scholarly journals PLAC8 promotes adriamycin resistance via  blocking  autophagy in breast cancer

2020 ◽  
Author(s):  
yongxia chen ◽  
yunlu jia ◽  
misha mao ◽  
Yifeng Gu ◽  
Chenpu Xu ◽  
...  

Abstract Background Adriamycin (ADM) is currently one of the most effective chemotherapeutic agents in breast cancer treatment. However, growing resistance to ADM can lead to treatment failure and poor outcome. The underlying molecular mechanisms in ADM resistance in breast cancer remains unclear. PLAC8 is reported as a novel highly-conserved protein and functions as an oncogene or tumor suppressor in various tumors. Methods Here, we analyzed the expression profile of PLAC8 in breast cancer tissues and breast cancer cell lines, and explored the correlation of PLAC8 expression levels with patients’ outcomes and ADM response. One ADM resistant MCF-7 breast cancer cell (MCF-7/ADM) and its parental cell was used as in vitro models to identify the underlying mechanism of PLAC8 and ADM resistance. Breast cancer cells were transfected with PLAC8 knockdown and overexpression vectors, and MTT and colony formation assays were performed to test the cell response to ADM. Then, we tested the effect of PLAC8 on autophagy pathway by flow cytometry and immunofluorescence analysis, and the change of main autophagy-correlated factors expressions: LC3 and p62. Next, combining treatment of autophagy inhibitor/inducer and PLAC8 downregulation/upregulation revealed the participation of PLAC8 in autophagy pathway to synergistically regulate ADM resistance in breast cancer. Results Here, higher PLAC8 expression was correlated with poorer outcome and aggressive phenotype in breast cancer, and breast cancer patients with higher PLAC8 expression showed potential ADM resistance. PLAC8 expression level was also significantly elevated in ADM resistant MCF-7 breast cancer cells (MCF-7/ADM), compared to parental MCF-7 cells. In vitro experiments further confirmed that PLAC8 inhibition by siRNA or enforced overexpression by infecting pcDNA3.1(C)-PLAC8 plasmid correspondingly decreased or increased the ADM resistance. Subsequently, we demonstrated that ectopic PLAC8 expression in MCF-7/ADM cell blocked the accumulation of the autophagy-associated protein LC3II, and resulted in cellular accumulation of p62. Rapamycin-triggered autophagy significantly increased cell response to ADM, while the autophagy inhibitor 3-MA enhanced ADM resistance. Actually, 3-MA and PLAC8 could synergistically enhance ADM resistance via blocking the autophagy process. Additionally, the downregulation of p62 by siRNA attenuated the activation of autophagy and PLAC8 expression in breast cancer cells. Conclusion Our findings suggest that PLAC8, through participation of p62, inhibits autophagy and consequently results in ADM resistance in breast cancer. PLAC8/p62/autophagy pathway may act as novel therapeutic targets in breast cancer treatment and has potential clinical application in overcoming ADM resistance.

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Thandi Mqoco ◽  
André Stander ◽  
Anna-Mart Engelbrecht ◽  
Anna M Joubert

Current chemotherapeutic agents have many side effects and are toxic to normal cells, providing impetus to identify agents that can effectively eliminate tumorigenic cells without damaging healthy cells. The aim of this study was to examine whether combining a novel BRD4 inhibitor, ITH-47, with the antimitotic estradiol analogue, ESE-15-ol, would have a synergistic effect on inhibiting the growth of two different breast cancer cell lines in vitro. Our docking and molecular dynamics studies showed that compared to JQ1, ITH-47 showed a similar binding mode with hydrogen bonds forming between the ligand nitrogens of the pyrazole, ASN99, and water of the BRD4 protein. Data from cell growth studies revealed that the GI50 of ITH-47 and ESE-15-ol after 48 hours of exposure was determined to be 15 μM and 70 nM, respectively, in metastatic MDA-MB-231 breast cancer cells. In tumorigenic MCF-7 breast cancer cells, the GI50 of ITH-47 and ESE-15-ol was 75 μM and 60 nM, respectively, after 48 hours of exposure. Furthermore, the combination of 7.5 μM and 14 nM of ITH-47 and ESE-15-ol, respectively, resulted in 50% growth inhibition of MDA-MB-231 cells resulting in a synergistic combination index (CI) of 0.7. Flow cytometry studies revealed that, compared to the control, combination-treated MDA-MB-231 cells had significantly more cells present in the sub-G1 phase and the combination treatment induced apoptosis in the MDA-MB-231 cells. Compared to vehicle-treated cells, the combination-treated cells showed decreased levels of the BRD4, as well as c-Myc protein after 48 hours of exposure. In combination, the selective BRD4 inhibitor, ITH-47, and ESE-15-ol synergistically inhibited the growth of MDA-MB-231 breast cancer cells, but not of the MCF-7 cell line. This study provides evidence that resistance to BRD4 inhibitors may be overcome by combining inhibitors with other compounds, which may have treatment potential for hormone-independent breast cancers.


