Transforming growth factor-β1 treatment of oral cancer induces epithelial-mesenchymal transition and promotes bone invasion via enhanced activity of osteoclasts

The Distinctive Features behind the Aggressiveness of Oral and Cutaneous Squamous Cell Carcinomas

Squamous cell carcinomas arise from stratified squamous epithelia. Here, a comparative analysis based on recent studies defining the genetic alterations and composition of the stroma of oral and cutaneous squamous cell carcinomas (OSCC and CSCC, respectively) was performed. Both carcinomas share some but not all histological and genetic features. This review was focused on how mutations in tumor suppressor genes and protooncogenes cooperate to determine the differentiation, aggressiveness, and metastatic potential of OSCC and CSCC. In fact, driver mutations in tumor suppressor genes are more frequently observed in OSCC than CSCC. These include mutations in TP53 (encoding pP53 protein), CDKN2A (encoding cyclin dependent kinase inhibitor 2A), FAT1 (encoding FAT atypical cadherin 1), and KMT2D (encoding lysine methyltransferase 2D), with the exception of NOTCH (encoding Notch receptor 1), whose mutation frequency is lower in OSCC compared to CSCC. Finally, we describe the differential composition of the tumor microenvironment and how this influences the aggressiveness of each tumor type. Although both OSCC and CSCC tumors are highly infiltrated by immune cells, high levels of tumor-infiltrating lymphocytes (TILs) have been more frequently reported as predictors of better outcomes in OSCC than CSCC. In conclusion, OSCC and CSCC partially share genetic alterations and possess different causal factors triggering their development. The tumor microenvironment plays a key role determining the outcome of the disease.

Loss of MMP-27 Predicts Mandibular Bone Invasion in Oral Squamous Cell Carcinoma

Simple Summary

The growth of oral squamous cell carcinoma into the mandible poses significant challenges to head and neck surgery. The resulting need for extensive procedures has a decisive influence on subsequent esthetics and function and therefore also on the patient’s quality of life. The molecular mechanism behind this remains obscure to date. Hence, we investigated the influence of MMP-27, Osteoprotegerin and RANKL, three proteins with importance in bone remodeling. The results showed that tumors exhibited less bone-invasive behavior in the presence of MMP-27. This may be an incentive for further studies to elucidate the molecular mechanisms of mandibular bone invasion in OSCC.

Abstract

Invasion of the mandibular bone is frequent in oral squamous cell carcinoma (OSCC), which often results in extensive ablative and reconstructive procedures for the patient. The purpose of this single-center, retrospective study was to identify and evaluate potential biomarkers and risk factors for bone invasion in OSCC. Initially, in silico gene expression analysis was performed for different HNSCC tumor T-stages to find factors associated with invasive (T4a) tumor growth. Afterwards, the protein expression of bone-metabolizing MMP-27, TNFRSF11B (Osteoprotegerin, OPG), and TNFSF11 (RANKL) was investigated via Tissue Microarrays (TMAs) for their impact on mandibular bone invasion. TMAs were assembled from the bone–tumor interface of primary OSCCs of the floor of the mouth and gingiva from 119 patients. Sixty-four carcinomas with patho-histological jaw invasion (pT4a) were compared to 55 carcinomas growing along the mandible without invasion (pT2, pT3). Tissue samples were additionally evaluated for patterns of invasion using the WPOI grading system. Statistical analysis of in silico data revealed decreased MMP-27 mRNA expression to be strongly associated with the pT4a-stage in OSCC, indicating invasive tumor growth with infiltration of adjacent anatomical structures. Our own clinico-pathological data on OSCCs presented a significant decrease of MMP-27 in tumors invading the nearby mandible (pT4a), compared to pT2 and pT3 tumors without bone invasion. Loss of MMP27 evolved as the strongest predictor of mandibular bone invasion in binary logistic regression analysis. To our knowledge, this is the first study investigating the role of MMP-27 expression in OSCC and demonstrating the importance of the loss of MMP-27 in mandibular bone invasion.

The roles of osteoprotegerin in cancer, far beyond a bone player

Osteoprotegerin (OPG), also known as tumor necrosis factor receptor superfamily member 11B (TNFRSF11B), is a member of the tumor necrosis factor (TNF) receptor superfamily. Characterized by its ability to bind to receptor activator of nuclear factor kappa B ligand (RANKL), OPG is critically involved in bone remodeling. Emerging evidence implies that OPG is far beyond a bone-specific modulator, and is involved in multiple physiological and pathological processes, such as immunoregulation, vascular function, and fibrosis. Notably, numerous preclinical and clinical studies have been conducted to assess the participation of OPG in tumorigenesis and cancer development. Mechanistic studies have demonstrated that OPG is involved in multiple hallmarks of cancer, including tumor survival, epithelial to mesenchymal transition (EMT), neo-angiogenesis, invasion, and metastasis. In this review, we systematically summarize the basis and advances of OPG from its molecular structure to translational applications. In addition to its role in bone homeostasis, the physiological and pathological impacts of OPG on human health and its function in cancer progression are reviewed, providing a comprehensive understanding of OPG. We aim to draw more attention to OPG in the field of cancer, and to propose it as a promising diagnostic or prognostic biomarker as well as potential therapeutic target for cancer.

Significance of cancer stroma for bone destruction in oral squamous cell carcinoma using different cancer stroma subtypes

Stromal cells in the tumor microenvironment (TME) can regulate the progression of numerous types of cancer; however, the bone invasion of oral squamous cell carcinoma (OSCC) has been poorly investigated. In the present study, the effect of verrucous SCC-associated stromal cells (VSCC-SCs), SCC-associated stromal cells (SCC-SCs) and human dermal fibroblasts on bone resorption and the activation of HSC-3 osteoclasts in vivo were examined by hematoxylin and eosin, AE1/3 (pan-cytokeratin) and tartrate-resistant acid phosphatase staining. In addition, the expression levels of matrix metalloproteinase (MMP)9, membrane-type 1 MMP (MT1-MMP), Snail, receptor activator of NF-κB ligand (RANKL) and parathyroid hormone-related peptide (PTHrP) in the bone invasion regions of HSC-3 cells were examined by immunohistochemistry. The results suggested that both SCC-SCs and VSCC-SCs promoted bone resorption, the activation of osteoclasts, and the expression levels of MMP9, MT1-MMP, Snail, RANKL and PTHrP. However, SCC-SCs had a more prominent effect compared with VSCC-SCs. Finally, microarray data were used to predict potential genes underlying the differential effects of VSCC-SCs and SCC-SCs on bone invasion in OSCC. The results revealed that IL1B, ICAM1, FOS, CXCL12, INS and NGF may underlie these differential effects. In conclusion, both VSCC-SCs and SCC-SCs may promote bone invasion in OSCC by enhancing the expression levels of RANKL in cancer and stromal cells mediated by PTHrP; however, SCC-SCs had a more prominent effect. These findings may represent a potential regulatory mechanism underlying the bone invasion of OSCC.

