scholarly journals Targeted cytotoxic bombesin analog AN-215 effectively inhibits experimental human breast cancers with a low induction of multi-drug resistance proteins

2005 ◽  
Vol 12 (4) ◽  
pp. 999-1009 ◽  
Author(s):  
Jörg B Engel ◽  
Andrew V Schally ◽  
Gabor Halmos ◽  
Benjamin Baker ◽  
Attila Nagy ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Drug Resistance ◽  
Cell Lines ◽  
Antitumor Effect ◽  
Multi Drug Resistance ◽  
Breast Cancers ◽  
Human Breast ◽  
Resistance Protein ◽  
Grp Receptors ◽  
Mdr 1

The cytotoxic analog of bombesin (BN)/gastrin releasing peptide (GRP) AN-215 consisting of 2-pyrrolinodoxorubicin (AN-201), a superactive derivative of doxorubicin linked to a bombesin analog carrier, displays a high affinity to BN/GRP receptors and can be targeted to tumors that express these receptors. We evaluated the antitumor effect and the toxicity of AN-215 in 5 human breast cancer cell lines xenografted into nude mice. In addition, we measured the mRNA expression of multi drug resistance protein 1 (MDR-1), multi drug resistance related protein 1 (MRP-1) and breast cancer resistance protein (BCRP) by real-time PCR analysis after treatment with AN-215. All five cell lines expressed BN/GRP receptors, and AN-215 significantly (P<0.05) inhibited tumor growth in all models, while its cytotoxic radical AN-201 had no significant effect in four models. In MX-1 tumors, AN-201 had a significantly weaker antitumor effect than AN-215. The effect of AN-215 was nullified by a blockade of BN/GRP receptors with a bombesin antagonist. Low or no induction of MDR-1, MRP-1 and BCRP occurred after treatment with AN-215. In conclusion, targeted chemotherapy with the cytotoxic BN/GRP analog AN-215 strongly inhibits breast cancers that express BN/GRP receptors and might provide a new treatment modality for mammary carcinoma.

scholarly journals Extracellular Calcium-Sensing Receptor Expression and Its Potential Role in Regulating Parathyroid Hormone-Related Peptide Secretion in Human Breast Cancer Cell Lines*

Endocrinology ◽  
2000 ◽  
Vol 141 (12) ◽  
pp. 4357-4364 ◽  
Author(s):  
Jennifer L. Sanders ◽  
Naibedya Chattopadhyay ◽  
Olga Kifor ◽  
Toru Yamaguchi ◽  
Robert R. Butters ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Lines ◽  
Cancer Cell ◽  
Breast Cancer Cell ◽  
Human Breast Cancer ◽  
Cancer Cell Lines ◽  
Human Breast Cancer Cell ◽  
Breast Cancer Cell Lines ◽  
Breast Cancers ◽  
Human Breast

Abstract Metastasis of breast cancer to bone occurs with advanced disease and produces substantial morbidity. Secretion of PTH-related peptide (PTHrP) from breast cancer cells is thought to play a key role in osteolytic metastases and is increased by transforming growth factor-β (TGFβ), which is released from resorbed bone. Elevated extracellular calcium (Cao2+) also stimulates PTHrP secretion from various normal and malignant cells, an action that could potentially be mediated by the Cao2+-sensing receptor (CaR) originally cloned from the parathyroid gland. Indeed, we previously showed that both normal breast ductal epithelial cells and primary breast cancers express the CaR. In this study we investigated whether the MCF-7 and MDA-MB-231 human breast cancer cell lines express the CaR and whether CaR agonists modulate PTHrP secretion. Northern blot analysis and RT-PCR revealed bona fide CaR transcripts, and immunocytochemistry and Western analysis with a specific anti-CaR antiserum demonstrated CaR protein expression in both breast cancer cell lines. Furthermore, elevated Cao2+ and the polycationic CaR agonists, neomycin and spermine, stimulated PTHrP secretion dose dependently, with maximal, 2.1- to 2.3-fold stimulation. In addition, pretreatment of MDA-MB-231 cells overnight with TGFβ1 (0.2, 1, or 5 ng/ml) augmented both basal and high Cao2+-stimulated PTHrP secretion. Thus, in PTHrP-secreting breast cancers metastatic to bone, the CaR could potentially participate in a vicious cycle in which PTHrP-induced bone resorption raises the levels of Cao2+ and TGFβ within the bony microenvironment, which then act in concert to evoke further PTHrP release and worsening osteolysis.