2018 ◽  
Vol 47 (6) ◽  
pp. 2199-2215 ◽  
Author(s):  
Jian Hao ◽  
Ziqi Jin ◽  
Hongxu Zhu ◽  
Xiaohui Liu ◽  
Yu Mao ◽  
...  

Background/Aims: The Xi-Huang (XH) formula has been used for breast cancer treatment in traditional Chinese medicine (TCM) since 1740. In this study, we show that, XH extract could suppress the growth of breast cancer cells in vitro and in vivo, and that it preferentially inhibits cell growth of estrogen receptor positive (ER+) breast cancer cells. Presently, little is known about the potential mechanism of XH and our studies aim to elucidate its mechanism in breast cancer treatment. Methods: Network-based systems biology and molecular docking analyses were performed to predict explicit targets of XH and active ingredients in XH. The effects of XH on cell viability, cell cycle, apoptosis in different breast cancer cell lines were analyzed in vitro. A model of transplanted tumors on nude mice was used to study the anticancer effect in vivo. Various techniques, including western blotting, reverse transcription-polymerase chain reaction (RT-PCR), immunofluorescence, co-immunoprecipitation and immunohistochemical were utilized to assess the expression of targets of XH in vitro and in vivo. RNA sequencing (RNA-seq) was performed to study the gene targets of XH. Furthermore, we analyzed of protein-ligand binding reactions by isothermal titration calorimetry (ITC). Results: Using network-based systems biology and molecular docking analyses, we predicted that the major targets of XH were ERα and HSP90. Moreover, we found that, XH mediated its anti-cancer effects by promoting the disassociation of ERα and HSP90, resulting in the degradation of ERα and blockade of transport of ERα to the nucleus. XH also caused the dissociation of ERα and other oncoproteins via binding to HSP90. Some of the active ingredients in XH share a common cyclopentane hydrogen skeleton and were predicted to target ERα based on the structural similarity. Conclusions: XH, which has been used since 1740, has antiestrogenic effects in breast cancer via the targeting of ERα.


2020 ◽  
Vol 21 (14) ◽  
pp. 1528-1538
Author(s):  
Sarah Albogami ◽  
Hadeer Darwish ◽  
Hala M. Abdelmigid ◽  
Saqer Alotaibi ◽  
Ahmed Nour El-Deen ◽  
...  

Background: In Saudi Arabia, the incidence and mortality rates of breast cancer are high. Although current treatments are effective, breast cancer cells develop resistance to these treatments. Numerous studies have demonstrated that active compounds in plant extracts, such as the phenolic compound Rosmarinic Acid (RA), exert anti-cancer effects. Objective: We investigated the anticancer properties of methanolic crude extracts of seedlings and calli of Rosmarinus officinalis and Coleus hybridus, two Lamiaceae species. Methods: MCF-7 human breast cancer cells were treated with methanolic crude extracts obtained from plant calli and seedlings generated in vitro, and cell proliferation was evaluated. Transcriptional profiling of the seedling and callus tissues was also conducted. Results: The mRNA expression levels of RA genes were higher in C. hybridus seedlings than in R. officinalis seedlings, as well as in C. hybridus calli than in R. officinalis calli, except for TAT and C4H. In addition, seedling and callus extracts of both R. officinalis and C. hybridus showed anti-proliferative effects against MCF-7 cells after 24 or 48 h of treatment. Discussion: At a low concentration of 10 μg/mL, C. hybridus calli and seedling extracts showed the most significant anti-proliferative effects after 24 and 48 h of exposure (p < 0.01); controls (doxorubicin) also showed significant inhibition, but lesser than that observed with C. hybridus (p < 0.05). Results with R. officinalis callus and seedling extracts did not significantly differ from those with untreated cells. Conclusion: Methanolic extracts of R. officinalis and C. hybridus are potentially valuable options for breast cancer treatment.


Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2116
Author(s):  
Xiaoyong Wang ◽  
Lijuan Zhang ◽  
Qi Dai ◽  
Hongzong Si ◽  
Longyun Zhang ◽  
...  

The high concentrations of individual phytochemicals in vitro studies cannot be physiologically achieved in humans. Our solution for this concentration gap between in vitro and human studies is to combine two or more phytochemicals. We screened 12 phytochemicals by pairwise combining two compounds at a low level to select combinations exerting the synergistic inhibitory effect of breast cancer cell proliferation. A novel combination of luteolin at 30 μM (LUT30) and indole-3-carbinol 40 μM (I3C40) identified that this combination (L30I40) synergistically constrains ERα+ breast cancer cell (MCF7 and T47D) proliferation only, but not triple-negative breast cancer cells. At the same time, the individual LUT30 and I3C40 do not have this anti-proliferative effect in ERα+ breast cancer cells. Moreover, this combination L30I40 does not have toxicity on endothelial cells compared to the current commercial drugs. Similarly, the combination of LUT and I3C (LUT10 mg + I3C10 mg/kg/day) (IP injection) synergistically suppresses tumor growth in MCF7 cells-derived xenograft mice, but the individual LUT (10 mg/kg/day) and I3C (20 mg/kg/day) do not show an inhibitory effect. This combination synergistically downregulates two major therapeutic targets ERα and cyclin dependent kinase (CDK) 4/6/retinoblastoma (Rb) pathway, both in cultured cells and xenograft tumors. These results provide a solid foundation that a combination of LUT and I3C may be a practical approach to treat ERα+ breast cancer cells after clinical trials.


2021 ◽  
pp. 096032712199945
Author(s):  
AT Aliyev ◽  
S Ozcan-Sezer ◽  
A Akdemir ◽  
H Gurer-Orhan

Apigenin, a flavonoid, is reported to act as an estrogen receptor (ER) agonist and inhibit aromatase enzyme. However, amentoflavone, a biflavonoid bearing two apigenin molecules, has not been evaluated for its endocrine modulatory effects. Besides, it is highly consumed by young people to build muscles, enhance mood and lose weight. In the present study, apigenin was used as a reference molecule and ER mediated as well as ER-independent estrogenic/antiestrogenic activity of amentoflavone was investigated. Antitumor activity of amentoflavone was also investigated in both ER positive (MCF-7 BUS) and triple-negative (MDA-MB-231) breast cancer cells and its cytotoxicity was evaluated in human breast epithelial cells (MCF-10A). Our data confirmed ER agonist, aromatase inhibitory and cytotoxic effects of apigenin in breast cancer cells, where no ER mediated estrogenic effect and physiologically irrelevant, slight, aromatase inhibition was found for amentoflavone. Although selective cytotoxicity of amentoflavone was found in MCF-7 BUS cells, it does not seem to be an alternative to the present cytotoxic drugs. Therefore, neither an adverse effect, mediated by an estrogenic/antiestrogenic effect of amentoflavone nor a therapeutical benefit would be expected from amentoflavone. Further studies could be performed to investigate its in vivo effects.


2021 ◽  
pp. 1-11
Author(s):  
Meng Li ◽  
Wenmin Zhang ◽  
Xiaodan Yang ◽  
Guo An ◽  
Wei Zhao

BACKGROUND: The voltage-gated calcium channel subunit alpha 2 delta 1 (α2δ1) is a functional tumor initial cells (TICs) marker for some solid cancer cells. This study aimed to investigate whether α2δ1 can be used as a potential TIC marker for breast cancer cells. METHODS: α2δ1+ and α2δ1- cells were identified and sorted from the breast cancer cell lines MDA-MB-231, MDA-MB-435s and ZR-75-1 by Immunofluorescence (IF) and Fluorescent-activated cell sorting (FACS) analyses. Spheroid formation in vitro and tumorigenesis in NOD/SCID mice were assessed to determine the self-renewal and serial transplantation abilities of these cells. Using a lentivirus infection system for α2δ1 in breast cancer cell lines, we determined the mRNA levels of stemnessassociated genes by quality real-time PCR (qRT-PCR). Boyden chamber and wounding assays were further performed to detect the migration of α2δ1 overexpression cells. Bioinformatics explored the relationship of molecular classification of breast cancer and drug resistance. RESULTS: α2δ1 presents on the cytomembrane of breast cancer cells, with a positive rate of 1.5–3%. The α2δ1+ cells in breast cancer cell lines have a stronger self-renewal ability and tumor initiating properties in vitro and in vivo. Overexpressing α2δ1 successfully enhanced the sphere-forming efficiency, and upregulated the expression of stemness-associated genes, and increased cell migration. However, seldom significant was available between estrogen receptor +/- (ER+/-), progesterone receptor (PR+/-), and Her2+/-. CONCLUSIONS: Breast cancer cells positive for the α2δ1 charactered tumor initiation, and α2δ1 is a potential TIC marker for breast cancer that further promotes the migration.


