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1.
Cancers (Basel) ; 15(21)2023 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-37958331

RESUMO

INTRODUCTION: The LenaMain trial (NCT00891384) reported increased progression-free survival with 25 mg of lenalidomide maintenance compared to 5 mg. Here, we report the patient-reported outcomes. MATERIALS AND METHODS: Scores obtained from the EORTC Quality of Life Questionnaire C30 were analyzed for longitudinal changes from baseline within the groups as well as cross-sectional scores. RESULTS: Compliance rates were high, with 95.7% at baseline and 70% during maintenance. At study entry, scores were high for functioning and low for symptoms. During maintenance, the median global health status/quality of life (GHS/QoL) was constant, without significant differences over time (median GHS/QoL: 68 at baseline and 58 for Len high and 68 for Len low at 2 years) and between treatment arms (mean change < 2). Similarly, most functional scale domains were constant. Notably, diarrhea increased consistently for both treatment arms (baseline: -1.905 (range: -5.78-1.97); end of year 2: 16.071 (range: 5.72-26.42); p < 0.05). The subgroup analysis showed that neither disease activity, duration of treatment, nor adverse events affected the health-related quality of life (HR-QoL) or utility. CONCLUSION: High baseline scores were maintained throughout the trial without significant differences between the Len dosages, which supports continuous treatment with a dose tailored to patients' HR-QoL.

2.
BMC Biol ; 21(1): 21, 2023 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-36737754

RESUMO

BACKGROUND: In a range of human disorders such as multiple myeloma (MM), immunoglobulin light chains (IgLCs) can be produced at very high concentrations. This can lead to pathological aggregation and deposition of IgLCs in different tissues, which in turn leads to severe and potentially fatal organ damage. However, IgLCs can also be highly soluble and non-toxic. It is generally thought that the cause for this differential solubility behaviour is solely found within the IgLC amino acid sequences, and a variety of individual sequence-related biophysical properties (e.g. thermal stability, dimerisation) have been proposed in different studies as major determinants of the aggregation in vivo. Here, we investigate biophysical properties underlying IgLC amyloidogenicity. RESULTS: We introduce a novel and systematic workflow, Thermodynamic and Aggregation Fingerprinting (ThAgg-Fip), for detailed biophysical characterisation, and apply it to nine different MM patient-derived IgLCs. Our set of pathogenic IgLCs spans the entire range of values in those parameters previously proposed to define in vivo amyloidogenicity; however, none actually forms amyloid in patients. Even more surprisingly, we were able to show that all our IgLCs are able to form amyloid fibrils readily in vitro under the influence of proteolytic cleavage by co-purified cathepsins. CONCLUSIONS: We show that (I) in vivo aggregation behaviour is unlikely to be mechanistically linked to any single biophysical or biochemical parameter and (II) amyloidogenic potential is widespread in IgLC sequences and is not confined to those sequences that form amyloid fibrils in patients. Our findings suggest that protein sequence, environmental conditions and presence and action of proteases all determine the ability of light chains to form amyloid fibrils in patients.


Assuntos
Cadeias Leves de Imunoglobulina , Mieloma Múltiplo , Humanos , Cadeias Leves de Imunoglobulina/química , Cadeias Leves de Imunoglobulina/metabolismo , Amiloide/metabolismo , Sequência de Aminoácidos , Proteólise
3.
Drug Deliv Transl Res ; 13(4): 915-923, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36592287

RESUMO

Despite the introduction of multiple new drugs and combination therapies, conventional dexamethasone remains a cornerstone in the treatment of multiple myeloma (MM). Its application is, however, limited by frequent adverse effects of which the increased infection rate may have the strongest clinical impact. The efficacy-safety ratio of dexamethasone in MM may be increased by encapsulation in long-circulating PEG-liposomes, thereby both enhancing drug delivery to MM lesions and reducing systemic corticosteroid exposure. We evaluated the preliminary safety and feasibility of a single intravenous (i.v.) infusion of pegylated liposomal dexamethasone phosphate (Dex-PL) in heavily pretreated relapsing or progressive symptomatic MM patients within a phase I open-label non-comparative interventional trial at two dose levels. In the 7 patients that were enrolled (prior to having to close the study prematurely due to slow recruitment), Dex-PL was found to be well tolerated and, as compared to conventional dexamethasone, no new or unexpected adverse events were detected. Pharmacokinetic analysis showed high and persisting concentrations of dexamethasone in the circulation for over a week after i.v. administration, likely caused by the long-circulation half-life of the liposomes that retain dexamethasone as the inactive phosphate prodrug form, something which could significantly limit systemic exposure to the active parent drug. Thus, despite the limitations of this small first-in-man trial, Dex-PL seems safe and well tolerated without severe side effects. Follow-up studies are needed to confirm this in a larger patient cohort and to evaluate if i.v. Dex-PL can provide a safer and more efficacious dexamethasone treatment option for MM.