Aloe vera increases collagen fibres in extracellular matrix and mRNA expression of peroxiredoxin-6 in bovine ovarian cortical tissues cultured in vitro

In vitro culture of ovarian tissue containing primordial follicles is an important tool to study the initiation of follicular populations and to develop efficient culture systems to support in vitro follicle growth. Considering that in vitro culture favours oxidative stress, it is very important to supplement culture medium with antioxidant substances such as Aloe vera extract. This study aims to evaluate the effects of different concentrations of Aloe vera on the distribution of collagen fibres in the extracellular matrix, follicular activation, development and survival in bovine ovarian cortical tissues cultured in vitro, as well as on expression of mRNAs for antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), peroxiredoxin 6 (PRDX6) and glutathione peroxidase 1 (GPX1)]. To this end, ovarian cortical tissues were cultured for 6 days in α-MEM alone or supplemented with different concentrations of Aloe vera extract (1.0, 5.0, 10.0 or 50.0%). After culture, fragments were fixed and processed histologically to evaluate follicular morphology and activation, as well as the extracellular matrix by staining with picrosirius red. The levels of mRNA for SOD, CAT, PRDX6 and GPX1 in cultured ovarian tissues were evaluated by real-time polymerase chain reaction (PCR). Ovarian tissues cultured with 10.0 or 50.0% Aloe vera had higher percentages of collagen fibres than tissues cultured in control medium. A significant increase in developing follicles was observed in ovarian tissues cultured in α-MEM alone or supplemented with 10% Aloe vera when compared with fresh control or tissues cultured with 1.0% Aloe vera. Presence of Aloe vera did not influence the percentage of morphologically normal follicles when compared with control medium. Ovarian tissues cultured with 50.0% Aloe vera had higher percentages of morphologically normal follicles than those cultured with 10.0% Aloe vera. Furthermore, 10% Aloe vera significantly increased mRNA levels for PRDX6. In conclusion, 10.0% Aloe vera improves extracellular matrix distribution in cultured tissues and increases the expression of mRNA for PRDX6 after 6 days in vitro.

FERMT1 knockdown inhibits oral squamous cell carcinoma cell epithelial-mesenchymal transition by inactivating the PI3K/AKT signaling pathway

BACKGROUND

The metastasis of oral cancer is one of the main causes of death. However, the mechanisms underlying oral cancer metastasis have not been completely elucidated. Fermitin family member 1 (FERMT1) plays an -oncogene role in many cancers; however, the role of FERMT1 in oral squamous cell cancer (OSCC) remains unclear.

METHODS

In this study, OSCC cells were treated with 5 ng/ml recombinant human Transforming growth factor-β1 (TGF-β1) protein. FERMT1 expression was measured in OSCC cell lines by RT-qPCR and western blotting. The effect of FERMT1 knockdown on the migration and invasion of OSCC cells was evaluated by Transwell assay. The epithelial-mesenchymal transition (EMT) and PI3K/AKT signaling pathway-related mRNA expression and protein levels were assessed by RT-qPCR and western blotting.

RESULTS

We found that FERMT1 expression was elevated in TGF-β1-induced OSCC cell lines, and knockdown of FERMT1 inhibited the migration and invasion in TGF-β1-induced OSCC cells. FERMT1 silencing inhibited vimentin, N-cadherin, matrix metalloproteinase 9 (MMP-9) expression and promoted E-cadherin expression, suggesting that FERMT1 silencing inhibited EMT in TGF-β1-induced OSCC cells. Furthermore, FERMT1 silencing inactivated the PI3K/AKT signaling pathway in TGF-β1-induced OSCC cells. Activation of the PI3K/AKT signaling pathway reversed the effect of FERMT1 silencing on OSCC cell migration, invasion, and EMT.

CONCLUSIONS

FERMT1 silencing inhibits the migration, invasion, and EMT of OSCC cells via inactivation of the PI3K/AKT signaling pathway, suggesting that FERMT1 is a novel and potential therapeutic target for anti-metastatic strategies for OSCC.

MicroRNA-133 Targets Phosphodiesterase 1C in Drosophila and Human Oral Cancer Cells to Regulate Epithelial-Mesenchymal Transition

Non-coding microRNAs (miRNAs) have been proposed to play diverse roles in cancer biology, including epithelial-mesenchymal transition (EMT) crucial for cancer progression. Previous comparative studies revealed distinct expression profiles of miRNAs relevant to tumorigenesis and progression of oral cancer. With putative targets of these miRNAs mostly validated in vitro, it remains unclear whether similar miRNA-target relationships exist in vivo. In this study, we employed a hybrid approach, utilizing both Drosophila melanogaster and human oral cancer cells, to validate projected miRNA-target relationships relevant to EMT. Notably, overexpression of dme-miR-133 resulted in significant tissue growth in Drosophila larval wing discs. The RT-PCR analysis successfully validated a subset of its putative targets, including Pde1c. Subsequent experiments performed in oral cancer cells confirmed conserved targeting of human PDE1C by hsa-miR-133. Furthermore, the elevated level of miR-133 and its targeting of PDE1C was positively correlated with enhanced migrative ability of oral cancer cells treated with LPS, along with the molecular signature of a facilitated EMT process induced by LPS and TGF-β. The analysis on the RNAseq data also revealed a negative correlation between the expression level of hsa-miR-133 and the survival of oral cancer patients. Taken together, our mammal-to-Drosophila-to-mammal approach successfully validates targeting of PDE1C by miR-133 both in vivo and in vitro, underlying the promoted EMT phenotypes and potentially influencing the prognosis of oral cancer patients. This hybrid approach will further aid to widen our scope in investigation of intractable human malignancies, including oral cancer.

CCL28-induced RARβ expression inhibits oral squamous cell carcinoma bone invasion

Oral squamous cell carcinoma (OSCC) frequently invades the maxillary or mandibular bone, and this bone invasion is closely associated with poor prognosis and survival. Here, we show that CCL28 functions as a negative regulator of OSCC bone invasion. CCL28 inhibited invasion and epithelial-mesenchymal transition (EMT), and its inhibition of EMT was characterized by induced E-cadherin expression and reduced nuclear localization of β-catenin in OSCC cells with detectable RUNX3 expression levels. CCL28 signaling via CCR10 increased retinoic acid receptor-β (RARβ) expression by reducing the interaction between RARα and HDAC1. In addition, CCL28 reduced RANKL production in OSCC and osteoblastic cells and blocked RANKL-induced osteoclastogenesis in osteoclast precursors. Intraperitoneally administered CCL28 inhibited tumor growth and osteolysis in mouse calvaria and tibia inoculated with OSCC cells. RARβ expression was also increased in tumor tissues. In patients with OSCC, low CCL28, CCR10, and RARβ expression levels were highly correlated with bone invasion. Patients with OSCC who had higher expression of CCL28, CCR10, or RARβ had significantly better overall survival. These findings suggest that CCL28, CCR10, and RARβ are useful markers for the prediction and treatment of OSCC bone invasion. Furthermore, CCL28 upregulation in OSCC cells or CCL28 treatment can be a therapeutic strategy for OSCC bone invasion.

