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1.
Oncologist ; 29(6): 534-542, 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38417095

ABSTRACT

BACKGROUND: A recent real-world study observed that 24% of patients with advanced non-small cell lung cancer (aNSCLC) with actionable driver oncogenes (ADOs) initiated nontargeted therapies before biomarker test results became available. This study assessed the clinical impact of the timing of first-line (1L) targeted therapies (TTs) in aNSCLC. MATERIALS AND METHODS: This retrospective analysis of a nationwide electronic health record-derived deidentified database included patients aged ≥18 years diagnosed with aNSCLC with ADOs (ALK, BRAF, EGFR, RET, MET, ROS-1, and NTRK) from January 1, 2015, to October 18, 2022, by biomarker testing within 90 days after advanced diagnosis and received 1L treatment. Cohorts were defined by treatment patterns ≤42 days after test results: "Upfront TT" received 1L TT ≤42 days; "Switchers" initiated 1L non-TT before or after testing but switched to TT ≤42 days; and "Non-switchers" initiated non-TT before or after testing and did not switch at any time. Adjusted multivariate Cox regression evaluated real-world progression-free survival, real-world time to next treatment or death, and real-world overall survival. RESULTS: A total of 3540 patients met the study criteria; 78% were treated in a community setting, and 50% underwent next-generation sequencing (NGS). There was no significant difference in outcomes between Switchers and Upfront TT; inferior outcomes were observed in Non-switchers versus Upfront TT. CONCLUSION: Our findings demonstrated improved outcomes with upfront 1L TT versus non-TT in patients with aNSCLC with ADOs and observed timely switching to TT after biomarker test result had similar outcomes to Upfront TT. Opportunities remain to improve the use of NGS for early ADO identification and determination of 1L TT.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Molecular Targeted Therapy , Oncogenes , Humans , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/pathology , Carcinoma, Non-Small-Cell Lung/mortality , Female , Male , Lung Neoplasms/drug therapy , Lung Neoplasms/pathology , Lung Neoplasms/genetics , Lung Neoplasms/mortality , Middle Aged , Retrospective Studies , Molecular Targeted Therapy/methods , Aged , Adult , Biomarkers, Tumor/genetics , Aged, 80 and over
2.
J Clin Oncol ; 42(3): 258-265, 2024 Jan 20.
Article in English | MEDLINE | ID: mdl-37793085

ABSTRACT

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.The MyPathway multiple-basket study (ClinicalTrials.gov identifier: NCT02091141) is evaluating targeted therapies in nonindicated tumors with relevant molecular alterations. We assessed pertuzumab + trastuzumab in a tissue-agnostic cohort of adult patients with human epidermal growth factor receptor 2 (HER2)-amplified and/or -overexpressed and/or -mutated solid tumors. The primary end point was objective response rate (ORR); secondary end points included survival and safety. At data cutoff (March 2022), 346 patients with HER2 amplification and/or overexpression with/without HER2 mutations (n = 263), or HER2 mutations alone (n = 83) had been treated. Patients with HER2 amplification and/or overexpression had an ORR of 25.9% (68/263, 95% CI, 20.7 to 31.6), including five complete responses (urothelial [n = 2], salivary gland [n = 2], and colon [n = 1] cancers). Activity was higher in those with wild-type (ORR, 28.1%) versus mutated KRAS (ORR, 7.1%). Among patients with HER2 amplification, ORR was numerically higher in patients with immunohistochemistry (IHC) 3+ (41.0%; 32/78) or 2+ (21.9%; 7/32), versus 1+ (8.3%; 1/12) or no expression (0%; 0/20). In patients with HER2 mutations alone, ORR was 6.0% (5/83, 95% CI, 2.0 to 13.5). Pertuzumab + trastuzumab showed activity in various HER2-amplified and/or -overexpressed tumors with wild-type KRAS, with the range of activity dependent on tumor type, but had limited activity in the context of KRAS mutations, HER2 mutations alone, or 0-1+ HER2 expression.


