CCL20 mediates RANK/RANKL-induced epithelial-mesenchymal transition in endometrial cancer cells

RANKL/RANK signaling recruits Tregs via the CCL20-CCR6 pathway and promotes stemness and metastasis in colorectal cancer

TNF receptor superfamily member 11a (TNFRSF11a, RANK) and its ligand TNF superfamily member 11 (TNFRSF11, RANKL) are overexpressed in many malignancies. However, the clinical importance of RANKL/RANK in colorectal cancer (CRC) is mainly unknown. We examined CRC samples and found that RANKL/RANK was elevated in CRC tissues compared with nearby normal tissues. A higher RANKL/RANK expression was associated with a worse survival rate. Furthermore, RANKL was mostly produced by regulatory T cells (Tregs), which were able to promote CRC advancement. Overexpression of RANK or addition of RANKL significantly increased the stemness and migration of CRC cells. Furthermore, RANKL/RANK signaling stimulated C-C motif chemokine ligand 20 (CCL20) production by CRC cells, leading to Treg recruitment and boosting tumor stemness and malignant progression. This recruitment process was accomplished by CCL20-CCR6 interaction, demonstrating a connection between CRC cells and immune cells. These findings suggest an important role of RANKL/RANK in CRC progression, offering a potential target for CRC prevention and therapy.

Multi-omics analysis reveals mechanism of Schisandra chinensis lignans and acteoside on EMT in hepatoma cells via ERK1/2 pathway

BACKGROUND

Hepatocellular carcinoma (HCC), a globally common cancer, often presents late and shows high resistance to chemotherapy, resulting in suboptimal treatment efficacy. Components from traditional Chinese medicines have been recognized for their anti-cancer properties.

OBJECTIVE

Exploring the mechanism of Schisandra chinensis lignans and acteoside in suppressing Epithelial-Mesenchymal Transition (EMT) in hepatoma cells through the Extracellular signal-Regulated Kinases (ERK)1/2 pathway and identifying biomarkers, molecular subtypes, and targets via multi-omics for precision oncology.

METHODS

Proliferation was assessed using cell counting kit-8 (CCK-8) assays, with scratch and transwell assays for evaluating invasion and migration. Flow cytometry quantified apoptosis rates. Expression levels of CCL20, p-ERK1/2, c-Myc, Vimentin, and E-cadherin/N-cadherin were analyzed by real-time PCR and Western blot. Tumor volume was calculated with a specific formula, and growth.

RESULTS

The Schisandra chinensis lignans and acteoside combination decreased CCL20 expression, inhibited hepatoma proliferation and migration, and enhanced apoptosis in a dose- and time-dependent manner. Molecular analysis revealed increased E-cadherin and decreased N-cadherin, p-ERK1/2, c-Myc, and Vimentin expression, indicating ERK1/2 pathway modulation. In vivo, treated nude mice showed significantly reduced tumor growth and volume.

CONCLUSION

Schisandra chinensis lignans and acteoside potentially counteract CCL20-induced EMT, invasion, and migration in hepatocellular carcinoma cells via the ERK1/2 pathway, enhancing apoptosis. Multi-omics analysis further aids in pinpointing novel biomarkers for precision cancer therapy.

Overexpression of TNFSF11 reduces GPX4 levels and increases sensitivity to ferroptosis inducers in lung adenocarcinoma

BACKGROUND

Lung adenocarcinoma (LUAD), the most common and lethal subtype of lung cancer, continues to be a major health concern worldwide. Despite advances in targeted and immune therapies, only a minority of patients derive substantial benefits. As a result, the urgent need for novel therapeutic strategies to improve lung cancer treatment outcomes remains undiminished.

METHODS

In our study, we employed the TIMER database to scrutinize TNFSF11 expression across various cancer types. We further examined the differential expression of TNFSF11 in normal and tumor tissues utilizing the TCGA-LUAD dataset and tissue microarray, and probed the associations between TNFSF11 expression and clinicopathological parameters within the TCGA-LUAD dataset. We used the GSE31210 dataset for external validation. To identify genes strongly linked to TNFSF11, we engaged LinkedOmics and conducted a KEGG pathway enrichment analysis using the WEB-based Gene SeT AnaLysis Toolkit. Moreover, we investigated the function of TNFSF11 through gene knockdown or overexpression approaches and explore its function in tumor cells. The therapeutic impact of ferroptosis inducers in tumors overexpressing TNFSF11 were also investigated through in vivo and in vitro experiments. Through these extensive analyses, we shed light on the potential role of TNFSF11 in lung adenocarcinoma, underscoring potential therapeutic targets for this malignancy.

RESULTS

This research uncovers the overexpression of TNFSF11 in LUAD patients and its inverse correlation with peroxisome-related enzymes. By utilizing gene knockdown or overexpression assays, we found that TNFSF11 was negatively associated with GPX4. Furthermore, cells with TNFSF11 overexpression were relatively more sensitive to the ferroptosis inducers.

CONCLUSIONS

Our research has provided valuable insights into the role of TNFSF11, revealing its negative regulation of GPX4, which could be influential in crafting therapeutic strategies. These findings set the stage for further exploration into the mechanisms underpinning the relationship between TNFSF11 and GPX4, potentially opening up new avenues for precision medicine in the treatment of LUAD.

