Cytoplasmic LIF reprograms invasive mode to enhance NPC dissemination through modulating YAP1-FAK/PXN signaling

Mechanical network motifs as targets for mechanomedicine

The identification and analysis of network motifs has been widely used in the functional analysis of signaling components, disease discovery and other fields. The positive feedback loop (PFL) is a simple but important network motif. The formation of a PFL is regulated by mechanical cues such as substrate stiffness, fiber stretching and cell compression in the cell microenvironment. Here, we propose a new term, 'mechanical PFL', and analyze the mechanisms of mechanical PFLs at molecular, subcellular and cellular scales. More and more therapies are being targeted against mechanosignaling pathways at the experimental and preclinical stages, and exploring mechanical PFLs as potential mechanomedicine targets could be a new direction for disease treatment.

Ginsenoside Rh1, a novel casein kinase II subunit alpha (CK2α) inhibitor, retards metastasis via disrupting HHEX/CCL20 signaling cascade involved in tumor cell extravasation across endothelial barrier

Tumor cell extravasation across endothelial barrier has been recognized as a pivotal event in orchestrating metastasis formation. This event is initiated by the interactions of extravasating tumor cells with endothelial cells (ECs). Therefore, targeting the crosstalk between tumor cells and ECs might be a promising therapeutic strategy to prevent metastasis. In this study, we demonstrated that Rh1, one of the main ingredients of ginseng, hindered the invasion of breast cancer (BC) cells as well as diminished the permeability of ECs both in vitro and in vivo, which was responsible for the attenuated tumor cell extravasation across endothelium. Noteworthily, we showed that ECs were capable of inducing the epithelial-mesenchymal transition (EMT) and invadopodia of BC cells that are essential for tumor cell migration and invasion through limiting the nuclear translocation of hematopoietically expressed homeobox (HHEX). The decreased nuclear HHEX paved the way for initiating the CCL20/CCR6 signaling axis, which in turn contributed to damaged endothelial junctions, uncovering a new crosstalk mode between tumor cells and ECs. Intriguingly, Rh1 inhibited the kinase activity of casein kinase II subunit alpha (CK2α) and further promoted the nuclear translocation of HHEX in the BC cells, which resulted in the disrupted crosstalk between chemokine (C-C motif) ligand 20 (CCL20) in the BC cells and chemokine (C-C motif) receptor 6 (CCR6) in the ECs. The prohibited CCL20-CCR6 axis by Rh1 enhanced vascular integrity and diminished tumor cell motility. Taken together, our data suggest that Rh1 serves as an effective natural CK2α inhibitor that can be further optimized to be a therapeutic agent for reducing tumor cell extravasation.

A 3-gene signature comprising CDH4, STAT4 and EBV-encoded LMP1 for early diagnosis and predicting disease progression of nasopharyngeal carcinoma

PURPOSE

Nasopharyngeal carcinoma is highly metastatic but difficult to detect in its early stages. It is critical to develop a simple and highly efficient molecular diagnostic method for early detection of NPC in clinical biopsies.

METHODS

The transcriptomic data of primary NPC cell strains were used as a discovery tool. Linear regression approach was used to define signatures distinctive between early and late stage of NPC. Expressions of candidates were validated with an independent set of biopsies (n = 39). Leave-one-out cross-validation technique was employed to estimate the prediction accuracy on stage classification. The clinical relevance of marker genes was verified using NPC bulk RNA sequencing data and IHC analysis.

RESULTS

Three genes comprising CDH4, STAT4, and CYLD were found to have a significant differentiating power to separate NPC from normal nasopharyngeal samples and predicting disease malignancy. IHC analyses showed stronger CDH4, STAT4, and CYLD immunoreactivity in adjacent basal epithelium compared with that in tumor cells (p < 0.001). EBV-encoded LMP1 was exclusively expressed in NPC tumors. Using an independent set of biopsies, we showed that a model combining CDH4, STAT4, and LMP1 had a 92.86% of diagnostic accuracy, whereas a combination of STAT4 and LMP1 had a 70.59% accuracy for predicting advanced disease. Mechanistic studies suggested that promoter methylation, loss of DNA allele, and LMP1 contributed to the suppressive expression of CDH4, CYLD, and STAT4, respectively.

CONCLUSION

A model combining CDH4 and STAT4 and LMP1 was proposed to be a feasible model for diagnosing NPC and predicting late stage of NPC.

Targeting Leukemia Inhibitory Factor in Pancreatic Adenocarcinoma

INTRODUCTION

Leukemia Inhibitory Factor (LIF) is a member of the interleukin-6 (IL-6) cytokine family. Known to induce differentiation of myeloid leukemia cells, evidence has accumulated supporting its role in cancer evolution though regulating cell differentiation, renewal, and survival. LIF has recently emerged as a biomarker and therapeutic target for pancreatic ductal adenocarcinoma (PDAC). The first-in-human clinical trial has shown promising safety profile and has suggested a potential role for LIF inhibitor in combination regimen.