2004 ◽  
Vol 32 (3) ◽  
pp. 793-810 ◽  
Author(s):  
MA Greeve ◽  
RK Allan ◽  
JM Harvey ◽  
JM Bentel

Androgens inhibit the growth of breast cancer cells in vitro and in vivo by mechanisms that remain poorly defined. In this study, treatment of asynchronously growing MCF-7 breast cancer cells with the androgen, 5alpha-dihydrotestosterone (DHT), was shown to inhibit cell proliferation and induce moderate increases in the proportion of G1 phase cells. Consistent with targeting the G1-S phase transition, DHT pretreatment of MCF-7 cultures impeded the serum-induced progression of G1-arrested cells into S phase and reduced the kinase activities of cyclin-dependent kinase (Cdk)4 and Cdk2 to less than 50% of controls within 3 days. DHT treatment was associated with greater than twofold increases in the levels of the Cdk inhibitor, p27(Kip1), while p21(Cip1/Waf1) protein levels remained unchanged. During the first 24 h of DHT treatment, levels of Cdk4-associated p21(Cip1/Waf1) and p27(Kip1) were reduced coinciding with decreased levels of Cdk4-associated cyclin D3. In contrast, DHT treatment caused increased accumulation of Cdk2-associated p21(Cip1/Waf1), with no significant alterations in levels of p27(Kip1) bound to Cdk2 complexes. These findings suggest that DHT reverses the Cdk4-mediated titration of p21(Cip1/Waf1) and p27(Kip1) away from Cdk2 complexes, and that the increased association of p21(Cip1/Waf1) with Cdk2 complexes in part mediates the androgen-induced growth inhibition of breast cancer cells.


Author(s):  
Eduardo Ribeiro Almeida ◽  
Helio F. Dos Santos ◽  
Priscila V. S. Z. Capriles

Cisplatin (cddp)-based chemotherapy is one of the most effective therapeutic alternatives for breast cancer treatment, the most common form of cancer, despite the severe side effects related to the high...


2021 ◽  
Vol 11 (2) ◽  
pp. 326-332
Author(s):  
Le Ma ◽  
Zhenyu Liu ◽  
Zhimin Fan

Breast cancer is one of the most prevailing cancers in females, while the cancerous heterogeneity hinders its early diagnosis and subsequent therapy. miR-143-3p is a critical mediator in malignancy development and tumorigenesis as a tumor suppressor. Its role in various tumor entities has been investigated, such as colon cancer and breast cancer. Using MCF-7 breast cancer cell model, we planned to explore the underlying mechanisms of miR-143/KLF-5 axis in retarding breast cancer cells growth. Bioinformatics analysis searched the target KLF5 of miR-143, and the miR-143-targeted mimic and inhibitor were employed to detect the changes of KLF5. After transfection of mimic miR-143, the CCK-8 reagent assessed cell proliferation. Based on optimal stimulation time, miR-143 stimulation model was established, followed by determining expression of KLF5, EGFR and PCNA via western blot and qPCR. Eventually, siRNA-KLF5 was applied to silencing KLF5 level to evaluate its role in MCF-7 cells. The transcription and translation levels of KLF5 were diminished in miR-143-mimic transfected MCF-7 cells, while enhanced in miR-143-inhibitor transfected MCF-7 cells. When MCF-7 cells were transfected with miR-143-mimic at different time points, 48 hours was found to be the optimal transfection time, with reduced transcription and translation levels of KLF5, EGFR and PCNA. The transcription and translation levels of PNCA and EGFR were declined after silencing KLF5 by siRNA. miR-143/KLF5 axis could retard the proliferation of MCF-7 breast cancer cells.


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