Vimentin In Cells Research Articles

Interaction of macrophages and endometrial cells induces epithelial-mesenchymal transition-like processes in adenomyosis.

Adenomyosis is a nonneoplastic condition characterized by the benign invasion of ectopic endometrium into the myometrium. Macrophages play significant roles in epithelial-mesenchymal transition (EMT) and adenomyosis. An EMT associated with adenomyosis has been extensively studied. This study investigated the process by which the interaction of macrophages with endometrial cells induces EMT in Ishikawa cells and epithelial cells of adenomyosis. Specimens were collected after hysterectomy or resection of adenomyosis lesions from women with adenomyosis and curettage from women without adenomyosis or endometriosis. Immunohistochemistry and immunofluorescent staining demonstrated that CD68-positive macrophages aggregated in adenomyosis lesions, along with the increased protein expressions of n-cadherin, vimentin, and S100A4. By contrast, the protein expressions of e-cadherin and CK7 were decreased. After the primary endometrium cells were cocultured with THP-1-derived macrophages, the protein expression levels of n-cadherin, vimentin, and S100A4 of endometrium cells were increased, whereas the protein expression levels of e-cadherin and CK7 were decreased. The proportion of alternatively activated (M2) macrophages derived from THP-1 macrophages was also increased. The M2 macrophages elicited a bidirectional effect on Ishikawa cells by inducing EMT-like or mesenchymal-epithelial transition-like processes. The apoptotic rate of the Ishikawa cells cocultured with macrophages was increased, whereas their cell proliferation rate was decreased. Transmission electron microscopy indicated that the number of intercellular junctions of the cocultured Ishikawa cells was reduced. Microarray-based gene expression analysis revealed that transforming growth factor-β1/Smad3 and interleukin-6/JAK2/STAT3 signaling pathways were upregulated. Therefore, macrophages can induce EMT-like processes in adenomyosis and undergo polarization to M2.

Three-Dimensional Construction of a Rabbit Anterior Corneal Replacement for Lamellar Keratoplasty.

The aim of this study was to construct a rabbit anterior corneal replacement for transplantation using acellular porcine corneal matrix (APCM) and rabbit epithelial or stromal cells. APCM was prepared from fresh porcine cornea treated with 0.5% (wt./vol.) sodium dodecyl sulfate (SDS) solution. The expanded stromal cells were first injected into APCM parallel to its surface and were cultured in a shaking culture system for 7 days to obtain the stromal construct. Next, corneal epithelial cells were cultured on the stromal construct surface for another 7 days to obtain rabbit anterior corneal lamella. The construct had a phenotype similar to that of normal cornea, with high expression of cytokeratin 3 in the epithelial cell layer and vimentin in the stromal cells. More importantly, the construct integrated well with the implanted host corneal tissue, and the implant cornea maintained transparency in the 6-month follow-up, although there was a slight haze in the central corneal area. The endothelium in the surgery cornea had a similar cell density and mosaic pattern with normal cornea as shown by confocal laser corneal microscopy, and the regenerated corneal epithelial cells on the implant surface showed a similar morphology to that of natural epithelial cells. These results demonstrate that the constructed anterior corneal replacement exhibits an excellent biological property for lamellar keratoplasty and might be a possible alternative to human corneal tissue in the future.

β-Lapachone Inhibits Lung Metastasis of Colorectal Cancer by Inducing Apoptosis of CT26 Cells.

Background: β-Lapachone is a quinone-containing compound found in red lapacho (Tabebuia impetiginosa, syn. T avellanedae) trees. Lapacho has been used in traditional medicine by several South and Central American indigenous people to treat various types of cancer. The purpose of this study was to investigate the antimetastatic properties of β-lapachone and the underlying mechanisms using colon cancer cells. Methods: This research used metastatic murine colon cancer cell lines, colon 26 (CT26) and colon 38 (MC38). A WST assay, annexin V assay, cell cycle analysis, wound healing assay, invasion assay, western blot analysis, and real-time reverse transcription–polymerase chain reaction were performed to examine the effects of β-lapachone on metastatic phenotypes and molecular mechanisms. The effect of β-lapachone on lung metastasis was assessed in a mouse experimental metastasis model. Results: We found that the inhibition of proliferation of the colon cancer cell lines by β-lapachone was due to the induction of apoptosis and cell cycle arrest. β-Lapachone induced the apoptosis of CT26 cells through caspase-3, -8, and -9 activation; poly(ADP-ribose) polymerase cleavage; and downregulation of the Bcl-2 family in a dose- and time-dependent manner. In addition, a low concentration of β-lapachone decreased the cell migration and invasion by decreasing the expression of matrix metalloproteinases-2 and -9, and increased the expression of tissue inhibitors of metalloproteinases-1 and -2. Moreover, β-lapachone treatment regulated the expression of epithelial-mesenchymal transition markers such as E- and N-cadherin, vimentin, β-catenin, and Snail in CT26 cells. In the mouse experimental metastasis model, β-lapachone significantly inhibited the lung metastasis of CT26 cells. Conclusions: Our results demonstrated the inhibitory effect of β-lapachone on colorectal lung metastasis. This compound may be useful for developing therapeutic agents to treat metastatic cancer.

