scholarly journals Siglec-15 recognition of sialoglycans on tumor cell lines can occur independently of sialyl Tn antigen expression

Glycobiology ◽  
2020 ◽  
Author(s):  
Gavuthami Murugesan ◽  
Viviana G Correia ◽  
Angelina S Palma ◽  
Wengang Chai ◽  
Chunxia Li ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Cell Lines ◽  
Antigen Expression ◽  
Mapk Signaling ◽  
Breast Cancer Cell Lines ◽  
Cross Linking ◽  
Monocytic Cell ◽  
Immunosuppressive Microenvironment ◽  
Sialyl Tn Antigen ◽  
Sialyl Tn

Abstract Siglec-15 is a conserved sialic acid-binding Ig-like lectin expressed on osteoclast progenitors, which plays an important role in osteoclast development and function. It is also expressed by tumor-associated macrophages and by some tumors, where it is thought to contribute to the immunosuppressive microenvironment. It was shown previously that engagement of macrophage-expressed Siglec-15 with tumor cells expressing its ligand, sialyl Tn (sTn), triggered production of TGF-β. In the present study, we have further investigated the interaction between Siglec-15 and sTn on tumor cells and its functional consequences. Based on binding assays with lung and breast cancer cell lines and glycan-modified cells, we failed to see evidence for recognition of sTn by Siglec-15. However, using a microarray of diverse, structurally defined glycans, we show that Siglec-15 binds with higher avidity to sialylated glycans other than sTn or related antigen sequences. In addition, we were unable to demonstrate enhanced TGF-β secretion following co-culture of Siglec-15-expressing monocytic cell lines with tumor cells expressing sTn or following Siglec-15 cross-linking with monoclonal antibodies. However, we did observe activation of the SYK/MAPK signaling pathway following antibody cross-linking of Siglec-15 that may modulate the functional activity of macrophages.

scholarly journals Productive Infection of Human Breast Cancer Cell Lines with Human Cytomegalovirus (HCMV)

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 641
Author(s):  
Kaitlin M. Branch ◽  
Erica C. Garcia ◽  
Yin Maggie Chen ◽  
Matthew McGregor ◽  
Mikayla Min ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tumor Cells ◽  
Cell Lines ◽  
Cancer Cell ◽  
Breast Cancer Cell ◽  
Breast Tumor ◽  
Cancer Cell Lines ◽  
Breast Cancer Cell Lines ◽  
Human Breast ◽  
Breast Tumor Cells

Breast cancer is the leading cause of cancer deaths among women worldwide. There are many known risk factors for breast cancer, but the role of infectious disease remains unclear. Human cytomegalovirus (HCMV) is a widespread herpesvirus that usually causes little disease. Because HCMV has been detected in breast tumor biopsy samples and is frequently transmitted via human breast milk, we investigated HCMV replication in breast tumor cells. Four human breast cancer cell lines with different expression profiles for the key diagnostic markers of the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2), were infected with a bacterial artificial chromosome-derived HCMV clinical strain TB40/E tagged with green fluorescent protein (GFP). Fluorescence microscopy confirmed that all four breast cancer cell lines supported virus entry. RNA was isolated from infected cells and the expression of immediate early (UL123), early (UL54), and late (UL111A) genes was confirmed using PCR. Viral proteins were detected by immunoblotting, and viral progeny were produced during the infection of breast tumor cells, as evidenced by subsequent infection of fibroblasts with culture supernatants. These results demonstrate that breast tumor cells support productive HCMV infection and could indicate that HCMV replication may play a role in breast cancer progression.

