scholarly journals Tubulin Tyrosine Ligase Like 4 (TTLL4) overexpression in breast cancer cells is associated with brain metastasis and alters exosome biogenesis

Author(s):  
Julia Arnold ◽  
Juliana Schattschneider ◽  
Christine Blechner ◽  
Christoph Krisp ◽  
Hartmut Schlüter ◽  
...  

Abstract Background The survival rate is poor in breast cancer patients with brain metastases. Thus, new concepts for therapeutic approaches are required. During metastasis, the cytoskeleton of cancer cells is highly dynamic and therefore cytoskeleton-associated proteins are interesting targets for tumour therapy. Methods Screening for genes showing a significant correlation with brain metastasis formation was performed based on microarray data from breast cancer patients with long-term follow up information. Validation of the most interesting target was performed by MTT-, Scratch- and Transwell-assay. In addition, intracellular trafficking was analyzed by live-cell imaging for secretory vesicles, early endosomes and multiple vesicular bodies (MVB) generating extracellular vesicles (EVs). EVs were characterized by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), Western blotting, mass spectrometry, and ingenuity pathway analysis (IPA). Effect of EVs on the blood-brain-barrier (BBB) was examined by incubating endothelial cells of the BBB (hCMEC/D3) with EVs, and permeability as well as adhesion of breast cancer cells were analyzed. Clinical data of a breast cancer cohort was evaluated by χ2-tests, Kaplan-Meier-Analysis, and log-rank tests while for experimental data Student’s T-test was performed. Results Among those genes exhibiting a significant association with cerebral metastasis development, the only gene coding for a cytoskeleton-associated protein was Tubulin Tyrosine Ligase Like 4 (TTLL4). Overexpression of TTLL4 (TTLL4plus) in MDA-MB231 and MDA-MB468 breast cancer cells (TTLL4plus cells) significantly increased polyglutamylation of β-tubulin. Moreover, trafficking of secretory vesicles and MVBs was increased in TTLL4plus cells. EVs derived from TTLL4plus cells promote adhesion of MDA-MB231 and MDA-MB468 cells to hCMEC/D3 cells and increase permeability of hCMEC/D3 cell layer. Conclusions These data suggest that TTLL4-mediated microtubule polyglutamylation alters exosome homeostasis by regulating trafficking of MVBs. The TTLL4plus-derived EVs may provide a pre-metastatic niche for breast cancer cells by manipulating endothelial cells of the BBB.

2021 ◽  
pp. 1-10
Author(s):  
Yu Wang ◽  
Han Zhao ◽  
Ping Zhao ◽  
Xingang Wang

BACKGROUND: Pyruvate kinase M2 (PKM2) was overexpressed in many cancers, and high PKM2 expression was related with poor prognosis and chemoresistance. OBJECTIVE: We investigated the expression of PKM2 in breast cancer and analyzed the relation of PKM2 expression with chemotherapy resistance to the neoadjuvant chemotherapy (NAC). We also investigated whether PKM2 could reverse chemoresistance in breast cancer cells in vitro and in vivo. METHODS: Immunohistochemistry (IHC) was performed in 130 surgical resected breast cancer tissues. 78 core needle biopsies were collected from breast cancer patients before neoadjuvant chemotherapy. The relation of PKM2 expression and multi-drug resistance to NAC was compared. The effect of PKM2 silencing or overexpression on Doxorubicin (DOX) sensitivity in the MCF-7 cells in vitro and in vivo was compared. RESULTS: PKM2 was intensively expressed in breast cancer tissues compared to adjacent normal tissues. In addition, high expression of PKM2 was associated with poor prognosis in breast cancer patients. The NAC patients with high PKM2 expression had short survival. PKM2 was an independent prognostic predictor for surgical resected breast cancer and NAC patients. High PKM2 expression was correlated with neoadjuvant treatment resistance. High PKM2 expression significantly distinguished chemoresistant patients from chemosensitive patients. In vitro and in vivo knockdown of PKM2 expression decreases the resistance to DOX in breast cancer cells in vitro and tumors in vivo. CONCLUSION: PKM2 expression was associated with chemoresistance of breast cancers, and could be used to predict the chemosensitivity. Furthermore, targeting PKM2 could reverse chemoresistance, which provides an effective treatment methods for patients with breast cancer.


2012 ◽  
Vol 11 (11) ◽  
pp. 1457-1467 ◽  
Author(s):  
Olesya Chornoguz ◽  
Alexei Gapeev ◽  
Michael C. O'Neill ◽  
Suzanne Ostrand-Rosenberg

