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1.
Support Care Cancer ; 32(6): 379, 2024 May 24.
Article in English | MEDLINE | ID: mdl-38789656

ABSTRACT

PURPOSE: The purpose of this phase III randomized double-blinded controlled trial was to investigate the efficacy of a rose geranium in sesame oil (RG) nasal spray compared with an isotonic saline (IS) nasal spray for alleviating nasal vestibulitis symptoms among patients undergoing chemotherapy. METHODS: Patients undergoing active chemotherapy who reported associated nasal symptoms were randomized 1:1 to receive RG or IS, administered twice daily for 2 weeks. Consenting participants completed nasal symptom questionnaires at baseline and then weekly while on treatment. The proportion of patients experiencing improvements in their nasal symptoms 2 weeks after initiating the nasal spray, using a six-point global impression of change score, was estimated within and between each randomized arm, and compared between arms, using Fisher's exact test. The estimated odds ratio was determined (95% confidence interval). RESULTS: One hundred and six patients consented to this study; 43 participants in the RG arm and 41 in the IS arm were evaluable for the primary endpoint. Participants had a mean age of 57.8 years (SD 13.9). Demographic characteristics and baseline nasal symptoms were similar between arms. Of the evaluable participants who received RG, 67.4% reported improved nasal symptoms, compared with 36.6% of the participants who received IS (P = 0.009). Adverse events were sparse and did not differ between arms. CONCLUSION: Rose geranium in sesame oil significantly improves nasal vestibulitis symptoms among patients undergoing chemotherapy. TRIAL REGISTRATION: NCT04620369.


Subject(s)
Nasal Sprays , Sesame Oil , Humans , Middle Aged , Female , Male , Double-Blind Method , Aged , Adult , Sesame Oil/administration & dosage , Sesame Oil/therapeutic use , Surveys and Questionnaires , Geranium , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/adverse effects , Treatment Outcome
2.
Lancet Gastroenterol Hepatol ; 8(10): 908-918, 2023 10.
Article in English | MEDLINE | ID: mdl-37541263

ABSTRACT

BACKGROUND: Malignant small bowel obstruction has a poor prognosis and is associated with multiple related symptoms. The optimal treatment approach is often unclear. We aimed to compare surgical versus non-surgical management with the aim to determine the optimal approach for managing malignant bowel obstruction. METHODS: S1316 was a pragmatic comparative effectiveness trial done within the National Cancer Trials Network at 30 hospital and cancer research centres in the USA, Mexico, Peru, and Colombia. Participants had an intra-abdominal or retroperitoneal primary cancer confirmed via pathological report and malignant bowel disease; were aged 18 years or older with a Zubrod performance status 0-2 within 1 week before admission; had a surgical indication; and treatment equipoise. Participants were randomly assigned (1:1) to surgical or non-surgical treatment using a dynamic balancing algorithm, balancing on primary tumour type. Patients who declined consent for random assignment were offered a prospective observational patient choice pathway. The primary outcome was the number of days alive and out of the hospital (good days) at 91 days. Analyses were based on intention-to-treat linear, logistic, and Cox regression models combining data from both pathways and adjusting for potential confounders. Treatment complications were assessed in all analysed patients in the study. This completed study is registered with ClinicalTrials.gov, NCT02270450. FINDINGS: From May 11, 2015, to April 27, 2020, 221 patients were enrolled (143 [65%] were female and 78 [35%] were male). There were 199 evaluable participants: 49 in the randomised pathway (24 surgery and 25 non-surgery) and 150 in the patient choice pathway (58 surgery and 92 non-surgery). No difference was seen between surgery and non-surgery for the primary outcome of good days: mean 42·6 days (SD 32·2) in the randomised surgery group, 43·9 days (29·5) in the randomised non-surgery group, 54·8 days (27·0) in the patient choice surgery group, and 52·7 days (30·7) in the patient choice non-surgery group (adjusted mean difference 2·9 additional good days in surgical versus non-surgical treatment [95% CI -5·5 to 11·3]; p=0·50). During their initial hospital stay, six participants died, five due to cancer progression (four patients from the randomised pathway, two in each treatment group, and one from the patient choice pathway, in the surgery group) and one due to malignant bowel obstruction treatment complications (patient choice pathway, non-surgery). The most common grade 3-4 malignant bowel obstruction treatment complication was anaemia (three [6%] patients in the randomised pathway, all in the surgical group, and five [3%] patients in the patient choice pathway, four in the surgical group and one in the non-surgical group). INTERPRETATION: In our study, whether patients received a surgical or non-surgical treatment approach did not influence good days during the first 91 days after registration. These findings should inform treatment decisions for patients hospitalised with malignant bowel obstruction. FUNDING: Agency for Healthcare Research and Quality and the National Cancer Institute. TRANSLATION: For the Spanish translation of the abstract see Supplementary Materials section.