Microcystin-LR promotes epithelial-mesenchymal transition in colorectal cancer cells through PI3-K/AKT and SMAD2

Increasing evidences suggest that microcystins, a kind of toxic metabolites, produced by cyanobacteria in contaminated water may contribute to the aggravation of the human colorectal carcinoma. Our previous study showed that microcystin-LR (MC-LR) exposure caused significant invasion and migration of colorectal cancer cells. However, the roles of MC-LR in regulating epithelial-mesenchymal transition (EMT) in colorectal cancer cells remain unknown. In our study, we observed that MC-LR treatment decreased epithelial marker E-cadherin expression and up-regulated the levels of mesenchymal markers Vimentin and Snail in colorectal cancer cells. Moreover, MC-LR stimulated protein expression of SMAD2 and phospho-SMAD2 by PI3-K/AKT activation. The activated PI3-K/AKT and SMAD2 signaling largely accounted for MC-LR-induced EMT, which could be reversed by SMAD2 RNA interference or PI3-K/AKT chemical inhibitor in colorectal cancer cells. Our results show that MC-LR could induce SMAD2 expression to promote colorectal cancer cells EMT, which not only provides a mechanistic insight on MC-LR promotes EMT in colorectal cancer cells, but also support to the development of therapies aimed at SMAD2 in colorectal cancer induced by MC-LR.

Leukotriene B4 induces EMT and vimentin expression in PANC-1 pancreatic cancer cells: Involvement of BLT2 via ERK2 activation

Leukotriene B4 (LTB4) is a leukocyte chemoattractant and plays a major role controlling inflammatory responses including pancreatitis. LTB4 is known to be correlated with cancer progression. LTB4 induces keratin phosphorylation and reorganization by activating extracellular regulated kinase (ERK) in PANC-1 pancreatic cancer cell lines. However, the role of LTB4 in epithelial mesenchymal transition (EMT) and vimentin expression in pancreatic cancer cells is unknown.We examined whether LTB4 induces EMT and vimentin expression by Western blot, si-RNA, and RT-PCR. LTB4 induced morphological change, decreased E-cadherin expression and increased N-cadherin and vimentin expression. LTB4 increased migration and invasion of PANC-1 cancer cells. LTB4 dose-dependently upregulated expression of vimentin in PANC-1 cancer cells. LTB4-induced vimentin expression was suppressed by LY255283 (BLT2 antagonist). Comp A, a BLT2 agonist, further increased vimentin expression. Gene silencing of BLT2 suppressed LTB4-or Comp A-induced vimentin expression in PANC-1 cells. The MEK inhibitor, PD98059 suppressed Comp A-induced vimentin expression. Comp A or transfection of plasmid containing BLT2 cDNA (pCBLT2) activated ERK, and BLT2 gene silencing suppressed Comp A-induced ERK activation. ERK2 siRNA abrogated Comp A-induced vimentin expression and ERK2 overexpression enhanced vimentin expression. One of well-known cause of ras mutation, cigarette smoke extracts increased BLT2 expression in PANC-1 cancer cells.Taken together, these results suggest that BLT2 is involved in LTB4-induced vimentin expression through ERK2 in PANC-1 cells.

ADAM17 promotes epithelial-mesenchymal transition via TGF-β/Smad pathway in gastric carcinoma cells.

Although a disintegrin and metalloproteinase-17 (ADAM17) overexpression has been demonstrated in numerous human tumors including gastric cancer, its role in gastric cancer development remains to be clarified. In the present study, we identify that ADAM17 activates TGF-β/Smad signaling to promote epithelial-mesenchymal transition (EMT) in gastric cancer cells. We found that ADAM17 promotes proliferation, migration and invasion in gastric carcinoma cells. Subsequently, we revealed that silencing ADAM17 induces the expression of epithelial marker of E-cadherin and downregulates expression of mesenchymal markers including N-cadherin, vimentin and Snail in MGC803 and MKN45 cells, whereas ADAM17 overexpression reverses these changes in BGC823 and HGC27 cells. Furthermore, ADAM17 knockdown significantly inhibits the expression of TGF-β and its downstream signaling molecules p-Smad2 and p-Smad3 in MGC803 and MKN45 cells. Consistently, ADAM17 overexpression reversed these changes in BGC823 and HGC27 cells. These results suggest that ADAM17 promotes epithelial-mesenchymal transition via the TGF-β/Smad pathway. Collectively, the present study demonstrates that ADAM17 plays a critical role in the development of gastric cancer and provides a potential therapeutic target for gastric cancer.

Spindle cell lipoma adherent to the digital nerve in the palm.

