Abstract:Hypericin (HYP)-mediated photodynamic therapy (PDT) is a new alternative treatment strategy for colon cancer inducing various cell-death pathways. Apoptotic cell death is the desired cellular fate in cancer cells. Therefore, we investigated the apoptotic pathways by determining apoptosis-related proteins (survivin, caspase-3, caspase-9, Bcl-2, and Bax) at the mRNA level using real-time polymerase chain reaction (qPCR), and the percentage of survivin was determined by survivin ELISA in HT-29 and Caco-2 colon ca… Show more
“…The effect of 0.08 μM HYP on HT-29 and Caco-2 cells showed the highest incidence of apoptosis. These results are in accordance with RT-PCR results for increased caspase-3 activity in HYP treatment groups (Kılıç Süloğlu et al, 2016). Even though slight changes were seen in the percentage of secondary necrosis, they were not statistically significant.…”
Section: Discussionsupporting
confidence: 90%
“…The effective time for HT-29 cells was 24 h after PDT, and 16 h after PDT for Caco-2 cells. The present results suggest that the different gene profiles of these two cells, which have been reported by Kılıç Süloğlu et al (2016), may contribute to alterations in the cell cycle, metabolic activity, and cell death mechanism responses in HT-29 and Caco-2 cells. According to the cell cycle analysis, G2/M cell cycle arrest started 16 h after PDT in Caco-2 cells, whereas in HT-29 cells G2/M arrest started 24 h after PDT.…”
Section: Discussionmentioning
confidence: 65%
“…The fluorescent stainings are also presented in Figures 4-7. The induction of apoptosis after PDT was also supported by DAPI staining (Kılıç Süloğlu et al, 2015) and RT-PCR (caspase-3, survivin, Bcl-2, and Bax expressions) (Kılıç Süloğlu et al, 2016).…”
Hypericin (HYP) is a plant-derived photosensitizer. HYP is preferentially taken up by tumor cells. We designed this study to compare HYP-mediated photodynamic therapy (PDT) in HT-29 and Caco-2 colon cell lines. Cells were treated with 0.04, 0.08, and 0.15 µM HYP concentrations and irradiated. The effect of HYP on metabolic profiles, alterations in lactate dehydrogenase (LDH) leakage, and cell cycle progression was investigated for the first time. Changes in glucose consumption, lactate production, and LDH leakage were analyzed. HYP-induced cell death was quantified by double staining (acridine orange/propidium iodide) and alterations in cell cycle regulation were analyzed with flow cytometry (using propidium iodide). LDH leakage and the number of dead cells were elevated, and glucose consumption and lactate production decreased in a dose-and time-dependent manner. PDT resulted in an induction of apoptosis, mostly at the 0.08 µM HYP concentration. Apoptosis and/or necrosis were increased in the 0.15 µM HYP group. The accumulation of cells in the G2/M phase might account for the growth inhibition in HT-29 and Caco-2 cells with 0.08 µM HYP photoactivation. The observed G2/M arrest suggested that HYP may slow down the growth of colon cancer cells by regulating the cell cycle, leading either to growth inhibition or to initiation of apoptotic pathways.
“…The effect of 0.08 μM HYP on HT-29 and Caco-2 cells showed the highest incidence of apoptosis. These results are in accordance with RT-PCR results for increased caspase-3 activity in HYP treatment groups (Kılıç Süloğlu et al, 2016). Even though slight changes were seen in the percentage of secondary necrosis, they were not statistically significant.…”
Section: Discussionsupporting
confidence: 90%
“…The effective time for HT-29 cells was 24 h after PDT, and 16 h after PDT for Caco-2 cells. The present results suggest that the different gene profiles of these two cells, which have been reported by Kılıç Süloğlu et al (2016), may contribute to alterations in the cell cycle, metabolic activity, and cell death mechanism responses in HT-29 and Caco-2 cells. According to the cell cycle analysis, G2/M cell cycle arrest started 16 h after PDT in Caco-2 cells, whereas in HT-29 cells G2/M arrest started 24 h after PDT.…”
Section: Discussionmentioning
confidence: 65%
“…The fluorescent stainings are also presented in Figures 4-7. The induction of apoptosis after PDT was also supported by DAPI staining (Kılıç Süloğlu et al, 2015) and RT-PCR (caspase-3, survivin, Bcl-2, and Bax expressions) (Kılıç Süloğlu et al, 2016).…”
Hypericin (HYP) is a plant-derived photosensitizer. HYP is preferentially taken up by tumor cells. We designed this study to compare HYP-mediated photodynamic therapy (PDT) in HT-29 and Caco-2 colon cell lines. Cells were treated with 0.04, 0.08, and 0.15 µM HYP concentrations and irradiated. The effect of HYP on metabolic profiles, alterations in lactate dehydrogenase (LDH) leakage, and cell cycle progression was investigated for the first time. Changes in glucose consumption, lactate production, and LDH leakage were analyzed. HYP-induced cell death was quantified by double staining (acridine orange/propidium iodide) and alterations in cell cycle regulation were analyzed with flow cytometry (using propidium iodide). LDH leakage and the number of dead cells were elevated, and glucose consumption and lactate production decreased in a dose-and time-dependent manner. PDT resulted in an induction of apoptosis, mostly at the 0.08 µM HYP concentration. Apoptosis and/or necrosis were increased in the 0.15 µM HYP group. The accumulation of cells in the G2/M phase might account for the growth inhibition in HT-29 and Caco-2 cells with 0.08 µM HYP photoactivation. The observed G2/M arrest suggested that HYP may slow down the growth of colon cancer cells by regulating the cell cycle, leading either to growth inhibition or to initiation of apoptotic pathways.
