scholarly journals Predominant Distribution of the RNAi Machinery at Apical Adherens Junctions in Colonic Epithelia Is Disrupted in Cancer

2020 ◽  
Vol 21 (7) ◽  
pp. 2559 ◽  
Author(s):  
Joyce Nair-Menon ◽  
Amanda C. Daulagala ◽  
Dean M. Connor ◽  
Lauren Rutledge ◽  
Trevor Penix ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Epithelial Cells ◽  
Cancer Cell ◽  
Adherens Junctions ◽  
Mirna Biogenesis ◽  
Cell Contact ◽  
Rnai Machinery ◽  
The Core

The RNA interference (RNAi) machinery is an essential component of the cell, regulating miRNA biogenesis and function. RNAi complexes were thought to localize either in the nucleus, such as the microprocessor, or in the cytoplasm, such as the RNA-induced silencing complex (RISC). We recently revealed that the core microprocessor components DROSHA and DGCR8, as well as the main components of RISC, including Ago2, also associate with the apical adherens junctions of well-differentiated cultured epithelial cells. Here, we demonstrate that the localization of the core RNAi components is specific and predominant at apical areas of cell-cell contact of human normal colon epithelial tissues and normal primary colon epithelial cells. Importantly, the apical junctional localization of RNAi proteins is disrupted or lost in human colon tumors and in poorly differentiated colon cancer cell lines, correlating with the dysregulation of the adherens junction component PLEKHA7. We show that the restoration of PLEKHA7 expression at adherens junctions of aggressively tumorigenic colon cancer cells restores the junctional localization of RNAi components and suppresses cancer cell growth in vitro and in vivo. In summary, this work identifies the apical junctional localization of the RNAi machinery as a key feature of the differentiated colonic epithelium, with a putative tumor suppressing function.

scholarly journals NF-κB maintains the stemness of colon cancer cells by downregulating miR-195-5p/497–5p and upregulating MCM2

2020 ◽  
Vol 39 (1) ◽  
Author(s):  
Longgang Wang ◽  
Jinxiang Guo ◽  
Jin Zhou ◽  
Dongyang Wang ◽  
Xiuwen Kang ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Human Colon ◽  
Colon Cancer Cells ◽  
Tumor Models ◽  
Human Colon Cancer ◽  
Subcutaneous Tumor

Abstract Background Colon cancer represents one of the leading causes of gastrointestinal tumors in industrialized countries, and its incidence appears to be increasing at an alarming rate. Accumulating evidence has unveiled the contributory roles of cancer stem cells (CSCs) in tumorigenicity, recurrence, and metastases. The functions of NF-kappa B (NF-κB) activation on cancer cell survival, including colon cancer cells have encouraged us to study the role of NF-κB in the maintenance of CSCs in colon cancer. Methods Tumor samples and matched normal samples were obtained from 35 colon cancer cases. CSCs were isolated from human colon cancer cell lines, where the stemness of the cells was evaluated by cell viability, colony-forming, spheroid-forming, invasion, migration, and apoptosis assays. NF-κB activation was then performed in subcutaneous tumor models of CSCs by injecting lipopolysaccharides (LPS) i.p. Results We found that NF-κB activation could reduce the expression of miR-195-5p and miR-497-5p, where these two miRNAs were determined to be downregulated in colon cancer tissues, cultured colon CSCs, and LPS-injected subcutaneous tumor models. Elevation of miR-195-5p and miR-497-5p levels by their specific mimic could ablate the effects of NF-κB on the stemness of colon cancer cells in vivo and in vitro, suggesting that NF-κB could maintain the stemness of colon cancer cells by downregulating miR-195-5p/497–5p. MCM2 was validated as the target gene of miR-195-5p and miR-497-5p in cultured colon CSCs. Overexpression of MCM2 was shown to restore the stemness of colon cancer cells in the presence of miR-195-5p and miR-497-5p, suggesting that miR-195-5p and miR-497-5p could impair the stemness of colon cancer cells by targeting MCM2 in vivo and in vitro. Conclusions Our work demonstrates that the restoration of miR-195-5p and miR-497-5p may be a therapeutic strategy for colon cancer treatment in relation to NF-κB activation.

