The leukemia inhibitory factor (LIF) and p21 mediate the TGFβ tumor suppressive effects in human cutaneous melanoma

Multiple Endocrine Neoplasia Type 1 Regulates TGFβ-Mediated Suppression of Tumor Formation and Metastasis in Melanoma

Over the past few decades, the worldwide incidence of cutaneous melanoma, a malignant neoplasm arising from melanocytes, has been increasing markedly, leading to the highest rate of skin cancer-related deaths. While localized tumors are easily removed by excision surgery, late-stage metastatic melanomas are refractory to treatment and exhibit a poor prognosis. Consequently, unraveling the molecular mechanisms underlying melanoma tumorigenesis and metastasis is crucial for developing novel targeted therapies. We found that the multiple endocrine neoplasia type 1 (MEN1) gene product Menin is required for the transforming growth factor beta (TGFβ) signaling pathway to induce cell growth arrest and apoptosis in vitro and prevent tumorigenesis in vivo in preclinical xenograft models of melanoma. We further identified point mutations in two MEN1 family members affected by melanoma that led to proteasomal degradation of the MEN1 gene product and to a loss of TGFβ signaling. Interestingly, blocking the proteasome degradation pathway using an FDA-approved drug and RNAi targeting could efficiently restore MEN1 expression and TGFβ transcriptional responses. Together, these results provide new potential therapeutic strategies and patient stratification for the treatment of cutaneous melanoma.

Transforming Growth Factor-β/Smad Signaling Inhibits Melanoma Cancer Stem Cell Self-Renewal, Tumor Formation and Metastasis

The secreted protein transforming growth factor-beta (TGFβ) plays essential roles, ranging from cell growth regulation and cell differentiation in both normal and cancer cells. In melanoma, TGFβ acts as a potent tumor suppressor in melanoma by blocking cell cycle progression and inducing apoptosis. In the present study, we found TGFβ to regulate cancer stemness in melanoma through the Smad signaling pathway. We discovered that TGFβ/Smad signaling inhibits melanosphere formation in multiple melanoma cell lines and reduces expression of the CD133+ cancer stem cell subpopulation in a Smad3-dependent manner. Using preclinical models of melanoma, we further showed that preventing Smad3/4 signaling, by means of CRISPR knockouts, promoted both tumorigenesis and lung metastasis in vivo. Collectively, our results define new functions for the TGFβ/Smad signaling axis in melanoma stem-cell maintenance and open avenues for new therapeutic approaches to this disease.

Analysis on tumor immune microenvironment and construction of a prognosis model for immune-related skin cutaneous melanoma

OBJECTIVES

Malignant melanoma is a highly malignant and heterogeneous skin cancer. Although immunotherapy has improved survival rates, the inhibitory effect of tumor microenvironment has weakened its efficacy. To improve survival and treatment strategies, we need to develop immune-related prognostic models. Based on the analysis of the Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and Sequence Read Archive (SRA) database, this study aims to establish an immune-related prognosis prediction model, and to evaluate the tumor immune microenvironment by risk score to guide immunotherapy.

METHODS

Skin cutaneous melanoma (SKCM) transcriptome sequencing data and corresponding clinical information were obtained from the TCGA database, differentially expressed genes were analyzed, and prognostic models were developed using univariate Cox regression, the LASSO method, and stepwise regression. Differentially expressed genes in prognostic models confirmed by real-time reverse transcription PCR (real-time RT-PCR) and Western blotting. Survival analysis was performed by using the Kaplan-Meier method, and the effect of the model was evaluated by time-dependent receiver operating characteristic curve as well as multivariate Cox regression, and the prognostic model was validated by 2 GEO melanoma datasets. Furthermore, correlations between risk score and immune cell infiltration, Estimation of STromal and Immune cells in MAlignant Tumor tissues using Expression data (ESTIMATE) score, immune checkpoint mRNA expression levels, tumor immune cycle, or tumor immune micro-environmental pathways were analyzed. Finally, we performed association analysis for risk score and the efficacy of immunotherapy.

