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)

It is generally accepted that transforming growth factor beta (TGFbeta) is both a tumor suppressor and tumor promoter. Whereas loss or attenuation of TGFbeta signal transduction is permissive for transformation, introduction of dominant-negative TGFbeta receptors into metastatic breast cancer cells has been shown to inhibit epithelial-to-mesenchymal transition, motility, invasiveness, survival, and metastases. In addition, there is evidence that excess production and/or activation of TGFbeta by cancer cells can contribute to tumor progression by paracrine mechanisms involving neoangiogenesis, production of stroma and proteases, and subversion of immune surveillance mechanisms in tumor hosts. These data provide a rationale in favor of blockade of autocrine/paracrine TGFbeta signaling in human mammary tumors with therapeutic intent. Several treatment approaches are currently in early clinical development and have been the focus of our laboratory. These include (1) ligand antibodies or receptor-containing fusion proteins aimed at blocking ligand binding to cognate receptors and (2) small-molecule inhibitors of the type I TGFbeta receptor serine/threonine kinase. Many questions remain about the viability of anti-TGFbeta treatment strategies, the best molecular approach (or combinations) for inhibition of TGFbeta function in vivo, the biochemical surrogate markers of tumor response, the molecular profiles in tumors for selection into clinical trials, and potential toxicities, among others.
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PMID:Dual role of transforming growth factor beta in mammary tumorigenesis and metastatic progression. 1570 90

Akt is a serine/threonine kinase that has been demonstrated to play an important role in survival when cells are exposed to different apoptotic stimuli. Recent studies show that aberrant activation of Akt in breast carcinoma is associated with a poor prognosis and resistance to endocrine therapy and chemotherapy. The Akt signaling pathway is currently attracting considerable attention as a new target for effective therapeutic strategies. We investigated the incidence of Akt activation in 252 primary breast carcinomas and relationships among the activation of Akt, HER2 overexpression, hormone receptor expression, and alteration of the PTEN gene. Eighty-four cases (33.3%) were positive for pAkt expression. pAkt was significantly associated with HER2 overexpression (p<0.0001) and LOH at the PTEN gene locus (p<0.01). There was an inverse correlation between pAkt and PR (p<0.05). We also retrospectively examined the relationship between Akt activation and the efficacy of endocrine therapy for metastatic breast cancer. Of these 36 metastatic breast cancer cases, 12 cases (33.4%) were considered to show positive pAkt expression. In the pAkt-positive patients, endocrine therapy demonstrated worse efficacy than in pAkt-negative patients (p<0.01). In addition, the clinical benefit was the smallest in the patients positive both for HER2 and pAkt (p<0.01). The clinical benefit rate of estrogen deprivation therapy with AI or LH-RH agonist was significantly lower in the pAkt-positive patients than that in the pAkt-negative ones (p<0.05), and there was a tendency for the clinical benefit of SERM to be smaller in the pAkt-positive patients (p=0.09). These findings therefore suggest that Akt activation induces endocrine resistance in metastatic breast cancer, irrespective of the kind of endocrine agents that were administered. Our findings indicate that the activation of Akt in the downstream pathway of HER2 plays an important role in resistance to endocrine therapy for breast cancer. Our findings suggest that pAkt may be a useful predictor of resistance to endocrine therapy for breast cancer, while also suggesting that the inhibition of Akt may increase the efficacy of endocrine therapy.
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PMID:Activation of PI3K/Akt signaling and hormone resistance in breast cancer. 1675 7

Capecitabine is frequently used in the treatment of recurrent/progressive metastatic breast cancer (MBC) after prior anthracycline and taxane therapy. With the intention of improving the efficacy of single agent capecitabine, we initiated a randomized, double-blind, placebo-controlled Phase II study of the novel serine/threonine kinase inhibitor enzastaurin in combination with capecitabine in a heavily pretreated patient population. Patients received capecitabine 1,250 mg/m(2) twice daily plus enzastaurin 500 mg/day, or capecitabine plus placebo. The capecitabine was administered for the first 14 days of each 21 day cycle. The primary outcome was progression-free survival (PFS) using the log-rank test (1-sided significance level of 0.20). Of 109 patients assessed for eligibility, 85 were enrolled, randomized, and treated (42 and 43 patients in each respective treatment group). The study was terminated early following a preplanned futility analysis. Median PFS (95% CI) was 2.8 (2.1-4.6) months with capecitabine plus enzastaurin versus 4.3 (2.9-6.2) months with capecitabine plus placebo (adjusted hazard ratio: 1.728 [1.00-2.97]; P = 0.048). Median overall survival (95% CI) was lower with capecitabine plus enzastaurin than with capecitabine plus placebo (9.9 [7.0-16.6] months vs 14.9 [9.9-19.3] months, P = 0.181). Grade 3/4 adverse events were more frequent with capecitabine plus enzastaurin (42.9% vs 32.6%). Given the lack of PFS benefit, capecitabine plus enzastaurin is unsuitable as therapy for patients with recurrent/progressive MBC after prior anthracycline and taxane therapy. This trial is registered on www.clinicaltrials.gov (identifier: NCT00437294).
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PMID:Phase II, double-blind, randomized trial of capecitabine plus enzastaurin versus capecitabine plus placebo in patients with metastatic or recurrent breast cancer after prior anthracycline and taxane therapy. 2081 15

Triple-negative breast cancer (TNBC) is a highly metastatic breast cancer subtype and due to the lack of hormone receptors and HER2 expression, TNBC has limited therapeutic options with chemotherapy being the primary choice for systemic therapy. LIM Domain Kinase 2 (LIMK2) is a serine/threonine kinase that plays an important role in the regulation of actin filament dynamics. Here, we show that LIM domain kinase 2 (LIMK2) is overexpressed in TNBC, and short-hairpin RNA (shRNA)-mediated LIMK2 knockdown or its pharmacological inhibition blocks metastatic attributes of TNBC cells. To determine the mechanism by which LIMK2 promotes TNBC metastatic progression, we performed stable isotope labeling by amino acids in cell culture (SILAC) based unbiased large-scale phosphoproteomics analysis. This analysis identified 258 proteins whose phosphorylation was significantly reduced due to LIMK2 inhibition. Among these proteins, we identified SRSF protein kinase 1 (SRPK1), which encodes for a serine/arginine protein kinase specific for the SR (serine/arginine-rich domain) family of splicing factors. We show that LIMK2 inhibition blocked SRPK1 phosphorylation and consequentially its activity. Furthermore, similar to LIMK2, genetic inhibition of SRPK1 by shRNAs or its pharmacological inhibition blocked the metastatic attributes of TNBC cells. Moreover, the pharmacological inhibition of LIMK2 blocked metastatic progression in mice without affecting primary tumor growth. In sum, these results identified LIMK2 as a facilitator of distal TNBC metastasis and a potential target for preventing TNBC metastatic progression.
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PMID:LIMK2 promotes the metastatic progression of triple-negative breast cancer by activating SRPK1. 3285 89