LncRNA RHPN1-AS1 Targeting miR-625/REG3A Promotes Cell Proliferation And Invasion Of Glioma Cells

Introduction

Glioma arises from the proliferation of neuroglial cells differentiated from the ectoderm. Evidence has confirmed that differentially expressed long non-coding RNAs (lncRNAs) may be involved in the development and progression of various tumors. The present study aimed to explore the biological function of lncRNA RHPN1-AS1 in glioma.

Materials and methods

The expressions of RHPN1-AS1 in glioma tissues and cells were examined using RT-PCR. Colony formation assay, MTT assay, wound healing assay and transwell assay were performed to detect cell cloning efficiency, proliferation, migration and invasion of glioma cells, respectively. Western blot was applied to assess the expression levels of migration-related and invasion-related proteins. Online bioinformatic tools and luciferase reporter assay were, respectively, employed to predict and verify the downstream target microRNA/gene of RHPN1-AS1.

Results

RHPN1-AS1 was up-regulated in glioma tissues and cells. The cell proliferation, migration and invasion of glioma were inhibited when the expression of RHPN1-AS1 was down-regulated in glioma cells. The expressions of migration-related and invasion-related proteins were also suppressed in siRHPN1-AS1 groups. Furthermore, we predicted and verified that RHPN1-AS1 was directly targeted to miR-625-5p/REG3A. Our study demonstrated that the knockdown of RHPN1-AS1 inhibited the proliferation, migration and invasion activity of glioma cells via regulating miR-625-5p/REG3A expression.

Conclusion

The results revealed that the lncRNA RHPN1-AS1 may be a molecular target in glioma therapy.

Effects of cisatracurium on epithelial-to-mesenchymal transition in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive types of cancer worldwide, with a poor prognosis. The aim of the present study was to investigate the effect of cisatracurium (Cis) on epithelial-to-mesenchymal transition (EMT) in ESCC and its potential mechanism of action. In the present study, Cis was used to treat ECA-109 cells, with cell proliferation measured by a Cell Counting Kit-8 assay and the expression of TGF-β and phospho-Smad2/3 detected by western blotting. TGF-β was then applied to induce EMT. Flow cytometry, wound healing and Transwell assays were used to evaluate cell proliferation, apoptosis, invasion and migration. In addition, cell cycle-related proteins, including cyclin D1, p53 and p21, and EMT-associated proteins, including E-cadherin (E-cad), N-cadherin (N-cad), Vimentin and Slug, were examined by western blot analysis. The results revealed that Cis inhibited the proliferation and promoted apoptosis of ESCC cells. Following treatment with Cis, the expression of TGF-β and phosphorylation of Smad2/3 were downregulated. Cis also suppressed cancer cell invasion and migration induced by TGF-β. In addition, the expression levels of cyclin D1 were decreased, accompanied by increased p53 and p21 expression. In addition, the expression level of E-cad was increased, whereas N-cad, Vimentin and Slug were significantly reduced. Taken together, the results of the present study revealed that exposure of ESCC cells to Cis inhibited EMT and reduced cell invasion and metastasis through the TGF-β/Smad signaling pathway.

The enigmatic role of matrix metalloproteinases in epithelial-to-mesenchymal transition of oral squamous cell carcinoma: Implications and nutraceutical aspects

The most prevalent malignancy in the oral cavity is represented by oral squamous cell carcinoma, an aggressive disease mostly detected in low-income communities. This neoplasia is mostly diffused in older men particularly exposed to risk factors such as tobacco, alcohol, and a diet rich in fatty foods and poor in vegetables. In oral squamous cell carcinoma, a wide range of matrix-cleaving proteinases are involved in extracellular matrix remodeling of cancer microenvironment. In particular, matrix metalloproteinases (MMPs) represent the major and most investigated protagonists. Owing to their strong involvement in malignant pathologies, MMPs are considered the most promising new biomarkers in cancer diagnosis and prognosis. The interest in studying MMPs in oral cancer biology is also owing to their prominent role in epithelial-to-mesenchymal transition (EMT). EMT is an intricate process involving different complex pathways. EMT-related proteins are attractive diagnostic biomarkers that characterize the activation of biological events that promote cancer's aggressive expansion. Different antioncogenic natural compounds have been investigated to counteract oral carcinogenesis, with the scope of obtaining better clinical results and lower morbidity. In particular, we describe the role of different nutraceuticals used for the regulation of MMP-related invasion and proliferation of oral cancer cells.

Unveiling the role of microRNA-7 in linking TGF-β-Smad-mediated epithelial-mesenchymal transition with negative regulation of trophoblast invasion

Several pregnancy complications result from abnormal trophoblast invasion. The dichotomous effect of TGF-β on epithelial-mesenchymal transition (EMT) between trophoblast invasion and cancer progression remains unknown and a critical concern. We attenuated the expression of TGF-β type 1 receptor (coding by TGFBR1) with RNA interference in trophoblastic cells and significantly enhanced the trophoblastic invasion. Analysis of microRNA profiles in trophoblasts indicated microRNA-7 as a key molecule linking TGF-β with the negative regulation of trophoblast invasion. We then attenuated TGFBR1 and miR-7 transcription by transducing either short hairpin RNA targeting TGFBR1 or anti-miR-7-locked nucleonic acid, and we observed an up-regulation of EMT-related transcription factors (TFs) and their downstream effectors, causing a mesenchymal transition of trophoblasts. Conversely, overexpression of TGFBR1 or miR-7 led to the epithelial transition of trophoblasts. Our results showed that TGF-β-induced miR-7 expression negatively modulated the TGF-β-SMAD family member 2-mediated EMT pathway via targeting EMT-related TFs and down-regulating their mesenchymal markers. These findings possibly explain, at least in part, why TGF-β exerts an opposite effect on EMT during trophoblast invasion and cancer progression.-Shih, J.-C., Lin, H.-H., Hsiao, A.-C., Su, Y.-T., Tsai, S., Chien, C.-L., Kung, H.-N. Unveiling the role of microRNA-7 in linking TGF-β-Smad-mediated epithelial-mesenchymal transition with negative regulation of trophoblast invasion.

Inhibition of miR-9-5p suppresses prostate cancer progress by targeting StarD13

Background

This study aims to investigate the effects of inhibiting microRNA-9-5p (miR-9-5p) on the expression of StAR-related lipid transfer domain containing 13 (StarD13) and the progress of prostate cancer.

Methods

The mRNA expression levels of miR-9-5p and StarD13 were determined in several prostate cancer cell lines. We chose DU145 and PC-3 cells for further research. The CCK8 assay was used to measure the cell viability. The cell invasion and wound-healing assays were respectively applied to evaluate invasion and migration. The expression of E-cadherin (E-cad), N-cadherin (N-cad) and vimentin were measured via western blot. DU145 and PC-3 cells overexpressing StarD13 were generated to investigate the variation in proliferation, invasion and migration. A luciferase reporter assay was used to identify the target of miR-9-5p.

