results will provide new insights into the function and expression pattern of sericin 1 and the mechanism of silk secretion.

The role of the Hippo pathway in the pathogenesis of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic and recurrent inflammatory disorder that primarily comprises Crohn's disease (CD) and ulcerative colitis (UC). Owing to its increasing prevalence in Eastern countries and the intractable challenges faced during IBD treatment, extensive research on IBD has been carried out over the last few years. Although the precise aetiology of IBD is undefined, the currently accepted hypothesis for IBD pathogenesis considers it to be a combination of environment, genetic predisposition, gut microbiota, and abnormal immunity. A recently emerged signalling pathway, the Hippo pathway, acts as a key regulator of cell growth, tissue homoeostasis, organ size, and has been implicated in several human cancers. In the past few years, studies have revealed the importance of the Hippo pathway in gastrointestinal tract physiology and gastrointestinal diseases, such as colorectal cancer and IBD. However, the role of the Hippo pathway and its exact impact in IBD remains to be elucidated. This review summarises the latest scientific literature on the involvement of this pathway in IBD from the following perspectives that account for the IBD pathogenesis: intestinal epithelial cell regeneration, immune regulation, gut microbiota, and angiogenesis. A comprehensive understanding of the specific role of the Hippo pathway in IBD will provide novel insights into future research directions and clinical implications of the Hippo pathway.

Reciprocal REGγ-mTORC1 regulation promotes glycolytic metabolism in hepatocellular carcinoma

Despite significant progression in the study of hepatocellular carcinoma (HCC), the role of the proteasome in regulating cross talk between mTOR signaling and glycolysis in liver cancer progression is not fully understood. Here, we demonstrate that deficiency of REGγ, a proteasome activator, in mice significantly attenuates DEN-induced liver tumor formation. Ablation of REGγ increases the stability of PP2Ac (protein phosphatase 2 catalytic subunit) in vitro and in vivo, which dephosphorylates PRAS40 (AKT1 substrate 1) and stabilizes the interaction between PRAS40 and Raptor to inactive mTORC1-mediated hyper-glycolytic metabolism. In the DEN-induced animal model and clinical hepato-carcinoma samples, high levels of REGγ in HCC tumor regions contribute to reduced expression of PP2Ac, leading to accumulation of phosphorylated PRAS40 and mTORC1-mediated activation of HIF1α. Interestingly, mTORC1 enhances REGγ activity in HCC, forming a positive feedback regulatory loop. In conclusion, our study identifies REGγ-PP2Ac-PRAS40 axis as a new layer in regulating mTORC1 activity and downstream glycolytic alterations during HCC development, highlighting the REGγ-proteasome as a potential target for personalized HCC therapy.

YAP/TAZ Signalling in Colorectal Cancer: Lessons from Consensus Molecular Subtypes

Simple Summary

Colorectal cancer (CRC) is a heterogeneous disease that can be divided into 4 consensus molecular subtypes (CMS) according to molecular profiling. The CMS classification is now considered as a reference framework for understanding the heterogeneity of CRC and for the implementation of precision medicine. Although the contribution of YAP/TAZ signalling to CRC has been intensively studied, there is little information on its role within each CMS subtype. This article aims to provide an overview of our knowledge of YAP/TAZ in CRC through the lens of the CMS classification.

Abstract

Recent advance in the characterization of the heterogeneity of colorectal cancer has led to the definition of a consensus molecular classification within four CMS subgroups, each associated with specific molecular and clinical features. Investigating the signalling pathways that drive colorectal cancer progression in relation to the CMS classification may help design therapeutic strategies tailored for each CMS subtype. The two main effectors of the Hippo pathway YAP and its paralogue TAZ have been intensively scrutinized for their contribution to colon carcinogenesis. Here, we review the knowledge of YAP/TAZ implication in colorectal cancer from the perspective of the CMS framework. We identify gaps in our current understanding and delineate research avenues for future work.

Aldo-keto reductase family 1 member B induces aortic valve calcification by activating hippo signaling in valvular interstitial cells

AIMS

Calcific aortic valve disease (CAVD) is a primary cause of cardiovascular mortality; however, its mechanisms are unknown. Currently, no effective pharmacotherapy is available for CAVD. Aldo-keto reductase family 1 member B (Akr1B1) has been identified as a potential therapeutic target for valve interstitial cell calcification. Herein, we hypothesized that inhibition of Akr1B1 can attenuate aortic valve calcification.