AREAS COVERED

Herein, we summarize, discuss, and give an expert opinion on the role of LIF in PDAC promotion, and its potential role as a biomarker and target of anti-cancer therapy. We conducted an exhaustive PubMed search for English-language articles published from January 1, 1970, to August 1, 2022.

EXPERT OPINION

PDAC carries a devastating prognosis for patients, highlighting the need for advancing drug development. The results of the phase 1 trial with MSC-1 demonstrated tolerability and safety but modest efficacy. Future research should focus on investigating LIF targets in combination with current standard-of-care chemotherapy and immunotherapy can be a promising approach. Further, larger multicenter clinical trials are needed to define the use of LIF as a new biomarker in PDAC patients.

MicroRNA-145-5p modulates Krüppel-like factor 5 and inhibits cell proliferation, migration, and invasion in nasopharyngeal carcinoma

Background

In several human cancers, Krüppel-like factor 5 (KLF5), a zinc finger transcription factor, can contribute to both tumor progression or suppression; however, the precise role of KLF5 in nasopharyngeal carcinoma (NPC) remains poorly understood. In this study, the association between KLF5 and microRNA-145-5p (miR-145-5p) in NPC cells was elucidated.

Results

Our results showed that KLF5 expression was up-regulated in NPC group compared to normal group. We found that KLF5 exhibited an oncogenic role in NPC cells. The upregulation of miR-145-5p inhibited the proliferation, migration, and invasion of NPC cells. It was observed that miR-145-5p could down-regulate the mRNA and protein expression of KLF5 in NPC cell lines. Additionally, the activity of focal adhesion kinase (FAK), a migration marker, was regulated by miR-145-5p and KLF5 in NPC cells.

Conclusions

The results of this study indicated that miR-145-5p could repress the proliferation, migration, and invasion of NPC cells via KLF5/FAK regulation, and could be a potential therapeutic target for patients with NPC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12860-022-00430-9.

The inhibition of centromere protein K causes anticancer effects in breast carcinoma via effects on the FAK/PI3K/AKT/mTOR pathway

The overexpression of centromere protein K (CENPK) is a major contributor to the malignant progression of numerous cancers. To date, the detailed functions and mechanisms of CENPK in breast carcinoma are not fully elucidated. The goals of this project were to comprehensively address the relevance of CENPK in breast carcinoma. The initial investigation by TCGA analysis revealed a high expression level of CENPK in breast carcinoma. Subsequently, an immunoblotting assay confirmed that CENPK is highly expressed in the clinical samples of breast carcinoma. In vitro experiments elucidated that the inhibition of CENPK produced substantial anticancer effects, including a reduction of proliferation, the inhibition of epithelial-mesenchymal transition, the induction of cell cycle arrest and chemosensitivity. Mechanism research unveiled a role for CENPK in mediating the focal adhesion kinase (FAK1)/PI3K/AKT/mTOR pathway. Inhibiting the FAK/PI3K/AKT/mTOR pathway was able to reverse CENPK-elicited cancer-promoting effects. Additionally, CENPK-silenced breast carcinoma cells exhibited low tumorigenicity in vivo. In summary, our data demonstrated that CENPK inhibition provided an excellent anticancer effect for breast carcinoma by regulating FAK/PI3K/AKT/mTOR pathway. This work illustrates a novel molecular mechanism for CENPK in breast carcinoma and suggests CENPK inhibition as a promising targeted therapy for breast carcinoma.

ROBO3s: a novel ROBO3 short isoform promoting breast cancer aggressiveness

Basal-like breast cancer (BLBC) is a highly aggressive breast cancer subtype frequently associated with poor prognosis. Due to the scarcity of targeted treatment options, conventional cytotoxic chemotherapies frequently remain the standard of care. Unfortunately, their efficacy is limited as BLBC malignancies rapidly develop resistant phenotypes. Using transcriptomic and proteomic approaches in human and murine BLBC cells, we aimed to elucidate the molecular mechanisms underlying the acquisition of aggressive and chemotherapy-resistant phenotypes in these mammary tumors. Specifically, we identified and characterized a novel short isoform of Roundabout Guidance Receptor 3 (ROBO3s), upregulated in BLBC in response to chemotherapy and encoding for a protein variant lacking the transmembrane domain. We established an important role for the ROBO3s isoform, mediating cancer stem cell properties by stimulating the Hippo-YAP signaling pathway, and thus driving resistance of BLBC cells to cytotoxic drugs. By uncovering the conservation of ROBO3s expression across multiple cancer types, as well as its association with reduced BLBC-patient survival, we emphasize its potential as a prognostic marker and identify a novel attractive target for anti-cancer drug development.

