scholarly journals SUSD2 Proteolytic Cleavage Requires the GDPH Sequence and Inter-Fragment Disulfide Bonds for Surface Presentation of Galectin-1 on Breast Cancer Cells

2019 ◽  
Vol 20 (15) ◽  
pp. 3814 ◽  
Author(s):  
Mitch E. Patrick ◽  
Kristi A. Egland
Keyword(s):  
Breast Cancer ◽  
T Cell ◽  
Cell Surface ◽  
Cancer Cells ◽  
Serine Protease ◽  
Breast Cancer Cells ◽  
Cancer Metastasis ◽  
Transmembrane Protein ◽  
Dependent Manner ◽  
Tumor Immune Evasion

Galectin-1 (Gal-1) is a 14 kDa protein that has been well characterized for promoting cancer metastasis and tumor immune evasion. By localizing to the cancer cell surface, Gal-1 induces T cell apoptosis through binding T cell surface receptors. The transmembrane protein, Sushi Domain Containing 2 (SUSD2), has been previously shown to be required for Gal-1 surface presentation in breast cancer cells. Western immunoblot analysis revealed that SUSD2 is cleaved into two fragments. However, the significance of this cleavage for Gal-1 surface localization has not been investigated. To define the location of cleavage, a mutagenesis analysis of SUSD2 was performed. Our studies demonstrated that SUSD2 is cleaved at its glycine-aspartic acid-proline-histidine (GDPH) amino acid sequence. Generation of a noncleavable SUSD2 mutant (GDPH∆-SUSD2) showed that SUSD2 cleavage was required for SUSD2 and Gal-1 plasma membrane localization. Noncleavable cysteine mutants were also unable to present Gal-1 at the cell surface, further demonstrating that SUSD2 cleavage is required for Gal-1 surface presentation. Treatment with the serine protease inhibitor, Pefabloc SC, inhibited SUSD2 cleavage in a dose dependent manner, suggesting that SUSD2 is cleaved by a serine protease. Therefore, identification and inhibition of this protease may provide a new therapeutic tool for inhibiting SUSD2 and Gal-1′s combined tumorigenic function in breast cancer.

scholarly journals GRP78 regulates CD44v membrane homeostasis and cell spreading in tamoxifen-resistant breast cancer

2019 ◽  
Vol 2 (4) ◽  
pp. e201900377 ◽  
Author(s):  
Chun-Chih Tseng ◽  
Ramunas Stanciauskas ◽  
Pu Zhang ◽  
Dennis Woo ◽  
Kaijin Wu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Surface ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Cancer Metastasis ◽  
Cell Spreading ◽  
Single Particle Tracking ◽  
Cell Surface Expression ◽  
Juxtamembrane Region ◽  
Tamoxifen Resistant

GRP78 conducts protein folding and quality control in the ER and shows elevated expression and cell surface translocation in advanced tumors. However, the underlying mechanisms enabling GRP78 to exert novel signaling functions at cell surface are just emerging. CD44 is a transmembrane protein and an important regulator of cancer metastasis, and isoform switch of CD44 through incorporating additional variable exons to the extracellular juxtamembrane region is frequently observed during cancer progression. Using super-resolution dual-color single-particle tracking, we report that GRP78 interacts with CD44v in plasma membrane nanodomains of breast cancer cells. We further show that targeting cell surface GRP78 by the antibodies can effectively reduce cell surface expression of CD44v and cell spreading of tamoxifen-resistant breast cancer cells. Our results uncover new functions of GRP78 as an interacting partner of CD44v and as a regulator of CD44v membrane homeostasis and cell spreading. This study also provides new insights into anti-CD44 therapy in tamoxifen-resistant breast cancer.

scholarly journals Transmembrane protein 97 exhibits oncogenic properties via enhancing LRP6-mediated Wnt signaling in breast cancer

2021 ◽  
Vol 12 (10) ◽  
Author(s):  
Huifang Zhu ◽  
Zijie Su ◽  
Jiong Ning ◽  
Liang Zhou ◽  
Lifeng Tan ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Wnt Signaling ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Target Genes ◽  
Transmembrane Protein ◽  
Xenograft Model ◽  
Dependent Manner ◽  
Interacting Protein ◽  
Targeted Inhibition

