RESUMO
The extent and importance of functional heterogeneity and crosstalk between tumor cells is poorly understood. Here, we describe the generation of clonal populations from a patient-derived ovarian clear cell carcinoma model which forms malignant ascites and solid peritoneal tumors upon intraperitoneal transplantation in mice. The clonal populations are engineered with secreted Gaussia luciferase to monitor tumor growth dynamics and tagged with a unique DNA barcode to track their fate in multiclonal mixtures during tumor progression. Only one clone, CL31, grows robustly, generating exclusively malignant ascites. However, multiclonal mixtures form large solid peritoneal metastases, populated almost entirely by CL31, suggesting that transient cooperative interclonal interactions are sufficient to promote metastasis of CL31. CL31 uniquely harbors ERBB2 amplification, and its acquired metastatic activity in clonal mixtures is dependent on transient exposure to amphiregulin, which is exclusively secreted by non-tumorigenic clones. Amphiregulin enhances CL31 mesothelial clearance, a prerequisite for metastasis. These findings demonstrate that transient, ostensibly innocuous tumor subpopulations can promote metastases via "hit-and-run" commensal interactions.
Assuntos
Comunicação Celular , Células Clonais/patologia , Metástase Neoplásica/patologia , Anfirregulina/metabolismo , Animais , Ascite/patologia , Carcinogênese/patologia , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/patologia , Linhagem Celular Tumoral , Proliferação de Células , Separação Celular , Estudos de Coortes , Variações do Número de Cópias de DNA/genética , Epitélio/patologia , Feminino , Amplificação de Genes , Humanos , Neoplasias Renais/genética , Neoplasias Renais/patologia , Ligantes , Camundongos SCID , Modelos Biológicos , Neoplasias Peritoneais/secundário , Fenótipo , Receptor ErbB-2/genética , Fatores de TempoRESUMO
Gene therapy for schwannomas was evaluated in two mouse models of neurofibromatosis type 2 (NF2): (1) a transgenic model in which mice express a dominant mutant form of merlin and spontaneously develop schwannomas, and (2) a xenograft model in which human schwannoma tissue is implanted subcutaneously into immune- compromised mice. In both models, schwannoma volumes were monitored by magnetic resonance imaging (MRI) and showed strong gadolinium enhancement typical of these tumors in humans. Both types of tumor were positive for the Schwann cell marker S100, and highly infectable with herpes simplex virus (HSV) vectors. Schwannomas were injected with an oncolytic HSV-1 recombinant virus vector, G47Delta, which has deletions in genes for ribonucleotide reductase (ICP6), gamma34.5, and ICP47. In the NF2 transgenic model, schwannomas were reduced by more than half their original size by 10 days after infection. In the case of subcutaneous schwannoma xenografts, reduction in size after infection occurred more slowly, with a mean reduction of onethird by 42 days after treatment. Schwannomas injected with control vehicles continued to grow slowly over time in both schwannoma models. These studies demonstrate the ability of an oncolytic recombinant HSV vector to reduce the volume of schwannoma tumors in NF2 tumor models in mice and extend the possible therapeutic applications of oncolytic vectors for benign tumors to reduce mass while minimizing nerve damage.
Assuntos
Neoplasias do Sistema Nervoso Central/terapia , Terapia Genética/métodos , Neurilemoma/terapia , Neurofibromatose 2/terapia , Simplexvirus/fisiologia , Animais , Neoplasias do Sistema Nervoso Central/patologia , Neoplasias do Sistema Nervoso Central/virologia , DNA Recombinante/genética , Modelos Animais de Doenças , Vetores Genéticos/genética , Vetores Genéticos/fisiologia , Vetores Genéticos/toxicidade , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Camundongos , Camundongos Nus , Camundongos Transgênicos , Transplante de Neoplasias , Neurilemoma/classificação , Neurilemoma/patologia , Neurilemoma/virologia , Neurofibromatose 2/patologia , Neurofibromatose 2/virologia , Simplexvirus/genéticaRESUMO
We employed gene targeting to study H2AX, a histone variant phosphorylated in chromatin surrounding DNA double-strand breaks. Mice deficient for both H2AX and p53 (H(delta/delta)P(-/-)) rapidly developed immature T and B lymphomas and solid tumors. Moreover, H2AX haploinsufficiency caused genomic instability in normal cells and, on a p53-deficient background, early onset of various tumors including more mature B lymphomas. Most H2AX(delta/delta)p53(-/-) or H2AX(+/delta)p53(-/-) B lineage lymphomas harbored chromosome 12 (IgH)/15 (c-myc) translocations with hallmarks of either aberrant V(D)J or class switch recombination. In contrast, H2AX(delta/delta)p53(-/-) thymic lymphomas had clonal translocations that did not involve antigen receptor loci and which likely occurred during cellular expansion. Thus, H2AX helps prevent aberrant repair of both programmed and general DNA breakage and, thereby, functions as a dosage-dependent suppressor of genomic instability and tumors in mice. Notably, H2AX maps to a cytogenetic region frequently altered in human cancers, possibly implicating similar functions in man.