Treatment of Recurrent Nasopharyngeal Carcinoma: A Sequential Challenge

Simple Summary

Recurrent nasopharyngeal carcinoma is one of the major causes of death among NPC patients. However, there are no international guidelines for the treatment of patients with recurrent NPC now. In this article, we summarize past publications on clinical research and mechanistic studies related to recurrent NPC, combined with the experience and lessons learned by our institutional multidisciplinary team in the treatment of recurrent NPC. We propose an objective protocol for the treatment of recurrent NPC.

Abstract

Recurrent nasopharyngeal carcinoma (NPC), which occurs in 10–20% of patients with primary NPC after the initial treatment modality of intensity-modulated radiation therapy (IMRT), is one of the major causes of death among NPC patients. Patients with recurrent disease without distant metastases still have a chance to be saved, but re-treatment often carries more serious toxicities or higher risks. For this group of patients, both otolaryngologists and oncologists are committed to developing more appropriate treatment regimens that can prolong patient survival and improve survival therapy. Currently, there are no international guidelines for the treatment of patients with recurrent NPC. In this article, we summarize past publications on clinical research and mechanistic studies related to recurrent NPC, combined with the experience and lessons learned by our institutional multidisciplinary team in the treatment of recurrent NPC. We propose an objective protocol for the treatment of recurrent NPC.

Epstein-Barr viral product-containing exosomes promote fibrosis and nasopharyngeal carcinoma progression through activation of YAP1/FAPα signaling in fibroblasts

Background

The progression of nasopharyngeal carcinoma (NPC) is profoundly affected by Epstein-Barr virus (EBV) infection. However, the role of EBV in the intercommunication between NPC and surrounding stromal cells has yet to be explored.

Methods

NPC biopsies were obtained for immunohistochemical (IHC) analyses. Clinical correlations between the expression of active YAP1/FAPα and the fibrotic response and between YAP1/FAPα and the density of cytotoxic CD8a+ T lymphocytes were determined. Survival times based on IHC scores were compared between groups using Kaplan-Meier survival and log-rank tests. Independent prognostic factors for metastasis/recurrence-free survival and overall survival were identified using univariate and multivariate Cox regression models. Fibroblasts were isolated from human nasopharyngeal biopsies. Exosomes were purified from culture supernatants of EBV+-positive NPC cells. The effects of EBV product-containing exosomes on fibroblast activation, fibrotic response, tumor growth, immune response, and correlations between the expression of featured genes were investigated using gel contraction assays, ELISAs, EdU incorporation assays, real-time impedance assays, RNA sequencing, immunostaining, 3D cancer spheroid coculture systems, and an NPC xenograft model.

Results

NPC patients who developed metastasis had significantly higher levels of active YAP1 and FAPα in their tumor stroma, which was further correlated with tumor fibrosis and poorer metastasis-free survival. Exosomes released from EBV+-NPC cells contained abundant FAPα protein and EBV-encoded latent membrane protein 1. Viral product-containing exosomes markedly enhanced the fibrotic response and tumor growth in a mouse xenograft model. IHC analyses of human NPC and NPC xenografts revealed positive correlations between levels of active YAP1 and FAPα, YAP1 and the fibrotic response, and FAPα and the fibrotic response. Mechanistic studies showed that treatment of fibroblasts with viral product-containing exosomes promoted the characteristics of cancer-associated fibroblasts by stimulating YAP1 signaling and the production of the immunosuppressive cytokines IL8, CCL2, and IL6. Inhibition of YAP1 activation markedly reversed these exosome-mediated protumoral effects, resulting in reduced contractility, inactivation of YAP1 signaling, and decreased production of immunosuppressive cytokines in fibroblasts. Furthermore, fibroblasts stimulated with these viral product-containing exosomes promoted NPC resistance to T cell-mediated cytotoxicity within tumor spheroids. In NPC tissues, a significant negative correlation was found between YAP1/FAPα and the density of CD8a+ T lymphocytes with a granzyme B signature.

Conclusion

EBV orchestrates interactions with the host and surrounding stroma by stimulating the functions of YAP1 and FAPα in fibroblasts through exosome cargos to create a more immunosuppressive, proinvasive microenvironment.