Subject(s)
Antibodies, Monoclonal, Humanized , Neoplasms , Proto-Oncogene Proteins p21(ras) , Adult , Humans , Trastuzumab/adverse effects , Proto-Oncogene Proteins p21(ras)/metabolism , Receptor, ErbB-2/metabolism , Neoplasms/drug therapy , Neoplasms/genetics , Neoplasms/pathology , Antineoplastic Combined Chemotherapy Protocols/adverse effects
3.
Future Oncol ; 19(20): 1397-1414, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37318757

ABSTRACT

Aim: Biomarker testing detects actionable driver mutations to inform first-line treatment in advanced non-small-cell lung cancer (aNSCLC) and metastatic colorectal cancer (mCRC). This study evaluated biomarker testing in a nationwide database (NAT) versus the OneOncology (OneOnc) community network. Patients & methods: Patients with aNSCLC or mCRC with ≥1 biomarker test in a de-identified electronic health record-derived database were evaluated. OneOnc oncologists were surveyed. Results: Biomarker testing rates were high and comparable between OneOnc and NAT; next-generation sequencing (NGS) rates were higher at OneOnc. Patients with NGS versus other biomarker testing were more likely to receive targeted treatment. Operational challenges and insufficient tissue were barriers to NGS testing. Conclusion: Community cancer centers delivered personalized healthcare through biomarker testing.


What is this article about? Cancer therapies often work better in certain subgroups of patients. Tumors may have characteristics that can predict which therapies may be more likely to work. These cancer biomarkers may be identified by special testing, such as next-generation sequencing (NGS). If a biomarker is detected, the patient can potentially be treated with medicine that targets that biomarker. This study looked at biomarker testing of lung and colon cancers in two community cancer practices (OneOncology [OneOnc] and nationwide database [NAT]). What were the results? The biomarker testing rates were high (≥81%) and similar between OneOnc and NAT. NGS testing rates were higher at OneOnc than at NAT (58 vs 49% for non-small-cell lung cancer, 55 vs 42% for metastatic colorectal cancer [mCRC]), suggesting the success of OneOnc's networkwide educational, pathway and operational programs. NGS testing was lower in community practices due to operational challenges and insufficient tissue collection. Patients who had NGS versus other biomarker testing were more likely to receive treatment specifically for that biomarker. However, some patients started treatment before their biomarker results were reported, usually because of their disease and a long wait time for biomarker test results. What do the results of the study mean? Community cancer centers can treat patients with targeted medicine based on biomarker testing results. There are opportunities to increase the number of patients getting NGS testing, shorten turnaround times and reduce the number of patients who start treatment before getting their biomarker test results.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Colorectal Neoplasms , Lung Neoplasms , Humans , United States/epidemiology , Carcinoma, Non-Small-Cell Lung/diagnosis , Carcinoma, Non-Small-Cell Lung/epidemiology , Carcinoma, Non-Small-Cell Lung/genetics , Lung Neoplasms/diagnosis , Lung Neoplasms/genetics , Lung Neoplasms/therapy , Community Networks , Biomarkers, Tumor/genetics , Colorectal Neoplasms/diagnosis , Colorectal Neoplasms/genetics , Colorectal Neoplasms/therapy , High-Throughput Nucleotide Sequencing , Mutation
4.
Breast Cancer Res ; 19(1): 16, 2017 02 09.
Article in English | MEDLINE | ID: mdl-28183321