A novel therapeutic strategy for ER-negative human breast cancers, targeting AP-1 activity

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 14129-14129
Author(s):  
K. Sakaguchi ◽  
H. Nakajima ◽  
I. Fujiwara ◽  
N. Mizuta ◽  
J. Magae
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Cell Lines ◽  
Cancer Cell ◽  
Breast Cancer Cell ◽  
Human Breast Cancer ◽  
Human Breast Cancer Cell ◽  
Breast Cancers ◽  
Human Breast ◽  
Er Positive

14129 Background: While agents targeting estrogen receptors are the most effective in adjuvant therapy for human breast cancers expressing estrogen receptor(ER), breast cancers lacking ER are clinically serious, because they are highly malignant and exhibit resistance to the usual anti-cancer drugs, including estrogen receptor-antagonists and DNA breaking agents. Although a transcription factor, AP-1, is known to be related to tumor malignancy including metastasis, invasion and drug-resistance, it remains to be elucidated how AP-1 plays in development and expression of malignant characters of human breast cancers. Methods and Results: Here, we used MX-1, a human breast cancer cell line lacking ER and several ER positive cell lines, to clarify the roles of AP-1 and the therapeutic efficacy of ascochlorin, a newly developed prenylphenol antibiotic on ER-negative breast cancer. We found that MX-1 exhibited higher AP-1 activity and expressed higher levels of c-Jun, c-Fos and Fra-1 when compared with conventional ER-positive human breast cancer cell lines. Consistent with this study in vitro, histological study on human breast cancer tissues suggests that ER-negative cancers express high Fra-1 protein, and that paclitaxel- sensitive cancers express low Fra-1 protein. The ascochlorin, which inhibits AP-1 through the Erk signaling pathway, suppressed the AP-1 activity of MX-1 cells, and selectively killed MX-1 cells, partly due to induction of apoptosis. Moreover, administration of ascochlorin elongated life span of mice intraperitoneally implanted with murine mammary carcinoma cells. Conclusions: Our results suggest that AP-1 is an effective clinical target molecule for the treatment of ER-negative human breast cancer, and that ascochlorin is promising therapeutic agent for these refractory breast cancers. No significant financial relationships to disclose.

Biopsy-driven study to identify biomarkers of drug resistance in patients with triple-negative breast cancer.

2012 ◽  
Vol 30 (30_suppl) ◽  
pp. 87-87
Author(s):  
Adriana Aguilar-Mahecha ◽  
Josiane Lafleur ◽  
Elaheh Ahmadzadeh ◽  
Ewa Przybytkowski ◽  
Carole Seguin ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Drug Resistance ◽  
Cell Lines ◽  
Triple Negative ◽  
Acquired Resistance ◽  
Great Difficulty ◽  
Clinical Samples ◽  
Drug Resistant ◽  
Breast Cancers ◽  
Breast Cancer Patients

87 Background: Resistance to chemotherapy is the underlying cause of death in most patients dying of breast cancer. Patients with early stages of breast cancer whose tumor is or becomes resistant to chemotherapy have a poor prognosis, while women with advanced breast cancer live as long as their tumors respond to chemotherapy. Because of the great difficulty of obtaining clinical samples from drug resistant tumors in patients, there is scant information about molecular factors from actual drug resistant tumors. This project aims to systematically profile resistant triple negative breast cancers (TNBCs) in order to discover molecular “resistance” genes/proteins as a first step to develop strategies to overcome drug resistance. Methods: Paired biopsies are collected from TNBC patients (NCT01276899). Four needle core biopsies are collected before the initiation of treatment and 2 weeks before surgery or at the time of progression in the neoadjuvant and metastatic settings respectively. Paired biopsies will undergo Next Gen Sequencing, flow sorted aCGH analysis, gene expression and miRNA profiling as well as phosphoproteomic profiling using reverse phase protein arrays. Results: We have currently enrolled 28 patients in the neoadjuvant setting and 3 metastatic patients. We have standardized the methods of collection and processing of tissue and blood specimens to ensure their molecular integrity and compatibility with different genomic and proteomic molecular platforms. Analysis of tumor cellularity has been incorporated into our quality control and we have optimized the extraction of nucleic acids to obtain high yields and optimal quality. In parallel, we have generated acquired resistance to paclitaxel in a panel of TNBC cell lines. These cell lines will also undergo genomic profiling and exome sequencing to identify molecular markers of resistance that will be correlated with the markers found in patient samples. Conclusions: This project will allow us to identify the molecular factors responsible for drug resistance in TNBCs and enable the elaboration of strategies to overcome resistance.