The Pleiotropic role, functions and targeted therapies of LIF/LIFR axis in cancer: Old spectacles with new insights

The dysregulation of leukemia inhibitory factor (LIF) and its cognate receptor (LIFR) has been associated with multiple cancer initiation, progression, and metastasis. LIF plays a significant tumor-promoting role in cancer, while LIFR functions as a tumor promoter and suppressor. Epithelial and stromal cells secrete LIF via autocrine and paracrine signaling mechanism(s) that bind with LIFR and subsequently with co-receptor glycoprotein 130 (gp130) to activate JAK/STAT1/3, PI3K/AKT, mTORC1/p70s6K, Hippo/YAP, and MAPK signaling pathways. Clinically, activating the LIF/LIFR axis is associated with poor survival and anti-cancer therapy resistance. This review article provides an overview of the structure and ligands of LIFR, LIF/LIFR signaling in developmental biology, stem cells, cancer stem cells, genetics and epigenetics of LIFR, LIFR regulation by long non-coding RNAs and miRNAs, and LIF/LIFR signaling in cancers. Finally, neutralizing antibodies and small molecule inhibitors preferentially blocking LIF interaction with LIFR and antagonists against LIFR under pre-clinical and early-phase pre-clinical trials were discussed.

Epithelial–mesenchymal transition: The history, regulatory mechanism, and cancer therapeutic opportunities

Epithelial–mesenchymal transition (EMT) is a program wherein epithelial cells lose their junctions and polarity while acquiring mesenchymal properties and invasive ability. Originally defined as an embryogenesis event, EMT has been recognized as a crucial process in tumor progression. During EMT, cell–cell junctions and cell–matrix attachments are disrupted, and the cytoskeleton is remodeled to enhance mobility of cells. This transition of phenotype is largely driven by a group of key transcription factors, typically Snail, Twist, and ZEB, through epigenetic repression of epithelial markers, transcriptional activation of matrix metalloproteinases, and reorganization of cytoskeleton. Mechanistically, EMT is orchestrated by multiple pathways, especially those involved in embryogenesis such as TGFβ, Wnt, Hedgehog, and Hippo, suggesting EMT as an intrinsic link between embryonic development and cancer progression. In addition, redox signaling has also emerged as critical EMT modulator. EMT confers cancer cells with increased metastatic potential and drug resistant capacity, which accounts for tumor recurrence in most clinic cases. Thus, targeting EMT can be a therapeutic option providing a chance of cure for cancer patients. Here, we introduce a brief history of EMT and summarize recent advances in understanding EMT mechanisms, as well as highlighting the therapeutic opportunities by targeting EMT in cancer treatment.

Epithelial LIF signaling limits apoptosis and lung injury during bacterial pneumonia

During bacterial pneumonia, alveolar epithelial cells are critical for maintaining gas exchange and providing antimicrobial as well as pro-immune properties. We previously demonstrated that leukemia inhibitory factor (LIF), an IL-6 family cytokine, is produced by type II alveolar epithelial cells (ATII) and is critical for tissue protection during bacterial pneumonia. However, the target cells and mechanisms of LIF-mediated protection remain unknown. Here, we demonstrate that antibody-induced LIF blockade remodels the lung epithelial transcriptome in association with increased apoptosis. Based on these data, we performed pneumonia studies using a novel mouse model in which LIFR (the unique receptor for LIF) is absent in lung epithelium. Although LIFR is expressed on the surface of epithelial cells, its absence only minimally contributed to tissue protection during pneumonia. Single-cell RNA-sequencing (scRNAseq) was conducted to identify adult murine lung cell types most prominently expressing Lifr, revealing endothelial cells, mesenchymal cells, and ATIIs as major sources of Lifr. Sequencing data indicated that ATII cells were significantly impacted by pneumonia, with additional differences observed in response to LIF neutralization, including but not limited to gene programs related to cell death, injury, and inflammation. Overall, our data suggest that LIF signaling on epithelial cells alters responses in this cell type during pneumonia. However, our results also suggest separate and perhaps more prominent roles of LIFR in other cell types, such as endothelial cells or mesenchymal cells, which provide grounds for future investigation.

Leukemia Inhibitory Factor: An Important Cytokine in Pathologies and Cancer

Leukemia Inhibitory Factor (LIF) is a member of the IL-6 cytokine family and is expressed in almost every tissue type within the body. Although LIF was named for its ability to induce differentiation of myeloid leukemia cells, studies of LIF in additional diseases and solid tumor types have shown that it has the potential to contribute to many other pathologies. Exploring the roles of LIF in normal physiology and non-cancer pathologies can give important insights into how it may be dysregulated within cancers, and the possible effects of this dysregulation. Within various cancer types, LIF expression has been linked to hallmarks of cancer, such as proliferation, metastasis, and chemoresistance, as well as overall patient survival. The mechanisms behind these effects of LIF are not well understood and can differ between different tissue types. In fact, research has shown that while LIF may promote malignancy progression in some solid tumors, it can have anti-neoplastic effects in others. This review will summarize current knowledge of how LIF expression impacts cellular function and dysfunction to help reveal new adjuvant treatment options for cancer patients, while also revealing potential adverse effects of treatments targeting LIF signaling.

