SIRT1 against breast cancer through downregulating Bcl-2 protein.

2012 ◽  
Vol 30 (27_suppl) ◽  
pp. 34-34
Author(s):  
Dar-Ren Chen

34 Background: SIRT1, a member of the class III histone deacetylase (HDAC) family, is the mammalian orthologue of yeast Sir2. It has been reported to play a key role in a variety of physiological processes such as genomic stability, metabolism, neurogenesis and cell survival due to its ability to deacetylate both histone and numerous non-histone substrates. The deacetylase function of SIRT1 has been suggested as playing a role in prolonging the life of mammals. However, the suggested functions of SIRT1 as a potential tumor promoter have been challenged by observations of their respective down- and up-regulation in various cancers. The aim of the present study was to simultaneously evaluate the expression levels of SIRT1 and Ki67, the index of cellular proliferation, in normal and tumor tissues of the breast from 27 breast cancer patients and to determine the role of SIRT1 in breast tumorigenesis. Methods: A total of 27 breast cancer patients were included. Tumor tissues and matched normal breast tissues were immediately frozen after collection between 2007 and 2008. Immunohistochemistry and reverse transcription-polymerase chain reaction were applied for analyses of patients’ specimens. Cell proliferation assay, cell cycle analysis and Western blotting were used to investigate the effects of sirtinol on the human breast cancer lines MCF-7 and MDA-MB-231 cells. Results: Immunohistochemistry showed that there is a high correlation between SIRT1 and Ki67 expression. In addition, our results showed that inhibition of SIRT1 induces anti-cell growth in both MCF-7 (ER-positive, non-invasive) and MDA-MB-231 (ER-negative, invasive) breast cancer cell lines, especially in MDA-MB-231 cells. The levels of pro-survival protein Bcl-2 were dramatically decreased in both breast cell lines following sirtinol treatment. Conclusions: Our present study revealed that inhibition of SIRT1 activity may be a promising chemotherapeutic strategy against breast cancer.

2021 ◽  
Vol 11 ◽  
Author(s):  
Xin Hua ◽  
Zhi-Qing Long ◽  
Ling Guo ◽  
Wen Wen ◽  
Xin Huang ◽  
...  

Background: IQ motif-containing GTPase activating protein 3 (IQGAP3), the latest identified member of the IQGAP family, may act as a crucial factor in cancer development and progression; however, its clinical value in breast cancer remains unestablished. We explored the correlation between IQGAP3 expression profile and the clinicopathological features in breast cancer.Methods: IQGAP3 mRNA and protein levels were detected in breast cancer cell lines and tumor tissues by real-time PCR and western blotting and compared to the normal control groups. Protein expression of IQGAP3 was also evaluated immunohistochemically in archived paraffin-embedded specimens from 257 breast cancer patients, and the associations between IQGAP3 expression level, clinical characteristics, and prognosis were analyzed. We assessed the relationship between IQGAP3 expression and sensitivity to radiation therapy which was determined by subgroup analysis.Results: IQGAP3 was significantly upregulated in breast cancer cell lines and human tumor tissues at both the mRNA and protein level compared to controls. Additionally, high levels of IQGAP3 expression were detected in 110/257 (42.8%) of archived paraffin-embedded breast cancer specimens. High IQGAP3 expression level was significantly related to clinical stage (p = 0.001), T category (p = 0.002), N category (p = 0.001), locoregional recurrence (p = 0.002), distant metastasis (p = 0.001), and vital status (p = 0.001). Univariate and multivariate statistical analysis showed that IQGAP3 expression was an independent prognostic factor among all 257 breast cancer patients in our cohort (p = 0.003, p = 0.001). Subgroup analysis revealed IQGAP3 expression correlated with radioresistance and was also an independent predictor of radiotherapy outcome.Conclusion: Our findings suggest that high IQGAP3 expression predicts poor prognosis and radioresistance in breast cancer. Therefore, IQGAP3 may be a reliable prognostic biomarker in breast cancer and could be used to identify patients who may benefit from radiotherapy.


2021 ◽  
Vol 22 (10) ◽  
pp. 5382
Author(s):  
Pei-Yi Chu ◽  
Hsing-Ju Wu ◽  
Shin-Mae Wang ◽  
Po-Ming Chen ◽  
Feng-Yao Tang ◽  
...  