Assuntos
Mieloma Múltiplo , Humanos , Protocolos de Quimioterapia Combinada Antineoplásica , Dexametasona/efeitos adversos , Lipossomos/uso terapêutico , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/etiologia , Mieloma Múltiplo/patologia , Resultado do Tratamento
4.
Cancers (Basel) ; 14(9)2022 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-35565276

RESUMO

Randomized controlled trials (RCT) are the driver of therapeutic innovations. However, it has been frequently shown that less than 5% of adult cancer patients enroll in clinical trials, although 70% of patients are considered as being willing to participate. Barriers to trial participation have been extensively studied. Although there is evidence that trial participation correlates with improved survival and reduced mortality, the rate of participation has not changed substantially. We provide retrospective data from a single-center analysis of 411 patients with multiple myeloma (MM) who were treated at the University Hospital Duesseldorf in Germany between January 2014 and December 2016. Each patient was analyzed for the real-world possibility of participating in a clinical study, based on the inclusion and exclusion (I/E) criteria and the recruiting period of open studies. The overall rate of study participation was 19%. A total of 53% of NDMM patients were eligible for first-line studies (GMMG-HD6, LenaMain). Of these, 80% consented to enrolment (42% of all). In contrast, only 38% of the RRMM population was eligible (GMMG-Relapse, Castor, Tourmaline, Admyre). Of these, only 22% (7% of all) consented. This was confirmed by virtual analysis, showing that only 29% of all RRMM patients would have been eligible for six internationally recruiting trials leading to later drug approval. The majority of cases were rendered ineligible by only one I/E criterion. The most common criteria were study-specific (prior therapies or refractory disease to a specific drug), kidney disease, and previous malignancy, followed by internal, neurologic, and infectious disease. In summary, this single-center analysis showed that I/E criteria permit study participation for most NNDM patients, with a dramatic decrease in the RRMM population. This is aggravated by the fact that the willingness for study participation also significantly declines in RRMM. Thus, addressing patient expectations and priorities seems to be the most promising approach to increasing patient enrollment in clinical trials.

5.
BMC Med Imaging ; 22(1): 63, 2022 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-35379187

RESUMO

PURPOSE: While 18F-FDG PET/CT yields valuable prognostic information for patients in first-line therapy of multiple myeloma (MM), its prognostic relevance in relapse is not established. Available studies of relapsed MM describe prognostic thresholds for frequently used PET/CT parameters that are significantly higher than those identified in the first-line setting. The purpose of this study was to evaluate the prognostic role of PET/CT in relapsed MM, based on parameters used in the first-line setting. METHODS: Our retrospective study included 36 patients with MM who had received autologous or allogeneic stem cell transplantation, suffered at least one relapse, and underwent FDG-PET/CT at relapse. Number of focal bone lesions (FL), maximal standardised uptake value (SUVmax), and presence of PET-positive extramedullary lesions (EMD) were analysed. RESULTS: For the number of FLs, the prognostic value was demonstrated with a cut-off of > 3 (median OS 3.8 months vs. not reached, p = 0.003). Median OS of patients with SUVmax ≤ 4 was not reached, while it was 3.9 months in patients with SUVmax > 4 (p = 0.014). Presence of EMD was a significant prognostic parameter too, with median OS of 3.6 months versus not reached (p = 0.004). The above-mentioned parameters showed prognostic significance for PFS as well. Combination of higher ISS stage and PET/CT parameters identified patients with particularly short OS (3.7 months vs. not reached, p < 0.001) and PFS (3.6 vs. 11.7 months p < 0.001). CONCLUSION: The PET/CT parameters SUVmax > 4, nFL > 3, and presence of EMD identify patients with poor prognosis not only in the first-line setting but also in relapsed MM.