The Role of the IL-6 Cytokine Family in Epithelial-Mesenchymal Plasticity in Cancer Progression

Epithelial–mesenchymal plasticity (EMP) plays critical roles during embryonic development, wound repair, fibrosis, inflammation and cancer. During cancer progression, EMP results in heterogeneous and dynamic populations of cells with mixed epithelial and mesenchymal characteristics, which are required for local invasion and metastatic dissemination. Cancer development is associated with an inflammatory microenvironment characterized by the accumulation of multiple immune cells and pro-inflammatory mediators, such as cytokines and chemokines. Cytokines from the interleukin 6 (IL-6) family play fundamental roles in mediating tumour-promoting inflammation within the tumour microenvironment, and have been associated with chronic inflammation, autoimmunity, infectious diseases and cancer, where some members often act as diagnostic or prognostic biomarkers. All IL-6 family members signal through the Janus kinase (JAK)–signal transducer and activator of transcription (STAT) pathway and are able to activate a wide array of signalling pathways and transcription factors. In general, IL-6 cytokines activate EMP processes, fostering the acquisition of mesenchymal features in cancer cells. However, this effect may be highly context dependent. This review will summarise all the relevant literature related to all members of the IL-6 family and EMP, although it is mainly focused on IL-6 and oncostatin M (OSM), the family members that have been more extensively studied.

Emerging Perspectives on Leukemia Inhibitory Factor and its Receptor in Cancer

Tumorigenesis and metastasis have deep connections to inflammation and inflammatory cytokines, but the mechanisms underlying these relationships are poorly understood. Leukemia Inhibitory Factor (LIF) and its receptor (LIFR), part of the interleukin-6 (IL-6) cytokine family, make up one such ill-defined piece of the puzzle connecting inflammation to cancer. Although other members of the IL-6 family have been shown to be involved in the metastasis of multiple types of cancer, the role of LIF and LIFR has been challenging to determine. Described by others in the past as enigmatic and paradoxical, LIF and LIFR are expressed in a diverse array of cells in the body, and the narrative surrounding them in cancer-related processes has been vague, and at times even contradictory. Despite this, recent insights into their functional roles in cancer have highlighted interesting patterns that may allude to a broader understanding of LIF and LIFR within tumor growth and metastasis. This review will discuss in depth the signaling pathways activated by LIF and LIFR specifically in the context of cancer-the purpose being to summarize recent literature concerning the downstream effects of LIF/LIFR signaling in a variety of cancer-related circumstances in an effort to begin teasing out the intricate web of contradictions that have made this pair so challenging to define.

The emerging role of leukemia inhibitory factor in cancer and therapy

Leukemia inhibitory factor (LIF) is a multi-functional cytokine of the interleukin-6 (IL-6) superfamily. Initially identified as a factor that inhibits the proliferation of murine myeloid leukemia cells, LIF displays a wide variety of important functions in a cell-, tissue- and context-dependent manner in many physiological and pathological processes, including regulating cell proliferation, pluripotent stem cell self-renewal, tissue/organ development and regeneration, neurogenesis and neural regeneration, maternal reproduction, inflammation, infection, immune response, and metabolism. Emerging evidence has shown that LIF plays an important but complex role in human cancers; while LIF displays a tumor suppressive function in some types of cancers, including leukemia, LIF is overexpressed and exerts an oncogenic function in many more types of cancers. Further, targeting LIF has been actively investigated as a novel strategy for cancer therapy. This review summarizes the recent advances in the studies on LIF in human cancers and its potential application in cancer therapy. A better understanding of the role of LIF in different types of cancers and its underlying mechanisms will help to develop more effective strategies for cancer therapy.

Epstein-Barr Virus Induces Adipocyte Dedifferentiation to Modulate the Tumor Microenvironment