ABSTRACT

BACKGROUND: NeoSphere showed significantly higher pathologic complete response (pCR) with neoadjuvant pertuzumab, trastuzumab, and docetaxel compared with trastuzumab plus docetaxel, pertuzumab plus trastuzumab, or pertuzumab plus docetaxel. We assessed associations between human epidermal growth factor receptor 2 (HER2) pathway-related biomarkers and clinical outcome in response to these regimens. METHODS: Tumor, serum, and whole blood samples were collected at baseline and post neoadjuvant treatment before surgery. Associations between biomarkers and pCR, and between biomarkers and clinical variables were assessed in the overall and estrogen receptor (ER)-positive and ER-negative populations. Changes in serum marker levels between baseline and post-neoadjuvant treatment were examined. RESULTS: No markers were associated with pCR across all groups; however, significant associations were observed for two markers in individual groups. High HER2 was significantly associated with higher pCR rates (P = 0.001) and a significant treatment interaction (P = 0.0236) with pertuzumab, trastuzumab, and docetaxel (odds ratio 2.07, P = 0.01). Low serum transforming growth factor alpha (TGFα) was associated with higher pCR rates with pertuzumab plus trastuzumab (P = 0.04) without a significant treatment interaction. Presence of truncated HER2 did not affect pCR. A non-significant decreased pCR benefit was observed consistently across groups in patients with mutated PIK3CA while the treatment benefit from pertuzumab was maintained when comparing the trastuzumab plus docetaxel and pertuzumab, trastuzumab, and docetaxel groups. Notably, PIK3CA exon 9 mutations were associated with residual disease (pooled groups), which was not found for exon 20 mutations. Serum HER2 extracellular domain levels were significantly increased between baseline and post-neoadjuvant treatment in the non-trastuzumab-treated group, and decreased in the trastuzumab-containing groups (likely due to trastuzumab's mechanism of action). Differences in biomarker profiles according to ER status were observed. CONCLUSIONS: The observed associations of HER2 protein levels with sensitivity to pertuzumab, and of PIK3CA exon 9 mutation to lack of sensitivity to HER2-targeted monoclonal antibody treatment, warrant further investigation. Previously reported findings of truncated forms of HER2 as resistance markers to HER2-targeted treatment could not be confirmed in NeoSphere. Conventional HER2 assessment should continue and HER2 remains the only biomarker suitable for patient selection in this population. TRIAL REGISTRATION: Clinicaltrials.gov, NCT00545688 . Registered on 16 October 2007.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Biomarkers , Breast Neoplasms/drug therapy , Breast Neoplasms/metabolism , Receptor, ErbB-2/metabolism , Antibodies, Monoclonal, Humanized/administration & dosage , Biomarkers, Tumor , Breast Neoplasms/genetics , Docetaxel , Female , Humans , Immunohistochemistry , Mutation , Neoadjuvant Therapy , Taxoids/administration & dosage , Trastuzumab/administration & dosage , Treatment Outcome
5.
J Clin Oncol ; 30(14): 1594-600, 2012 May 10.
Article in English | MEDLINE | ID: mdl-22393084

ABSTRACT

PURPOSE: The combination of pertuzumab and trastuzumab resulted in a clinical benefit rate (CBR) of 50% in patients with human epidermal growth factor receptor 2 (HER2) -positive breast cancer whose disease progressed during prior trastuzumab-based therapy. To define whether this previously observed encouraging activity was a result of the combination of pertuzumab and trastuzumab or of pertuzumab alone, we recruited a third cohort of patients who received pertuzumab without trastuzumab. We then investigated the impact of reintroducing trastuzumab to patients whose disease progressed on pertuzumab monotherapy. PATIENTS AND METHODS: Twenty-nine patients with HER2-positive breast cancer whose disease progressed during prior trastuzumab-based therapy received pertuzumab (840 mg loading dose, then 420 mg every 3 weeks) until progressive disease or unacceptable toxicity. Seventeen patients with disease progression continued to receive pertuzumab (at the same dose), with the addition of trastuzumab (4 mg/kg loading dose and then 2 mg/kg weekly or 8 mg/kg loading dose and then 6 mg/kg every 3 weeks). RESULTS: All 29 patients enrolled for pertuzumab monotherapy experienced disease progression. The objective response rate (ORR) and CBR were 3.4% and 10.3%, respectively, during pertuzumab monotherapy. With the addition of trastuzumab, the ORR and CBR were 17.6% and 41.2%, respectively. Progression-free survival was longer with combination therapy than pertuzumab monotherapy (17.4 v 7.1 weeks, respectively). Treatment was well tolerated with minimal cardiac dysfunction. CONCLUSION: Although pertuzumab has some activity in patients with HER2-positive breast cancer that progressed during therapy with trastuzumab, the combination of pertuzumab and trastuzumab seems to be more active than monotherapy.


Subject(s)
Antibodies, Monoclonal, Humanized/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Breast Neoplasms/drug therapy , Breast Neoplasms/metabolism , Receptor, ErbB-2/metabolism , Adult , Age Factors , Aged , Antibodies, Monoclonal, Humanized/adverse effects , Breast Neoplasms/mortality , Breast Neoplasms/pathology , Disease Progression , Disease-Free Survival , Dose-Response Relationship, Drug , Drug Administration Schedule , Female , Humans , Maximum Tolerated Dose , Middle Aged , Neoplasm Invasiveness/pathology , Neoplasm Staging , Patient Selection , Prognosis , Prospective Studies , Risk Assessment , Survival Analysis , Trastuzumab , Treatment Outcome
6.
Lancet Oncol ; 13(1): 25-32, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22153890

