The effect and mechanism of miR-607/CANT1 axis in lung squamous carcinoma

Lung squamous carcinoma (LUSC) is the second most frequent subtype of non-small cell lung cancer. Rarely gene alterations are identified in LUSC. Therefore, identifying LUSC-related genes to explain the relevant molecular mechanism is urgently needed. A potential biomarker, calcium-activated nucleotidase 1 (CANT1), was elevated in tissues of LUSC patients relative to normal cases based on the TCGA and/or GTEx database. CCK-8 and transwell tests were then implemented to measure the proliferative, invasive and migratory capacities, and showed that knockdown of CANT1 blocked LUSC cells proliferation. miR-607, predicted as an upstream factor for CANT1, was declined in LUSC using TargetScan analysis and luciferase activity test. Low miR-607 expression was related with unfavorable outcomes of LUSC patients. Moreover, miR-607 downregulation elevated cell viability, invasion and migration in LUSC cells, which was antagonized by si-CANT1. GEPIA website was accessed to estimate the relevance between CANT1 and epithelial-mesenchymal transition (EMT)-related positive factors. The protein levels of Fibronectin, Vimentin, Snail and β-catenin were altered due to the abnormal CANT1 and miR-607 expression. Together, these data unveiled that miR-607/CANT1 pair may exert a vital role in the progression of LUSC through mediating EMT process, which would furnish an available therapeutic therapy for LUSC.

Effects of Boron on Cytotoxicity, Apoptosis, and Cell Cycle of Cultured Rat Sertoli Cells In vitro

The present study aimed to investigate the effects of the administration of boron on viability, apoptosis, and cell cycle of primary rat Sertoli cells (SCs) in vitro. SCs were aseptically isolated from 18-22-day-old male Sprague-Dawley (SD) rats. SCs were identified with immunofluorescence using anti-vimentin antibody. Further, to investigate the effects of boron on Sertoli cells, SCs of the boron treatment group were exposed to different concentrations (0.25, 0.5, 1, 5, 10, 40, and 80 mmol/L) of boric acid. Using MTT and Cell Counting Kit-8 assays, the impact of boron on SCs viability was analyzed. Cell apoptosis and cycle of SCs were analyzed using flow cytometry. A concentration of 0.5 mmol/L boric acid resulted in the highest viability and lowest necrosis and apoptosis. Above this concentration (even 1.0 mmol/L) showed lower viability and higher levels of necrosis and apoptosis. Administration of < 0.5 mmol/L boron significantly promoted the viability of Sertoli cells (P < 0.01); however, the exposure to high dose (> 10 mmol/L) of boron exhibited significant adverse effects on Sertoli cells (P < 0.01) and even toxic effects, inhibiting cell viability compared to the control group. Flow cytometry analysis showed that treatment with 0.5 mmol/L of boron significantly inhibited the apoptosis of Sertoli cells and the proportion of cells in S and G₂/M phases was markedly increased; however, a higher concentration of 40 and 80 mmol/L of boron promoted Sertoli cell apoptosis and cells were completely arrested at G₀/G₁ phase. Boron at doses below 0.5 mmol/L could significantly improve the viable capacity of testicular Sertoli cells in vitro and inhibit their apoptosis. However, high dose of boron (at a concentration higher than 5.0 mmol/L) exhibited noticeable toxic effects, inhibiting cell viability, accelerating apoptosis of Sertoli cells, and arresting cell cycle at G0/G1 phase.

Loss of ARF/INK4A Promotes Liver Progenitor Cell Transformation Toward Tumorigenicity Supporting Their Role in Hepatocarcinogenesis

Liver progenitor cells (LPCs) contribute to liver regeneration during chronic damage and are implicated as cells of origin for liver cancers including hepatocellular carcinoma (HCC). The CDKN2A locus, which encodes the tumor suppressors alternate reading frame protein (ARF) and INK4A, was identified as one of the most frequently altered genes in HCC. This study demonstrates that inactivation of CDKN2A enhances tumorigenic transformation of LPCs. The level of ARF and INK4A expression was determined in a panel of transformed and nontransformed wild-type LPC lines. Moreover, the transforming potential of LPCs with inactivated CDKN2A was shown to be enhanced in LPCs derived from Arf^-/- and CDKN2A^fl/fl mice and in wild-type LPCs following CRISPR-Cas9 suppression of CDKN2A. ARF and INK4A abundance is consistently reduced or ablated following LPC transformation. Arf^-/- and CDKN2A^-/- LPCs displayed hallmarks of transformation such as anchorage-independent and more rapid growth than control LPC lines with unaltered CDKN2A. Transformation was not immediate, suggesting that the loss of CDKN2A alone is insufficient. Further analysis revealed decreased p21 expression as well as reduced epithelial markers and increased mesenchymal markers, indicative of epithelial-to-mesenchymal transition, following inactivation of the CDKN2A gene were required for tumorigenic transformation. Loss of ARF and INK4A enhances the propensity of LPCs to undergo a tumorigenic transformation. As LPCs represent a cancer stem cell candidate, identifying CDKN2A as a driver of LPC transformation highlights ARF and INK4A as viable prognostic markers and therapeutic targets for HCC.