The major histocompatibility complex (MHC) class II-associated Invariant chain (Ii) is present in professional antigen presenting cells where it regulates peptide loading onto MHC class II molecules and the peptidome presented to CD4+ T lymphocytes. Because Ii prevents peptide loading in neutral subcellular compartments, we reasoned that Ii− cells may present peptides not presented by Ii+ cells. Based on the hypothesis that patients are tolerant to MHC II-restricted tumor peptides presented by Ii+ cells, but will not be tolerant to novel peptides presented by Ii− cells, we generated MHC II vaccines to activate cancer patients' T cells. The vaccines are Ii− tumor cells expressing syngeneic HLA-DR and the costimulatory molecule CD80. We used liquid chromatography coupled with mass spectrometry to sequence MHC II-restricted peptides from Ii+ and Ii− MCF10 human breast cancer cells transfected with HLA-DR7 or the MHC Class II transactivator CIITA to determine if Ii− cells present novel peptides. Ii expression was induced in the HLA-DR7 transfectants by transfection of Ii, and inhibited in the CIITA transfectants by RNA interference. Peptides were analyzed and binding affinity predicted by artificial neural net analysis. HLA-DR7-restricted peptides from Ii− and Ii+ cells do not differ in size or in subcellular location of their source proteins; however, a subset of HLA-DR7-restricted peptides of Ii− cells are not presented by Ii+ cells, and are derived from source proteins not used by Ii+ cells. Peptides from Ii− cells with the highest predicted HLA-DR7 binding affinity were synthesized, and activated tumor-specific HLA-DR7+ human T cells from healthy donors and breast cancer patients, demonstrating that the MS-identified peptides are bonafide tumor antigens. These results demonstrate that Ii regulates the repertoire of tumor peptides presented by MHC class II+ breast cancer cells and identify novel immunogenic MHC II-restricted peptides that are potential therapeutic reagents for cancer patients.


2021 ◽  
Author(s):  
Duo You ◽  
Danfeng Du ◽  
Xueke Zhao ◽  
Xinmin Li ◽  
Minfeng Ying ◽  
...  

Abstract Background: α-ketoglutarate (α-KG) is the substrate to hydoxylate collagen and hypoxia-inducible factor-1α (HIF-1α), which are important for cancer metastasis. Previous studies showed that upregulation of collagen prolyl 4-hydroxylase in breast cancer cells stabilizes HIF-1α via depleting α-KG in breast cancer cells. We propose that mitochondrial malate enzyme 2 (ME2) may also affect HIF-1α via modulating α-KG level in breast cancer cells. Methods: ME2 protein expression was evaluated by immunohistochemistry on 100 breast cancer patients and correlated with clinicopathological indicators. The effect of ME2 knockout on cancer metastasis was evaluated by an orthotopic breast cancer model. The effect of ME2 knockout or knockdown on the levels of α-KG and HIF-1α protein in breast cancer cell lines (4T1 and MDA-MB-231) was determined in vitro and in vivo.Results: The high expression of ME2 was observed in the human breast cancerous tissues compared to the matched precancerous tissues (P=0.000). The breast cancer patients with a high expression of ME2 had an inferior survival than the patients with low expression of ME2 (P=0.019). ME2 high expression in breast cancer tissues was also related with lymph node metastasis (P=0.016), pathological staging (P=0.033) and vascular cancer embolus (P=0.014). In a 4T1 orthotopic breast cancer model, ME2 knockout significantly inhibited lung metastasis. In the tumors formed by ME2 knockout 4T1 cells, α-KG level significantly increased, collagen hydroxylation level did not change significantly, but HIF-1α protein level significantly decreased, in comparison to control. In cell culture, ME2 knockout or knockdown cells demonstrated a significantly higher α-KG level but significantly lower HIF-1α protein level than control cells under hypoxia. Exogenous malate and α-KG exerted similar effect on HIF-1α in breast cancer cells to ME2 knockout or knockdown. Treatment with malate significantly decreased 4T1 breast cancer lung metastasis. ME2 expression was associated with HIF-1α level in human breast cancer samples (P=0.027).Conclusion: We provide evidence that upregulation of ME2 is associated with a poor prognosis of breast cancer patients and propose a mechanistic understanding of a link between ME2 and breast cancer metastasis.


2005 ◽  
Vol 23 (16_suppl) ◽  
pp. 9638-9638
Author(s):  
F. Janku ◽  
G. Korinkova ◽  
J. Srovnal ◽  
Z. Kleibl ◽  
J. Novotny ◽  
...  

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e12575-e12575
Author(s):  
Ji Ma ◽  
Lingqi Sun ◽  
Ying Liu ◽  
Hui Ren ◽  
Yali Shen ◽  
...  