ABSTRACT

BACKGROUND: Studies with pertuzumab, a novel anti-HER2 antibody, show improved efficacy when combined with the established HER2-directed antibody trastuzumab in breast cancer therapy. We investigated the combination of pertuzumab or trastuzumab, or both, with docetaxel and the combination of pertuzumab and trastuzumab without chemotherapy in the neoadjuvant setting. METHODS: In this multicentre, open-label, phase 2 study, treatment-naive women with HER2-positive breast cancer were randomly assigned (1:1:1:1) centrally and stratified by operable, locally advanced, and inflammatory breast cancer, and by hormone receptor expression to receive four neoadjuvant cycles of: trastuzumab (8 mg/kg loading dose, followed by 6 mg/kg every 3 weeks) plus docetaxel (75 mg/m(2), escalating, if tolerated, to 100 mg/m(2) every 3 weeks; group A) or pertuzumab (loading dose 840 mg, followed by 420 mg every 3 weeks) and trastuzumab plus docetaxel (group B) or pertuzumab and trastuzumab (group C) or pertuzumab plus docetaxel (group D). The primary endpoint, examined in the intention-to-treat population, was pathological complete response in the breast. Neither patients nor investigators were masked to treatment. This study is registered with ClinicalTrials.gov, number NCT00545688. FINDINGS: Of 417 eligible patients, 107 were randomly assigned to group A, 107 to group B, 107 to group C, and 96 to group D. Patients given pertuzumab and trastuzumab plus docetaxel (group B) had a significantly improved pathological complete response rate (49 of 107 patients; 45·8% [95% CI 36·1-55·7]) compared with those given trastuzumab plus docetaxel (group A; 31 of 107; 29·0% [20·6-38·5]; p=0·0141). 23 of 96 (24·0% [15·8-33·7]) women given pertuzumab plus docetaxel (group D) had a pathological complete response, as did 18 of 107 (16·8% [10·3-25·3]) given pertuzumab and trastuzumab (group C). The most common adverse events of grade 3 or higher were neutropenia (61 of 107 women in group A, 48 of 107 in group B, one of 108 in group C, and 52 of 94 in group D), febrile neutropenia (eight, nine, none, and seven, respectively), and leucopenia (13, five, none, and seven, respectively). The number of serious adverse events was similar in groups A, B, and D (15-20 serious adverse events per group in 10-17% of patients) but lower in group C (four serious adverse events in 4% of patients). INTERPRETATION: Patients given pertuzumab and trastuzumab plus docetaxel (group B) had a significantly improved pathological complete response rate compared with those given trastuzumab plus docetaxel, without substantial differences in tolerability. Pertuzumab and trastuzumab without chemotherapy eradicated tumours in a proportion of women and showed a favourable safety profile. These findings justify further exploration in adjuvant trials and support the neoadjuvant approach for accelerating drug assessment in early breast cancer. FUNDING: F Hoffmann-La Roche.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Biomarkers, Tumor/metabolism , Breast Neoplasms/drug therapy , Inflammation/pathology , Receptor, ErbB-2/metabolism , Adult , Aged , Aged, 80 and over , Antibodies, Monoclonal, Humanized/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Asia , Biomarkers, Tumor/antagonists & inhibitors , Brazil , Breast Neoplasms/enzymology , Breast Neoplasms/pathology , Breast Neoplasms/surgery , Canada , Chemotherapy, Adjuvant , Docetaxel , Europe , Female , Humans , Mastectomy , Middle Aged , Neoadjuvant Therapy , Neoplasm Invasiveness , Protein Kinase Inhibitors/administration & dosage , Receptor, ErbB-2/antagonists & inhibitors , Taxoids/administration & dosage , Time Factors , Trastuzumab , Treatment Outcome , Young Adult
7.
Proc Natl Acad Sci U S A ; 105(7): 2427-32, 2008 Feb 19.
Article in English | MEDLINE | ID: mdl-18250332

