Cellular Radiosensitivity of Soft Tissue Sarcoma.

Currently, all soft tissue sarcomas (STS) are irradiated by the same regimen, disregarding possible subtype-specific radiosensitivities. To gain further insight, cellular radiosensitivity was investigated in a panel of sarcoma cell lines. Fourteen sarcoma cell lines, derived from synovial sarcoma, leiomyosarcoma, fibrosarcoma and liposarcoma origin, were submitted to clonogenic survival assays.

Micro cone beam computed tomography for sensitive assessment of radiation-induced late lung toxicity in preclinical models.

Background And Purpose: Preclinical models are much needed to assess the effect of novel radio-sensitizers or mitigators on radiation dose limiting lung toxicity. Albeit showing radiation-induced lung pathologies, current mouse models lack the sensitivity to do so. Using micro image-guided radiotherapy (µIGRT) techniques, we aimed to establish murine models which enable the sensitive detection of lung damage aggravation and characterized functional, radiological and histological responses.

Blood and lymphatic microvessel damage in irradiated human skin: The role of TGF-β, endoglin and macrophages.

Background And Purpose: Microvascular damage is an important component of late radiation-induced morbidity. In our pre-clinical models, we demonstrated that repair of vessel injury is dependent on proper endoglin-mediated transforming growth factor-beta (TGF-β) signalling and that it can be affected by infiltrating macrophages. We now wanted to extend these findings in irradiated patients, using skin as a model system, and assess whether bisphosphonates could modulate the response.

Thalidomide ameliorates inflammation and vascular injury but aggravates tubular damage in the irradiated mouse kidney.

Purpose: The late side effects of kidney irradiation include vascular damage and fibrosis, which are promoted by an irradiation-induced inflammatory response. We therefore treated kidney-irradiated mice with the anti-inflammatory and angiogenesis-modulating drug thalidomide in an attempt to prevent the development of late normal tissue damage and radiation nephropathy in the mouse kidney.

Methods And Materials: Kidneys of C57Bl/6 mice were irradiated with a single dose of 14 Gy.

NAD⁺ depletion by APO866 in combination with radiation in a prostate cancer model, results from an in vitro and in vivo study.

Background: APO866 is a highly specific inhibitor of nicotinamide phosphoribosyltransferase (NAMPT), inhibition of which reduces cellular NAD(+) levels. In this study we addressed the potential of NAD(+) depletion as an anti-cancer strategy and assessed the combination with radiation.

Methods: The anticipated radiosensitizing property of APO866 was investigated in prostate cancer cell lines PC3 and LNCaP in vitro and in PC3 xenografts in vivo.

Endoglin haploinsufficiency attenuates radiation-induced deterioration of kidney function in mice.

Background And Purpose: Endoglin is a transforming growth receptor beta (TGF-β) co-receptor, which plays a crucial role in the development of late normal tissue damage. Mice with halved endoglin levels (Eng(+/-) mice) develop less inflammation, vascular damage and fibrosis after kidney irradiation compared to their wild type littermates (Eng(+/+) mice). This study was aimed at investigating whether reduced tissue damage in Eng(+/-) mice also results in superior kidney function.

The TGF-β co-receptor endoglin regulates macrophage infiltration and cytokine production in the irradiated mouse kidney.

Background And Purpose: We previously showed that mice with reduced levels of the transforming growth factor-beta (TGF-β) co-receptor endoglin (Eng(+/-) mice) develop less fibrosis and vascular damage after kidney irradiation than their wild type (Eng(+/+) mice) littermates; however, the underlying mechanism was unclear. Results from current studies suggest that this occurs via modulation of the radiation-induced inflammatory response.

Materials And Methods: Kidneys of Eng(+/+) and Eng(+/-) mice were irradiated with 16Gy.

ALK1 heterozygosity delays development of late normal tissue damage in the irradiated mouse kidney.

Background And Purpose: Activin receptor-like kinase 1 (ALK1) is a transforming growth factor β (TGF-β) receptor, which is mainly expressed in endothelial cells regulating proliferation and migration in vitro and angiogenesis in vivo. Endothelial cells also express the co-receptor endoglin, which modulates ALK1 effects on endothelial cells. Our previous studies showed that mice with reduced endoglin levels develop less irradiation-induced vascular damage and fibrosis, caused by an impaired inflammatory response.

Endoglin haploinsufficiency reduces radiation-induced fibrosis and telangiectasia formation in mouse kidneys.

Background And Purpose: Endoglin is a transforming growth factor beta (TGF-beta) co-receptor mainly expressed in dividing endothelial cells. It regulates cell proliferation and survival and is upregulated at sites of vessel repair. Mutations in endoglin have been linked to the vascular disease hereditary hemorrhagic telangiectasia (HHT).

Radiation-induced activation of TGF-beta signaling pathways in relation to vascular damage in mouse kidneys.