Subject(s)
Intestinal Obstruction , Neoplasms , United States , Humans , Male , Female , Intestinal Obstruction/etiology , Intestinal Obstruction/surgery , Research Design , Patient Selection
3.
Cancer Med ; 12(8): 9650-9654, 2023 04.
Article in English | MEDLINE | ID: mdl-37017603

ABSTRACT

INTRODUCTION: Nasal symptoms are frequently reported by patients undergoing chemotherapy. METHODS: Eligible patients planning to receive paclitaxel, docetaxel, nab-paclitaxel, bevacizumab without a concomitant taxane, or "other" (non-taxane, non-bevacizumab) chemotherapy regimens were invited to participate in this prospective study. Patients reported nasal symptoms prior to each dose of chemotherapy. RESULTS: The percentage of patients (95% CI) who reported nasal symptoms was the same for patients who received bevacizumab or nab-paclitaxel, 82.6% (61.2%, 95.1%). There were no significant differences among the proportions of patients experiencing nasal symptoms within the paclitaxel, nab-paclitaxel, and bevacizumab cohorts. Patients in the nab-paclitaxel cohort were more likely to experience symptoms than those in the non-taxane non-bevacizumab cohort or docetaxel cohort (p = 0.001, p = 0.001). Patients in the bevacizumab cohort were more likely to experience nasal symptoms than those in the non-taxane non-bevacizumab cohort (p = 0.03). CONCLUSION: Nasal vestibulitis symptoms are common in patients receiving chemotherapy, especially those receiving paclitaxel, docetaxel, and bevacizumab. Further investigations into treatments of this symptom complex are warranted.


Subject(s)
Breast Neoplasms , Paclitaxel , Humans , Female , Docetaxel , Prospective Studies , Bevacizumab/adverse effects , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Breast Neoplasms/drug therapy
4.
J Oncol Pharm Pract ; 28(4): 842-849, 2022 Jun.
Article in English | MEDLINE | ID: mdl-33853470

ABSTRACT

INTRODUCTION: Pharmacogenetics, in hand with precision medicine in oncology, represents an opportunity to holistically tailor a patient's treatment regimen using both somatic and germline variants to improve efficacy and decrease toxicity. Colorectal cancer patients represent a population with frequent use of fluoropyrimidine and irinotecan and are an ideal opportunity for implementation of preemptive pharmacogenetics as evidence supports pharmacogenetic testing for DPYD and UGT1A1 to reduce fluoropyrimidine and irinotecan toxicities. METHODS: This was a single arm proof-of-concept study at a large community-based health system. Participants provided samples for pharmacogenetic testing via an external vendor prior to chemotherapy initiation and an oncology pharmacist was responsible for pharmacogenetic interpretation and pharmacogenetic-guided therapeutic recommendation to the treating provider. RESULTS: A total of 24 (60%) participants had a UGT1A1 variant. All participants (100%) were DPYD*1/*1. Results were available and interpreted for 29/40 (72.5%) participants prior to scheduled chemotherapy initiation (p value <0.014). Of the participants whose results were available in 5 weekdays or less (n = 23), 20 (87%) were communicated with the treating provider prior to scheduled chemotherapy administration. A total turnaround time of 5 days or less was significantly associated with PGx feasibility in a community-based oncology clinic (p = 0.03). CONCLUSIONS: In conclusion, we were able to show that implementation of preemptive pharmacogenetic testing into a community oncology clinic with results interpretation available prior to scheduled initiation of chemotherapy was feasible. As pharmacogenetic testing in oncology expands, pharmacists should be prepared to optimize supportive medication regimens as well as chemotherapy with pharmacogenetic results.