(1) Background: methionine cycle is not only essential for cancer cell proliferation but is also critical for metabolic reprogramming, a cancer hallmark. Hepatic and extrahepatic tissues methionine adenosyltransferases (MATs) are products of two genes, MAT1A and MAT2A that catalyze the formation of S-adenosylmethionine (SAM), the principal biological methyl donor. Glycine N-methyltransferase (GNMT) further utilizes SAM for sarcosine formation, thus it regulates the ratio of SAM:S-adenosylhomocysteine (SAH). (2) Methods: by analyzing the TCGA/GTEx datasets available within GEPIA2, we discovered that breast cancer patients with higher MAT2A had worse survival rate (p = 0.0057). Protein expression pattern of MAT1AA, MAT2A and GNMT were investigated in the tissue microarray in our own cohort (n = 252) by immunohistochemistry. MAT2A C/N expression ratio and cell invasion activity were further investigated in a panel of breast cancer cell lines. (3) Results: GNMT and MAT1A were detected in the cytoplasm, whereas MAT2A showed both cytoplasmic and nuclear immunoreactivity. Neither GNMT nor MAT1A protein expression was associated with patient survival rate in our cohort. Kaplan–Meier survival curves showed that a higher cytoplasmic/nuclear (C/N) MAT2A protein expression ratio correlated with poor overall survival (5 year survival rate: 93.7% vs. 83.3%, C/N ratio ≥ 1.0 vs. C/N ratio < 1.0, log-rank p = 0.004). Accordingly, a MAT2A C/N expression ratio ≥ 1.0 was determined as an independent risk factor by Cox regression analysis (hazard ratio = 2.771, p = 0.018, n = 252). In vitro studies found that breast cancer cell lines with a higher MAT2A C/N ratio were more invasive. (4) Conclusions: the subcellular localization of MAT2A may affect its functions, and elevated MAT2A C/N ratio in breast cancer cells is associated with increased invasiveness. MAT2A C/N expression ratio determined by IHC staining could serve as a novel independent prognostic marker for breast cancer.


Cancers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 2
Author(s):  
Lee D. Gibbs ◽  
Kelsey Mansheim ◽  
Sayantan Maji ◽  
Rajesh Nandy ◽  
Cheryl M. Lewis ◽  
...  

Increasing evidence suggests that AnxA2 contributes to invasion and metastasis of breast cancer. However, the clinical significance of AnxA2 expression in breast cancer has not been reported. The expression of AnxA2 in cell lines, tumor tissues, and serum samples of breast cancer patients were analyzed by immunoblotting, immunohistochemistry, and enzyme-linked immunosorbent assay, respectively. We found that AnxA2 was significantly upregulated in tumor tissues and serum samples of breast cancer patients compared with normal controls. The high expression of serum AnxA2 was significantly associated with tumor grades and poor survival of the breast cancer patients. Based on molecular subtypes, AnxA2 expression was significantly elevated in tumor tissues and serum samples of triple-negative breast cancer (TNBC) patients compared with other breast cancer subtypes. Our analyses on breast cancer cell lines demonstrated that secretion of AnxA2 is associated with its tyrosine 23 (Tyr23) phosphorylation in cells. The expression of non-phosphomimetic mutant of AnxA2 in HCC1395 cells inhibits its secretion from cells compared to wild-type AnxA2, which further suggest that Tyr23 phosphorylation is a critical step for AnxA2 secretion from TNBC cells. Our analysis of AnxA2 phosphorylation in clinical samples further confirmed that the phosphorylation of AnxA2 at Tyr23 was high in tumor tissues of TNBC patients compared to matched adjacent non-tumorigenic breast tissues. Furthermore, we observed that the diagnostic value of serum AnxA2 was significantly high in TNBC compared with other breast cancer subtypes. These findings suggest that serum AnxA2 concentration could be a potential diagnostic biomarker for TNBC patients.


2005 ◽  
Vol 12 (3) ◽  
pp. 599-614 ◽  
Author(s):  
T Frogne ◽  
J S Jepsen ◽  
S S Larsen ◽  
C K Fog ◽  
B L Brockdorff ◽  
...  