The purpose of this study was to investigate the long-term effects of radiation-induced alterations in TGF-beta signaling pathways with respect to the development of vascular damage in the irradiated kidney. Total RNA was isolated from mouse kidneys at 1-30 weeks after irradiation, and quantitative real-time PCR analyses were performed for TGF-beta receptors (ALK1, ALK5, endoglin), downstream mediators (Smad7, CTGF), and downstream targets (PAI-1 and Id-1). Expression of endoglin and Smad7 protein as well as nucleo-cytoplasmic distribution of phospho Smad 2/3 and phospho Smad 1/5 was analyzed by immunohistochemistry.

In vivo bioluminescence imaging of locally disseminated colon carcinoma in rats.

Animal tumour models using orthotopic tumours for the evaluation of cancer therapies are of greater clinical relevance than subcutaneous models, but they also pose greater difficulties for measuring tumour size and quantifying response to treatment. In this study, we used noninvasive bioluminescence imaging to monitor the intraperitoneal growth of luciferase-transfected CC531 colorectal cells in adult WAG/RIJ rats. The bioluminescence signal correlated well with post-mortem assessment of tumour load by visual inspection of the peritoneal cavity at specific follow-up times.

Pharmacokinetics and pharmacodynamics of cisplatin after intraoperative hyperthermic intraperitoneal chemoperfusion (HIPEC).

Background: HIPEC is a new treatment modality for abdominal cancers that combines cytoreductive surgery with Hyperthermic, Intraoperative Peritoneal Chemotherapy, followed by systemic chemotherapy. A significant survival benefit has been shown for HIPEC compared with systemic therapy alone. However, it is not clear what is the contribution of i.

Overexpression of the BCRP/MXR/ABCP gene in a topotecan-selected ovarian tumor cell line.

Topotecan- or mitoxantrone-selected cell lines (T8 and MX3, respectively), derived from the human IGROV1 ovarian cancer cell line, were resistant to the topoisomerase I inhibitors topotecan, SN-38 (the active metabolite of irinotecan), and 9-aminocamptothecin, as well as to the topoisomerase II drug mitoxantrone. In both resistant cell lines, decreased accumulation of topotecan and mitoxantrone was observed, caused by enhanced energy-dependent efflux of the drugs involved. In both cell lines, we found that the breast cancer resistance protein/mitoxantrone resistance/placenta-specific ATP binding cassette (BCRP/MXR/ABCP) gene was overexpressed.

In vitro antagonistic cytotoxic interactions between platinum drugs and taxanes on bone marrow progenitor cell CFU-GM.

We have designed and used an in vitro bone marrow cell culturing system for investigating pharmacodynamic interactions between platinum anti-cancer drugs and taxanes. With this system, in which the bone marrow progenitor cell CFU-GM is proliferating and differentiating into granulocytes and monocytes, we could show a strong antagonistic cytotoxicity of the combination carboplatin and Taxotere, in three different schedules, and of the combination cisplatin and Taxol, in two out of the three schedules tested. Modulation of intracellular platinum drug accumulation in granulocytes and monocytes does not seem to be a plausible explanation for the observed antagonism.

The formation and repair of cisplatin-DNA adducts in wild-type and cisplatin-resistant L1210 cells: comparison of immunocytochemical determination with detection in isolated DNA.

We have studied the formation and repair of cisplatin-DNA adducts in wild-type mouse leukemia L1210/0 cells and in the sublines L1210/2 and L1210/5, which differ in cisplatin sensitivity. In a colony-formation assay these sublines were 9- and 22-fold more resistant compared to L1210/0, respectively. Cisplatin-induced DNA modification was studied at the cellular level by immunocytochemistry with antiserum NKI-A59 raised against cisplatin-treated DNA.

Comparison of 32P-postlabeling and HPLC-FD analysis of DNA adducts in rats acutely exposed to benzo(a)pyrene.

DNA adduct analysis is often used for biomonitoring individuals exposed to polycyclic aromatic hydrocarbons (PAH). The 32P-postlabeling assay is routinely applied to study the formation of aromatic bulky adducts, but cannot positively identify individual adduct types. Recently, an HPLC assay with fluorescence detection (HPLC-FD) was developed which was sufficiently sensitive to detect adducts formed by benzo[a]pyrene (B[a]P) diolepoxide isomers [(+/-)anti- and (+/-)syn-BPDE] in occupationally exposed subjects (Rojas et al.

Formation of interaction products of carboplatin with DNA in vitro and in cancer patients.

Binding of the cytostatic drug carboplatin to DNA was studied in solution, in RIF-1 and CHO cell lines and in human buccal cells after in vitro or in situ drug exposure. Results were compared with DNA adduction by cisplatin. The rate of binding in solution, determined by atomic absorption spectroscopy, was 35 times lower for carboplatin than for cisplatin.

Antibodies against cisplatin-modified DNA and cisplatin-modified (di)nucleotides.