scholarly journals A critical role of CCR7 in invasiveness and metastasis of SW620 colon cancer cell in vitro and in vivo

2008 ◽  
Vol 7 (7) ◽  
pp. 1037-1043 ◽  
Author(s):  
Yu Shuyi ◽  
Duan Juping ◽  
Zhou Zhiqun ◽  
Pang Qiong ◽  
Ji Wuyang ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Cancer Cell ◽  
Critical Role ◽  
Colon Cancer Cell

Isolation and characterization of spontaneous spheroid aggregates within human colon carcinomas

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 14515-14515
Author(s):  
V. Dangles-Marie ◽  
P. Validire ◽  
S. Richon ◽  
L. Weiswald ◽  
M. Briffod ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Cancer Cells ◽  
Cell Lines ◽  
Cancer Cell ◽  
Human Colon ◽  
Cancer Cell Lines ◽  
Mesenchymal Transition ◽  
Isolation And Characterization

14515 Background: In vitro spheroid model using cancer cell lines is widely admitted to mimic in vivo micro tumors, including micrometastases. Floating spheroid cell cluster culture has been recently used for normal and cancer stem cell expansion. Spontaneously spheroids generated in vivo have been only studied in ovarian cancer ascites while organoid aggregates have been sometimes observed in the establishment of human colon cancer cell lines. In this study, we investigated whether spontaneous spheroid aggregates from colon cancer could be isolated and characterized. Methods: 127 colorectal primary tumor specimens have been collected and mechanically dissociated into small fragments, which were then shortly cultured on cell plastic flask. Production of spheroid- like structures, referred to as colospheres, was examined at Day 1 and colospheres were gathered for phenotypic characterization. Results: Colospheres were successfully generated from 67 surgical specimens (53%). The capacity to form colospheres was strictly restricted to tumor tissue: dissociated normal colon mucosa never generated colospheres and colospheres were formed exclusively by cancer cells. The ability to generate colospheres was demonstrated to be significantly related to tumor aggressiveness, according to nodal status and AJCC’s stages (Chi-2 test, p<0.05). Immunohistochemical studies showed that cells forming colospheres were frequently positive for Ki67, and displayed often a disturbed expression of the epithelial caretaker E-cadherin. Peripheral cells of colospheres were able to migrate into Matrigel in absence of any chemoattractant. Conclusions: Collectively, the morphology of these colospheres derived directly from tumoral tissues and made up exclusively of cancer cells, their potential capacity to acquire an epithelial-to-mesenchymal transition phenotype and their in vitro migration ability could be aligned with the collective migration properties of carcinomas. Consequently, these ex vivo spherical structures might form an in vitro cell system for micrometastasis studies, at the very time when mortality among colorectal cancer patients continues to be attributed to metastasis development. No significant financial relationships to disclose.

scholarly journals In vitro and in vivo evaluation of colon cancer targeted epichlorohydrin crosslinked Portulaca-alginate beads

2018 ◽  
Vol 9 (1) ◽  
pp. 190-199 ◽  
Author(s):  
Geet P. Asnani ◽  
Chandrakant R. Kokare
Keyword(s):  
Colon Cancer ◽  
Cell Line ◽  
Cancer Cell ◽  
Cancer Cell Line ◽  
Colon Cancer Cell Line ◽  
Colon Cancer Cell ◽  
In Vivo Studies ◽  
Ht 29