Childhood adrenocortical tumor: A clinical and immunohistochemical study of 13 cases

The aim of the study was to investigate the molecular mechanisms in childhood adrenocortical tumors (ACTs), which is still unclear.A total of 9 girls and 4 boys with ACTs were enrolled. Relevant clinical features were obtained from records. Immunohistochemistry of vimentin, chromogranin A, S100, synaptophysin, cytokeratin (CK), type 2 3β-hydroxysteroid dehydrogenase (3βHSD), cytochrome P45017α, p53, p21, p27, cyclin D1, Ki-67, insulin growth facter-2 (IGF-2), and β-catenin were undertaken for 13 tumors and 3 adjacent normal tissues. TP53 mutations in exon 2-11 were analyzed for 6 tumors and 3 blood samples.Virilization was the most common presentation (8/13, 61.5%). Immunohistochemically, p53 was positive in 8 of 13 ACTs and none in controls while p21 was positive in 12 of 13 ACTs and none in controls (P = .0036). Ki-67 was positive in 10 of 13 ACTs, but not in normal tissues (P = .0089). Although the expression of p27, cyclin D1, IGF-2 and β-catenin were similar between the ACTs and controls, β-catenin was noted in nuclear of 3 ACTs but not in controls. The difference of type 2 3βHSD and P450c17α was not significant (P > .05, respectively). Four variants of TP53 were identified in the 6 tumors. C215G variant was found in 5 of 6 while A701G and G743A variants were found in 1 case, respectively. A novel C680G variant was also noted in 1 case. It was notable that C215G variant was found in the blood mononuclear cell of 3 patients.In conclusion, p53 variant and p21 overexpression, and abnormal β-catenin distribution may be involved in the etiology and mechanism of childhood ACTs.

Fibroblast as a critical stromal cell type determining prognosis in prostate cancer

BACKGROUND

Tumor stroma associates with prostate cancer (PCa) progression, but its specific cellular composition and association to patient survival outcome have not been characterized.

METHODS

We analyzed stromal composition in human PCa using multiplex immunohistochemistry and quantitative, high-resolution image analysis in two retrospective, formalin-fixed paraffin embedded observational clinical cohorts (Cohort I, n = 117; Cohort II, n = 340) using PCa-specific mortality as outcome measurement.

RESULTS

A high proportion of fibroblasts associated with aggressive disease and castration-resistant prostate cancer (CRPC). In a multivariate analysis, increase in fibroblast proportion predicted poor cancer-specific outcome independently in the two clinical cohorts studied.

CONCLUSIONS

Fibroblasts were the most important cell type in determining prognosis in PCa and associated with CRPC. Thus, the stromal composition could be critically important in developing diagnostic and therapeutic approaches to aggressive prostate cancer.

Intracranial solitary fibrous tumor: Report of two cases

RATIONALE

Intracranial solitary fibrous tumor (ISFT) is a rare spindle cell tumor derived from dendritic mesenchymal cells expressing CD34 antigens, which are widely distributed in human connective tissues.

PATIENT CONCERNS

In two case reports, we describe a 61-year-old woman and a 42-year-old man who present with intracranial malignant SFTs. Computed tomography or magnetic resonance imaging of head revealed that the largest size is about 3.3 × 3.0 cm in left occipital part and 4.0 × 3.0 cm in right skull base.

DIAGNOSIS

Postoperative pathological results demonstrated that all of two cases are SFT. Case one: Immunohistochemical examination demonstrated a strong immunoreaction for cluster of differentiation (CD)34, B-cell lymphoma 2 (Bcl-2) and Vimentin (Vim). Case two: The tumor was distinctively positive for Bcl-2, but not for CD34 and Vim.

INTERVENTIONS

One of the two patients recurred 6 years after the first tumor resection. After the recurrence, two gamma knife treatments were given, and another operation was performed about five years later. In one case, only tumor resection was performed.

OUTCOMES

Case one: The postoperative neurological status was substantially improved and regular follow-up examinations for 6 months postsurgery have shown that the patient is currently disease-free. Case two: The patient achieved a good outcome, with no epilepsy or other neurological symptoms experienced on a regular 6-month follow-up. The patient is currently disease free.

LESSONS

Imaging findings can be used to assist the diagnosis. The diagnostic method is pathology, and total surgical resection is the most effective treatment. The main treatment methods were total resection, supplemented by radiotherapy and chemotherapy if necessary.

