1
|
Targeting Amino Acid Metabolic Reprogramming via L-Type Amino Acid Transporter 1 (LAT1) for Endocrine-Resistant Breast Cancer. Cancers (Basel) 2021; 13:cancers13174375. [PMID: 34503187 PMCID: PMC8431153 DOI: 10.3390/cancers13174375] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 08/23/2021] [Accepted: 08/25/2021] [Indexed: 12/22/2022] Open
Abstract
The PI3K/Akt/mTOR pathway has been well known to interact with the estrogen receptor (ER)-pathway and to be also frequently upregulated in aromatase inhibitor (AI)-resistant breast cancer patients. Intracellular levels of free amino acids, especially leucine, regulate the mammalian target of rapamycin complex 1 (mTORC1) activation. L-type amino acid transporters such as LAT1 and LAT3 are associated with the uptake of essential amino acids. LAT1 expression could mediate leucine uptake, mTORC1 signaling, and cell proliferation. Therefore, in this study, we explored amino acid metabolism, including LAT1, in breast cancer and clarified the potential roles of LAT1 in the development of therapeutic resistance and the eventual clinical outcome of the patients. We evaluated LAT1 and LAT3 expression before and after neoadjuvant hormone therapy (NAH) and examined LAT1 function and expression in estrogen deprivation-resistant (EDR) breast carcinoma cell lines. Tumors tended to be in advanced stages in the cases whose LAT1 expression was high. LAT1 expression in the EDR cell lines was upregulated. JPH203, a selective LAT1 inhibitor, demonstrated inhibitory effects on cell proliferation in EDR cells. Hormone therapy changed the tumor microenvironment and resulted in metabolic reprogramming through inducing LAT1 expression. LAT1 expression then mediated leucine uptake, enhanced mTORC1 signaling, and eventually resulted in AI resistance. Therefore, LAT1 could be the potential therapeutic target in AI-resistant breast cancer patients.
Collapse
|
2
|
Suzuki Y, Wenwen W, Ohta T, Hayashi SI. Molecular targeted drugs resistance impairs double-strand break repair and sensitizes ER-positive breast cancer to PARP inhibitors. Breast Cancer 2021; 29:77-91. [PMID: 34346034 DOI: 10.1007/s12282-021-01282-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 08/01/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND There are various treatments for estrogen-positive breast cancer, mainly hormone therapy and molecular-targeted drugs. Acquiring resistance to these drugs is a major clinical problem. Additionally, little is known about the effect of drug resistance on the DNA repair mechanism. Poly ADP ribose polymerase (PARP) inhibitors currently used for treating HER2-negative metastatic breast cancer with BRCA mutations have been shown to be effective in BRCA-deficient cells with impaired homologous recombination repair. Here, we investigated the effect of drug resistance acquisition on the DNA repair mechanism and the effect of PARP inhibitors on ER (estrogen receptor) -positive breast cancer. METHODS We investigated changes in the expression of DNA repair mechanism-related factors and repair ability of double-strand breaks (DSB) in various drug-resistant cell lines established in our laboratory. Additionally, PARP inhibitor susceptibility was investigated using olaparib. RESULTS DSB repairs in MCF-7 and hormone therapy-resistant model cells were normal, and these cells demonstrated low sensitivity to olaparib. The resistant cell lines against CDK4/6 inhibitors, fulvestrant and mTOR/PI3K inhibitors showed decreased DSB repair ability and high olaparib sensitivity. They showed low sensitivity to CDK4/6 inhibitors, a close link between acquiring resistance to CDK4/6 inhibitors and hypersensitivity to olaparib. CONCLUSIONS Our study suggests some cases of acquiring drug resistance impairs DSB repair ability and sensitizes ER-positive breast cancer to PARP inhibitors.
Collapse
Affiliation(s)
- Yuna Suzuki
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, 2-1 Seoryo-machi, Aoba-ku, Sendai, 980-8575, Japan
| | - Wu Wenwen
- Department of Translational Oncology, St. Marianna University Graduate School of Medicine, Kawasaki, Japan
| | - Tomohiko Ohta
- Department of Translational Oncology, St. Marianna University Graduate School of Medicine, Kawasaki, Japan
| | - Shin-Ichi Hayashi
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, 2-1 Seoryo-machi, Aoba-ku, Sendai, 980-8575, Japan.
| |
Collapse
|
3
|
Xiang P, Wang K, Bi J, Li M, He RW, Cui D, Ma LQ. Organic extract of indoor dust induces estrogen-like effects in human breast cancer cells. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 726:138505. [PMID: 32481214 DOI: 10.1016/j.scitotenv.2020.138505] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 04/02/2020] [Accepted: 04/04/2020] [Indexed: 06/11/2023]
Abstract
Indoor dust often contains organic contaminants, which adversely impacts human health. In this study, the organic contaminants in the indoor dust from commercial offices and residential houses in Nanjing, China were extracted and their effects on human breast cancer cells (MCF-7) were investigated. Both dust extracts promoted proliferation of MCF-7 cells at ≤24 μg/100 μL, with cell viability being decreased with increasing dust concentrations. Based on LC50, house dust was less toxic than office dust. At 8 μg/100 μL, both extracts caused more MCF-7 cells into active cycling (G2/M + S) and increased intracellular Ca2+ influx, with house dust inducing stronger effects than office dust. Further, the expression of estrogen-responsive genes for TFF1 and EGR3 was enhanced by 3-9 and 4-9 folds, while the expression of cell cycle regulatory genes for cyclin D was enhanced by 2-5 folds. The results suggested that organic dust extract influenced cell viability, altered cell cycle, increased intracellular Ca2+ levels, and activated cell cycle regulatory and estrogen-responsive gene expressions, with house dust showing lower cytotoxicity but higher estrogenic potential on MCF-7 cells. The results indicate the importance of reducing organic contaminants in indoor dust to mitigate their adverse impacts on human health.