Dear sir, Spindle cell lipoma, a solitary, slowly growing subcutaneous tumor, mainly in the posterior neck, shoulder girdle, upper back predominantly in men in the fifth to seventh decades. It can arise in other areas of the body. Johnson et al. reported a spindle cell lipoma in the orbital region; Toker et al. reported in the breast; Suster et al. reported in the gastrointestinal tract and Eckert et al. reported in the upper arm. Spindle cell lipomas are typically placed encapsulated in sub cutis, while occasionally they are poorly demarcated and can extend in to the dermis or underlying tissues. No case of spindle cell lipoma in the palm adherent to digital nerve has been reported in the literature. Here, we present a rare case of spindle cell lipoma adherent to the digital nerve in the palm. A 43 years old male patient was admitted to our clinic for further examination of the mass occurring in his right palm 24 months ago and hypoesthesia of radial side of the third finger for 3 months. A physical examination revealed 4 cm × 3 cm subcutaneous mass in the right palmar area. Ultrasonography revealed well circumscribed and low-echo 4 cm × 3 cm mass in the subcutaneous region of the palm. Furthermore, heterogenous signal intensity on all pulse sequences was showed by magnetic resonance imaging. A fine needle biopsy reported a spindle cell lipoma. At exploration, there was a well-circumscribed mass, connected to the digital nerve. (Fig.​(Fig.1a)1a) The multi lobulated 34 mm diameter mass was yellowish-white on its cut surfaces, had a firm texture, and was clearly demarcated from the adjacent tissues by a thin fibrous capsule The patient had no recurrence in 46 months follow-up. Fig. 1 a. Peroperative view of the spindle cell lipoma and the digital nerve b. Spindle cells in non-lipogenic areas are CD34 positive. (CD34; Original magnification X200) Spindle cell lipoma is a benign tumor distinguished by the replacement of mature adipocoyte by collagen forming spindle cells. It is a mixture of short spindle cells, adipocytes, and ropey collagen bundles, sometimes with a myxoid stroma. The differential diagnosis includes dermatofibrosarcoma protuberance, angiomyofibroblastoma, nodular fasciitis and myxoid liposarcoma [1]. Lipoblasts, fat necrosis, and fat with atrophic changes are important to the differential diagnosis of liposarcoma and spindle cell lipoma. There was co-expression of CD34, bcl-2, and vimentin in the spindle cells. (Fig. 1b). Tardio also reported that co-expression of CD34 and bcl-2 was common in atypical adipocytic tumors in a recent study [2]. Spindle cell lipoma is most closely related to pleomorphic lipoma in terms of demographics and presenting location. Cytogenetically, most spindle cell and pleomorphic lipomas show common 16q or 13q abnormalities [3]. Some authors have reported on the intra dermal origin which presents with different clinical or morphological features such as, widespread anatomical distribution, female predilection and an infiltrative pattern. Also, Mounasamy et al. have reported single case of spindle cell lipoma of palm [4]. Definitive diagnosis of spindle cell lipoma is crucial to recognize that this is a benign tumor and avoid misdiagnosing the lesion as a myxoid liposarcoma. The treatment of option for spindle cell lipoma is a complete local excision and its recurrence is extremely rare.

Alpha1-Antitrypsin Attenuates Renal Fibrosis by Inhibiting TGF-β1-Induced Epithelial Mesenchymal Transition

Alpha1-antitrypsin (AAT) exerts its anti-inflammatory effect through regulating the activity of serine proteinases. This study evaluated the inhibitory effects of AAT against the transforming growth factor (TGF)-β1 induced epithelial-to-mesenchymal transition (EMT) in unilateral ureter obstruction (UUO) mice and Madin-Darby canine kidney (MDCK) cells. C57BL/6 mice with induced UUO were injected intraperitoneally with AAT (80 mg/Kg) or vehicle for 7 days. MDCK cells were treated with TGF-β1 (2 ng/mL) for 48 hours to induce EMT, and co-treated with AAT (10 mg/mL) to inhibit the EMT. Masson’s trichrome and Sirius red staining was used to estimate the extent of renal fibrosis in UUO mice. The expression of alpha-smooth muscle actin (α-SMA), vimentin, fibronectin, collagen I, and E-cadherin in MDCK cells and kidney tissue were evaluated. Masson’s and Sirius red staining revealed that the area of renal fibrosis was significantly smaller in AAT treated UUO group compared with that of UUO and vehicle treated UUO groups. AAT treatment attenuated upregulation of Smad2/3 phosphorylation in UUO mouse model. Co-treatment of MDCK cells with TGF-β1 and AAT significantly attenuated the changes in the expression of α-SMA, vimentin, fibronectin, collagen I, and E-cadherin. AAT also decreased the phosphorylated Smad3 expression and the phosphorylated Smad3/Smad3 ratio in MDCK cells. AAT treatment inhibited EMT induced by TGF-β1 in MDCK cells and attenuated renal fibrosis in the UUO mouse model. The results of this work suggest that AAT could inhibit the process of EMT through the suppression of TGF-β/Smad3 signaling.

Cardamonin, a chalcone, inhibits human triple negative breast cancer cell invasiveness by downregulation of Wnt/β-catenin signaling cascades and reversal of epithelial-mesenchymal transition.