AbstractUpregulation of transmembrane protein 97 (TMEM97) has been associated with progression and poor outcome in multiple human cancers, including breast cancer. Recent studies suggest that TMEM97 may be involved in the activation of the Wnt/β-catenin pathway. However, the molecular mechanism of TMEM97 action on Wnt/β-catenin signaling is completely unclear. In the current study, TMEM97 was identified as an LRP6-interacting protein. TMEM97 could interact with LRP6 intracellular domain and enhance LRP6-mediated Wnt signaling in a CK1δ/ε-dependent manner. The binding of TMEM97 to LRP6 facilitated the recruitment of CK1δ/ε to LRP6 complex, resulting in LRP6 phosphorylation at Ser 1490 and the stabilization of β-catenin. In breast cancer cells, knockout of TMEM97 attenuated the Wnt/β-catenin signaling cascade via regulating LRP6 phosphorylation, leading to a decrease in the expression of Wnt target genes AXIN2, LEF1, and survivin. TMEM97 deficiency also suppressed cell viability, proliferation, colony formation, migration, invasion, and stemness properties in breast cancer cells. Importantly, TMEM97 knockout suppressed tumor growth through downregulating the Wnt/β-catenin signaling pathway in a breast cancer xenograft model. Taken together, our results revealed that TMEM97 is a positive modulator of canonical Wnt signaling. TMEM97-mediated Wnt signaling is implicated in the tumorigenesis of breast cancer, and its targeted inhibition may be a promising therapeutic strategy for breast cancer.

scholarly journals Adipocyte-Derived Leptin Promotes PAI-1-Mediated Breast Cancer Metastasis in a STAT3/miR-34a Dependent Manner

Cancers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3864
Author(s):  
Si-Jing Li ◽  
Xiao-Hui Wei ◽  
Xiao-Man Zhan ◽  
Jin-Yong He ◽  
Yu-Qi Zeng ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cancer Patients ◽  
Breast Cancer Cells ◽  
Cancer Metastasis ◽  
Breast Cancer Metastasis ◽  
Dependent Manner ◽  
Breast Cancer Patients ◽  
Loss Of Function ◽  
Pai 1

The crosstalk between cancer cells and adipocytes is critical for breast cancer progression. However, the molecular mechanisms underlying these interactions have not been fully characterized. In the present study, plasminogen activator inhibitor-1 (PAI-1) was found to be a critical effector of the metastatic behavior of breast cancer cells upon adipocyte coculture. Loss-of-function studies indicated that silencing PAI-1 suppressed cancer cell migration. Furthermore, we found that PAI-1 was closely related to the epithelial-mesenchymal transition (EMT) process in breast cancer patients. A loss-of-function study and a mammary orthotopic implantation metastasis model showed that PAI-1 promoted breast cancer metastasis by affecting the EMT process. In addition, we revealed that leptin/OBR mediated the regulation of PAI-1 through the interactions between adipocytes and breast cancer cells. Mechanistically, we elucidated that leptin/OBR further activated STAT3 to promote PAI-1 expression via miR-34a–dependent and miR-34a–independent mechanisms in breast cancer cells. In conclusion, our study suggests that targeting PAI-1 and interfering with its upstream regulators may benefit breast cancer patients.

scholarly journals Arginine Methyltransferase PRMT1 Regulates p53 Activity in Breast Cancer

Life ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 789
Author(s):  
Li-Ming Liu ◽  
Qiang Tang ◽  
Xin Hu ◽  
Jing-Jing Zhao ◽  
Yuan Zhang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Growth ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Asymmetric Dimethylarginine ◽  
Human Cancer ◽  
Specific Inhibitor ◽  
Dependent Manner ◽  
Breast Tumorigenesis ◽  
Stress Signals

The protein p53 is one of the most important tumor suppressors, responding to a variety of stress signals. Mutations in p53 occur in about half of human cancer cases, and dysregulation of the p53 function by epigenetic modifiers and modifications is prevalent in a large proportion of the remainder. PRMT1 is the main enzyme responsible for the generation of asymmetric-dimethylarginine, whose upregulation or aberrant splicing has been observed in many types of malignancies. Here, we demonstrate that p53 function is regulated by PRMT1 in breast cancer cells. PRMT1 knockdown activated the p53 signal pathway and induced cell growth-arrest and senescence. PRMT1 could directly bind to p53 and inhibit the transcriptional activity of p53 in an enzymatically dependent manner, resulting in a decrease in the expression levels of several key downstream targets of the p53 pathway. We were able to detect p53 asymmetric-dimethylarginine signals in breast cancer cells and breast cancer tissues from patients, and the signals could be significantly weakened by silencing of PRMT1 with shRNA, or inhibiting PRMT1 activity with a specific inhibitor. Furthermore, PRMT1 inhibitors significantly impeded cell growth and promoted cellular senescence in breast cancer cells and primary tumor cells. These results indicate an important role of PRMT1 in the regulation of p53 function in breast tumorigenesis.

