Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0278488 (metastatic breast cancer)
 7,812 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Breast cancer remains a leading cause of disease and death among women throughout the world. Despite advances in drug therapy, development of novel and improved drugs for breast cancer continues to be of great interest. Lapatinib is a novel dual receptor tyrosine kinase inhibitor that is a selective and potent inhibitor of ErbB-1 and ErbB-2 tyrosine kinases, both of which are growth promoting factors overexpressed in some breast cancers. Cell-based assays have proven lapatinib to be a potent inhibitor of ErbB-1 and ErbB-2 activation and breast cancer cell proliferation. In pharmacokinetic studies, lapatinib has shown mostly linear elimination kinetics over the daily dose range of 10-1600 mg and is metabolized by CYP3A4/5 and CYP2C19. Phase I, II, and III clinical trials involving lapatinib as monotherapy or in combination have shown promise for the treatment of advanced and metastatic breast cancer. Drug-drug interactions may occur secondary to concomitant administration of either CYP450 inhibitors or inducers. While lapatinib appear to be a promising addition to breast cancer therapy, several questions remain to be answered before its optimal role is elucidated.
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PMID:A review of lapatinib ditosylate in the treatment of refractory or advanced breast cancer. 1847 89

Targeting the human epidermal growth factor receptor type 2 (HER2) in breast cancer patients whose tumors overexpress HER2 has been clearly demonstrated to be effective in clinical trials with the monoclonal antibody trastuzumab. Not all patients, however, respond to trastuzumab therapy. Lapatinib is an oral receptor tyrosine kinase inhibitor that targets HER2 and the EGFR. Preclinical data reveal that lapatinib has activity in trastuzumab-resistant cell lines as well as synergistic activity with trastuzumab. In a pivotal phase III trial, a combination of lapatinib and capecitabine significantly decreased the risk of disease progression relative to capecitabine alone in women with HER2-positive advanced or metastatic breast cancer previously treated with anthracyclines, taxanes, and trastuzumab. Other trials are evaluating lapatinib in inflammatory breast cancer--for which encouraging data have been reported--in combination with hormone therapy, in combination with trastuzumab, and as an adjunct to adjuvant therapy for early-stage disease. Notably, lapatinib has not been associated with serious or symptomatic cardiotoxicity in clinical trials. It can cross the blood-brain barrier and might therefore have a role in preventing central-nervous-system progression. These features make lapatinib an ideal agent to evaluate more fully in HER2-positive metastatic and early-stage breast cancer.
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PMID:Drug Insight: intracellular inhibitors of HER2--clinical development of lapatinib in breast cancer. 1859 99