RANK/RANKL axis promotes migration, invasion, and metastasis of osteosarcoma via activating NF-κB pathway

Osteosarcoma (OS) is one of the most prevalent primary bone tumors with a high degree of metastasis and poor prognosis. Epithelial-to-mesenchymal transition (EMT) is a cellular mechanism that contributes to the invasion and metastasis of cancer cells, and OS cells have been reported to exhibit EMT-like characteristics. Our previous studies have shown that the interaction between tumor necrosis factor superfamily member 11 (TNFRSF11A; also known as RANK) and its ligand TNFSF11 (also known as RANKL) promotes the EMT process in breast cancer cells. However, whether the interaction between RANK and RANKL enhances aggressive behavior by inducing EMT in OS cells has not yet been elucidated. In this study, we showed that the interaction between RANK and RANKL increased the migration, invasion, and metastasis of OS cells by promoting EMT. Importantly, we clarified that the RANK/RANKL axis induces EMT by activating the nuclear factor-kappa B (NF-κB) pathway. Furthermore, the NF-κB inhibitor dimethyl fumarate (DMF) suppressed migration, invasion, and EMT in OS cells. Our results suggest that the RANK/RANKL axis may serve as a potential tumor marker and promising therapeutic target for OS metastasis. Furthermore, DMF may have clinical applications in the treatment of lung metastasis in patients with OS.

Chemokines and receptors in the development and progression of malignant tumors

Cancer cells, endothelial cells, inflammatory cells and various cytokines form a part of the tumor microenvironment (TME). Chemokines constitute the largest family of cytokines, and are mainly secreted by tumor cells and inflammatory cells in the TME. They play an important role in tumor development and progression by promoting tumor growth and metastasis, angiogenesis, and targeting the chemoattraction of inflammatory cells. Currently, some chemokine receptor antagonists are being used in clinical trials as targeted anti-tumor drugs. In this article, we review the roles of chemokines in the development and progression of malignant tumors based on recently published papers, taking into consideration of the new anti-tumor therapeutic strategies targeting chemokines and receptors.

RANK pathway in cancer: underlying resistance and therapeutic approaches

Cancer remains one of the deadliest diseases despite advances in treatment. Metastatic cancers are the leading cause of death for advanced cancer patients. Those with advanced cancer with osteolytic-type bone metastases have a significantly lower quality of life. A novel treatment plan is needed now more than ever for breast cancer patients with bone metastases. There are shreds of evidence that cancer cells in the bloodstream interact with the bone microenvironment and that this interaction is a contributing component to breast cancer progression. Preventing any stage of this cycle can result in anti-metastasis effects. Since RANKL interacts with its receptor RANK and plays an important role in the vicious cycle, it has proven to be a successful therapeutic target in cancer treatment. As a result, we have presented a complete overview of the RANK pathway in cancer and discussed RANK signaling and tumor microenvironment, and potential therapeutic approaches in this review.

The Role of Cytokines in Epithelial-Mesenchymal Transition in Gynaecological Cancers: A Systematic Review

Chronic inflammation has been closely linked to the development and progression of various cancers. The epithelial-mesenchymal transition (EMT) is a process involving the acquisition of mesenchymal features by carcinoma cells and is an important link between inflammation and cancer development. Inflammatory mediators in the tumour micro-environment, such as cytokines and chemokines, can promote EMT changes in cancer cells. The aim of this systematic review is to analyse the effect of cytokines on EMT in gynaecological cancers and discuss their possible therapeutic implications. A search of the databases CINAHL, Cochrane, Embase, Medline, PubMed, TRIP, and Web of Science was performed using the keywords: "cytokines" AND "epithelial mesenchymal transition OR transformation" AND "gynaecological cancer". Seventy-one articles reported that various cytokines, such as TGF-β, TNF-α, IL-6, etc., promoted EMT changes in ovarian, cervical, and endometrial cancers. The EMT changes included from epithelial to mesenchymal morphological change, downregulation of the epithelial markers E-cadherin/β-catenin, upregulation of the mesenchymal markers N-cadherin/vimentin/fibronectin, and upregulation of the EMT-transformation factors (EMT-TF) SNAI1/SNAI2/TWIST/ZEB. Cytokine-induced EMT can lead to gynaecological cancer development and metastasis and hence novel therapies targeting the cytokines or their EMT signalling pathways could possibly prevent cancer progression, reduce cancer recurrence, and prevent drug-resistance.

House dust mite-induced Akt-ERK1/2-C/EBP beta pathway triggers CCL20-mediated inflammation and epithelial-mesenchymal transition for airway remodeling

House dust mite (HDM) allergens cause inflammatory responses and chronic allergic diseases such as bronchial asthma and atopic dermatitis. Here, we investigate the mechanism by which HDM induces C-C chemokine ligand 20 (CCL20) expression to promote chronic inflammation and airway remodeling in an HDM-induced bronchial asthma mouse model. We showed that HDM increased CCL20 levels via the Akt-ERK1/2-C/EBPβ pathway. To investigate the role of CCL20 in chronic airway inflammation and remodeling, we made a mouse model of CCL20-induced bronchial asthma. Treatment of anti-CCL20Ab in this mouse model showed the reduced airway hyper-responsiveness and inflammatory cell infiltration into peribronchial region by neutralizing CCL20. In addition, CCL20 induced the Nod-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome activation through NLRP3 deubiquitination and transcriptional upregulation in BEAS-2B cells. As expected, anti-CCL20Ab markedly suppressed NLRP3 activation induced by CCL20. Moreover, HDM-induced CCL20 leads to epithelial-mesenchymal transition in the lung epithelium which appears to be an important regulator of airway remodeling in allergic asthma. We also found that anti-CCL20Ab attenuates airway inflammation and remodeling in an HDM-induced mouse model of bronchial asthma. Taken together, our results suggest that HDM-induced CCL20 is required for chronic inflammation that contributes airway remodeling in a mouse model of asthma.