Collapse
Affiliation(s)
- Ping Xiang
- Yunnan Key Laboratory of Ecological Environment Evolution and Pollution Control in Mountainous Rural Areas, Institute of Environmental Remediation and Human Health, Southwest Forestry University, Kunming 650224, China; Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Kun Wang
- Yunnan Key Laboratory of Ecological Environment Evolution and Pollution Control in Mountainous Rural Areas, Institute of Environmental Remediation and Human Health, Southwest Forestry University, Kunming 650224, China
| | - Jue Bi
- Yunnan Key Laboratory of Ecological Environment Evolution and Pollution Control in Mountainous Rural Areas, Institute of Environmental Remediation and Human Health, Southwest Forestry University, Kunming 650224, China
| | - Mengying Li
- Yunnan Key Laboratory of Ecological Environment Evolution and Pollution Control in Mountainous Rural Areas, Institute of Environmental Remediation and Human Health, Southwest Forestry University, Kunming 650224, China
| | - Rui-Wen He
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, China
| | - Daolei Cui
- Yunnan Key Laboratory of Ecological Environment Evolution and Pollution Control in Mountainous Rural Areas, Institute of Environmental Remediation and Human Health, Southwest Forestry University, Kunming 650224, China.
| | - Lena Q Ma
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
| |
Collapse
|
4
|
Niwa T, Takanobu J, Suzuki K, Sato Y, Yamaguchi Y, Hayashi SI. Characterization of a membrane-associated estrogen receptor in breast cancer cells and its contribution to hormone therapy resistance using a novel selective ligand. J Steroid Biochem Mol Biol 2020; 201:105671. [PMID: 32289430 DOI: 10.1016/j.jsbmb.2020.105671] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 03/23/2020] [Accepted: 04/03/2020] [Indexed: 11/24/2022]
Abstract
The estrogen receptor (ER) plays a role in the progression of hormone-dependent breast cancer and is a hormone therapy target. Estrogen acts as a transcription factor (genomic action) and also produces a quick non-genomic reaction through intracellular signaling pathways. The membrane associated ER (mER) may regulate both these signals and hormone therapy resistance. However, the details remain unclear because a reliable method to distinguish the signals induced by the estradiol (E2)-mER and E2-nuclear ER complex has not been established. In the present study, we prepared the novel ligand Qdot-6-E2, selective for mER, by coupling E2 with insoluble quantum dot nano-beads. We investigated the characteristics of mER signaling pathways and its contribution to hormone therapy resistance using different cell lines including estrogen depletion resistant (EDR) cells with different mechanisms. Qdot-6-E2 stimulated proliferation of nuclear ER-positive cells, but nuclear ER-negative cells showed no response. In addition, Qdot-6-E2 indirectly activated nuclear ER and increased mRNA expression of target genes. We confirmed that E2 was not dissociated from Qdot-6-E2 using a mammalian one-hybrid assay. We visually demonstrated that Qdot-6-E2 acts from the outside of cells. The gene expression profile induced by Qdot-6-E2-mER was different from that induced by E2-nuclear ER. The effect of anti-ER antibody, the GFP-ER fusion protein localization, and the effect of palmitoyl acyltransferase inhibitor also indicated the existence of mER. Regarding intracellular phosphorylation signaling pathways, the MAPK (Erk 1/2) and the PI3K/Akt pathways were both activated by Qdot-6-E2. In EDR cells, only nuclear ER-positive cells showed increased cell proliferation with increased localization of ERα to the membrane fraction. These findings suggested that Qdot-6-E2 reacts with ERα surrounding the cell membrane and that mER signals help the cells to survive under estrogen-depleted conditions by re-localizing the ER to use trace amounts of E2 more effectively. We expect that Qdot-6-E2 is a useful tool for studying the mER.
Collapse
Affiliation(s)
- Toshifumi Niwa
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
| | - Junko Takanobu
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Kanae Suzuki
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Yuta Sato
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Yuri Yamaguchi
- Research Institute for Clinical Oncology, Saitama Cancer Center, Saitama, Japan
| | - Shin-Ichi Hayashi
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| |
Collapse
|
5
|
Iida M, Toyosawa D, Nakamura M, Tsuboi K, Tokuda E, Niwa T, Ishida T, Hayashi SI. Decreased ER dependency after acquired resistance to CDK4/6 inhibitors. Breast Cancer 2020; 27:963-972. [PMID: 32297248 DOI: 10.1007/s12282-020-01090-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 04/08/2020] [Indexed: 11/26/2022]
Abstract
BACKGROUND Cyclin-dependent kinase (CDK) 4/6 inhibitors represent a significant advancement in the treatment of estrogen receptor (ER)-positive human epidermal growth factor receptor 2-negative advanced breast cancer. However, mechanisms of alterations after acquired resistance to CDK4/6 inhibitors and the optimal treatment options are still not established. METHODS Abemaciclib-resistant cell lines were established from the models of estrogen deprivation-resistant cell lines which retained ER expression and activated ER function derived from MCF-7 breast cancer cell lines. Ribocilib-resistant cell lines were established in the same method as previously reported. RESULTS Both abemaciclib- and ribociclib-resistant cell lines showed decreased ER expression. ER transcriptional activity was maintained in these cell lines; however, the sensitivity to 4-hydroxytamoxifen and fulvestrant was almost completely lost. These cell lines did not exhibit any ERα gene mutation. Abemaciclib-resistant cell lines demonstrated low sensitivity to other CDK4/6 inhibitors; sensitivities to PI3K inhibitor, mTOR inhibitor, and chemotherapeutic drugs were maintained. CONCLUSIONS Dependence on ER signaling appears to decrease after the development of acquired resistance to CDK4/6 inhibitors. Further, CDK4/6 inhibitor-resistant cells acquired cross-resistance to other CDK4/6 inhibitors, PI3K/Akt/mTOR inhibitor therapy and chemotherapeutic drugs might serve as optimal treatment options for such breast cancers.
Collapse
Affiliation(s)
- Masafumi Iida
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, 2-1, Seiryoumachi, Aoba-ku, Sendai, 980-8575, Japan.