Three prominent hallmarks of triple-negative/basal-like breast carcinomas, a subtype of breast cancer gene phenotype associated with poor relapse-free and overall survival, are overexpression of the epidermal growth factor receptor (EGFR), hyperactivation of the MEK/ERK transduction pathway and high sensitivity to DNA-damaging agents. The cytotoxic interaction between EGFR inhibitors (monoclonal antibodies such as cetuximab and small molecule tyrosine kinase inhibitors such as gefitinib) and DNA cross-linking agents (e.g. platinum derivatives) might represent a promising combination for the treatment of triple-negative/basal-like breast tumors that are dependent upon EGFR/MEK/ERK signaling. We evaluated the growth and molecular interactions of the anti-EGFR antibody cetuximab (erbitux) and the DNA cross-linking agent cisplatin (cis-diammedichloroplatinum; CDDP) in the gefitinib-resistant MDA-MB-468 breast cancer cell line, an in vitro model system that shows many of the recurrent basal-like molecular abnormalities including ER-PR-HER2-negative status, TP53 deficiency, EGFR overexpression, PTEN loss and constitutive activation of the MEK/ERK pathway. Unlike other basal-like breast cancer models, MDA-MB-468 cells do not carry mutations of the key DNA repair gene BRCA1. Concurrent treatment with sub-optimal doses of cetuximab significantly enhanced CDDP-induced apoptotic cell death. However, an isobologram-based mathematical assessment of the nature of the interaction revealed a loss of synergism when employing a high-dose of cetuximab. Since BRCA1 depletion has been found to decrease DNA damage repair and cell survival in MDA-MB-468 cells when treated with DNA-damaging drugs, we employed ELISA-based quantitative analyses to measure BRCA1 protein levels in CDDP+/- cetuximab-treated cells. Cetuximab as single agent was as efficient as CDDP at increasing BRCA1 protein expression. Interestingly, cetuximab co-exposure significantly antagonized the ability of CDDP to up-regulate BRCA1 expression. Low-scale phosphor-proteomic approaches [i.e. phospho-receptor tyrosine kinase (RTK) and phospho-mitogen-activated protein kinases (MAPKs) Array Proteome Profiler capable of simultaneously identifying the relative levels of phosphorylation of 42 different RTKs and 23 different MAPKs and other serine/threonine kinases, respectively] revealed the ability of Cetuximab, as single agent, to paradoxically induce hyper-phosphorylation of EGFR while concomitantly deactivating p42/44 (ERK1/ERK2) MAPK. Unexpectedly, ELISA-based quantitative analyses of EGFR protein content demonstrated that simultaneous exposure to cetuximab and optimal doses of CDDP completely depleted EGFR protein in MDA-MB-468 cells. Although these findings preclinically support, at least in part, ongoing clinical trials for 'triple-negative/basal-like' metastatic breast cancer patients who are receiving either cetuximab alone versus cetuximab plus carboplatin (http://www.clinicaltrials.gov/ct/show/NCT00232505), the unexpected ability of CDDP to promote a complete depletion of the cetuximab target EGFR further suggests that treatment schedules, cetuximab/CDDP doses and BRCA1 status should be carefully considered when combining anti-EGFR antibodies and platinum derivatives in triple-negative/basal-like breast carcinomas.
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PMID:Growth and molecular interactions of the anti-EGFR antibody cetuximab and the DNA cross-linking agent cisplatin in gefitinib-resistant MDA-MB-468 cells: new prospects in the treatment of triple-negative/basal-like breast cancer. 1902 Jul 49

Phospholipase D (PLD) is an essential enzyme responsible for the production of the lipid second messenger phosphatidic acid. Phosphatidic acid participates in both G protein-coupled receptor and receptor tyrosine kinase signal transduction networks. The lack of potent and isoform-selective inhibitors has limited progress in defining the cellular roles of PLD. We used a diversity-oriented synthetic approach and developed a library of PLD inhibitors with considerable pharmacological characterization. Here we report the rigorous evaluation of that library, which contains highly potent inhibitors, including the first isoform-selective PLD inhibitors. Specific members of this series inhibit isoforms with >100-fold selectivity both in vitro and in cells. A subset of inhibitors was shown to block invasiveness in metastatic breast cancer models. These findings demonstrate the power of diversity-oriented synthesis combined with biochemical assays and mass spectrometric lipid profiling of cellular responses to develop the first isoform-selective PLD inhibitors--a new class of antimetastatic agents.
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PMID:Design of isoform-selective phospholipase D inhibitors that modulate cancer cell invasiveness. 1913 75

Metastasis underlies the majority of cancer-related deaths. Thus, furthering our understanding of the molecular mechanisms that enable tumor cell dissemination is a vital health issue. Epithelial-to-mesenchymal transitions (EMTs) endow carcinoma cells with enhanced migratory and survival attributes that facilitate malignant progression. Characterization of EMT effectors is likely to yield new insights into metastasis and novel avenues for treatment. We show that the presence of the receptor tyrosine kinase Axl in primary breast cancers independently predicts strongly reduced overall patient survival, and that matched patient metastatic lesions show enhanced Axl expression. We demonstrate that Axl is strongly induced by EMT in immortalized mammary epithelial cells that establishes an autocrine signaling loop with its ligand, Gas6. Epiallelic RNA interference analysis in metastatic breast cancer cells delineated a distinct threshold of Axl expression for mesenchymal-like in vitro cell invasiveness and formation of tumors in foreign and tissue-engineered microenvironments in vivo. Importantly, in two different optical imaging-based experimental breast cancer models, Axl knockdown completely prevented the spread of highly metastatic breast carcinoma cells from the mammary gland to lymph nodes and several major organs and increased overall survival. These findings suggest that Axl represents a downstream effector of the tumor cell EMT that is required for breast cancer metastasis. Thus, the detection and targeted treatment of Axl-expressing tumors represents an important new therapeutic strategy for breast cancer.
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PMID:Axl is an essential epithelial-to-mesenchymal transition-induced regulator of breast cancer metastasis and patient survival. 2008 Jun 45