Autophagy contributes to hypoxia-induced epithelial to mesenchymal transition of endometrial epithelial cells in endometriosis

Endometriosis is a benign gynecologic disorder, and presents with malignant characteristics, such as migration and invasion. Hypoxia has been implicated in triggering epithelial-mesenchymal transition (EMT). Hypoxia is also known to induce autophagy. However, the relationship between autophagy and EMT under hypoxia conditions in endometriosis remains unknown. In the present study, we found that the expression of hypoxia-inducible factor-1α (HIF-1α), microtubule associated protein light chain 3 (LC3), and mesenchymal cell marker vimentin was significantly higher in ectopic endometrium from patients with endometriosis, along with decreased expression of epithelial cell marker E-cadherin. After hypoxia treatment, endometrial epithelial cells exhibited enhanced migration and invasion abilities, as well as promoted autophagy and the EMT phenotype. Our analyses also show that HIF-1α was responsible for induction of autophagy. Moreover, inhibition of autophagy by chemical or genetic approaches suppressed hypoxia triggered EMT and reduced cell migration and invasion. Collectively, our findings identify that autophagy is critical for the migration and invasion of endometrial cells through the induction of EMT and indicate that inhibition of autophagy may be a novel useful strategy in the treatment of endometriosis.

LncRNA H19/miR-29b-3p/PGRN Axis Promoted Epithelial-Mesenchymal Transition of Colorectal Cancer Cells by Acting on Wnt Signaling

This investigation was aimed at working out the combined role of lncRNA H19, miR-29b and Wnt signaling in the development of colorectal cancer (CRC). In the aggregate, 185 CRC tissues and corresponding para-carcinoma tissues were gathered. The human CRC cell lines (i.e. HT29, HCT116, SW480 and SW620) and normal colorectal mucosa cell line (NCM460) were also purchased. Si-H19, si-NC, miR-29b-3p mimics, miR-29b-3p inhibitor, si-PGRN and negative control (NC) were, respectively, transfected into the CRC cells. Lucif-erase reporter plasmids were prepared to evaluate the transduction activity of Wnt/β-catenin signaling pathway, and dual-luciferase reporter gene assay was arranged to confirm the targeted relationship between H19 and miR-29b-3p, as well as between miR-29b-3p and PGRN. Finally, the proliferative and invasive capacities of CRC cells were appraised through transwell, MTT and scratch assays. As a result, over-expressed H19 and down-expressed miR-29b-3p displayed close associations with the CRC patients' poor prognosis (P < 0.05). Besides, transfection with si-H19, miR-29b-3p mimic or si-PGRN were correlated with elevated E-cadherin expression, decreased snail and vimentin expressions, as well as less-motivated cell proliferation and cell metastasis (P < 0.05). Moreover, H19 was verified to directly target miR-29b-3p based on the luciferase reporter gene assay (P < 0.05), and miR-29b-3p also bound to PGRN in a direct manner (P < 0.05). Finally, addition of LiCl (Wnt/β-catenin pathway activator) or XAV93920 (Wnt/β-catenin pathway inhibitor) would cause remarkably altered E-cadherin, c-Myc, vimentin and snail expressions, as well as significantly changed transcriptional activity of β-catenin/Tcf reporter plasmid (P < 0.05). In conclusion, the lncRNA H19/miR-29b-3p/PGRN/Wnt axis counted a great deal for seeking appropriate diagnostic biomarkers and treatment targets for CRC.

The role of intermediate filaments in maintaining integrity and function of intestinal epithelial cells after massive bowel resection in a rat

PURPOSE

Intermediate filaments (IFs) are a part of the cytoskeleton that extend throughout the cytoplasm of all cells and function in the maintenance of cell-shape by bearing tension and serving as structural components of the nuclear lamina. In normal intestine, IFs provide a tissue-specific three-dimensional scaffolding with unique context-dependent organizational features. The purpose of this study was to evaluate the role of IFs during intestinal adaptation in a rat model of short bowel syndrome (SBS).

MATERIALS AND METHODS

Male rats were divided into two groups: Sham rats underwent bowel transection and SBS rats underwent a 75% bowel resection. Parameters of intestinal adaptation, enterocyte proliferation and apoptosis were determined 2 weeks after operation. Illumina's Digital Gene Expression (DGE) analysis was used to determine the cytoskeleton-related gene expression profiling. IF-related genes and protein expression were determined using real-time PCR, Western blotting and immunohistochemistry.

RESULTS

Massive small bowel resection resulted in a significant increase in enterocyte proliferation and concomitant increase in cell apoptosis. From the total number of 20,000 probes, 16 cytoskeleton-related genes were investigated. Between these genes, only myosin and tubulin levels were upregulated in SBS compared to sham animals. Between IF-related genes, desmin, vimentin and lamin levels were down-regulated and keratin and neurofilament remain unchanged. The levels of TGF-β, vimentin and desmin gene and protein were down-regulated in resected rats (vs sham animals).