Cardamonin (CD), an active chalconoid, has shown potent anticancer effects in preclinical studies; however, the effect and underlying mechanism of CD for the treatment of triple negative breast cancer (TNBC) is unclear. This study aims to examine the cytotoxic effects of CD and investigate the underlying mechanism in human TNBC cells. The results show that CD exhibits cytotoxicity by inducing apoptosis and cell cycle arrest in TNBC cells via modulation of Bcl-2, Bax, cyt-C, cleaved caspase-3, and PARP. We find that CD significantly increases expression of the epithelial marker E-cadherin, while reciprocally decreasing expression of mesenchymal markers such as snail, slug, and vimentin in BT-549 cells. In parallel with epithelial-mesenchymal transition (EMT) reversal, CD down regulates invasion and migration of BT-549 cells. CD markedly reduces stability and nuclear translocation of β-catenin, accompanied with downregulation of β-catenin target genes. Using the TopFlash luciferase reporter assay, we reveal CD as a specific inhibitor of the Wnt3a-induced signaling. These results suggest the involvement of the Wnt/β-catenin signaling in the CD-induced EMT reversion of BT-549 cells. Notably, CD restores the glycogen synthase kinase-3β (GSK3β) activity, required for β-catenin destruction via the proteasome-mediated system, by inhibiting the phosphorylation of GSK3β by Akt. These occurrences ultimately lead to the blockage of EMT and the invasion of TNBC cells. Further antitumor activity of CD was tested in 4T1 (TNBC cells) induced tumor and it was found that CD significantly inhibited the tumor volume at dose of 5 mg/kg-treated mice. © 2016 BioFactors, 43(2):152-169, 2017.

Trichostatin A Inhibits Epithelial Mesenchymal Transition Induced by TGF-β1 in Airway Epithelium.

Background and ObjectivesTissue remodeling is believed to cause recalcitrant chronic rhinosinusitis (CRS). Epithelial-mesenchymal transition (EMT) is a novel clinical therapeutic target in many chronic airway diseases related with tissue remodeling. The aim of this study was to investigate the effect of trichostatin A (TSA) on transforming growth factor (TGF)-β1-induced EMT in airway epithelium and nasal tissue.Materials and MethodsA549 cells, primary nasal epithelial cells (PNECs), or inferior nasal turbinate organ culture were exposed to TSA prior to stimulation with TGF-β1. Expression levels of E-cadherin, vimentin, fibronectin, α-smooth muscle actin (SMA), histone deacetylase 2 (HDAC2), and HDAC4 were determined by western blotting and/or immunofluorescent staining. Hyperacetylation of histone H2 and H4 by TSA was measured by western blotting. After siHDAC transfection, the effects of HDAC2 and HDAC4 silencing on expression of E-cadherin, vimentin, fibronectin, α-SMA, HDAC2, and HDAC4 in TGF-β1-induced A549 were determined by RT-PCR and/or western blotting. We assessed the change in migration capacity of A549 cells by using cell migration assay and transwell invasion assay.ResultsTGF-β1 altered mRNA and protein expression levels of EMT markers including E-cadherin, vimentin, fibronectin, α-SMA, slug, and snail in A549 cells. Inhibition and silencing of HDAC2 and HDAC4 by TSA and siRNA enhanced TGF-β1-induced EMT in A549 cells. TSA blocked the effect of TGF-β1 on the migratory ability of A549 cells. In experiments using PNECs and inferior turbinate organ cultures, TSA suppressed expression of EMT markers induced by TGF-β1.ConclusionsWe showed that EMT is induced by TGF-β1 in airway epithelial cells and nasal tissue via activation of HDAC2 and HDAC4, and that inhibition of HDAC2 and HDAC4 by TSA reduces TGF-β1-induced EMT. This observation indicates that histone deacetylase inhibitors such as TSA could be potential candidates for treatment of recalcitrant CRS related with tissue remodeling.

Little evidence for epithelial-mesenchymal transition in a murine model of airway fibrosis induced by repeated naphthalene exposure

Recent evidence suggests that epithelial-mesenchymal transition (EMT) is involved in the pathogenesis of airway obstructive diseases, such as chronic obstructive pulmonary disease, asthma and bronchiolitis obliterans syndrome after lung transplantation. However, whether EMT occurs in an experimental model of airway fibrosis is not well known. We explored evidence of EMT in a murine model of airway fibrosis induced by repeated exposure to naphthalene. Mice were administered intraperitoneal injections of naphthalene or corn oil vehicle once weekly for 14 consecutive weeks. The animals were sacrificed 5days after the final injection of naphthalene or corn oil vehicle. EMT was evaluated in lung tissue sections using immunohistochemistry and immunofluorescence. Repeated naphthalene exposure induced loss of club cells, hyperplasia of epithelial cells and peribronchial fibrosis. However, we did not find any loss of E-cadherin expression or any acquisition of vimentin, S100A4 or αSMA in epithelial cells in control or naphthalene-exposed mice. These results suggest that EMT does not contribute significantly to naphthalene-induced airway fibrosis in mice.

Identification and characterization of Xenopus tropicalis common progenitors of Sertoli and peritubular myoid cell lineages.