RESULTS

We identified 4 genes that were differentially expressed in TCGA-SKCM datasets, which were mainly associated with the tumor immune microenvironment. A prognostic model was also established based on 4 genes. Among 4 genes, the mRNA and protein levels of killer cell lectin like receptor D1 (KLRD1), leukemia inhibitory factor (LIF), and cellular retinoic acid binding protein 2 (CRABP2) genes in melanoma tissues differed significantly from those in normal skin (all P<0.01). The prognostic model was a good predictor of prognosis for patients with SKCM. The patients with high-risk scores had significantly shorter overall survival than those with low-risk scores, and consistent results were achieved in the training cohort and multiple validation cohorts (P<0.001). The risk score was strongly associated with immune cell infiltration, ESTIMATE score, immune checkpoint mRNA expression levels, tumor immune cycle, and tumor immune microenvironmental pathways (P<0.001). The correlation analysis showed that patients with the high-risk scores were in an inhibitory immune microenvironment based on the prognostic model (P<0.01).

CONCLUSIONS

The immune-related SKCM prognostic model constructed in this study can effectively predict the prognosis of SKCM patients. Considering its close correlation to the tumor immune microenvironment, the model has some reference value for clinical immunotherapy of SKCM.

Characterization of the pro-inflammatory roles of the goldfish (Carassius auratus L.) M17 protein

The interleukin-6 family of cytokines possesses a diversity of roles with significant redundancy. The roles of these molecules have been relatively well characterized in mammals, with limited attention in other species. Progress has been made in the discovery of homologous molecules in fish. Here we report the characterization of pro-inflammatory properties of recombinant goldfish M17. Recombinant goldfish M17 enhanced phagocytosis, primed production of reactive oxygen intermediates, and was chemotactic to macrophages. Treatment of goldfish macrophages with LPS, heat-killed and live Aeromonas hydrophila resulted in higher M17 mRNA levels. Recombinant M17 (RgM17) induced dose-dependent production of IFNγ and IL-1β1 in goldfish macrophages. Furthermore, treatment of macrophages with rgM17 resulted in upregulation of transcription factors that were important in the differentiation of myeloid progenitors into monocytes/macrophages (Runx1 and GATA2). Our results indicate that goldfish M17 is an essential inflammatory cytokine for proliferation and differentiation of goldfish progenitor cells.

TGF-β is elevated in hyperuricemic individuals and mediates urate-induced hyperinflammatory phenotype in human mononuclear cells

BACKGROUND

Soluble urate leads to a pro-inflammatory phenotype in human monocytes characterized by increased production of IL-1β and downregulation of IL-1 receptor antagonist, the mechanism of which remains to be fully elucidated. Previous transcriptomic data identified differential expression of genes in the transforming growth factor (TGF)-β pathway in monocytes exposed to urate in vitro. In this study, we explore the role of TGF-β in urate-induced hyperinflammation in peripheral blood mononuclear cells (PBMCs).

METHODS

TGF-β mRNA in unstimulated PBMCs and protein levels in plasma were measured in individuals with normouricemia, hyperuricemia and gout. For in vitro validation, PBMCs of healthy volunteers were isolated and treated with a dose ranging concentration of urate for assessment of mRNA and pSMAD2. Urate and TGF-β priming experiments were performed with three inhibitors of TGF-β signalling: SB-505124, 5Z-7-oxozeaenol and a blocking antibody against TGF-β receptor II.

RESULTS

TGF-β mRNA levels were elevated in gout patients compared to healthy controls. TGF-β-LAP levels in serum were significantly higher in individuals with hyperuricemia compared to controls. In both cases, TGF-β correlated positively to serum urate levels. In vitro, urate exposure of PBMCs did not directly induce TGF-β but did enhance SMAD2 phosphorylation. The urate-induced pro-inflammatory phenotype of monocytes was partly reversed by blocking TGF-β.

CONCLUSIONS

TGF-β is elevated in individuals with hyperuricemia and correlated to serum urate concentrations. In addition, the urate-induced pro-inflammatory phenotype in human monocytes is mediated by TGF-β signalling. Future studies are warranted to explore the intracellular pathways involved and to assess the clinical significance of urate-TGF-β relation.

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.

