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1.
J Orthop Res ; 30(12): 2038-45, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22622799

RESUMO

We previously showed that interstitial fluid pressure (IFP) may be an alternate regulator of angiogenesis in solid tumors. Given the accepted link between hypoxia-induced factor and angiogenesis this study investigated the effect of IFP on hypoxia-inducible factor (HIF-1α) and vascular endothelial growth factor (VEGF) in human osteosarcoma xenografts in SCID mice and in different hypoxic environments. Tumors were grown either at heterotopic (flank) or orthotopic (medullary canal of the proximal tibia) sites in the host animal. Microfluidic probes determined pH, O(2)-saturation, IFP, and peripheral blood flow perfusion continuously. We assessed tumor growth in the orthotopic site (n = 15) by softex radiographs weekly, 3D microCT, histological evaluation, and for molecular responses. An increased cytoplasmic immunohistostaining of cells for HIF-1α (p = 0.03) and VEGF-A (p = 0.004) on the outer periphery was noted compared to the tumor center, with VEGFR2 uniformly stained throughout. This paralleled a raised state of interstitial hypertension (p = 0.007) in the tumor center relative to the peripheral surface but was inconsistent with a state of hypoxia (p = 0.03) in the tumor center. In vitro culture of human osteosarcoma cell lines (HOS, U2OS) and a human osteoblast control at 0- and 20-mmHg of hydrostatic pressure revealed suppression of HIF-1α (p = 0.02) and VEGF-A (p = 0.02) gene expression when IFP was raised, while the effect on VEGFR1 was equivocal. This study proposes an alternative regulatory angiogenic pathway via the influence of IFP on cancer cell function. The identification of a mechanistic cellular link to the physical parameter becomes an important tool to evaluate cancer cell growth within solid tumors.


Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neovascularização Patológica , Osteossarcoma/metabolismo , Animais , Hipóxia Celular , Linhagem Celular Tumoral , Líquido Extracelular/metabolismo , Regulação da Expressão Gênica , Humanos , Hipóxia , Camundongos , Transplante de Neoplasias , Osteoblastos/metabolismo , Pressão , Transdução de Sinais , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/biossíntese
2.
J Cell Biochem ; 113(7): 2330-45, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22573552

RESUMO

The expression of inflammatory cytokines and growth factors in surgically repaired lacerated muscles over a 12-week recovery phase was investigated. We hypothesized that these expression levels are influenced by both neural and muscular damage within lacerated muscles. Microarrays were confirmed with reverse transcription-polymerase chain reaction assays and histology of biopsies at the lesion of three simulated lacerated muscle models in 130 adult rats. The lacerated medial gastrocnemius with the main intramuscular nerve branch either cut (DN), crushed but leaving an intact nerve sheath (RN); or preserved intact (PN) were compared. At 4 weeks, DN had a higher number of interleukins up-regulated. DN and RN also had a set of Bmp genes significantly expressed between 2 and 8 weeks (P ≤ 0.05). By 12 weeks, DN had a poorer and slower myogenic recovery and greater fibrosis formation correlating with an up-regulation of the Tgf-ß gene family. DN also showed poorer re-innervation with higher mRNA expression levels of nerve growth factor (Ngf) and brain-derived neurotrophin growth factor (Bdnf) over RN and PN. This study demonstrates that the inflammatory response over 12 weeks in lacerated muscles may be directed by the type of intramuscular nerve damage, which can influence the recovery at the lesion site. Inflammatory-related genes associated to the type of intramuscular nerve damage include Gas-6, Artemin, Fgf10, Gdf8, Cntf, Lif, and Igf-2. qPCR also found up-regulation of Bdnf (1-week), neurotrophin-3 (2w), Lif (4w), and Ngf (4w, 8w) mRNA expressions in DN, making them possible candidates for therapeutic treatment to arrest the poor recovery in muscle lacerations (250).


Assuntos
Citocinas/biossíntese , Músculo Esquelético/lesões , Músculo Esquelético/inervação , Fator de Crescimento Neural/biossíntese , Regeneração Nervosa , Fator de Crescimento Transformador beta/biossíntese , Animais , Fator Neurotrófico Derivado do Encéfalo/biossíntese , Citocinas/metabolismo , Fibrose/patologia , Inflamação/imunologia , Fator Inibidor de Leucemia/biossíntese , Músculo Esquelético/patologia , Músculo Esquelético/cirurgia , Compressão Nervosa , Fator de Crescimento Neural/genética , Neurotrofina 3/biossíntese , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Fator de Crescimento Transformador beta/genética
3.
J Cell Physiol ; 221(3): 778-88, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19746444

RESUMO

Osteosarcomas are the most prevalent primary bone tumors found in pediatric patients. To understand their molecular etiology, cell culture models are used to define disease mechanisms under controlled conditions. Many osteosarcoma cell lines (e.g., SAOS-2, U2OS, MG63) are derived from Caucasian patients. However, patients exhibit individual and ethnic differences in their responsiveness to irradiation and chemotherapy. This motivated the establishment of osteosarcoma cell lines (OS1, OS2, OS3) from three ethnically Chinese patients. OS1 cells, derived from a pre-chemotherapeutic tumor in the femur of a 6-year-old female, were examined for molecular markers characteristic for osteoblasts, stem cells, and cell cycle control by immunohistochemistry, reverse transcriptase-PCR, Western blotting and flow cytometry. OS1 have aberrant G-banded karyotypes, possibly reflecting chromosomal abnormalities related to p53 deficiency. OS1 had ossification profiles similar to human fetal osteoblasts rather than SAOS-2 which ossifies ab initio (P < 0.05). Absence of p53 correlates with increased Runx2 expression, while the slow proliferation of OS1 cells is perhaps attenuated by pRB retention. OS1 express mesenchymal stem cell markers (CD44, CD105) and differ in relative expression of CD29, CD63, and CD71 to SAOS-2. (P < 0.05). Cell cycle synchronization with nocodazole did not affect Runx2 and CDK1 levels but decreased cyclin-E and increased cyclin-A (P < 0.05). Xenotransplantion of OS1 in SCID mice yields spontaneous tumors that were larger and grew faster than SAOS-2 transplants. Hence, OS1 is a new osteosarcoma cell culture model derived from a pre-chemotherapeutic ethnic Chinese patient, for mechanistic studies and development of therapeutic strategies to counteract metastasis and deregulation of mesenchymal development.


Assuntos
Diferenciação Celular , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Osteoblastos/patologia , Osteossarcoma/metabolismo , Osteossarcoma/patologia , Proteína do Retinoblastoma/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Adolescente , Animais , Antígenos CD/metabolismo , Povo Asiático , Calcificação Fisiológica/fisiologia , Ciclo Celular/efeitos dos fármacos , Desdiferenciação Celular , Linhagem Celular Tumoral , Proliferação de Células , Criança , Aberrações Cromossômicas , Colágeno Tipo I/metabolismo , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Ciclinas/genética , Ciclinas/metabolismo , Feminino , Expressão Gênica/genética , Humanos , Antígeno Ki-67/metabolismo , Camundongos , Camundongos SCID , Nocodazol/farmacologia , Osteocalcina/metabolismo , Osteossarcoma/diagnóstico , Osteossarcoma/genética , Proteína do Retinoblastoma/genética , Proteína Supressora de Tumor p53/genética , Ensaios Antitumorais Modelo de Xenoenxerto
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