Assuntos
Fluordesoxiglucose F18 , Mieloma Múltiplo , Humanos , Mieloma Múltiplo/diagnóstico por imagem , Mieloma Múltiplo/tratamento farmacológico , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Prognóstico , Estudos Retrospectivos
6.
Anal Chem ; 93(30): 10627-10634, 2021 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-34292722

RESUMO

In multiple myeloma diseases, monoclonal immunoglobulin light chains (LCs) are abundantly produced, with, as a consequence in some cases, the formation of deposits affecting various organs, such as the kidney, while in other cases remaining soluble up to concentrations of several g·L-1 in plasma. The exact factors crucial for the solubility of LCs are poorly understood, but it can be hypothesized that their amino acid sequence plays an important role. Determining the precise sequences of patient-derived LCs is therefore highly desirable. We establish here a novel de novo sequencing workflow for patient-derived LCs, based on the combination of bottom-up and top-down proteomics without database search. PEAKS is used for the de novo sequencing of peptides that are further assembled into full length LC sequences using ALPS. Top-down proteomics provides the molecular masses of proteoforms and allows the exact determination of the amino acid sequence including all posttranslational modifications. This pipeline is then used for the complete de novo sequencing of LCs extracted from the urine of 10 patients with multiple myeloma. We show that for the bottom-up part, digestions with trypsin and Nepenthes digestive fluid are sufficient to produce overlapping peptides able to generate the best sequence candidates. Top-down proteomics is absolutely required to achieve 100% final sequence coverage and characterize clinical samples containing several LCs. Our work highlights an unexpected range of modifications.


Assuntos
Mieloma Múltiplo , Sequência de Aminoácidos , Humanos , Cadeias Leves de Imunoglobulina/genética , Peptídeos/genética , Proteômica , Análise de Sequência de Proteína
7.
Clin Cancer Res ; 26(22): 5879-5886, 2020 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-32817078

RESUMO

PURPOSE: For multiple myeloma, high-dose chemotherapy and autologous blood stem-cell transplantation (ASCT) followed by lenalidomide maintenance (LenMT) at 10-15 mg/day is considered standard of care. However, dose reductions due to side effects are common and median LenMT doses achieved over time may remain lower. Dose response during LenMT has never been investigated. PATIENTS AND METHODS: In a multicenter, randomized, open-label trial, patients with multiple myeloma after ASCT and high-dose lenalidomide consolidation therapy (CT) at 25 mg/day were randomized to receive LenMT at either 25 or 5 mg/day. Primary endpoint was progression-free survival (PFS). RESULTS: Ninety-four patients (median age, 58 years) were randomized to either arm, with 22% having International Staging System (ISS) stage 3 and 22% being in complete remission (CR). After median follow-up of 46.7 months, median doses of 14.5 and 5 mg/day were achieved in the two arms; 53% of dose reductions occurring during CT. In the high- and the low-dose arm, median PFS was 44.8 and 33.0 months (HR, 0.65; 95% CI, 0.44-0.97; P = 0.032), 36% and 23% of patients had stringent CR as best response (P = 0.08), and 4-year OS was 79% and 67% (P = 0.16), respectively. Hematologic toxicity, grade ≥3 neutropenia, and infections were initially more common with LenMT 25 mg, but decreased after dose adjustments. SPM incidence and quality-of-life (QoL) scores in both arms were similar. CONCLUSIONS: LenMT dose correlated with efficacy and toxicity. High rates of dose reductions during CT argue against a high starting dose. However, continuous up- and down-titration for each patient to the current maximum tolerated dose is prudent.


Assuntos
Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Lenalidomida/administração & dosagem , Mieloma Múltiplo/tratamento farmacológico , Transplante de Células-Tronco de Sangue Periférico/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Quimioterapia de Consolidação , Intervalo Livre de Doença , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Mieloma Múltiplo/patologia , Intervalo Livre de Progressão , Qualidade de Vida
8.
PeerJ ; 8: e8771, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32211238