The most frequent location of metastatic EBV+ nasopharyngeal carcinoma (NPC) is the bone marrow, an adipocyte-dominant region. Several EBV-associated lymphoepithelioma-like carcinoma (LELC) types also grow in the anatomical vicinity of fat tissues. Here we show that in an adipose tissue-rich tumor setting, EBV targets adipocytes and remodels the tumor microenvironment. Positive immunoreactivity for EBV-encoded early antigen D was detected in adipose tissue near tumor beds of bone marrow metastatic NPC. EBV was capable of infecting primary human adipocytes in vitro, triggering expression of multiple EBV-encoded mRNA and proteins. In infected adipocytes, lipolysis was stimulated through enhanced expression of lipases and the AMPK metabolic pathway. The EBV-mediated imbalance in energy homeostasis was further confirmed by increased release of free fatty acids, glycerol, and expression of proinflammatory adipokines. Clinically, enhanced serum levels of free fatty acids in patients with NPC correlated with poorer recurrence-free survival. EBV-induced delipidation stimulated dedifferentiation of adipocytes into fibroblast-like cells expressing higher levels of S100A4, a marker protein of cancer-associated fibroblasts (CAF). IHC analyses of bone marrow metastatic NPC and salivary LELC revealed similar structural changes of dedifferentiated adipocytes located at the boundaries of EBV+ tumors. S100A4 expression in adipose tissues near tumor beds correlated with fibrotic response, implying that CAFs in the tumor microenvironment are partially derived from EBV-induced dedifferentiated adipocytes. Our data suggest that adipose tissue serves as an EBV reservoir, where EBV orchestrates the interactions between adipose tissues and tumor cells by rearranging metabolic pathways to benefit virus persistence and to promote a protumorigenic microenvironment. SIGNIFICANCE: This study suggests that Epstein-Barr virus hijacks adipocyte lipid metabolism to create a tumor-promoting microenvironment from which reactivation and relapse of infection could potentially occur.

Chrysin serves as a novel inhibitor of DGKα/FAK interaction to suppress the malignancy of esophageal squamous cell carcinoma (ESCC)

Among current novel druggable targets, protein–protein interactions (PPIs) are of considerable and growing interest. Diacylglycerol kinase α (DGKα) interacts with focal adhesion kinase (FAK) band 4.1-ezrin-radixin-moesin (FERM) domain to induce the phosphorylation of FAK Tyr397 site and promotes the malignant progression of esophageal squamous cell carcinoma (ESCC) cells. Chrysin is a multi-functional bioactive flavonoid, and possesses potential anticancer activity, whereas little is known about the anticancer activity and exact molecular mechanisms of chrysin in ESCC treatment. In this study, we found that chrysin significantly disrupted the DGKα/FAK signalosome to inhibit FAK-controlled signaling pathways and the malignant progression of ESCC cells both in vitro and in vivo, whereas produced no toxicity to the normal cells. Molecular validation specifically demonstrated that Asp435 site in the catalytic domain of DGKα contributed to chrysin-mediated inhibition of the assembly of DGKα/FAK complex. This study has illustrated DGKα/FAK complex as a target of chrysin for the first time, and provided a direction for the development of natural products-derived PPIs inhibitors in tumor treatment.

Plasticity of cancer cell invasion: Patterns and mechanisms

Cancer cell migration and invasion are integral components of metastatic disease, which is the major cause of death in cancer patients. Cancer cells can disseminate and migrate via several alternative mechanisms including amoeboid cell migration, mesenchymal cell migration, and collective cell migration. These diverse movement strategies display certain specific and distinct hallmarks in cell-cell junctions, actin cytoskeleton, matrix adhesion, and protease activity. During tumor progression, cells pass through complex microenvironments and adapt their migration strategies by reversible mesenchymal-amoeboid and individual-collective transitions. This plasticity in motility patterns enables cancer cells disseminate further and thus limit the efficiency of anti-metastasis therapies. In this review, we discuss the modes and mechanisms of cancer cell migration and focus on the plasticity of tumor cell movement as well as potential emerging therapeutic options for reducing cancer cell invasion.

Role of Focal Adhesion Kinase in Head and Neck Squamous Cell Carcinoma and Its Therapeutic Prospect

Head and neck cancers are one of the most prevalent cancers globally. Among them, head and neck squamous cell carcinoma (HNSCC) accounts for approximately 90% of head and neck cancers, which occurs in the oral cavity, oral pharynx, hypopharynx and larynx. The 5-year survival rate of HNSCC patients is only 63%, mainly because about 80–90% of patients with advanced HNSCC tend to suffer from local recurrence or even distant metastasis. Despite the more in-depth understanding of the molecular mechanisms underlying the occurrence and progression of HNSCC in recent years, effective targeted therapies are unavailable for HNSCC, which emphasize the urgent demand for studies in this area. Focal adhesion kinase (FAK) is an intracellular non-receptor tyrosine kinase that contributes to oncogenesis and tumor progression by its significant function in cell survival, proliferation, adhesion, invasion and migration. In addition, FAK exerts an effect on the tumor microenvironment, epithelial–mesenchymal transition, radiation (chemotherapy) resistance, tumor stem cells and regulation of inflammatory factors. Moreover, the overexpression and activation of FAK are detected in multiple types of tumors, including HNSCC. FAK inhibition can induce cell cycle arrest and apoptosis, significantly decrease cell growth, invasion and migration in HNSCC cell lines. In this article, we mainly review the research progress of FAK in the occurrence, development and metastasis of HNSCC, and put forward the prospects for the therapeutic targets of HNSCC.