Melanoma Molecular Subtypes and Development of Prognostic and Immunotherapy-Related Genetic Characteristics by Ferroptosis Gene Analysis

The dissimilarity is a major problem in clinical therapy of skin cutaneous melanoma (SKCM). Objective and reproducible classification systems may help decode SKCM heterogeneity. ConsensusClusterPlus was used to establish a stable immune molecular classification based on ferroptosis-related genes that had been acquired from FerrDb. Moreover, the prognosis, somatic mutations, immune microenvironment characteristics, functional enrichment, and clinical responsiveness to the immune checkpoint blockade of different subtypes in two independent melanin datasets were compared. Kaplan-Meier curves, univariate, multivariate, least absolute contraction, and selection operator (LASSO) Cox regression analysis were used to develop a molecular model for predicting survival, which was verified by a nomogram on the basis of independent prognostic indicators. Two molecular subtypes (C1 and C2) for SKCM were first identified according to ferroptosis-related genes; C1 showed a poor prognosis, with lower infiltration degree of immune cells and TIED score and higher homologous recombination defects, fraction altered, the number of segments, and copy number amplification and deletion. These characteristics of C2 were the opposite of C1. A ferroptosis-related prognosis risk score (FPRS) model was constructed using 6 of 463 genes with differential expression between C1 and C2. This model splits patients into low- and high-risk cohorts. There were significant differences in the infiltration and proportion of immune cells, immune checkpoint gene expression, responsiveness to immune checkpoint therapy, and sensitivity to chemotherapeutic medications between low- and high-risk cohorts. This model was an independent prognostic marker for SKCM and has a high AUC. In summary, we have identified two subtypes of SKCM with different molecular and immune characteristics on the basis of ferroptosis-related genes and further developed and verified an FPRS model, which might independently serve as a prognostic marker for SKCM.

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.

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.

CLEC12B Decreases Melanoma Proliferation by Repressing Signal Transducer and Activator of Transcription 3

The potential role of CLEC12B, a gene predominantly expressed by skin melanocytes discovered through transcriptomic analysis, in melanoma is unknown. In this study, we show that CLEC12B expression is lower in melanoma and melanoma metastases than in melanocytes and benign melanocytic lesions and that its decrease correlates with poor prognosis. We further show that CLEC12B recruits SHP2 phosphatase through its immunoreceptor tyrosine-based inhibition motif domain, inactivates signal transducer and activator of transcription 1/3/5, increases p53/p21/p27 expression/activity, and modulates melanoma cell proliferation. The growth of human melanoma cells overexpressing CLEC12B in nude mice after subcutaneous injection is significantly decreased compared with that in the vehicle control group and is associated with decreased signal transducer and activator of transcription 3 phosphorylation and increased p53 levels in the tumors. Reducing the level of CLEC12B had the opposite effect. We show that CLEC12B represses the activation of the signal transducer and activator of transcription pathway and negatively regulates the cell cycle, providing a proliferative asset to melanoma cells.

Leukemia inhibitory factor is involved in the pathogenesis of NSCLC through activation of the STAT3 signaling pathway

Leukemia inhibitory factor (LIF) is a tumor promoter in several cancer types. However, the role of LIF in non-small cell lung cancer (NSCLC) remains to be explored. The present study explored the hypothesis that LIF is important for NSCLC development by measuring LIF expression and its downstream signal transducer and activator of transcription 3 (STAT3) phosphorylation in tumor samples derived from patients with NSCLC. The association between LIF expression and clinical features was analyzed in two cancer subtypes. The effects of LIF on cell proliferation, migration and invasion were also evaluated in a NSCLC-derived cell line, A549. LIF mRNA and protein expression levels were significantly higher in tumor tissues compared with those in the corresponding adjacent and normal lung tissues. Regarding NSCLC subtypes, LIF expression was significantly higher in adenocarcinoma than in squamous cell carcinoma tissues. It was also found that phosphorylated-STAT3 levels were higher in tumor tissues compared with those in the corresponding adjacent and normal lung tissues, which was in agreement with the LIF expression levels in NSCLC tissues. Clinically, overexpression of LIF was positively correlated with aggressive tumor characteristics, including lymph node metastasis and advanced tumor stage. In A549 cells, LIF treatment enhanced cell proliferation, migration and invasion. LIF also increased STAT3 phosphorylation in A549 cells, and the STAT3 inhibitor Stattic decreased A549 cell migration and invasion following LIF stimulation. The present results demonstrate that LIF is overexpressed in NSCLC, and that LIF can promote NSCLC development through activation of the STAT3 signaling pathway. The present study indicates that LIF may serve as a potential prognostic marker for NSCLC.