METHODS AND RESULTS

Normal and degenerative tricuspid calcific valves from human samples were analyzed by immunoblotting and immunohistochemistry. The results showed significant upregulation of Akr1B1 in CAVD leaflets. Akr1B1 inhibition attenuated calcification of aortic valve interstitial cells in osteogenic medium. In contrast, overexpression of Akr1B1 aggravated calcification in osteogenic medium. Mechanistically, using RNA sequencing (RNAseq), we revealed that Hippo-YAP signaling functions downstream of Akr1B1. Furthermore, we established that the protein level of the Hippo-YAP signaling effector active-YAP had a positive correlation with Akr1B1. Suppression of YAP reversed Akr1B1 overexpression-induced Runx2 upregulation. Moreover, YAP activated the Runx2 promoter through TEAD1 in a manner mediated by ChIP and luciferase reporter systems. Animal experiments showed that the Akr1B1 inhibitor epalrestat attenuated aortic valve calcification induced by a Western diet in LDLR^-/- mice.

CONCLUSION

This study demonstrates that inhibition of Akr1B1 can attenuate the degree of calcification both in vitro and in vivo. The Akr1B1 inhibitor epalrestat may be a potential treatment option for CAVD.

Role of oncogenic REGγ in cancer

Cancer is a critical global health-care problem with limited therapeutic options. Since cancers are life-threatening illnesses, the identification of a promising oncotarget and its clinical correlates are relevant. Mounting evidence has emerged indicating that REG gamma (REGγ), a member of the 11S proteasome activators, plays a pivotal role in the development of multiple human cancers. However, an elaborate summary on the association between REGγ and cancer is still lacking. In this Review, we discuss how REGγ, through its ATP- and ubiquitin-independent manners, represents a promising cancer biomarker and therapeutic oncotarget for multiple human cancers. Aberrant REGγ expression closely associated with tumorigenesis attributes to its biological functions for controlling and regulating cell cycle, proliferation, migration, invasion, angiogenesis, and metastasis of the cancer cells by degrading proteins of cytosol and nucleus in the eukaryotic cells. REGγ serves as a molecular switch to activate multifarious oncogenic signaling pathways, such as MAPK/p38, TGF-β/Smad, and Wnt/β-catenin. The review describes that targeting REGγ may provide new diagnostic and therapeutic applications in cancer.

The REGγ inhibitor NIP30 increases sensitivity to chemotherapy in p53-deficient tumor cells

A major challenge in chemotherapy is chemotherapy resistance in cells lacking p53. Here we demonstrate that NIP30, an inhibitor of the oncogenic REGγ-proteasome, attenuates cancer cell growth and sensitizes p53-compromised cells to chemotherapeutic agents. NIP30 acts by binding to REGγ via an evolutionarily-conserved serine-rich domain with 4-serine phosphorylation. We find the cyclin-dependent phosphatase CDC25A is a key regulator for NIP30 phosphorylation and modulation of REGγ activity during the cell cycle or after DNA damage. We validate CDC25A-NIP30-REGγ mediated regulation of the REGγ target protein p21 in vivo using p53-/- and p53/REGγ double-deficient mice. Moreover, Phosphor-NIP30 mimetics significantly increase the growth inhibitory effect of chemotherapeutic agents in vitro and in vivo. Given that NIP30 is frequently mutated in the TCGA cancer database, our results provide insight into the regulatory pathway controlling the REGγ-proteasome in carcinogenesis and offer a novel approach to drug-resistant cancer therapy.

A Driver Never Works Alone-Interplay Networks of Mutant p53, MYC, RAS, and Other Universal Oncogenic Drivers in Human Cancer

The knowledge accumulating on the occurrence and mechanisms of the activation of oncogenes in human neoplasia necessitates an increasingly detailed understanding of their systemic interactions. None of the known oncogenic drivers work in isolation from the other oncogenic pathways. The cooperation between these pathways is an indispensable element of a multistep carcinogenesis, which apart from inactivation of tumor suppressors, always includes the activation of two or more proto-oncogenes. In this review we focus on representative examples of the interaction of major oncogenic drivers with one another. The drivers are selected according to the following criteria: (1) the highest frequency of known activation in human neoplasia (by mutations or otherwise), (2) activation in a wide range of neoplasia types (universality) and (3) as a part of a distinguishable pathway, (4) being a known cause of phenotypic addiction of neoplastic cells and thus a promising therapeutic target. Each of these universal oncogenic factors—mutant p53, KRAS and CMYC proteins, telomerase ribonucleoprotein, proteasome machinery, HSP molecular chaperones, NF-κB and WNT pathways, AP-1 and YAP/TAZ transcription factors and non-coding RNAs—has a vast network of molecular interrelations and common partners. Understanding this network allows for the hunt for novel therapeutic targets and protocols to counteract drug resistance in a clinical neoplasia treatment.