RANKL biology

Since the receptor activator of nuclear factor-kappa B ligand (RANKL), its cognate receptor activator of nuclear factor-kappa B (RANK), and the decoy receptor osteoprotegerin (OPG) were discovered, a number of studies have uncovered the crucial role of the RANKL-RANK-OPG pathway in controlling the key aspect of bone homeostasis, the immune system, inflammation, cancer, and other systems under pathophysiological condition. These findings have expanded the understanding of the multifunctional biology of the RANKL-RANK-OPG pathway and led to the development of therapeutic potential targeting this pathway. The successful development and application of anti-RANKL antibody in treating diseases causing bone loss validates the utility of therapeutic approaches based on the modulation of this pathway. Moreover, recent studies have demonstrated the involvement of the RANKL-RANK pathway in osteoblast differentiation and bone formation, shedding light on the RANKL-RANK dual signaling in coupling bone resorption and bone formation. In this review, we will summarize the current understanding of the RANKL-RANK-OPG system in the context of the bone and the immune system as well as the impact of this pathway in disease conditions, including cancer development and metastasis.

The Exploration of Chemokines Importance in the Pathogenesis and Development of Endometrial Cancer

Endometrial cancer (EC) is one of the most frequent female malignancies. Because of a characteristic symptom, vaginal bleeding, EC is often diagnosed in an early stage. Despite that, some EC cases present an atypical course with rapid progression and poor prognosis. There have been multiple studies conducted on molecular profiling of EC in order to improve diagnostics and introduce personalized treatment. Chemokines-a protein family that contributes to inflammatory processes that may promote carcinogenesis-constitute an area of interest. Some chemokines and their receptors present alterations in expression in tumor microenvironment. CXCL12, which binds the receptors CXCR4 and CXCR7, is known for its impact on neoplastic cell proliferation, neovascularization and promotion of epidermal-mesenchymal transition. The CCL2-CCR2 axis additionally plays a pivotal role in EC with mutations in the LKB1 gene and activates tumor-associated macrophages. CCL20 and CCR6 are influenced by the RANK/RANKL pathway and alter the function of lymphocytes and dendritic cells. Another axis, CXCL10-CXCR3, affects the function of NK-cells and, interestingly, presents different roles in various types of tumors. This review article consists of analysis of studies that included the roles of the aforementioned chemokines in EC pathogenesis. Alterations in chemokine expression are described, and possible applications of drugs targeting chemokines are reviewed.

Adipocytokines and disease progression in endometrial cancer: a systematic review

The objective of the study was to document the effect of adipocytokines on endometrial cancer progression. A search of the databases CINAHL, Medline, PubMed, Cochrane, Web of Science, Embase and Google Scholar was performed for English language articles from January 2000 to December 2020 using the keywords: (Endometrial cancer) AND (progression OR metastasis) AND (adipocytokine OR adiponectin OR leptin OR visfatin OR IL-6 OR TNF-α OR adipokine OR cytokine). Forty-nine studies on adipocytokines have been included in this review. Adiponectin has been linked with anti-proliferative and anti-metastatic effects on endometrial cancer cells and is associated with a better prognosis. Leptin, visfatin and resistin are linked to the stimulation of endometrial cancer growth, proliferation, invasion and metastasis and are associated with worse prognosis or with a higher grade/stage of endometrial cancer. IL-6, Il-11, IL-31, IL-33, TNF-α, TGF-β1, SDF-1 and CXCR are involved in endometrial cancer cell growth and metastasis or involved in epithelial mesenchymal transformation (EMT) or associated with advanced disease. Adipocytokines have been found to directly impact endometrial cancer cell proliferation, invasion and migration. These molecules and their signalling pathways may be used to determine prognosis and course of the disease and may also be exploited as potential targets for cancer treatment and prevention of progression.

Histological Grade and Tumor Stage Are Correlated with Expression of Receptor Activator of Nuclear Factor Kappa b (Rank) in Epithelial Ovarian Cancers

The receptor activator of nuclear factor kappa B (RANK) is becoming recognized as a master regulator of tumorigenesis, yet its role in gynecological cancers remains mostly unexplored. We investigated whether there is a gradation of RANK protein and mRNA expression in epithelial ovarian cancer (EOC) according to malignancy and tumor staging. Immunohistochemical expression of RANK was examined in a cohort of 135 (benign n = 29, borderline n= 23 and malignant n = 83) EOCs. Wild type and truncated RANK mRNA isoform quantification was performed in a cohort of 168 (benign n = 26, borderline n = 13 and malignant n = 129) EOCs. RANK protein and mRNA values were increased in malignant vs. benign or borderline conditions across serous, mucinous and endometrioid cancer subtypes. Additionally, a trend of increased RANK values with staging was observed for the mucinous and serous histotype. Thus, increased expression of RANK appears associated with the evolution of disease to the onset of malignancy in EOC. Moreover, in some EOC histotypes, RANK expression is additionally associated with clinicopathological markers of tumor aggressiveness, suggesting a role in further progression of tumor activity.

Identification and Validation of MSX1 as a Key Candidate for Progestin Resistance in Endometrial Cancer

Purpose

Progestin resistance is a critical obstacle for endometrial conservative therapy. Therefore, studies to acquire a more comprehensive understanding of the mechanisms are urgent. However, the pivotal molecules are still unexplored.

Materials and Methods

We downloaded GSE121367 from the GEO database. The “limma” R language package was applied to identify differentially expressed genes (DEGs). We conducted Gene Set Enrichment Analysis (GSEA) and Gene Set Variation Analysis (GSVA). Protein–protein interaction was constructed by STRING and visualized in Cytoscape. The tumor immune microenvironment was explored by the TISIDB database. Methylation validation and overall survival analysis were conducted by the TCGA database. In addition, the upstream modulators of hub genes were predicted by miRTarBase and Network Analyst databases. The expression levels of candidate genes were validated by quantitative real-time PCR (qRT-PCR), Western blot, and immunohistochemical assay (IHC). Cell growth, clone formation, migration, invasion, and wound healing assays were studied to explore the role of MSX1 in progestin resistance in vitro.

