Suppression of SCARA5 by Snail1 is essential for EMT-associated cell migration of A549 cells

The Role of SCARA5 as a Potential Biomarker in Squamous Cell Carcinoma of the Lung

Lung cancer is the leading cause of cancer-related deaths in the western world. Squamous cell carcinoma is one of the most common histological subtypes of this malignancy. For squamous cell carcinoma of the lung (LSCC), prognostic and predictive markers still are largely missing. In a previous study, we were able to show that the expression of THSD7A shows an association with unfavorable prognostic parameters in prostate cancer. There is also a link to a high expression of FAK. There is incidence that SCARA5 might be the downstream gene of THSD7A. Furthermore, there is evidence that SCARA5 interacts with FAK. We were interested in the role of SCARA5 as a potential biomarker in LSCC. Furthermore, we wanted to know whether SCARA5 expression is linked to THSD7A positivity and to the expression level of FAK. For this reason, we analyzed 101 LSCC tumors by immunohistochemistry. Tissue microarrays were utilized. No significant association was found between SCARA5 expression and overall survival or clinicopathological parameters. There was also no significant association between THSD7A positivity and SCARA5 expression level. Moreover, no significant association was found between FAK expression level and SCARA5 expression level. SCARA5 seems not to play a major role as a biomarker in squamous cell carcinoma of the lung.

Paeonol upregulates expression of tumor suppressors TNNC1 and SCARA5, exerting anti-tumor activity in non-small cell lung cancer cells

Paeonol, a naturally bioactive phenolic ingredient predominantly isolated from Paeonia suffruticosa, has recently garnered significant interest as an anti-tumor agent against diverse carcinomas including non-small cell lung cancer (NSCLC). However, the anti-tumor mechanism of paeonol in NSCLC remains unclear. Cell viability, caspase-3 activity, and apoptosis were evaluated using CCK-8 assay, Caspase-3 Colorimetric Assay Kit, and flow cytometry analysis, respectively. GSE186218 was downloaded from NCBI Gene Expression Omnibus (GEO). The common genes were screened using GEO2R and Draw Venn Diagram software. Expression of troponin C type 1 (TNNC1), scavenger receptor class A member 5 (SCARA5), phosphorylated protein kinase B (AKT) (p-AKT) and AKT was examined using GEPIA database, qRT-PCR and western blot analysis. Paeonol treatment concentration-dependently inhibited cell viability and increased caspase-3 activity and apoptotic rate in NSCLC cells. Only 5 overlapping genes including TNNC1 and SCARA5 were obtained among 232 upregulated genes in GSE186218, 200 underexpressed genes in TCGA-LUAD, and 200 underexpressed genes in TCGA-LUSC according to the Venn diagram software. TNNC1 and SCARA5, two known tumor suppressors, were significantly downregulated in LUAD and LUSC tissues and NSCLC cells. Paeonol dose-dependently upregulated TNNC1 and SCARA5 expression in NSCLC cells. Paeonol suppressed the AKT pathway by upregulating TNNC1 and SCARA5 expression. AKT inhibitor attenuated the effects of TNNC1 or SCARA5 knockdown on the anti-tumor activity of paeonol. In conclusion, paeonol exhibited anti-cancer activity in NSCLC cells through inactivating the AKT pathway by upregulating TNNC1 or SCARA5.

miRNAs in pancreatic cancer progression and metastasis

Small non-coding RNA or microRNA (miRNA) are critical regulators of eukaryotic cells. Dysregulation of miRNA expression and function has been linked to a variety of diseases including cancer. They play a complex role in cancers, having both tumour suppressor and promoter properties. In addition, a single miRNA can be involved in regulating several mRNAs or many miRNAs can regulate a single mRNA, therefore assessing these roles is essential to a better understanding in cancer initiation and development. Pancreatic cancer is a leading cause of cancer death worldwide, in part due to the lack of diagnostic tools and limited treatment options. The most common form of pancreatic cancer, pancreatic ductal adenocarcinoma (PDAC), is characterised by major genetic mutations that drive cancer initiation and progression. The regulation or interaction of miRNAs with these cancer driving mutations suggests a strong link between the two. Understanding this link between miRNA and PDAC progression may give rise to novel treatments or diagnostic tools. This review summarises the role of miRNAs in PDAC, the downstream signalling pathways that they play a role in, how these are being used and studied as therapeutic targets as well as prognostic/diagnostic tools to improve the clinical outcome of PDAC.

Single-cell Transcriptomic Analysis Reveals an Immunosuppressive Network Between POSTN CAFs and ACKR1 ECs in TKI-resistant Lung Cancer

BACKGROUND/AIM

Tyrosine kinase inhibitor (TKI) therapy, a principal treatment for advanced non-small cell lung cancer (NSCLC), frequently encounters the development of drug resistance. The tumor microenvironment (TME) plays a critical role in the progression of NSCLC, yet the relationship between endothelial cells (ECs) and cancer-associated fibroblasts (CAFs) subpopulations in TKI treatment resistance remains largely unexplored.

MATERIALS AND METHODS

The BioProject database PRJNA591860 project was used to analyze scRNA-seq data including 49 advanced-stage NSCLC samples across three different time points: pre-targeted therapy (naïve), post-partial response (PR) to targeted therapy, and post-progressive disease (PD) stage. The data involved clustering stromal cells into multiple CAFs and ECs subpopulations. The abundance changes and functions of each cluster during TKI treatment were investigated by KEGG and GO analysis. Additionally, we identified specific transcription factors and metabolic pathways via DoRothEA and scMetabolism. Moreover, cell-cell communications between PD and PR stages were compared by CellChat.

RESULTS

ECs and CAFs were clustered and annotated using 49 scRNA-seq samples. We identified seven ECs subpopulations, with OIT3 ECs showing enrichment in the PR phase with a drug-resistance phenotype, and ACKR1 ECs being prevalent in the PD phase with enhanced cell adhesion. Similarly, CAFs were clustered into 7 subpopulations. PLA2G2A CAFs were predominant in PR, whereas POSTN CAFs were prevalent in PD, characterized by an immunomodulatory phenotype and increased collagen secretion. CellChat analysis showed that ACKR1 ECs strongly interacted with macrophage through the CD39 pathway and POSTN CAFs secreted Tenascin-C (TNC) to promote the progression of epithelial cells, primarily malignant ones, in PD.

CONCLUSION

This study reveals that POSTN CAFs and ACKR1 ECs are associated with resistance to TKI treatment, based on single-cell sequencing.

SCARA5 as a downstream factor of PCAT29, inhibits proliferation, migration, and invasion of bladder cancer

Scavenger receptor class A, member 5 (SCARA5) has been identified a novel tumor suppressor in several cancers. However, the functional and underlying mechanism of SCARA5 in bladder cancer (BC) need investigation. Here, we found SCARA5 expression was downregulated in both BC tissues and cell lines. Low SCARA5 in BC tissues was associated with a shorter overall survival. Moreover, SCARA5 overexpression reduced BC cell viability, colony formation, invasion, and migration. Further investigation demonstrated that the expression of SCARA5 was negatively regulated by miR-141. Furthermore, the long non-coding RNA prostate cancer associated transcript 29 (PCAT29) inhibited the proliferation, invasion, and migration of BC cells by sponging miR-141. Luciferase activity assays revealed that PCAT29 targeted miR-141 and miR-141 targeted SCARA5. In conclusion, SCARA5, as a downstream factor of the PCAT29/miR-141 axis, inhibited the proliferation, migration, and invasion of BC cells. These findings provide novel insights into the detailed molecular mechanisms of BC development.

SCARA5 Is Overexpressed in Prostate Cancer and Linked to Poor Prognosis

Prostate cancer is one of the most common malignancies worldwide, showing a wide range of clinical behaviors. Therefore, several treatment options arise out of the diagnosis "prostate cancer". For this reason, it is desirable to find novel prognostic and predictive markers. In former studies, we showed that THSD7A expression is associated with unfavorable prognostic parameters in prostate cancer and is linked to a high expression of focal adhesion kinase (FAK). Recently, scavenger receptor class A member 5 (SCARA5) was reported to be the downstream gene of THSD7A in esophageal squamous cell carcinoma. SCARA5 is believed to play an important role in the development and progression of several different tumor types. Most studies describe SCARA5 as a tumor suppressor. There is also evidence that SCARA 5 interacts with FAK. To examine the role of SCARA5 as a potential biomarker in prostate cancer, a total of 461 prostate cancers were analyzed via immunohistochemistry using tissue microarrays. Furthermore, we compared the expression level of SCARA5 with our previously collected data on THSD7A and FAK. High SCARA5 expression was associated with advanced tumor stage (p < 0.001), positive nodal status (p < 0.001) and high Gleason-score (p < 0.001). At least, strongly SCARA5-positive cancers were associated with THSD7A-positivity. There was no significant association between SCARA5 expression level and FAK expression level. To our knowledge, we are the first to investigate the role of SCARA5 in prostate cancer and we demonstrated that SCARA5 might be a potential biomarker in prostate cancer.