Tubule-Specific Mst1/2 Deficiency Induces CKD via YAP and Non-YAP Mechanisms

BACKGROUND

The serine/threonine kinases MST1 and MST2 are core components of the Hippo pathway, which has been found to be critically involved in embryonic kidney development. Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) are the pathway's main effectors. However, the biologic functions of the Hippo/YAP pathway in adult kidneys are not well understood, and the functional role of MST1 and MST2 in the kidney has not been studied.

METHODS

We used immunohistochemistry to examine expression in mouse kidneys of MST1 and MST2, homologs of Hippo in Drosophila. We generated mice with tubule-specific double knockout of Mst1 and Mst2 or triple knockout of Mst1, Mst2, and Yap. PCR array and mouse inner medullary collecting duct cells were used to identify the primary target of Mst1/Mst2 deficiency.

RESULTS

MST1 and MST2 were predominantly expressed in the tubular epithelial cells of adult kidneys. Deletion of Mst1/Mst2 in renal tubules increased activity of YAP but not TAZ. The kidneys of mutant mice showed progressive inflammation, tubular and glomerular damage, fibrosis, and functional impairment; these phenotypes were largely rescued by deletion of Yap in renal tubules. TNF-α expression was induced via both YAP-dependent and YAP-independent mechanisms, and TNF-α and YAP amplified the signaling activities of each other in the tubules of kidneys with double knockout of Mst1/Mst2.

CONCLUSIONS

Our findings show that tubular Mst1/Mst2 deficiency leads to CKD through both the YAP and non-YAP pathways and that tubular YAP activation induces renal fibrosis. The pathogenesis seems to involve the reciprocal stimulation of TNF-α and YAP signaling activities.

Proteasome-dependent degradation of Smad7 is critical for lung cancer metastasis

Lung cancer is one of the cancers with highest morbidity and mortality rates and the metastasis of lung cancer is a leading cause of death. Mechanisms of lung cancer metastasis are yet to be fully understood. Herein, we demonstrate that mice deficient for REGγ, a proteasome activator, exhibited a significant reduction in tumor size, numbers, and metastatic rate with prolonged survival in a conditional Kras/p53 mutant lung cancer model. REGγ enhanced the TGFβ-Smad signaling pathway by ubiquitin-ATP-independent degradation of Smad7, an inhibitor of the TGFβ pathway. Activated TGFβ signaling in REGγ-positive lung cancer cells led to diminished expression of E-cadherin, a biomarker of epithelial-mesenchymal transitions (EMT), and elevated mesenchymal markers compared with REGγ-deficient lung cancer cells. REGγ overexpression was found in lung cancer patients with metastasis, correlating with the reduction of E-Cadherin/Smad7 and a poor prognosis. Overall, our study indicates that REGγ promotes lung cancer metastasis by activating TGF-β signaling via degradation of Smad7. Thus, REGγ may serve as a novel therapeutic target for lung cancers with poor prognosis.

Human Colorectal Cancer from the Perspective of Mouse Models

Colorectal cancer (CRC) is a heterogeneous disease that includes both hereditary and sporadic types of tumors. Tumor initiation and growth is driven by mutational or epigenetic changes that alter the function or expression of multiple genes. The genes predominantly encode components of various intracellular signaling cascades. In this review, we present mouse intestinal cancer models that include alterations in the Wnt, Hippo, p53, epidermal growth factor (EGF), and transforming growth factor β (TGFβ) pathways; models of impaired DNA mismatch repair and chemically induced tumorigenesis are included. Based on their molecular biology characteristics and mutational and epigenetic status, human colorectal carcinomas were divided into four so-called consensus molecular subtype (CMS) groups. It was shown subsequently that the CMS classification system could be applied to various cell lines derived from intestinal tumors and tumor-derived organoids. Although the CMS system facilitates characterization of human CRC, individual mouse models were not assigned to some of the CMS groups. Thus, we also indicate the possible assignment of described animal models to the CMS group. This might be helpful for selection of a suitable mouse strain to study a particular type of CRC.