Results

Our results show that miR-9-5p was highly expressed and StarD13 was suppressed in prostate cancer cells. MiR-9-5p inhibition repressed the cells’ viability, invasion and migration. It also increased the expression of E-cad and decreased that of N-cad and vimentin. StarD13 overexpression gave the same results as silencing of miR-9-5p: suppression of cell proliferation, invasion and migration. The bioinformatics analysis predicted StarD13 as a target gene of miR-9-5p. Quantitative RT-PCR, western blot analysis and the dual-luciferase reporter assay were employed to confirm the prediction.

Conclusion

Our results show that miR-9-5p plays a powerful role in the growth, invasion, migration and epithelial–mesenchymal transition (EMT) of prostate cancer cells by regulating StarD13. A therapeutic agent inhibiting miR-9-5p could act as a tumor suppressor for prostate cancer.

Association of interleukin-6 (rs1800796) but not transforming growth factor beta 1 (rs1800469) with serum calcium levels in osteoporotic patients

BACKGROUND

Osteoporosis is a multifactorial disease with a strong genetic influence. Recent studies have demonstrated that cytokines, such as TGF-β1 and interleukin 6 (IL-6) play complex roles in the normal bone metabolism and pathophysiology of osteoporosis. Here, we investigated the roles of 2 polymorphisms mapping to the promoters of TGF-β1and IL-6 genes on the genetic susceptibility to osteoporosis as well as calcium and vitamin D levels.

METHODS

A cohort of 297 elderly participants in northern Iran comprising 181 osteoporotic patients (mean age ± SD, 68.36 ± 7.21 years) and 116 unrelated healthy controls (mean age ± SD, 64 ± 5.44 years) was studied for TGF-β1(C-509T) and IL-6 (G-634C) polymorphisms using PCR-RFLP method.

RESULTS

A significant relationship was observed between calcium level and IL-6 genotypes in osteoporotic males (P = 0.011) and females (P = 0.020). No significant differences were observed between osteoporotic and control groups with respect to allele frequency or genotype distribution based on the 2 selected polymorphisms under different genetic models. The results remained the same after comparing the BMD values of either the femur neck or lumbar spine with the genotypes of the elderly men and women when analyzed separately.

CONCLUSION

IL-6 genotype influences serum calcium levels in osteoporotic patients. The lack of association between the common genetic variations of TGF-β1 and IL-6 genes, and BMD highlights the complex genetic background of osteoporosis in the north of Iran.

A correlation study of the expression of HA-CD44st and HER-2 in breast cancer

Background

This study investigated the effect of hyaluronic acid (HA)-CD44st on the invasive ability of human breast cancer MCF-7 cells and the correlation between the expression of CD44st and human epidermal growth factor receptor-2 (HER-2) in postoperative breast cancer patients.

Materials and methods

MCF-7 cells transfected with the eukaryotic expression vector pcDNA3.1-CD44st (MCF/CD44st) were used to examine the effect of the activation of the HA-CD44st-transforming growth factor β (TGFβ)-phosphatidylinositol-3-kinase (PI3K) signaling pathway on the invasive ability of MCF-7 cells. The expression of proteins related to this signaling pathway was assessed by flow cytometry, reverse transcription-polymerase chain reaction, and Western blotting, and the role of AP-1 in the pathway was investigated by electrophoretic mobility shift assay. The effect of pathway activation on the invasion of MCF-7 cells was assessed by Transwell assay, and CD44 expression in breast cancer tissue was detected by immunohistochemistry. Quantitative reverse transcription-polymerase chain reaction was used to detect the expression of CD44st and HER-2 in breast cancer tissue and their correlation was investigated.

Results

HA significantly upregulated HER-2 and TGFβ in MCF-7/CD44st cells, increased p-AKT expression and AP-1 activity, and promoted the invasive ability of tumor cells. CD44st mRNA expression had significant difference between breast cancer tissues and adjacent normal tissues (P < 0.05), and high expression of CD44st mRNA was closely correlated with HER-2 expression in breast cancer tissues.

Conclusion

Binding of HA to the CD44st receptor may regulate the invasiveness of MCF-7 cells through the CD44st/TGFβ/PI3K/AP-1 signaling pathway with increased expression of TGFβ and HER-2. The expression of CD44st mRNA is correlated with HER-2 expression in postoperative breast cancer patients.

Tumor associated macrophages induce epithelial to mesenchymal transition via the EGFR/ERK1/2 pathway in head and neck squamous cell carcinoma

The development of head and neck squamous cell carcinoma (HNSCC) is closely associated with inflammation. Tumor associated macrophages (TAMs), the largest population of inflammatory cells in the tumor stroma, serve an important role in accelerating cancer progression. The present study aimed to investigate the role of TAMs in the metastasis of HNSCC. TAM biomarkers and epithelial to mesenchymal transition (EMT)-associated proteins were detected using immunohistochemical and immunofluorescence staining in HNSCC. Then, direct and indirect co-culture systems of TAMs and HNSCC cells were established. The EMT-associated proteins and associated signaling pathways in HNSCC cells of the co-culture system were measured by reverse transcription-quantitative polymerase chain reaction and western blotting. Finally, hierarchical clustering was performed to analyze associations among TAM biomarkers, epidermal growth factor receptor (EGFR), activated extracellular signal-regulated protein kinase 1/2 (ERK1/2) and EMT-associated proteins in HNSCC tissues. The results indicated that the expression of EMT-associated proteins was positively associated with M2 macrophage biomarkers in HNSCC tissues. Cal27 cells were isolated from the co-culture system by fluorescence-activated cell sorting, and it was identified that E-cadherin was downregulated in Cal27 cells, while Vimentin and Slug were upregulated. Furthermore, the results indicated that EGF released by M2 macrophages in the co-culture served an important role by activating ERK1/2. The correlation and cluster analyses indicated that activated ERK1/2 was positively correlated with cluster of differentiation-163, EGFR, Vimentin and Slug. This suggested that TAMs may induce the EMT of cancer cells by activating the EGFR/ERK1/2 signaling pathway in HNSCC, which may be a promising approach to suppressing cancer metastasis.

Invasion-Related Factors as Potential Diagnostic and Therapeutic Targets in Oral Squamous Cell Carcinoma-A Review

It is well recognized that the presence of cervical lymph node metastasis is the most important prognostic factor in oral squamous cell carcinoma (OSCC). In solid epithelial cancer, the first step during the process of metastasis is the invasion of cancer cells into the underlying stroma, breaching the basement membrane (BM)—the natural barrier between epithelium and the underlying extracellular matrix (ECM). The ability to invade and metastasize is a key hallmark of cancer progression, and the most complicated and least understood. These topics continue to be very active fields of cancer research. A number of processes, factors, and signaling pathways are involved in regulating invasion and metastasis. However, appropriate clinical trials for anti-cancer drugs targeting the invasion of OSCC are incomplete. In this review, we summarize the recent progress on invasion-related factors and emerging molecular determinants which can be used as potential for diagnostic and therapeutic targets in OSCC.