Methylated tumor suppressor gene SCARA5 inhibits the proliferation, migration and invasion of nasopharyngeal carcinoma

Background: SCARA5 may play an important role in nasopharyngeal carcinoma. Materials & methods: PCR and immunohistochemistry were used to detect the expression and promoter methylation of SCARA5. Cell proliferation assays, spheroid culture, flow cytometry analysis, Transwell assays and xenotransplantation tests were utilized to determine the functional effects of SCARA5. RNA-sequencing, western blotting, immunofluorescence and dual-luciferase reporter assays were used to assess SCARA5-mediated outcomes. Results: SCARA5 was downregulated by promoter methylation. Overexpression of SCARA5 inhibited cell migration, invasion and proliferation. SCARA5 enhanced nasopharyngeal carcinoma cell sensitivity to chemotherapy with cisplatin and 5-fluorouracil. SCARA5 drives tumor apoptosis by downregulating HSPA2. Conclusion: SCARA5 may be a useful clinical marker in nasopharyngeal carcinoma.

SCARA5 inhibits oral squamous cell carcinoma via inactivating the STAT3 and PI3K/AKT signaling pathways

Oral squamous cell carcinoma (OSCC) is a common tumor in the world. Despite the rapid development of medical care, OSCC is also accompanied by high incidence and mortality every year. Therefore, it is still necessary to continuously develop new methods or find new targets to treat OSCC. Previous research showed that scavenger receptor class A member 5 (SCARA5) was one of the potential biomarkers of OSCC, and its expression is significantly low in OSCC. This study aimed to explore the role and related molecular mechanisms of SCARA5 in OSCC. In this study, we found that the SCARA5 expression was lower in CAL-27 and SCC-9 cells than that in human normal oral epithelial keratinocytes. SCARA5 overexpression significantly inhibited cell proliferation and induced apoptosis of CAL-27 and SCC-9 cells. In addition, SCARA5 repressed OSCC cell epithelial-mesenchymal transformation (EMT), evidenced by increased E-cadherin expression and reduced N-cadherin expression. Finally, we found that SCARA5 could suppress STAT3, PI3K, and AKT phosphorylation. Therefore, SCARA5 was related to STAT3 and PI3K/AKT signaling pathways in OSCC. In conclusion, SCARA5 inhibited the proliferation and EMT and induced the apoptosis of OSCC cells through the inhibition of STAT3 and PI3K/AKT signaling pathways, thereby exerting a tumor suppressor effect.

SCARA5 induced ferroptosis to effect ESCC proliferation and metastasis by combining with Ferritin light chain

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) remains one of the most lethal cancers worldwide accompany with an extremely poor prognosis. Therefore, this study aims to screen for new molecules affecting ESCC and explore their mechanisms of action to provide ideas for targeted therapies for ESCC.

METHODS

Firstly, we screened out the membrane protein SCARA5 by high-throughput sequencing of the ESCC patient tissues, and RT-qPCR and WB were used to verify the differential expression of SCARA5 in esophageal cell lines, and IHC analyzed the expression localization of SCARA5 in ESCC tissue. Then, flow cytometry, wound healing assay, Transwell assay and CCK-8 assay were used to explore the effects of SCARA5 on cell cycle, migration and invasion as well as cell proliferation activity of esophageal squamous carcinoma cells. Meanwhile, transmission electron microscopy was used to detect changes in cellular mitochondrial morphology, and flow cytometry were used to detect changes in intracellular reactive oxygen metabolism, and immunofluorescence and flow cytometry were used to detect changes in intracellular Fe2+. Mechanistically, co-immunoprecipitation was used to detect whether SCARA5 binds to ferritin light chain, and ferroptosis-related protein expression was detected by WB. Finally, the tumor xenograft model was applied to validation the role of SCARA5 tumor growth inhibition in vivo.

RESULTS

We found that SCARA5 was aberrantly decreased in ESCC tissues and cell lines. Furthermore, we confirmed that SCARA5 suppressed the cell cycle, metastasis and invasion of ESCC cells. Meanwhile, we also found that overexpression of SCARA5 caused changes in mitochondrial morphology, accumulation of intracellular reactive oxygen species and increased intracellular Fe2+ in ESCC cells, which induced ferroptosis in ESCC cells. Mechanically, we validated that SCARA5 combined with ferritin light chain and increased intracellular Fe2+. As well as, overexpression SCARA5 induced ferroptosis by increasing ferritin light chain in nude mice subcutaneous tumors and inhibited the growth of nude mice subcutaneous tumors.

CONCLUSION

Collectively, our findings demonstrated that SCARA5 suppressed the proliferation and metastasis of ESCC by triggering ferroptosis through combining with ferritin light chain.

Highly Expressing SCARA5 Promotes Proliferation and Migration of Esophageal Squamous Cell Carcinoma

Background

Thrombospondin type 1 domain-containing 7A (THSD7A) was reported to play a procancer role in esophageal squamous cell carcinoma (ESCC). The aim of the study was to screen the downstream functional genes of THSD7A and explore their functions in ESCC, based on the reported research into THSD7A function and on gene microarrays.

Methods

We adopted quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and Celigo high-content screening (HCS) technology to screen the downstream genes of THSD7A. The expression level of target genes was examined by PCR, western blot, and immunohistochemistry (IHC). The effects of these target genes on ESCC malignant biological behavior were performed in vivo and in vitro. The Kaplan-Meier (K-M) survival analysis and Cox regression were used to analyze the prognostic significance of target genes in ESCC patients. Experiments in the literature on liver cancer (LC) were repeated to verify the functions of these genes in different tumors. We further explored the cancer-promoting mechanism of target genes in ESCC by sequencing of the genes' exons.

Results

Scavenger receptor class A member 5 (SCARA5) was proved to be the downstream driving gene of THSD7A. SCARA5 promoted cell proliferation and migration but inhibited apoptosis in ESCC. IHC results confirmed that SCARA5 expression in ESCC exceeded that in normal tissues. The K-M survival analysis indicated that SCARA5 expression quantity was not related to prognosis, but tumor volume and T classification were both the independent prognostic factors. Repetition of experiments in LC in the literature confirmed that SCARA5 had exactly opposite functions in EC and LC.

Conclusion

SCARA5 was related to the development and occurrence of ESCC. Our findings suggested that it was a potentially diagnostic individualized therapeutic target for ESCC in the future and that its application could possibly be combined with that of upstream THSD7A gene.

Production of Recombinant Active Human TGFβ1 in Nicotiana benthamiana

The production of recombinant proteins in plant systems is receiving wider attention. Indeed, various plant-produced pharmaceuticals have been shown to be biologically active. However, the production of human growth factors and cytokines in heterologous systems is still challenging because they often act as complex forms, such as homo- or hetero-dimers, and their production is tightly regulated in vivo. In this study, we demonstrated that the mature form of human TGFβ1 produced and purified from Nicotiana benthamiana shows biological activity in animal cells. To produce the mature form of TGFβ1, various recombinant genes containing the mature form of TGFβ1 were generated and produced in N. benthamiana. Of these, a recombinant construct, BiP:M:CBM3:LAP[C33S]:EK:TGFβ1, was expressed at a high level in N. benthamiana. Recombinant proteins were one-step purified using cellulose-binding module 3 (CBM3) as an affinity tag and microcrystalline cellulose (MCC) beads as a matrix. The TGFβ1 recombinant protein bound on MCC beads was proteolytically processed with enterokinase to separate mature TGFβ1. The mature TGFβ1 still associated with Latency Associated Protein, [LAP(C33S)] that had been immobilized on MCC beads was released by HCl treatment. Purified TGFβ1 activated TGFβ1-mediated signaling in the A549 cell line, thereby inducing phosphorylation of SMAD-2, the expression of ZEB-2 and SNAIL1, and the formation of a filopodia-like structure. Based on these results, we propose that active mature TGFβ1, one of the most challenging growth factors to produce in heterologous systems, can be produced from plants at a high degree of purity via a few steps.

SCARA3 inhibits cell proliferation and EMT through AKT signaling pathway in lung cancer

BACKGROUND

Scavenger receptor class A member 3 (SCARA3) is decreased in prostate cancer and myeloma. However, functions of SCARA3 in various cancers remain unclear. In this study, we tried to evaluate the functional study of SCARA3 in lung cancer.

