scholarly journals Macrophage conditioned media promotes adipocyte cancer-association, which in turn stimulates breast cancer proliferation and migration

Author(s):  
Karin A. Vallega ◽  
Dale B. Bosco ◽  
Yi Ren ◽  
Qing-Xiang Sang

Abstract Background Breast cancer is the most common cancer in women and the leading cause of female cancer deaths worldwide. Obesity causes chronic inflammation and is a risk factor for post-menopausal breast cancer and poor prognosis. Obesity is known to trigger increased infiltration of macrophages into adipose tissue, yet little research has focused on the effects of macrophages in the early stages of breast tumor development in obese patients. In this study, the effects of pro-inflammatory macrophages on breast cancer-adipocyte crosstalk were investigated. Methods An innovative human cell co-culture system was used to model the paracrine interactions among adipocytes, macrophages, and breast cancer cells, and how they can facilitate tumor progression. The effects on human breast cancer cells were examined using cell counts and migration assays. Quantitative reverse-transcription polymerase chain reaction (qRT-PCR) was used to measure the expression levels of several cytokines and proteases to analyze adipocyte cancer-association. Results Macrophage conditioned media intensified the effects of breast cancer-adipocyte crosstalk. More specifically, adipocytes became delipidated and increased production of pro-inflammatory cytokines, even in the absence of breast cancer cells, although the expression levels were highest with all three cell components. As a result, co-cultured breast cancer cells became more aggressive, with increased proliferation and migration potential when compared to adipocyte-breast cancer cell co-cultures treated with unconditioned media. Conclusions Macrophage conditioned media promotes adipocyte cancer-association and production of pro-inflammatory factors. These macrophage-adipocyte paracrine interactions promote human breast cancer cell proliferation and migration. Thus, macrophages may contribute to adipocyte inflammation and cancer-association and promote breast cancer progression.

Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2550
Author(s):  
Wenjing Chen ◽  
Dhwani Patel ◽  
Yuzhi Jia ◽  
Zihao Yu ◽  
Xia Liu ◽  
...  

Protein stability is largely regulated by post-translational modifications, such as ubiquitination, which is mediated by ubiquitin-activating enzyme E1, ubiquitin-conjugating enzyme E2, and ubiquitin ligase E3 with substrate specificity. Membrane-associated RING-CH (MARCH) proteins represent one novel family of transmembrane E3 ligases which target glycoproteins for lysosomal destruction. While most of the MARCH family members are known to degrade membrane proteins in immune cells, their tumor-intrinsic role is largely unknown. In this study, we found that the expression of one MARCH family member, MARCH8, is specifically downregulated in breast cancer tissues and positively correlated with breast cancer survival rate according to bioinformatic analysis of The Cancer Genomic Atlas (TCGA) dataset. MARCH8 protein expression was also lower in a variety of human breast cancer cell lines in comparison to immortalized human mammary epithelial MCF-12A cells. Restoration of MARCH8 expression induced apoptosis in human breast cancer cell lines MDA-MB-231 and BT549. Stable expression of MARCH8 inhibited tumorigenesis and lung metastases of MDA-MB-231 cells in mice. Moreover, we discovered that the breast cancer stem-cell marker and metastasis driver CD44, a membrane protein, interacts with MARCH8 and is one of the glycoprotein targets subject to MARCH8-dependent lysosomal degradation. Unexpectedly, we identified a nonmembrane protein, signal transducer and transcription activator 3 (STAT3), as another essential ubiquitination target of MARCH8, whose degradation through the proteasome pathway is responsible for the proapoptotic changes mediated by MARCH8. These findings highlight a novel tumor-suppressing function of MARCH8 in targeting both membrane and nonmembrane protein targets required for the survival and metastasis of breast cancer cells.