Leukemia inhibitory factor promotes gastric cancer cell proliferation, migration, and invasion via the LIFR-Hippo-YAP pathway

The long-term outcome of gastric cancer (GC) patients remains unsatisfactory despite some recent improvements. Leukemia inhibitory factor (LIF) is a prognostic biomarker for some solid tumors, however its role in GC remains unknown. In this study, we demonstrated that LIF and LIF receptor (LIFR) are overexpressed in GC tissues and established that a correlation exists between them. LIF and LIFR expression are associated with tumor differentiation, lymphovascular invasion, tumor stage, lymph node metastasis, and pTNM stage, indicating that they may be useful prognostic factors. LIF promoted GC cell proliferation, colony formation, invasion, migration, and tumor growth; it also promoted cell cycle progression and inhibited apoptosis; and knocking out the LIFR gene reversed the effects of LIF. LIF inhibited the activity of the Hippo pathway, resulting in reduced phosphorylation of YAP, increased YAP nuclear translocation, and increased cell proliferation. Finally, silencing YAP mRNA expression suppressed cell proliferation. Overall, the results demonstrate that LIF promotes the malignant biological behavior of GC cells through LIFR-Hippo-YAP signaling. LIF may therefore be a useful biomarker for GC.

Emerging therapeutic targets for nasopharyngeal carcinoma: opportunities and challenges

Introduction: Nasopharyngeal carcinoma (NPC) is a major public health problem in several countries, especially those in Southeast Asia and North Africa. In its typical poorly differentiated form, the Epstein-Barr virus (EBV) genome is present in the nuclei of all malignant cells with restricted expression of a few viral genes. The malignant phenotype of NPC cells results from the influence of these viral products in combination with cellular genetic, epigenetic and functional alterations. With regard to host/tumor interactions, NPC is a remarkable example of immune escape in the context of a hot tumor.Areas covered: This article has an emphasis on emerging therapeutic targets that are considered upstream or at an early stage of clinical application. It examines targets related to cellular oncogenic alterations, latent EBV infection and tumor interactions with the immune system.Expert opinion: There is a remarkable emergence of new agents that target EBV products. The clinical application of these agents would benefit from a systematic and comprehensive molecular classification of NPCs and from easy access to pre-clinical models in public repositories. There is a strong rationale for more investigations on the potential of immune modulators, especially those related to NK cells.

Differential Expression and Alternative Splicing of Transcripts Associated With Cisplatin-Induced Chemoresistance in Nasopharyngeal Carcinoma

Radiotherapy and adjuvant cisplatin (DDP) chemotherapy are standard administrations applied to treat nasopharyngeal carcinoma (NPC). However, the molecular changes and functions of DDP in NPC chemo-resistance remain poorly understood. In the present study, transcriptomic sequencing between 5-8F and 5-8F/DDP cells was performed to identify differential expression and alternative splicing (AS) characteristics in DDP-resistant NPC cells. Transcriptomic profiling identified 1,757 upregulated genes and 1,473 downregulated differentially expressed genes (DEGs). Bioinformatic analysis revealed that these DEGs were associated with or participated in important biological regulatory functions in NPC. Validation of 20 significant DEGs using quantitative real-time reverse transcription PCR showed that the expression patterns of 17 mRNAs were in accordance with the sequencing data. Intron retention was identified as the major AS event in chemoresistant cells. Furthermore, the expression level of matrix metalloproteinase 1 (MMP1), which was one of the most upregulated mRNAs in the chemoresistant cell lines, was significantly associated with the migration, invasion, and proliferation of NPC cells in vitro. Our study revealed that dysregulated genes and AS-mediated DDP chemoresistance might play important roles in NPC development and progression. Targeting aberrantly expressed genes might clarify the pathogenesis of NPC and contribute to developing new therapeutic strategies for NPC.

[Overexpression of leukemia inhibitory factor enhances chemotherapy tolerance of endometrial cancer cells in vitro]

OBJECTIVE

To investigate the effect of overexpression of leukemia inhibitory factor (LIF) on cisplatin and paclitaxel resistance of endometrial cancer cells in vitro.

METHODS

Endometrial cancer cell lines HEC-1B and RL95-2 were infected with a recombinant lentivirus to overexpress LIF, and the changes in LIF expression was verified using RT-qPCR and ELISA. The viability of the LIF-overexpressing cells was assessed using CCK-8 assay, and the cell apoptosis and changes in mitochondrial membrane potential in response to cisplatin or paclitaxel treatment were analyzed with annexin V-FITC/PI staining and JC-1 assay, respectively. The effect of LIF overexpression on the expressions of Bcl-2 family proteins and STAT3 pathway was evaluated using Western blotting; dual-luciferase reporter gene assay was employed to detect the transcriptional activity of STAT3. The effect of STAT3 silencing on apoptosis of the LIF-overexpressing cells induced by cisplatin or paclitaxel was investigated.