METHODS

The expression level of SCARA3 in the TCGA-database, lung cancer tissue microarray and lung cancer cells and the prognosis of lung cancer patients were measured. Lung cancer tissue microarray was analyzed pathologically using immunohistochemistry, and quantitative analysis of SCARA3 in normal lung cells and lung cancer cells was analyzed using western blot analysis. Survival curves for lung cancer patients were prepared with the Kaplan-Meier method. Migration and invasion of SCARA3 overexpressed lung cancer cells were determined using a Transwell chamber system. Proliferation of lung cancer cells was determined based on cell viability assay using cell culture in vitro and a tumorigenicity model of BALB/C nude mouse in vivo.

RESULTS

The expression of SCARA3 was abnormally reduced in TCGA-database, lung tissue microarray, and various lung cancer cells. However, overexpression of SCARA3 reduced the proliferation of lung cancer. The ability of SCARA3 to inhibit cancer cell proliferation was maintained even in vivo using a mouse xenograft model. In addition, overexpression of SCARA3 reduced migration and invasion ability of lung cancer cells and induced decreases of EMT markers such as β-catenin, vimentin, and MMP9. We aimed to prove the role of SCARA3 in the treatment of Lung cancer, and shown that the expression level of SCARA3 is important in cancer treatment using cisplatin. The enhancement of the effect of cisplatin according to SCARA3 overexpression is via the AKT and JNK pathways.

CONCLUSIONS

This study confirmed an abnormal decrease in SCARA3 in lung cancer. Overexpression of SCARA3 potently inhibited tumors in lung cancer and induced apoptosis by increasing sensitivity of lung cancer to cisplatin. These results suggest that SCARA3 is a major biomarker of lung cancer and that the induction of SCARA3 overexpression can indicate an effective treatment.

New Proteins Contributing to Immune Cell Infiltration and Pannus Formation of Synovial Membrane from Arthritis Diseases

An inflamed synovial membrane plays a major role in joint destruction and is characterized by immune cells infiltration and fibroblast proliferation. This proteomic study considers the inflammatory process at the molecular level by analyzing synovial biopsies presenting a histological inflammatory continuum throughout different arthritis joint diseases. Knee synovial biopsies were obtained from osteoarthritis (OA; n = 9), chronic pyrophosphate arthropathy (CPPA; n = 7) or rheumatoid arthritis (RA; n = 8) patients. The histological inflammatory score was determined using a semi-quantitative scale based on synovial hyperplasia, lymphocytes, plasmocytes, neutrophils and macrophages infiltration. Proteomic analysis was performed by liquid chromatography-mass spectrometry (LC-MS/MS). Differentially expressed proteins were confirmed by immunohistochemistry. Out of the 1871 proteins identified and quantified by LC-MS/MS, 10 proteins (LAP3, MANF, LCP1, CTSZ, PTPRC, DNAJB11, EML4, SCARA5, EIF3K, C1orf123) were differentially expressed in the synovial membrane of at least one of the three disease groups (RA, OA and CPPA). Significant increased expression of the seven first proteins was detected in RA and correlated to the histological inflammatory score. Proteomics is therefore a powerful tool that provides a molecular pattern to the classical histology usually applied for synovitis characterization. Except for LCP1, CTSZ and PTPRC, all proteins have never been described in human synovitis.

Clinicopathological and Prognostic Features of 67 Cases with Pulmonary Sarcomatoid Carcinoma: An 18-Year Single-Centre Experience

INTRODUCTION

Pulmonary sarcomatoid carcinoma (PSC) is a very rare subtype of non-small-cell lung cancer (NSCLC). It is frequently diagnosed in the advanced stage and is resistant to conventional chemotherapeutics. Due to the unique nature and rarity, we evaluated the epidemiological, clinicopathological, and survival data of PSC patients treated at our centre.

PATIENTS AND METHODS

We retrospectively collected demographic and clinical data of 67 PSC patients from a single tertiary referral hospital, between the 2000 and 2018. Univariate and multivariate analyses were performed to determine the risk factors affecting survival.

RESULTS

The median age was 61 years, and the percentage of male was 74.6%. Most of the patients had a smoking history (76.9%). The most common PSC subtype was pleomorphic carcinoma (46.3%). The median overall survival (OS) was 55.4 months, and the 5-year OS rate was 47.5%. Advanced stage, T4 tumour, and positive lymph node involvement were associated with poor OS (p < 0.05). The patients with negative epithelial markers had poorer prognosis (p = 0.027) and had more frequently stage IV disease (p = 0.016). Surgical treatment and stage IV disease were determined to be independent prognostic factors.

CONCLUSION

PSC is an extremely rare and aggressive variant of NSCLC. Positive epithelial markers may have favourable prognostic significance in PSC. Resection of the tumour with a negative surgical margin is crucial for better survival. The prognosis of the disease is very poor in the metastatic stage.

Tumor suppressive effect of scavenger receptor class A member 5 overexpression in colorectal cancer by regulating PI3K/AKT/mTOR pathway

Background

Colorectal cancer (CRC) exhibits high risks of morbidity and mortality.

Objective

To investigate the effect of scavenger receptor class A member 5 (SCRAR5) on CRC and its mechanism on modulation of cancer development.

Methods

The SCRAR5 expression in four kinds of CRC cell lines (SW620, SW480, HT29, and HCT116) was measured by quantitative PCR and western blotting, respectively. The effects of SCRAR5 abnormal expression on cell proliferation, apoptosis, and migration were analyzed by CCK-8 assay, EdU assay, colony-forming assay, flow cytometry assay, Transwell assay and wound healing assay, respectively. Meanwhile, the involvements of PI3K/AKT/mTOR pathway with the role of SCRAR5 were investigated by western blotting. Afterwards, the in vivo effects of SCRAR5 abnormal expression on CRC xenograft mice were finally investigated by evaluating tumor volume, apoptosis and Ki67 expression.

Results

SCRAR5 was lowly expressed in CRC cell lines, especially SW480 cells. Up-regulation of SCRAR5 significantly promoted cell apoptosis, reduced cell proliferation and migration in SW480 cells. Notably, SCRAR5 overexpression obviously inhibited the phosphorylation levels of PI3K, AKT, and mTOR. Reversely, SCRAR5 silence exhibited promoting effects on HT29 cells. Consistently, in vivo experiments also revealed that SCRAR5 overexpression remarkably suppressed tumor volume and Ki67 expression, as well as promoted cell apoptosis.

Conclusions

Overall, up-regulating of SCRAR5 obviously inhibited CRC tumor growth in vitro and in vivo, which might be related to PI3K/AKT/mTOR pathway.

WITHDRAWN: SCARA5 regulated by MEG3/miR-141 axis attenuates proliferation, migration and invasion of bladder cancer

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SCARA5 inhibits gastric cancer progression via epithelial-mesenchymal transition suppression

Scavenger receptor class A member 5 (SCARA5) has been reported to be implicated in several types of cancer. However, its biological roles and mechanism of SCARA5 in gastric cancer (GC) have not been elucidated. In the present study, SCARA5 expression was found to be downregulated in GC which was associated with promoter methylation. The protein level of SCARA5 was negatively associated with aggressive clinicopathological characteristics, as well as poor prognosis. Moreover, SCARA5 overexpression markedly suppressed the growth, migration and invasion of GC cell lines in vitro. Furthermore, upregulation of SCARA5 inhibited gastric tumor growth and metastasis in a xenograft model. Mechanistic analysis revealed that SCARA5 suppressed the migration and invasion of GC cells via inhibiting epithelial-mesenchymal transition (EMT) and inactivating MMP-2 and MMP-9. Taken together, these results demonstrated that SCARA5 might play vital roles in the GC genesis and progression and could serve as a potential biomarker for diagnosis and therapeutic target of GC.