Mutant monocyte chemoattractant protein-1 protein (7ND) inhibits osteoclast differentiation and reduces oral squamous carcinoma cell bone invasion

The seven-amino acid truncated (7ND) protein is an N-terminal deletion mutant of monocyte chemoattractant protein-1 (MCP-1) and it functions as a dominant-negative inhibitor. 7ND and wild-type MCP-1 form a heterodimer, which binds to MCP-1 receptors and inhibits monocyte chemotaxis. In the present study, the 7ND protein was cloned, expressed and purified. An MTT assay revealed that the proliferation of oral squamous cell carcinoma (OSCC) SCC25 cells was not affected following 3 days of treatment with synthetic 7ND protein. Serial dilutions of the 7ND protein were tested for monocyte migration and osteoclast differentiation, and tartrate-resistant acid phosphatase staining demonstrated that significantly fewer osteoclasts were differentiated from cluster of differentiation 14⁺ (CD14⁺) monocytes using magnetic activated cell sorting. Immunofluorescence confirmed these results and significantly less F-actin staining was observed in 7ND-treated osteoclasts. Furthermore, bone invasion was examined by subcutaneously injecting SCC25 cells into the area overlaying the calvariae of nude mice. The results demonstrated that the average tumor volume of SCC25 cells with 7ND protein was similar to the average volume of tumors formed by untreated SCC25 cells. Flow cytometric analysis suggested that the CD14⁺ subpopulation in the bone marrow of 7ND-treated mice was reduced compared with that of untreated mice. Micro-computed tomography imaging revealed significantly less bone resorption in the calvariae injected with SCC25 cells plus the 7ND protein. Taken together, the results of the present study demonstrated the potential therapeutic value of the 7ND protein. The 7ND MCP-1 variant not only functions in vitro to inhibit osteoclast differentiation, but also reduces the progression of bone invasion by OSCC cells in vivo.

Loss of RUNX3 expression inhibits bone invasion of oral squamous cell carcinoma

High recurrence and lower survival rates in patients with oral squamous cell carcinoma (OSCC) are associated with its bone invasion. We identified the oncogenic role of RUNX3 during bone invasion by OSCC. Tumor growth and the generation of osteolytic lesions were significantly inhibited in mice that were subcutaneously inoculated with RUNX3-knockdown human OSCC cells. RUNX3 knockdown enhanced TGF-β-induced growth arrest and inhibited OSCC cell migration and invasion in the absence or presence of transforming growth factor-β (TGF-β), a major growth factor abundant in the bone microenvironment. RUNX3 knockdown induced cell cycle arrest at the G1 and G2 phases and promoted G2 arrest by TGF-β in Ca9.22 OSCC cells. RUNX3 knockdown also inhibited both the basal and TGF-β-induced epithelial-to-mesenchymal transition by increasing E-cadherin expression and suppressing the nuclear translocation of β-catenin. In addition, the expression and TGF-β-mediated induction of parathyroid hormone-related protein (PTHrP), one of key osteolytic factors, was blocked in RUNX3-knockdown OSCC cells. Furthermore, treating human osteoblastic cells with conditioned medium derived from RUNX3-knockdown OSCC cells reduced the receptor activator of nuclear factor-kappaB ligand (RANKL)/osteoprotegerin ratio compared with treatment with conditioned medium from RUNX3-expressing cells. These findings indicate that RUNX3 expression in OSCC cells contributes to their bone invasion and the resulting osteolysis by inducing their malignant behaviors and production of osteolytic factors. RUNX3 alone or in combination with TGF-β and PTHrP may be a useful predictive biomarker and therapeutic target for bone invasion by oral cancer.

Characterization of different osteoclast phenotypes in the progression of bone invasion by oral squamous cell carcinoma

The present study aimed to characterize different phenotypes of osteoclasts in the progression of bone invasion by oral squamous cell carcinoma (OSCC). A local bone invasion model of OSCC was established by injecting SCC25 human OSCC cells into the center of calvariae in nude mice, and all mice were found to have a typical bone resorption area. Staining for tartrate-resistant acid phosphatase (TRAP) revealed various types of giant osteoclasts in the tumour-bone interface. Bone marrow cells (BMCs) were isolated from the nude mice for primary osteoclast culture, but only a few giant osteoclasts were generated. Additionally, special blood centrifuge tubes were utilized to obtain large numbers of peripheral blood mononuclear cells (PBMCs). Using magnetic activated cell sorting (MACS) and the cytokines colony-stimulating factor (CSF) and receptor activator of nuclear factor-κb ligand (RANKL), we differentiated human osteoclasts from CD14+ monocytes of PBMCs. Bone resorption was further confirmed by a bone resorption assay. Finally, Transwell inserts were used for indirect cell co-culture of SCC25 cells and CD14+ monocytes. Expression of specific osteoclast markers was detected by real-time PCR and western blotting. After co-culture for 3 and 6 days, conditioned medium (CM) of SCC25 cells stimulated the expression of osteoclast markers, and additional osteoclasts were detected through staining of TRAP and F-actin. In the present study distinct osteoclast phenotypes were observed in the established bone invasion animal model, and were confirmed using various primary osteoclast cultures. CM of OSCC cells may promote the expression of osteoclast markers and induce the differentiation of monocytes to mature osteoclasts, which can resorb adjacent bone tissue.

miR-222 knockdown suppresses epithelial-to-mesenchymal transitionin human oral squamous cell carcinoma

Tumor metastasis is the main cause of death in patients with oral squamous cell carcinoma (OSCC). Epithelial-to-mesenchymal transition (EMT) is potentially associated with metastasis and histological grading in OSCC. Therefore, the discovery of new strategies to inhibit EMT is potentially valuable for the development of therapies for OSCC. In our previous study, we found that miR-222, which is up-regulated in OSCC, regulates the biological behavior of OSCC cells by targeting the p53-upregulated modulator of apoptosis (PUMA); however, the effect of miR-222 on TGF-β1-induced EMT in OSCC cells is unclear. In this study, OSCC cell lines CAL-27 and Tca-8113 were incubated with 5 ng/ml of TGF-β1 to inhibit the expression of E-cadherin, promote the expression of N-cadherin, vimentin, and α-SMA and stimulate achange in cell shape convert from a "cuboidal" epithelial structure into an elongated mesenchymal shape. We found that the expression of miR-222 was up-regulated during TGF-β1-induced EMT in OSCC cells. In addition, miR-222 knockdown reversed TGF-β1-induced EMT by targeting PUMA. Our findings indicate that miR-222 plays an important role in OSCC, potentially serving as a novel therapeutic target for the treatment of OSCC.