ABSTRACT

Imbalance of signals that control cell survival and death results in pathologies, including cancer and neurodegeneration. Two pathways that are integral to setting the balance between cell survival and cell death are controlled by lipid-activated protein kinase B (PKB)/Akt and Ca(2+). PKB elicits its effects through the phosphorylation and inactivation of proapoptotic factors. Ca(2+) stimulates many prodeath pathways, among which is mitochondrial permeability transition. We identified Ca(2+) release through inositol 1,4,5-trisphosphate receptor (InsP(3)R) intracellular channels as a prosurvival target of PKB. We demonstrated that in response to survival signals, PKB interacts with and phosphorylates InsP(3)Rs, significantly reducing their Ca(2+) release activity. Moreover, phosphorylation of InsP(3)Rs by PKB reduced cellular sensitivity to apoptotic stimuli through a mechanism that involved diminished Ca(2+) flux from the endoplasmic reticulum to the mitochondria. In glioblastoma cells that exhibit hyperactive PKB, the same prosurvival effect of PKB on InsP(3)R was found to be responsible for the insensitivity of these cells to apoptotic stimuli. We propose that PKB-mediated abolition of InsP(3)-induced Ca(2+) release may afford tumor cells a survival advantage.


Subject(s)
Apoptosis , Calcium/metabolism , Inositol 1,4,5-Trisphosphate Receptors/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Animals , Apoptosis/drug effects , Calcium/agonists , Cell Line , Chlorocebus aethiops , Glioblastoma/metabolism , Glioblastoma/pathology , Humans , Inositol 1,4,5-Trisphosphate Receptors/genetics , Phosphorylation , Serine/genetics , Serine/metabolism
8.
J Vasc Res ; 44(6): 495-503, 2007.
Article in English | MEDLINE | ID: mdl-17657165

ABSTRACT

Endothelin-1 (ET1) is an endogenous vasoconstrictor released by the vascular system to regulate the contractility of vascular smooth muscle cells (VSMC). It is implicated in the pathogenesis of hypertension and diabetic vasculopathy. In rabbit inferior vena cava (IVC), 10 nM ET1 induces tonic contraction mainly via type A endothelin receptor activation. Using confocal imaging of Fluo-3 loaded in thein situ VSMC within the intact IVC, we found that ET1 elicited [Ca2+]i oscillations with an average frequency of 0.31 +/- 0.01 Hz. These [Ca2+]i oscillations occurred as repetitive Ca2+ waves traveling along the longitudinal axis of the cells with an average velocity of 29 +/- 3 microm/s. The Ca2+ waves were not synchronized between neighboring VSMC nor were they propagated between them. Nifedipine (10 microM) inhibited the tonic contraction by 27.0 +/- 5.0% while SKF96365 (50 microM) abolished the remaining contraction. In a parallel Ca2+ study, nifedipine reduced the frequency of the oscillations to 0.22 +/- 0.01 Hz while SKF96365 abolished the remaining [Ca2+]i oscillations. Subsequent application of 25 mM caffeine elicited no further Ca2+ signal. Thus, we conclude that ET1 stimulates tonic contraction in the rabbit IVC by inducing [Ca2+]i oscillations and that stimulated Ca2+ entry through both the L-type voltage-gated Ca2+ channels and a nifedipine-resistant and SKF96365-sensitive pathway is crucial for the maintenance of [Ca2+]i oscillations and tonic contraction.


Subject(s)
Calcium Channels/metabolism , Calcium Signaling , Endothelin-1/metabolism , Muscle, Smooth, Vascular/metabolism , Receptor, Endothelin A/metabolism , Vasoconstriction , Vasoconstrictor Agents/metabolism , Animals , Calcium Channel Blockers/pharmacology , Calcium Channels/drug effects , Calcium Channels, L-Type/metabolism , Calcium Signaling/drug effects , Endothelin-1/pharmacology , Female , Imidazoles/pharmacology , In Vitro Techniques , Microscopy, Confocal , Muscle, Smooth, Vascular/drug effects , Nifedipine/pharmacology , Oligopeptides/pharmacology , Peptides, Cyclic/pharmacology , Piperidines/pharmacology , Rabbits , Receptor, Endothelin A/drug effects , Time Factors , Vasoconstriction/drug effects , Vasoconstrictor Agents/pharmacology , Vena Cava, Inferior/metabolism
9.
Eur J Pharmacol ; 505(1-3): 19-29, 2004 Nov 28.
Article in English | MEDLINE | ID: mdl-15556133