RESUMO

In light chain (LC) diseases, monoclonal immunoglobulin LCs are abundantly produced with the consequence in some cases to form deposits of a fibrillar or amorphous nature affecting various organs, such as heart and kidney. The factors that determine the solubility of any given LC in vivo are still not well understood. We hypothesize that some of the biochemical properties of the LCs that have been shown to correlate with amyloid fibril formation in patients also can be used as predictors for the degree of kidney damage in a patient group that is only biased by protein availability. We performed detailed biochemical and biophysical investigations of light chains extracted and purified from the urine of a group of 20 patients with light chain disease. For all samples that contained a sufficiently high concentration of LC, we quantified the unfolding temperature of the LCs, the monomer-dimer distribution, the digestibility by trypsin and the formation of amyloid fibrils under various conditions of pH and reducing agent. We correlated the results of our biophysical and biochemical experiments with the degree of kidney damage in the patient group and found that most of these parameters do not correlate with kidney damage as defined by clinical parameters. However, the patients with the greatest impairment of kidney function have light chains which display very poor digestibility by trypsin. Most of the LC properties reported before to be predictors of amyloid formation cannot be used to assess the degree of kidney damage. Our finding that poor trypsin digestibility correlates with kidney damage warrants further investigation in order to probe a putative mechanistic link between these factors.

10.
Int J Cancer ; 139(10): 2343-52, 2016 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-27389073

RESUMO

New drugs for the treatment of multiple myeloma (MM) comprise immunomodulatory substances such as lenalidomide and related compounds. While lenalidomide has found its way into first-line treatment as well as into relapse therapy, little is known about lenalidomide effects on normal hematopoietic stem and progenitor cells (HSPCs). In this study, we investigated whether HSPCs are influenced by lenalidomide on a phenotypic, functional and gene expression level. For that purpose, samples from patients with MM were obtained who underwent equivalent first-line treatment including induction therapy, cytotoxic stem cell mobilization and high-dose melphalan therapy followed by autologous blood stem cell transplantation and a subsequent uniform lenalidomide consolidation treatment within a prospective clinical trial. We found that after six months of lenalidomide therapy, the number of CD34(+) HSPCs decreased. Additionally, lenalidomide affects the numerical composition of hematopoietic cells in the bone marrow while it does not affect long-term HSPC proliferation in vitro. We found a significant amplification of fetal hemoglobin (HbF) expression on a transcriptional level and can confirm a stimulated erythropoiesis on a phenotypic level. These effects were accompanied by silencing of the TGF-ß signaling pathway on the gene expression and protein level that is known to be amplified in active MM. However, these pleiotropic effects gave no evidence for mutagenic potential. In conclusion, lenalidomide does not exert long-term effects on proliferation of HSPCs but instead promotes erythropoiesis by shifting hemoglobin expression toward HbF and by silencing the TGF-ß signaling pathway.


Assuntos
Eritropoese/efeitos dos fármacos , Mieloma Múltiplo/sangue , Mieloma Múltiplo/tratamento farmacológico , Mielopoese/efeitos dos fármacos , Talidomida/análogos & derivados , Inibidores da Angiogênese/uso terapêutico , Medula Óssea/efeitos dos fármacos , Quimioterapia de Consolidação , Hemoglobina Fetal/metabolismo , Células-Tronco Hematopoéticas/efeitos dos fármacos , Humanos , Lenalidomida , Pessoa de Meia-Idade , Talidomida/uso terapêutico
11.
Aging Cell ; 14(1): 139-47, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25481981

RESUMO

The cyclin-dependent kinase (Cdk) inhibitor p16(Ink4a) (p16) is a canonical mediator of cellular senescence and accumulates in aging tissues, where it constrains proliferation of some progenitor cells. However, whether p16 induction in tissues is sufficient to inhibit cell proliferation, mediate senescence, and/or impose aging features has remained unclear. To address these issues, we generated transgenic mice that permit conditional p16 expression. Broad induction at weaning inhibited proliferation of intestinal transit-amplifying and Lgr5+ stem cells and rapidly imposed features of aging, including hair loss, skin wrinkling, reduced body weight and subcutaneous fat, an increased myeloid fraction in peripheral blood, poor dentition, and cataracts. Aging features were observed with multiple combinations of p16 transgenes and transactivators and were largely abrogated by a germline Cdk4 R24C mutation, confirming that they reflect Cdk inhibition. Senescence markers were not found, and de-induction of p16, even after weeks of sustained expression, allowed rapid recovery of intestinal cell proliferation and reversal of aging features in most mice. These results suggest that p16-mediated inhibition of Cdk activity is sufficient to inhibit cell proliferation and impose aging features in somatic tissues of mammals and that at least some of these aging features are reversible.