2020 ◽  
Vol 98 (3) ◽  
pp. 338-344 ◽  
Author(s):  
Yanyan Wu ◽  
Qing-Jun Bi ◽  
Rui Han ◽  
Yajie Zhang

In this work, we investigated the expression pattern and regulatory function of long noncoding RNA (lncRNA) KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1) in breast cancer. We found that KCNQ1OT1 was significantly upregulated in breast cancer cell lines. In lentiviral-transduced BT-549 and HCC1599 cells, KCNQ1OT1 knockdown impaired cancer cell functions, including in vitro proliferation and migration, and in vivo transplant growth. The possible sponging target of KCNQ1OT1, human microRNA-107 (hsa-miR-107), was confirmed to be bound by KCNQ1OT1, and was upregulated in breast cancer cells with KCNQ1OT1 downregulation. Further, hsa-miR-107 knockdown in KCNQ1OT1-downregulated cancer cells reversed its impairing effects on cancer cell proliferation and migration in vitro. Thus, loss of KCNQ1OT1 is associated with functional impairment in breast cancer cells, likely through inverse regulation of its sponging target, hsa-miR-107.


2016 ◽  
Vol 36 (6) ◽  
Author(s):  
Deqiang Wang ◽  
Ping Wu ◽  
Hui Wang ◽  
Lei Zhu ◽  
Wei Zhao ◽  
...  

Stress-activated protein kinase (SAPK) interacting protein 1 (SIN1) is an essential TORC2 component and a key regulator of Akt pathway that plays an important role in various pathological conditions including cancer. Whereas its functional role in breast cancer has not been well characterized. In the present study, SIN1 is associated with the progression and survival of breast cancer patients, as well as human breast cancer cell proliferation and migration. SIN1 mRNA level was significantly up-regulated in human breast cancer samples compared with their corresponding paracancerous histological normal tissues. Furthermore, the expression levels of SIN1 were also increased in three human breast cancer cell lines compared with human breast epithelial cell MCF10A. Overexpression of SIN1 promoted cell proliferation, colony formation and migration of breast cancer cells. Knockdown of SIN1 in MDA-MB-468 cells inhibited cell proliferation, colony formation and migration. In addition, SIN1 overexpression increased phosphorylation of Akt and knockdown of SIN1 inhibited phosphorylation of Akt in MDA-MB-468 cells. In a tumour xenograft model, overexpression of SIN1 promoted tumour growth of MDA-MB-468 cells in vivo, whereas SIN1 knockdown inhibits the tumour growth. Taken together, our results reveal that SIN1 plays an important role in breast cancer and SIN1 is a potential biomarker and a promising target in the treatment of breast cancer.


Author(s):  
Wuqin Xu ◽  
Zihe Xing ◽  
Peng Zhang ◽  
Wuqin Xu

Previous reports indicated that long noncoding RNA 662 (LINC00662) plays a crucial role in several human cancers. Here, we studied the expression pattern of LINC00662 and explored its function in human breast cancer. The expression level of LINC00662 was determined in human breast cancer cell lines and tissues by real-time quantitative polymerase chain reaction (RT-qPCR). Cytoplasmic and nuclear RNA from MDA-MB-157 cells were extracted to analyze the subcellular location of LINC00662. Moreover, the MTT assay, wound-healing assay, colony-forming assay and transwell assay were employed in MDA-MB-157 cells to detect the effect of LINC00662 on cell apoptosis, invasion, migration and proliferation, respectively. LINC00662-specific miRNA and miRNA-gene axis were examined in a dual-luciferase reporter assay and Western blot. We found that LINC00662 was overexpressed in both breast cancer cell lines and tissue compared to normal breast cell lines and healthy breast tissue. Analysis of subcellular localization revealed that LINC00662 was mainly found in the cytoplasm. Furthermore, LINC00662 silencing reduced cell viability and inhibited the proliferation, migration and invasion of MDA-MB-157 cells. Bioinformatics analysis predicted that LNC00662 binds to miR-497-5p. A series of studies confirmed that LINC00662 directly interacted with miR-497-5p and downregulated its expression in MDA-MB-157 cells. MiR-497-5p knockdown significantly reversed the inhibitory effect of shLINC00662. Moreover, egl-9 family hypoxia inducible factor 2 (EglN2) was verified as a target of miR-497-5p. Overall, our results demonstrated that overexpression of LINC00662 accelerated the malignant growth of breast cancer cells via sponging miR-497-5p and upregulating EglN2 expression, and indicate that targeting LINC00662 may represent a novel strategy for breast cancer therapy.


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