Gene expression in cell lines from human ameloblastoma immortalized using hTERT and HPV16-E6/E7

OBJECTIVE

The aim of this study was to evaluate and compare alterations in gene expression using two distinct immortalization methods (hTERT and HPV16-E6/E7) in ameloblastoma cell lines.

MATERIALS AND METHODS

A primary cell culture derived from human ameloblastoma (AME-1) was established and immortalized by two different methods using a transfection processes to hTERT and HPV-E6/E7. The RNA-seq was used to verify which immortalization method had less influence on gene expression. It was performed in four steps: extraction and collection of mRNA, PCR amplification, comparison with the human reference genome, and analysis of differential expression. The genes with differentiated expression were identified and mapped.

RESULTS

RNA-seq revealed genetic alterations in ameloblastoma cell lines after the immortalization process, including increased expression of tumor genes like MYC, E2F1, BRAF, HRAS, and HTERT, and a decrease in tumor suppressor genes like P53, P21, and Rb.

CONCLUSIONS

It is possible to affirm that cell immortalization is not an inert method regarding gene regulation mechanisms and the hTERT method (AME-TERT) presented fewer changes in gene expression levels.

Melanoma Progression under Obesity: Focus on Adipokines

Simple Summary

Obesity is a rapidly growing public health problem and the reason for numerous diseases in the human body, including cancer. This article reviews the current knowledge of the effect of molecules secreted by adipose tissue-adipokines on melanoma progression. We also discuss the role of these factors as markers of incidence, metastasis, and melanoma patient survival. Understanding the functions of adipokines will lead to knowledge of whether and how obesity promotes melanoma growth.

Abstract

Obesity is a growing problem in the world and is one of the risk factors of various cancers. Among these cancers is melanoma, which accounts for the majority of skin tumor deaths. Current studies are looking for a correlation between obesity and melanoma. They suspect that a potential cause of its development is connected to the biology of adipokines, active molecules secreted by adipose tissue. Under physiological conditions, adipokines control many processes, including lipid and glucose homeostasis, insulin sensitivity, angiogenesis, and inflammations. However, when there is an increased amount of fat in the body, their secretion is dysregulated. This article reviews the current knowledge of the effect of adipokines on melanoma growth. This work focuses on the molecular pathways by which adipose tissue secreted molecules modify the angiogenesis, migration, invasion, proliferation, and death of melanoma cells. We also discuss the role of these factors as markers of incidence, metastasis, and melanoma patient survival. Understanding the functions of adipokines will lead to knowledge of whether and how obesity promotes melanoma growth. Further studies may contribute to the innovations of therapies and the use of adipokines as predictive and/or prognostic biomarkers.

Measurement of 45 cytokine, chemokine and growth factors in established cell culture supernatants and autologous serum from advanced melanoma patients

Melanoma is one of the most aggressive forms of human cancer and its incidence has significantly increased worldwide over the last decades. This neoplasia has been characterized by the release of a wide variety of soluble factors, which could stimulate tumor cell proliferation and survival in an autocrine and paracrine manner. Consequently, we sought to evaluate the pattern of soluble factors produced by pre-metastatic and metastatic melanoma established cultures, and to determine whether these factors can be detected in the autologous serum of malignant melanoma patients. Our results showed that both melanoma cultures had a common profile of 27 soluble factors mainly characterized by the high expression of VEGF-A, IL-6, MCP-1, IL-8, and SDF-1. In addition, when we compared supernatants, we observed significant differences in VEGF-A, BDNF, FGF-2, and NGF-β concentrations. As we found in melanoma cultures, serum samples also had their specific production pattern composed by 21 soluble factors. Surprisingly, PDGF-BB and EGF were only found in serum, whereas IL-2, IL-4, IL-8, IL31, FGF2, and GRO-α were only expressed in the supernatant. Significant differences in PDGF-BB, MIP-1β, HGF, PIGF-1, BDNF, EGF, Eotaxin, and IP-10 were also found after comparing autologous serum with healthy controls. According to this, no correlation was found between culture supernatants and autologous serum samples, which suggests that some factors may act locally, and others systemically. Nonetheless, after validation of our results in an independent cohort of patients, we concluded that PDGF-BB, VEGF-A, and IP-10 serum levels could be used to monitor different melanoma stages.

