Role of GRP78 in promoting therapeutic-resistant breast cancer.
Ontology highlight
ABSTRACT:
SUBMITTER: Cook KL
PROVIDER: S-EPMC4600199 | biostudies-other | 2015 Aug
REPOSITORIES: biostudies-other
Publications
Role of GRP78 in promoting therapeutic-resistant breast cancer.
Cook Katherine L KL Clarke Robert R
Future medicinal chemistry 20150824 12
Over 230,000 new cases of invasive breast cancer are diagnosed annually within the USA. Recurrent breast cancer remains a mostly incurable disease with drug resistance, tumor latency and distant metastases driving breast tumor recurrence and morbidity. Understanding drug resistance is a critical component of combating breast cancer. Recently, the protein chaperone GRP78 and the unfolded protein response were implicated as drivers of drug resistance. Preclinical studies show inhibiting GRP78 can ...[more]
Similar Datasets
Project description: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.
| S-EPMC6696983 | biostudies-literature
Project description:HER2 is overexpressed in about 20% of breast cancers and contributes to poor prognosis. Unfortunately, a large fraction of patients have primary or acquired resistance to the HER2-targeted therapy trastuzumab, thus a multi-drug combination is utilized in the clinic, putting significant burden on patients. We systematically identified an optimal HER2 siRNA from 76 potential sequences and demonstrated its utility in overcoming intrinsic and acquired resistance to trastuzumab and lapatinib in 18 HER2-positive cancer cell lines. We provided evidence that the drug-resistant cancer maintains dependence on HER2 for survival. Importantly, cell lines did not readily develop resistance following extended treatment with HER2 siRNA. Using our recently developed nanoparticle platform, systemic delivery of HER2 siRNA to trastuzumab-resistant tumors resulted in significant growth inhibition. Moreover, the optimal HER2 siRNA could also silence an exon 16 skipped HER2 splice variant reported to be highly oncogenic and linked to trastuzumab resistance.
| S-EPMC4924747 | biostudies-literature
Project description:Cervical cancer is one of the most common gynecological malignancies, and it has become a crucial public health problem. In the present study, the expression profiles of cervical cancer and normal cervical tissues were downloaded from the Gene Expression Omnibus and The Cancer Genome Atlas databases. Subsequently, the dysregulated long non-coding RNAs (lncRNAs) in cervical cancer were identified using R software Differentially expressed lncRNAs in cervical cancer that were associated with glucose-regulated protein 78 (GRP78) were screened out and the results demonstrated that eight lncRNAs were strongly positively correlated with GRP78. In order to confirm the relationship between GRP78 and candidate lncRNAs, GRP78 small interfering RNA (siRNA) was transfected into HeLa cells. The target lncRNAs that were regulated by GRP78 were then identified by reverse transcription-quantitative PCR and it was revealed that LINC00294 was significantly downregulated following GRP78-knockdown. Subsequently, Gene Set Enrichment Analysis demonstrated that LINC00294 was mainly enriched in regulating the cell cycle and the Hedgehog pathway. Following transfection of HeLa and SiHa cells with LINC00294 siRNA, the cell cycle was arrested at the G0/G1 phase. Western blotting suggested that LINC00294-knockdown downregulated the expression of cell cycle-associated factors (cyclin D, cyclin E and cyclin Dependent kinase 4) and upregulated cell cycle inhibitory factors (p16 and p21). The Hedgehog pathway was inhibited following knockdown of LINC00294 in HeLa and SiHa cells. In summary, LINC00294 induced by GRP78 promoted the progression of cervical cancer by regulating the cell cycle via Hedgehog pathway.
| S-EPMC7517597 | biostudies-literature
Project description:The selective autophagy of damaged mitochondria is called mitophagy. Mitochondrial dysfunction, mitophagy, and apoptosis have been suggested to be interrelated in various human lung carcinomas. Leucine zipper EF-hand-containing transmembrane protein-1 (LETM1) was cloned in an attempt to identify candidate genes for Wolf-Hirschhorn syndrome. LETM1 plays a role in mitochondrial morphology, ion homeostasis, and cell viability. LETM1 has also been shown to be overexpressed in different human cancer tissues, including lung cancer. In the current study, we have provided clear evidence that LETM1 acts as an anchoring protein for the mitochondria-associated ER membrane (MAM). Fragmented mitochondria have been found in lung cancer cells with LETM1 overexpression. In addition, a reduction of mitochondrial membrane potential and significant accumulation of microtubule-associated protein 1 A/1B-light chain 3 punctate, which localizes with Red-Mito, was found in LETM1-overexpressed cells, suggesting that mitophagy is upregulated in these cells. Interestingly, glucose-regulated protein 78 kDa (GRP78; an ER chaperon protein) and glucose-regulated protein 75 kDa (GRP75) were posited to interact with LETM1 in the immunoprecipitated LETM1 of H460 cells. This interaction was enhanced in cells treated with carbonyl cyanide m-chlorophenylhydrazone, a chemical mitophagy inducer. Treatment of cells with honokiol (a GRP78 inhibitor) blocked LETM1-mediated mitophagy, and CRISPR/Cas9-mediated GRP75 knockout inhibited LETM1-induced autophagy. Thus, GRP78 interacts with LETM1. Taken together, these observations support the notion that the complex formation of LETM1/GRP75/GRP78 might be an important step in MAM formation and mitophagy, thus regulating mitochondrial quality control in lung cancer.