- Department of Breast and Endocrine Surgical Oncology, Graduate School of Medicine, Tohoku University, Sendai, Japan.
| | - Daichi Toyosawa
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, 2-1, Seiryoumachi, Aoba-ku, Sendai, 980-8575, Japan
| | - Misato Nakamura
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, 2-1, Seiryoumachi, Aoba-ku, Sendai, 980-8575, Japan
| | - Kouki Tsuboi
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, 2-1, Seiryoumachi, Aoba-ku, Sendai, 980-8575, Japan
| | - Emi Tokuda
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, 2-1, Seiryoumachi, Aoba-ku, Sendai, 980-8575, Japan
| | - Toshifumi Niwa
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, 2-1, Seiryoumachi, Aoba-ku, Sendai, 980-8575, Japan
| | - Takanori Ishida
- Department of Breast and Endocrine Surgical Oncology, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Shin-Ichi Hayashi
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, 2-1, Seiryoumachi, Aoba-ku, Sendai, 980-8575, Japan
| |
Collapse
|
6
|
Iida M, Nakamura M, Tokuda E, Toyosawa D, Niwa T, Ohuchi N, Ishida T, Hayashi SI. The p21 levels have the potential to be a monitoring marker for ribociclib in breast cancer. Oncotarget 2019; 10:4907-4918. [PMID: 31448056 PMCID: PMC6690670 DOI: 10.18632/oncotarget.27127] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 07/21/2019] [Indexed: 11/25/2022] Open
Abstract
Although cyclin-dependent kinase (CDK) 4/6 inhibitors have exhibited remarkable results for patients with estrogen receptor (ER)–positive breast cancer in clinical trials, the mechanism of CDK4/6 inhibitor resistance remains unclear. Thus, this study aimed to investigate the mechanism of CDK4/6 inhibitor resistance using two CDK4/6 inhibitor resistant breast cancer cell lines. We established CDK6 overexpressed cell lines (MCF7-C6) from MCF-7 cells using the stably transfected CDK6 expression vector. Additionally, acquired ribociclib-resistant (RIBR) cell lines were created using ER-positive hormone-resistant cell lines by long-term exposure to ribociclib. CDK6 overexpression and the knockdown of CDK4 experiments highlight the significance of high levels of CDK4 and low levels of CDK6 in CDK4/6 inhibitor sensitivity. Moreover, RIBR cell lines did not exhibit incremental CDK6 compared with ER-positive hormone-resistant cell lines. In MCF7-C6 and RIBR cell lines, p21 levels decreased, and p21 levels were proportional to CDK4/6 inhibitor sensitivity. This study suggests that overexpression of CDK6 is one of the many possible mechanisms of resistance to CDK4/6 inhibitors. Furthermore, p21 levels have the potential to serve as a marker for CDK4/6 inhibitors independent of the resistance mechanism.
Collapse
Affiliation(s)
- Masafumi Iida
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Sendai, Japan.,Department of Breast and Endocrine Surgical Oncology, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Misato Nakamura
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Emi Tokuda
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Daichi Toyosawa
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Toshifumi Niwa
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Noriaki Ohuchi
- Department of Breast and Endocrine Surgical Oncology, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Takanori Ishida
- Department of Breast and Endocrine Surgical Oncology, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Shin-Ichi Hayashi
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Sendai, Japan
| |
Collapse
|
7
|
Tumor microenvironmental growth factors induce long-term estrogen deprivation resistance in breast cancer. Breast Cancer 2019; 26:748-757. [PMID: 31119683 DOI: 10.1007/s12282-019-00978-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 05/17/2019] [Indexed: 10/26/2022]
Abstract
BACKGROUND Hormonal therapy is an effective treatment for luminal-like breast cancer. Aromatase inhibitor (AI) is widely used for estrogen receptor-positive, postmenopausal breast cancers. However, resistance is occurred and becomes a serious clinical concern. In general, progression of cancer strongly depends on tumor microenvironment, which may, therefore, also contribute to the development of AI resistance. METHODS We evaluated tumor microenvironment-derived factors with respect to AI resistance using typical estrogen receptor-positive breast cancer cell lines. We established tumor microenvironment-dependent AI-resistant models and elucidated the underlying mechanisms. RESULTS T-47D cells had a higher dependence on microenvironment-derived factors, such as estrogen or growth factors, for survival than MCF-7 cells. We, therefore, evaluated tumor microenvironment growth factors with respect to AI resistance using T-47D cells. We established three resistant cell lines (V1, V2, and V3) that survived estrogen deprivation and growth factor-supplemented conditions. These cell lines were deficient in estrogen receptor α expression and estrogen-dependent growth. Among six representative growth factors, epidermal growth factor was the most influential. In these models, HER2 protein was overexpressed without gene amplification and intracellular phosphorylation pathways were activated compared to parental cell lines. Molecular targeting inhibitors revealed that V1 and V2 primarily rely on the PI3 K pathway for survival, whereas V3 relies on the MAPK pathway. CONCLUSIONS This study demonstrates the importance of tumor microenvironment-derived factors for the development of AI resistance. These resistant models did not utilize the same resistance mechanism, suggesting that flexible strategies are essential in conquering resistance.
Collapse
|
8
|
Cancer stem-like properties of hormonal therapy-resistant breast cancer cells. Breast Cancer 2019; 26:459-470. [DOI: 10.1007/s12282-018-00944-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 12/20/2018] [Indexed: 01/03/2023]
|
9
|
Compensatory role of insulin-like growth factor 1 receptor in estrogen receptor signaling pathway and possible therapeutic target for hormone therapy-resistant breast cancer. Breast Cancer 2018; 26:272-281. [PMID: 30328006 DOI: 10.1007/s12282-018-0922-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 10/03/2018] [Indexed: 01/04/2023]
Abstract
BACKGROUND Hormone therapy targeting the estrogen receptor (ER) pathway is the most common treatment used for ER-positive breast cancer. However, some patients experience de novo or acquired resistance, which becomes a critical problem. Activation of the insulin-like growth factor (IGF) pathway allows breast cancer cells to proliferate and is associated with the ER pathway. Little is known about the role of the IGF pathway in hormone therapy and resistance; therefore, we investigated whether the inhibition of this pathway may represent a novel therapeutic target for overcoming hormone therapy resistance in ER-positive breast cancers. METHODS Crosstalk between the ER and IGF pathways was analyzed in breast cancer cell lines by inhibiting or stimulating either one or both pathways. We studied the effect of insulin-like growth factor one receptor (IGF1R) inhibition in aromatase inhibitor-resistant breast cancer cell lines and fulvestrant-resistant cell lines which were uniquely established in our laboratory. RESULTS Under normal conditions, IGF signaling is controlled by ER signaling to promote cell growth. Temporary disruption of the estrogen supply results in attenuated ER signaling, and IGF-1 dramatically increased relative growth compared with normal conditions. In addition, IGF1R inhibitor strongly suppressd cell growth in hormone-resistant breast cancer cells where ER remains than cells where ER decreased or was almost lost. CONCLUSIONS Our study suggests that inhibition of the IGF pathway may be an effective strategy for ER-positive breast cancer therapy, even in hormone therapy-resistant cases.