SCARA5 suppresses the proliferation and migration, and promotes the apoptosis of human retinoblastoma cells by inhibiting the PI3K/AKT pathway

Retinoblastoma (RB) is the most common ocular malignancy that occurs during childhood. Scavenger receptor class A member 5 (SCARA5) is considered to function as an anti-oncogene in several types of malignant tumor. The present study investigated the functional role and underlying mechanism of SCARA5 in human RB cells. Reverse transcription-quantitative PCR and western blotting were used to detect the relative expression levels of SCARA5 in four human RB cell lines. In addition, transfection was performed to either knockdown or induce overexpression of SCARA5 in human RB Y79 cells. The proliferation, migration and apoptosis of RB cells was then measured by Cell Counting Kit 8 assay, 5-ethynyl-2′-deoxyuridine assay, clone formation assay, Transwell assay, Hoechst staining and TUNEL staining, respectively. Western blotting was performed to detect changes in the expression levels of key proteins involved in the PI3K/AKT and apoptotic pathways. The present study revealed that SCARA5 was expressed at lower levels in four tumorigenic human RB cell lines compared with in a human retinal pigment non-tumorigenic cell line. Functional analysis demonstrated that overexpression of SCARA5 decreased the proliferation and migration, and promoted the apoptosis of human RB cells in vitro, whereas in vivo experiments revealed a decrease in RB progression following SCARA5 overexpression. In addition, overexpression of SCARA5 inhibited phosphorylated (p)-PI3K and p-AKT expression, and knockdown of SCARA5 increased p-PI3K and p-AKT expression; however, no changes in total PI3K and AKT expression were observed. Bcl-2 exhibited similar changes in expression to those displayed by p-PI3K and p-AKT, whereas Bax and cleaved caspase-3 exhibited trends in expression that were the opposite to those shown by p-PI3K and p-AKT. In conclusion, the present results demonstrated that SCARA5 could inhibit the proliferation and promote the apoptosis of RB cell lines by suppressing the PI3K/AKT signaling pathway, thus suggesting a novel strategy for treating RB.

A prolonged exposure of human lung carcinoma epithelial cells to benzo[a]pyrene induces p21-dependent epithelial-to-mesenchymal transition (EMT)-like phenotype

Deciphering the role of the aryl hydrocarbon receptor (AhR) in lung cancer cells may help us to better understand the role of toxic AhR ligands in lung carcinogenesis, including cancer progression. We employed human lung carcinoma A549 cells to investigate their fate after continuous two-week exposure to model AhR agonists, genotoxic benzo[a]pyrene (BaP; 1 μM) and non-genotoxic 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; 10 nM). While TCDD increased proliferative rate of A549 cells, exposure to BaP decreased cell proliferation and induced epithelial-to-mesenchymal transition (EMT)-like phenotype, which was associated with enhanced cell migration, invasion, and altered cell morphology. Although TCDD also suppressed expression of E-cadherin and activated some genes linked to EMT, it did not induce the EMT-like phenotype. The results of transcriptomic analysis, and the opposite effects of BaP and TCDD on cell proliferation, indicated that a delay in cell cycle progression, together with a slight increase of senescence (when coupled with AhR activation), favors the induction of EMT-like phenotype. The shift towards EMT-like phenotype observed after simultaneous treatment with TCDD and mitomycin C (an inhibitor of cell proliferation) confirmed the hypothesis. Since BaP decreased cell proliferative rate via induction of p21 expression, we generated the A549 cell model with reduced p21 expression and exposed it to BaP for two weeks. The p21 knockdown suppressed the BaP-mediated EMT-like phenotype in A549 cells, thus confirming that a delayed cell cycle progression, together with p21-dependent induction of senescence-related chemokine CCL2, may contribute to induction of EMT-like cell phenotype in lung cells exposed to genotoxic AhR ligands.

Bovine scavenger receptor class A (SR-A) exhibit specific patterns of regulation in the endometrium during the oestrous cycle and early pregnancy

In mammals, tight regulation of maternal endometrial function is critical for pregnancy success. In bovine species, endometrial expression of members of the scavenger receptor class A (SR-A) has been listed in high-throughput analyses, but very little is known about the involvement of these immune factors during implantation in mammals. To provide first insights into the contribution of SR-A to endometrial physiology, we analysed the expression and regulation of all members of SR-A (SR-A1, SR-A3-SR-A6) during the oestrous cycle and early pregnancy in cattle. Levels of SR-A1 were increased on Day 20 of pregnancy, whereas SR-A3 levels were increased on Day 13 of the oestrous cycle and of the pregnancy. Although SR-A4 levels were reduced on Day 20 of the oestrous cycle, they remained high in pregnant animals. SR-A5 levels increased by Day 13 of the oestrous cycle and decreased on Day 20, but remained high in pregnant animals. Interferon-τ does not affect SR-A gene expression, whereas progesterone regulates the expression of the SR-A3 and SR-A5 transcripts. Endometrial SR-A3 appeared significantly higher in cows carrying invitro-produced embryos than in AI cows. Our data suggest that members of the SR-A family are involved in endometrial remodelling and regulation of endometrial gland physiology, both processes being critical for implantation in mammals.

Identification of SCARA5 Gene as a Potential Immune-Related Biomarker for Triple-Negative Breast Cancer by Integrated Analysis

Triple-negative breast cancer (TNBC) refers to breast cancer without significant expression of estrogen receptor (ER), progesterone receptor (PR), or human epidermal growth factor receptor 2. We sought to identify the hub genes and find the potential progression mechanism of TNBC as well as immunotherapeutic targets. First, we screened the overlapped hub genes of Immune and Stromal, and the tumor mutation burden gene sets, as well as the The Cancer Genome Atlas (TCGA)-TNBC data set. Among these hub genes, we performed gene set enrichment analysis (GSEA) and gene set variation analysis analyses to recognize and evaluate the hub genes. Moreover, immune cell infiltration was evaluated by the CIBERSORT algorithm and single-sample GSEA. In addition, the expression and methylation of scavenger receptor class A member 5 (SCARA5) in TNBC were verified by quantitative PCR and methylation-specific PCR. Also, MTT and transwell assays were used to assess the biological function of SCARA5 in TNBC. SCARA5 and CMA1 were listed, and they mainly participated in cancer-related signaling pathways and immune-related signaling pathways. Interestingly, SCARA5 was closely associated with tumor purity and immune cell infiltration. Moreover, we found that SCARA5 was significantly downregulated and hypermethylation was in the promoter of SCARA5 in TNBC tissues. Our study showed the role of SCARA5 in proliferation and migration of TNBC, and suggested that SCARA5 can potentially serve as a candidate immunotherapy target for TNBC.

The glutathione peroxidase 8 (GPX8)/IL-6/STAT3 axis is essential in maintaining an aggressive breast cancer phenotype

One of the emerging hallmarks of cancer illustrates the importance of metabolic reprogramming, necessary to synthesize the building blocks required to fulfill the high demands of rapidly proliferating cells. However, the proliferation-independent instructive role of metabolic enzymes in tumor plasticity is still unclear. Here, we provide evidence that glutathione peroxidase 8 (GPX8), a poorly characterized enzyme that resides in the endoplasmic reticulum, is an essential regulator of tumor aggressiveness. We found that GPX8 expression was induced by the epithelial-mesenchymal transition (EMT) program. Moreover, in breast cancer patients, GPX8 expression significantly correlated with known mesenchymal markers and poor prognosis. Strikingly, GPX8 knockout in mesenchymal-like cells (MDA-MB-231) resulted in an epithelial-like morphology, down-regulation of EMT characteristics, and loss of cancer stemness features. In addition, GPX8 knockout significantly delayed tumor initiation and decreased its growth rate in mice. We found that these GPX8 loss-dependent phenotypes were accompanied by the repression of crucial autocrine factors, in particular, interleukin-6 (IL-6). In these cells, IL-6 bound to the soluble receptor (sIL6R), stimulating the JAK/STAT3 signaling pathway by IL-6 trans-signaling mechanisms, so promoting cancer aggressiveness. We observed that in GPX8 knockout cells, this signaling mechanism was impaired as sIL6R failed to activate the JAK/STAT3 signaling pathway. Altogether, we present the GPX8/IL-6/STAT3 axis as a metabolic-inflammatory pathway that acts as a robust regulator of cancer cell aggressiveness.

Epigenetic Landscape in Pancreatic Ductal Adenocarcinoma: On the Way to Overcoming Drug Resistance?

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive solid malignancies due to the rapid rate of metastasis and high resistance to currently applied cancer therapies. The complex mechanism underlying the development and progression of PDAC includes interactions between genomic, epigenomic, and signaling pathway alterations. In this review, we summarize the current research findings on the deregulation of epigenetic mechanisms in PDAC and the influence of the epigenome on the dynamics of the gene expression changes underlying epithelial–mesenchymal transition (EMT), which is responsible for the invasive phenotype of cancer cells and, therefore, their metastatic potential. More importantly, we provide an overview of the studies that uncover potentially actionable pathways. These studies provide a scientific basis to test epigenetic drug efficacy in synergy with other anticancer therapies in future clinical trials, in order to reverse acquired therapy resistance. Thus, epigenomics has the potential to generate relevant new knowledge of both a biological and clinical impact. Moreover, the potential, hurdles, and challenges of predictive biomarker discoveries will be discussed, with a special focus on the promise of liquid biopsies.