CONCLUSIONS

Two weeks following massive bowel resection in rats, the accelerated cell turnover was accompanied by a stimulated microfilaments and microtubules, and by inhibited intermediate filaments. Resistance to cell compression rather that maintenance of cell-shape by bearing tension are responsible for contraction, motility and postmitotic cell separation in a late stage of intestinal adaptation.

MiR-181a promotes epithelial to mesenchymal transition of prostate cancer cells by targeting TGIF2

OBJECTIVE

Prostate cancer is the most commonly diagnosed cancer, and metastatic prostate cancer often leads to poor outcomes for patients. During the metastasis processes, cancer cells acquire a migratory and invasive phenotype. Epithelial to mesenchymal transition (EMT) has been implicated in multiple processes of prostate cancer development including migration, chemoresistance, and carcinogenesis.

PATIENTS AND METHODS

Expressions of miR-181a in prostate tumor samples and cancer cells were measured by qRT-PCR. Epithelial or mesenchymal markers were detected by Western blot. Nuclear translocation of Smad 2/3 was measured by immunostaining of prostate cancer cells.

RESULTS

In this study, we report an oncogenic role of microRNA-181a in prostate cancer cells and patients. MiR-181a is upregulated in metastatic prostate tumor samples compared with primary prostate tumors. Interestingly, we found that overexpression of miR-181a promotes prostate cancer cell migration and invasion. Moreover, we observed that overexpression of miR-181a contributes to an epithelial to mesenchymal transition phenotype in prostate cancer cells: the epithelial marker, E-cadherin was downregulated, and mesenchymal markers, N-cadherin, vimentin, and snail were upregulated. Consistently, the phosphorylation of Smad 2/3 and the nuclear localization of Smad 2/3 were increased by miR-181a expression. We identified that TGIF2 - a repressor of the Smad pathway - is a direct target of miR-181a in prostate cancer cells. Importantly, restoration of TGIF2 in miR-181a overexpressing prostate cancer cells inhibited the Smad pathway and EMT processes.

CONCLUSIONS

This research identifies a molecular mechanism for microRNA-mediated cancer metastasis and improvement novel therapeutic avenue for metastatic prostate cancer patient treatments.

CPEB4 promotes cell migration and invasion via upregulating Vimentin expression in breast cancer

Cytoplasmic polyadenylation element binding protein 4 (CPEB4) is a member of CPEB family which is overexpressed in variety of cancers. However, the biological role and regulatory mechanism of CPEB4 in cancers remain unknown. Here, we first investigate the role of CPEB4 in breast cancer progression and metastasis. The expression of CPEB4 is elevated in breast cancer tissues compared with adjacent normal tissues. Furthermore, high expression levels of CPEB4 is associated with tumor metastasis in breast cancer patients. Ectopic expression of CPEB4 dramatically promotes EMT, migration and invasion of breast cancer cells, while silencing CPEB4 expression significantly reduces these events. Mechanically, overexpression of CPEB4 upregulates Vimentin expression and silencing Vimentin expression blocks CPEB4-induced migration and invasion of breast cancer cells. These results implicate the potential role of CPEB4 and Vimentin in breast cancer metastasis, which is further confirmed by the finding that there is a physical interaction between the two proteins. Altogether, our results provide a novel insight into CPEB4 in regulating breast cancer progression and metastasis.

Cx32 reverses epithelial-mesenchymal transition in doxorubicin-resistant hepatocellular carcinoma

Recently, epithelial-mesenchymal transition (EMT) has been reported to be an important mechanism of drug resistance in numerous types of cancer cells, including hepatocellular carcinoma (HCC). However, the underlying mechanisms remain to be fully elucidated. Connexin (Cx)32 plays a crucial role in hepatocarcinogenesis. The present study investigated the role of Cx32 in the regulation of chemotherapy-induced EMT in HCC. We found that the expression levels of Cx32 and E-cadherin were clearly decreased in HCC tissues compared with the corresponding paracancerous tissues, while the expression level of vimentin was significantly enhanced in HCC tissues. The expression of Cx32 had a strong correlation with the expression of E-cadherin and vimentin. In an in vitro study, a doxorubicin (DOX)-resistant liver cell line HepG2/DOX was established from parental HepG2 cells. The results showed that HepG2/DOX cells acquired EMT characteristics, with a decreased expression level of E-cadherin and an enhanced expression level of vimentin, and possessed high migratory abilities and invasiveness. Meanwhile, Cx32 was significantly decreased in the HepG2/DOX cells. Knockdown of Cx32 by shRNA in HepG2 cells induced EMT, while overexpression of Cx32 converted EMT to mesenchymal-epithelial transition (MET) in the HepG2/DOX cells. These results suggest that Cx32 is an important regulator of DOX-induced EMT in HCC. Cx32 could be considered as a novel target to reverse DOX resistance in HCC.