Collapse
|
10
|
Hayashi T, Hikichi M, Yukitake J, Wakatsuki T, Nishio E, Utsumi T, Harada N. Forskolin increases the effect of everolimus on aromatase inhibitor-resistant breast cancer cells. Oncotarget 2018; 9:23451-23461. [PMID: 29805747 PMCID: PMC5955115 DOI: 10.18632/oncotarget.25217] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 04/06/2018] [Indexed: 01/31/2023] Open
Abstract
Aromatase inhibitor (AI) resistance is a major obstacle in the treatment of estrogen receptor-positive breast cancer. Everolimus (EVE) ameliorates AI-resistant breast cancer and is therefore used in cancer treatment. However, some patients show resistance to EVE. Here, we used 30 clones of long-term estrogen-deprived (LTED) MCF-7 cells as a model of AI-resistant breast cancer. We examined changes in protein phosphatase type 2A (PP2A) and cancerous inhibitor of PP2A (CIP2A), a negative regulator of PP2A, in LTED cells treated with EVE. In LTED cells with high sensitivity to EVE, CIP2A expression decreased at low EVE concentrations; however, in LTED cells poorly sensitive to EVE, CIP2A and PP2A did not change upon exposure to EVE. Therefore, we hypothesized that there is a relation between expression of CIP2A and sensitivity to EVE. Knockdown of CIP2A increased the sensitivity to EVE in three clones poorly sensitive to EVE. Additionally, we found that treatment with FSK, which activates PP2A, increased the sensitivity of the cells to EVE. Our data point to CIP2A and PP2A as novel therapeutic targets for AI-resistant breast cancer.
Collapse
Affiliation(s)
- Takanori Hayashi
- Department of Biochemistry, School of Medicine, Fujita Health University, Aichi, Japan
| | - Masahiro Hikichi
- Department of Breast Surgery, School of Medicine, Fujita Health University, Aichi, Japan
| | - Jun Yukitake
- Department of Clinical Immunology, School of Health Sciences, Fujita Health University, Aichi, Japan
| | - Toru Wakatsuki
- Department of Health Science, School of Medicine, Fujita Health University, Aichi, Japan
| | - Eiji Nishio
- Department of Obstetrics and Gynecology, School of Medicine, Fujita Health University, Aichi, Japan
| | - Toshiaki Utsumi
- Department of Breast Surgery, School of Medicine, Fujita Health University, Aichi, Japan
| | - Nobuhiro Harada
- Department of Biochemistry, School of Medicine, Fujita Health University, Aichi, Japan
| |
Collapse
|
11
|
Kimura M, Hanamura T, Tsuboi K, Kaneko Y, Yamaguchi Y, Niwa T, Narui K, Endo I, Hayashi SI. Acquired resistance to everolimus in aromatase inhibitor-resistant breast cancer. Oncotarget 2018; 9:21468-21477. [PMID: 29765553 PMCID: PMC5940386 DOI: 10.18632/oncotarget.25133] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 03/23/2018] [Indexed: 12/03/2022] Open
Abstract
We previously reported the establishment of several types of long-term estrogen-depleted-resistant (EDR) cell lines from MCF-7 breast cancer cells. Type 1 EDR cells exhibited the best-studied mechanism of aromatase inhibitor (AI) resistance, in which estrogen receptor (ER) expression remained positive and PI3K signaling was upregulated. Type 2 EDR cells showed reduced ER activity and upregulated JNK-related signaling. The mTOR inhibitor everolimus reduced growth in cells similar to Type 1 EDR cells. The present study generated everolimus-resistant (EvR) cells from Types 1 and 2 EDR cells following long-term exposure to everolimus in vitro. These EvR cells modeled resistance to AI and everolimus combination therapies following first-line AI treatment failure. In Type 1 EvR cells, everolimus resistance was dependent on MAPK signaling; single agents were not effective, but hormonal therapy combined with a kinase inhibitor effectively reduced cell growth. In Type 2 EvR cells, ER expression remained negative and a JNK inhibitor was ineffective, but a Src inhibitor reduced cell growth. The mechanism of acquired everolimus resistance appears to vary depending on the mechanism of AI resistance. Strategies targeting resistant tumors should be tailored based on the resistance mechanisms, as these mechanisms impact therapeutic efficacy.