Rab5a is overexpressed in oral cancer and promotes invasion through ERK/MMP signaling

Ras-related protein Rab-5A (Rab5a) has been identified to be overexpressed in several types of human cancer. However, its clinical significance and biological roles in oral cancer remain unclear. In the present study, the protein expression of Rab5a was examined in 79 cases of oral squamous cell carcinoma samples using immunohistochemistry. It was demonstrated that Rab5a protein was upregulated in 49.3% (39/79) of cancer samples. Small interfering RNA knockdown was performed on Detroit 562 cells with high endogenous expression. Rab5a transfection was performed in FaDu cells with low endogenous levels. Rab5a depletion was revealed to inhibit cell growth, invasion and colony formation while its overexpression facilitated cell growth, invasion, and colony formation. In addition, Rab5a facilitated cell cycle progression and cell migration. It was also demonstrated that Rab5a depletion downregulated and its overexpression upregulated the expression levels of various cell cycle-associated proteins, and matrix metalloproteinase-2 (MMP-2). Furthermore, Rab5a positively regulated the extracellular signal-regulated kinase (ERK) signaling pathway and promoted epithelial-mesenchymal transition (EMT). ERK inhibitor PD98059 partially inhibited the role of Rab5a on MMP-2, cyclin D1, cell proliferation and invasion. The results of the present study suggest that Rab5a is overexpressed in oral cancer tissue samples and promotes the malignant phenotype through EMT and the ERK/MMP-2 signaling pathway.

Utilization of E-cadherin by monocytes from tumour cells plays key roles in the progression of bone invasion by oral squamous cell carcinoma

E-cadherin (E-cad) is recently reported to be expressed in early stages of osteoclastogenesis, and blocking E-cad with neutralizing antibodies decreases osteoclast differentiation. Since our previous research demonstrates the loss of E-cad protein in the bone invasion by oral squamous cell carcinoma (OSCC), we hypothesize that E-cad may be utilized by monocytes to fuse and differentiate into osteoclasts. Two research models are used in the present study to explore our hypothesis. On one hand, we use OSCC cells of SCC25 to establish an animal model of bone invasion by OSCC, and investigate whether E-cad protein disappears in vivo; on the other hand, we use the indirect co-culture model of SCC25 and RAW 264.7 cells, with the treatment of transforming growth factor-β1 (TGF-β1), and observe whether the decreased E-cad protein is ‘hijacked’ in vitro. Results showed the animal model of OSCC with bone invasion was successfully established. Immunohistochemistry (IHC) found similar changes of E-cad protein, which was weakly stained by tumour cells. By using 5 ng/ml of TGF-β1, we confirmed the artificial epithelial-mesenchymal transition (EMT) of SCC25 cells, with changes of EMT marker expression and cell morphology. Real-time PCR showed E-cad mRNA decreased in SCC25 while increased in RAW 264.7 of the indirect cell co-culture model, and immunofluoresence (IF) observed the evident switch of E-cad staining from SCC25 to RAW 264.7. With the supplement of receptor activator of NF-κB ligand (RANKL), tartrate-resistant acid phosphatase (TRAP) and F-actin staining confirmed the increased number of osteoclasts. Taken together, our study found the switch of E-cad protein in the progression of bone invasion by OSCC. The loss of E-cad in tumour cells may be utilized by monocytes to differentiate into osteoclasts, thus further explaining the underlying mechanisms of bone invasion by OSCC, which may supply clues for future molecular biotherapies.

Role of matrix metalloproteinase-9 in transforming growth factor-β1-induced epithelial-mesenchymal transition in esophageal squamous cell carcinoma

Epithelial–mesenchymal transition (EMT) is thought to be a crucial event during the early metastasis of tumor cells. Transforming growth factor (TGF)-β1 is involved in the process of EMT in a variety of human malignancies. Matrix metalloproteinase (MMP)-9 plays an important role in tumor invasion and metastasis, and its expression is regulated by various growth factors, including TGF-β1, in different cell types. To date, the role of MMP-9 in TGF-β1-induced EMT in esophageal squamous cell carcinoma (ESCC) remains unclear. In this study, we aimed to elucidate the mechanism underlying MMP-9-mediated TGF-β1 induction of EMT in ESCC. We analyzed the expression of MMP-9, E-cadherin, and vimentin, in ESCC cells (EC-1), before and after the treatment with exogenous TGF-β1 or a broad spectrum MMP inhibitor, GM6001. Additionally, we analyzed the activity of MMP-9 in these cells and performed MMP-9 knockdown experiments. The results obtained in this study demonstrated that the treatment of EC-1 cells with TGF-β1 can induce EMT, together with the upregulation of vimentin and downregulation of E-cadherin expression in a time-dependent manner. The treatment with GM6001 was shown to attenuate TGF-β1-induced EMT. Furthermore, the exposure of EC-1 cells to TGF-β1 increased the expression and activity of MMP-9, while MMP-9 knockdown blocked TGF-β1-induced EMT and inhibited cell invasiveness and migration. Additionally, treatment with the recombinant human MMP-9 was shown to induce EMT and enhance ESCC cell invasion and metastasis. The obtained data suggest that the regulation of MMP-9 by TGF-β1 may represent a novel mechanism underlying TGF-β1-induced EMT in ESCC.

A Comparative Study of Cathepsin D Expression in Peripheral and Central Giant Cell Granuloma of the Jaws by Immunohistochemistry Technique

STATEMENT OF THE PROBLEM

Peripheral and central giant cell granuloma are two common benign lesions of the oral cavity. In spite of histopathological similarities, they have different clinical behaviors. Cathepsin D is a lysosomal enzyme which has different functions on the basis of protein and applied peptide cleavage.

PURPOSE

This research aimed to evaluate and compare the expression level of Cathepsin D in these two lesions to find the reasons for the differences in clinical and biologic characteristics.

MATERIALS AND METHOD

The expression of Cathepsin D was investigated by using the immunohistochemistry method in 20 samples of peripheral giant cell granuloma and 20 samples of central giant cell granuloma. The percentage of stained giant cells (labeling index), the intensity of staining of giant cells, and staining-intensity-distribution in both groups were calculated and compared.

RESULTS

The labeling indices of Cathepsin D in peripheral giant cell granuloma and central giant cell granuloma were 95.9±4.03 and 95.6±2.34, respectively. There was no significant difference in the percentages of stained giant cells between the two groups (p= 0.586). The intensity of staining of giant cells in central giant cell granuloma was stronger than that of peripheral giant cell granuloma (p> 0.001). Staining- intensity- distribution of giant cells in central giant cell granuloma was significantly greater than that of the peripheral type of lesion (p= 0.001).

CONCLUSION

The higher expression level of Cathepsin D in central giant cell granuloma compared to peripheral type of lesion can explain more aggressive behavior of central giant cell granuloma.