ABSTRACT

Basal calcium leak into smooth muscle was identified 30 years ago yet remains poorly understood. We characterized this leak measuring 45Ca2+ uptake into cultured rat aortic smooth muscle cells. Wash solution (0 degrees C) containing lanthanum (3 mM) removed extracellular tracer and increased cellular 45Ca2+ retention more effectively than EGTA (0.2 mM). Basal Ca2+ entry was 1.45 x 10(9) Ca2+ x cell(-1) x min(-1). This translated to approximately 250 micromol(-1) x min(-1) given cell volumes of 4-15 pl as determined by 3-D image reconstruction. Gadolinium (100 microM) blocked 80% of the leak and exhibited a biphasic concentration-response relation (IC50s=1 microM and 2 mM). Organic ion channel blockers also inhibited approximately 80% of the leak; 45% by nifedipine (10 microM), 7% was exclusively blocked by SKF 96365 (1-[b-[3-(4-Methoxyphenyl)propoxy]-4-methoxyphenethyl]-1H-imidazole) (50 microM) and 23% was exclusively sensitive to 2-aminoethoxy-diphenylborate (2-APB, 75 microM). Reverse transcriptase polymerase chain reaction revealed TrpC1, 4 and 6 mRNA, and we propose that 2-APB may selectively block TrpC4-containing channels. We conclude that basal Ca2+ entry is mainly due to a basal open probability of excitable Ca2+ -channels.


Subject(s)
Calcium/metabolism , Muscle, Smooth, Vascular/metabolism , Animals , Boron Compounds/pharmacology , Calcium/pharmacokinetics , Calcium Channel Blockers/pharmacology , Calcium Channels/genetics , Calcium Radioisotopes , Dose-Response Relationship, Drug , Egtazic Acid/pharmacology , Gadolinium/pharmacology , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , Imidazoles/pharmacology , Lanthanum/pharmacology , Male , Membrane Proteins/genetics , Microscopy, Confocal , Muscle, Smooth, Vascular/cytology , Muscle, Smooth, Vascular/drug effects , Nerve Tissue Proteins/genetics , Nifedipine/pharmacology , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Rats, Inbred WKY , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Synaptosomal-Associated Protein 25 , TRPC Cation Channels
10.
J Vasc Res ; 40(6): 520-30, 2003.
Article in English | MEDLINE | ID: mdl-14646372

ABSTRACT

The vasomotor properties of isolated aortae and mesenteric arteries of insulin-resistant ob/ob and 57CBL/6J mice were compared in organ bath studies. Vessels from ob/ob mice were more sensitive to phenylephrine. Pretreatment with L-NAME caused similar leftward shifts of the phenylephrine concentration response curves in diabetic and non-diabetic vessels. The ob/ob aortae contracted in response to phenylephrine with roughly twice the force while they were not stiffer than control aortae. L-NAME caused a greater percentage increase in maximal force in the control than in the ob/ob tissue. Denudation potentiated force in the control aortae, but not in the ob/ob aortae. Endothelium-dependent relaxation in the ob/ob aortae and mesenteric arteries was impaired as manifested by a decreased sensitivity and maximal relaxation to acetylcholine, while the aortic basal eNOS mRNA levels did not differ between the two strains. In addition, ob/ob aortae were less sensitive to the nitric oxide donor sodium nitroprusside. Inhibition of endogenous prostaglandin synthesis with indomethacin (10 microM) partly normalized the contractile response of the ob/ob aortae and enhanced their endothelium-dependent relaxation. Neither blockade of endothelin-1 receptors (bosentan, 10 microM) nor PKC inhibition (calphostin, 1 microM) affected the contractile response to phenylephrine in the mouse aortae of either strain. In conclusion, vascular dysfunction in the aorta and mesenteric artery of ob/ob mice are due to increased smooth muscle contractility and impaired dilation but not to changes in elasticity of the vascular wall. Endothelium-produced prostaglandins contribute to the increased vasoconstriction.


Subject(s)
Diabetes Mellitus, Type 2/physiopathology , Muscle Contraction/physiology , Muscle, Smooth, Vascular/physiology , Animals , Aorta/cytology , Aorta/physiology , Cell Count , Diabetes Mellitus, Type 2/metabolism , Disease Models, Animal , Elasticity , Glucose/metabolism , Lipid Metabolism , Mesenteric Arteries/physiology , Mice , Mice, Inbred C57BL , Mice, Obese , Muscle, Smooth, Vascular/cytology , Myocytes, Smooth Muscle/cytology , Myocytes, Smooth Muscle/metabolism , Nitric Oxide/metabolism , Nitric Oxide Synthase/genetics , Nitric Oxide Synthase Type II , Nitric Oxide Synthase Type III , Protein Kinase C/metabolism , Proteoglycans/metabolism , RNA, Messenger/analysis , Receptors, Endothelin/metabolism
11.
Expert Opin Ther Targets ; 7(1): 49-59, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12556202