Subject(s)
Colorectal Neoplasms , Pharmacogenomic Testing , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/genetics , Feasibility Studies , Humans , Irinotecan/therapeutic use , Pharmacogenetics
5.
Support Care Cancer ; 29(11): 6253-6258, 2021 Nov.
Article in English | MEDLINE | ID: mdl-33851235

ABSTRACT

PURPOSE: To describe the natural history of nasal vestibulitis in patients receiving taxane chemotherapy, including incidence, severity, and associated symptoms. METHODS: Eligible patients with minimal or no baseline nasal symptoms were enrolled in this natural history study at initiation of a new chemotherapy regimen. Patients completed nasal symptom logs each time they received a chemotherapy dose. This manuscript reports upon the patients who received paclitaxel, docetaxel, or non-taxane non-bevacizumab chemotherapy. The proportions of patients within each cohort reporting any treatment-emergent nasal symptoms were estimated, with corresponding exact 95% confidence intervals. A cumulative incidence function was estimated within the chemotherapy cohorts to calculate the cumulative incidence rate of treatment-emergent nasal vestibulitis, treating death and disease progression as competing risks. RESULTS: Of the 81 evaluable patients, nasal symptoms were reported by 76.5% (58.8%, 89.3%) receiving paclitaxel, 54.2% (32.8%, 74.5%) receiving docetaxel, and 47.8% (26.8%, 69.4%) receiving non-taxane and non-bevacizumab chemotherapy. Of the three pairwise chemotherapy group comparisons, both the tests comparing the cumulative incidence function between the paclitaxel and non-taxane non-bevacizumab chemotherapy cohorts and between the paclitaxel and docetaxel cohorts achieved statistical significance at the 5% level with a higher incidence of treatment-emergent nasal vestibulitis in the paclitaxel cohort in both comparisons (P = 0.026 and P = 0.035, respectively). These significant differences were retained in the cumulative incidence function regression analysis controlling for age, smoking history, allergies, and asthma. Most patients in the paclitaxel cohort reported nasal symptoms as moderate or severe (56%). CONCLUSION: Patients receiving paclitaxel chemotherapy experience a high incidence of nasal symptoms.


Subject(s)
Antineoplastic Agents , Breast Neoplasms , Neoplasms , Antineoplastic Agents/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Breast Neoplasms/drug therapy , Docetaxel/adverse effects , Female , Humans , Minnesota , Neoplasms/drug therapy , Paclitaxel/adverse effects
6.
Am Soc Clin Oncol Educ Book ; 41: 1-9, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33830829

ABSTRACT

It is widely recognized that subspecialized multidisciplinary care improves neuro-oncology outcomes. Optimizing patient outcomes relies on the expertise of the treating physicians, neuroradiology and neuropathology, and supportive services familiar with common neurologic syndromes that occur after brain tumor diagnosis and treatment. Despite an increasing number of providers, patient access to specialized multidisciplinary care and clinical trials remains limited. Barriers to equitable health care exist across the United States, with marginalized communities being impacted disproportionately. Such disparity causes increased morbidity and mortality for patients from backgrounds with various elements of diversity. Limited attention to this inequity has resulted in an incomplete understanding of the spectrum of experiences that patients with neuro-oncologic diseases encounter. Clinical trials represent the highest standard and quality of care in medicine, but inclusion of under-represented and underserved groups consistently lags behind counterpart participants from majority racial and ethnic groups. Through provider education as it pertains to issues from bias and health literacy to increasing clinical trial enrollment and offering opportunities through telemedicine, opportunities for improving access to high-quality neuro-oncologic care are explored.


Subject(s)
Brain Neoplasms , Medically Underserved Area , Brain Neoplasms/diagnosis , Brain Neoplasms/epidemiology , Brain Neoplasms/therapy , Ethnicity , Humans , Racial Groups , United States/epidemiology , Vulnerable Populations
7.
Neuro Oncol ; 21(9): 1100-1117, 2019 09 06.
Article in English | MEDLINE | ID: mdl-31175826

ABSTRACT

Many factors contribute to the poor survival of malignant brain tumor patients, some of which are not easily remedied. However, one contributor to the lack of progress that may be modifiable is poor clinical trial accrual. Surveys of brain tumor patients and neuro-oncology providers suggest that clinicians do a poor job of discussing clinical trials with patients and referring patients for clinical trials. Yet, data from the Cancer Action Network of the American Cancer Society suggest that most eligible oncology patients asked to enroll on a clinical trial will agree to do so. To this end, the Society for Neuro-Oncology (SNO) in collaboration with the Response Assessment in Neuro-Oncology (RANO) Working Group, patient advocacy groups, clinical trial cooperative groups, including the Adult Brain Tumor Consortium (ABTC), and other partners are working together with the intent to double clinical trial accrual over the next 5 years. Here we describe the factors contributing to poor clinical trial accrual in neuro-oncology and offer possible solutions.


