scholarly journals PARP inhibitor increases chemosensitivity by upregulating miR-664b-5p in BRCA1-mutated triple-negative breast cancer

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Wei Song ◽  
Lin Tang ◽  
Yumei Xu ◽  
Jing Xu ◽  
Wenwen Zhang ◽  
...  

Abstract Emerging evidence has shown that adding poly(ADP-ribose) polymerase (PARP) inhibitors to chemotherapy regimens is superior to the control regimens alone in BRCA1-mutated triple-negative breast cancer (TNBC) patients, but their underlying mechanisms have not been fully elucidated. In this study, using miRNA microarray analysis of two BRCA1-mutated TNBC cell lines, we found that miR-664b-5p expression was increased after adding a PARP inhibitor, olaparib, to a carboplatin (CBP) plus gemcitabine (GEM) therapy regimen. Functional assays showed miR-664b-5p overexpression inhibited proliferation, migration and invasion in BRCA1-mutated TNBC cells. CCNE2 was identified as a novel functional target of miR-664b-5p, and CCNE2 knockdown revealed effects similar to those observed with miR-664b-5p overexpression. Both CCNE2 knockdown and miR-664b-5p overexpression significantly increased the chemosensitivity of BRCA1-mutated TNBC cells. In addition, in vivo studies indicated that miR-664b-5p inhibited tumour growth compared with the control in tumour xenograft models, and we also found that CCNE2 expression was inversely correlated with miR-664b-5p expression in 90 TNBC patient samples. In conclusion, miR-664b-5p functions as a tumour suppressor and has an important role in the regulation of PARP inhibitors to increase chemosensitivity by targeting CCNE2. This may be one of the possible mechanisms by which PARP inhibitors increase chemosensitivity in BRCA1-mutated TNBC.

2021 ◽  
Vol 11 ◽  
Author(s):  
Wenhui Guo ◽  
Jingyi Li ◽  
Haobo Huang ◽  
Fangmeng Fu ◽  
Yuxiang Lin ◽  
...  

Long non-coding RNAs (LncRNA) as the key regulators in all stages of tumorigenesis and metastasis. However, the underlying mechanisms are largely unknown. Here, we report a lncRNA RP11-214F16.8, which renamed Lnc-PCIR, is upregulated and higher RNA level of Lnc-PCIR was positively correlated to the poor survival of patients with triple negative breast cancer (TNBC) tissues. Lnc-PCIR overexpression significantly promoted cell proliferation, migration, and invasion in vitro and in vivo. RNA pulldown, RNA immunoprecipitation (RIP) and RNA transcriptome sequencing technology (RNA-seq) was performed to identify the associated proteins and related signaling pathways. Mechanistically, higher Lnc-PCIR level of blocks PABPC4 proteasome-dependent ubiquitination degradation; stable and highly expressed PABPC4 can further increase the stability of TAB3 mRNA, meanwhile, overexpression of Lnc-PCIR can disrupt the binding status of TAB3 and TAB2 which lead to activate the TNF-α/NF-κB pathway in TNBC cells. Our findings suggest that Lnc-PCIR promotes tumor growth and metastasis via up-regulating the mRNA/protein level of TAB3 and PABPC4, activating TNF-α/NF-κB signaling pathway in TNBC.


BMC Cancer ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Pradip Shahi Thakuri ◽  
Megha Gupta ◽  
Sunil Singh ◽  
Ramila Joshi ◽  
Eric Glasgow ◽  
...  

Abstract Background Cell migration and invasion are essential processes for metastatic dissemination of cancer cells. Significant progress has been made in developing new therapies against oncogenic signaling to eliminate cancer cells and shrink tumors. However, inherent heterogeneity and treatment-induced adaptation to drugs commonly enable subsets of cancer cells to survive therapy. In addition to local recurrence, these cells escape a primary tumor and migrate through the stroma to access the circulation and metastasize to different organs, leading to an incurable disease. As such, therapeutics that block migration and invasion of cancer cells may inhibit or reduce metastasis and significantly improve cancer therapy. This is particularly more important for cancers, such as triple negative breast cancer, that currently lack targeted drugs. Methods We used cell migration, 3D invasion, zebrafish metastasis model, and phosphorylation analysis of 43 protein kinases in nine triple negative breast cancer (TNBC) cell lines to study effects of fisetin and quercetin on inhibition of TNBC cell migration, invasion, and metastasis. Results Fisetin and quercetin were highly effective against migration of all nine TNBC cell lines with up to 76 and 74% inhibitory effects, respectively. In addition, treatments significantly reduced 3D invasion of highly motile TNBC cells from spheroids into a collagen matrix and their metastasis in vivo. Fisetin and quercetin commonly targeted different components and substrates of the oncogenic PI3K/AKT pathway and significantly reduced their activities. Additionally, both compounds disrupted activities of several protein kinases in MAPK and STAT pathways. We used molecular inhibitors specific to these signaling proteins to establish the migration-inhibitory role of the two phytochemicals against TNBC cells. Conclusions We established that fisetin and quercetin potently inhibit migration of metastatic TNBC cells by interfering with activities of oncogenic protein kinases in multiple pathways.