Results

A total of 3,282 DEGs were identified and they were mostly enriched in the cell adhesion pathway. We screened out ten hub genes whose genomic alteration rates were low based on the current endometrial carcinoma sample sets. Has-miR-335-5p, has-miR-124-3p, MAZ, and TFDP1 were the most prominent upstream regulators. The methylation status of CDH1, JAG1, EPCAM, and MSX1 was decreased, corresponding to their high protein expression, which also predicted better overall survival. The homeobox protein of MSX1 showed significant tissue specificity and better prognostic value and its knockdown inhibited epithelial–mesenchymal transitions (EMT) and enhanced progesterone efficacy.

Conclusion

Our study identified that the gene of MSX1 promised to be the specific indicator and therapeutic target for progestin resistance. This would shed new light on the underlying biological mechanism to overcome progestin resistance of endometrial cancer.

High serum CCL20 is associated with tumor progression in penile cancer

Serum cancer biomarker has been proven to be very valuable in cancer diagnosis, disease monitoring and prognosis assessment, despite there is still a lack of serum biomarker for penile cancer (PC). Our initial analysis on public GEO dataset identified CCL20 as a top C-C motif ligand (CCL) gene enriched in PC. The patients with PC exhibited markedly higher preoperative serum CCL20 level than healthy control. The area under the curve (AUC) was 0.855 with the sensitivity of 72.4%, and specificity of 93.5% to distinguish PC. Preoperative serum CCL20 level was significantly associated with clinicopathological characteristics including T stage (P=0.005), nodal status (P=0.008), and pelvic lymph node metastasis (P=0.007). PC Patients with high serum CCL20 level had shorter disease-free survival compared to those with low level (P<0.001). Cox regression analysis showed that serum CCL20 level could serve as an independent prognostic factor for disease-free survival with a HR of 3.980 (95% CI: 1.209-13.098, P=0.023). Furthermore, CCL20 expression was observed in PC tissues and cell lines. Knockdown of CCL20 expression markedly suppressed malignant phenotypes (cell proliferation, clonogenesis, apoptosis escape, migration and invasion), attenuated STAT3 and AKT signaling and reduced MMP2/9 secretion in PC cell lines. Consistently, CCL20 and its receptor CCR6 exhibited correlated expression pattern in PC tissues. In conclusion, serum CCL20 level might serve as a potential diagnostic and prognostic cancer biomarker for PC. CCL20 might activate multiple downstream oncogenic signaling pathways (STAT3, AKT, MMP2/9) to promote malignant progression of PC, which may warrant further investigation in the future.

Targeting the RANKL/RANK/OPG Axis for Cancer Therapy

RANKL and RANK are expressed in different cell types and tissues throughout the body. They were originally described for their essential roles in bone remodeling and the immune system but have subsequently been shown to provide essential signals from regulating mammary gland homeostasis during pregnancy to modulating tumorigenesis. The success of RANKL/RANK research serves as a paragon for translational research from the laboratory to the bedside. The case in point has been the development of Denosumab, a RANKL-blocking monoclonal antibody which has already helped millions of patients suffering from post-menopausal osteoporosis and skeletal related events in cancer. Here we will provide an overview of the pathway from its origins to its clinical relevance in disease, with a special focus on emerging evidence demonstrating the therapeutic value of targeting the RANKL/RANK/OPG axis not only in breast cancer but also as an addition to the cancer immunotherapy arsenal.

Actin‑like protein 8 executes a promoting function in the malignant progression of endometrial cancer: identification of a promising biomarker

Endometrial cancer (EC) is generally considered as a disease that affects older women. We attempt to explore the role of actin‑like protein 8 (ACTL8) in EC and how it achieves its function. Based on the data from The Cancer Genome Atlas (TCGA), we found that ACTL8 expression was up-regulated in EC tissues and correlated with shorter overall survival of EC patients. ACTL8 expression was significantly associated with age, clinical-stage, or grade. Cox proportional hazards model analysis revealed that ACTL8 expression, grade, and clinical-stage were promising independent prognostic factors of EC. Knockdown of ACTL8 repressed the proliferative, migrating and invading capabilities of human EC cell lines KLE and Ishikawa. Silencing ACTL8 up-regulated the negative cell cycle regulator p21 and epithelial marker E-cadherin, and down-regulated the positive cell cycle regulator Cyclin A, mesenchymal markers MMP-9 and N-cadherin in KLE cells. Collectively, these outcomes illustrated that ACTL8 might act as a tumor facilitator during EC progression.

DRG Neurons Promote Perineural Invasion of Endometrial Cancer via GluR2

Background: Perineural invasion (PNI) is correlated with negative prognosis in multiple cancers, but its role in endometrial cancer (EC) is still largely unknown; thus, targeted treatment for nerve infiltration is lacking as well.

Methods: The interaction between nerve and EC cells were investigated by in vitro neural invasion assay and transwell coculture system. Then the nerve-related receptor gene glutamate ionotropic receptor AMPA type subunit 2 (GRIA2) was detected in EC tissues and cells using PCR array, western blotting, and immunohistochemistry. The role of GluR2 (gene name GRIA2) on EC proliferation, migration and invasion was evaluated by a GluR2 antagonist and shRNA. At the same time, the neurotransmitter effect on GluR2 (glutamate) from the cocultured conditional medium was measured using high-performance liquid chromatography (HPLC).

Results: EC cell line Ishikawa (ISK) showed the ability to migrate along neurites in vitro and the numbers of migrated/invaded EC cells in the DRG neuron coculture group were significantly increased. The expression of GluR2 in EC tissue was found to be higher than that in para-carcinoma tissue. After GluR2 antagonist and GluR2 shRNA treatment, the proliferation, migration and invasion of ISK cells was markedly inhibited. Moreover, the ability of DRG neurons to promote the migration and invasion of ISK cells could also be attenuated by downregulation of GluR2, and the concentration of the neurotransmitter glutamate was notably increased in the coculture conditional medium compared to that in the DRG neuron or ISK cells alone.