ABSTRACT

Chronic heart failure is characterised by functional deficiencies of the myocardium. Structural abnormalities of the left ventricular wall occur in many cases as a consequence of myocardial infarction (MI). The overburdened postMI heart is characterised by an active reorganisation of the remaining myocardium. Increased expression and activity of matrix metalloproteinases lead to altered composition and arrangement of the extracellular matrix, which is accompanied by eccentric hypertrophy of cardiomyocytes. The altered geometry of the heart muscle fosters biomechanical stress, driving the heart into a dead-end situation. Clearly, novel therapeutic concepts must be developed to reverse this process. Part II of the current review will focus on emerging therapeutic targets for small molecule therapeutics in the fields of cardiac remodelling and impaired survival of cardiomyocytes in the diseased heart. Finally, innovative therapeutic concepts for heart gene therapy and replacement options for destroyed post-MI myocardium using embryonic and adult stem cells are described.


Subject(s)
Cardiovascular Agents/therapeutic use , Heart Failure/drug therapy , Apoptosis/drug effects , Apoptosis Regulatory Proteins/physiology , Cardiovascular Agents/pharmacology , Cell- and Tissue-Based Therapy , Cytokines/physiology , Drug Design , Extracellular Matrix/drug effects , Female , Genetic Therapy , Heart Failure/etiology , Heart Failure/physiopathology , Humans , Male , Muscle Proteins/physiology , Myocardial Infarction/complications , Signal Transduction/drug effects , Ventricular Remodeling/drug effects
12.
FASEB J ; 17(1): 28-37, 2003 Jan.
Article in English | MEDLINE | ID: mdl-12522109

ABSTRACT

We investigated the role of mitochondria (MT) in calcium signaling in a culture of rat aortic smooth muscle cells. We used targeted aequorin to selectively measure [Ca2+] in this organelle. Our results reveal that smooth muscle cell stimulation with agonists causes a large, transient increase in mitochondrial [Ca2+] ([Ca2+]m). This large transient can be blocked with inhibitors of the sarco-endoplasmic reticulum Ca2+-ATPase, suggesting a close relationship between the sarcoplasmic reticulum (SR) and the mitochondria. FCCP completely abolished the response to agonists, and targeted mitochondrial GFP revealed a vast tubular network of MT in these cells. When added before stimulation with ATP, IP3 inhibitors partially blocked the ATP-induced rise in mitochondrial Ca2+ release. The role of the Na+/Ca2+ exchanger (NCX) was examined by removing extracellular Na+. This procedure prevented the decrease in the [Ca2+]m transient normally seen on removal of extracellular Ca2+. We propose a functional linkage of MT and SR dependent on a narrow junctional space between the two organelles in which Ca2+ diffusion is restricted. Approximately half of the mitochondria appear to be associated with the superficial SR, which communicates with the extracellular space via NCX.


Subject(s)
Calcium Signaling , Mitochondria/metabolism , Muscle, Smooth, Vascular/metabolism , Adenosine Triphosphate/pharmacology , Aequorin/genetics , Animals , Calcium Channel Blockers/pharmacology , Calcium Channels/physiology , Calcium-Transporting ATPases/antagonists & inhibitors , Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone/pharmacology , Cell Line , Cells, Cultured , Inositol 1,4,5-Trisphosphate Receptors , Models, Biological , Muscle, Smooth, Vascular/drug effects , Muscle, Smooth, Vascular/ultrastructure , Rats , Receptors, Cytoplasmic and Nuclear/physiology , Sarcoplasmic Reticulum Calcium-Transporting ATPases , Sodium-Calcium Exchanger/physiology , Uncoupling Agents/pharmacology , Vasopressins/pharmacology
13.
Expert Opin Ther Targets ; 6(6): 649-58, 2002 Dec.
Article in English | MEDLINE | ID: mdl-12472378

ABSTRACT

Chronic heart failure (CHF) is a life threatening disease with an enormous medical requirement. Approximately 15 million people worldwide suffer from CHF. The prevalence will inevitably increase due to the ageing population. Nevertheless, current treatment options based on angiotensin-converting enzyme inhibitors and beta-adrenergic receptor antagonists merely slow progression of the disease. Novel treatment concepts based on new therapeutic targets must have the capability to reverse the severity of this disease. This review, focusing on the emerging targets in the most promising therapeutic areas for the treatment of CHF, will be divided into two parts. In Part I, disease concepts such as altered calcium handling and ion channel activity, pathophysiological hypertrophy and inefficient cardiac metabolism are discussed. Validation status and potential therapeutic value for new targets in each research field is given by summarising the results of in vitro and in vivo studies.


