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Background: Non-small cell lung cancer (NSCLC) is the most commonly diagnosed cancer, and radiotherapy (RT) is used for the cancer therapy. RT affects DNA and causes DNA double-strand breaks which are repaired by DNA repair protein ataxia telangiectasia mutated (ATM). RT also affects the mitochondria which is a key player in mediating the radiation response in tumors and removing damaged mitochondria through mitophagy. During mitophagy, PARKIN accumulates on defective mitochondria to mediate the clearance of damaged mitochondria. This study examines the effect of radiation on mitophagy using PARKIN and ATM antibodies on the human NSCLC A549 line. Materials and Methods: A549 cells were treated with 2, 4, 6 and 8 Gy of radiation were analyzed on days 1 and 3 after a single dose of radiotherapy. PARKIN and ATM expressions of A549 cells were examined by using immunohistochemical technique. Results: In the control groups, weak immunoreactivity of ATM and PARKIN was observed on both days 1 and 3. The most intense ATM expression was seen in the 6 and 8 Gy groups after day 1. The most intense PARKIN expression was seen after the days 1 and 3 in the 2 Gy groups. PARKIN immunoreactivity decreased due to increasing radiation dose. Conclusion: It must be considered that mitophagy mechanisms are activated in RT applications. It must be considered that the activation of mitophagy mechanisms in RT and A549 lung cancer cell lines may provide hemostasis in cancer cells. Molecules targeting mitophagy must be developed for use with radiotherapy.

Background: Follicle development takes place under the control of hormonal and environmental stimuli. It suggested that to improve in vitro fertilisation outcomes in poor responders increasing gonadotropin doses be used. Excessive gonadotropin leads to atresia and impairs follicular development, but the molecular mechanisms of follicular atresia remain largely unknown. Recently, it was suggested that autophagy may be an alternative mechanism involved in follicle depletion. Aims: In this study, we aimed to clarify the role of autophagic markers such as light chain (LC) 3B and voltage dependent anion channel 2 (VDAC2) in follicular atresia using the high dose gonadotropin stimulation. Settings and Design: The female 24 BALB/c mice were employed in the present study under the Committee for the Purpose of Control and Supervision of Experiments on Animals guidelines with ethical clearance from the institutional ethical committee. These mice were categorised into four groups, with six rats in each as control and test animals. Materials and Methods: Group 1 (control): no action will be taken. Group 2 (sham): only saline will be applied. Group 3: low-dose gonadotropin Pregnant mare's serum gonadotropin (PMSG) + human chorionic gonadotropin (HCG) will be applied. Group 4: high-dose gonadotropin + HCG will be applied. The animals were sacrificed 48 h after the last injection. For all group samples, both protein and mRNAs of the LC3B and VDAC2 were examined by immunohistochemical and reverse transcription-polymerase chain reaction techniques. Statistical Analysis Used: All variables were analysed using GraphPad Prism 8. Kruskal–Wallis t-test and Mann–Whitney U test were used to compare immunohistochemical results; in addition to this, parametric one-way ANOVA test and Shapiro–Wilk test were applied for quantitative polymerase chain reaction statistics. Results: An increased number of atretic follicles were observed in the high-dose gonadotropin + HCG group. LC3B immunoreactivity of the atretic secondary follicles in the high-dose group is higher than in other groups. The expression of VDAC2 protein in the secondary and Graafian follicles and also VDAC2 mRNA in the ovary were more highly expressed in the control and sham groups. The decrease in VDAC2 mRNA level and immunohistochemical expression was remarkable in the low-dose and high-dose follicle-stimulating hormone groups compared to the control and sham groups. Conclusion: In this study, the increased LC3B and decreased VDAC2 expression, which are autophagy markers, were observed in both the gonadotropins groups, so we suggested that high doses of gonadotropins may cause ovarian atresia.

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