Altered expression of fucosylation pathway genes is associated with poor prognosis and tumor metastasis in non‑small cell lung cancer

Fucosylation is a post‑translational modification that attaches fucose residues to protein‑ or lipid‑bound oligosaccharides. Certain fucosylation pathway genes are aberrantly expressed in several types of cancer, including non‑small cell lung cancer (NSCLC), and this aberrant expression is associated with poor prognosis in patients with cancer. However, the molecular mechanism by which these fucosylation pathway genes promote tumor progression has not been well‑characterized. The present study analyzed public microarray data obtained from NSCLC samples. Multivariate analysis revealed that altered expression of fucosylation pathway genes, including fucosyltransferase 1 (FUT1), FUT2, FUT3, FUT6, FUT8 and GDP‑L‑fucose synthase (TSTA3), correlated with poor survival in patients with NSCLC. Inhibition of FUTs by 2F‑peracetyl‑fucose (2F‑PAF) suppressed transforming growth factor β (TGFβ)‑mediated Smad3 phosphorylation and nuclear translocation in NSCLC cells. In addition, wound‑healing and Transwell migration assays demonstrated that 2F‑PAF inhibited TGFβ‑induced NSCLC cell migration and invasion. Furthermore, in vivo bioluminescence imaging analysis revealed that 2F‑PAF attenuated the metastatic capacity of NSCLC cells. These results may help characterize the oncogenic role of fucosylation in NSCLC biology and highlight its potential for developing cancer therapeutics.

Therapeutic effects of scavenger receptor MARCO ligand on silica-induced pulmonary fibrosis in rats

Pulmonary fibrosis induced by prolonged exposure to silica particles is a chronic and irreversible lung disease without effective treatment till now. Our previous study has shown that early intervention with MARCO antagonist PolyG could alleviate pulmonary fibrosis in silica-exposed rats. However, the therapeutic effects of PolyG on silica-induced pulmonary fibrosis have rarely been reported. In this study, we explored the effects of administration (on the 28th day after silica exposure) of PolyG (MARCO inhibitor) on an established rat silicosis model. The lungs were analyzed histopathologically in rats using HE and Masson staining. The silica-induced ERS-related apoptosis, EMT and fibrosis were evaluated using western blotting, qRT-PCR and immunohistochemical analyses. The results suggested that silica exposure could increase the MARCO activity, and induce ERS and EMT in lung tissues. Pharmacological targeting of MARCO with PolyG attenuated the development of pulmonary fibrosis in silica-exposed rats. Further study indicated that PolyG could inhibit silica-induced ERS-related apoptosis and EMT process. Together, our findings reveal an essential function of ERS-related apoptosis and EMT in the processes of pulmonary fibrosis caused by silica, and identify MARCO as a potential therapeutic pharmacological target for silicosis.

Inhibition of MARCO ameliorates silica-induced pulmonary fibrosis by regulating epithelial-mesenchymal transition

Epithelial-mesenchymal transition (EMT) is linked to fibrosis following exposure to silica. The scavenger receptor, macrophage receptor with collagenous structure (MARCO) plays an important role in silica-induced inflammation, however, the effect of MARCO on silica-induced fibrosis has not been identified. We hypothesized that MARCO would regulate EMT and be involved in the development of silicosis. Herein, we found that MARCO was highly expressed in lung tissue after exposure to silica and a MARCO inhibitor PolyG could alleviate pulmonary fibrosis in vivo. Our results confirmed that the expression of epithelial marker such as E-cadherin decreased, while the expression of mesenchymal markers, including vimentin and α-SMA increased after silica treatment. Furthermore, PolyG administration efficiently blocked the mRNA and protein expression of EMT markers and decreased the level of fibrosis-related transcription factors and proteins, such as Col1a1, Col3a1, Collagen I and Collagen III in the lungs of silica-exposed rats. The findings demonstrate that the macrophage membrane receptor MARCO controls the fibrotic response through regulating EMT in experimental silicosis and suggest a novel target for preventive intervention.

Deficiency of protein-L-isoaspartate (D-aspartate) O-methyl-transferase expression under endoplasmic reticulum stress promotes epithelial mesenchymal transition in lung adenocarcinoma

A prognostic association between the novel chaperone protein-L-isoaspartate (D-aspartate) O-methyltransferase (PIMT) and lung adenocarcinoma has recently been reported. Here, we evaluated the functional roles of PIMT in the progression of lung adenocarcinoma. PIMT expression was detectable in 6 lung adenocarcinoma cell lines: A549, H441, H460, H1650, Calu 1, and Calu 6 cell lines. In A549 and H441 cells, knockdown by PIMT using silencing RNA of PIMT (si-PIMT) and/or small hairpin-RNA (sh-PIMT) induced a decrease in the expression of E-cadherin with an increase in vimentin expression, indicating that the epithelial to mesenchymal transition (EMT) was induced. Cell mobility, including migration and invasion capability, was increased in sh-PIMT A549 stable and si-PIMT H441 cells compared to in control cells. Endoplasmic reticulum (ER) stress, such as Thapsigargin (Tg) stress and hypoxia, induced EMT in A549 cells but not in other cell types, with an increase in GRP78 expression, whereas overexpression of PIMT reduced the EMT and cell invasion under stress conditions. The expression of hypoxia inducible factor-1 alpha (HIF1α) and Twist increased in sh-PIMT A549 and si-PIMT H441 cells, and Tg stress increased HIF1α expression levels in A549 cells in a dose-dependent manner. Moreover, LW6, an HIF1α inhibitor, reduced EMT, cancer invasion, and the levels of Twist in sh-PIMT A549 cells. Our results indicate that deficiency of supplemental PIMT expression under ER stress facilitates EMT and cell invasion in some cell types of lung adenocarcinoma.

Sohlh2 suppresses epithelial to mesenchymal transition in breast cancer via downregulation of IL-8

Breast cancer is one of the deadliest cancers worldwide due to its strong metastasis to other organs. Metastasis of breast cancer involves a complex set of events, including epithelial-mesenchymal transition (EMT) that increases invasiveness of the tumor cells. We previously identified sohlh2 is a tumor suppressor in the pathogenesis of ovarian cancer. However, the functions of sohlh2 in breast cancer cell migration and invasion remain unknown. Here we report a novel sohlh2/IL-8 signaling pathway in the invasive breast cancer. We observed sohlh2 expression was downregulated in the metastatic breast cancer. Ectopic sohlh2 expression in breast cancer cells reduced EMT and inhibited cell migration and invasion in vitro, and metastasis in vivo. Moreover, the depletion of sohlh2 induced the opposite effects to ectopic sohlh2 expression. RNA-Seq data from a sohlh2 knockdown breast cancer cell line showed that after sohlh2 depletion, the mRNA level of interleukin 8 (IL-8) was significantly increased in these cancer cells, which consequently increased secretion of IL-8 protein. Using chromatin immunoprecipitation and reporter assays, we demonstrated that sohlh2 bound to IL-8 promoter and repressed its activities. The enhanced migration and invasion in sohlh2 -ablated MCF-7 cells were blocked by knockdown of IL-8 expression, while exogenous IL-8 neutralized the anti-migratory and invasive activities of sohlh2 in MDA-MB-231cells. Overall, these results demonstrate that sohlh2 functions as a tumor metastasis suppressor via suppressing IL-8 expression in breast cancer.

The Potential Role of Bile Acids in Acquired Laryngotracheal Stenosis

OBJECTIVE

Gastroesophageal reflux is thought to be a risk factor for laryngotracheal stenosis. Bile acids are a component of gastric refluxate and have previously been implicated in the development of fibrosis in other airway subsites. There is clear evidence that bile acids reflux into the upper airway. We therefore investigated the potential role of bile acids in the pathophysiology of laryngotracheal fibrosis and stenosis, specifically investigating the highly conserved process of epithelial-mesenchymal transition (EMT).

STUDY DESIGN

Translational research study.

METHODS

Human primary tracheal epithelial cells (PTECs) were challenged with the four most common digestive bile acids (cholic, chenodeoxycholic, deoxycholic, and lithocholic). EMT markers transforming growth factor (TGF)-β1, Matrix metalloproteinase (MMP)-9, and procollagen proteins were measured in the supernatant at 48 hours via enzyme-linked immunosorbent assay. Real-time polymerase chain reaction was also used to measure E-cadherin and fibronectin expression.

RESULTS

Significantly greater concentrations of TGF-β1 and MMP-9 were measured in the culture supernatants of cells treated with each bile acid at 10 µmol/L. Lithocholic acid and deoxycholic acid induced significantly increased expression of procollagen protein. Upregulation of fibronectin and downregulation of E-cadherin were observed with all bile acids, except for deoxycholic acid.

CONCLUSION

This is the first proof of principle demonstration that physiologically relevant bile acid challenge induces EMT mechanisms in PTECs. This implies a potential role for bile acids in laryngotracheal scarring and airway remodeling of potential translational significance in laryngotracheal stenosis.