Aromatase inhibitors have largely replaced tamoxifen as the first-line treatment for postmenopausal women with metastatic, hormone receptor-positive (HR+) breast cancer. However, many patients develop clinical resistance with prolonged treatment, and oestrogen deprivation following aromatase inhibition can result in loss of bone mineral density. Furthermore, most patients with metastatic breast cancer develop bone metastases, and the resulting adverse skeletal-related events are a significant cause of patient morbidity. Src, a non-receptor tyrosine kinase, is a component of signalling pathways that regulate breast cancer cell proliferation, invasion and metastasis as well as osteoclast-mediated bone turnover. Preclinical evidence also suggests a role for Src in acquired endocrine resistance. As such, Src inhibition represents a logical strategy for the treatment of metastatic breast cancer. In vitro, combination therapy with Src inhibitors and endocrine agents, including aromatase inhibitors, has been shown to inhibit the proliferation and metastasis of both endocrine-responsive and endocrine-resistant breast cancer cell lines more effectively than either of the therapy alone. Src inhibition has also been shown to suppress osteoclast formation and activity. Combination therapy with aromatase inhibitors and Src inhibitors therefore represents a novel approach through which the development of both acquired resistance and bone pathology could be delayed. Data from clinical trials utilising such combinations will reveal if this strategy has the potential to improve patient outcomes.
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PMID:Combining Src inhibitors and aromatase inhibitors: a novel strategy for overcoming endocrine resistance and bone loss. 2047 23

Roche Holding AG, and its subsidiaries Genentech Inc and Chugai Pharmaceutical Co Ltd, are developing trastuzumab emtansine (trastuzumab-DM1) for the treatment of HER2+ metastatic breast cancer. Trastuzumab emtansine is a tumor-activated prodrug resulting from the conjugation of the humanized anti-HER2 mAb trastuzumab, which has been used in the treatment of breast cancer for over 10 years, with ImmunoGen Inc's cytotoxic and antimitotic maytansine derivative DM1. The maytansinoids bind microtubules in a manner similar to the vinca alkaloids; however, maytansinoids have been recognized to be 20- to 100-fold more potent at blocking mitosis. Nevertheless, the use of these compounds as single agents is limited by toxicity. By conjugating DM1 with trastuzumab, the delivery of the cytotoxic agent to target cells is more specific and reduces the safety concerns. In preclinical studies, the conjugation was effective in breast cancer cell lines resistant to trastuzumab, and demonstrated complete tumor regression in SCID mice bearing KPL4 breast cancer xenografts. Clinically, trastuzumab emtansine exhibited efficacy in patients with HER2+ metastatic breast cancer who had progressed on previous chemotherapy regimens or with trastuzumab therapy. Furthermore, preclinical studies have reported that trastuzumab emtansine potentiates the effect of a number of chemotherapeutic agents (including carboplatin, 5-fluorouracil and docetaxel), other antibodies, receptor tyrosine kinase inhibitors and PI3K inhibitors, and many of these combinations are set to be tested in humans. Trastuzumab emtansine offers an exciting new option for the treatment of patients with refractory, metastatic breast cancer.
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PMID:Trastuzumab emtansine, an antibody-drug conjugate for the treatment of HER2+ metastatic breast cancer. 2052 Dec 24

