Alteration of p53 and Bax/ Bcl-2 ratio by fotemustine and proton irradiation

Deregulation of apoptosis commonly occurs in melanoma cells and could be a reason for resistance. The effectiveness of different treatments depends on their ability to activate this process. In this study the effects of combined treatments with fotemustine (FM) and proton irradiation on the regulators of apoptosis were analyzed. Sub-confluent HTB140 human melanoma cells were treated with FM (100, 250 µM) 24 h prior to irradiation (12, 16 Gy). Cells were irradiated in the middle of the therapeutic 62 MeV proton spread out Bragg peak. Flow cytometric analysis of apoptosis and the Western blot analysis of apoptotic regulators were performed 6 or 48 h after treatments. Percent of apoptotic nuclei increased after applied treatments, reaching the level of 4 to 41 %. Induction of apoptosis was associated with p53 and Bax up regulation and Bcl-2 down regulation. The obtained results imply that analyzed treatments induce apoptosis through the activation of the mitochondrial apoptotic pathway, with better pro-apoptotic effects achieved by combined treatments

Response of Human HTB140 Melanoma Cells to Conventional Radiation and Hadrons

Conventional radiotherapy with X-and gamma-rays is one of the common and effective treatments of cancer. High energy hadrons, i.e., charged particles like protons and (12)C ions, due to their specific physics and radiobiological advantages are increasingly used. In this study, effectiveness of different radiation types is evaluated on the radio-resistant human HTB140 melanoma cells. The cells were irradiated with gamma-rays, the 62 MeV protons at the Bragg peak and in the middle of the spread-out Bragg peak (SOBP), as well as with the 62 MeV/u (12)C ions. The doses ranged from 2 to 24 Gy. Cell survival and proliferation were assessed 7 days after irradiation, whereas apoptosis was evaluated after 48 h. The acquired results confirmed the high radio-resistance of cells, showing better effectiveness of protons than gamma-rays. The best efficiency was obtained with (12)C ions due to higher linear energy transfer. All analyzed radiation qualities reduced cell proliferation. The highest proliferation was detected for (12)C ions because of their large killing capacity followed by small induction of reparable lesions. This enabled unharmed cells to preserve proliferative activity. Irradiations with protons and (12)C ions revealed similar moderate pro-apoptotic ability that is in agreement with the level of cellular radio-resistance

Response of Human HTB140 Melanoma Cells to Conventional Radiation and Hadrons

Conventional radiotherapy with X-and gamma-rays is one of the common and effective treatments of cancer. High energy hadrons, i.e., charged particles like protons and (12)C ions, due to their specific physics and radiobiological advantages are increasingly used. In this study, effectiveness of different radiation types is evaluated on the radio-resistant human HTB140 melanoma cells. The cells were irradiated with gamma-rays, the 62 MeV protons at the Bragg peak and in the middle of the spread-out Bragg peak (SOBP), as well as with the 62 MeV/u (12)C ions. The doses ranged from 2 to 24 Gy. Cell survival and proliferation were assessed 7 days after irradiation, whereas apoptosis was evaluated after 48 h. The acquired results confirmed the high radio-resistance of cells, showing better effectiveness of protons than gamma-rays. The best efficiency was obtained with (12)C ions due to higher linear energy transfer. All analyzed radiation qualities reduced cell proliferation. The highest proliferation was detected for (12)C ions because of their large killing capacity followed by small induction of reparable lesions. This enabled unharmed cells to preserve proliferative activity. Irradiations with protons and (12)C ions revealed similar moderate pro-apoptotic ability that is in agreement with the level of cellular radio-resistance

The effects of a selected methoxy substituted chalcone in human melanoma cells irradiated with γ-rays

Given the well-established potential of chalcones in modulating the response of cancer cells to therapeutic interventions, coupled with the growing imperative to enhance their biological attributes, the objective of this study was to synthesize a methoxy-substituted chalcone (OCH3) and assess its capacity to amplify the inhibitory effects of radiation in melanoma cells known for their resistance to radiotherapy. The A375 melanoma cells were subjected to a clinically relevant dose of 2 Gy gamma irradiation. OCH3 was employed either as a standalone treatment or in conjunction with irradiation. The obtained results unveiled the substantial radiosensitizing potential of OCH3 within this specific cell line. Our subsequent investigations will be designed to investigate the underlying mechanisms that contribute to the radiosensitizing properties of OCH3. Moreover, we intend to evaluate the efficacy of OCH3 against other types of radioresistant cancer cells. The presented data not only illuminates the enhanced therapeutic possibilities offered by OCH3 but also highlights its potential as a valuable agent in addressing a wider array of challenging malignancies.ICCBIKG 2023 : 2nd International Conference on Chemo and Bioinformatics, September 28-29, 2023; Kragujeva

Radio-protective effect of DMSO glycerol in human non-small cell lung cancer irradiated with gamma rays