Cytotoxic effects of cis-diamminedichloroplatinum-(II) (cis-DDP) are thought to be mediated by binding to DNA. Studies on binding of cis-DDP to cellular DNA rely heavily on the availability of specific antibodies. We therefore raised and characterized four rabbit antisera: one against cis-DDP-modified DNA (antiserum NKI-A59) and three others against the cis-DDP-modified (di)nucleotides cis-Pt(NH3)2d(pApG) (NKI-A68), cis-Pt(NH3)2d(GMP)2 (NKI-A10), and Pt(NH3)3dGMP (NKI-A39).

Correlation between cell killing by cis-diamminedichloroplatinum(II) in six mammalian cell lines and binding of a cis-diamminedichloroplatinum(II)-DNA antiserum.

The relationship between cell killing and the binding of the anticancer drug cis-diamminedichloroplatinum(II) (cis-DDP) to DNA was studied in six mammalian cell lines. Two of the human cell lines (COV413B) were of the same origin, comprising one sensitive to cis-DDP and the other with induced resistance to the drug. The four other lines, two rodent (RIF-1, Chinese hamster ovary) and two human (A2780, A1847), were unrelated.

Cellular distribution of cis-diamminedichloroplatinum(II)-DNA binding in rat dorsal root spinal ganglia: effect of the neuroprotecting peptide ORG.2766.

The in situ binding of the anticancer drug cis-diamminedichloroplatinum(II) (cisDDP) to DNA was studied in the rat dorsal root spinal ganglion (DRG), using an antiserum against cisDDP-modified calf thymus DNA in a quantitative immunocytochemical assay. Rats received a dose of cisDDP (1 mg/kg), two times a week, up to a cumulative dose of 15 mg/kg (group I) or 34 mg/kg (group II). Rats of group III were given a single dose of 15 mg/kg.

Monitoring of interaction products of cis-diamminedichloroplatinum(II) and cis-diammine(1,1-cyclobutanedicarboxylato)platinum(II) with DNA in cells from platinum-treated cancer patients.

The formation and stability of interaction products between the anti-cancer drug cis-diamminedichloroplatinum(II) (cis-DDP) and DNA were studied in buccal epithelial and urinary cells from ten cancer patients who received cis-DDP-based therapy. Buccal cells were collected 1 h before and 1-2 h after i.v.

Immunocytochemical detection of interaction products of cis-diamminedichloroplatinum(II) and cis-diammine(1,1-cyclobutanedicarboxylato)platinum(II) with DNA in rodent tissue sections.

Calf thymus DNA was modified in vitro by cis-diamminedichloroplatinum(II) (cisDDP), complexed with methylated bovine serum albumin and used to immunize rabbits. The anti-cisDDP-DNA antiserum obtained was applied in a double peroxidase-antiperoxidase staining procedure to localize cisDDP-DNA and cis-diammine(1,1-cyclobutanedicarboxylato)platinum(II) (CBDCA)-DNA interaction products in cryostat tissue sections of mice and rats. Rats received cisDDP (0-10 mg/kg) and were killed after 24 h.

Enhanced repair of O6-methylguanine in liver DNA of rats pretreated with phenobarbital, 2,3,7,8-tetrachlorodibenzo-p-dioxin, ethionine, or N-alkyl-N-nitrosoureas.

Rats were pretreated for a number of weeks with the liver tumour promoters phenobarbital and 2,3,7,8-tetrachlorodibenzo-p-dioxin, the direct alkylating agents N-ethyl-N-nitrosourea and N-methyl-N-nitrosourea, and the hepatocarcinogens ethionine and diethylnitrosamine. A subsequent challenge with a single, low dose of radioactively labelled dimethylnitrosamine was given to assay the capacity of the liver for O6-methylguanine repair. Pretreatment with 0.

The induction of chromosomal damage in rat hepatocytes and lymphocytes. II. Alkylation damage and repair of rat-liver DNA after diethylnitrosamine, dimethylnitrosamine and ethyl methanesulphonate in relation to clastogenic effects.

Rat-liver DNA alkylation by diethylnitrosamine (DEN), dimethylnitrosamine (DMN) and ethyl methanesulphonate (EMS) was studied in an attempt to relate chromosome-damaging effects of these agents (the formation of micronuclei in hepatocytes; see preceding paper) to specific alkylation patterns. No correlation was observed between the induction of micronuclei and liver DNA N-alkylation, measured as 3- and 7-alkyl-purines. O6-Alkylguanine is probably not involved in micronucleus induction because it is lost from DNA too rapidly to explain the much more persistent clastogenic effects.

Persistence and accumulation of (potential) single-strand breaks in liver DNA of rats treated with ethyl methanesulphonate.

In vivo alkylation of DNA leads to DNA fragmentation in alkaline sucrose gradients. In a previous paper (Chem.-Biol.