Collapse
Affiliation(s)
- Mariko Kimura
- Department of Molecular and Functional Dynamics, Tohoku University Graduate School of Medicine, Sendai, Japan.,Department of Gastroenterological Surgery and Clinical Oncology, Yokohama City University Graduate School of Medicine, Yokohama, Japan.,Department of Breast and Thyroid Surgery, Yokohama City University Medical Center, Yokohama, Japan
| | - Toru Hanamura
- Department of Molecular and Functional Dynamics, Tohoku University Graduate School of Medicine, Sendai, Japan.,Division of Breast and Endocrine Surgery, Department of Surgery, Shinshu University School of Medicine, Nagano, Japan
| | - Kouki Tsuboi
- Department of Molecular and Functional Dynamics, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Yosuke Kaneko
- Department of Molecular and Functional Dynamics, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Yuri Yamaguchi
- Research Institute for Clinical Oncology, Saitama Cancer Center, Ina-machi, Japan
| | - Toshifumi Niwa
- Department of Molecular and Functional Dynamics, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Kazutaka Narui
- Department of Breast and Thyroid Surgery, Yokohama City University Medical Center, Yokohama, Japan
| | - Itaru Endo
- Department of Gastroenterological Surgery and Clinical Oncology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Shin-Ichi Hayashi
- Department of Molecular and Functional Dynamics, Tohoku University Graduate School of Medicine, Sendai, Japan
| |
Collapse
|
12
|
Zeng X, Che X, Liu YP, Qu XJ, Xu L, Zhao CY, Zheng CL, Hou KZ, Teng Y. FEN1 knockdown improves trastuzumab sensitivity in human epidermal growth factor 2-positive breast cancer cells. Exp Ther Med 2017; 14:3265-3272. [PMID: 28912877 DOI: 10.3892/etm.2017.4873] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 04/28/2017] [Indexed: 12/18/2022] Open
Abstract
Trastuzumab has been widely applied as a treatment for human epidermal growth factor 2 (HER2)-overexpressing breast cancer. However, the therapeutic efficacy of trastuzumab is limited. Flap endonuclease 1 (FEN1) is a multifunctional endonuclease that has a crucial role in DNA recombination and repair. Inhibition of FEN1 is associated with the reversal of anticancer drug resistance. However, it is unclear whether FEN1 is involved in trastuzumab resistance. In the present study, it was demonstrated that trastuzumab increases the expression of FEN1, and FEN1 knockdown significantly enhanced the sensitivity of BT474 cells to trastuzumab (P<0.05). It was also revealed that trastuzumab induced HER receptor activation, increased binding with FEN1 and estrogen receptor α (ERα), and upregulated ERα-target gene transcription (P<0.05). Upon silencing of FEN1 expression with siRNA, activation of HER receptor and FEN1 binding to ERα were decreased, and trastuzumab-induced ERα target gene upregulation was partially ameliorated (P<0.05). These results suggest that FEN1 may mediate trastuzumab resistance via inducing HER receptor activation and enhancing ERα-target gene transcription. The findings of the present study indicate a novel role of FEN1 in trastuzumab resistance, suggesting that targeting FEN1 may enhance the efficiency of trastuzumab as a treatment for HER2-positive breast cancer.
Collapse
Affiliation(s)
- Xue Zeng
- Department of Medical Oncology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Xiaofang Che
- Department of Medical Oncology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Yun-Peng Liu
- Department of Medical Oncology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Xiu-Juan Qu
- Department of Medical Oncology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Lu Xu
- Department of Medical Oncology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Chen-Yang Zhao
- Central Laboratory, The Fourth Hospital of China Medical University, Shenyang, Liaoning 110032, P.R. China
| | - Chun-Lei Zheng
- Department of Medical Oncology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Ke-Zuo Hou
- Department of Medical Oncology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Yuee Teng
- Department of Medical Oncology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| |
Collapse
|
13
|
Tsuboi K, Nagatomo T, Gohno T, Higuchi T, Sasaki S, Fujiki N, Kurosumi M, Takei H, Yamaguchi Y, Niwa T, Hayashi SI. Single CpG site methylation controls estrogen receptor gene transcription and correlates with hormone therapy resistance. J Steroid Biochem Mol Biol 2017; 171:209-217. [PMID: 28412323 DOI: 10.1016/j.jsbmb.2017.04.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Revised: 03/14/2017] [Accepted: 04/06/2017] [Indexed: 12/19/2022]
Abstract
Hormone therapy is the most effective treatment for patients with estrogen receptor α-positive breast cancers. However, although resistance occurs during treatment in some cases and often reflects changed estrogen receptor α status, the relationship between changes in estrogen receptor α expression and resistance to therapy are poorly understood. In this study, we identified a mechanism for altered estrogen receptor α expression during disease progression and acquired hormone therapy resistance in aromatase inhibitor-resistant breast cancer cell lines. Subsequently, we investigated promoter switching and DNA methylation status of the estrogen receptor α promoter, and found marked changes of methylation at a single CpG site (CpG4) in resistant cells. In addition, luciferase reporter assays showed reduced transcriptional activity from this methylated CpG site. This CpG region was also completely conserved among species, suggesting that it acts as a methylation-sensitive Ets-2 transcription factor binding site, as confirmed using chromatin immunoprecipitation assays. In estrogen receptor α-positive tumors, CpG4 methylation levels were inversely correlated with estrogen receptor α expression status, suggesting that single CpG site plays an important role in the regulation of estrogen receptor α transcription.
Collapse
Affiliation(s)
- Kouki Tsuboi
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, 980-8575, Japan
| | - Takamasa Nagatomo
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, 980-8575, Japan
| | - Tatsuyuki Gohno
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, 980-8575, Japan
| | - Toru Higuchi
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, 980-8575, Japan
| | - Shunta Sasaki
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, 980-8575, Japan
| | - Natsu Fujiki
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, 980-8575, Japan
| | - Masafumi Kurosumi
- Department of Pathology, Saitama Cancer Center, Ina-machi, Saitama, 362-0806, Japan
| | - Hiroyuki Takei
- Division of Breast Surgery, Saitama Cancer Center, Ina-machi, Saitama, 362-0806, Japan
| | - Yuri Yamaguchi
- Resarch Institute for Clinical Oncology, Saitama Cancer Center, Ina-machi, Saitama, 362-0806, Japan
| | - Toshifumi Niwa
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, 980-8575, Japan
| | - Shin-Ichi Hayashi
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, 980-8575, Japan; Center for Regulatory Epigenome and Diseases, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, 980-8575, Japan.
