18 research outputs found
Molecularly Characterised Xenograft Tumour Mouse Models: Valuable Tools for Evaluation of New Therapeutic Strategies for Secondary Liver Cancers
To develop and evaluate new therapeutic strategies for the treatment of human cancers, well-characterised preclinical model systems are a prerequisite. To this aim, we have established xenotransplantation mouse models and corresponding cell cultures from surgically obtained secondary human liver tumours. Established xenograft tumours were patho- and immunohistologically characterised, and expression levels of cancer-relevant genes were quantified in paired original and xenograft tumours and the derivative cell cultures applying RT-PCR-based array technology. Most of the characteristic morphological and immunohistochemical features of the original tumours were shown to be maintained. No differences were found concerning expression of genes involved in cell cycle regulation and oncogenesis. Interestingly, cytokine and matrix metalloproteinase encoding genes appeared to be expressed differentially. Thus, the established models are closely reflecting pathohistological and molecular characteristics of the selected human tumours and may therefore provide useful tools for preclinical analyses of new antitumour strategies in vivo
Reduced body growth and excessive incisor length in insertional mutants mapping to mouse Chromosome 13
Phenotypic and molecular genetic examinations of a transgenic mouse line showing developmental defects caused by a recessive insertional mutation were carried out. The mutant phenotype is characterized by general retardation of postnatal body growth and by the appearance of increased incisor length in the upper and lower jaw. The mutation causing the aberrant phenotype was mapped to Chromosome 13, 40 cM. Examination of the expression of the candidate genes did not show any alterations. This mutant mouse line provides a reproducible model for the identification and examination of gene(s) involved in growth and in the craniofacial development, including that of the jaws and teeth
Evaluation of a gene-directed enzyme-product therapy (GDEPT) in human pancreatic tumor cells and their use as in vivo models for pancreatic cancer.
BACKGROUND: Gene-directed enzyme prodrug therapy (GDEPT) is a two-step treatment protocol for solid tumors that involves the transfer of a gene encoding a prodrug-activating enzyme followed by administration of the inactive prodrug that is subsequently activated by the enzyme to its tumor toxic form. However, the establishment of such novel treatment regimes to combat pancreatic cancer requires defined and robust animal model systems. METHODS: Here, we comprehensively compared six human pancreatic cancer cell lines (PaCa-44, PANC-1, MIA PaCa-2, Hs-766T, Capan-2, and BxPc-3) in subcutaneous and orthotopical mouse models as well as in their susceptibility to different GDEPTs. RESULTS: Tumor uptake was 83% to 100% in the subcutaneous model and 60% to 100% in the orthotopical mouse model, except for Hs-766T cells, which did not grow orthotopically. Pathohistological analyses of the orthotopical models revealed an infiltrative growth of almost all tumors into the pancreas; however, the different cell lines gave rise to tumors with different morphological characteristics. All of the resultant tumors were positive for MUC-1 staining indicating their origin from glandular or ductal epithelium, but revealed scattered pan-cytokeratin staining. Transfer of the cytochrome P450 and cytosine deaminase suicide gene, respectively, into the pancreatic cancer cell lines using retroviral vector technology revealed high level infectibility of these cell lines and allowed the analysis of the sensitivity of these cells to the chemotherapeutic drugs ifosfamide and 5-fluorocytosine, respectively. CONCLUSION: These data qualify the cell lines as part of valuable in vitro and in vivo models for the use in defined preclinical studies for pancreas tumor therapy
Cytochrome 2B1 protein expression in PCCWmCMV-transduced and non-transduced parental cell lines.
<p>Total cellular lysates from 8Ă10<sup>5</sup> cells were separated on a 10% polyacrylamide gel under denaturing conditions. After blotting, CYP2B1 protein was detected with a CYP-specific antibody.</p
Molecular alterations of tumor-associated markers in human pancreatic tumor cell lines (based on [27], [28]).
a<p>mutated;</p>b<p>deleted,</p>c<p>wild type,</p>*<p>no consistent information available.</p
Tumor growth development of subcutaneously growing tumors.
<p>5Ă10<sup>6</sup> cells of each pancreatic cell line were subcutaneously injected into the left flank of C.B-17/IcrHsd-<i>Prkcd<sup>scid</sup> Lyst<sup>bg</sup></i> mice at day 0. Visible tumors were measured twice a week with a caliper and size was calculated by the formula âlengthĂwidthĂwidth/2â.</p
Toca 511 gene transfer and 5-fluorocytosine in combination with temozolomide demonstrates synergistic therapeutic efficacy in a temozolomide-sensitive glioblastoma model
Toca 511 (vocimagene amiretrorepvec), an amphotropic retroviral replicating vector (RRV), can successfully and safely deliver a functional, optimized cytosine deaminase (CD) gene to tumors in orthotopic glioma models. This agent, in conjunction with subsequent oral extended-release 5-fluorocytosine (5-FC) (Toca FC), is currently under investigation in patients with recurrent high-grade glioma . Temozolomide (TMZ) with radiation is the most frequently used first-line treatment for patients with glioblastoma, the most common and aggressive form of primary brain cancer in adults. However, subsets of patients with certain genetic alterations do not respond well to TMZ treatment and the overall median survival for patients who respond remains modest, suggesting that combinatorial approaches may be necessary to significantly improve outcomes. We show that in vitro TMZ delays but does not prevent RRV spread, nor interfere with Toca 511+5-FC-mediated cell killing in glioma tumor cells, and in vivo there is no significant hematologic effect from the combination of 5-FC and the clinically relevant dose of TMZ. A synergistic long-term survival advantage is observed in mice bearing an orthotopic TMZ-sensitive glioma after Toca 511 administration followed by coadministration of TMZ and 5-FC. These results provide support for the investigation of this novel combination treatment strategy in patients with newly diagnosed malignant glioma
Pathohistological analyses of tumor tissues.
<p>(<b>2A</b>) Sections of pancreatic tumors derived of the indicated pancreatic cell lines were stained with haematoxylin and eosin. The Hs-766T specimen was dissected from a subcutaneous tumor; all other samples were taken from orthotopically grown tumors. (<b>2B</b>) Different sections of a BxPC-3-derived tumor were subjected to immunohistological analysis with antibodies against Mucin-1 (MUC-1), pan-cytokeratin (Pan-CK), and α-smooth muscle actin (SMA). The black bar represents a length of 53 ”m, except for anti-MUC-1 staining (27 ”m).</p
Cytosine deaminase gene expression in PCCDWmCMVpuro-transduced and in parental cell lines.
<p>Total cellular RNA was isolated from indicated cell lines and mRNA was reverse transcribed using oligo(dT) primers. CD- as well as GAPH-specific gene fragments were amplified using specific primers and separated on an agarose gel showing the expected sizes of âŒ480 bp for CD and âŒ350 bp for GAPDH. The cDNA amount used for PCR amplification was adjusted to yield comparable amounts of the GAPDH gene fragment.</p