Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.7.12.2 (MEK)
18,161 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Melanoma today is considered as a spectrum of melanocytic malignancies characterised by clinical and molecular features, including targetable mutations in several kinases such as BRAF or c-KIT. The successful development of therapies targeting these mutations has resulted in new specific treatment options. These include vemurafenib, dabrafenib, trametinib, imatinib and other kinase inhibitors that are selected when the respective mutation is present. The BRAF inhibitor vemurafenib has resulted in improved survival in patients with BRAF-mutated advanced melanoma. Dabrafenib has shown similar efficacy. The MEK inhibitor trametinib also improved overall survival. In addition, the MEK inhibitor MEK 162 was investigated in a phase II clinical trial and showed promising efficacy in terms of response rate and progression-free survival (PFS) in NRAS-mutated melanomas. After this first success in the treatment of advanced melanoma, there is expectation that combinations of kinase inhibitors will additionally improve overall survival rates and PFS in advanced melanoma.
...
PMID:Targeted therapy in melanoma - the role of BRAF, RAS and KIT mutations. 2621 17

Melanoma originated from melanocytes is the most aggressive type of skin cancer with limited treatment options. New targeted therapeutic options with the discovery of BRAF and MEK inhibitors have shown significant survival benefits. Despite the recent progress, development of chemoresistance and systemic toxicity remains a challenge for treating metastatic melanoma. While the response from the first line of treatment against melanoma using dacarbazine remains only 5-10%, the prolonged use of targeted therapy against mutated oncogene BRAF develops chemoresistance. In this review, we will discuss the nanoparticle-based strategies for encapsulation and conjugation of drugs to the polymer for maximizing their tumor distribution through enhanced permeability and retention effect. We will also highlight photodynamic therapy and design of melanoma-targeted nanoparticles.
...
PMID:Nanoparticle-mediated drug delivery for treating melanoma. 2624 18

Melanoma is the most lethal form of skin cancer and successful treatment of metastatic melanoma remains challenging. BRAF/MEK inhibitors only show a temporary benefit due to rapid occurrence of resistance, whereas immunotherapy is mainly effective in selected subsets of patients. Thus, there is a need to identify new targets to improve treatment of metastatic melanoma. To this extent, we searched for markers that are elevated in melanoma and are under regulation of potentially druggable enzymes. Here, we show that the pro-proliferative transcription factor FOXM1 is elevated and activated in malignant melanoma. FOXM1 activity correlated with expression of the enzyme Pin1, which we found to be indicative of a poor prognosis. In functional experiments, Pin1 proved to be a main regulator of FOXM1 activity through MEK-dependent physical regulation during the cell cycle. The Pin1-FOXM1 interaction was enhanced by BRAF(V600E), the driver oncogene in the majority of melanomas, and in extrapolation of the correlation data, interference with\ Pin1 in BRAF(V600E)-driven metastatic melanoma cells impaired both FOXM1 activity and cell survival. Importantly, cell-permeable Pin1-FOXM1-blocking peptides repressed the proliferation of melanoma cells in freshly isolated human metastatic melanoma ex vivo and in three-dimensional-cultured patient-derived melanoids. When combined with the BRAF(V600E)-inhibitor PLX4032 a robust repression in melanoid viability was obtained, establishing preclinical value of patient-derived melanoids for prognostic use of drug sensitivity and further underscoring the beneficial effect of Pin1-FOXM1 inhibitory peptides as anti-melanoma drugs. These proof-of-concept results provide a starting point for development of therapeutic Pin1-FOXM1 inhibitors to target metastatic melanoma.
...
PMID:Targeted inhibition of metastatic melanoma through interference with Pin1-FOXM1 signaling. 2627 95

Melanoma is the most deadly form of cutaneous malignancy, and its incidence rates are rising worldwide. In melanoma, constitutive activation of the BRAF/MEK/ERK (MAPK) and PI3K/AKT/mTOR (PI3K) signaling pathways plays a pivotal role in cell proliferation, survival and tumorigenesis. A combination of compounds that lead to an optimal blockade of these critical signaling pathways may provide an effective strategy for prevention and treatment of melanoma. The phytochemical fisetin is known to possess anti-proliferative and pro-apoptotic activities. We found that fisetin treatment inhibited PI3K signaling pathway in melanoma cells. Therefore, we investigated the effect of fisetin and sorafenib (an RAF inhibitor) alone and in combination on cell proliferation, apoptosis and tumor growth. Combination treatment (fisetin + sorafenib) more effectively reduced the growth of BRAF-mutated human melanoma cells at lower doses when compared to individual agents. In addition, combination treatment resulted in enhanced (i) apoptosis, (ii) cleavage of caspase-3 and PARP, (iii) expression of Bax and Bak, (iv) inhibition of Bcl2 and Mcl-1, and (v) inhibition of expression of PI3K, phosphorylation of MEK1/2, ERK1/2, AKT and mTOR. In athymic nude mice subcutaneously implanted with melanoma cells (A375 and SK-MEL-28), we found that combination therapy resulted in greater reduction of tumor growth when compared to individual agents. Furthermore, combination therapy was more effective than monotherapy in: (i) inhibition of proliferation and angiogenesis, (ii) induction of apoptosis, and (iii) inhibition of the MAPK and PI3K pathways in xenograft tumors. These data suggest that simultaneous inhibition of both these signaling pathways using combination of fisetin and sorafenib may serve as a therapeutic option for the management of melanoma.
...
PMID:Fisetin, a phytochemical, potentiates sorafenib-induced apoptosis and abrogates tumor growth in athymic nude mice implanted with BRAF-mutated melanoma cells. 2629 6