| |
Collapse
|
14
|
Overcoming aromatase inhibitor resistance in breast cancer: possible mechanisms and clinical applications. Breast Cancer 2017; 25:379-391. [PMID: 28389808 DOI: 10.1007/s12282-017-0772-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 03/28/2017] [Indexed: 10/19/2022]
Abstract
Estrogen plays crucial roles in the progression of hormone-dependent breast cancers through activation of nuclear estrogen receptor α (ER). Estrogen is produced locally from circulating inactive steroids and adrenal androgens in postmenopausal women. However, conversion by aromatase is a rate-limiting step in intratumoral estrogen production in breast cancer. Aromatase inhibitors (AIs) inhibit the growth of hormone-dependent breast cancers by blocking the conversion of adrenal androgens to estrogen and by unmasking the inhibitory effect of androgens, acting via the androgen receptor (AR). AIs are thus a standard treatment option for postmenopausal hormone-dependent breast cancer. However, although initial use of AIs provides substantial clinical benefit, some breast cancer patients relapse because of the acquisition of AI resistance. A better understanding of the mechanisms of AI resistance may contribute to the development of new therapeutic strategies and aid in the search for new therapeutic targets and agents. We have investigated AI-resistance mechanisms and established six AI-resistant cell lines. Some of them exhibit estrogen depletion-resistance properties via constitutive ER-activation or ER-independent growth signaling. We examined how breast cancer cells can adapt to estrogen depletion and androgen superabundance. Estrogen and estrogenic androgen produced independently from aromatase contributed to cell proliferation in some of these cell lines, while another showed AR-dependent cell proliferation. Based on these findings, currently proposed AI-resistance mechanisms include an aromatase-independent estrogen-producing pathway, estrogen-independent ER function, and ER-independent growth signaling. This review summarizes several hypotheses of AI-resistance mechanisms and discusses how existing or novel therapeutic agents may be applied to treat AI-resistant breast cancers.
Collapse
|
15
|
Tsuboi K, Kaneko Y, Nagatomo T, Fujii R, Hanamura T, Gohno T, Yamaguchi Y, Niwa T, Hayashi SI. Different epigenetic mechanisms of ERα implicated in the fate of fulvestrant-resistant breast cancer. J Steroid Biochem Mol Biol 2017; 167:115-125. [PMID: 27888136 DOI: 10.1016/j.jsbmb.2016.11.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 11/04/2016] [Accepted: 11/21/2016] [Indexed: 11/25/2022]
Abstract
Approximately 70% of breast cancers express estrogen receptor α (ERα), which plays critical roles in breast cancer development. Fulvestrant has been effectively used to treat ERα-positive breast cancer, although resistance remains a critical problem. To elucidate the mechanism of resistance to fulvestrant, we established fulvestrant-resistant cell-lines named MFR (MCF-7 derived fulvestrant resistance) and TFR (T-47D derived fulvestrant resistance) from the ERα-positive luminal breast cancer cell lines MCF-7 and T-47D, respectively. Both fulvestrant-resistant cell lines lost sensitivity to estrogen and anti-estrogens. We observed diminished ERα expression at both the protein and mRNA levels. To address the mechanism of gene expression regulation, we examined epigenetic alteration, especially the DNA methylation level of ERα gene promoters. MFR cells displayed high methylation levels upstream of the ERα gene, whereas no change in DNA methylation was observed in TFR cells. Hence, we examined the gene expression plasticity of ERα, as there are differences in its reversibility following fulvestrant withdrawal. ERα gene expression was not restored in MFR cells, and alternative intracellular phosphorylation signals were activated. By contrast, TFR cells exhibited plasticity of ERα gene expression and ERα-dependent growth; moreover, these cells were resensitized to estrogen and anti-estrogens. The difference in epigenetic regulation among individual cells might explain the difference in the plasticity of ERα expression. We also identified an MFR cell-activating HER/Src-Akt/MAPK pathway; thus, the specific inhibitors effectively blocked MFR cell growth. This finding implies the presence of multiple fulvestrant resistance mechanisms and suggests that the optimal therapies differ among individual tumors as a result of differing epigenetic mechanisms regulating ERα gene expression.
Collapse
Affiliation(s)
- Kouki Tsuboi
- Department of Molecular and Functional Dynamics, Graduate Tohoku University School of Medicine, Sendai, Japan
| | - Yosuke Kaneko
- Department of Molecular and Functional Dynamics, Graduate Tohoku University School of Medicine, Sendai, Japan
| | - Takamasa Nagatomo
- Department of Molecular and Functional Dynamics, Graduate Tohoku University School of Medicine, Sendai, Japan
| | - Rika Fujii
- Department of Molecular and Functional Dynamics, Graduate Tohoku University School of Medicine, Sendai, Japan; Surgical Oncology, Graduate Tohoku University School of Medicine, Sendai, Japan
| | - Toru Hanamura
- Department of Molecular and Functional Dynamics, Graduate Tohoku University School of Medicine, Sendai, Japan; Division of Breast and Endocrine Surgery, Department of Surgery, Shinshu University School of Medicine, Nagano, Japan
| | - Tatsuyuki Gohno
- Department of Molecular and Functional Dynamics, Graduate Tohoku University School of Medicine, Sendai, Japan
| | - Yuri Yamaguchi
- Research Institute for Clinical Oncology, Saitama Cancer Center, Saitama, Japan
| | - Toshifumi Niwa
- Department of Molecular and Functional Dynamics, Graduate Tohoku University School of Medicine, Sendai, Japan
| | - Shin-Ichi Hayashi
- Department of Molecular and Functional Dynamics, Graduate Tohoku University School of Medicine, Sendai, Japan; Center for Regulatory Epigenome and Diseases, Graduate Tohoku University School of Medicine, Sendai, Japan.
| |
Collapse
|
16
|
Niwa T, Shinagawa Y, Asari Y, Suzuki K, Takanobu J, Gohno T, Yamaguchi Y, Hayashi SI. Estrogen receptor activation by tobacco smoke condensate in hormonal therapy-resistant breast cancer cells. J Steroid Biochem Mol Biol 2017; 165:448-457. [PMID: 27632897 DOI: 10.1016/j.jsbmb.2016.09.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 09/06/2016] [Accepted: 09/11/2016] [Indexed: 12/23/2022]
Abstract
The relationship between tobacco smoke and breast cancer incidence has been studied for many years, but the effect of smoking on hormonal therapy has not been previously reported. We investigated the effect of smoking on hormonal therapy by performing in vitro experiments. We first prepared tobacco smoke condensate (TSC) and examined its effect on estrogen receptor (ER) activity. The ER activity was analyzed using MCF-7-E10 cells into which the estrogen-responsive element (ERE)-green fluorescent protein (GFP) reporter gene had been stably introduced (GFP assay) and performing an ERE-luciferase assay. TSC significantly activated ERs, and upregulated its endogenous target genes. This activation was inhibited by fulvestrant but more weakly by tamoxifen. These results suggest that the activation mechanism may be different from that for estrogen. Furthermore, using E10 estrogen depletion-resistant cells (EDR cells) established as a hormonal therapy-resistant model showing estrogen-independent ER activity, ER activation and induction of ER target genes were significantly higher following TSC treatment than by estradiol (E2). These responses were much higher than those of the parental E10 cells. In addition, the phosphorylation status of signaling factors (ERK1/2, Akt) and ER in the E10-EDR cells treated with TSC increased. The gene expression profile induced by estrogenic effects of TSC was characterized by microarray analysis. The findings suggested that TSC activates ER by both ligand-dependent and -independent mechanisms. Although TSC constituents will be metabolized in vivo, breast cancer tissues might be exposed for a long period along with hormonal therapy. Tobacco smoke may have a possibility to interfere with hormonal therapy for breast cancer, which may have important implications for the management of therapy.