Downregulated miR-585-3p promotes cell growth and proliferation in colon cancer by upregulating PSME3

Background

Upregulation of PSME3 and its oncogenic roles have been reported in colon cancer recently. However, the underlying mechanism of PSME3 upregulation remains unknown. Here, we explored the expression of PSME3 and subsequently uncovered its mechanism in colon cancer.

Materials and methods

The expression of PSME3 was analyzed by using online databases, Oncomine and UALCAN. qPCR was carried out to detect the expression of PSME3 in collected colon cancer tissues and cell lines. Moreover, the promoter methylation and the hnRNA level of PSME3 were also analyzed by online database and qPCR, respectively. The candidate miRNAs targeting PSME3 were predicted by Starbase 3.0 and validated by luciferase reporter system. CCK-8, plate colon formation, and Edu incorporation were applied to study the functions of miRNA in colon cancer. The expression of miRNA and its correlation with PSME3 were detected in colon cancer tissues.

Results

Oncomine and UALCAN data indicate PSME3 is obviously upregulated in colon cancer tissue samples which is further confirmed in collected colon cancer tissues and cells by qPCR. No significant difference in methylation status promoter of PSME3 was observed between colon and colon cancer tissues. The hnRNA level of PSME3 was comparable between colon epithelial cell and colon cancer cells. miR-585-3p is predicted to directly target PSME3 and is validated by luciferase reporter assay. Then, miR-585-3p downregulation is confirmed and miR-585-3p restoration can suppress cell growth and proliferation by inhibiting PSME3 in colon cancer indicating by CCK-8, plate colon formation, and Edu incorporation. Moreover, negative correlation in expression between miR-585-3p and PSME3 was observed in our collected tissues samples.

Conclusion

We reveal for the first time that miR-585-3p downregulation accounts for the overexpression of PSME3 in colon cancer. Moreover, miR-585-3p, serving as a tumor suppressor, can inhibit cell growth and proliferation in colon cancer by targeting PSME3.

CSCs in Breast Cancer-One Size Does Not Fit All: Therapeutic Advances in Targeting Heterogeneous Epithelial and Mesenchymal CSCs

Unlike other breast cancer subtypes, triple-negative breast cancer (TNBC) has no specific targets and is characterized as one of the most aggressive subtypes of breast cancer that disproportionately accounts for the majority of breast cancer-related deaths. Current conventional chemotherapeutics target the bulk tumor population, but not the cancer stem cells (CSCs) that are capable of initiating new tumors to cause disease relapse. Recent studies have identified distinct epithelial-like (E) ALDH⁺ CSCs, mesenchymal-like (M) CD44⁺/CD24^- CSCs, and hybrid E/M ALDH⁺/CD44⁺/CD24^- CSCs. These subtypes of CSCs exhibit differential signal pathway regulations, possess plasticity, and respond differently to treatment. As such, co-inhibition of different subtypes of CSCs is key to viable therapy. This review serves to highlight different pathway regulations in E and M CSCs in TNBC, and to further describe their role in disease progression. Potential inhibitors targeting E and/or M CSCs based on clinical trials are summarized for further investigation. Since future research needs to adopt suitable tumor models and take into account the divergence of E and M CSCs for the development of effective treatments, TNBC models for clinically translatable studies are further discussed.

The Emerging Role of YAP/TAZ in Tumor Immunity

Yes-associated protein (YAP)/WW domain-containing transcription regulator 1 (TAZ) is an important transcriptional regulator and effector of the Hippo signaling pathway that has emerged as a critical determinant of malignancy in many human tumors. YAP/TAZ expression regulates the cross-talk between immune cells and tumor cells in the tumor microenvironment through its influence on T cells, myeloid-derived suppressor cells, and macrophages. However, the mechanisms underlying these effects are poorly understood. An improved understanding of the role of YAP/TAZ in tumor immunity is essential for exploring innovative tumor treatments and making further breakthroughs in antitumor immunotherapy. This review primarily focuses on the role of YAP/TAZ in immune cells, their interactions with tumor cells, and how this impacts on tumorigenesis, progression, and therapy resistance.