scholarly journals Biomechanical regulation of breast cancer metastasis and progression

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adrianne Spencer ◽  
Andrew D. Sligar ◽  
Daniel Chavarria ◽  
Jason Lee ◽  
Darshil Choksi ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Cancer Metastasis ◽  
Mechanical Load ◽  
Breast Cancer Metastasis ◽  
Proliferation And Metastasis ◽  
Xenograft Models ◽  
Chemotherapeutic Treatment ◽  
Complex Signaling

AbstractPhysical activity has been consistently linked to decreased incidence of breast cancer and a substantial increase in the length of survival of patients with breast cancer. However, the understanding of how applied physical forces directly regulate breast cancer remains limited. We investigated the role of mechanical forces in altering the chemoresistance, proliferation and metastasis of breast cancer cells. We found that applied mechanical tension can dramatically alter gene expression in breast cancer cells, leading to decreased proliferation, increased resistance to chemotherapeutic treatment and enhanced adhesion to inflamed endothelial cells and collagen I under fluidic shear stress. A mechanistic analysis of the pathways involved in these effects supported a complex signaling network that included Abl1, Lck, Jak2 and PI3K to regulate pro-survival signaling and enhancement of adhesion under flow. Studies using mouse xenograft models demonstrated reduced proliferation of breast cancer cells with orthotopic implantation and increased metastasis to the skull when the cancer cells were treated with mechanical load. Using high throughput mechanobiological screens we identified pathways that could be targeted to reduce the effects of load on metastasis and found that the effects of mechanical load on bone colonization could be reduced through treatment with a PI3Kγ inhibitor.

scholarly journals Rb Suppresses Collective Invasion, Circulation and Metastasis of Breast Cancer Cells in CD44-Dependent Manner

PLoS ONE ◽  
2013 ◽  
Vol 8 (12) ◽  
pp. e80590 ◽  
Author(s):  
Kui-Jin Kim ◽  
Alzbeta Godarova ◽  
Kari Seedle ◽  
Min-Ho Kim ◽  
Tan A. Ince ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Dependent Manner ◽  
Collective Invasion

scholarly journals ATP Inhibits Breast Cancer Migration and Bone Metastasis through Down-Regulation of CXCR4 and Purinergic Receptor P2Y11

Cancers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 4293
Author(s):  
Xiaowen Liu ◽  
Manuel A. Riquelme ◽  
Yi Tian ◽  
Dezhi Zhao ◽  
Francisca M. Acosta ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Migration ◽  
Bone Metastasis ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Breast Cancer Cells ◽  
Cxcr4 Expression ◽  
Dependent Manner ◽  
Cancer Cell Migration ◽  
Dose Dependent

ATP released by bone osteocytes is shown to activate purinergic signaling and inhibit the metastasis of breast cancer cells into the bone. However, the underlying molecular mechanism is not well understood. Here, we demonstrate the important roles of the CXCR4 and P2Y11 purinergic receptors in mediating the inhibitory effect of ATP on breast cancer cell migration and bone metastasis. Wound-healing and transwell migration assays showed that non-hydrolysable ATP analogue, ATPγS, inhibited migration of bone-tropic human breast cancer cells in a dose-dependent manner. BzATP, an agonist for P2X7 and an inducer for P2Y11 internalization, had a similar dose-dependent inhibition on cell migration. Both ATPγS and BzATP suppressed the expression of CXCR4, a chemokine receptor known to promote breast cancer bone metastasis, and knocking down CXCR4 expression by siRNA attenuated the inhibitory effect of ATPγS on cancer cell migration. While a P2X7 antagonist A804598 had no effect on the impact of ATPγS on cell migration, antagonizing P2Y11 by NF157 ablated the effect of ATPγS. Moreover, the reduction in P2Y11 expression by siRNA decreased cancer cell migration and abolished the impact of ATPγS on cell migration and CXCR4 expression. Similar to the effect of ATPγS on cell migration, antagonizing P2Y11 inhibited bone-tropic breast cancer cell migration in a dose-dependent manner. An in vivo study using an intratibial bone metastatic model showed that ATPγS inhibited breast cancer growth in the bone. Taken together, these results suggest that ATP inhibits bone-tropic breast cancer cells by down-regulating the P2Y11 purinergic receptor and the down-regulation of CXCR4 expression.

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