In vitro validation of helium ion irradiations as a function of linear energy transfer in radioresistant human malignant cells.

Purpose: Based on considerable interest to enlarge the experimental database of radioresistant cells after their irradiation with helium ions, HTB140, MCF-7 and HTB177 human malignant cells are exposed to helium ion beams having different linear energy transfer (LET).

Materials And Methods: The cells are irradiated along the widened 62 MeV/u helium ion Bragg peak, providing LET of 4.9, 9.

Unveiling Anticancer Potential of COX-2 and 5-LOX Inhibitors: Cytotoxicity, Radiosensitization Potential and Antimigratory Activity against Colorectal and Pancreatic Carcinoma.

Apart from cytotoxicity, inhibitors of the COX-2 enzyme have demonstrated additional effects important for cancer treatment (such as radiosensitization of tumor cells and cell antimigratory effects); however, the relationship between the inhibition of other inflammation-related enzyme 5-LOX inhibitors and anticancer activity is still not well understood. In our study, the cytotoxicity of thirteen COX-2 and 5-LOX inhibitors previously presented by our group (-) was tested on three cancer cell lines (HCT 116, HT-29 and BxPC-3) and one healthy cell line (MRC-5). Compounds , , and showed moderate cytotoxicity, but good selectivity towards cancer cell lines.

Cytotoxic activity and influence on acetylcholinesterase of series dinuclear platinum(II) complexes with aromatic nitrogen-containing heterocyclic bridging ligands: Insights in the mechanisms of action.

Herein, the stability, lipophilicity, in vitro cytotoxicity, and influence on acetylcholinesterase of five dinuclear platinum(II) complexes with the general formula [{Pt(en)Cl}(μ-L)] (L is a different aromatic nitrogen-containing heterocyclic bridging ligands pyrazine (pz, Pt1), pyridazine (pydz, Pt2), quinoxaline (qx, Pt3), phthalazine (phtz, Pt4) and quinazoline (qz, Pt5), while en is bidentate coordinated ethylenediamine) were evaluated. The most active analyzed platinum complexes induced time-dependent growth inhibition of A375, HeLa, PANC-1, and MRC-5 cells. The best efficiency was achieved on HeLa and PANC-1 cells for Pt1, Pt2, and Pt3 at the highest concentration, while Pt1 was significantly more potent than cisplatin at a lower concentration.

DNA double-strand breaks in cancer cells as a function of proton linear energy transfer and its variation in time.

Purpose: The complex relationship between linear energy transfer (LET) and cellular response to radiation is not yet fully elucidated. To better characterize DNA damage after irradiations with therapeutic protons, we monitored formation and disappearance of DNA double-strand breaks (DNA DSB) as a function of LET and time. Comparisons with conventional γ-rays and high LET carbon ions were also performed.

A radiobiological study of carbon ions of different linear energy transfer in resistant human malignant cell lines.

Purpose: Analysis of elimination of four human radioresistant malignant cell lines to mono-energetic and non mono-energetic incoming carbon ion beams, characterized by different linear energy transfer (LET) qualities is performed. Comparisons with protons from the middle of the therapeutic spread out Bragg peak (SOBP) and reference γ-rays are also included.

Materials And Methods: HTB140 cells were irradiated at five positions, with different LET, along the 62 MeV carbon pristine Bragg peak.

Biological outcomes of γ-radiation induced DNA damages in breast and lung cancer cells pretreated with free radical scavengers.

Purpose: Investigation of effects on DNA of γ-irradiated human cancer cells pretreated with free radical scavengers is aimed to create reference data which would enable assessment of the relative efficiency of high linear energy transfer (LET) radiations used in hadron therapy, i.e. protons and carbon ions.

Carbon ions of different linear energy transfer (LET) values induce apoptosis & G2 cell cycle arrest in radio-resistant melanoma cells.

Background & Objectives: The main goal when treating malignancies with radiation is to deprive tumour cells of their reproductive potential. One approach is to induce tumour cell apoptosis. This study was conducted to evaluate the ability of carbon ions ( [12] C) to induce apoptosis and cell cycle arrest in human HTB140 melanoma cells.

Comparison of human lung cancer cell radiosensitivity after irradiations with therapeutic protons and carbon ions.

The aim of this study was to investigate effects of irradiations with the therapeutic proton and carbon ion beams in two non-small cell lung cancers, CRL5876 adenocarcinoma and HTB177 large cell lung carcinoma. The DNA damage response dynamics, cell cycle regulation, and cell death pathway activation were followed. Viability of both cell lines was lower after carbon ions compared to the therapeutic proton irradiations.

The impact of autophagy on cell death modalities in CRL-5876 lung adenocarcinoma cells after their exposure to γ-rays and/or erlotinib.

In most patients with lung cancer radiation treatment is used either as single agent or in combination with radiosensitizing drugs. However, the mechanisms underlying combined therapy and its impact on different modes of cell death have not yet been fully elucidated. We aimed to examine effects of single and combined treatments with γ-rays and erlotinib on radioresistant CRL-5876 human lung adenocarcinoma cells with particular emphasis on cell death.

Radiation dose determines the method for quantification of DNA double strand breaks.

Ionizing radiation induces DNA double strand breaks (DSBs) that trigger phosphorylation of the histone protein H2AX (γH2AX). Immunofluorescent staining visualizes formation of γH2AX foci, allowing their quantification. This method, as opposed to Western blot assay and Flow cytometry, provides more accurate analysis, by showing exact position and intensity of fluorescent signal in each single cell.

Radiosensitivity of human ovarian carcinoma and melanoma cells to γ-rays and protons.

Introduction: Proton radiation offers physical advantages over conventional radiation. Radiosensitivity of human 59M ovarian cancer and HTB140 melanoma cells was investigated after exposure to γ-rays and protons.

Material And Methods: Irradiations were performed in the middle of a 62 MeV therapeutic proton spread out Bragg peak with doses ranging from 2 to 16 Gy.

Proton inactivation of melanoma cells enhanced by fotemustine.

Response of human HTB140 melanoma cells to proton irradiation in combination with fotemustine (FM) was investigated. Effects of these agents were analysed on cell proliferation and induction of apoptosis. Cells pretreated with 100- or 250-µM of FM were irradiated in the middle of the therapeutic 62-MeV proton spread-out Bragg peak, with a dose of 16 Gy.