LEVEL OF EVIDENCE

NA. Laryngoscope, 128:2029-2033, 2018.

Near infrared dye loaded copper sulfide-apoferritin for tumor imaging and photothermal therapy

Development of photothermal agents for imaging-guided photothermal therapy (PTT) has been of great interest in the field of nanomedicine. CuS-apoferritin was prepared by a biomimetic synthesis method by using the inside cavity of apoferritin to control the size of CuS nanoparticles. Then, a water-soluble near infrared (NIR) dye (MBA) was bound with CuS-apoferritin, forming a nanocomplex (CuS-apoferritin-MBA) with greatly enhanced photothermal conversion efficiency compared to CuS-apoferritin. The unique optical behavior of CuS-apoferritin-MBA enables fluorescence imaging and photothermal therapy at separated optical wavelengths both, with optimized performances. CuS-apoferritin-MBA was then utilized as a photothermal agent for imaging-guided photothermal therapy in tumor-bearing mouse models. As revealed by in vivo fluorescence imaging, CuS-apoferritin-MBA showed high tumor uptake owing to an enhanced permeability and retention effect and the active targeting of apoferritin. In vivo photothermal therapy experiments indicated that tumors could be ablated by combining CuS-apoferritin-MBA with irradiation of an 808 nm laser. Thus, our work presents a safe, simple photothermal nanocomplex, promising for future clinical translation in cancer treatment.

Development of photothermal agents for imaging-guided photothermal therapy (PTT) has been of great interest in the field of nanomedicine.

CSN5 Promotes Hepatocellular Carcinoma Progression by SCARA5 Inhibition Through Suppressing β-Catenin Ubiquitination

BACKGROUND

Increasing evidence has suggested that E3 Ubiquitin Ligase CSN5 is a newly characterized oncogene involved in various types of cancer. Scavenger receptor class A member 5 (SCARA5) is an important regulator of biological processes in cancer cells. However, the roles and relationship of CSN5 and SCARA5 in hepatocellular carcinoma (HCC) remain unclear.

METHODS

We used RT-PCR, Western blot, and immunohistochemistry to measure CSN5 and SCARA5 expression in HCC tissues and corresponding non-tumor tissues. The CSN5 gene was overexpressed or silenced with lentiviral vectors in HCC cells. Cell proliferation was measured using CCK8 assay. And, the cell migration and invasion were analyzed by transwell assay.

RESULTS

We found that the expressions of CSN5 and SCARA5 are inversely correlated in HCC tissues, and CSN5 expression levels were negatively correlated with the levels of SCARA5 in various HCC cells. Furthermore, we found that high level of CSN5 expression correlated closely with tumor TNM stage, tumor size, and venous metastasis, but low level of SCARA5 expression correlated closely with tumor TNM stage, tumor size, and venous metastasis. Additionally, survival of patients with lower expression of CNS5 was significantly better than that of higher expression group, but the survival of patients with higher expression of SCARA5 was significantly better than that of lower expression group. Moreover, knockdown of CSN5 increased SCARA5 expression and inhibited the proliferation and metastasis of HCC cells in vitro and in vivo. Finally, we found that CSN5 regulated SCARA5 expression by modulating β-catenin. Mechanistically, our results indicate that CSN5 can decrease β-catenin ubiquitination to enhance the protein expression of SCARA5 in HCC cells.

CONCLUSIONS

Our data identified CSN5 as a critical oncoprotein involved in progression of HCC cells, which could serve as a potential therapeutic target in HCC patients.

Human lung epithelial cells A549 epithelial-mesenchymal transition induced by PVA/Collagen nanofiber

Epithelial-mesenchymal transition (EMT) is a process by which epithelial cells lose their cell-cell contact to become mesenchymal stem cells, which is important on development and embryogenesis, wound healing, and cancer metastasis. This research aims to investigate the effect of topological cue as modulating factor on the EMT by tuning the diameter of electrospinning nanofiber. The cell-nanofiber interaction between human lung epithelial cell A549 and electrospinning nanofibers composed of polyvinyl alcohol (PVA) and type I collagen were investigated. The electrospinning of regenerated PVA/Collagen nanofibers were performed with water/acetic acid as a spinning solvent and glutaraldehyde as a chemical cross-linker. Parameterization on concentration, applied voltage and feeding rate was finalized to generate smooth nanofibers with good homogeneity. The scanning electron microscopy result demonstrated that A549 cell appropriately achieved extended morphology by the filopodia attaching to the surface of the nanofibrous mats. When the diameter changed from 90nm to 240nm, the A549 cell was correspondingly express varied EMT related genes. Gene expression analysis was conducted by qPCR using three typical markers for detecting EMT: N-cadherin (NCad), Vimentin (Vim), and Fibronectin (Fib). An increasing expression pattern was observed on cell culturing on 170nm sample with respect to cell cultured on 90nm and 240nm. This result indicated the 170nm PVA/Collagen nanofibers induce A549 cells to process epithelial-mesenchymal transition more seriously than those on 90nm or 240nm.

Methylation analysis of p16, SLIT2, SCARA5, and Runx3 genes in hepatocellular carcinoma

This study is to investigate the methylation status of multiple tumor suppressor 1 (p16), secreted glycoprotein 2 (SLIT2), scavenger receptor class A, member 5 putative (SCARA5), and human runt-related transcription factor 3 (Runx3) genes in the peripheral blood of hepatocellular carcinoma (HCC).This is a case-control study. The peripheral blood samples were collected from 25 HCC patients, 25 patients with high risk of HCC (defined as "internal control group"), and 25 healthy individuals (defined as "external control group"), respectively. Then the methylation status of p16, SLIT2, SCARA5, and Runx3 genes in the blood samples were analyzed by pyrosequencing. The relationship between the methylation and the clinical features of HCC patients were evaluated.The methylation levels in the 7 CpG loci of p16 gene in HCC patients were low and without statistically significant difference (P > .05) compared to the control groups. Although the methylation levels of CpG3 and CpG4 in SLIT2 gene loci were higher than those of the control groups, there was no statistically significant difference (P > .05). However, the methylation rate of CpG2 locus in SCARA5 gene in HCC patients was significantly higher (P < .05). And the methylation rates of CpG1, CpG2, CpG3, CpG4, CpG5, and CpG8 in Runx3 gene in HCC patients were significantly different to that of control groups (P < .05). We also have analyzed the correlations between the CpG islands methylation of Runx3 or SCARA5 genes and the age, gender, hepatitis B, liver cirrhosis, alpha fetal protein, or hepatitis B surface antigen (HBsAg) of the HCC patients, which all showed no significant correlations (P > .05).The methylation status of SCARA5 and Runx3 genes are abnormal in HCC patients, which may further be used as molecular markers for early auxiliary diagnosis of liver cancer.

Effects of Curcumin on Tobacco Smoke-induced Hepatic MAPK Pathway Activation and Epithelial-Mesenchymal Transition In Vivo

Tobacco smoke is a major risk factor for hepatic cancer. Epithelial-mesenchymal transition (EMT) induced by tobacco smoke is crucially involved in the initiation and development of cancer. Mitogen-activated protein kinase (MAPK) pathways play important roles in tobacco smoke-associated carcinogenesis including EMT process. The chemopreventive effect of curcumin supplementation against cancers has been reported. In this study, we investigated the effects of tobacco smoke on MAPK pathway activation and EMT alterations, and then the preventive effect of curcumin was examined in the liver of BALB/c mice. Our results indicated that exposure of mice to tobacco smoke for 12 weeks led to activation of ERK1/2, JNK, p38 and ERK5 pathways as well as activator protein-1 (AP-1) proteins in liver tissue. Exposure of mice to tobacco smoke reduced the hepatic mRNA and protein expression of the epithelial markers, while the hepatic mRNA and protein levels of the mesenchymal markers were increased. Treatment of curcumin effectively attenuated tobacco smoke-induced activation of ERK1/2 and JNK MAPK pathways, AP-1 proteins and EMT alterations in the mice liver. Our data suggested the protective effect of curcumin in tobacco smoke-triggered MAPK pathway activation and EMT in the liver of BALB/c mice, thus providing new insights into the chemoprevention of tobacco smoke-associated hepatic cancer. Copyright © 2017 John Wiley & Sons, Ltd.