Role of mTORC1 in intestinal epithelial repair and tumorigenesis

mTORC1 signaling is the prototypical pathway regulating protein synthesis and cell proliferation. mTORC1 is active in stem cells located at the base of intestinal crypts but silenced as transit-amplifying cells differentiate into enterocytes or secretory cells along the epithelium. After an insult or injury, self-limiting and controlled activation of mTORC1 is critical for the renewal and repair of intestinal epithelium. mTORC1 promotes epithelial cell renewal by driving cryptic stem cell division, and epithelial cell repair by supporting the dedifferentiation and proliferation of enterocytes or secretory cells. Under repeated insult or injury, mTORC1 becomes constitutively active, triggering an irreversible return to stemness, cell division, proliferation, and inflammation among dedifferentiated epithelial cells. Epithelium-derived cytokines promulgate inflammation within the lamina propria, which in turn releases inflammatory factors that act back on the epithelium where undamaged intestinal epithelial cells participate in the pervading state of inflammation and become susceptible to tumorigenesis.

LATS1/2 suppress NFκB and aberrant EMT initiation to permit pancreatic progenitor differentiation

The Hippo pathway directs cell differentiation during organogenesis, in part by restricting proliferation. How Hippo signaling maintains a proliferation-differentiation balance in developing tissues via distinct molecular targets is only beginning to be understood. Our study makes the unexpected finding that Hippo suppresses nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) signaling in pancreatic progenitors to permit cell differentiation and epithelial morphogenesis. We find that pancreas-specific deletion of the large tumor suppressor kinases 1 and 2 (Lats1/2PanKO) from mouse progenitor epithelia results in failure to differentiate key pancreatic lineages: acinar, ductal, and endocrine. We carried out an unbiased transcriptome analysis to query differentiation defects in Lats1/2PanKO. This analysis revealed increased expression of NFκB activators, including the pantetheinase vanin1 (Vnn1). Using in vivo and ex vivo studies, we show that VNN1 activates a detrimental cascade of processes in Lats1/2PanKO epithelium, including (1) NFκB activation and (2) aberrant initiation of epithelial-mesenchymal transition (EMT), which together disrupt normal differentiation. We show that exogenous stimulation of VNN1 or NFκB can trigger this cascade in wild-type (WT) pancreatic progenitors. These findings reveal an unexpected requirement for active suppression of NFκB by LATS1/2 during pancreas development, which restrains a cell-autonomous deleterious transcriptional program and thereby allows epithelial differentiation.

REGγ ablation impedes dedifferentiation of anaplastic thyroid carcinoma and accentuates radio-therapeutic response by regulating the Smad7-TGF-β pathway

Anaplastic thyroid cancer (ATC) is the most aggressive human thyroid malignancy, characterized by dedifferentiation and resistance to radioiodine therapy. The underlying mechanisms regulating ATC dedifferentiation are largely unknown. Here, we show that REGγ, a noncanonical proteasome activator highly expressed in ATC, is an important regulator of differentiation in ATC cells. Ablation of REGγ significantly restored expression of thyroid-specific genes, enhanced iodine uptake, and improved the efficacy of ¹³¹I therapy in ATC xenograft models. Mechanistically, REGγ directly binds to the TGF-β signaling antagonist Smad7 and promotes its degradation, leading to the activation of the TGF-β signal pathway. With gain- and loss-of-function studies, we demonstrate that Smad7 is an important mediator for the REGγ function in ATC cell dedifferentiation, which is supported by expression profiles in human ATC tissues. It seems that REGγ impinges on repression of thyroid-specific genes and promotion of tumor malignancy in ATC cells by activating the TGF-β signal pathway via degradation of Smad7. Thus, REGγ may serve as a novel therapeutic target for allowing radioiodine therapy in anaplastic thyroid cancer patients with poor prognosis.

ZNF280A Promotes Proliferation and Tumorigenicity via Inactivating the Hippo-Signaling Pathway in Colorectal Cancer