Author(s):  
Yihong Huang ◽  
Shuo Zheng ◽  
Ying Lin ◽  
Liming Ke

Triple negative breast cancer (TNBC) is an aggressive histological subtype of breast cancer. It has been reported that that circRNA circ-ERBB2 (circBase ID: hsa_circ_0007766) is mainly distributed in the cytoplasm of TNBC cells and promotes the proliferation and invasion of TNBC cells. This study aimed to explore the molecular mechanism of circ-ERBB2 regulating the progression of TNBC. Expression of circ-ERBB2 was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Loss-of-function experiments were performed to investigate the function of circ-ERBB2 in TNBC cells in vitro and in vivo . The regulatory mechanism of circ-ERBB2 was surveyed by bioinformatics analysis, dual-luciferase reporter and RNA immunoprecipitation (RIP) or RNA pull-down assays. We observed that Circ-ERBB2 was overexpressed in TNBC, and TNBC patients with high circ-ERBB2 expression had a poor prognosis. Functionally, circ-ERBB2 knockdown constrained TNBC growth in vivo and reduced Warburg effect, accelerated apoptosis, repressed proliferation, migration, and invasion of TNBC cell in vitro . Mechanically, circ-ERBB2 sponged miR-136-5p to elevate pyruvate dehydrogenase kinase 4 (PDK4) expression. In conclusion, circ-ERBB2 facilitated Warburg effect and malignancy of TNBC cells by the miR-136-5p/PDK4 pathway, at least in part. This study supported circ-ERBB2 as a prognostic indicator for TNBC.


2019 ◽  
Vol 7 ◽  
pp. 232470961986498 ◽  
Author(s):  
Trevanne Matthews Hew ◽  
Lara Zuberi

Triple-negative breast cancer (TNBC) accounts for 20% of breast cancers diagnosed worldwide. This subtype of breast cancer tends to behave more aggressively, and unlike other breast cancer subtypes, there are no standard targeted treatments for most patients. However, up to 20% of patients with TNBC harbor a breast cancer gene (BRCA) mutation, particularly in BRCA1. For patients who carry this gene mutation, this opens the door for new management options by the use of newer agents such as polyadenosine diphosphate-ribose polymerase (PARP) inhibitors in the metastatic setting. Given that this is uncommon and that PARP inhibitors have only recently received Federal Drug Administration approval, the experience with these drugs is relatively new. In this article, we present a case of a patient treated in this setting with olaparib who developed an unanticipated side effect as a result of the high efficacy of the drug.


2021 ◽  
Vol 12 ◽  
Author(s):  
Chenyang Xue ◽  
Wei Chen ◽  
Aiwu Yuan ◽  
Cheng Chen ◽  
Shuaihu Li ◽  
...  

Opioids are a potential adjuvant treatment for certain cancers; while they are primarily used to relieve chronic pain, these drugs may also affect cancer progression and recurrence. Dezocine is one opioid commonly used in China, but its effects on cancer cells are unknown. Here, we demonstrated the inhibitory effect of dezocine on triple-negative breast cancer (TNBC) cells, and determined the underlying molecular mechanism. We found that dezocine suppressed cell proliferation, migration and invasion, and induced apoptosis in TNBC cells. Xenograft models demonstrated the inhibitory effects of dezocine treatment on TNBC tumor growth in vivo. The anticancer effects of dezocine were independent of opioid receptors, which are not highly expressed by normal breast or breast cancer tissues. A pull-down assay and LC-MS/MS analysis indicated that dezocine directly targets NAMPT: computer modeling verified that the free energy of dezocine kinetically bound into the pocket of NAMPT was −17.4 kcal/mol. Consequently, dezocine treatment inhibited NAMPT enzyme activity, resulting in cellular NAD abolishment. We confirmed the dezocine-induced inhibition of cell proliferation by both NAMPT knockdown and upon treatment with the inhibitor FK866. Our results suggest that both dezocine and NAMPT might represent novel therapeutic targets for TNBC.


Epigenomics ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1163-1176 ◽  
Author(s):  
Yanan Kong ◽  
Lu Yang ◽  
Weidong Wei ◽  
Ning Lyu ◽  
Yutian Zou ◽  
...  