RESULTS

The cell lines infected with the recombinant lentivirus showed significantly increased mRNA and protein levels of LIF (P < 0.05) without obvious changes in the cell viability (P>0.05). LIF overexpression significantly attenuated cisplatin-or paclitaxel-induced apoptosis of the endometrial cancer cells (P < 0.05) and markedly increased mitochondrial membrane potential of the cells (P < 0.05). The expressions of Bcl-2, Bcl-xL and p-STAT3 proteins increased obviously while the expressions of Bax, Bad and STAT3 either decreased or showed no obvious changes in the LIF-overexpressing cells. Overexpressing LIF significantly enhanced the transcriptional activity of STAT3 (P < 0.05), and silencing STAT3 obviously enhanced apoptosis of the endometrial cancer cells overexpressing LIF (P < 0.05).

CONCLUSIONS

s Overexpression of LIF can enhance cisplatin and paclitaxel resistance to endometrial cancer cells in vitro.

Prognostic value of leukemia inhibitory factor and its receptor in pancreatic adenocarcinoma

Currently, the prognostic effects of leukemia inhibitory factor (LIF) and LIF receptor (LIFR) in pancreatic adenocarcinoma (PAAD) are not clear. In the present study, we utilized the large datasets from four public databases to investigate the expression of LIF and LIFR and their clinical significance in PAAD. Eight cohorts containing 1278 cases with PAAD were identified and the analysis results suggested that LIF was highly expressed while LIFR was lowly expressed in PAAD tissues compared with adjacent or normal tissues. Kaplan-Meier plot curves and univariate and multivariate Cox proportional hazards regression analyses indicated high LIF expression was associated with shorter overall survival (adjusted hazard ratio = 1.641, 95% CI: 1.399-1.925, p < 0.001) whereas high LIFR expression was associated with longer overall survival (adjusted hazard ratio = 0.653, 95% CI: 0.517-0.826, p < 0.001).

YAP Promotes VEGFA Expression and Tumor Angiogenesis Though Gli2 in Human Renal Cell Carcinoma

BACKGROUND

High vascularization is a major characteristic of renal cell carcinoma (RCC). Thus, exploration of molecules promoting the tumor vascularization in RCC is urgent. Yes-associated Protein (YAP) is an oncogene in many cancer types, and high YAP expression was correlated with worse overall survival of RCC patients according to The Cancer Genome Atlas (TCGA) database. However, whether YAP promotes tumor angiogenesis of RCC is still unknown.

METHODS

Western blotting assay, real-time Quantitive PCR analysis, and ELISA assay were used to detect the related gene expression. The function of YAP on tumor angiogenesis was investigated by HUVEC recruitment, tube formation, and rabbit cornea assay. The clinical relevance of several genes was analyzed in a public database.

RESULTS

knockdown of YAP decreased RCC cell-inducing HUVEC recruitment and tube formation. Moreover, tumor angiogenesis ability of 786-O cells was crippled by YAP knockdown in vivo. In addition, the expression of Vascular endothelial growth factors A (VEGFA) was positively correlated with YAP expression in RCC tumor tissues, and YAP promoted expression and secretion of VEGFA in RCC cells. Mechanistically, GLI family zinc finger 2 (Gli2) knockdown in RCC cells reduced both basic and YAP-induced VEGFA expression, HUVECs recruitment, and tube formation, indicating that Gli2 is necessary for YAP to promote expression of VEGFA.

CONCLUSION

Taken together, our results demonstrate that YAP/Gli2 promotes VEGFA expression and tumor angiogenesis in RCC cells, which could provide novel therapeutic targets in RCC treatment.

A new, easily generated mouse model of diabetic kidney fibrosis

Our understanding of diabetic kidney disease pathogenesis has been hampered by the lack of easily generated pre-clinical animal models that faithfully recapitulate critical features of human disease. While most standard animal models develop manifestations of early stage diabetic injury such as hyperfiltration and mesangial matrix expansion, only a select few develop key late stage features such as interstitial fibrosis and reduced glomerular filtration rate. An underlying theme in these late stage disease models has been the addition of renin-angiotensin system hyperactivation, an important contributor to human disease pathogenesis. Widespread use of these models has been limited, however, as they are either labour intensive to generate, or have been developed in the rat, preventing the use of the many powerful genetic tools developed for mice. Here we describe the Akita^+/− Ren^+/− mouse, a new, easily generated murine model of diabetic kidney disease that develops many features of late stage human injury, including not only hyperglycemia, hypertension, and albuminuria, but also reduced glomerular filtration rate, glomerulosclerosis, and interstitial fibrosis.