Conclusions: DRG neurons promote metastasis of EC cells via GluR2, which might be a risk factor for PNI in EC. Moreover, the perineural system may promote tumor invasion and metastasis under certain circumstances.

Harnessing the versatile role of OPG in bone oncology: counterbalancing RANKL and TRAIL signaling and beyond

More than 2 decades ago, the discovery of osteoprotegerin (OPG) as inhibitor of the receptor of activator of nuclear factor Kb (RANK) ligand (RANKL) revolutionized our understanding of bone biology and oncology. Besides acting as decoy receptor for RANKL, OPG acts as decoy receptor for tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). OPG, RANKL, and TRAIL are ubiquitously expressed, stimulating per se pivotal signaling cascades implicated in cancer. In the context of cancer cell-bone cell interactions, cancer cells skew the OPG/RANKL/RANK (RANKL cognate receptor) balance towards bone destruction and tumor growth through favoring the RANKL/RANK interface, circumventing OPG. Numerous preclinical and clinical studies demonstrate the dual role of OPG in cancer: antitumor and tumor-promoting. OPG potentially conveys an antitumor signal through inhibiting the tumor-promoting RANKL signaling-both the osteoclast-dependent and the osteoclast-independent-and the tumor-promoting TRAIL signaling. On the other hand, the presumed tumor-promoting functions of OPG are: (i) abrogation of TRAIL-induced apoptosis of cancer cells; (ii) abrogation of RANKL-induced antitumor immunity; and (iii) stimulation of oncogenic and prometastatic signaling cascades downstream of the interaction of OPG with diverse proteins. The present review dissects the role of OPG in bone oncology. It presents the available preclinical and clinical data sustaining the dual role of OPG in cancer and focuses on the imbalanced RANKL/RANK/OPG interplay in the landmark "vicious cycle" of skeletal metastatic disease, osteosarcoma, and multiple myeloma. Finally, current challenges and future perspectives in exploiting OPG signaling in bone oncology therapeutics are discussed.

The Non-Bone-Related Role of RANK/RANKL Signaling in Cancer

RANK ligand (RANKL) is a member of the tumor necrosis factor alpha superfamily of cytokines. It is the only known ligand binding to a membrane receptor named receptor activator of nuclear factor-kappa B (RANK), thereby triggering recruitment of TNF receptor-associated factor (TRAF) adaptor proteins and activation of downstream pathways. RANK/RANKL signaling is controlled by a decoy receptor, osteoprotegerin (OPG), but also has additional more complex levels of regulation. It is crucial for the differentiation of bone-resorbing osteoclasts and is deregulated in disease processes such as osteoporosis and cancer bone metastasis. Cells expressing RANK and RANKL are commonly found in the tumor environment. In many tumor types, the RANK/RANKL pathway is overexpressed, and this is in most cases correlated with poor prognosis. RANK signaling plays an important role in the innate and adaptive immune response, generates regulatory T (Treg) cells, and increases the production of cytokines. It is also involved in chemo resistance in vitro. Recent evidence suggests that RANKL blockade improves the efficacy of anti-CTLA-4 antibodies against solid tumors and experimental metastasis. Therefore, there is increasing interest to use RANKL inhibition as an immunomodulatory strategy in an attempt to make immune-resistant tumor responsive to immune therapy.

CCL20 Signaling in the Tumor Microenvironment

CCL20, as a chemokine, plays an important role in rheumatoid arthritis, psoriasis, and other diseases by binding to its receptor CCR6. Recent 10 years' research has demonstrated that CCL20 also contributes to the progression of many cancers, such as liver cancer, colon cancer, breast cancer, pancreatic cancer, and gastric cancer. This article reviews and discusses the previous studies on CCL20 roles in cancers from the aspects of its specific effects on various cancers, its remodeling on tumor microenvironment (TME), its synergistic effects with other cytokines in tumor microenvironment, and the specific mechanisms of CCL20 signal activation, illustrating CCL20 signaling in TME from multiple directions.

Medroxyprogesterone acetate causes the alterations of endoplasmic reticulum related mRNAs and lncRNAs in endometrial cancer cells

BACKGROUND

Progestin is effective to promote endometrial cancer (EC) cells apoptosis, however, continuous progestin administration causes low level of progestin receptor B (PRB), further resulting in progestin resistance. Here, we performed microarray analysis on Ishikawa cells (PRB+) treated with medroxyprogesterone acetate (MPA) to explore the molecular mechanism underlying the inhibitory influence of MPA on PRB+ EC cells.

METHODS

Microarray analysis was performed by using Ishikawa cells (PRB+) treated with MPA. Differentially expressed mRNA and long noncoding RNAs (lncRNAs) were identified. Furthermore, the functions of these mRNAs and lncRNAs were predicted by functional enrichment analysis. QRT-PCR was further performed to verify the microarray data.

RESULTS

A total of 358 differentially expressed genes and 292 lncRNAs were identified in Ishikawa cells (PRB+) treated with MPA. QRT-PCR verified these data. Functional enrichment analysis identified endoplasmic reticulum (ER) stress as the key pathway involved in the inhibitory effect of MPA on EC cells. And the ER stress apoptotic molecule CHOP and ER stress related molecule HERPUD1 were both highly expressed in Ishikawa cells (PRB+) treated with MPA. Co-expression analysis showed lnc-CETP-3 was highly correlated with CHOP and HERPUD1, suggesting it might participate in ER stress pathway-related EC cell apoptosis caused by MPA. In addition, compared with untreated cells, lnc-CETP-3, CHOP and HERPUD1 were significantly up-regulated in Ishikawa cells (PRB+) treated with MPA, whereas they have no statistical significance in KLE cells (PRB-).