Transient transfection of macrophage migration inhibitory factor small interfering RNA disrupts the biological behavior of oral squamous carcinoma cells

Macrophage migration inhibitory factor (MIF) is closely associated with tumorigenesis. The present study aimed to investigate the effects of MIF on the proliferation, migration and colony formation of oral squamous cell carcinoma (OSCC), and to quantify the protein expression levels of MIF in OSCC tissue samples. Firstly, small interfering (si) RNA was used to knock down the gene expression of MIF in Tca8113, HN5 and SCC25 OSCC cells. Secondly, proliferation, migration and colony formation of the OSCC cells were determined by MTT, transmigration and colony formation assays, respectively. Western blotting was performed to detect changes in the protein expression levels of the epithelial mesenchymal transition markers, Twist-related protein 1 (Twist1), matrix metalloproteinase (MMP)-2 and MMP-9. Finally, immunohistochemistry was used to examine the protein expression of MIF in OSCC tissue samples. The results demonstrated that siRNA against MIF significantly downregulated the expression levels of MIF in all OSCC cells, and decreased their proliferation and migration ability. Colony formation ability was also inhibited in the OSCC cells following transfection with MIF siRNA. Furthermore, western blotting demonstrated that the protein expression of Twist1 was decreased similarly to those of MIF. The protein expression of MMP-2 revealed no change, whereas that of MMP-9 decreased. The protein expression of MIF was detected in OSCC tissue samples with staining predominantly located in the cell membrane and cytoplasm. The present study demonstrated that MIF may be important in the pathogenesis and progression of OSCC, and indicated its potential therapeutic value.

Exogenous expression of IL-1Ra and TGF-β1 promotes in vivo repair in experimental rabbit osteoarthritis

OBJECTIVES

Potential gene therapy application of single and co-expression of interleukin 1 (IL-1) receptor antagonist (IL-1Ra) and transforming growth factor-β1 (TGF-β1) to alter disease progression was investigated in an in-vivo rabbit model of osteoarthritis (OA).

METHOD

Sixteen young adult rabbits were randomly and equally divided into four groups: blank control group, IL-1Ra transfection group, TGF-β1 transfection group, and IL-1Ra/TGF-β1 double transfection group. Histological examinations were performed to monitor disease progression after haematoxylin and eosin (H&E) staining of articular cartilage. Immunohistochemistry was used to detect IL-1Ra and TGF-β1 in synovial membrane tissues. Exogenous IL-1Ra and TGF-β1 content was assessed in joint lavage fluid using an enzyme-linked immunosorbent assay (ELISA).

RESULTS

ELISA measurements from the joint lavage fluid showed high expressions of IL-1Ra and TGF-β1 in the single and double transfection groups. Remarkably, concomitant reductions in IL-1β and tumour necrosis factor alpha (TNF-α) levels were observed in these single and double transfection groups. Radioimmunoassay (RIA)-based detection showed that IL-1β and TNF-α levels in the gene transfection groups were significantly lower compared to the blank control group, in parallel experiments. Importantly, injection of IL-1Ra and TGF-β1 expressing cartilage cells into joints led to a significant inhibition of cartilage matrix degradation. Finally, IL-1Ra and TGF-β1 expression in tissues correlated with disease reversal in the experimental group, with improved tissue architecture and collagen deposition.

CONCLUSIONS

Our results reveal that both single- and double-gene transfection of IL-1Ra and TGF-β1 promote extensive repair of damaged cartilage, and double transfections showed better recovery than single transfections, suggesting that co-expression of IL-1Ra and TGF-β1 inhibits degeneration and improves repair of articular cartilage in OA.

Mechanisms of Invasion in Head and Neck Cancer

CONTEXT

The highly invasive properties demonstrated by head and neck squamous cell carcinoma (HNSCC) are often associated with locoregional recurrence and lymph node metastasis in patients and is a key factor leading to an expected 5-year survival rate of approximately 50% for patients with advanced disease. It is important to understand the features and mediators of HNSCC invasion so that new treatment approaches can be developed.

OBJECTIVES

To provide an overview of the characteristics, mediators, and mechanisms of HNSCC invasion.

DATA SOURCES

A literature review of peer-reviewed articles in PubMed on HNSCC invasion.

CONCLUSIONS

Histologic features of HNSCC tumors can help predict prognosis and influence clinical treatment decisions. Cell surface receptors, signaling pathways, proteases, invadopodia function, epithelial-mesenchymal transition, microRNAs, and tumor microenvironment are all involved in the regulation of the invasive behavior of HNSCC cells. Identifying effective HNSCC invasion inhibitors has the potential to improve outcomes for patients by reducing the rate of spread and increasing responsiveness to chemoradiation.

Transforming growth factor-β1 induces EMT by the transactivation of epidermal growth factor signaling through HA/CD44 in lung and breast cancer cells

Epithelial-mesenchymal transition (EMT), a process closely related to tumor development, is regulated by a variety of signaling pathways and growth factors, such as transforming growth factor-β1 (TGF-β1) and epidermal growth factor (EGF). Hyaluronan (HA) has been shown to induce EMT through either TGF-β1 or EGF signaling and to be a regulator of the crosstalk between these two pathways in fibroblasts. In this study, in order to clarify whether HA has the same effect in tumor cells, we utilized the lung cancer cell line, A549, and the breast cancer cell line, MCF-7, and found that the effects of stimulation with TGF-β1 were more potent than those of EGF in regulating the expression of EMT-associated proteins and in enhancing cell migration and invasion. In addition, we observed that TGF-β1 activated EGF receptor (EGFR) and its downstream AKT and extracellular signal-regulated kinase (ERK) pathways. Furthermore, we found that TGF-β1 upregulated the expression of hyaluronan synthases (HAS1, HAS2 and HAS3) and promoted the expression of CD44, a cell surface receptor for HA, which interacts with EGFR, resulting in the activation of the downstream AKT and ERK pathways. Conversely, treatment with 4-methylumbelliferone (4-MU; an inhibitor of HAS) prior to stimulation with TGF-β1, inhibited the expression of CD44 and EGFR, abolished the interaction between CD44 and EGFR. Furthermore, the use of shRNA targeting CD44 impaired the expression of EGFR, deactivated the AKT and ERK pathways, reversed EMT and decreased the migration and invasion ability of cells. In conclusion, our data demonstrate that TGF-β1 induces EMT by the transactivation of EGF signaling through HA/CD44 in lung and breast cancer cells.

αvβ6 integrin is required for TGFβ1-mediated matrix metalloproteinase2 expression

Transforming growth factor (TGF) β1 activity depends on a complex signalling cascade that controls expression of several genes. Among others, TGFβ1 regulates expression of matrix metalloproteinases (MMPs) through activation of Smads. In the present study, we demonstrate for the first time that the αvβ6 integrin interacts with TGFβ receptor II (TβRII) through the β6 cytoplasmic domain and promotes Smad3 activation in prostate cancer (PrCa) cells. Another related αv integrin, αvβ5, as well as the αvβ6/3 integrin, which contains a chimeric form of β6 with a β3 cytoplasmic domain, do not associate with TβRII and fail to show similar responses. We provide evidence that αvβ6 is required for up-regulation of MMP2 by TGFβ1 through a Smad3-mediated transcriptional programme in PrCa cells. The functional relevance of these results is underscored by the finding that αvβ6 modulates cell migration in an MMP2-dependent manner on an αvβ6-specific ligand, latency-associated peptide (LAP)-TGFβ. Overall, these mechanistic studies establish that expression of a single integrin, αvβ6, is sufficient to promote activation of Smad3, regulation of MMP2 levels and consequent catalytic activity, as well as cell migration. Our study describes a new TGFβ1-αvβ6-MMP2 signalling pathway that, given TGFβ1 pro-metastatic activity, may have profound implications for PrCa therapy.