Melanoma remains a serious form of skin cancer in Europe and worldwide. Localized, early-stage melanomas can usually be treated with surgical excision. However, the prognosis is poorer for patients with advanced disease. Before 2011, treatment for advanced melanoma included palliative surgery and/or radiotherapy, and chemotherapy with or without immunotherapy, such as interleukin-2. As none of these treatments had shown survival benefits in patients with advanced melanoma, European guidelines had recommended that patients be entered into clinical trials. The lack of approved first-line options and varying access to clinical trials meant that European clinicians relied on experimental regimens and chemotherapy-based treatments when no other options were available. Since 2011, ipilimumab, an immuno-oncology therapy, and vemurafenib and dabrafenib, targeted agents that inhibit mutant BRAF, have been approved by the European Medicines Agency for the treatment of advanced melanoma. More recently, the MEK inhibitor, trametinib, received European marketing authorization for use in patients with BRAF mutation-positive advanced melanoma. In 2014, the anti-PD-1 antibody nivolumab was approved as a first-line therapy in Japan. Whereas nivolumab and another anti-PD-1 antibody, pembrolizumab, were approved as second-line therapies in the USA, their recent approval in Europe are for first-line use based on new clinical trial data in this setting. Together these agents are changing clinical practice and making therapeutic decisions more complex. Here, we discuss current and emerging therapeutic options for the first-line treatment of advanced melanoma, and how these therapies can be optimized to provide the best possible outcomes for patients.
Melanoma Res 2015 Dec
PMID:Integrating first-line treatment options into clinical practice: what's new in advanced melanoma? 2642 64

Melanoma harboring BRAF mutations frequently develop resistance to BRAF inhibitors, limiting the impact of treatment. Here, we establish a mechanism of resistance and subsequently identified a suitable drug combination to overcome the resistance. Single treatment of BRAF mutant melanoma cell lines with vemurafenib or dabrafenib (BRAF inhibitors) alone or in combination with trametinib (MEK1/2 inhibitor) resulted in overexpression of Mcl-1. Overexpression of Mcl-1 in A375 and SK-MEL-28 by transfection completely blocked BRAF and MEK1/2 inhibitor-mediated inhibition of cell survival and apoptosis. Melanoma cells resistant to BRAF inhibitors showed massive expression of Mcl-1 as compared to respective sensitive cell lines. Silencing of Mcl-1 using siRNA completely sensitized resistant melanoma cells to growth suppression and induction of apoptosis by BRAF inhibitors. In vivo, vemurafenib resistant A375 xenografts implanted in athymic nude mice showed substantial tumor growth inhibition when treated with a combination of vemurafenib and Mcl-1 inhibitor or siRNA. Immunohistochemistry and western blot analyses demonstrated enhanced expression of Mcl-1 and activation of ERK1/2 in vemurafenib-resistant tumors whereas level of Mcl-1 or p-ERK1/2 was diminished in the tumors of mice treated with either of the combination. Biopsied tumors from the patients treated with or resistant to BRAF inhibitors revealed overexpression of Mcl-1. These results suggest that the combination of BRAF inhibitors with Mcl-1 inhibitor may have therapeutic advantage to melanoma patients with acquired resistance to BRAF inhibitors alone or in combination with MEK1/2 inhibitors.
...
PMID:Overexpression of Mcl-1 confers resistance to BRAFV600E inhibitors alone and in combination with MEK1/2 inhibitors in melanoma. 2649 53

A 61-year-old man was diagnosed with stage IIIB BRAF V600E mutant melanoma in October 2012. He was treated with a combination therapy of dabrafenib and trametinib. He remained in complete remission for 18 months and the treatment was well tolerated after dose reduction because of pyrexia. In March 2013, he developed bilateral pitting edema of the legs with an erythematous, slightly infiltrated rash on his back and upper arms. His face was edematous, with a heliotrope rash-like aspect. Eye examination showed bilateral blepharitis. Additional blood test showed inflammation and acute kidney injury Rifle category failure. A skin and kidney biopsy indicated a granulomatous inflammation. A complete workup for other causes of granulomatous inflammation was negative. Treatment with dabrafenib and trametinib was stopped and corticosteroids were initiated, with a rapid beneficial effect on both the kidney function and skin rash. When corticosteroids were halted after 1 month, a rapid decline in the kidney function was observed. After reintroduction of corticosteroids, kidney function normalized and steroids could be tapered gradually over 6 months. To our knowledge, interstitial nephritis has not been described in patients on BRAF-targeted nor MEK-targeted therapy for melanoma, although it has been described in a melanoma patient treated with the immune checkpoint inhibitor, ipilimumab. Currently, the patient has no sign of local or distal recurrence of melanoma, notwithstanding that treatment with dabrafenib and trametinib has been stopped for 10 months and no other antimelanoma therapy was initiated.
Melanoma Res 2015 Dec
PMID:Granulomatous nephritis and dermatitis in a patient with BRAF V600E mutant metastatic melanoma treated with dabrafenib and trametinib. 2651 91