CONCLUSIONS

MPA may activate ER stress by progesterone-PRB pathway to up-regulate CHOP expression, which may be one of the molecular mechanisms underlying the inhibitory effect of MPA on EC cells with PRB+. Lnc-CETP-3 might be involved in this process. These findings may provide therapeutic targets for EC patients with PRB-, and resistance-related targets to increase the sensitivity of MPA on EC cells.

RANK-RANKL Signaling in Cancer of the Uterine Cervix: A Review

RANK ligand (RANKL) is a member of the tumor necrosis factor alpha superfamily of cytokines. It is the only known ligand binding to a membrane receptor named receptor activator of nuclear factor-kappa B (RANK), thereby triggering recruitment of tumor necrosis factor (TNF) receptor associated factor (TRAF) adaptor proteins and activation of downstream pathways. RANK/RANKL signaling is controlled by a decoy receptor called osteoprotegerin (OPG), but also has additional more complex levels of regulation. The existing literature on RANK/RANKL signaling in cervical cancer was reviewed, particularly focusing on the effects on the microenvironment. RANKL and RANK are frequently co-expressed in cervical cancer cells lines and in carcinoma of the uterine cervix. RANKL and OPG expression strongly increases during cervical cancer progression. RANKL is directly secreted by cervical cancer cells, which may be a mechanism they use to create an immune suppressive environment. RANKL induces expression of multiple activating cytokines by dendritic cells. High RANK mRNA levels and high immunohistochemical OPG expression are significantly correlated with high clinical stage, tumor grade, presence of lymph node metastases, and poor overall survival. Inhibition of RANKL signaling has a direct effect on tumor cell proliferation and behavior, but also alters the microenvironment. Abundant circumstantial evidence suggests that RANKL inhibition may (partially) reverse an immunosuppressive status. The use of denosumab, a monoclonal antibody directed to RANKL, as an immunomodulatory strategy is an attractive concept which should be further explored in combination with immune therapy in patients with cervical cancer.

Uterine double-conditional inactivation of Smad2 and Smad3 in mice causes endometrial dysregulation, infertility, and uterine cancer

SMAD2 and SMAD3 are downstream proteins in the transforming growth factor-β (TGF β) signaling pathway that translocate signals from the cell membrane to the nucleus, bind DNA, and control the expression of target genes. While SMAD2/3 have important roles in the ovary, we do not fully understand the roles of SMAD2/3 in the uterus and their implications in the reproductive system. To avoid deleterious effects of global deletion, and given previous data showing redundant function of Smad2 and Smad3, a double-conditional knockout was generated using progesterone receptor-cre (Smad2/3 cKO) mice. Smad2/3 cKO mice were infertile due to endometrial hyperproliferation observed as early as 6 weeks of postnatal life. Endometrial hyperplasia worsened with age, and all Smad2/3 cKO mice ultimately developed bulky endometrioid-type uterine cancers with 100% mortality by 8 months of age. The phenotype was hormone-dependent and could be prevented with removal of the ovaries at 6 weeks of age but not at 12 weeks. Uterine tumor epithelium was associated with decreased expression of steroid biosynthesis genes, increased expression of inflammatory response genes, and abnormal expression of cell cycle checkpoint genes. Our results indicate the crucial role of SMAD2/3 in maintaining normal endometrial function and confirm the hormone-dependent nature of SMAD2/3 in the uterus. The hyperproliferation of the endometrium affected both implantation and maintenance of pregnancy. Our findings generate a mouse model to study the roles of SMAD2/3 in the uterus and serve to provide insight into the mechanism by which the endometrium can escape the plethora of growth regulatory proteins.

Alterations in PD-L1 Expression Associated with Acquisition of Resistance to ALK Inhibitors in ALK-Rearranged Lung Cancer

PURPOSE

The purpose of this study was to evaluate the relationships between the resistance of anaplastic lymphoma kinase (ALK)‒positive non-small cell lung cancer (NSCLC) to ALK inhibitors and the programmed cell death-1/programmed cell death-ligand 1 (PD-L1) pathway, we evaluated alterations in PD-L1 following acquisition of resistance to ALK inhibitors in ALK-positive lung cancer.

MATERIALS AND METHODS

We established ALK inhibitor-resistant cell lines (H3122CR1, LR1, and CH1) by exposing the parental H3122 ALK-translocated NSCLC cell line to ALK inhibitors. Then, the double-resistant cell lines H3122CR1LR1 and CR1CH1 were developed by exposing the H3122CR1 to other ALK inhibitors. We compared the alterations in PD-L1 expression levels using western blotting, flow cytometry, and quantitative polymerase chain reaction. We also investigated gene expression using RNA sequencing. The expression of PD-L1 in the tumors from 26 ALK-positive metastatic NSCLC patients (11 ALK inhibitor-naïve and 15 ALK inhibitor-resistant patients) was assessed by immunohistochemistry and analyzed.

RESULTS

PD-L1 was expressed at higher levels in ALK inhibitor-resistant cell lines than in the ALK inhibitor-naïve parental cell line at the total protein, surface protein, and mRNA levels. Furthermore, PD-L1 expression in the double-resistant cell lines was much higher than that in the single resistant cell lines. RNA sequencing demonstrated that expression of immune-related genes were largely involved in ALK inhibitor resistance. The mean value of the PD-L1 H-score was 6.5 pre-treatment and 35.0 post-treatment, and the fold difference was 5.42 (p=0.163).

CONCLUSION

PD-L1 expression increased following acquisition of ALK inhibitor resistance in ALK-positive NSCLC cell lines and tumors.