Subject(s)
Attitude to Health , Brain Neoplasms/therapy , Decision Making , Oncologists , Patient Selection , Physician-Patient Relations , Referral and Consultation , Awareness , Educational Status , Healthcare Disparities , Humans , Travel
8.
Neuro Oncol ; 14(2): 215-21, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22090453

ABSTRACT

Vorinostat, a histone deacetylase (HDAC) inhibitor, has shown evidence of single-agent activity in glioblastoma (GBM), and in preclinical studies, we have demonstrated significant synergistic cytotoxicity between HDAC inhibitors and proteasome inhibitors in GBM cell lines. We therefore conducted a phase II trial to evaluate the efficacy of vorinostat in combination with the proteasome inhibitor bortezomib in patients with recurrent GBM. Vorinostat was administered at a dose of 400 mg daily for 14 days of a 21-day cycle, and bortezomib was administered at a dose of 1.3 mg/m(2) intravenously on days 1, 4, 8, and 11 of the cycle. A total of 37 patients were treated, and treatment was well tolerated: grade 3, 4 nonhematologic toxicity occurred in 30% of patients and consisted mainly of fatigue (14%) and neuropathy (5%); grade 3, 4 hematologic toxicity occurred in 37% of patients and consisted of thrombocytopenia (30%), lymphopenia (4%), and neutropenia (4%). The trial was closed at the predetermined interim analysis, with 0 of 34 patients being progression-free at 6 months. One patient achieved a partial response according to the Macdonald criteria. The median time to progression for all patients was 1.5 months (range, 0.5-5.6 months), and median overall survival (OS) was 3.2 months. Patients who had received prior bevacizumab therapy had a shorter time to progression and OS, compared with those who had not. On the basis of the results of this phase II study, further evaluation of the vorinostat-bortezomib combination in GBM patients in this dose and schedule is not recommended.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Boronic Acids/therapeutic use , Brain Neoplasms/drug therapy , Glioblastoma/drug therapy , Hydroxamic Acids/therapeutic use , Pyrazines/therapeutic use , Adult , Aged , Aged, 80 and over , Boronic Acids/administration & dosage , Bortezomib , Disease Progression , Female , Glioblastoma/mortality , Humans , Hydroxamic Acids/administration & dosage , Male , Middle Aged , Pyrazines/administration & dosage , Survival Analysis , Vorinostat
9.
Cancer Res ; 68(15): 6145-53, 2008 Aug 01.
Article in English | MEDLINE | ID: mdl-18676837

ABSTRACT

AZD6244 (ARRY 142886) is a potent and selective mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase (MEK) inhibitor currently in early clinical trials. We examined the activity of AZD6244 in a panel of non-small cell lung cancer and a panel of cell lines representing many cancer types using in vitro growth assays. AZD6244 induced G(0)-G(1) cell cycle arrest in sensitive cell lines that primarily included cells containing the BRAF V600E mutation. In these cells, G(0)-G(1) arrest is accompanied by the up-regulation of the cell cycle inhibitors p21(WAF1) and p27(Kip1) and down-regulation of cyclin D1. In the majority of cell lines tested, including those with K-ras or non-V600E BRAF mutations, AZD6244 induced the accumulation of phospho-MEK, an effect not observed in the most sensitive BRAF V600E-containing cells. Accumulation of phospho-MEK in non-V600E-containing cell lines is due to abrogation of negative feedback pathways. BRAF V600E disrupts negative feedback signaling, which results in enhanced baseline phospho-MEK expression. Exogenous expression of BRAF V600E disrupts feedback inhibition but does not sensitize cells to AZD6244. Specific suppression of endogenous BRAF V600E does not confer resistance to AZD6244 but enhances sensitivity to AZD6244. Thus, our findings show that BRAF V600E marks cells with an in vitro requirement for MAPK signaling to support proliferation. These cells are exquisitely sensitive to AZD6244 (IC(50), <100 nmol/L), have high baseline levels of phospho-MEK, and lack feedback inhibition between ERK and Raf. These data suggest an approach to identifying cells that may be sensitive to AZD6244 and other MEK inhibitors.