Assuntos
Senilidade Prematura/patologia , Ciclo Celular , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Animais , Proliferação de Células , Quinase 4 Dependente de Ciclina/metabolismo , Células Epiteliais/citologia , Humanos , Intestinos/citologia , Camundongos Transgênicos , Reprodutibilidade dos Testes , Células-Tronco/citologia
12.
Cancer Biol Ther ; 15(2): 170-1, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24365855

RESUMO

NFκB represents a key transcription factor within the inflammatory tumor microenvironment; however, NFκB's function in tumor-initiating cells has not been examined yet. A recent Cell paper by Schwitalla et al. reports that NFκB modulates Wnt signaling and shows that enhanced Wnt activation induces dedifferentiation of nonstem cells that acquire tumor-initiating capacity.


Assuntos
Desdiferenciação Celular , Transformação Celular Neoplásica , Neoplasias do Colo/patologia , Células-Tronco Neoplásicas/patologia , Animais , Feminino , Humanos , Masculino
13.
Transl Oncol ; 3(1): 33-42, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20165693

RESUMO

Barrett esophagus is an epithelial metaplasia that predisposes to adenocarcinoma. Better markers of cancer risk are urgently needed to identify those patients who are likely to benefit most from emerging methods of endoscopic ablation. Disease progression is associated with genomic DNA changes (segmental gains, losses, or loss of heterozygosity). Although these changes are not easily assayed directly, we hypothesized that the underlying DNA damage should activate a DNA damage response (DDR), detectable by immunohistochemical (IHC) assays of checkpoint proteins and the resulting replicative phase cell cycle delays. Surgical specimens and endoscopic biopsies (N = 28) were subjected to IHC for the cell cycle markers cyclin A and phosphorylated histone H3 (P-H3), the DDR markers gammaH2AX and phosphorylated ATM/ATR substrates (P-ATM/ATRsub), and the DNA damage-responsive tumor suppressors p16 and p53. Correlations were made with histologic diagnoses. The fractions of cells that stained for cyclin A, P-H3, and gammaH2AX increased in parallel in dysplastic tissue, consistent with checkpoint-mediated cell cycle delays. Foci of nuclear gammaH2AX and P-ATM/ATRsub were demonstrated by standard and confocal immunofluorescence. Staining for p16 was more prevalent in early-stage disease with lower staining for gammaH2AX and P-H3. Staining for p53 was moderately increased in some early-stage disease and strongly increased in some advanced disease, consistent with checkpoint-mediated induction and mutational inactivation of p53, respectively. We suggest that IHC for DDR-associated markers may help stratify risk of disease progression in Barrett.

14.
Cancer Prev Res (Phila) ; 2(9): 800-6, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19723896

RESUMO

Despite advances in screening and treatment, colorectal cancer remains the second leading cause of cancer-related death in the United States. Cyclin-dependent kinases (Cdk) are deregulated in colorectal cancer by silencing of the Cdk inhibitor p16(Ink4a) and other mechanisms. We tested whether the small molecule Cdk inhibitor SNS-032 (formerly BMS-387032), which targets Cdk2, Cdk7, and Cdk9, can prevent intestinal tumorigenesis in mouse models. We generated mice with high intestinal tumor loads by combining the multiple intestinal neoplasia (Min) mutation with Ink4a/Arf mutations and inducing colitis with dextran sulfate sodium. p16-null Min mice (n = 17) began dextran sulfate sodium treatment at week 5 and i.p. injection of carrier or SNS-032 at week 6. Mice were sacrificed at week 12. SNS-032 was well tolerated and reduced colon tumor burden to 36% of that in carrier-treated mice (P < 0.001). We then extended the study to Ink4/Arf-null Min mice (n = 14) and increased the drug dose frequency. SNS-032 treatment reduced the intestinal tumor number to 25% and intestinal tumor burden to 16% of carrier-treated mice (P < 0.0001). DNA synthesis in non-neoplastic and tumor epithelial cells, detected by bromodeoxyuridine incorporation, was modestly reduced by acute SNS-032 treatment. The mitotic index, detected by histone H3 phosphorylation, was distinctly decreased (P < 0.03), and apoptosis, detected by caspase 3 activation, was increased (P < 0.005). These results show the chemoprevention of intestinal tumorigenesis by SNS-032. Our findings support further study of Cdk inhibitors for chemoprevention and therapy of colon cancer.