Differential expression and distribution of cytokeratins and vimentin in buccal pouch mucosal cells during real-time cell proliferation: research based on a porcine model

In recent years, buccal pouch oral mucosa cells were used as a source of potential biological grafting material in advanced tissue engineering. However, there are several limitations in the process of graft fabrication: donor and recipient patient availability as well as an incomplete knowledge of in vitro procedures related to tissue surgical recovery, in vitro cell culture (IVC) and/or tissue processing in “human somatic cell therapy.” Therefore, the animal model for oral mucosa grafting is still recognized as a source for xenografts and a useful model for biomedical research. In this study, the porcine buccal pouch oral mucosa cells were used in analysis of the stromalization/epithelialization process during short-term, in vitro real-time cell proliferation. We evaluated cytokeratin 18 (CK18), cytokeratin 8 + 18 + 19 (panCK), and vimentin (Vim) expression as epithelial and stromal cell markers, respectively. The porcine buccal pouch oral mucosa cells were cultured in vitro for 168 h, and the protein expression/ distribution was analyzed every 24 h during real-time cell proliferation. In our analysis of protein expression using fluorescence intensity (FI), followed by confocal microscopic observations, we found the highest expression of CK18 occurred after 24 h of IVC, panCK after 72 h, and Vim after 48 h of IVC, as compared to other cultivation periods. We also found a substantial increase in Vim expression (3-4 fold) as compared to CK18 and panCK, and all of the investigated proteins were distributed in the cellular cytoplasm. The lag phase of cell proliferation occurred during the first 24 h of IVC, whereas the log phase was observed between 24 h-120 h of IVC. Throughout 7 days of IVC, statistically significant differences were found in Cell Index (CI) of the analyzed cells. Increased Vim expression in buccal pouch oral mucosa cells, as compared to CK18 and panCK, suggested that the stromal cells substantially predominated during in vitro cell cultivation. This may be a result of significant specificity of porcine oral mucosa cells isolated from the buccal pouch.

Mechanisms involved in methylmercuric chloride (MeHgCl)-induced suppression of human neutrophil apoptosis

We have previously demonstrated that concentrations of 1-10 μM of methylmercuric chloride (MeHgCl) that are cytotoxic to monocytes-macrophages can curiously inhibit neutrophil apoptosis by a yet unknown mechanism. In the present study, we demonstrate that, as with the cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF), a classical inhibitor of neutrophil apoptosis, treatment of cells with 5 M MeHgCl inducesde novo protein synthesis and prevents the loss of expression of the antiapoptotic Mcl-1 protein. The expression of the cytoskeletal proteins gelsolin, paxillin and vinculin was similar in MeHgCl or GM-CSF-induced suppression of apoptosis. However, MeHgCl prevents the degradation of vimentin differently than GM-CSF. Apoptosis was further confirmed by flow cytometry (FITC annexin-V), and by monitoring CD16 cell surface expression. Curiously, unlike GM-CSF, MeHgCl did not prevent CD16 shedding. We conclude that, like GM-CSF, MeHgCl can delay neutrophil apoptosis by inducing de novoprotein synthesis and by preventing the loss of the antiapoptotic Mcl-1 protein. However, unlike GM-CSF, MeHgCl induces an atypical degradation of vimentin without preventing CD16 shedding.

Epithelialization and stromalization of porcine follicular granulosa cells during real-time proliferation - a primary cell culture approach

The process of oocyte growth and development takes place during long stages of folliculogenesis and oogenesis. This is accompanied by biochemical and morphological changes, occurring from the preantral to antral stages during ovarian follicle differentiation. It is well known that the process of follicle growth is associated with morphological modifications of theca (TCs) and granulosa cells (GCs). However, the relationship between proliferation and/or differentiation of porcine GCs during long-term in vitro culture requires further investigation. Moreover, the expression of cytokeratins and vimentin in porcine GCs, in relation to real-time cell proliferation, has yet to be explored. Utilizing confocal microscopy, we analyzed cytokeratin 18 (CK18), cytokeratin 8 + 18 + 19 (panCK), and vimentin (Vim) expression, as well as their protein distribution, within GCs isolated from slaughtered ovarian follicles. The cells were cultured for 168 h with protein expression and cell proliferation index analyzed at 24-h intervals. We found the highest expression of CK18, panCK, and Vim occurred at 120 h of in vitro culture (IVC) as compared with other experimental time intervals. All of the investigated proteins displayed cytoplasmic distribution. Analysis of real-time cell proliferation revealed an increased cell index after the first 24 h of IVC. Additionally, during each period between 24-168 h of IVC, a significant difference in the proliferation profile, expressed as the cell index, was also observed. We concluded that higher expression of vimentin at 120 h of in vitro proliferation might explain the culmination of the stromalization process associated with growth and domination of stromal cells in GC culture. Cytokeratin expression within GC cytoplasm confirms the presence of epithelial cells as well as epithelial-related GC development during IVC. Moreover, expression of both cytokeratins and vimentin during short-term culture suggests that the process of GC proliferation is also highly associated with porcine ovarian follicular granulosa cell differentiation in vitro.