AbstractThe aim of this study was to formulate a novel dual crosslinked hydrogel bead using Portulaca mucilage for colon-targeted delivery of 5-fluorouracil (5-FU) and evaluate its safety, specificity and efficacy. The ionotropic gelation technique was employed to prepare the hydrogel beads of Portulaca mucilage. For this, the mucilage was initially crosslinked with alginate and calcium ions. Epichlorohydrin was employed as a crosslinker in the second crosslinking step. The formulation was subjected to in vitro and in vivo studies to evaluate morphology, size, cytotoxicity, and organ distribution. Human HT-29 colon cancer cell-line was used for in vitro assays and in vivo studies were performed in Wistar rats to assess the usefulness and effectiveness of the formulation for colon cancer therapy. Microsphere sizes ranged from 930 to 977μm and possessed a high level of drug encapsulation efficiency (ca. 78% w/w). Compared with 5-FU solution (Tmax = 1.2 h, mean resident time: MRT = 3.3h) the dual crosslinked Portulaca microspheres exhibited sustained drug release after oral administration to rats (Tmax = 16h, MRT = 14h). The relative bioavailability of 5-FU solution and the microspheres were 100 and 93.6% respectively. Tissue distribution studies indicated high concentration of 5-FU in colon. In-vitro anticancer assay demonstrated IC50 value of 11.50 μg/ml against HT-29 colon cancer cell line. The epichlorohydrin cross-linked Portulaca microspheres prepared in this study provided sustained release of 5-FU up to 16h in the colonic region and enhanced the antitumor activity of the neoplastic drug. The formulation is hence an ideal carrier system for colon-targeted drug delivery.

scholarly journals Cell-to-Cell Contact as an Efficient Mode of Epstein-Barr Virus Infection of Diverse Human Epithelial Cells

1998 ◽  
Vol 72 (5) ◽  
pp. 4371-4378 ◽  
Author(s):  
Shosuke Imai ◽  
Jun Nishikawa ◽  
Kenzo Takada
Keyword(s):  
Epithelial Cells ◽  
Cell Lines ◽  
Viral Gene Expression ◽  
Viral Gene ◽  
Cell Contact ◽  
Barr Virus ◽  
Epithelial Cell Lines ◽  
Epstein Barr

ABSTRACT We show clear evidence for direct infection of various human epithelial cells by Epstein-Barr virus (EBV) in vitro. The successful infection was achieved by using recombinant EBV (Akata strain) carrying a selective marker gene but without any other artificial operations, such as introduction of the known EBV receptor (CD21) gene or addition of polymeric immunoglobulin A against viral gp350 in culture. Of 21 human epithelial cell lines examined, 18 became infected by EBV, as ascertained by the detection of EBV-determined nuclear antigen (EBNA) 1 expression in the early period after virus exposure, and the following selection culture easily yielded a number of EBV-infected clones from 15 cell lines. None of the human fibroblasts and five nonhuman-derived cell lines examined was susceptible to the infection. By comparison, cocultivation with virus producers showed ≈800-fold-higher efficiency of infection than cell-free infection did, suggesting the significance of direct cell-to-cell contact as a mode of virus spread in vivo. Most of the epithelial cell lines infectable with EBV were negative for CD21 expression at the protein and mRNA levels. The majority of EBV-infected clones established from each cell line invariably expressed EBNA1, EBV-encoded small RNAs, rightward transcripts from theBamHI-A region of the virus genome, and latent membrane protein (LMP) 2A, but not the other EBNAs or LMP1. This restricted form of latent viral gene expression, which is a central issue for understanding epithelial oncogenesis by EBV, resembled that seen in EBV-associated gastric carcinoma and LMP1-negative nasopharyngeal carcinoma. The results indicate that direct infection of epithelial cells by EBV may occur naturally in vivo, and this could be mediated by an unidentified, epithelium-specific binding receptor for EBV. The EBV convertants are viewed, at least in terms of viral gene expression, as in vitro analogs of EBV-associated epithelial tumor cells, thus facilitating analysis of an oncogenic role(s) for EBV in epithelial cells.

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