ABSTRACTThe origin of somatic cell lineages during testicular development is controversial in mammals. Employing basal amphibian tetrapod Xenopus tropicalis we established a cell culture derived from testes of juvenile male. Expression analysis showed transcription of some pluripotency genes and Sertoli cell, peritubular myoid cell and mesenchymal cell markers. Transcription of germline-specific genes was downregulated. Immunocytochemistry revealed that a majority of cells express vimentin and co-express Sox9 and smooth muscle α-actin (Sma), indicating the existence of a common progenitor of Sertoli and peritubular myoid cell lineages. Microinjection of transgenic, red fluorescent protein (RFP)-positive somatic testicular cells into the peritoneal cavity of X. tropicalis tadpoles resulted in cell deposits in heart, pronephros and intestine, and later in a strong proliferation and formation of cell-to-cell net growing through the tadpole body. Immunohistochemistry analysis of transplanted tadpoles showed a strong expression of vimentin in RFP-positive cells. No co-localization of Sox9 and Sma signals was observed during the first three weeks indicating their dedifferentiation to migratory-active mesenchymal cells recently described in human testicular biopsies.

Abstract 1641: Complex behavior of ALDH1A1 and IGFBP1 in liver metastasis of colorectal cancer

Abstract The present study aimed to identify upregulated genes associated with colorectal cancer (CRC) liver metastasis (CLM) using our dataset (GSE50760) previously established by RNA sequencing and to verify their biological behavior. Candidate genes were assessed for their role in tumor proliferation, invasion, and the expression of epithelial-mesenchymal transition/CRC stem cell (EMT/CSC)-related molecules. The role of the identified genes in CLM was verified in mice after intrasplenic transplantation of CRC cells. Of nine candidate genes, ALDH1A1 and IGFBP1 were selected and showed few post-translational changes. The upregulation of ALDH1A1 and IGFBP1 significantly and time-dependently decreased cell proliferation (p ≤ 0.001-0.003) and suppressed invasiveness by ≥3 fold over control cells (p < 0.001) in the SW480 cell line, whereas it had a mild effect on reducing SW620 cell proliferation. EMT/CSC-related molecules showed different patterns of expression in CLM tissues and treated CRC cells. The cadherin switch, namely, N-cadherin upregulation with E-cadherin downregulation, was not observed in CLM tissues and treated CRC cells. Persistent overexpression of β-catenin, vimentin, and ZO-1 in IGFBP1-overexpressing SW480 cells may have contributed to CLM development in mice implanted with IGFBP1-overexpressing cells (CLM occurrences: SW480/IGFBP1 transfected mice vs. SW480/vector and /ALDH1A1 transfected mice, 4/8 vs. 0/10, p = 0.023). ALDH1A1 and IGFBP1 were differentially overexpressed in CLM and may play a dual role, functioning as tumor suppressors and metastasis promoting genes in CRC. Unidentified behaviors of these genes may facilitate the reassessment of their potential value as CLM modulators and as therapeutic targets. Citation Format: Jin Cheon Kim, Ye Jin Ha, Ka Hee Tak, Seon Ae Roh, Chan Wook Kim, Tae Won Kim, Dong-Hyung Cho, Seon-Kyu Kim, Seon-Young Kim, Yong Sung Kim. Complex behavior of ALDH1A1 and IGFBP1 in liver metastasis of colorectal cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1641.

Abstract 717: Monocytic and granulocytic MDSCs display distinct molecular properties and coordinate the dynamic switches between EMT-MET in breast cancer model

Abstract It is widely accepted that the epithelial-mesenchymal plasticity of malignant cells is required during cancer metastatic cascade. The complex phenotypic changes highly depend on the collaboration of various molecular signaling and extracellular cues originating from wide range of stromal cells in the tumor microenvironment. However, the specific mechanisms of how EMT plasticity spatiotemporally regulates metastasis are poorly defined. Myeloid-derived suppressor cells (MDSCs) have been identified in most cancer patients and animal models due to their immune suppressive functions, but recent studies implicate their direct role in promoting metastasis by activating tumor-angiogenesis. To determine the roles of MDSCs in breast cancer metastasis, we utilized murine breast cancer cells, non-metastatic EMT6 and metastatic 4T1 cells. We showed that the metastatic 4T1 murine breast tumors induced early systemic expansion and mobilization of MDSCs in distant sites as well as in the primary tumor. We investigated the direct functions of MDSCs in tumor progression by isolating monocytic and granulocytic MDSCs from primary tumor, lung and bone marrow of tumor-bearing mice and then they were co-cultured with non-metastatic EMT6 cells. We found that tumor infiltrating m-MDSCs from 4T1 tumor-bearing mice increased the expression of Vimentin, Twist1, TGF-â and IL-6 in EMT6 tumor cells. In contrast, flow cytometry sorted lung infiltrating MDSCs from 4T1 tumor-bearing mice enhanced the EpCAM expression and proliferation in EMT6 cells. Cell invasion assay showed that invasive ability of EMT6 cells were significantly increased when they were co-cultured with m-MDSCs while g-MDSCs slightly decreased the number of invaded cells, compared to control group. We utilized immunofluorescence staining and confirmed the increased expression of Vimentin, CK14 (cytokeratin 14) in EMT6 cells co-cultured with m-MDSCs. In contrast, g-MDSCs induced down-regulation of these markers while they increased cell proliferation as assessed by Ki67 staining. Furthermore, flow cytometry analysis showed the increased CD24+CD29+ population, a marker of murine cancer stem cell (CSC) phenotype, in EMT6 cells when co-cultured with m-MDSCs from 4T1 tumor-bearing mice. Tumor sphere assay confirmed that m-MDSCs enhanced sphere forming ability of tumor cells. Taken together, these data suggest that m-MDSCs derived from metastatic 4T1 tumor-bearing mice are able to confer EMT/CSC phenotype on tumor cells while g-MDSCs are more potent in inducing epithelial phenotype and proliferation in tumor cells. Citation Format: Eunmi Lee, Maria Ouzounova, Raziye Piranlioglu, Abdeljabar El Andaloussi, Mehmet Demirci, Ena Novakovic, Alicia Hudson, Sumeyye Korkaya, Gang Zhou, Hasan Korkaya. Monocytic and granulocytic MDSCs display distinct molecular properties and coordinate the dynamic switches between EMT-MET in breast cancer model. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 717.