Direct effects of radiation affect the DNA molecule, causing DNAdamage and finally cell death. We examined the role of DMSO and glycerol as free-radical scavengers in HTB177 cells irradiated with gamma rays. Direct effects of radiation were estimated through DNA double strand break (DSB) quantification and cell survival. Results of this work revealed that chosen concentration of DMSO exhibit higher protective effect comparing to glycerol.Physical chemistry 2016 : 13th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-30 September 2016

Kinetics of dsb induction and changes in cell cycle regulation in melanoma cells after ionizing radiation

The effects of γ-rays on the DNA level, i.e. formation of double-strand breaks and expression of p21 were studied in vitro on the human HTB 140 melanoma cells. Cells were exposed to the dose range from 2 to 16 Gy. Effects were analyzed 30 min, 2, 6 and 24 h after irradiation. It has been shown that the level of phosphorylated histone H2AX (γH2AX) is time- and dose-dependent, as well as the expression of p21.Physical chemistry 2012 : 11th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 201

Analysis of radiation-induced DNA double strand breaks after exposure to alpha particles: γ-H2AX staining method

The aim of this study was to analyse the γ-H2AX foci in HTB177 non-small lung cancer cells after irradiation with helium ions. Cells were irradiated in three different positions along the widened Bragg peak to follow formation of DNA DSB with respect to LET values. To compare diverse approaches in γ-H2AX foci analysis, we applied the method of foci quantification and total fluorescence intensity measurements. It was shown that helium ions significantly increased the number of γ- H2AX in all irradiated cells. Somewhat higher number of foci was found in samples irradiated within the LET of 24 keV/μm than in those exposed to 4.8 and 37 keV/μm. The same trend was observed after γ-H2AX total fluorescence analysis, showing a good correlation with the results of γ- H2AX foci counting. Further analysis of foci size, as well as colocalization with other DSB repair factors would complement these analyses and give more information about the nature of DNA lesions induced by helium ions

Synthesis and cytotoxic activity of selected dual COX-2 and 5-LOX inhibitors in HeLa and MIA PaCa-2 human cancer cell lines

Among novel cancer chemotherapy approaches, the use of cyclooxygenases (COXs) and lipoxygenases (LOXs) inhibitors represents a promising mean for cancer treatment showing lesser toxicity comparing to the currently used cytotoxic drugs. This study detailed the synthesis of three novel compounds: 1ME, BHTK-AA, and IBU-Ac, each with the capability to concurrently inhibit both COX-2 and 5-LOX. Subsequently, we assessed their effectiveness in inhibiting the proliferation of HeLa cervical and MIA PaCa-2 pancreatic cancer cells. The IC50 values for both examined cell lines were approximately 40 μM, indicating the promising inhibitory potential of the IBU-Ac compound in both types of cancer cells. This finding is positioned to stimulate further investigation into the potential application of IBU-Ac against these particular types of cancers, while also advocating its use in combination with standard anti-cancer protocols, i.e., chemoterapeutics or radiation therapy. The results of this work are also advocating the development and refinement of dual COX-2 and 5-LOX inhibitors, thus improving their efficacy and safety.ICCBIKG 2023 : 2nd International Conference on Chemo and Bioinformatics, September 28-29, 2023; Kragujeva

In vitro biological effects of clonal red wines

This study aimed to determine the phenolic compound content, in vitro antioxidative potential, and cytotoxic effects of four red wine samples: a commercial (V) and three clonal wines (V1, V2, and V3). LC/MS-MS, cyclic voltammetry, and MTT assay techniques were employed for this purpose. Results revealed that all wines were rich in phenolic compounds. Clonal wines outperformed the commercial ones in most phenolic compounds (except myricetin). Notably, V2 and V3 showed the highest levels of gallic acid, catechin, and epicatechin. Among them, V3 exhibited superior antioxidative activity. The MTT assay demonstrated stronger cytotoxic effects of the wine samples on pancreas (Bx-PC3) and colon (HT29) carcinoma cells (47% to 16% and 27% to 7% compared to control, respectively) than on the normal lung fibroblasts (MRC-5) cell line (106% to 77%). It can be concluded that HT29 cells were more sensitive than Bx-PC3 cells. Finally, both clonal and commercial wines serve as valuable sources of polyphenolic compounds, which could have a significant role in preventing cancer and diseases related to oxidative stress.ICCBIKG 2023 : 2nd International Conference on Chemo and Bioinformatics, 28-29 September 2023, Kragujevac, Serbi

Carbon ion beam as inducer of melanoma cell apoptosis

In vitro effect of carbon ions on apoptosis was studied. The human melanoma HTB140 cells were irradiated with the 62 MeV/u 12C ion beam. Percentage of apoptotic cells was evaluated by flow-cytometry and the corresponding apoptotic indexes were calculated. The expression of apoptosis-associated proteins, p53, Bax and Bcl-2 was estimated by Western blot analyses. A dose dependent increase of apoptosis was revealed, with the maximum value of 17 % after irradiation with 16 Gy, and the apoptotic index of 7.7. Pro-apoptotic effects of carbon ion beams were confirmed by the detected changes of key regulators of the mitochondrial apoptotic pathway, the p53 protein expression and the Bax/Bcl-2 ratio