Immunohistochemical Characterization of Cloned Lamb Nephropathy

Kidneys from lambs derived by nuclear transfer are frequently abnormal and are characterized by an enlarged pelvis and narrow medulla, consistent with lower urinary tract obstruction and development of variable hydronephrosis. The precise pathogenesis of this entity is unknown. Immunohistochemical staining for intermediate filaments was used to further characterize the lesions seen in this condition and was compared with age-matched control tissue. Major findings were upregulation of cytokeratin on damaged tubules, desmin and vimentin in undifferentiated mesenchyme, and smooth muscle actin in mesenchyme and on smooth muscle “collars” around dilated tubules. In addition, some cases showed reexpression of vimentin and desmin on proximal tubular epithelial cells. Taken together, these findings provide a valuable database for tracking the expression of intermediate filaments throughout renal development in sheep and have further characterized the nature of the response to injury by the developing kidney, a response that is characterized by proliferation of mesenchyme and both reexpression and upregulation of intermediate filaments within renal cells. In addition, the study has confirmed that the changes in cloned lamb nephropathy are established by day 85 of development.

Janus kinases and Src family kinases in the regulation of EGF-induced vimentin expression in MDA-MB-468 breast cancer cells

Epithelial-mesenchymal transition (EMT) is an important process associated with the metastasis of breast cancer cells. Members of the Janus kinases (JAKs) and Src family kinases (SFKs) are implicated in the regulation of an invasive phenotype in various cancer cell types. Using the pharmacological inhibitors JAK Inhibitor I (a pan-JAK inhibitor) and PP2 we investigated the role of the JAKs and SFKs, respectively, in the regulation of EMT markers in the MDA-MB-468 breast cancer cell line model of epidermal growth factor (EGF)-induced EMT. We identified selective inhibition of EGF induction of the mesenchymal marker vimentin by PP2 and JAK Inhibitor I. The effect of JAK Inhibitor I on vimentin protein induction occurred at a concentration lower than that required to significantly inhibit EGF-mediated signal transducer and activator of transcription 3 (STAT3)-phosphorylation, suggesting involvement of a STAT3-independent mechanism of EGF-induced vimentin regulation by JAKs. Despite our identification of a role for the JAK family in EGF-induced vimentin protein expression, siRNA-mediated silencing of each member of the JAK family was unable to phenocopy pharmacological inhibition, indicating potential redundancy among the JAK family members in this pathway. While SFKs and JAKs do not represent global regulators of the EMT phenotype, our findings have identified a role for members of these signaling pathways in the regulation of EGF-induced vimentin expression in the MDA-MB-468 breast cancer cell line.

Twist1 regulates the epithelial-mesenchymal transition via the NF-κB pathway in papillary thyroid carcinoma

Expression of the oncogene Twist1 is correlated with tumor development and metastasis. Recent studies have suggested that the epithelial-to-mesenchymal transition (EMT) is necessary for tumor progression and metastases. Little is known concerning the role of Twist1 and EMT in thyroid cancer. In the present work, the expression levels of Twist1 and one marker of EMT, vimentin, were measured in papillary thyroid carcinoma (PTC). The results showed Twist1 expression to be correlated only with cancer lymph node metastases (P = 0.004) and not with other clinicopathological indicators. Moreover, Twist1 expression was positively correlated with the expression of vimentin (r = 0.408, P = 0.003). In vitro studies further indicated that reducing Twist1 expression using short hairpin RNA against Twist1 can decrease the invasive and metastatic properties of PTC cells and that the down-regulation of Twist1 can reverse EMT by increasing the expression of E-cadherin and down-regulating the expression of vimentin in the PTC cell line IHH-4. To investigate the effects on Twist1, the PTC cell lines TPC-1 and BCPAP were treated with TNF-α, resulting in Twist1 up-regulation that was dependent on NF-κB activation. After the inhibition of NF-κB activity with Bay11-7082, the Twist1 mRNA and protein levels could not be increased. The decline in the Twist1 mRNA and protein levels rendered the cancer cells less invasive. Thus, we conclude that Twist1 plays an important role in the EMT of PTC via the NF-κB pathway.