Abstract 1553: Evaluation of a tubulin, detyrosinated tubulin and vimentin expression in CTCs; identification of the interaction between CTCs and blood cells through cytoskeletal elements

Abstract Background: Circulating tumor cells are the major player in metastatic procedure (CTCs). A potential mechanism of cell migration and invasion is the formation of microtentacles in tumor cells. These structures are supported by alpha-Tubulin, detyrosinated, alpha Tubulin (GLU) and Vimentin. The goal of the current study is to identify the expression of the above cytoskeletal proteins on CTCs. Methods: We used three different representative breast cancer cell lines MCF7, SKBR3 and MDA-MB 231 spiked in of normal donor's blood as controls. Furthermore 15 metastatic breast cancer patients were enrolled in this study. Tumor cell were isolated using the ISET platform. Spots were then stained with two different combinations of antibodies; pancytokeratin/Vimentin/a-Tubulin and pancytokeratin/Vimentin (VIM)/GLU. Cells were then analyzed with both confocal laser scanning microscopy and the ARIOL system. Results: We observed that Vimentin was highly expressed in MDA-MB231 cells whereas lower expression was observed in SKBR3 and MCF7 cells. Fluorescence intensity quantification, using the ARIOL system, revealed that the ratio CK/VIM was 41.11, 29.03 and 4.58 in MCF7, SKBR3 and MDA-MB 231 respectively. CK/Tubulin ratio was also higher in MCF7 compared to other cell lines 6.24, 2.29 and 4.18 respectively. In accordance with this, CK/GLU was 20.13 in MCF7 cells, 11.87 in SKBR3 and 11.68 in MDA-MB 231. Interestingly, in SKBR3 and MDA-MB 231 cell lines, alpha-tubulin and vimentin filaments were observed to mediate tumor to blood cell interaction through filamentous bridges between cells. Consequently, we analyzed 15 breast cancer patients. Eight (53%) of them harvested CTCs in their blood. One of these patients had clusters of CTCs in her blood. In this patient as well as in other CK(+) patients, CTC-to-CTC communication through cystoskeletal bridges could be revealed. These cell connections show localization of alpha-tubulin, Vimentin and GLU; moreover, the same proteins form cytoskeletal structures which allow connections between CTCs and blood cells. In all breast cancer patients the CK/Vimentin and CK/Tubulin ratio was lower than that observed in MCF7 cells. Conversely, there was a heterogeneity of the CK/GLU ratio since in four patients was lower than that of MCF7 cells and in three others higher. Conclusions: The importance of understanding the mechanisms that underlie CTC aggregation have been highlighted by recent reports showing that clusters of CTCs have up to 50-fold higher metastatic potential. Our study shows that CTCs can aggregate with each other and with blood cells through cytoskeletal structures supported by. Vimentin, a-Tubulin and Glu-tubulin. Quantification of these cytoskeletal elements revealed that CTCs present a phenotype similar to the most aggressive cell lines. Citation Format: Galaktea Kallergi, Stuart S. Martin, Panagiotis Katsarlinos, Vassilis Georgoulias. Evaluation of a tubulin, detyrosinated tubulin and vimentin expression in CTCs; identification of the interaction between CTCs and blood cells through cytoskeletal elements. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1553.

Downregulation of vimentin expression increased drug resistance in ovarian cancer cells.