Subject(s)
Benzimidazoles/pharmacology , Extracellular Signal-Regulated MAP Kinases/metabolism , Proto-Oncogene Proteins B-raf/physiology , raf Kinases/metabolism , Base Sequence , Cell Line, Tumor , Cyclin-Dependent Kinase Inhibitor p21/metabolism , Cyclin-Dependent Kinase Inhibitor p27 , DNA Primers , Down-Regulation , Humans , Intracellular Signaling Peptides and Proteins/metabolism , Mutation , Polymerase Chain Reaction , Proto-Oncogene Proteins B-raf/genetics
10.
Neuro Oncol ; 10(3): 309-19, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18445700

ABSTRACT

The effects of combining histone deacetylase (HDAC) inhibitors and proteasome inhibitors were evaluated in both established glioblastoma multiforme (GBM) cell lines and short-term cultures derived from the Mayo Clinic xenograft GBM panel. Coexposure of LBH589 and bortezomib at minimally toxic doses of either drug alone resulted in a striking induction of apoptosis in established U251, U87, and D37 GBM cell lines, as well as in GBM8, GBM10, GBM12, GBM14, and GBM56 short-term cultured cell lines. Synergism of apoptosis induction was also observed in U251 cells when coexposing cells to other HDAC inhibitors, including LAQ824 and trichostatin A, with the proteasome inhibitor MG132, thus demonstrating a class effect. In U251 cells, bortezomib alone or in combination with LBH589 decreased Raf-1 levels and suppressed Akt and Erk activation. LBH589 or bortezomib alone increased expression of the cell cycle regulators p21 and p27. Additionally, the combination, but not the individual agents, markedly enhanced JNK activation. Synergistic induction of apoptosis after exposure to LBH589 and bortezomib was partially mediated by Bax translocation from the cytosol to the mitochondria resulting from Bax conformational changes. Bax translocation precedes cytochrome c release and apoptosis, and selective down-regulation of Bax using siRNA significantly mitigates the cytotoxicity of LBH589 and bortezomib. This combination regimen warrants further preclinical and possible clinical study for glioma patients.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacology , Brain Neoplasms/drug therapy , Enzyme Inhibitors/administration & dosage , Glioma/drug therapy , Mitochondria/metabolism , bcl-2-Associated X Protein/metabolism , Apoptosis/drug effects , Blotting, Western , Boronic Acids/administration & dosage , Bortezomib , Cell Line, Tumor , Cell Proliferation/drug effects , Drug Synergism , Electrophoresis, Polyacrylamide Gel , Histone Deacetylase Inhibitors , Humans , Hydroxamic Acids/administration & dosage , Indoles , Panobinostat , Proteasome Inhibitors , Protein Transport/drug effects , Pyrazines/administration & dosage , RNA, Small Interfering , bcl-2-Associated X Protein/drug effects
11.
Clin Cancer Res ; 14(2): 342-6, 2008 Jan 15.
Article in English | MEDLINE | ID: mdl-18223206

ABSTRACT

The identification of intracellular signaling cascades important for the growth and survival of cancer cells has led to the development of targeted cancer therapeutics aimed at blocking these signals. The mitogen-activated protein kinase (MAPK) pathway has a well-defined role in cancer biology and has been an important target in the development of targeted therapies. Recently, several small-molecule inhibitors of MAPK/extracellular signal-regulated kinase kinase (MEK), a key intermediary of MAPK signaling, have been developed and are currently being tested in clinical trials. Herein, we review the MAPK pathway, the development of small-molecule MEK inhibitors, and the results obtained to date with MEK inhibitors in human cancer trials.


Subject(s)
Antineoplastic Agents/therapeutic use , Enzyme Inhibitors/therapeutic use , MAP Kinase Signaling System/drug effects , Mitogen-Activated Protein Kinases/metabolism , Neoplasms/drug therapy , Antineoplastic Agents/pharmacology , Enzyme Inhibitors/pharmacology , Extracellular Signal-Regulated MAP Kinases/metabolism , Humans , Neoplasms/enzymology , Small Molecule Libraries/pharmacology , raf Kinases/metabolism , ras Proteins/metabolism
13.
Clin Cancer Res ; 13(4): 1140-8, 2007 Feb 15.
Article in English | MEDLINE | ID: mdl-17317822