Melanoma is the most aggressive and deadly form of cutaneous neoplasm due to its propensity to metastasize. Oncogenic BRAF drives sustained activation of the BRAF/MEK/ERK (MAPK) pathway and cooperates with PI3K/AKT/mTOR (PI3K) signaling to induce epithelial to mesenchymal transition (EMT), leading to cell invasion and metastasis. Therefore, targeting these pathways is a promising preventive/therapeutic strategy. We have shown that fisetin, a flavonoid, reduces human melanoma cell invasion by inhibiting EMT. In addition, fisetin inhibited melanoma cell proliferation and tumor growth by downregulating the PI3K pathway. In this investigation, we aimed to determine whether fisetin can potentiate the anti-invasive and anti-metastatic effects of sorafenib in BRAF-mutated melanoma. We found that combination treatment (fisetin + sorafenib) more effectively reduced the migration and invasion of BRAF-mutated melanoma cells both in vitro and in raft cultures compared to individual agents. Combination treatment also effectively inhibited EMT as observed by a decrease in N-cadherin, vimentin and fibronectin and an increase in E-cadherin both in vitro and in xenograft tumors. Furthermore, combination therapy effectively inhibited Snail1, Twist1, Slug and ZEB1 protein expression compared to monotherapy. The expression of MMP-2 and MMP-9 in xenograft tumors was further reduced in combination treatment compared to individual agents. Bioluminescent imaging of athymic mice, intravenously injected with stably transfected CMV-luciferase-ires-puromycin.T2A.EGFP-tagged A375 melanoma cells, demonstrated fewer lung metastases following combination treatment versus monotherapy. Our findings demonstrate that fisetin potentiates the anti-invasive and anti-metastatic effects of sorafenib. Our data suggest that fisetin may be a worthy adjuvant chemotherapy for the management of melanoma.
...
PMID:Fisetin, a dietary flavonoid, augments the anti-invasive and anti-metastatic potential of sorafenib in melanoma. 2651 21

Melanoma is a malignancy of pigment-producing cells that is driven by a variety of genetic mutations and aberrations. In most cases, this leads to upregulation of the mitogen-activated protein kinase (MAPK) pathway through activating mutations of upstream mediators of the pathway including BRAF and NRAS. With the advent of effective MAPK pathway inhibitors, including the US FDA-approved BRAF inhibitors vemurafenib and dabrafenib and MEK inhibitor trametinib, molecular analysis has become an integral part of the care of patients with metastatic melanoma. In this article, the key molecular targets and strategies to inhibit these targets therapeutically are presented, and the techniques of identifying these targets, in both tissue and blood, are discussed.
...
PMID:The Future of Molecular Analysis in Melanoma: Diagnostics to Direct Molecularly Targeted Therapy. 2651 80

Selective BRAF inhibitors (BRAFi) yield objective responses in 50% of patients with metastatic BRAF V600E mutant melanoma. Adding an MEK inhibitor increases this response rate to 70%. Limited data are available on the outcomes of unresectable stage III patients, and it remains unclear whether BRAF-targeted therapy can be utilized as a neoadjuvant strategy. Data on patients with advanced locoregional BRAF V600E mutant melanoma treated with BRAF-targeted therapy at Moffitt Cancer Center were analyzed to determine response rates, subsequent resection rates after tumor downsizing, pathologic responses, and patient survival. Fifteen patients with locoregional disease treated with BRAF-targeted therapy, either BRAFi alone (vemurafenib; 11 patients) or a combination of BRAFi and an MEK inhibitor (dabrafenib plus trametinib or placebo; four patients), were identified. The median age was 50 years; the median follow-up was 25.4 months. The median BRAF-targeted therapy treatment duration was 6.0 months (range 1.2-29.4 months). Response Evaluation Criteria In Solid Tumors-based evaluation demonstrated objective response in 11 patients (73.3%). Six patients underwent resection of the remaining disease after therapy. Pathological analysis showed complete pathologic response (n=2), partial pathologic response (n=2), or no pathologic response (n=2). Four of six patients undergoing surgery have been alive for more than 2 years, including three patients currently free from active disease. No complications attributable to BRAF-targeted therapy were observed in the perioperative period. Dose reduction or discontinuation because of toxicities occurred in 10/15 patients. Neoadjuvant BRAF-targeted therapy may be effective in advanced locoregional BRAF V600E mutant melanoma patients in increasing resectability, yielding pathological responses, and achieving prolonged survival.
Melanoma Res 2016 Feb
PMID:BRAF inhibition for advanced locoregional BRAF V600E mutant melanoma: a potential neoadjuvant strategy. 2673 60


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---