Cisplatin and other platinum-based drugs have been widely used in the treatment of ovarian cancer, but most patients acquire the drug resistance that greatly compromises the efficacy of drugs. Understanding the mechanism of drug resistance is important for finding new therapeutic approaches. In the present study, we found that the expression of vimentin was downregulated in drug-resistant ovarian cancer cell lines A2780-DR and HO-8910 as compared to their respective control cells. Overexpression of vimentin in A2780-DR cells markedly increased their sensitivity to cisplatin, whereas knockdown of vimentin in A2780, HO-8910-PM and HO-8910 cells increased the resistance to cisplatin, demonstrating that vimentin silencing enhanced cisplatin resistance in ovarian cancer cells. Quantitative proteomic analysis identified 95 differentially expressed proteins between the vimentin silenced A2780 cells (A2780-VIM-KN) and the control cells, in which downregulation of endocytic proteins and the upregulation of exocytotic proteins CHMP2B and PDZK1 were proposed to contribute the decreased cisplatin accumulation in vimentin knockdown cells. Silencing of vimentin induced upregulation of cancer stem cell markers and both A2780-DR and A2780-VIM-KN cells were more facile to form spheroids than control cells under serum-free culture condition. Our results also revealed that vimentin knockdown increased the 14-3-3 mediated retention of Cdc25C in the cytoplasm, leading to inactivation of Cdk1 and the prolonged G2 phase arrest that allowed the longer period of time for cells to repair cisplatin-damaged DNA. Taken together, we demonstrated that vimentin silencing enhanced cells' resistance to cisplatin via prolonged G2 arrest and increased exocytosis, suggesting that vimentin is a potential target for treatment of drug resistant ovarian cancer.

Expression of Cell Competition Markers at the Interface between p53 Signature and Normal Epithelium in the Human Fallopian Tube.

There is a growing body of evidence regarding cell competition between normal and mutant mammalian cells, which suggest that it may play a defensive role in the early phase of carcinogenesis. In vitro study in the past has shown that overexpression of vimentin in normal epithelial cells at the contact surface with transformed cells is essential for the cell competition involved in epithelial defense against cancer. In this study, we attempted to examine cell competition in human tissue in vivo by investigating surgically resected human fallopian tubes that contain p53 signatures and serous tubal intraepithelial lesions (STILs), a linear expansion of p53-immunopositive/TP53 mutant tubal epithelial cells that are considered as precursors of pelvic high grade serous carcinoma. Immunofluorescence double staining for p53 and the cell competition marker vimentin was performed in 21 sections of human fallopian tube tissue containing 17 p53 signatures and 4 STILs. The intensities of vimentin expression at the interface between p53-positive cells at the end of the p53 signature/STIL and adjacent p53-negative normal tubal epithelial cells were compared with the background tubal epithelium. As a result, the average vimentin intensity at the interfaces relative to the background intensity was 1.076 (95% CI, 0.9412 – 1.211 for p53 signature and 0.9790 (95% CI, 0.7206 – 1.237) for STIL. Thus, it can be concluded that overexpression of the cell competition marker vimentin are not observed in human tissue with TP53 alterations.

Effects of culture supernatant of human amnion mesenchymal stem cells on biological characteristics of human fibroblasts

To investigate the effects of culture supernatant of human amnion mesenchymal stem cells (hAMSCs-CS) on biological characteristics of human fibroblasts. (1) hAMSCs were isolated from deprecated human fresh amnion tissue of placenta and then sub-cultured. The morphology of hAMSCs on culture day 3 and hAMSCs of the third passage were observed with inverted phase contrast microscope. (2) Two batches of hAMSCs of the third passage were obtained, then the expression of vimentin of cells was observed with immunofluorescence method, and the expression of cell surface marker CD90, CD73, CD105, and CD45 was detected by flow cytometer. (3) hAMSCs-CS of the third passage at culture hour 72 were collected, and the content of insulin-like growth factor Ⅰ (IGF-Ⅰ), vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), and basic fibroblast growth factor (bFGF) were detected by enzyme-linked immunosorbent assay. (4) Human fibroblasts were isolated from deprecated human fresh prepuce tissue of circumcision and then sub-cultured. Human fibroblasts of the third passage were used in the following experiments. Cells were divided into blank control group and 10%, 30%, 50%, and 70% hAMSCs-CS groups according to the random number table (the same grouping method below), with 48 wells in each group. Cells in blank control group were cultured with DMEM/F12 medium containing 2% fetal bovine serum (FBS), while cells in the latter 4 groups were cultured with DMEM/F12 medium containing corresponding volume fraction of hAMSCs-CS and 2% FBS. The proliferation activity of cells was detected by cell counting kit 8 and microplate reader at culture hour 12, 24, 48, and 72, respectively, and corresponding volume fraction of hAMSCs-CS which causing the best proliferation activity of human fibroblasts was used in the following experiments. (5) Human fibroblasts were divided into blank control group and 50% hAMSCs-CS group and treated as in (4), with 4 wells in each group, at post scratch hour (PSH) 0 (immediately after scratch), 12, 24, 48, and 72, the migration distance of cells was observed and measured with inverted phase contrast microscope. (6) Human fibroblasts were grouped and treated as in (5), with 3 battles in each group, and apoptosis rate of cells was detected by flow cytometer. Data were processed with analysis of variance of factorial design, analysis of variance for repeated measurement, one-way analysis of variance, LSD test, and t test. (1) On culture day 3, most hAMSCs were in large form, and spindle-shaped with much prominences like fibroblasts or in flat polygonal shape. hAMSCs of the third passage were spindle-shaped. The expression of vimentin of hAMSCs of the third passage was strongly positive, and the expressions of surface markers CD90, CD73, and CD105 of the cells were positive, while the expression of CD45 of the cells was negative. (2) The content of IGF-Ⅰ, VEGF, EGF, and bFGF in hAMSCs-CS were respectively (11.7±1.0), (316±68), (6.1±0.4), and (1.49±0.05) pg/mL. (3) At culture hour 12-72, the proliferation activity of human fibroblasts in each hAMSCs-CS group was significantly higher than that in blank control group (with P values below 0.01), and the proliferation activity of human fibroblasts in 50% hAMSCs-CS group was the highest. (4) The width of scratch in two groups was nearly the same at PSH 0. The migration distance of cells in 50% hAMSCs-CS group was significantly longer than that in blank control group at PSH 12-72 (with P values below 0.01). (5) The apoptosis rate of human fibroblasts in blank control group was (16.2±2.4)%, which was significantly higher than that in 50% hAMSCs-CS group [(7.4±3.6)%, t=6.710, P<0.01]. hAMSCs-CS can promote proliferation and migration of human fibroblasts and inhibit the apoptosis of human fibroblasts.