STIM1 silencing inhibits the migration and invasion of A549 cells

The present study aimed to explore the effects of stromal interaction molecule 1 (STIM1) knockdown on the migration, invasion and metastasis of A549 cells in vitro and in vivo. Western blotting and immunohistochemistry were used to detect protein expression levels. Wound healing and Transwell invasion assays were used to assess the migratory and invasive abilities of A549 cells transfected with STIM1-specific short hairpin (sh)RNA (shSTIM1). In addition, a tail vein metastatic assay was performed. The results demonstrated that the frequency of STIM1 high-expression was significantly increased in metastatic lung cancer tissues (72.2%) compared with in non-metastatic lung cancer tissues (33.0%). STIM1 knockdown inhibited A549 cell migration and invasion in vitro and tumor metastasis in vivo. The protein expression levels of Snail1, Vimentin, matrix metalloproteinase (MMP) 2 and MMP9 were markedly decreased in A549-shSTIM1 compared with in A549 cells transfected with control shRNA (shcon). In addition, the protein expression levels of E-cadherin were markedly increased in A549-shSTIM1 cells compared with in A549-shcon cells. These results suggested that STIM1 knockdown may inhibit the migration and invasion of A549 cells in vitro, and metastasis in vivo.

A novel SHARPIN-PRMT5-H3R2me1 axis is essential for lung cancer cell invasion

SHARPIN (Shank-associated RH domain interacting protein) is the main component of the linear ubiquitin chain activation complex (LUBAC). SHARPIN is involved in regulating inflammation and cancer progression. However, whether SHARPIN plays an important role in lung cancer metastasis and the potential underlying mechanism are still unknown. Here, for the first time, we reported that SHARPIN expression is closely related to lung cancer progression. Moreover, SHARPIN plays a central role in controlling lung cancer cell metastasis. Mechanistic studies further revealed that PRMT5 (Protein arginine methyltransferase 5), responsible for catalyzing arginine methylation on histones, is a novel cofactor of SHARPIN. This finding provides the basis for further study of the crosstalk between protein ubiquitination and histone methylation. We further found that SHARPIN-PRMT5 is essential for the monomethylation of histones of chromatins at key metastasis-related genes, defining a new mechanism regulating cancer invasion. A novel MLL complex (ASH2 and WDR5) was implied in the link between histone arginine2 monomethylation (H3R2me1) and histone lysine4 trimethylation (H3K4me3) for the activation of metastasis-related genes. These novel findings establish a new epigenetic paradigm in which SHARPIN-PRMT5 has distinct roles in orchestrating chromatin environments for cancer-related genes via integrating signaling between H3R2me1 and H3K4me3.

ERK5 regulates tobacco smoke‑induced urocystic epithelial‑mesenchymal transition in BALB/c mice

Tobacco smoke (TS) is an important risk factor of bladder cancer. Epithelial‑mesenchymal transition (EMT) is involved in the initiation and development of cancer. The role of extracellular signal‑regulated kinase (ERK) 5 in regulating TS‑induced EMT remains to be elucidated. The aim of the present study was to investigate the regulatory role of ERK5 in TS‑triggered EMT in the bladder of mice. BALB/c mice were used for an in vivo TS exposure model. Mice were treated for 6 h a day for 12 weeks. The results demonstrated that mice exposed to TS had decreased mRNA and protein expression levels of the epithelial markers E‑cadherin and zonula occludens‑1, whereas expression levels of the mesenchymal markers Vimentin and N‑cadherin were increased. Treatment with XMD8‑92, a highly specific ERK5 inhibitor, effectively abrogated TS‑triggered activation of ERK5, activator protein‑1 and EMT alterations in the bladder of BALB/c mice. The data suggested that ERK5 regulates TS‑mediated urocystic EMT. These findings provide insight into the molecular mechanisms of TS‑associated bladder tumorigenesis.

Cigarette smoke extract induces epithelial-mesenchymal transition of human bladder cancer T24 cells through activation of ERK1/2 pathway

Bladder cancer is a common genitourinary malignant disease worldwide. Abundant evidence has shown that cigarette smoke (CS) is a crucial risk factor for bladder cancer. Nevertheless, the mechanism underlying the relationship between cigarette smoking and bladder cancer remains unclear. In the present study, we investigated the effects of cigarette smoke extract (CSE) on mitogen-activated protein kinase (MAPK) pathway activation and EMT alterations in human bladder cancer T24 cells, and the preventive effect of extracellular regulated protein kinases 1 and 2 (ERK1/2) inhibitor U0126 was further examined. Our results illustrated that CSE exposure induced morphological change of human bladder cancer T24 cells, enhanced migratory and invasive capacities, reduced epithelial marker expression and elevated mesenchymal marker expression. Meanwhile, exposure of T24 cells to CSE resulted in activation of ERK1/2 pathway as well as activator protein 1 (AP-1) proteins. Interestingly, treatment with ERK1/2 inhibitor U0126 effectively abrogated CSE-triggered EMT and ERK1/2/AP-1 activation. These findings provide novel insight into the molecular mechanisms of CS-associated bladder cancer and may open up new avenues in the search for potential target of bladder cancer intervention.

OLA1 contributes to epithelial-mesenchymal transition in lung cancer by modulating the GSK3β/snail/E-cadherin signaling

Obg-like ATPase 1 (OLA1) belongs to the Obg family of P-loop NTPases, and may serve as a "molecular switch" regulating multiple cellular processes. Aberrant expression of OLA1 has been observed in several human malignancies. However, the role of OLA1 in cancer progression remains poorly understood. In this study, we used the Kaplan-Meier plotter search tool to show that increased expression of OLA1 mRNA was significantly associated with shorter overall survival in lung cancer patients. By immunohistochemical analysis we discovered that levels of OLA1 protein in lung cancer tissues were positively correlated with TNM stage and lymph node metastasis, but negatively correlated with the epithelial-mesenchymal transition (EMT) marker E-cadherin. Knockdown of OLA1 in a lung adenocarcinoma cell line rendered the cells more resistant to TGF-β-induced EMT and the accompanied repression of E-cadherin. Furthermore, our results demonstrated that OLA1 is a GSK3β-interacting protein and inhibits GSK3β activity by mediating its Ser9 phosphorylation. During EMT, OLA1 plays an important role in suppressing the GSK3β-mediated degradation of Snail protein, which in turn promotes downregulation of E-cadherin. These data suggest that OLA1 contributes to EMT by modulating the GSK3β/Snail/E-cadherin signaling, and its overexpression is associated with clinical progression and poor survival in lung cancer patients.

Rock2 promotes RCC proliferation by decreasing SCARA5 expression through β-catenin/TCF4 signaling

Rho-associated coiled-coil forming protein kinase 2 (Rock2), as a key effector of the small GTPase RhoA, is involved in tumor development. Scavenger receptor class A member 5 (SCARA5) is an important regulator of biological processes in cancer cells. However, the roles and relationship of Rock2 and SCARA5 in renal cell carcinoma (RCC) remain unclear. In this study, we found that Rock2 expression was markedly increased in clinical RCC tissues compared with that in adjacent non-cancerous tissues. High expression of Rock2 was inversely correlated with patient survival in RCC, which indicated that Rock2 may be a prognostic marker in human RCC. In addition, Rock2 knockdown increased SCARA5 expression and suppressed RCC cell proliferation both in vitro and in vivo. Furthermore, we found that the β-catenin/TCF4 pathway contributed to the effect of Rock2 on SCARA5-mediated RCC proliferation. Taken together, these results suggest that this newly identified Rock2-β-catenin/TCF4-SCARA5 axis will provide novel insight into the understanding of the regulatory mechanisms of proliferation in human RCC.

MEIS3 is repressed in A549 lung epithelial cells by deoxynivalenol and the repression contributes to the deleterious effect

Deoxynivalenol (DON) is an important Fusarium toxin of concern for food safety. The inhalation of powder contaminated with DON is possible and may cause lung toxicity. In this study, we analyzed the gene expression profile of A549 cells treated for 24 hr with 0.2 µg/mL DON by microarray analysis. In total, 16 genes and 5 noncoding RNAs were significantly affected by DON treatment. The repression of B3GALT4, MEIS3, AK7, SEMA3A, KCNMB4, and SCARA5 was confirmed by quantitative PCR. We investigated the DON toxicity on A549 cells that exogenously expressed these 6 genes. The result indicated that A549 cells that transiently expressed MEIS3 were tolerant to the deleterious effects of DON. Our data show that DON affected the expression of genes with various functions, and suggest that the repression of MEIS3 plays roles in the deleterious effect of DON in A549 lung epithelial cells.