Simultaneous, quantitative detection of multiple biomarkers in human breast cancers using multicolor nanoparticles

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 619-619
Author(s):  
A. H. Al-Hajj ◽  
M. V. Yezhelyev ◽  
T. Liu ◽  
R. M. O’Regan
Keyword(s):  
Breast Cancer ◽  
Growth Factor ◽  
Cell Lines ◽  
Cancer Cell ◽  
Breast Cancer Cell ◽  
Growth Factor Receptor ◽  
Cancer Cell Lines ◽  
Breast Cancer Cell Lines ◽  
Breast Cancers ◽  
Human Breast

619 Background: Conventional methods of detecting breast cancer biomarkers are hampered by a lack of adequate quantification and/or an inability to detect multiple targets on small quantities of tissue. We have previously demonstrated that estrogen receptor (ER), progesterone receptor (PR) and HER2/neu (HER2) can be detected and quantified simultaneously using antibodies (Abs) directly conjugated to nanoparticles, called quantum dots (QDs), on single breast cancer sections (ASCO 2005). We have expanded our assay to use multicolored QDs conjugated directly to Abs (QD-Abs) to detect and quantify simultaneously ER, PR, and HER2, along with 3 putative biomarkers, epidermal growth factor receptor (EGFR), mammalian target of Rapamycin (mTOR), and insulin-like growth factor receptor (IGFR), in breast cancer cell lines and human breast cancers. Methods: We used multicolored QDs directly conjugated to primary Abs to detect the 6 proteins in breast cancer cell lines (MCF-7, BT474, MDA-231) and single sections of human breast cancers. The 6 proteins were quantified using spectral separation microscopy, and compared to Western blotting. Results: We detected all 6 proteins simultaneously using QD-Abs in breast cancer cell lines and breast tumors. Using hyper-spectral imaging and wavelength-resolved spectroscopy, we separated all 6 fluorescent signals, and quantified the expression of each protein detected using QD-Abs. Quantification of the biomarkers showed good correlation with Western blotting. Conclusions: These results are proof of principle that 6 proteins can be simultaneously quantified using QD-Abs in single breast cancer sections. The use of multiplex QDs offers a novel method of determining the proteome of an individual breast cancer on single breast cancer sections. With the expanding use of targeted therapies in breast cancer, the ability to detect multiple proteins on small breast cancer specimens using QD-Abs, could allow not only the accurate selection of therapy, but a unique method of determining the activity of specific targeted agents. No significant financial relationships to disclose.

scholarly journals TCPTP Regulates SFK and STAT3 Signaling and Is Lost in Triple-Negative Breast Cancers

2012 ◽  
Vol 33 (3) ◽  
pp. 557-570 ◽  
Author(s):  
Benjamin J. Shields ◽  
Florian Wiede ◽  
Esteban N. Gurzov ◽  
Kenneth Wee ◽  
Christine Hauser ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Lines ◽  
Cancer Cell ◽  
Breast Cancer Cell ◽  
Human Breast Cancer ◽  
Cancer Cell Lines ◽  
Breast Cancer Cell Lines ◽  
Breast Cancers ◽  
Human Breast ◽  
Stat3 Signaling