Role of TG2 and TGF-β1 in the pathogenesis of human breast cancer

The present study analyzed the role of transforming growth factor-β₁ (TGF-β₁) and tissue transglutaminase (TG2) in breast cancer, as well as their protein levels in MCF-7 cells treated with cisplatin. In addition, the present study investigated the effects of TG2 and TGF-β₁ in MCF-7 cells following TGF-β₁ and TG2 inhibition or TGF-β₁ induction. The protein levels of TG2 and TGF-β₁ in breast cancer tissues and in MCF-7 cells treated with cisplatin, TG2 and TGF-β₁ inhibitors or 10 ng/ml TGF-β₁ were analyzed by immunohistochemical staining, immunofluorescence and western blotting. The results revealed that the expression levels of TG2 and TGF-β₁ in breast cancer tissues were significantly higher compared with those in paracancerous tissues. The fluorescence intensity of TG2 and TGF-β₁ in MCF-7 cells treated with cisplatin was lower compared with that in untreated MCF-7 cells. Using bioinformatics analysis, the present study predicted that TGF-β₁ may be associated with TG2. In addition, the expression levels of TGF-β₁ and TG2 in MCF-7 cells treated with inhibitors of TGF-β₁ and TG2 were lower compared with those in untreated MCF-7 cells. By contrast, the expression levels of TGF-β₁ and TG2 in MCF-7 cells treated with TGF-β₁ were higher compared with those in untreated MCF-7 cells. Therefore, the present study demonstrated that TGF-β₁ and TG2 may serve an important role in breast cancer tissues and in MCF-7 cells. In addition, it was revealed that TG2 and TGF-β₁ may have a synergistic role in MCF-7 cells.

Role and Mechanism of LIF in Oral Squamous Cell Carcinoma Progression

Background: Metastasis is a severe problem in patients with oral squamous cell carcinoma (OSCC), which is the fifth most common cancer worldwide. Leukemia inhibitory factor (LIF) has been studied in different cancers, while the role of LIF in OSCC remains unclear. Methods: LIF expression was detected in 100 OSCC samples by immunohistochemistry. Effects of LIF on cell motility were evaluated in OSCC cell lines. High-throughput microarray analysis was also conducted. The correlation between LIF and the downstream effector was analyzed by real-time quantitative reverse transcription PCR. Results: Patients with OSCC who had lymph node metastasis or advanced cancer stages showed high LIF expression. OSCC patients with higher LIF expression, advanced stage, large tumor size, or lymph node metastasis had significantly shorter overall survival. LIF regulated cancer cell motilities through outside-in signaling. The inhibin beta A subunit (INHBA) gene was identified as a crucial downstream effector of LIF-promoted OSCC progression and restored migration and invasion abilities in LIF knockdown transfectants. Conclusion: LIF enhances regional lymphatic spread, thus leading to an advanced cancer stage. Regulation of LIF downstream molecules such as INHBA inhibits the invasion or migration ability of cancer cells. Thus, LIF can be a potential target in preventing cancer metastasis and spread.