Aim: To investigate the role of circRNAs in triple-negative breast cancer (TNBC) and the underlying mechanisms. Materials & methods: We performed circRNA microarrays to explore the expression profiles of TNBC cell lines. Experiments in vitro and in vivo were conducted to explore the effects of circPLK1 on tumor proliferation and metastasis as well as the interaction between circPLK1, miR-296-5p and PLK1 in TNBC. Results & conclusion: CircPLK1 was significantly upregulated in TNBC and associated with poor survivals. CircPLK1 knockdown inhibited cell growth and invasion in vitro as well as tumor occurrence and metastasis in vivo. CircPLK1-miR-296-5p- PLK1 axis regulates tumor progression by ceRNA mechanism in TNBC, indicating that circPLK1 may serve as a prognostic factor and novel therapeutic target for TNBC.


Tumor Biology ◽  
2020 ◽  
Vol 42 (4) ◽  
pp. 101042832091447 ◽  
Author(s):  
Nirmala Jagadish ◽  
Sonika Devi ◽  
Namita Gupta ◽  
Vitusha Suri ◽  
Anil Suri

Triple-negative breast cancers are the most aggressive subtypes with poor prognosis due to lack of targeted cancer therapy. Recently, we reported an association of A-kinase anchor protein 4 expression with various clinico-pathological parameters of breast cancer patients. In this context, we examined the effect of knockdown of A-kinase anchor protein 4 on cell cycle, apoptosis, cellular proliferation, colony formation, migration, and invasion in triple-negative breast cancer cells. We also examined the synergistic cytotoxic effect of paclitaxel on A-kinase anchor protein 4 downregulated triple-negative breast cancer cells. Knockdown of A-kinase anchor protein 4 resulted in significant reduction in cellular growth and migratory abilities. Interestingly, we also observed enhanced cell death in A-kinase anchor protein 4 downregulated cells treated with paclitaxel. Knockdown of A-kinase anchor protein 4 in cell cycle resulted in G0/G1 phase arrest. Knockdown of A-kinase anchor protein 4 also led to increased reactive oxygen species generation as a result of upregulation of NOXA and CHOP. In addition, levels of cyclins, cyclin-dependent kinases, anti-apoptotic molecules, and mesenchymal markers were reduced in A-kinase anchor protein 4 downregulated cells. Moreover, downregulation of A-kinase anchor protein 4 also caused tumor growth reduction in in vivo studies. These data together suggest that A-kinase anchor protein 4 downregulation inhibits various malignant properties and enhances the cytotoxic effect of paclitaxel, and this combinatorial approach could be useful for triple-negative breast cancer treatment.


2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 1063-1063 ◽  
Author(s):  
Ye Han ◽  
Chia-Wei Li

1063 Background: Poly (ADP-ribose) polymerase (PARP) inhibitors have emerged as promising targeted therapies for BRCA-mutated cancers by blocking repair of DNA double-strand breaks. However, resistance to PARP inhibitors have been described in some patients lowering overall response rates. The mechanisms underlying PARP inhibitor (PARPi) resistance are an area of active investigation. Methods: PARPi adaptive resistant clones (MDA-MB-468, MDA-MB-231, HCC1806) were generated in triple-negative breast cancer cell lines. Through morphologic observation and functional analysis, we evaluated epithelial-mesenchymal transition (EMT) and changes in immune checkpoint programmed death-ligand 1 (PD-L1). We also downregulated the expression of PD-L1 by shRNA to study the role of PD-L1 in PARPi resistance. We evaluated the immunology sensitivity to cytotoxic T cell upon PD-L1 change using a murine ex-vivo CD8+ T cell killing assay and a comparison of total killing cells percentage per well. Results: We demonstrated that inhibition of PARP enhances EMT, which induces phosphorylation of Akt at S473. This in turn upregulates the expression of PD-L1 by 2-3 fold in triple-negative breast cancer cells. In addition, PARPi–induced EMT occurred independent of PD-L1 upregulation in triple-negative breast cancer cells. Metformin administration (10µM) was found to reverse EMT by blocking the p-Akt S473 axis through activation of AMPK, resulting in downregulation of PD-L1 expression and sensitizing PARPi-resistant cancer cells to T cell killing. Conclusions: In summary, we identified that induction of EMT is a new mechanism for PARP inhibitor resistance. Metformin was able to reverse EMT and therefore a combination of metformin and PARP inhibitors may be a promising therapeutic strategy to increase the efficacy of PARP inhibitors and tumor sensitivity to T cells.


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