A Simple Method for Labeling Human Embryonic Stem Cells Destined to Lose Undifferentiated Potency

Mitochondrial oxidative phosphorylation is a major source of cellular ATP. Its usage as an energy source varies, not only according to the extracellular environment, but also during development and differentiation, as indicated by the reported changes in the flux ratio of glycolysis to oxidative phosphorylation during embryonic stem (ES) cell differentiation. The fluorescent probe JC-1 allows visualization of changes in the mitochondrial membrane potential produced by oxidative phosphorylation. Strong JC-1 signals were localized in the differentiated cells located at the edge of H9 ES colonies that expressed vimentin, an early differentiation maker. The JC-1 signals were further intensified when individual adjacent colonies were in contact with each other. Time-lapse analyses revealed that JC-1-labeled H9 cells under an overconfluent condition were highly differentiated after subculture, suggesting that monitoring oxidative phosphorylation in live cells might facilitate the prediction of induced pluripotent stem cells, as well as ES cells, that are destined to lose their undifferentiated potency.

CPEB4 interacts with Vimentin and involves in progressive features and poor prognosis of patients with astrocytic tumors

Cytoplasmic polyadenylation element binding protein 4 (CPEB4) is a regulator of gene transcription and has been reported to be associated with biological malignancy in cancers. However, it is unclear whether CPEB4 has any clinical significance in patients with astrocytic tumors, and mechanisms that CPEB4 contribute to progression of astrocytic tumors remain largely unknown. Here, correlation between CPEB4 expression and prognosis of patients with astrocytic tumors were explored by using qPCR, WB and IHC, and X-tile, SPSS software. Cell lines U251 MG and A172 were used to study CPEB4's function and mechanisms. Co-immunoprecipitation, mass spectrometry, immunofluorescent assay, and western blot were performed to observe the interaction between CPEB4 and Vimentin. CPEB4 mRNA and protein levels were markedly elevated in 12/12 astrocytic tumors in comparison to paratumor. High expression of CPEB4 was significantly correlated with clinical progressive futures and work as an independent adverse prognostic factor for overall survival of patients with astrocytic tumors (relative risk 4.5, 95 % CI 2.1-11.2, p = 0.001). Moreover, knockdown of CPEB4 in astrocytic tumor cells inhibited their proliferation ability , clonogenicity, and invasiveness. Five candidate proteins, GRP78, Mortalin, Keratin, Vimentin, and β-actin, were identified, and the interaction between CPEB4 and Vimentin was finally confirmed. Downregulation of CPEB4 could reduce the protein expression of Vimentin. Our studies first validated that CPEB4 interacts with Vimentin and indicated that high CPEB4 expression in astrocytic tumors correlates closely with a clinically aggressive future, and that CPEB4 might represent a valuable prognostic marker for patients with astrocytic tumors.

The intrinsic stiffness of human trabecular meshwork cells increases with senescence

Dysfunction of the human trabecular meshwork (HTM) plays a central role in the age-associated disease glaucoma, a leading cause of irreversible blindness. The etiology remains poorly understood but cellular senescence, increased stiffness of the tissue, and the expression of Wnt antagonists such as secreted frizzled related protein-1 (SFRP1) have been implicated. However, it is not known if senescence is causally linked to either stiffness or SFRP1 expression. In this study, we utilized in vitro HTM senescence to determine the effect on cellular stiffening and SFRP1 expression. Stiffness of cultured cells was measured using atomic force microscopy and the morphology of the cytoskeleton was determined using immunofluorescent analysis. SFRP1 expression was measured using qPCR and immunofluorescent analysis. Senescent cell stiffness increased 1.88±0.14 or 2.57±0.14 fold in the presence or absence of serum, respectively. This was accompanied by increased vimentin expression, stress fiber formation, and SFRP1 expression. In aggregate, these data demonstrate that senescence may be a causal factor in HTM stiffening and elevated SFRP1 expression, and contribute towards disease progression. These findings provide insight into the etiology of glaucoma and, more broadly, suggest a causal link between senescence and altered tissue biomechanics in aging-associated diseases.

Comparative Label-Free Mass Spectrometric Analysis of Mildly versus Severely Affected mdx Mouse Skeletal Muscles Identifies Annexin, Lamin, and Vimentin as Universal Dystrophic Markers

The primary deficiency in the membrane cytoskeletal protein dystrophin results in complex changes in dystrophic muscles. In order to compare the degree of secondary alterations in differently affected subtypes of skeletal muscles, we have conducted a global analysis of proteome-wide changes in various dystrophin-deficient muscles. In contrast to the highly degenerative mdx diaphragm muscle, which showed considerable alterations in 35 distinct proteins, the spectrum of mildly to moderately dystrophic skeletal muscles, including interosseus, flexor digitorum brevis, soleus, and extensor digitorum longus muscle, exhibited a smaller number of changed proteins. Compensatory mechanisms and/or cellular variances may be responsible for differing secondary changes in individual mdx muscles. Label-free mass spectrometry established altered expression levels for diaphragm proteins associated with contraction, energy metabolism, the cytoskeleton, the extracellular matrix and the cellular stress response. Comparative immunoblotting verified the differences in the degree of secondary changes in dystrophin-deficient muscles and showed that the up-regulation of molecular chaperones, the compensatory increase in proteins of the intermediate filaments, the fibrosis-related increase in collagen levels and the pathophysiological decrease in calcium binding proteins is more pronounced in mdx diaphragm as compared to the less severely affected mdx leg muscles. Annexin, lamin, and vimentin were identified as universal dystrophic markers.