RANK/RANKL signaling inhibition may improve the effectiveness of checkpoint blockade in cancer treatment

Binding between the receptor activator of nuclear factor-kB (RANK) and its ligand (RANKL) triggers recruitment of TNF receptor associated factor (TRAF) adaptor proteins and activation of downstream pathways. RANK/RANKL signaling is controlled by a decoy receptor called osteoprotegerin (OPG) which interacts with RANKL. Additional networks regulating RANK/RANKL signaling are active in a context specific manner. RANK/RANKL signaling is essential for the differentiation of bone-resorbing osteoclasts, and is deregulated in pathological processes such as postmenopausal osteoporosis or cancer induced bone destruction. Cells expressing RANK and RANKL are commonly found in the tumor microenvironment. The RANKL/RANK pathway is often overexpressed in tumors of the breast, prostate, endometrium, cervix, stomach, oesophagus and bladder, thyroid and correlated with poor prognosis. RANK signaling plays an important role in the innate and adaptive immune response as it generates regulatory T (Treg) cells and increases production of cytokines. RANK expression induces chemoresistance in vitro through the activation of multiple signal transduction pathways. RANKL blockade improves the efficacy of anti-CTLA-4 monoclonal antibodies against solid tumors and experimental metastases. As RANK inhibition enhances the immune response there is an increasing interest in combining it with immune therapy in an attempt to sensitize immune resistant tumors to immune therapies. Several studies are ongoing to assess this concept. The role of RANK/RANKL inhibition should be further pursued as an immunomodulatory strategy in combination with other treatment modalities.

Pancreatic carcinoma cells colonizing the liver modulate the expression of their extracellular matrix genes

Liver is the main target of pancreatic ductal adenocarcinoma (PDAC) metastasis. Here, a rat model was used for analysing gene expression modulations during liver colonization. ASML PDAC cells were injected to isogenic rats and re-isolated at various stages of liver colonization for RNA isolation or re-cultivation. Microarrays were used for analysing mRNA and miRNA profiles of expres­sion. The results were partially confirmed by (q) RT-PCR and western blot. Selected genes were knocked down by siRNA transfection and the resulting cell behaviour was analysed. The ratio of up- and down regulated genes decreased from 20:1 (early stage) to 1.2:1 (terminal stage). Activation of cancer relevant gene categories varied between stages of liver colonization, with a nadir in the intermediate stage. The cells' environment triggered up to hundredfold changed expression for collagens, matrix metalloproteinases and chemokines. These modulations in mRNA expression were related to respective changes at miRNA levels. Gene expression knockdown of Mmp2 and Ccl20, which were highly modulated in vivo, was correlated with reduced prolif­eration and migration in vitro. Thus, target genes and temporal alterations in expression were identified, which can serve as basis for future therapeutic or diagnostic purposes.

Receptor Activator of Nuclear Factor Kappa B (RANK) and Clinicopathological Variables in Endometrial Cancer: A Study at Protein and Gene Level

The system integrated by the receptor activator of nuclear factor kappa B (RANK) and its ligand, RANKL, modulates the role of hormones in the genesis and progression of breast tumors. We investigated whether the expression of RANK was related with clinicopathological features of primary endometrial tumors. Immunohistochemistry was used in an endometrial cancer tissue array containing samples from 36 tumors. The amount of RANK mRNA was examined in a tissue scan cDNA array containing cDNA from 40 tumors. Normal endometrium was examined for comparison. Immunohistochemical analyses showed that RANK expression was higher in malignant than in normal endometrium (p < 0.05). RANK expression was related to histological grade (Pearson correlation index = 0.484, p < 0.001), but not to tumor stage or to age of the women. The gene expression was similar in malignant and normal endometrium. The study of RANK isoforms confirmed that the overall relative abundance of the three clearly identified transcripts was similar in normal and pathological endometrium. RANK protein expression increased from normal to malignant endometrium, and the expression level was related with tumor grade but not with stage or the age of subjects in endometrial cancer. In contrast, similar comparisons showed no change in RANK gene expression.

Identification of Key Candidate Genes and Pathways in Endometrial Cancer by Integrated Bioinformatical Analysis

Endometrial Cancer is the most common female genital tract malignancy, its pathogenesis is complex, not yet fully described. To identify key genes of Endometrial Cancer we downloaded the gene chip GSE17025 from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) were identified through the GEO2R analysis tool. Functional and pathway enrichment analysis were performed for DEGs using DAVID database. The network of protein–protein-interaction (PPI) was established by STRING website and visualized by Cytoscape. Then, functional and pathway enrichment analysis of DEGS were performed by DAVID database. A total of 1000 significant differences genes were obtained, contain 362 up-regulated genes and 638 down-regulated genes. PCDH10, SLC6A2, OGN, SFRP4, TRH, ANGPTL, FOSB are down-regulated genes. The gene of IGH, CCL20, ELF5, LTF, ASPM expression level in tumor patients are up-regulated. Biological function of enrichment include metabolism of xenobiotics by cytochrome P450, MAPK signaling pathway, Serotonergic synapse, Protein digestion and absorption, IL-17 signaling pathway, Chemokine signaling pathway, HIF-1 signaling pathway, p53 signaling pathway. All in all, the current study to determine endometrial differentially expressed genes and biological function, comprehensive analysis of intrauterine membrane carcinoma pathogenesis mechanism, and might be used as molecular targets and diagnostic biomarkers for the treatment of endometrial cancer.