Collapse
Affiliation(s)
- Toshifumi Niwa
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
| | - Yuri Shinagawa
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Yosuke Asari
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Kanae Suzuki
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Junko Takanobu
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Tatsuyuki Gohno
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Yuri Yamaguchi
- Research Institute for Clinical Oncology, Saitama Cancer Center, Saitama, Japan
| | - Shin-Ichi Hayashi
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Aoba-ku, Sendai, Miyagi, 980-8575, Japan; Center for Regulatory Epigenome and Diseases, Graduate School of Medicine, Tohoku University, Sendai, Japan
| |
Collapse
|
17
|
Higuchi T, Endo M, Hanamura T, Gohno T, Niwa T, Yamaguchi Y, Horiguchi J, Hayashi SI. Contribution of Estrone Sulfate to Cell Proliferation in Aromatase Inhibitor (AI) -Resistant, Hormone Receptor-Positive Breast Cancer. PLoS One 2016; 11:e0155844. [PMID: 27228187 PMCID: PMC4882040 DOI: 10.1371/journal.pone.0155844] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2016] [Accepted: 05/05/2016] [Indexed: 12/22/2022] Open
Abstract
Aromatase inhibitors (AIs) effectively treat hormone receptor-positive postmenopausal breast cancer, but some patients do not respond to treatment or experience recurrence. Mechanisms of AI resistance include ligand-independent activation of the estrogen receptor (ER) and signaling via other growth factor receptors; however, these do not account for all forms of resistance. Here we present an alternative mechanism of AI resistance. We ectopically expressed aromatase in MCF-7 cells expressing green fluorescent protein as an index of ER activity. Aromatase-overexpressing MCF-7 cells were cultured in estrogen-depleted medium supplemented with testosterone and the AI, letrozole, to establish letrozole-resistant (LR) cell lines. Compared with parental cells, LR cells had higher mRNA levels of steroid sulfatase (STS), which converts estrone sulfate (E1S) to estrone, and the organic anion transporter peptides (OATPs), which mediate the uptake of E1S into cells. LR cells proliferated more in E1S-supplemented medium than did parental cells, and LR proliferation was effectively inhibited by an STS inhibitor in combination with letrozole and by ER-targeting drugs. Analysis of ER-positive primary breast cancer tissues showed a significant correlation between the increases in the mRNA levels of STS and the OATPs in the LR cell lines, which supports the validity of this AI-resistant model. This is the first study to demonstrate the contribution of STS and OATPs in E1S metabolism to the proliferation of AI-resistant breast cancer cells. We suggest that E1S metabolism represents a new target in AI-resistant breast cancer treatment.
Collapse
Affiliation(s)
- Toru Higuchi
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan
- Department of Visceral and Thoracic Organ Surgery, Graduated School of Medicine, Gunma University, Maebashi, Gunma, Japan
| | - Megumi Endo
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan
| | - Toru Hanamura
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan
- Division of Breast and Endocrine Surgery, Department of Surgery, Shinshu University School of Medicine, Matsumoto, Nagano, Japan
| | - Tatsuyuki Gohno
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan
| | - Toshifumi Niwa
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan
| | - Yuri Yamaguchi
- Research Institute for Clinical Oncology, Saitama Cancer Center, Ina, Saitama, Japan
| | - Jun Horiguchi
- Department of Visceral and Thoracic Organ Surgery, Graduated School of Medicine, Gunma University, Maebashi, Gunma, Japan
| | - Shin-ichi Hayashi
- Department of Molecular and Functional Dynamics, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan
- Center for Regulatory Epi genome and Diseases, Graduate School of Medicine, Tohoku University, Sendai, Niyagi, Japan
| |
Collapse
|
18
|
Hamada T, Souda M, Yoshimura T, Sasaguri S, Hatanaka K, Tasaki T, Yoshioka T, Ohi Y, Yamada S, Tsutsui M, Umekita Y, Tanimoto A. Anti-apoptotic effects of PCP4/PEP19 in human breast cancer cell lines: a novel oncotarget. Oncotarget 2015; 5:6076-86. [PMID: 25153723 PMCID: PMC4171614 DOI: 10.18632/oncotarget.2161] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The PCP4/PEP19 is a calmodulin-binding anti-apoptotic peptide in neural cells but its potential role in human cancer has largely been unknown. We investigated the expression of PCP4/PEP19 in human breast cancer cell lines MCF-7, SK-BR-3, and MDA-MB-231 cells, and found that estrogen receptor (ER)-positive MCF-7 and ER-negative SK-BR-3 cells expressed PCP4/PEP19. In the MCF-7 cells, cell proliferation was estrogen-dependent, and PCP4/PEP19 expression was induced by estrogen. In both cell lines, PCP4/PEP19 knockdown induced apoptosis and slightly decreased Akt phosphorylation. Knockdown of calcium/calmodulin-dependent protein kinase kinase 1 (CaMKK1), resulting in decreased phospho-AktThr308, enhanced apoptosis in SK-BR-3 but not in MCF-7 cells. CaMKK2 knockdown moderately decreased phospho-AktThr308 and increased apoptosis in MCF-7 cells but not in SK-BR-3 cells. These data indicated that PCP4/PEP19 regulates apoptosis but exact mechanism is still unknown. PCP4/PEP19 can therefore potentially serve as independent oncotarget for therapy of PCP4/PEP19-positive breast cancers irrespective of ER expression.