A truncated intracellular HER2/neu receptor produced by alternative RNA processing affects growth of human carcinoma cells

1993 ◽  
Vol 13 (4) ◽  
pp. 2247-2257
Author(s):  
G K Scott ◽  
R Robles ◽  
J W Park ◽  
P A Montgomery ◽  
J Daniel ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tumor Cells ◽  
Cell Lines ◽  
Rna Processing ◽  
Human Tumor ◽  
Full Length ◽  
Splice Donor Site ◽  
Breast Cancer Cell Lines ◽  
Her2 Receptor ◽  
Human Carcinoma

Cloned sequences encoding a truncated form of the HER2 receptor were obtained from cDNA libraries derived from two HER2-overexpressing human breast cancer cell lines, BT-474 and SK-BR-3. The 5' 2.1 kb of the encoded transcript is identical to that of full-length 4.6-kb HER2 transcript and would be expected to produce a secreted form of HER2 receptor containing only the extracellular ligand binding domain (ECD). The 3' end of the truncated transcript diverges 61 nucleotides before the receptor's transmembrane region, reads through a consensus splice donor site containing an in-frame stop codon, and contains a poly(A) addition site, suggesting that the truncated transcript arises by alternative RNA processing. S1 nuclease protection assays show a 40-fold variation in the abundance of the truncated 2.3-kb transcript relative to full-length 4.6-kb transcript in a panel of eight HER2-expressing tumor cell lines of gastric, ovarian, and breast cancer origin. Expression of this truncated transcript in COS-1 cells produces both secreted and intracellular forms of HER2 ECD; however, immunofluorescent labeling of HER2 ECD protein in MKN7 tumor cells that natively overexpress the 2.3-kb transcript suggests that transcriptionally generated HER2 ECD is concentrated within the perinuclear cytoplasm. Metabolic labeling and endoglycosidase studies suggest that this HER2 ECD (100 kDa) undergoes differential trafficking between the endoplasmic reticulum and Golgi compartments compared with full-length (185-kDa) HER2 receptor. Transfection studies indicate that excess production of HER2 ECD in human tumor cells overexpressing full-length HER2 receptor can result in resistance to the growth-inhibiting effects of anti-HER2 monoclonal antibodies such as muMAb4D5. These findings demonstrate alternative processing of the HER2 transcript and implicate a potentially important growth regulatory role for intracellularly sequestered HER2 ECD in HER2-amplified human tumors.

scholarly journals Sialic acid-binding lectin-modified fructose-coated nanoparticles: a promising targeted therapeutic synthetic for breast cancers

2020 ◽  
Author(s):  
Lin He ◽  
Biyuan Zhang ◽  
Yuhua Song ◽  
Haiji Wang
Keyword(s):  
Breast Cancer ◽  
Cell Cycle ◽  
Cancer Cells ◽  
Tumor Cells ◽  
Cell Lines ◽  
Breast Cancer Cells ◽  
Breast Cancer Cell Lines ◽  
Multiple Drug ◽  
Her2 Overexpression ◽  
Coated Nanoparticles

Abstract Background: Sialic acid-binding lectin (cSBL) specifically kills tumor cells rather than healthy cells. Glycopolymer-coated nanoparticles are selectively ingested by tumor cells because they can interact with the enriched carbohydrate receptors located on the surface of tumor cells. In this context, we synthesized cSBL-modified fructose-coated nanoparticles (LMFN) and cSBL-modified glucose-coated nanoparticles (LMGN) to investigate their anticancer activity in various molecular subtypes of breast cancer cell lines. Methods: The syntheses of fructose-coated nanoparticles and glucose-coated nanoparticles were based on the chemicals of 1,2:4,5-di- O -isopropylidene- β -d-fructopyranose and 1,2:4,5-di- O -isopropylidene- β -d-glucopyranose, respectively. The carbodiimide-based method was employed to synthesize LMFN and LMGN. The antitumor mechanism was explored by cell cycle analysis with flowcytometry and the antitumor activity was assessed by cytotoxicity assay and multiple drug effects analysis. Results: The cytotoxicity assay showed that LMFN had robust antitumor activity against all breast cancer phenotype cell lines whereas LMGN was rarely efficacious to against human epidermal growth factor receptor 2-positive/overexpression (HER2+/overexpression) breast cancer cells. The intrinsic reason for these findings was that the overexpression of fructose transporter, GLUT5, was observed in all breast cancer subtype cell lines but only a paucity of glucose transporter, GLUT1, was expressed in HER2+/overexpression breast cancer cell lines that dampened the uptake of LMGN to these cells. The cell cycle analysis indicated that the anticancer activity of LMFN was achieved by arresting cell cycle in S phase. The multiple drug effects analysis suggested the synergistic effect in the combinations of LMFN and tamoxifen to kill estrogen receptor+ breast cancer cells and LMFN and trastuzumab to kill HER2+/overexpressed breast cancer cells. Conclusion: Our work pinpoints that LMFN may be a new-onset selection for molecularly targeted therapy of breast cancers and paves the way for establishing its clinical application in the future.