| S-EPMC9184611 | biostudies-literature
Project description:The oncogene nuclear receptor coactivator amplified in breast cancer 1 (AIB1) is a transcriptional coactivator, which is overexpressed in various types of human cancers, including breast cancer. However, the molecular mechanisms regulating AIB1 function remain largely unknown. In this study, we present evidence demonstrating that AIB1 is acetylated by MOF in human breast cancer cells. Moreover, we also found that the acetylation of AIB1 enhances its function in promoting breast cancer cell proliferation. We further showed that the acetylation of AIB1 is required for its recruitment to E2F1 target genes by E2F1. More importantly, we found that the acetylation levels of AIB1 are greatly elevated in human breast cancer cells compared with that in non-cancerous cells. Collectively, our results shed light on the molecular mechanisms that regulate AIB1 function in breast cancer.
| S-EPMC5050530 | biostudies-literature
Project description:Approximately one-third of estrogen receptor (ER) positive breast tumors fail to respond to or become resistant to hormonal therapy. Although the mechanisms responsible for hormone resistance are not completely understood, resistance is associated with alterations in ERα; overexpression of proteins that interact with the receptor; and hormone-independent activation of the receptor by growth factor signal transduction pathways. Our previous studies show that in estrogen dependent breast cancer cells, activation of the epidermal growth factor signaling pathway increases intracellular calcium which binds to and activates ERα through sites in the ligand-binding domain of the receptor and that treatment with extracellular calcium increases the concentration of intracellular calcium which activates ERα and induces hormone-independent cell growth. The present study asked whether overexpression of calcium channels contributes to the hormone-independent and -resistant phenotype of breast cancer cells and whether clinically used calcium channel blockers reverse hormone independence and resistance. The results show that hormone-independent and -resistant cells overexpress calcium channels, have high concentrations of intracellular calcium, overexpress estrogen responsive genes and, as expected, grow in the absence of estradiol and that treatment with calcium channel blockers decreased the concentration of intracellular calcium, the expression of estrogen responsive genes and cell growth. More importantly, in hormone-resistant cells, treatment that combined a calcium channel blocker with an antiestrogen reversed resistance to the antiestrogen.
| S-EPMC9682976 | biostudies-literature
Project description:MicroRNAs (miRNAs) are implicated in numerous physiologic and pathologic processes, such as the development of resistance to chemotherapy. Determining the role of miRNAs in these processes is often accomplished through measuring miRNA abundance by polymerase chain reaction, sequencing, or microarrays. We have developed a system for the large-scale monitoring of dynamic miRNA activity and have applied this system to identify the contribution miRNA activity to the development of trastuzumab resistance in a cell model of HER2+ breast cancer. MiRNA activity measurements identified significantly different activity levels between BT474 cells (HER2 + breast cancer) and BT474R cells (HER2 + breast cancer cells selected for resistance to trastuzumab). We created a library of 32 miRNA reporter constructs, which were delivered by lentiviral transduction into cells, and miRNA activity was quantified by bioluminescence imaging. Upon treatment with the bioimmune therapy, trastuzumab, the activity of 11 miRNAs were significantly altered in parental BT474 cells, and 20 miRNAs had significantly altered activity in the therapy-resistant BT474R cell line. A combination of statistical, network and classification analysis was applied to the dynamic data, which identified miR-21 as a controlling factor in trastuzumab response. Our data suggested downregulation of miR-21 activity was associated with resistance, which was confirmed in an additional HER2 + breast cancer cell line, SKBR3. Collectively, the dynamic miRNA activity measurements and analysis provided a system to identify new potential therapeutic targets in treatment-resistant cancers.