Epithelial-mesenchymal transition in keratocystic odontogenic tumor: possible role in locally aggressive behavior

The aim of this study is to clarify whether epithelial-mesenchymal transition (EMT) is involved in the pathogenesis and development of keratocystic odontogenic tumor (KCOT). The expression levels of EMT-related proteins and genes in normal oral mucosa (OM), radicular cyst (RC), and KCOT were determined and compared by real-time quantitative PCR and immunohistochemistry. Our data showed that the expression of epithelial markers E-cadherin and Pan-cytokeratin was significantly downregulated in KCOT with upregulation of mesenchymal markers N-cadherin compared to OM and RC. Importantly, TGF-β, a potent EMT inducer, and Slug, a master transcription factor, were also found highly expressed in KCOT. In addition, the results from Spearman rank correlation test and clustering analysis revealed the close relationship between Slug and MMP-9, which was further evidenced by double-labeling immunofluorescence that revealed a synchronous distribution for Slug with MMP-9 in KCOT samples. All the data suggested EMT might be involved in the locally aggressive behavior of KCOT.

A single nucleotide polymorphism in the TGF-β1 gene (rs1982073 C>T) may contribute to increased risks of bone fracture, osteoporosis, and osteoarthritis: a meta-analysis

Genetic factors have been shown to be of great importance for the pathogenesis of bone diseases, such as fracture, osteoporosis (OP), and osteoarthritis (OA). However, published studies on the correlations of transforming growth factor-β1 (TGF-β1) gene polymorphisms with bone diseases have been hampered by small sample sizes or inconclusive findings. We hence aimed at examining the relationships between a single nucleotide polymorphism in the TGF-β1 gene (rs1982073 C>T) with bone fracture, OP, and OA risks in this meta-analysis. A systematic electronic search of literature was conducted to identify all published studies in English or Chinese on the association between the TGF-β1 gene and fracture, OP, or OA risks. Data were abstracted independently by two reviewers. To investigate the strength of this relationship, crude odds ratios with 95 % confidence intervals were used. An updated meta-analysis based on nine independent case-control studies were chosen (patients with fracture, OP, or OA = 1569; healthy controls = 1638). Results identified a higher frequency of rs1982073 C>T in patients with fracture, OP, or OA than in healthy controls. Ethnicity and genotyping method-stratified analysis under both models implied that the rs1982073 C>T polymorphism was positively correlated with the risk of fracture, OP, and OA among Asians under detection via the non-PCR-RFLP method. Disease-stratified results yielded that rs1982073 C>T may increase the risk of fracture, OP, and OA under the allele model, but was only significantly related to OP under the dominant model. According to the sample size-stratified analysis, subjects with the rs1982073 C>T polymorphism in the allele model were more likely to develop the three bone diseases in both the small and large sample size groups, and only in the large sample size under the dominant model. Our findings show that TGF-β1 rs1982073 C>T has a modest effect in increasing susceptibility to bone fracture, OP, and OA.

Astragaloside IV inhibits migration and invasion in human lung cancer A549 cells via regulating PKC-α-ERK1/2-NF-κB pathway

The migration and invasion characteristics that are related to inflammatory response play important roles in the development of lung cancer. Astagaloside IV (AS-IV), an effective saponin component isolated from Astragali Radix, has been reported to inhibit metastasis of tumor cells. However, little is known about the underlying mechanism of AS-IV on inhibiting the migration and invasion characteristics of lung cancer cells. In the present study, cell proliferation was assessed by MTT colorimetric assay. Wound-healing assay and transwell chambers assay were used to detect the effects of AS-IV on the migration capacity and invasiveness of A549 cells. Metastasis-related bio-markers expressions were detected by Western blot analysis. Levels of inflammatory factors including transforming growth factor-β1 (TGF-β1), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in cell supernatant were tested by enzyme linked immunosorbent assay (ELISA). The expressions of PKC-α, ERK1/2 and NF-κB were analyzed by Western blot analysis. The results showed that the migration and invasion ability of A549 has been suppressed in presence of AS-IV. The levels of MMP-2, MMP-9 and integrin β1 were decreased significantly, whereas E-cadherin was increased by the treatment of different concentrations AS-IV. Furthermore, AS-IV also significantly decreased TGF-β1, TNF-α and IL-6 levels. Interestingly, PKC pathway inhibitor AEB071 (Sotrastaurin) (0.1 μM) or ERK inhibitor U0126 (1 μM) or NF-κB inhibitor PDTC (1 μM) could affect suppression of AS-IV on cell invasion, at least partially. Our results suggested that the migration and invasion of AS-IV in A549 cells might be related to the PKC-α-ERK1/2-NF-κB pathway. The result indicated that AS-IV could be used as a candidate for the inhibition of metastasis of human lung cancer.

Transforming growth factor-β1-induced epithelial-mesenchymal transition in human esophageal squamous cell carcinoma via the PTEN/PI3K signaling pathway

Epithelial-mesenchymal transition (EMT) is a crucial step for the invasive and metastatic properties of malignant tumor cells during tumor progression. Numerous signaling pathways are involved in the process of EMT in cancer, such as the EMT-inducing signal transforming growth factor (TGF)-β and the recently demonstrated PTEN/PI3K signaling pathway. To date, no data have been reported concerning the influence of PTEN/PI3K signaling pathway on EMT in human esophageal squamous cell carcinoma (ESCC) and how TGF-β1 and PTEN/PI3K act through multiple interconnected signaling pathways to trigger events associated with EMT and tumor progression. Our data showed that the PTEN/PI3K pathway was active in human ESCC tissues in vivo, particularly in ESCC with decreased E-cadherin and increased vimentin protein expression, poor differentiation, deep invasion and lymph node metastasis, which are responsible for EMT and tumor progression. In addition, in the human ESCC cell line (EC-1) in vitro, TGF-β1 treatment markedly induced EMT, including morphological alterations, a decrease of E-cadherin and an increase of vimentin levels and enhanced mobility and invasiveness. Furthermore, the PTEN/PI3K pathway was also activated in the process of TGF-β1-induced EMT in EC-1 cells in vitro, whereas inhibition of the PTEN/PI3K pathway by using pcDNA3.1 PTEN partially blocked TGF-β1-induced EMT and reduced mobility and invasiveness. These studies suggest that TGF-β1 and the PTEN/PI3K signaling pathway contribute to EMT and the PTEN/PI3K signaling pathway is a key regulator of TGF-β1‑induced EMT in ESCC. Disruption of the PTEN/PI3K pathway involved in TGF-β1-induced EMT may provide possible routes for therapeutic intervention to ESCC.