scholarly journals Periostin gene expression in neu-positive breast cancer cells is regulated by a FGFR signaling cross talk with TGFβ/PI3K/AKT pathways

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Cédrik Labrèche ◽  
David P. Cook ◽  
John Abou-Hamad ◽  
Julia Pascoal ◽  
Benjamin R. Pryce ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Cancer Cells ◽  
Tumor Cells ◽  
Cell Lines ◽  
Breast Cancer Cells ◽  
Breast Cancer Cell Lines ◽  
Matricellular Protein ◽  
Stromal Compartment ◽  
Primary Tumors

Abstract Background Breast cancer is a highly heterogeneous disease with multiple drivers and complex regulatory networks. Periostin (Postn) is a matricellular protein involved in a plethora of cancer types and other diseases. Postn has been shown to be involved in various processes of tumor development, such as angiogenesis, invasion, cell survival and metastasis. The expression of Postn in breast cancer cells has been correlated with a more aggressive phenotype. Despite extensive research, it remains unclear how epithelial cancer cells regulate Postn expression. Methods Using murine tumor models and human TMAs, we have assessed the proportion of tumor samples that have acquired Postn expression in tumor cells. Using biochemical approaches and tumor cell lines derived from Neu+ murine primary tumors, we have identified major regulators of Postn gene expression in breast cancer cell lines. Results Here, we show that, while the stromal compartment typically always expresses Postn, about 50% of breast tumors acquire Postn expression in the epithelial tumor cells. Furthermore, using an in vitro model, we show a cross-regulation between FGFR, TGFβ and PI3K/AKT pathways to regulate Postn expression. In HER2-positive murine breast cancer cells, we found that basic FGF can repress Postn expression through a PKC-dependent pathway, while TGFβ can induce Postn expression in a SMAD-independent manner. Postn induction following the removal of the FGF-suppressive signal is dependent on PI3K/AKT signaling. Conclusion Overall, these results reveal a novel regulatory mechanism and shed light on how breast tumor cells acquire Postn expression. This complex regulation is likely to be cell type and cancer specific as well as have important therapeutic implications.

Involvement of ppGalNAc-T6, a new colon cancer marker, in the molecular basis of simple mucin-type O-glycosylated antigen expression

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e15060-e15060
Author(s):  
L. Ubillos ◽  
N. Berois ◽  
D. Mazal ◽  
V. Braña ◽  
C. Yacoel ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Cell Lines ◽  
Molecular Basis ◽  
Antigen Expression ◽  
Initial Step ◽  
Enzyme Expression ◽  
Normal Colon ◽  
Abnormal Expression ◽  
Colon Cell ◽  
Sialyl Tn