| S-EPMC6185764 | biostudies-literature
Project description:The estrogen receptor (ER) pathway plays a critical role in breast cancer development and progression. Endocrine therapy targeting estrogen action is the most important systemic therapy for ER positive breast cancer. However its efficacy is limited by intrinsic and acquired resistance. Mechanisms responsible for endocrine resistance include deregulation of the ER pathway itself, including loss of ER expression, post-translational modification of ER, deregulation of ER co-activators; increased receptor tyrosine kinase signaling leading to activation of various intracellular pathways involved in signal transduction, proliferation and cell survival, including growth factor receptor tyrosine kinases human epidermal growth factor receptor-2, epidermal growth factor receptor, PI3K/AKT/mammalian target of rapamycin (mTOR), Mitogen activated kinase (MAPK)/ERK, fibroblast growth factor receptor, insulin-like growth factor-1 receptor; alterations in cell cycle and apoptotic machinery; Epigenetic modification including dysregulation of DNA methylation, histone modification, and nucleosome remodeling; and altered expression of specific microRNAs. Functional genomics has helped us identify a catalog of genetic and epigenetic alterations that may be exploited as potential therapeutic targets and biomarkers of response. New treatment combinations targeting ER and such oncogenic signaling pathways which block the crosstalk between these pathways have been proven effective in preclinical models. Results of recent clinical studies suggest that subsets of patients benefit from the combination of inhibitor targeting certain oncogenic signaling pathway with endocrine therapy. Especially, inhibition of the mTOR signaling pathway, a key component implicated in mediating multiple signaling cascades, offers a promising approach to restore sensitivity to endocrine therapy in breast cancer. We systematically reviewed important publications cited in PubMed, recent abstracts from ASCO annual meetings and San Antonio Breast Cancer Symposium, and relevant trials registered at ClinicalTrials.gov. We present the molecular mechanisms contributing to endocrine resistance, in particular focusing on the biological rationale for the clinical development of novel targeted agents in endocrine resistant breast cancer. We summarize clinical trials utilizing novel strategies to overcome therapeutic resistance, highlighting the need to better identify the appropriate patients whose diseases are most likely to benefit from these specific strategies.
| S-EPMC4127598 | biostudies-literature
Project description:Metastatic breast cancer (MBC) is an extremely recalcitrant disease capable of bypassing current targeted therapies via engagement of several growth promoting pathways. SH2 containing protein tyrosine phosphatase-2 (SHP2) is an oncogenic phosphatase known to facilitate growth and survival signaling downstream of numerous receptor inputs. Herein, we used inducible genetic depletion and two distinct pharmacological inhibitors to investigate the therapeutic potential of targeting SHP2 in MBC. Cells that acquired resistance to the ErbB kinase inhibitor, neratinib, displayed increased phosphorylation of SHP2 at the Y542 activation site. In addition, higher levels of SHP2 phosphorylation, but not expression, were associated with decreased survival of breast cancer patients. Pharmacological inhibition of SHP2 activity blocked ERK1/2 and AKT signaling generated from exogenous stimulation with FGF2, PDGF, and hGF and readily prevented MBC cell growth induced by these factors. SHP2 was also phosphorylated upon engagement of the extracellular matrix (ECM) via focal adhesion kinase. Consistent with the potential of SHP2-targeted compounds as therapeutic agents, the growth inhibitory property of SHP2 blockade was enhanced in ECM-rich 3D culture environments. In vivo blockade of SHP2 in the adjuvant setting decreased pulmonary metastasis and extended the survival of systemic tumor-bearing mice. Finally, inhibition of SHP2 in combination with FGFR-targeted kinase inhibitors synergistically blocked the growth of MBC cells. Overall, our findings support the conclusion that SHP2 constitutes a shared signaling node allowing MBC cells to simultaneously engage a diversity of growth and survival pathways, including those derived from the ECM.
| S-EPMC7714690 | biostudies-literature
Project description:The G-protein-coupled receptor C-C chemokine receptor 5 (CCR5) functions as a co-receptor for the entry of HIV into immune cells. CCR5 binds promiscuously to a diverse array of ligands initiating cell signaling that includes guided migration. Although well known to be expressed on immune cells, recent studies have shown the induction of CCR5 on the surface of breast cancer epithelial cells. The function of CCR5 on breast cancer epithelial cells includes the induction of aberrant cell survival signaling and tropism towards chemo attractants. As CCR5 is not expressed on normal epithelium, the receptor provides a potential useful target for therapy. Inhibitors of CCR5 (CCR5i), either small molecules (maraviroc, vicriviroc) or humanized monoclonal antibodies (leronlimab) have shown anti-tumor and anti-metastatic properties in preclinical studies. In early clinical studies, reviewed herein, CCR5i have shown promising results and evidence for effects on both the tumor and the anti-tumor immune response. Current clinical studies have therefore included combination therapy approaches with checkpoint inhibitors.
| S-EPMC10526962 | biostudies-literature