ABSTRACT

PURPOSE: To evaluate the effects of combining the multiple receptor tyrosine kinase inhibitor AEE788 and histone deacetylase (HDAC) inhibitors on cytotoxicity in a broad spectrum of cancer cell lines, including cisplatin-resistant ovarian adenocarcinoma cells. EXPERIMENTAL DESIGN: Multiple cancer cell lines were treated in vitro using AEE788 and HDAC inhibitors (LBH589, LAQ824, and trichostatin A), either alone or in combination. Effects on cytotoxicity were determined by growth and morphologic assays. Effects of the combination on cell signaling pathways were determined by Western blotting, and the results were confirmed using pathway-specific inhibitors and transfection of constitutively active proteins. RESULTS: Cell treatment with AEE788 and HDAC inhibitors (LBH589, LAQ824, and trichostatin A) in combination resulted in synergistic induction of apoptosis in non-small cell lung cancer (MV522, A549), ovarian cancer (SKOV-3), and leukemia (K562, Jurkat, and ML-1) cells and in OV202hp cisplatin-resistant human ovarian cancer cells. AEE788 alone or in combination with LBH589 inactivated mitogen-activated protein kinase (MAPK) and Akt cascades. Inhibition of either MAPK and/or Akt enhanced LBH589-induced apoptosis. In contrast, constitutively active MAPK or Akt attenuated LBH589 or LBH589 + AEE788-induced apoptosis. Increased apoptosis was correlated with enhanced reactive oxygen species (ROS) generation. The free radical scavenger N-acetyl-l-cysteine not only substantially suppressed the ROS accumulation but also blocked the induction of apoptosis mediated by cotreatment with AEE788 and LBH589. CONCLUSION: Collectively, these results show that MAPK and Akt inactivation along with ROS generation contribute to the synergistic cytotoxicity of the combination of AEE788 and HDAC inhibitors in a variety of human cancer cell types. This combination regimen warrants further preclinical and possible clinical study for a broad spectrum of cancers.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacology , Histone Deacetylase Inhibitors , Mitogen-Activated Protein Kinase Kinases/antagonists & inhibitors , Oncogene Protein v-akt/antagonists & inhibitors , Purines/pharmacology , Reactive Oxygen Species/metabolism , Apoptosis/drug effects , Cell Line, Tumor , Drug Synergism , Humans , Hydroxamic Acids/administration & dosage , Hydroxamic Acids/pharmacology , Indoles , Jurkat Cells , K562 Cells , Leukemia/drug therapy , Leukemia/enzymology , Leukemia/metabolism , MAP Kinase Signaling System/drug effects , Mitogen-Activated Protein Kinase Kinases/metabolism , Oncogene Protein v-akt/metabolism , Panobinostat , Purines/administration & dosage
14.
Mol Cancer Ther ; 5(9): 2378-87, 2006 Sep.
Article in English | MEDLINE | ID: mdl-16985072

ABSTRACT

This study was undertaken to characterize preclinical cytotoxic interactions for human malignancies between the multikinase inhibitor sorafenib (BAY 43-9006) and proteasome inhibitors bortezomib or MG132. Multiple tumor cell lines of varying histiotypes, including A549 (lung adenocarcinoma), 786-O (renal cell carcinoma), HeLa (cervical carcinoma), MDA-MB-231 (breast), K562 (chronic myelogenous leukemia), Jurkat (acute T-cell leukemia), MEC-2 (B-chronic lymphocytic leukemia), and U251 and D37 (glioma), as well as cells derived from primary human glioma tumors that are likely a more clinically relevant model were treated with sorafenib or bortezomib alone or in combination. Sorafenib and bortezomib synergistically induced a marked increase in mitochondrial injury and apoptosis, reflected by cytochrome c release, caspase-3 cleavage, and poly(ADP-ribose) polymerase degradation in a broad range of solid tumor and leukemia cell lines. These findings were accompanied by several biochemical changes, including decreased phosphorylation of vascular endothelial growth factor receptor-2, platelet-derived growth factor receptor-beta, and Akt and increased phosphorylation of stress-related c-Jun NH2-terminal kinase (JNK). Inhibition of Akt was required for synergism, as a constitutively active Akt protected cells against apoptosis induced by the combination. Alternatively, the JNK inhibitor SP600125 could also protect cells from apoptosis induced by the combination, indicating that both inhibition of Akt and activation of JNK were required for the synergism. These findings show that sorafenib interacts synergistically with bortezomib to induce apoptosis in a broad spectrum of neoplastic cell lines and show an important role for the Akt and JNK pathways in mediating synergism. Further clinical development of this combination seems warranted.