Aberrant expression of zinc-finger proteins has been extensively reported to contribute to malignant progression in a variety of cancers. However, clinical significance and biological roles of ZNF280A in the field of cancer are poorly known. In this study, the expression of ZNF280A was detected in clinical colorectal cancer (CRC) tissues. Functional experiments in vitro and animal experiment in vivo were performed to measure the effect of ZNF280A on the proliferation and tumorigenesis in CRC cells. Western blot and luciferase assays were used to identify the underlying pathway mediating the biological roles of ZNF280A in CRC. Here we report that ZNF280A was upregulated in CRC tissues and cells and a high expression of ZNF280A correlated with tumor, lymph node, and metastasis (TNM) classifications, clinical stage, and predicted poor prognosis and disease progression in CRC patients. Moreover, silencing ZNF280A repressed proliferation and induced G0 and/or G1 arrest in vitro, and it inhibited tumorigenesis of CRC cells in vivo. Our results further demonstrate that silencing ZNF280A inhibited the proliferation of CRC cells by activating Hippo signaling. Therefore, our results uncover a novel mechanistic understanding of ZNF280A-mediated tumor progression in CRC, and meanwhile they provide a novel prognostic factor in CRC patients and a potential therapeutic target for the treatment of CRC.

Yes-Associated Protein 1 as a Novel Prognostic Biomarker for Gastrointestinal Cancer: A Meta-Analysis

Background

Yes-associated protein 1 (YAP1) is an effector of Hippo pathway, which plays a significant role in cell proliferation and tumor progression. The relationship between YAP1 and gastrointestinal cancer has been explored in many previous studies. We conducted a meta-analysis to explore the prognostic effect of YAP1 in patients with gastrointestinal cancer.

Methods

A systematic search was performed through the PubMed, Web of Science, Embase, and Cochrane library databases to collect eligible studies. The pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were used to evaluate the relationship between YAP1 expression and gastrointestinal cancer clinical outcomes.

Results

A total of 2941 patients from 18 studies were enrolled. The results showed that elevated YAP1 expression predicted a poor prognosis in gastrointestinal cancer (HR = 1.56; 95% CI: 1.29-1.89; P < 0.001). Subgroup analyses indicated significant association between YAP1 overexpression and shorter OS of patients with esophageal squamous cell carcinoma (HR = 1.85; 95% CI: 1.25-2.73; P = 0.002), gastric cancer (HR = 1.41,95% CI: 1.02-1.95; P = 0.037), and colorectal cancer (pooled HR = 1.75; 95% CI: 1.42-2.15; P < 0.001). However, YAP1 expression did not affect DFS of patients with gastrointestinal cancer (pooled HR = 1.33; 95% CI: 0.95-1.88; P = 0.101).

Conclusion

Elevated YAP1 expression in patients with gastrointestinal cancer might be related to shorter OS. YAP1 protein could serve as a potential predictor of poor prognosis in gastrointestinal cancer.

Pectin Oligosaccharides Ameliorate Colon Cancer by Regulating Oxidative Stress- and Inflammation-Activated Signaling Pathways

Colon cancer (CC) is the third common neoplasm worldwide, and it is still a big challenge for exploring new effective medicine for treating CC. Natural product promoting human health has become a hot topic and attracted many researchers recently. Pectin, a complex polysaccharide in plant cell wall, mainly consists of four major types of polysaccharides: homogalacturonan, xylogalacturonan, rhamnogalacturonan I and II, all of which can be degraded into various pectin oligosaccharides (POS) and may provide abundant resource for exploring potential anticancer drugs. POS have been regarded as a novel class of potential functional food with multiple health-promoting properties. POS have antibacterial activities against some aggressive and recurrent bacterial infection and exert beneficial immunomodulation for controlling CC risk. However, the molecular functional role of POS in the prevention of CC risk and progression remains doubtful. The review focuses on antioxidant and anti-inflammatory roles of POS for promoting human health by regulating some potential oxidative and inflammation-activated pathways, such as ATP-activated protein kinase (AMPK), nuclear factor erythroid-2-related factor-2 (Nrf2), and nuclear factor-κB (NF-κB) pathways. The activation of these signaling pathways increases the antioxidant and antiinflammatory activities, which will result in the apoptosis of CC cells or in the prevention of CC risk and progression. Thus, POS may inhibit CC development by affecting antioxidant and antiinflammatory signaling pathways AMPK, Nrf2, and NF-κB. However, POS also can activate signal transduction and transcriptional activator 1 and 3 signaling pathway, which will reduce antioxidant and anti-inflammatory properties and promote CC progression. Specific structural and structurally modified POS may be associated with their functions and should be deeply explored in the future. The present review paper lacks the important information for the linkage between the specific structure of POS and its function. To further explore the effects of prebiotic potential of POS and their derivatives on human immunomodulation in the prevention of CC, the specific POS with a certain degree of polymerization or purified polymers are highly demanded to be performed in clinical practice.