e12575 Background: The aim was to evaluate the changes of 16S rDNA sequencing and LC-MS metabolomics in breast cancer and explore the growth inhibition of breast cancer cells by Faecalibacterium prausnitzii. Methods: We performed the 16S rDNA sequencing of gut bacteria and the LC-MS metabolomics analysis of blood samples in 25 breast cancer patients and 25 benign breast disease controls. Correlation analysis of significant flora and metabolites were processed, including correlation coefficient calculation, matrix heat map analysis, cluster analysis, correlation network analysis, and scatter plot analysis. We screened for intestinal flora that may participate in breast cancer development and try to test and verify. CCK-8, apoptosis and transwell assays were explored to detect the growth inhibition of breast cancer cells by Faecalibacterium prausnitzii. Western blot was used to analyze the changes of IL-6/STAT3 pathway by Faecalibacterium prausnitzii. Results: Total 49 significantly different flora and 26 different metabolites were screened between two groups, and the correlation was calculated. Relative abudance of Firmicutes and Bacteroidetes were decreased, while relative abundance of verrucomicrobla, proteobacteria and actinobacteria was increased in breast cancer group. Differentially expressed metabolites were mainly enriched in pathways such as linoleic acid metabolism, retrograde endocannabinoid signaling, biosynthesis of unsaturated fatty acids, choline metabolism in cancer and arachidonic acid metabolism. Lipid upregulation was found in breast cancer patients, especially phosphorocholine. The abundance of Faecalibacterium was reduced in breast cancer patients, which was negatively correlated with various phosphorylcholines. Moreover, Faecalibacterium prausnitzii, the most well-known species in Faecalibacterium genus, could inhibit the secretion of IL-6 and the phosphorylation of JAK2/STAT3 in breast cancer cells. Faecalibacterium prausnitzii also suppressed the proliferation and invasion and promoted the apoptosis of breast cancer cells, while these effects disappeared after adding recombinant human IL-6. Conclusions: Flora-metabolites combined with the flora-bacteria (such as Faecalibacterium combined with phosphorocholine) might a new detection method for breast cancer. Faecalibacterium may be helpful for prevention of breast cancer. Faecalibacterium prausnitzii suppresses the growth of breast cancer cells through inhibition of IL-6/STAT3 pathway.


2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 3543-3543 ◽  
Author(s):  
Jason Brown ◽  
Palak Shah ◽  
Josh Vo ◽  
Lanbo Xiao ◽  
Yashar Niknafs ◽  
...  

3543 Background: Non-invasive testing in plasma using RNA biomarkers has been limited by exoribonuclease-mediated degradation of RNA. Circular RNA (circRNA) are covalently closed RNA structures that resist this degradation due to their circular structure. Therefore circRNA are more stable than their linear counterparts. CircRNA are formed by alternative backsplicing of the 3’ end of a downstream exon to the 5’ end of an upstream exon. Here, we propose a novel method for non-invasive identification of circRNA and demonstrate circularized forms of several lineage and cancer specific targets for estrogen receptor-positive breast cancer. Methods: Capture RNA sequencing on cancer tissue was previously performed to determine the relative expression of potential circRNA isoforms in breast cancer patients. These isoforms as well as those predicted by intron length were screened using a quantitative PCR-based assay on ER-positive breast cancer cells. RNA extracted from breast cancer cells are exposed to ribonuclease R to demonstrate stability of circRNA. CircRNA derived from targets with known universal expression are used as positive controls as well as for analysis on plasma. Results: We identify the circRNA isoforms with highest expression for five genes, including ESR1, that are differentially expressed in ER-positive breast cancer compared to other cancers and normal breast tissue. We determine that the circRNA corresponding to all five targets is specifically expressed in breast cancer cell lines with at least 1000-fold higher expression than in non-ER positive breast cancer cell lines. We demonstrate that the highest expressing circRNA isoforms are resistant to degradation by ribonuclease R, whereas corresponding linear mRNA is susceptible. We also demonstrate the presence and stability of positive control circRNA in plasma from patients without cancer. Conclusions: CircRNA are promising biomarkers for early non-invasive detection of cancer due to their stability in plasma. This assay reliably detects ER-positive breast cancer specific circRNA, and exoribonuclease resistance has been validated. Application of this diagnostic assay to plasma from breast cancer patients is underway.


Cancers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1255 ◽  
Author(s):  
Patrik Kovács ◽  
Tamás Csonka ◽  
Tünde Kovács ◽  
Zsanett Sári ◽  
Gyula Ujlaki ◽  
...  

In breast cancer patients, the diversity of the microbiome decreases, coinciding with decreased production of cytostatic bacterial metabolites like lithocholic acid (LCA). We hypothesized that LCA can modulate oxidative stress to exert cytostatic effects in breast cancer cells. Treatment of breast cancer cells with LCA decreased nuclear factor-2 (NRF2) expression and increased Kelch-like ECH associating protein 1 (KEAP1) expression via activation of Takeda G-protein coupled receptor (TGR5) and constitutive androstane receptor (CAR). Altered NRF2 and KEAP1 expression subsequently led to decreased expression of glutathione peroxidase 3 (GPX3), an antioxidant enzyme, and increased expression of inducible nitric oxide synthase (iNOS). The imbalance between the pro- and antioxidant enzymes increased cytostatic effects via increased levels of lipid and protein oxidation. These effects were reversed by the pharmacological induction of NRF2 with RA839, tBHQ, or by thiol antioxidants. The expression of key components of the LCA-elicited cytostatic pathway (iNOS and 4HNE) gradually decreased as the breast cancer stage advanced. The level of lipid peroxidation in tumors negatively correlated with the mitotic index. The overexpression of iNOS, nNOS, CAR, KEAP1, NOX4, and TGR5 or the downregulation of NRF2 correlated with better survival in breast cancer patients, except for triple negative cases. Taken together, LCA, a metabolite of the gut microbiome, elicits oxidative stress that slows down the proliferation of breast cancer cells. The LCA–oxidative stress protective pathway is lost as breast cancer progresses, and the loss correlates with poor prognosis.


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