EGCG Suppresses ERK5 Activation to Reverse Tobacco Smoke-Triggered Gastric Epithelial-Mesenchymal Transition in BALB/c Mice

Tobacco smoke is an important risk factor of gastric cancer. Epithelial-mesenchymal transition is a crucial pathophysiological process in cancer development. ERK5 regulation of epithelial-mesenchymal transition may be sensitive to cell types and/or the cellular microenvironment and its role in the epithelial-mesenchymal transition process remain elusive. Epigallocatechin-3-gallate (EGCG) is a promising chemopreventive agent for several types of cancers. In the present study we investigated the regulatory role of ERK5 in tobacco smoke-induced epithelial-mesenchymal transition in the stomach of mice and the preventive effect of EGCG. Exposure of mice to tobacco smoke for 12 weeks reduced expression of epithelial markers E-cadherin, ZO-1, and CK5, while the expression of mesenchymal markers Snail-1, Vimentin, and N-cadherin were increased. Importantly, we demonstrated that ERK5 modulated tobacco smoke-mediated epithelial-mesenchymal transition in mice stomach, as evidenced by the findings that tobacco smoke elevated ERK5 activation, and that tobacco smoke-triggered epithelial-mesenchymal transition was reversed by ERK5 inhibition. Treatment of EGCG (100 mg/kg BW) effectively attenuated tobacco smoke-triggered activation of ERK5 and epithelial-mesenchymal transition alterations in mice stomach. Collectively, these data suggested that ERK5 was required for tobacco smoke-triggered gastric epithelial-mesenchymal transition and that EGCG suppressed ERK5 activation to reverse tobacco smoke-triggered gastric epithelial-mesenchymal transition in BALB/c mice. These findings provide new insights into the mechanism of tobacco smoke-associated gastric tumorigenesis and the chemoprevention of tobacco smoke-associated gastric cancer.

A TGFβ-PRMT5-MEP50 axis regulates cancer cell invasion through histone H3 and H4 arginine methylation coupled transcriptional activation and repression

Protein arginine methyltransferase 5 (PRMT5) complexed with MEP50/WDR77 catalyzes arginine methylation on histones and other proteins. PRMT5-MEP50 activity is elevated in cancer cells and its expression is highly correlated with poor prognosis in many human tumors. We demonstrate that PRMT5-MEP50 is essential for transcriptional regulation promoting cancer cell invasive phenotypes in lung adenocarcinoma, lung squamous cell carcinoma and breast carcinoma cancer cells. RNA-Seq transcriptome analysis demonstrated that PRMT5 and MEP50 are required to maintain expression of metastasis and Epithelial-to-mesenchymal transition (EMT) markers and to potentiate an epigenetic mechanism of the TGFβ response. We show that PRMT5-MEP50 activity both positively and negatively regulates expression of a wide range of genes. Exogenous TGFβ promotes EMT in a unique pathway of PRMT5-MEP50 catalyzed histone mono- and dimethylation of chromatin at key metastasis suppressor and EMT genes, defining a new mechanism regulating cancer invasivity. PRMT5 methylation of histone H3R2me1 induced transcriptional activation by recruitment of WDR5 and concomitant H3K4 methylation at targeted genes. In parallel, PRMT5 methylation of histone H4R3me2s suppressed transcription at distinct genomic loci. Our decoding of histone methylarginine at key genes supports a critical role for complementary PRMT5-MEP50 transcriptional activation and repression in cancer invasion pathways and in response to TGFβ stimulation and therefore and orients future chemotherapeutic opportunities.

Musashi-2 (MSI2) supports TGF-β signaling and inhibits claudins to promote non-small cell lung cancer (NSCLC) metastasis

Non-small cell lung cancer (NSCLC) has a 5-y survival rate of ∼16%, with most deaths associated with uncontrolled metastasis. We screened for stem cell identity-related genes preferentially expressed in a panel of cell lines with high versus low metastatic potential, derived from NSCLC tumors of Kras(LA1/+);P53(R172HΔG/+) (KP) mice. The Musashi-2 (MSI2) protein, a regulator of mRNA translation, was consistently elevated in metastasis-competent cell lines. MSI2 was overexpressed in 123 human NSCLC tumor specimens versus normal lung, whereas higher expression was associated with disease progression in an independent set of matched normal/primary tumor/lymph node specimens. Depletion of MSI2 in multiple independent metastatic murine and human NSCLC cell lines reduced invasion and metastatic potential, independent of an effect on proliferation. MSI2 depletion significantly induced expression of proteins associated with epithelial identity, including tight junction proteins [claudin 3 (CLDN3), claudin 5 (CLDN5), and claudin 7 (CLDN7)] and down-regulated direct translational targets associated with epithelial-mesenchymal transition, including the TGF-β receptor 1 (TGFβR1), the small mothers against decapentaplegic homolog 3 (SMAD3), and the zinc finger proteins SNAI1 (SNAIL) and SNAI2 (SLUG). Overexpression of TGFβRI reversed the loss of invasion associated with MSI2 depletion, whereas overexpression of CLDN7 inhibited MSI2-dependent invasion. Unexpectedly, MSI2 depletion reduced E-cadherin expression, reflecting a mixed epithelial-mesenchymal phenotype. Based on this work, we propose that MSI2 provides essential support for TGFβR1/SMAD3 signaling and contributes to invasive adenocarcinoma of the lung and may serve as a predictive biomarker of NSCLC aggressiveness.

AP-1-mediated chromatin looping regulates ZEB2 transcription: new insights into TNFα-induced epithelial-mesenchymal transition in triple-negative breast cancer

The molecular determinants of malignant cell behaviour in triple-negative breast cancer (TNBC) are poorly understood. Recent studies have shown that regulators of epithelial-mesenchymal transition (EMT) are potential therapeutic targets for TNBC. In this study, we demonstrate that the inflammatory cytokine TNFα induces EMT in TNBC cells via activation of AP-1 signaling and subsequently induces expression of the EMT regulator ZEB2. We also show that TNFα activates both the PI3K/Akt and MAPK/ERK pathways, which act upstream of AP-1. We further investigated in detail AP-1 regulation of ZEB2 expression. We show that two ZEB2 transcripts derived from distinct promoters are both expressed in breast cancer cell lines and breast tumor samples. Using the chromosome conformation capture assay, we demonstrate that AP-1, when activated by TNFα, binds to a site in promoter 1b of the ZEB2 gene where it regulates the expression of both promoter 1b and 1a, the latter via mediating long range chromatin interactions. Overall, this work provides a plausible mechanism for inflammation-induced metastatic potential in TNBC, involving a novel regulatory mechanism governing ZEB2 isoform expression.

Knockdown of SCARA5 inhibits PDGF-BB-induced vascular smooth muscle cell proliferation and migration through suppression of the PDGF signaling pathway

Vascular smooth muscle cell (VSMC) proliferation and migration are critical in the progression of atherosclerosis and can be induced by platelet-derived growth factor (PDGF). Several studies have demonstrated that scavenger receptor class A, member 5 (SCARA5) is important in cancer cell migration and invasion. However, the role of SCARA5 in VSMCs remains to be elucidated in the development of atherosclerosis. Therefore, the role of SCARA5 was investigated in PDGF‑BB‑stimulated VSMC proliferation and migration. In the present study, it was shown that SCARA5 expression was enhanced by PDGF‑BB in human aortic smooth muscle cells (HASMCs). Knockdown of SCARA5 by small interfering (si)RNA significantly inhibited PDGF‑BB‑induced HASMC proliferation and migration. Furthermore, siRNA‑SCARA5 significantly inhibited the phosphorylation of PDGF receptor (PDGFR) β, AKT and extracellular signal‑regulated kinase 1/2 in PDGF‑BB‑stimulated HASMCs. In conclusion, this study demonstrated that knockdown of SCARA5 inhibits PDGF‑BB‑induced HASMC proliferation and migration through suppression of the PDGF signaling pathway. Thus, SCARA5 may be a novel therapeutic target for preventing or treating vascular diseases involving VSMC proliferation and migration.

Synergistic action of master transcription factors controls epithelial-to-mesenchymal transition

Epithelial-to-mesenchymal transition (EMT) is a complex multistep process in which phenotype switches are mediated by a network of transcription factors (TFs). Systematic characterization of all dynamic TFs controlling EMT state transitions, especially for the intermediate partial-EMT state, represents a highly relevant yet largely unexplored task. Here, we performed a computational analysis that integrated time-course EMT transcriptomic data with public cistromic data and identified three synergistic master TFs (ETS2, HNF4A and JUNB) that regulate the transition through the partial-EMT state. Overexpression of these regulators predicted a poor clinical outcome, and their elimination readily abolished TGF-β-induced EMT. Importantly, these factors utilized a clique motif, physically interact and their cumulative binding generally characterized EMT-associated genes. Furthermore, analyses of H3K27ac ChIP-seq data revealed that ETS2, HNF4A and JUNB are associated with super-enhancers and the administration of BRD4 inhibitor readily abolished TGF-β-induced EMT. These findings have implications for systematic discovery of master EMT regulators and super-enhancers as novel targets for controlling metastasis.