Assuntos
Quinases Ciclina-Dependentes/antagonistas & inibidores , Neoplasias Intestinais/prevenção & controle , Oxazóis/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Tiazóis/uso terapêutico , Fator 1 de Ribosilação do ADP/fisiologia , Animais , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Colite/enzimologia , Colite/patologia , Colite/prevenção & controle , Inibidor p16 de Quinase Dependente de Ciclina/fisiologia , Feminino , Neoplasias Intestinais/enzimologia , Neoplasias Intestinais/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosforilação/efeitos dos fármacos
15.
Gastroenterology ; 136(2): 596-606.e4, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19056388

RESUMO

BACKGROUND & AIMS: Vascular endothelial growth factor (VEGF) is expressed robustly in human colon neoplasia and is a major new "rational" target of therapy for cancers of the colon and other organs. Nonetheless, the mechanism(s) of action of VEGF-targeted therapies and the biologic roles of VEGF in tumorigenesis have not been well defined. We used a transgenic approach to directly test the hypothesis that augmented VEGF expression can drive progression of intestinal neoplasia. METHODS: Transgenic mouse lines were generated with moderate (vilVEGF1) and high (vilVEGF2) VEGF expression from the intestinal epithelium. vilVEGF1 mice were bred to Min mice (adenomatous polyposis coli [APC] +/-). Colon epithelial cells from an APC patient were cocultured with endothelial cells and fibroblasts. RESULTS: vilVEGF mice were generally healthy but displayed red small intestines. Vessels were larger and more numerous in the submucosa but not the mucosa. The mucosa showed striking stromal and epithelial hypercellularity, with increased epithelial proliferation. Many crypts formed cysts composed of relatively undifferentiated epithelial cells surrounded by cells with endothelial and myofibroblast markers. Compared with Min controls, vilVEGF1-Min mice developed 6-fold more intestinal adenomas of all sizes, with more advanced histologic features. Polycystic masses were also observed. Coculture of human colonocytes with endothelial cells and fibroblasts directly stimulated colonocyte proliferation. CONCLUSIONS: Augmented VEGF expression from intestinal epithelium potently stimulated cross talk with mesenchymal cells and proliferation of normal and neoplastic epithelium. These effects of VEGF, largely occurring prior to the canonical angiogenic switch in tumors, may be in part independent of angiogenesis.


Assuntos
Comunicação Celular/fisiologia , Mucosa Intestinal/metabolismo , Neoplasias Intestinais/metabolismo , Mesoderma/metabolismo , Neoplasias Epiteliais e Glandulares/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Polipose Adenomatosa do Colo/metabolismo , Polipose Adenomatosa do Colo/patologia , Animais , Proliferação de Células , Células Cultivadas , Técnicas de Cocultura , Colo/citologia , Colo/metabolismo , Colo/patologia , Modelos Animais de Doenças , Endotélio Vascular/citologia , Endotélio Vascular/metabolismo , Endotélio Vascular/patologia , Humanos , Mucosa Intestinal/citologia , Mucosa Intestinal/patologia , Neoplasias Intestinais/patologia , Mesoderma/citologia , Camundongos , Camundongos Transgênicos , Neoplasias Epiteliais e Glandulares/patologia
16.
Cancer Biol Ther ; 5(8): 907-8, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16969074

RESUMO

Ubiquitination plays a key role in regulating multiple oncoproteins, including those of the Myc-family. A recent Cell paper by Adhikary et al reports that a novel E3 ligase, HectH9, mediates site-specific ubiquitination of Myc and thereby fosters a switch from repression to transcriptional activation. This insight elucidates Myc's diverse properties and provides new targets for the development of anti-cancer therapy.