Co-Expression of VEGF and IL-6 Family Cytokines is Associated with Decreased Survival in HER2 Negative Breast Cancer Patients: Subtype-Specific IL-6 Family Cytokine-Mediated VEGF Secretion

Breast cancer cell-response to inflammatory cytokines such as interleukin-6 (IL-6) and oncostatin M (OSM) may affect the course of clinical disease in a cancer subtype-dependent manner. Furthermore, vascular endothelial growth factor A (VEGF) secretion induced by IL-6 and OSM may also be subtype-dependent. Utilizing datasets from Oncomine, we show that poor survival of invasive ductal carcinoma (IDC) breast cancer patients is correlated with both high VEGF expression and high cytokine or cytokine receptor expression in tumors. Importantly, epidermal growth factor receptor-negative (HER2-), but not HER2-positive (HER2+), patient survival is significantly lower with high tumor co-expression of VEGF and OSM, OSMRβ, IL-6, or IL-6Rα compared to low co-expression. Furthermore, assessment of HER2- breast cancer cells in vitro identified unique signaling differences regulating cytokine-induced VEGF secretion. The levels of VEGF secretion were analyzed by ELISA with siRNAs for hypoxia inducible factor 1 α (HIF1α) and signal transducer and activator of transcription 3 (STAT3). Specifically, we found that estrogen receptor-negative (ER-) MDA-MB-231 cells respond only to OSM through STAT3 signaling, while ER+ T47D cells respond to both OSM and IL-6, though to IL-6 to a lesser extent. Additionally, in the ER+ T47D cells, OSM signals through both STAT3 and HIF1α. These results highlight that the survival of breast cancer patients with high co-expression of VEGF and IL-6 family cytokines is dependent on breast cancer subtype. Thus, the heterogeneity of human breast cancer in relation to IL-6 family cytokines and VEGF may have important implications in clinical treatment options, disease progression, and ultimately patient prognosis.

Ecotropic viral integration site 1 regulates the progression of acute myeloid leukemia via MS4A3-mediated TGFβ/EMT signaling pathway

Acute myeloid leukemia (AML) is a type of malignant tumor that is caused by malignant clone hematopoietic stem cells. The ecotropic viral integration site 1 (Evi1) is a zinc finger transcription factor, which is highly expressed in AML, and its expression level has been associated with poor prognosis of AML. Previous studies have indicated that Evi1 may regulate cell proliferation, differentiation and apoptosis by inhibiting the membrane-spanning-4-domains subfamily-A member-3 (MS4A3) gene in AML. The aim of the present study was to investigate the role of Evi1 in the progression of AML. The results revealed that Evi1 was overexpressed in leukemia cells compared with normal T lymphocytes. MicroRNAs (miR)-133 and -431 that target Evi1 were investigated, and it was observed that there was a low expression of miR-431 in AML. The transfection of miR-431 was able to decrease the promoter methylation levels of the Evi1 gene in AML cells. The transfection of miR-431 also suppressed the migration and invasion of AML cells. The present study revealed that the transfection of miR-431 mimic was able to downregulate MS4A3 expression in AML cells. Furthermore, the expression levels of transforming growth factor β (TGFβ) and epithelial-to-mesenchymal transition (EMT) markers fibronectin, α-smooth muscle actin, and vimentin were downregulated following the transfection of miR-431 in AML cells. The overexpression of MS4A3 was also able to suppress miR-431-mediated inhibition of the expression of TGFβ and EMT markers in AML cells. The addition of TGFβ inhibited the downregulation of EMT markers by transfection of miR-431 in AML cells. The transfection of miR-431 suppressed the migration and invasion of AML cells, which was also abolished by the addition of TGFβ. In conclusion, the results of the present study indicated that Evi1 may be a potential molecular target of leukemia therapy via MS4A3-mediated TGFβ/EMT signaling pathway.

OSM potentiates preintravasation events, increases CTC counts, and promotes breast cancer metastasis to the lung

Background

Systemic and chronic inflammatory conditions in patients with breast cancer have been associated with reduced patient survival and increased breast cancer aggressiveness. This paper characterizes the role of an inflammatory cytokine, oncostatin M (OSM), in the preintravasation aspects of breast cancer metastasis.

Methods

OSM expression levels in human breast cancer tissue samples were assessed using tissue microarrays, and expression patterns based on clinical stage were assessed. To determine the in vivo role of OSM in breast cancer metastasis to the lung, we used three orthotopic breast cancer mouse models, including a syngeneic 4T1.2 mouse mammary cancer model, the MDA-MB-231 human breast cancer xenograft model, and an OSM-knockout (OSM-KO) mouse model. Progression of metastatic disease was tracked by magnetic resonance imaging and bioluminescence imaging. Endpoint analysis included circulating tumor cell (CTC) counts, lung metastatic burden analysis by qPCR, and ex vivo bioluminescence imaging.