Collapse
Affiliation(s)
- Taiji Hamada
- Department of Molecular and Cellular Pathology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Masakazu Souda
- Department of Molecular and Cellular Pathology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Takuya Yoshimura
- Department of Oral and Maxillofacial Surgery, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Shoko Sasaguri
- Department of Molecular and Cellular Pathology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Kazuhito Hatanaka
- Department of Molecular and Cellular Pathology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Takashi Tasaki
- Department of Molecular and Cellular Pathology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Takako Yoshioka
- Department of Molecular and Cellular Pathology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Yasuyo Ohi
- Department of Pathology, Sagara Hospital, Social Medical Corporation Hakuaikai, Kagoshima, Japan
| | - Sohsuke Yamada
- Department of Pathology and Cell Biology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Masato Tsutsui
- Department of Pharmacology, Faculty of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Yoshihisa Umekita
- Division of Organ Pathology, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Akihide Tanimoto
- Department of Molecular and Cellular Pathology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| |
Collapse
|
19
|
Omoto Y, Takeshita T, Yamamoto Y, Yamamoto-Ibusuki M, Hayashi M, Sueta A, Fujiwara S, Taguchi T, Iwase H. Immunohistochemical analysis in ethinylestradiol-treated breast cancers after prior long-term estrogen-deprivation therapy. SPRINGERPLUS 2015; 4:108. [PMID: 25774336 PMCID: PMC4353819 DOI: 10.1186/s40064-015-0851-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 01/22/2015] [Indexed: 11/10/2022]
Abstract
BACKGROUND Estrogen receptor (ER) positive breast cancer can often be treated by hormone therapy; however a certain population of ER-positive patients become resistant to hormone therapy after long-term hormone treatment. Ethinylestradiol (EE2) is a derivative of estrogen, which has shown promising effects in these patients. METHODS We successfully obtained tissue samples from 6 patients undergoing EE2 treatment and examined 13 well-known breast cancer-related factors by immunohistochemistry. Of the 6 patients, 5 responded but one patient did not. RESULTS Before EE2 treatment, staining for both ER and androgen receptor (AR) was strong in the nucleus, and the progesterone receptor (PgR) was almost no staining. EE2 treatment significantly down-regulated ER and up-regulated PgR while nuclear and cytosolic AR were oppositely down- and up-regulated, respectively. Cytosolic staining of BRCA1 was significantly up-regulated by EE2 whereas nuclear staining tended to decrease. Individual comparisons suggested less induction of PgR and decreasing AKT but increasing pAKT in the non-responder following EE2 treatment. CONCLUSIONS Our observations revealed that EE2 activated ER downstream genes; however it did not stimulate cell growth. This suggests that hormone resistant cells might receive growth signals from a non-genomic pathway and this may be reflected in their sensitivity to EE2 treatment.
Collapse
Affiliation(s)
- Yoko Omoto
- Department of Breast and Endocrine Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto, 860-8556 Japan ; Department of Endocrinological and Breast Surgery, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Hirokoji Agaru, Kawaramachi-dori, Kamigyo-ku, Kyoto, 602-0841 Japan ; Department of Breast Surgery, Tanabe Central Hospital, 6-1-6, Tanabe-Chuo, Kyotanabe-city, Kyoto 610-0334 Japan
| | - Takashi Takeshita
- Department of Breast and Endocrine Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto, 860-8556 Japan
| | - Yutaka Yamamoto
- Department of Breast and Endocrine Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto, 860-8556 Japan
| | - Mutsuko Yamamoto-Ibusuki
- Department of Breast and Endocrine Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto, 860-8556 Japan
| | - Mitsuhiro Hayashi
- Department of Breast and Endocrine Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto, 860-8556 Japan
| | - Aiko Sueta
- Department of Breast and Endocrine Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto, 860-8556 Japan
| | - Saori Fujiwara
- Department of Breast and Endocrine Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto, 860-8556 Japan
| | - Tetsuya Taguchi
- Department of Endocrinological and Breast Surgery, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Hirokoji Agaru, Kawaramachi-dori, Kamigyo-ku, Kyoto, 602-0841 Japan
| | - Hirotaka Iwase
- Department of Breast and Endocrine Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto, 860-8556 Japan
| |
Collapse
|
20
|
Hayashi SI, Kimura M. Mechanisms of hormonal therapy resistance in breast cancer. Int J Clin Oncol 2015; 20:262-7. [PMID: 25652907 DOI: 10.1007/s10147-015-0788-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 01/19/2015] [Indexed: 02/07/2023]
Abstract
Whilst estrogen receptor (ER)-positive breast cancers are preferentially treated with hormone therapy, approximately one-third of them relapse. The mechanisms of refractoriness have been investigated by numerous studies but have not been fully clarified. Hormonal therapy resistance, particularly aromatase inhibitor (AI) resistance, may be related to the acquisition of alternative intracellular ER signaling. We have been investing the mechanisms using cancer specimens and cell lines by monitoring the transcription activity of ERs. AI refractory specimens showed diverse ER activity in the adenovirus estrogen receptor element-green fluorescent protein (ERE-GFP) assay and varied sensitivity to anti-estrogens, indicating the existence of multiple resistant mechanisms. We established six different types of cell lines mimicking AI resistance from ERE-GFP-introduced ER-positive cell lines. They revealed that multiple and alternative ER activating pathways were involved in the resistance, such as phosphorylation-dependent or androgen metabolite-dependent mechanisms. The response to fulvestrant and mammalian target of rapamycin inhibitor also varied among individual resistant cell lines. These results indicate that further subclassification of ER-positive breast cancer is extremely important to decide the therapeutic management of not only hormonal therapy but also new molecular target therapy.
Collapse
Affiliation(s)
- Shin-ichi Hayashi
- Department of Molecular and Functional Dynamics, and Center for Regulatory Epigenomics and Diseases, Tohoku University Graduate School of Medicine, Aoba-ku, Sendai, Japan,
| | | |
Collapse
|