SARS coronavirus papain-like protease induces Egr-1-dependent up-regulation of TGF-β1 via ROS/p38 MAPK/STAT3 pathway.

SARS coronavirus (SARS-CoV) papain-like protease (PLpro) has been identified in TGF-β1 up-regulation in human promonocytes (Proteomics 2012, 12: 3193-205). This study investigates the mechanisms of SARS-CoV PLpro-induced TGF-β1 promoter activation in human lung epithelial cells and mouse models. SARS-CoV PLpro dose- and time-dependently up-regulates TGF-β1 and vimentin in A549 cells. Dual luciferase reporter assays with TGF-β1 promoter plasmids indicated that TGF-β1 promoter region between −175 to −60, the Egr-1 binding site, was responsible for TGF-β1 promoter activation induced by SARS-CoV PLpro. Subcellular localization analysis of transcription factors showed PLpro triggering nuclear translocation of Egr-1, but not NF-κB and Sp-1. Meanwhile, Egr-1 silencing by siRNA significantly reduced PLpro-induced up-regulation of TGF-β1, TSP-1 and pro-fibrotic genes. Furthermore, the inhibitors for ROS (YCG063), p38 MAPK (SB203580), and STAT3 (Stattic) revealed ROS/p38 MAPK/STAT3 pathway involving in Egr-1 dependent activation of TGF-β1 promoter induced by PLpro. In a mouse model with a direct pulmonary injection, PLpro stimulated macrophage infiltration into lung, up-regulating Egr-1, TSP-1, TGF-β1 and vimentin expression in lung tissues. The results revealed that SARS-CoV PLpro significantly triggered Egr-1 dependent activation of TGF-β1 promoter via ROS/p38 MAPK/STAT3 pathway, correlating with up-regulation of pro-fibrotic responses in vitro and in vivo.

Reduced adhesive ligand density in engineered extracellular matrices induces an epithelial-mesenchymal-like transition

A synergistic effect of biochemical and mechanical cues emanating from the extracellular matrix (ECM) on inducing malignant transformation of epithelial cells has been observed recently. However, the effect of quantitative changes in biochemical stimuli on cell phenotype, without changes in ECM component and rigidity, remains unknown. To determine this effect, we grew Madin-Darby canine kidney epithelial cells (MDCK) on gold surfaces immobilized with varying densities of cyclic arginine-glycine-aspartate (cRGD) peptide and analyzed cell morphology, cell migration, cytoskeletal organization, and protein expression. Cells grown on a surface presenting a higher density of cRGD displayed an epithelial morphology and grew in clusters, while those grown on a diluted cRGD surface transformed into an elongated, fibroblast-like form with extensive scattering. Time-lapse imaging of cell clusters grown on the concentrated cRGD surface revealed collective migration with intact cell-cell contacts accompanied by the development of cortical actin. In contrast, cells migrated individually and formed stress fibers on the substrate with sparse cRGD. These data point towards transdifferentiation of epithelial cells to mesenchymal-like cells when plated on a diluted cRGD surface. Supporting this hypothesis, immunofluorescence microscopy and western blot analysis revealed increased membrane localization and total expression of N-cadherin and vimentin in cells undergoing mesenchymal-like transition. Taken together, these results suggest a possible role of decreased biochemical stimuli from the ECM in regulating epithelial phenotype switching. Statement of SignificanceEpithelial-mesenchymal transition (EMT) is a process where adherent epithelial cells convert into individual migratory mesenchymal phenotype. It plays an important role both in physiological and pathological processes. Recent studies demonstrate that the program is not only governed by soluble factors and gene expressions, but also modulated by biochemical and mechanical cues in ECMs. In this study, we developed chemically defined surfaces presenting controlled ECM ligand densities and studied their impact on the EMT progression. Morphological and biochemical analyses of epithelial cells cultured on the surfaces indicate the cells undergo an EMT-like transition on the diluted cRGD surface while retaining epithelial characteristics on the cRGD-rich substrate, suggesting an important role of the ECM ligand density in epithelial phenotype switching.