BRCA1 haploinsufficiency cell-autonomously activates RANKL expression and generates denosumab-responsive breast cancer-initiating cells

Denosumab, a monoclonal antibody to the receptor activator of nuclear factor-κB ligand (RANKL), might be a novel preventative therapy for BRCA1-mutation carriers at high risk of developing breast cancer. Beyond its well-recognized bone-targeted activity impeding osteoclastogenesis, denosumab has been proposed to interfere with the cross-talk between RANKL-producing sensor cells and cancer-initiating RANK+ responder cells that reside within premalignant tissues of BRCA1-mutation carriers. We herein tested the alternative but not mutually exclusive hypothesis that BRCA1 deficiency might cell-autonomously activate RANKL expression to generate cellular states with cancer stem cell (CSC)-like properties. Using isogenic pairs of normal-like human breast epithelial cells in which the inactivation of a single BRCA1 allele results in genomic instability, we assessed the impact of BRCA1 haploinsufficiency on the expression status of RANK and RANKL. RANK expression remained unaltered but RANKL was dramatically up-regulated in BRCA1mut/+ haploinsufficient cells relative to isogenic BRCA1+/+ parental cells. Neutralizing RANKL with denosumab significantly abrogated the ability of BRCA1 haploinsufficient cells to survive and proliferate as floating microtumors or "mammospheres" under non-adherent/non-differentiating conditions, an accepted surrogate of the relative proportion and survival of CSCs. Intriguingly, CSC-like states driven by epithelial-to-mesenchymal transition or HER2 overexpression traits responded to some extent to denosumab. We propose that breast epithelium-specific mono-allelic inactivation of BRCA1 might suffice to cell-autonomously generate RANKL-addicted, denosumab-responsive CSC-like states. The convergent addiction to a hyperactive RANKL/RANK axis of CSC-like states from genetically diverse breast cancer subtypes might inaugurate a new era of cancer prevention and treatment based on denosumab as a CSC-targeted agent.

Epithelial-to-Mesenchymal Transition in the Female Reproductive Tract: From Normal Functioning to Disease Pathology

Epithelial-to-mesenchymal transition (EMT) is a physiological process that is vital throughout the human lifespan. In addition to contributing to the development of various tissues within the growing embryo, EMT is also responsible for wound healing and tissue regeneration later in adulthood. In this review, we highlight the importance of EMT in the development and normal functioning of the female reproductive organs (the ovaries and the uterus) and describe how dysregulation of EMT can lead to pathological conditions, such as endometriosis, adenomyosis, and carcinogenesis. We also summarize the current literature relating to EMT in the context of ovarian and endometrial carcinomas, with a particular focus on how molecular mechanisms and the tumor microenvironment can govern cancer cell plasticity, therapy resistance, and metastasis.

Blocking epithelial-to-mesenchymal transition in glioblastoma with a sextet of repurposed drugs: the EIS regimen

This paper outlines a treatment protocol to run alongside of standard current treatment of glioblastoma- resection, temozolomide and radiation. The epithelial to mesenchymal transition (EMT) inhibiting sextet, EIS Regimen, uses the ancillary attributes of six older medicines to impede EMT during glioblastoma. EMT is an actively motile, therapy-resisting, low proliferation, transient state that is an integral feature of cancers’ lethality generally and of glioblastoma specifically. It is believed to be during the EMT state that glioblastoma’s centrifugal migration occurs. EMT is also a feature of untreated glioblastoma but is enhanced by chemotherapy, by radiation and by surgical trauma. EIS Regimen uses the antifungal drug itraconazole to block Hedgehog signaling, the antidiabetes drug metformin to block AMP kinase (AMPK), the analgesic drug naproxen to block Rac1, the anti-fibrosis drug pirfenidone to block transforming growth factor-beta (TGF-beta), the psychiatric drug quetiapine to block receptor activator NFkB ligand (RANKL) and the antibiotic rifampin to block Wnt- all by their previously established ancillary attributes. All these systems have been identified as triggers of EMT and worthy targets to inhibit. The EIS Regimen drugs have a good safety profile when used individually. They are not expected to have any new side effects when combined. Further studies of the EIS Regimen are needed.

Identification of subepithelial mesenchymal cells that induce IgA and diversify gut microbiota

Immunoglobulin A (IgA) maintains a symbiotic equilibrium with intestinal microbes. IgA induction in the gut-associated lymphoid tissues (GALTs) is dependent on microbial sampling and cellular interaction in the subepithelial dome (SED). However it is unclear how IgA induction is predominantly initiated in the SED. Here we show that previously unrecognized mesenchymal cells in the SED of GALTs regulate bacteria-specific IgA production and diversify the gut microbiota. Mesenchymal cells expressing the cytokine RANKL directly interact with the gut epithelium to control CCL20 expression and microfold (M) cell differentiation. The deletion of mesenchymal RANKL impairs M cell-dependent antigen sampling and B cell-dendritic cell interaction in the SED, which results in a reduction in IgA production and a decrease in microbial diversity. Thus, the subepithelial mesenchymal cells that serve as M cell inducers have a fundamental role in the maintenance of intestinal immune homeostasis.

RANK-RANKL signalling in cancer

Oncogenic events combined with a favourable environment are the two main factors in the oncological process. The tumour microenvironment is composed of a complex, interconnected network of protagonists, including soluble factors such as cytokines, extracellular matrix components, interacting with fibroblasts, endothelial cells, immune cells and various specific cell types depending on the location of the cancer cells (e.g. pulmonary epithelium, osteoblasts). This diversity defines specific "niches" (e.g. vascular, immune, bone niches) involved in tumour growth and the metastatic process. These actors communicate together by direct intercellular communications and/or in an autocrine/paracrine/endocrine manner involving cytokines and growth factors. Among these glycoproteins, RANKL (receptor activator nuclear factor-κB ligand) and its receptor RANK (receptor activator nuclear factor), members of the TNF and TNFR superfamilies, have stimulated the interest of the scientific community. RANK is frequently expressed by cancer cells in contrast with RANKL which is frequently detected in the tumour microenvironment and together they participate in every step in cancer development. Their activities are markedly regulated by osteoprotegerin (OPG, a soluble decoy receptor) and its ligands, and by LGR4, a membrane receptor able to bind RANKL. The aim of the present review is to provide an overview of the functional implication of the RANK/RANKL system in cancer development, and to underline the most recent clinical studies.