Subject(s)
Apoptosis/drug effects , Benzenesulfonates/pharmacology , Boronic Acids/pharmacology , JNK Mitogen-Activated Protein Kinases/metabolism , Oncogene Protein v-akt/metabolism , Protease Inhibitors/pharmacology , Proteasome Inhibitors , Pyrazines/pharmacology , Pyridines/pharmacology , Antineoplastic Agents/pharmacology , Bortezomib , Cell Line, Tumor , Drug Synergism , Humans , JNK Mitogen-Activated Protein Kinases/genetics , Jurkat Cells , K562 Cells , MAP Kinase Signaling System/drug effects , Niacinamide/analogs & derivatives , Phenylurea Compounds , Proteasome Endopeptidase Complex/metabolism , Sorafenib
16.
Biochim Biophys Acta ; 1756(2): 127-44, 2005 Nov 25.
Article in English | MEDLINE | ID: mdl-16139957

ABSTRACT

The central role K-, H- and N-Ras play in regulating diverse cellular pathways important for cell growth, differentiation and survival is well established. Dysregulation of Ras proteins by activating mutations, overexpression or upstream activation is common in human tumors. Of the Ras proteins, K-ras is the most frequently mutated and is therefore an attractive target for cancer therapy. The complexity of K-ras signaling presents many opportunities for therapeutic targeting. A number of different approaches aimed at abrogating K-ras activity have been explored in clinical trials. Several of the therapeutic agents tested have demonstrated clinical activity, supporting ongoing development of K-ras targeted therapies. However, many of the agents currently being evaluated have multiple targets and their antitumor effects may not be due to K-Ras inhibition. To date, no selective, specific inhibitor of K-ras is available for routine clinical use. In this review, we will summarize the structure and function of K-ras with attention to its role in tumorigenesis and discuss the successes and failures of the various strategies designed to therapeutically target this important oncogene.


Subject(s)
Genes, ras , Neoplasms/genetics , Gene Expression Regulation, Neoplastic , Genetic Therapy/methods , Humans , Neoplasms/therapy , RNA Interference , ras Proteins/genetics
17.
Differentiation ; 71(3): 217-27, 2003 Apr.
Article in English | MEDLINE | ID: mdl-12694204

ABSTRACT

Skeletal muscle differentiation is characterized by withdrawal from the cell cycle, expression of muscle specific genes, fusion into multinucleated cells, and assembly of the contractile apparatus. Although many of the key regulatory elements have been identified, the factors that initiate the differentiation process are not well understood. The calcium-dependent phosphatase calcineurin plays an important regulatory role early in myogenesis, but the downstream effectors of calcineurin in differentiation are not known. Here, we show that calcium and calcineurin regulate expression of the myogenin gene at the level of transcription. The myogenin promoter contains two essential elements; an E-box and an A/T rich element that bind MRF and MEF2 transcription factors, respectively. Both of these elements are responsive to calcium and calcineurin. In differentiating myoblasts, MyoD is the major MRF protein that binds to the myogenin promoter E-box. Calcineurin activates MyoD indirectly by decreasing the expression of the Id inhibitory proteins, probably by down-regulating Egr-1 expression, an upstream activator of Id transcription. These results demonstrate that calcineurin regulates skeletal muscle differentiation by activating MEF2 and MyoD transcription factors leading to the induction of myogenin expression.


Subject(s)
Calcineurin/pharmacology , Cell Differentiation/drug effects , DNA-Binding Proteins/genetics , Muscle, Skeletal/cytology , MyoD Protein/genetics , Myogenin/genetics , Transcription Factors/genetics , Animals , Base Sequence , Cell Differentiation/physiology , Cell Division , Cells, Cultured , DNA Primers , Dactinomycin/pharmacology , MEF2 Transcription Factors , Mice , Mice, Inbred BALB C , Muscle, Skeletal/drug effects , Muscle, Skeletal/physiology , Myogenic Regulatory Factors , Promoter Regions, Genetic , RNA, Messenger/drug effects , RNA, Messenger/genetics , Reverse Transcriptase Polymerase Chain Reaction , Transcription, Genetic/drug effects
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