e15060 Background: Abnormal O-glycosylation is one of the most common changes during colon carcinogenesis, leading to the expression of short truncated O-glycan antigens (such as Tn, sialyl-Tn, Tk, and core 6). These structures which are related with the malignant behavior are actively investigated as immunotherapeutic targets. The ppGalNAc-T family enzymes regulate the initial step of mucin O-glycosylation and could be responsible for the altered glycosylation observed in cancer. The objective of this work was to describe the abnormal expression of ppGalNAc-Ts in colon cancer comparing its relationship with incomplete O- glycosylated antigens. Methods: We studied the gene expression of ppGalNAc-Ts in colon cell lines by RT-PCR assays. Using immunohistochemistry we determined ppGalNAc-T6, Tn, sialyl-Tn, Tk, and core 6 expression in 64 colon cancer samples and in 10 normal colon tissues. Results: We found that ppGalNAc-T6 (an enzyme usually restricted to normal placenta, trachea, brain, and pancreas) is expressed by colon cancer cell lines. Using immunohistochemistry we detected ppGalNAc-T6 in 70.3% of cancer samples with no staining in normal colon tissues. Staining pattern was predominantly cytoplasmatic. Staining of Tn, STn, core 6 and Tk antigens was observed in 87,5%, 79,6%, 76,5% and 68.7% of tumors, respectively. We observed a statistically significant relationship between the enzyme expression and Tn antigen (p=0.009) and core 6 (p=0.001). No relationship was observed between the enzyme expression and sialyl-Tn (p = 0.406) and Tk (p= 0.18) antigens. Conclusions: ppGalNac-T6 is a new tumor marker for colon cancer and its expression is related with the accumulation of two O-glycosylated antigens such as Tn and core 6. This is the first evidence in human tissues suggesting that the abnormal expression of a ppGalNac transferase could be in the molecular basis of aberrant O-glycosylated antigens accumulation in cancer. No significant financial relationships to disclose.

scholarly journals Terminal α1,4-linked N-acetylglucosamine in Helicobacter pylori-associated Intestinal Metaplasia of the Human Stomach and Gastric Carcinoma Cell Lines

2006 ◽  
Vol 54 (5) ◽  
pp. 585-591 ◽  
Author(s):  
Bibiana Ferreira ◽  
Nuno T. Marcos ◽  
Leonor David ◽  
Jun Nakayama ◽  
Celso A. Reis
Keyword(s):  
Helicobacter Pylori ◽  
Gastric Carcinoma ◽  
Cell Lines ◽  
Carcinoma Cell ◽  
Tn Antigen ◽  
Gastric Carcinoma Cell ◽  
Carcinoma Cell Lines ◽  
Gastric Carcinoma Cell Lines ◽  
Sialyl Tn Antigen ◽  
Sialyl Tn

Helicobacter pylori (Hp) infection is associated with the development of gastric lesions including gastritis, intestinal metaplasia (IM), and gastric carcinoma. In humans, Hp is found almost exclusively in the foveolar epithelium of the gastric mucosa and rarely colonizes the deeper portions where mucous cells of the glands produce mucins with terminal α1, 4-GlcNAc O-glycans. This structure exerts antimicrobial activity against Hp. The development of IM in the stomach is characterized by Hp clearance from the metaplastic glands and by major alterations in the expression of mucins and mucin-carbohydrates. The present work evaluated whether terminal α1,4-GlcNAc and sialyl-Tn antigen are implicated in the process of Hp clearance from metaplastic glands by analyzing the expression of these antigens in different types of IM—complete ( n=12) and incomplete ( n=8)—and in gastric cell lines. Terminal α1,4-GlcNAc was not detected in IM except in a single foci of one case, indicating that this structure is not implicated in the clearance of Hp from IM, in contrast to what is observed in normal gastric mucosa. None of the gastric carcinoma cell lines studied showed terminal α1,4-GlcNAc, suggesting that they do not display a gastric gland mucous cell phenotype and therefore are useful models for in vitro Hp studies. Finally, sialyl-Tn antigen colocalizes with MUC2 mucin and is present in all cases of complete and incomplete IM, suggesting that either or both can be implicated in Hp clearance from IM. (J Histochem Cytochem 54:585-591, 2006)

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