ABSTRACTTyrosine phosphorylation-dependent signaling, as mediated by members of the epidermal growth factor receptor (EGFR) family (ErbB1 to -4) of protein tyrosine kinases (PTKs), Src family PTKs (SFKs), and cytokines such as interleukin-6 (IL-6) that signal via signal transducer and activator of transcription 3 (STAT3), is critical to the development and progression of many human breast cancers. EGFR, SFKs, and STAT3 can serve as substrates for the protein tyrosine phosphatase TCPTP (PTPN2). Here we report that TCPTP protein levels are decreased in a subset of breast cancer cell linesin vitroand that TCPTP protein is absent in a large proportion of “triple-negative” primary human breast cancers. Homozygous TCPTP deficiency in murine mammary fat padsin vivois associated with elevated SFK and STAT3 signaling, whereas TCPTP deficiency in human breast cancer cell lines enhances SFK and STAT3 signaling. On the other hand, TCPTP reconstitution in human breast cancer cell lines severely impaired cell proliferation and suppressed anchorage-independent growthin vitroand xenograft growthin vivo. These studies establish TCPTP's potential to serve as a tumor suppressor in human breast cancer.

scholarly journals A Study of Multiple Drug Resistance Mechanisms Improved Against Bortezomib on Multiple Myeloma Cell Lines In Vitro.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4183-4183
Author(s):  
Tolga Uyuklu ◽  
A. Ugur Ural ◽  
Meral Sarper ◽  
Ferit Avcu ◽  
Yusuf Baran ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Cell Lines ◽  
Resistance Mechanisms ◽  
Resistant Cell ◽  
Chemotherapeutic Agents ◽  
Multi Drug Resistance ◽  
Resistance Protein ◽  
One Year ◽  
Rpmi 8226

Abstract The most important problem in the treatment of Multiple Myeloma (MM) is the multi drug resistance (MDR) observed before and after the treatment. For this reason in MM cases an early resistance to treatment can be developed or the disease can relapsed in early period. Yet, there has been no improved drug resistance against proteazom inhibitor Bortezomib (Bor), which is used alone or with other chemotherapeutic agents in resistant or relapsed MM cases. In this study, bortezomib resistant human MM cell lines; RPMI-8226, secreting lambda light chain, and ARH-77, secreting IgG, were developed and responsible resistance mechanisms were investigated. For this purpose, by exposing to the cells to sequentially gradual doses of Bor in vitro conditions, resistant cell lines were acquired throughout one year. The IC50 values for Bor were determined after 48 hour incubation by MTT cytotoxicity assay (IC50:1,16nM for RPMI-8226 and IC80:0,6nM for ARH-77) against wild type cells. Throughout one year some cell lines resistant to 1,3nM Bor were acquired by performing Bor to both cell lines in gradual doses. In resistant cell lines IC50:18,07 for RPMI-8226 and IC50:97,56 nM for ARH-77 were determined by MTT assay. In parallel of the gradual increase in drug concentration; the expression changes of the genes of ATP binding cassette protein; MDR1 (Multi Drug Resistance Protein), MRP1 (Multi Drug Resistance Associated Protein), BCRP (Breast Cancer Resistance Protein); and LRP (Lung Resistant Protein) which is responsible for accumulation of the drug in cytoplasm with the aid of nuclear membrane were determined with Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) and densitometric analysis. In resistant cells, high expression of MDR1, MRP1, BRCP and LRP genes showed that; pumping the drug out of the cell membrane and decrease in accumulation of the drug in the cytoplasm had effects on the resistant mechanisms against Bor. Furthermore, expression changes of an important sing of apoptosis ‘caspase-3’, pro-apoptotic ‘bax’ and an anti-apoptotic ‘bcl-2’ genes were examined by RT-PCR and we could come to a point that when compared the sensitive cells to resistant cells, expression of caspase-3 gene and pro-apoptotic bax protein decreased but bcl-2 gene expression increased in resistant cell lines. Finally, we concluded that resistant cell lines acquired resistance against apoptosis by means of mitochondria. By means of this project, the genes which are responsible for secondary drug resistance in ARH-77 and RPMI-8226 MM cell lines in vitro conditions against Bor were determined. Also resistance mechanisms against apoptosis were demonstrated. Cross resistance to different chemotherapeutic agents mechanisms are still continuing.

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