“…Various families of proteins are involved in the regulation of apoptosis. Bcl2 is the most important family that can regulate apoptosis (56). This family can indirectly regulate caspase activity to control apoptosis and regulate it via heterodimerization of Bcl-2 with Bax (a pro-apoptotic member), resulting in the prevention of mitochondrial changes during apoptosis (42).…”
AIM: The present study investigated the role of redox balance, infl ammation, mitochondrial dysfunction, and apoptosis in Tramadol (Tra)-induced testicular toxicity. METHOD: Twenty-four male Wistar rats were randomly divided into either the control group or the groups receiving different doses of Tra (25, 50, and 75 mg/kg/day, i.p.) for 21 successive days. Testicular tissues were collected for oxidative stress, mitochondrial function, sperm assays and histopathological evaluation. Real-time polymerase chain reaction was performed to evaluate the markers of infl ammation and apoptosis. RESULTS: Tra caused a signifi cant reduction in the sperm count, motility and morphology, while it caused a marked increase in oxidative stress parameters. In addition, Tra induced testicular mitochondrial dysfunction due to the collapse of mitochondrial membrane potential and mitochondrial swelling. It also led to the signifi cant inhibition of anti-apoptotic Bcl-2 expression, besides a signifi cant increase in pro-apoptotic Bax expression. There was a signifi cant increase in the level of tumour necrosis factor-α, interlukin-1β and nuclear factor kappa B. Histopathological degenerative changes were observed in the testis after Tra exposure. CONCLUSIONS: The present results suggest that Tra exposure may lead to reproductive toxicity due to the loss of the antioxidant defence system, mitochondrial dysfunction, and activation of infl ammatory and apoptotic pathways (Tab. 4, Fig. 5, Ref. 63).
“…Unlike the effect of a low dose, a high dose of HYP leads to activation of stress-response pathways that trigger apoptosis or autophagic cell death. If the damage is too severe, the cell dies necrotically [8]. Fig.…”
Background
Colon cancer affects 1.23 million people worldwide and is the third most common malignant disease in men and the second in women. The only curative treatment is surgical resection, but a significant number of patients develop local recurrence or distant metastases. One of the alternative treatment methods for colon cancer is photodynamic therapy (PDT). In recent years, hypericin (HYP) derived from
Hypericum perforatum
has been suggested as a strong candidate photosensitizer for PDT. Our interest is focused on the biophysical changes in colon cancer cells in relation to HYP-mediated PDT.
Results
In this study, HYP-mediated PDT at 0.04, 0.08 or 0.15 μM HYP concentrations was performed in HT-29 colon adenocarcinoma cells and the Electron Paramagnetic Resonance (EPR) spectra of the spin labeled cells were obtained. Plasma membranes are already heterogeneous structures; the presence of cancer cells increased the heterogeneity and also fluidity of the plasma membranes. Therefore, the obtained spectra were evaluated by EPRSIMC program, which provides the calculation of heterogeneous structures up to four spectral components with different fluidity characteristics. Generally, two motional patterns were obtained from calculations and the number of them increased at the highest concentration. As the order parameters of the most populated components compared, an increase was observed depending on the HYP concentration. However, because of the heterogeneous structure of membrane, the order parameters of the less populated components did not exhibit a regular distribution.
Conclusion
After HYP-mediated PDT, concentration dependent changes were observed in the domain parameters indicating an increase in the HYP accumulation.
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