Epstein-Barr virus latent antigens EBNA3C and EBNA1 modulate epithelial to mesenchymal transition of cancer cells associated with tumor metastasis

Epithelial-mesenchymal transition is an important mechanism in cancer invasiveness and metastasis. We had previously reported that cancer cells expressing Epstein-Barr virus (EBV) latent viral antigens EBV nuclear antigen EBNA3C and/ or EBNA1 showed higher motility and migration potential and had a propensity for increased metastases when tested in nude mice model. We now show that both EBNA3C and EBNA1 can modulate cellular pathways critical for epithelial to mesenchymal transition of cancer cells. Our data confirms that presence of EBNA3C or EBNA1 result in upregulation of transcriptional repressor Slug and Snail, upregulation of intermediate filament of mesenchymal origin vimentin, upregulation of transcription factor TCF8/ZEB1, downregulation as well as disruption of tight junction zona occludens protein ZO-1, downregulation of cell adhesion molecule E-cadherin, and nuclear translocation of β-catenin. We further show that the primary tumors as well as metastasized lesions derived from EBV antigen-expressing cancer cells in nude mice model display EMT markers expression pattern suggesting their greater propensity to mesenchymal transition.

Decreased expression of claudin-3 is associated with a poor prognosis and EMT in completely resected squamous cell lung carcinoma

The deregulation of claudin-3 has been reported to correlate with the invasion and metastasis of various cancers, but little is known about its expression level and the prognostic value in squamous cell lung carcinoma (SqCC). The purpose of this study is to determine the expression levels and the prognostic value of claudin-3 in completely resected SqCC tissues, and the potential underlying mechanism. The protein expression of claudin-3, E-cadherin, β-catenin, and vimentin in the tumor tissues from 103 patients with surgically resected SqCC was examined using immunohistochemistry, western blots, as well as semi-quantitative estimation. The claudin-3 protein level was significantly associated with E-cadherin, β-catenin, and vimentin protein expression. A decreased claudin-3 protein level was significantly correlated with TNM stage, lymph node metastasis, and disease recurrence. Similarly, downregulation of E-cadherin was significantly correlated with lymph node metastasis and disease recurrence. Decreased β-catenin expression also had a significant correlation with disease recurrence. Univariate analyses indicated that the T stage, lymph node metastasis, the TNM stage, and the expression of claudin-3, β-catenin, and vimentin were significant predictors for overall survival (OS). Moreover, multivariate analyses demonstrated that the TNM stage and protein levels of claudin-3, β-catenin, and vimentin were independent predictors for OS of SqCC patients. Claudin-3 plays an important role in the epithelial-mesenchymal transition of SqCC and might be used as a potential prognostic factor for SqCC.

Expression of E-cadherin and vimentin in oral squamous cell carcinoma

The aim of the study is to determine the levels of E-cadherin, vimentin expression in tumor tissues from patients with oral squamous cell carcinoma (OSCC), and the relationship between the expression of E-cadherin, vimentin and epithelial-mesenchymal transition, in order to explore its values for predicting the invasion and metastasis of oral squamous cell carcinoma, short survival of patients in many types of cancer. E-cadherin and vimentin expression of 10 benign and 42 OSCC tumor tissues was examined by immunohistochemical staining. E-cadherin is positively expressed in normal oral mucosa epithelium, but vimentin expression is not found in normal oral mucosa epithelia; the E-cadherin and vimentin were expressed in 26 of 42 (61.9%) and 16 of 42 (38.1%), respectively. No statistically difference was found for E-cadherin and vimentin expression in patients with different age, gender and tumor location, E-cadherin and vimentin expression was significantly associated with lymph node metastasis and tissue location (P<0.05); E-cadherin expression was also significantly associated with tumor stage (P<0.05); there are significantly difference between infiltrative margin and central area in patients with oral squamous cell carcinoma for E-cadherin and vimentin positive expression (P<0.05). E-cadherin and vimentin positive expression was associated with tumor metastasis of oral squamous cell carcinoma. Our study preliminarily confirmed that EMT phenomenon is existed during the development of oral squamous cell carcinoma. Co-evaluation of E-cadherin and vimentin might be a valuable tool for predicting OSCC patient outcome.