Vascular endothelial growth factor regulates neoplastic angiogenesis through production of endothelium-derived NO. We performed a prospective evaluation of vascular function during treatment with vandetanib, a vascular endothelial growth receptor 2 and 3 receptor tyrosine kinase inhibitor, to determine the effects of vascular endothelial growth receptor signal interruption on endothelial function in humans. Seventeen patients with stage IV breast cancer received dose-escalated vandetanib in combination with low-dose oral chemotherapy. We measured blood pressure, systemic nitrate/nitrite levels, and brachial artery vascular function. In vitro analyses of cultured endothelial cells were performed to determine the effect of vandetanib on NO production, akt(473) phosphorylation, and endothelial NO synthase protein content and membrane localization. Vandetanib treatment for 6 weeks significantly increased blood pressure, decreased resting brachial artery diameter, and decreased plasma systemic nitrate/nitrite levels compared with baseline. Flow-mediated vasodilation was preserved, and no change was noted in nitroglycerin-mediated vasodilation. In vitro, endothelial cell nitrite levels and akt(473) phosphorylation were reduced and vascular endothelial growth receptor 2 levels did not change, but endothelial NO synthase membrane concentration doubled. Vandetanib reduces constitutive NO production and increases blood pressure, yet flow-stimulated NO bioavailability was preserved. Changes in vascular function with tyrosine kinase inhibition are complex and require further study in humans.
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PMID:Contrary effects of the receptor tyrosine kinase inhibitor vandetanib on constitutive and flow-stimulated nitric oxide elaboration in humans. 2148 57

Overexpression of the ErbB2 receptor tyrosine kinase in breast cancer contributes to tumor development and is associated with poor prognosis. However, the mechanism by which ErbB2 might contribute to metastasis is not well defined. To identify genes that mediate ErbB2-driven cell motility, we performed differential gene expression analysis of ErbB2-expressing migrating breast cancer cells vs mutant ErbB2-expressing non-migrating cells. Among the genes that were specifically induced in migrating cells were known transcriptional targets of ErbB2, such as matrix metalloproteinases, and novel ErbB2 targets. Contribution of selected candidate genes to ErbB2-driven cell motility was tested by small interfering RNA targeting. Knockdown of the soluble form of ST2 (sST2), also called interleukin-1 receptor-like 1, one of the most robustly induced genes, decreased ErbB2-induced cell motility in two different cell lines. In response to ErbB2 activation, sST2 protein expression and secretion were increased. Moreover, recombinant sST2 associated with the plasma membrane and sST2-blocking antibodies reduced ErbB2-induced motility. Interestingly, cells from metastatic breast tumors secreted higher levels of sST2 than primary tumor cells. Finally, sST2 was found at high levels in the serum of metastatic breast cancer patients. Our data suggest that sST2 contributes to breast cancer cell motility and that sST2 secretion is associated with metastasis.
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PMID:Gene expression profiling identifies sST2 as an effector of ErbB2-driven breast carcinoma cell motility, associated with metastasis. 2210 64

Approximately 20-30% of breast cancers show increased expression of the HER2 receptor tyrosine kinase. Trastuzumab (Herceptin) is a clinically approved anti-HER2 monoclonal antibody. Many patients with HER2-overexpressing metastatic breast cancer respond to trastuzumab; however, a subset display primary drug resistance. In addition, many patients who initially respond to trastuzumab ultimately develop disease progression. Multiple molecular mechanisms contributing to trastuzumab resistance have been proposed in the literature. These mechanisms include cross-signaling from related HER/erbB receptors and compensatory signaling from receptors outside of the HER/erbB family, including receptors for insulin-like growth factor-I, vascular endothelial growth factor, and transforming growth factor beta. The major downstream signaling pathway activated by HER2 cross-talk is PI3K/mTOR, and a potential integrator of receptor cross-talk is Src-focal adhesion kinase (FAK) signaling. PI3K, Src, and FAK have independently been implicated in trastuzumab resistance. In this review, we will discuss pharmacological inhibition of HER2 cross-talk as a strategy to treat trastuzumab-refractory HER2-overexpresssing breast cancer.
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PMID:Pharmacological strategies to overcome HER2 cross-talk and Trastuzumab resistance. 2222 14


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