Subject(s)
Cardiovascular Agents/therapeutic use , Heart Failure/drug therapy , Animals , Anti-Arrhythmia Agents/pharmacology , Anti-Arrhythmia Agents/therapeutic use , Antihypertensive Agents/pharmacology , Antihypertensive Agents/therapeutic use , Arrhythmias, Cardiac/etiology , Arrhythmias, Cardiac/prevention & control , Calcium Channel Blockers/pharmacology , Calcium Channel Blockers/therapeutic use , Calcium Channels/drug effects , Calcium Channels/physiology , Calcium Signaling/drug effects , Cardiomyopathy, Hypertrophic/complications , Cardiomyopathy, Hypertrophic/drug therapy , Cardiomyopathy, Hypertrophic/metabolism , Cardiovascular Agents/pharmacology , Energy Metabolism/drug effects , Fatty Acids/metabolism , Heart Failure/etiology , Heart Failure/metabolism , Humans , Ion Channels/drug effects , MAP Kinase Signaling System/drug effects , Mice , Muscle Proteins/antagonists & inhibitors , Muscle Proteins/physiology , PPAR alpha/physiology , Rats , Transcription Factors/antagonists & inhibitors , Transcription Factors/physiology
14.
Am J Physiol Heart Circ Physiol ; 282(5): H1768-77, 2002 May.
Article in English | MEDLINE | ID: mdl-11959642

ABSTRACT

Alpha(1)-aderenoceptor-mediated constriction of rabbit inferior vena cava (IVC) is signaled by asynchronous wavelike Ca(2+) oscillations in the in situ smooth muscle. We have shown previously that a putative nonselective cationic channel (NSCC) is required for these oscillations. In this report, we show that the application of 2-aminoethoxyphenyl borate (2-APB) to antagonize inositol 1,4,5-trisphosphate (InsP(3))-sensitive Ca(2+) release channels (IP(3)R channels) can prevent the initiation and abolish ongoing alpha(1)-aderenoceptor-mediated tonic constriction of the venous smooth muscle by inhibiting the generation of these intracellular Ca(2+) concentration ([Ca(2+)](i)) oscillations. The observed effects of 2-APB can only be attributed to its selective inhibition on the IP(3)R channels, not to its slight inhibition of the L-type voltage-gated Ca(2+) channel and the sarco(endo)plasmic reticulum Ca(2+) ATPase. Furthermore, 2-APB had no effect on the ryanodine-sensitive Ca(2+) release channel and the store-operated channel (SOC) in the IVC. These results indicate that the putative NSCC involved in refilling the sarcoplasmic reticulum (SR) and maintaining the tonic contraction is most likely an SOC-type channel because it appears to be activated by IP(3)R-channel-mediated SR Ca(2+) release or store depletion. This is in accordance with its sensitivity to Ni(2+) and La(3+) (SOC blockers). More interestingly, RT-PCR analysis indicates that transient receptor potential (Trp1) mRNA is strongly expressed in the rabbit IVC. The Trp1 gene is known to encode a component of the store-operated NSCC. These new data suggest that the activation of both the IP(3)R channels and the SOC are required for PE-mediated [Ca(2+)](i) oscillations and constriction of the rabbit IVC.


Subject(s)
Calcium Channels/physiology , Capsid Proteins , Inositol 1,4,5-Trisphosphate/pharmacology , Ion Channel Gating/physiology , Receptors, Adrenergic, alpha/physiology , Vena Cava, Inferior/physiology , Animals , Boron Compounds/pharmacology , Calcium Channels/drug effects , Capsid/antagonists & inhibitors , Capsid/physiology , Fungal Proteins/genetics , Lanthanum/pharmacology , Male , Muscle, Smooth, Vascular/drug effects , Muscle, Smooth, Vascular/physiology , Nickel/pharmacology , RNA, Messenger/analysis , Rabbits , Reverse Transcriptase Polymerase Chain Reaction , Vasoconstriction/drug effects
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