Results

Using tissue microarrays, we found that tumor cell OSM was expressed at the highest levels in ductal carcinoma in situ. This finding suggests that OSM may function during the earlier steps of breast cancer metastasis. In mice bearing MDA-MB-231-Luc2 xenograft tumors, peritumoral injection of recombinant human OSM not only increased metastases to the lung and decreased survival but also increased CTC numbers. To our knowledge, this is the first time that a gp130 family inflammatory cytokine has been shown to directly affect CTC numbers. Using a 4T1.2 syngeneic mouse model of breast cancer, we found that mice bearing 4T1.2-shOSM tumors with knocked down tumor expression of OSM had reduced CTCs, decreased lung metastatic burden, and increased survival compared with mice bearing control tumors. CTC numbers were further reduced in OSM-KO mice bearing the same tumors, demonstrating the importance of both paracrine- and autocrine-produced OSM in this process. In vitro studies further supported the hypothesis that OSM promotes preintravasation aspects of cancer metastasis, because OSM induced both 4T1.2 tumor cell detachment and migration.

Conclusions

Collectively, our findings suggest that OSM plays a crucial role in the early steps of metastatic breast cancer progression, resulting in increased CTCs and lung metastases as well as reduced survival. Therefore, early therapeutic inhibition of OSM in patients with breast cancer may prevent breast cancer metastasis.

Electronic supplementary material

The online version of this article (10.1186/s13058-018-0971-5) contains supplementary material, which is available to authorized users.

An androgen-regulated miR-2909 modulates TGFβ signalling through AR/miR-2909 axis in prostate cancer

In recent years, microRNAs (miRNAs) have emerged as promising biomarkers for PCa diagnosis and prognosis. miR-2909 is a novel miRNA that can regulate immunogenomics and oncogenomics. The present study investigated the role of miR-2909 in the pathogenesis of PCa and the potential signalling pathways through which it operates. We have identified miR-2909 as a novel mediator of androgen/androgen receptor (AR) signalling that enhances the proliferation potential of PCa cells and assists in cancer survival under reduced androgen levels. Our results revealed that miR-2909 down regulates TGFBR2 by targeting its 3'-UTR sequence. We also observed that miR-2909 over-expression attenuated TGFβ-mediated SMAD3 activation, cell growth inhibition and apoptosis. Moreover, miR-2909 modulated the expression of p21CIP, c-MYC and CCND1 through TGFβ signalling. Importantly, we also demonstrated that miR-2909 and AR regulates each other's expression resulting in a positive feedback loop. In conclusion, our study suggests that miR-2909 is an androgen-inducible miRNA that exerts its oncogenic effects by attenuating the tumor-suppressive effects of TGFβ signalling.

Leukemia inhibitory factor promotes tumor growth and metastasis in human osteosarcoma via activating STAT3

The leukemia inhibitory factor (LIF) has been demonstrated to be an oncogene and participated in multiple procedures during the initiation and progression of many human malignancies. However, the role of LIF in osteosarcoma is still largely unknown. Here, we performed a series of in vitro and in vivo experiments to investigate the expression and biological functions of LIF in osteosarcoma. Compared to that in the non-cancerous tissues, LIF was significantly overexpressed in a panel of 68 osteosarcoma samples (p < 0.0001). Moreover, the overexpression of LIF was significantly correlated with advanced tumor stage, larger tumor size, and shorter overall survival. In addition, knockdown of LIF notably suppressed the proliferation and invasion of osteosarcoma via blocking the STAT3 signal pathway; in contrast, treatment with the recombinant LIF protein significantly promoted the growth and invasion of osteosarcoma through enhancing the phosphorylation of STAT3, which can be partially neutralized by the STAT3 inhibitor, HO-3867. In conclusion, we demonstrated that LIF was frequently overexpressed in osteosarcoma, which could promote the growth and invasion through activating the STAT3 pathway. Our findings proposed that LIF might be a potent therapeutic target for osteosarcoma.