Development of acquired resistance to antiestrogens is a major clinical problem in endocrine treatment of breast cancer patients. The IGF system plays a profound role in many cancer types, including breast cancer. Thus, overexpression and/or constitutive activation of the IGF-I receptor (IGF-IR) or different components of the IGF-IR signaling pathway have been reported to render breast cancer cells less estrogen dependent and capable of sustaining cell proliferation in the presence of antiestrogens. In this study, growth of the antiestrogen-sensitive human breast cancer cell line MCF-7 was inhibited by treatment with IGF-IR-neutralizing antibodies. In contrast, IGF-IR-neutralizing antibodies had no effect on growth of two different antiestrogen-resistant MCF-7 sublines. A panel of antiestrogen-resistant cell lines was investigated for expression of IGF-IR and either undetectable or severely reduced IGF-IR levels were observed. No increase in insulin receptor substrate 1 (IRS-1) or total PKB/Akt (Akt) was detected in the resistant cell lines. However, a significant increase in phosphorylated Akt (pAkt) was found in four of six antiestrogen-resistant cell lines. Overexpression of pAkt was associated with increased Akt kinase activity in both a tamoxifen- and an ICI 182,780-resistant cell line. Inhibition of Akt phosphorylation by the phosphatidylinositol 3-kinase (PI3-K) inhibitor wortmannin or the Akt inhibitor SH-6 (structurally modified phosphatidyl inositol ether liquid analog PIA 6) resulted in a more pronounced growth inhibitory effect on the antiestrogen-resistant cells compared with the parental cells, suggesting that signaling via Akt is required for antiestrogen-resistant cell growth in at least a subset of our antiestrogen-resistant cell lines. PTEN expression and activity was not decreased in cell lines overexpressing pAkt. Our data demonstrate that Akt is a target for treatment of antiestrogen-resistant breast cancer cell lines and we suggest that antiestrogen-resistant breast cancer patients may benefit from treatment targeted to inhibit Akt signaling.


Cancers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 961 ◽  
Author(s):  
Srimeenakshi Srinivasan ◽  
Biana Godin

Over-expression of Crk-like protein (CrkL), an intracellular adaptor protein, in breast cancer biopsies has been linked to poor prognosis. CrkL can be secreted from cancer cells binding to β1 integrin on the cell membrane. In this study, we evaluated, for the first time, the levels of soluble CrkL in serum of breast cancer patients. Expression of CrkL and secreted fractions from human breast cancer cell lines and clinical patient samples were assessed by immunohistochemistry and Enzyme Linked Immuno-Sorbent Assay (ELISA). CrkL levels in tissues and sera of patients with different disease stages were compared and statistically analyzed by Chi-square test and Student’s t-test. Culture media from human breast cancer cell lines SUM159, MDA-MB231, and MCF7 showed over a 21-, 15-, and 11-fold higher concentration of soluble CrkL as compared to normal breast epithelium cell line MCF10A. Expression of CrkL was elevated in 85% of breast tumor tissue sections. Serum levels of CrkL were significantly higher in breast cancer patients than in healthy donors. All patients with metastatic disease had significantly elevated concentration of soluble CrkL in the serum with on average three-fold increase from the baseline. The data suggest that soluble fraction of CrkL can be further evaluated as a serum biomarker for advanced disease in breast cancer patients.


2020 ◽  
Author(s):  
Noemi Eiro ◽  
Sandra Cid ◽  
Nuria Aguado ◽  
María Fraile ◽  
Jorge Rubén Cabrera ◽  
...  

Abstract Background: Tumor-infiltrating immune cells phenotype is associated with tumor progression. However, little is known about the phenotype of the Peripheral Blood Mononuclear Cells (PBMC) from breast cancer patients. Here, we investigated the expression of MMP1 and MMP11 in PBMC from breast cancer patients and we analyzed gene expression changes upon their interaction with cancer cells and Cancer-Associated Fibroblasts (CAF). Finally, we measured the impact of PBMC in proinflammatory genes expression in normal fibroblast and CAF.Results: Gene expression of MMP1 and MMP11 in PBMC from breast cancer patients (n=54) and control (n=28), and expression of IL1A, IL6, IL17, IFNβ and NFB in breast cancer cell lines (MCF-7 and MDA-MB-231), CAF and in Normal Fibroblasts (NF) were analyzed by qRT-PCR before and after co-culture. Our results show the existence of a group of breast cancer patients (25.9%) with very high levels of MMP11 gene expression in PBMC. Also, we present evidence of increased gene expression of MMP1 and MMP11 in PBMC after co-culture with breast cancer cell lines, NF or CAF. Finally, we show a differential expression profile of inflammatory genes in NF and CAF when co-cultured with control or breast cancer PBMC.Conclusions: We have observed that MMPs expression in PBMC is regulated by the microenvironment, while the expression of inflammatory genes in NF or CAF is differentially regulated by control or breast cancer PBMC. These findings confirm the importance of the interaction and communication between stromal cells and suggest that PBMC would play a role to promote an aggressive tumor behavior.


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