Assuntos
Processamento de Proteína Pós-Traducional , Proteínas Proto-Oncogênicas c-myc/metabolismo , Transcrição Gênica , Ubiquitina/metabolismo , Animais , Regulação Neoplásica da Expressão Gênica , Humanos , Ativação Transcricional , Ubiquitina-Proteína Ligases/fisiologia
17.
Cancer Biol Ther ; 4(12): 1389-94, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16322687

RESUMO

The Ink4a/Arf tumor suppressor locus is widely inactivated in cancer but little is known about the tumor biology of its two products, p16(Ink4a) (p16) and Arf. Both the p16 and Arf promoters are methylated in a significant fraction of human colon carcinomas, implying a functional role. We have demonstrated previously that Ink4a/Arf-null colon tumors display increased growth and vascularity in C57Bl6 mice carrying the Min (multiple intestinal neoplasia) mutation. We present here an analysis in a mixed genetic background of Min colon tumors (N=215) in mice with or without selective deficiencies in p16 or Arf, respectively. Absence of Arf did not significantly alter tumor formation. In contrast, tumors in mice lacking p16 were moderately larger and redder. Histological analysis demonstrated that these tumors contained significantly more pockets of necrosis (p=0.02), a marker of carcinoma in situ; less apoptosis (p=0.02); and higher red blood cell density (p=0.02, 0.006 within vessels). Biochemical analyses demonstrated increased levels of vascular endothelial cell growth factor (VEGF, p<0.01). Exogenous p16 expression in human colon tumor cells in vitro inhibited VEGF production. These results suggest that p16 constrains colon tumor progression, in part through inhibiting angiogenic signaling.


Assuntos
Neoplasias do Colo/irrigação sanguínea , Genes p16 , Neovascularização Patológica/genética , Transdução de Sinais , Proteína Supressora de Tumor p14ARF/genética , Animais , Apoptose , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Progressão da Doença , Células HT29 , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Necrose/patologia , Neovascularização Patológica/patologia , Proteína Supressora de Tumor p14ARF/fisiologia
18.
Cancer Res ; 63(16): 5105-13, 2003 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-12941841

RESUMO

The melanoma differentiation-associated gene 7 (mda-7), also called interleukin (IL)-24, suppresses the growth of some cancers in vitro and in vivo as a result of the ectopic expression of its protein. However, the function of the secreted form of the protein in cancer has not been previously studied. The purpose of this study was to determine the antiangiogenic function of a secreted form of the MDA-7/IL-24 protein (sMDA-7/IL-24). In vitro, sMDA-7/IL-24 inhibited both endothelial cell differentiation and migration of endothelial cells induced by vascular endothelial growth factor and basic fibroblast growth factor. The sMDA-7/IL-24-mediated inhibitory effect was 10-50 times more potent than endostatin, IFN-gamma, and IFN-inducible protein 10 in vitro. Furthermore, the inhibitory effect was not mediated by IFN or IFN-inducible protein 10. IL-22 receptor mediated the antiangiogenic activity of sMDA-7/IL-24. Administration of a blocking antibody to IL-22 receptor in conjunction with sMDA-7/IL-24 led to abrogation of inhibition of endothelial differentiation. sMDA-7/IL-24 inhibited vascular endothelial growth factor-induced angiogenesis as evidenced by reduced vascularization and hemoglobin content in in vivo Matrigel plug assays. In vivo, the growth of human lung tumor cells was significantly inhibited, and vascularization was reduced when the cells were mixed with 293 cells stably expressing sMDA-7/IL-24. Systemic administration of sMDA-7/IL-24 inhibited lung tumor growth in a mouse xenograft model. Associated with tumor growth inhibition was decreased tumor microvessel density and hemoglobin content, indicating the presence of antiangiogenic activity. These data demonstrate that sMDA-7/IL-24 is a novel and potent antiangiogenic effector and support the development of MDA-7/IL-24-based therapeutics.


Assuntos
Inibidores da Angiogênese/farmacologia , Interleucinas/farmacologia , Receptores de Interleucina/fisiologia , Animais , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Quimiocina CXCL10 , Quimiocinas CXC/fisiologia , Colágeno/farmacologia , Proteínas de Ligação a DNA/metabolismo , Endostatinas , Endotélio Vascular/citologia , Feminino , Genes Supressores de Tumor , Humanos , Interferon gama/fisiologia , Interleucinas/uso terapêutico , Camundongos , Camundongos Endogâmicos BALB C , Transplante de Neoplasias , Neoplasias Experimentais/tratamento farmacológico , Fragmentos de Peptídeos/farmacologia , Fator de Transcrição STAT3 , Transativadores/metabolismo , Transplante Heterólogo , Células Tumorais Cultivadas
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