Ferroptosis is an iron-dependent programmed cell death mode that is distinct from other cell death modes, and radiation is able to stimulate cellular oxidative stress and induce the production of large amounts of reactive oxygen radicals, which in turn leads to the accumulation of lipid peroxide and the onset of ferroptosis. In this review, from the perspective of the role of ferroptosis in generating a radiation response following cellular irradiation, the relationship between ferroptosis induced by ionizing radiation stress and the response to ionizing radiation is reviewed, including the roles of MAPK and Nrf2 signaling pathways in ferroptosis, resulting from the oxidative stress response to ionizing radiation, the metabolic regulatory role of the p53 gene in ferroptosis, and regulatory modes of action of iron metabolism and iron metabolism-related regulatory proteins in promoting and inhibiting ferroptosis. It provides some ideas for the follow-up research to explore the specific mechanism and regulatory network of ferroptosis in response to ionizing radiation.

AIMS:Mitochondrial dysfunction is receiving considerable attention due to irreplaceable biological function of mitochondria. Ionizing radiation and tigecycline (TIG) alone can cause mitochondrial dysfunction, playing important role in tumor therapy. However, prior studies fail to investigate combined mechanism of carbon ion irradiation (IR) and TIG on tumor proliferation inhibition. The study aimed to explore the combined effects of both on autophagy and apoptosis.MATERIALS AND METHODS:NSCLC cells A549 and H1299 were treated with carbon ion, TIG, or both. Cell survival rate, autophagy, apoptosis, expression of mitochondrial signaling proteins were determined by clone formation assay, immunofluorescence of LC3B, flow cytometry and western blotting, respectively; ATP content, mitochondrial membrane potential (MMP) and Ca2+ level in mitochondria were used to assessed mitochondrial function.KEY FINDINGS:Results showed IR combined TIG inhibited cells proliferation by increasing apoptosis in both cells and enhancing autophagy in H1299 cells. Additionally, combination treatment induced the most severe mitochondrial dysfunction by sharply reducing ATP, MMP and increasing Ca2+ level of mitochondria. Up-regulation and down-regulation of mitochondrial translation proteins (EF-Tu, GFM1 and MRPS12) expression affected apoptosis and autophagy, while the level of p-mTOR was consistent with their expression in both cell types. In A549 cells, p-AMPK level decreased while p-Akt and p-mTOR increased after combination treatment.SIGNIFICANCE:Overall, our results showed that p-Akt and p-AMPK antagonistically targeted p-mTOR to regulate mitochondrial translation proteins to affect autophagy and apoptosis. Furthermore, this study suggests that combination of carbon ion and TIG is a potential therapeutic option against tumors.

Prostate cancer (PCa) is a malignancy with the highest morbidity rate in 105 countries worldwide and was a major cause of cancer‑associated death in men in 2018. Accumulating evidence suggests that microRNAs (miRNAs/miRs) have important functions in the carcinogenesis of PCa, and may provide novel treatment targets. Previous studies have indicated that miR‑16‑5p is associated with PCa. However, the relevance and importance of miR‑16‑5p in PCa carcinogenesis are still not completely understood. In the current study, we aimed to investigate the role and mechanism of miR‑16‑5p in PCa carcinogenesis. The results showed that miR‑16‑5p was markedly downregulated in PCa cells, and MTS assay, colony formation, flow cytometric analyses demonstrated that miR‑16‑5p inhibited PCa cell survival, regulated cell cycle distribution and induced apoptosis. Moreover, luciferase reporter assay and western blot analysis showed that miR‑16‑5p directly targets AKT3 (AKT serine/threonine kinase 3), which is associated with PCa carcinogenesis, and the effects of the downregulation of AKT3 were similar to the effects of upregulation of miR‑16‑5p in PC‑3 cells. In conclusion, our data clarify that miR‑16‑5p has anticancer functions in PCa cells, and our findings provide experimental evidence to highlight the potential value of miR‑targeting treatment strategies for PCa.

The molecular mechanisms underlying the biological effects of carbon ions are unclear. The aim of this study was to explore the Wnt/beta-catenin pathway in regulating carbon ion (C-12(6+)) radiation-induced cellular toxicity. HLY78 is a Wnt-specific small molecular modulator, whose effects on C-12(6+) radiation-induced damage are mostly unknown. HLY78, in combination with C-12(6+) radiation was investigated on HeLa cell viability, cell cycle progression, DNA damage, and the expression of apoptotic and Wnt-related proteins. C-12(6+) radiation suppressed cell viability in a time-dependent manner, whereas the addition of HLY78 to cells significantly reduced this stress. Moreover, after irradiation with C-12(6+), HeLa cells exhibited increased cell apoptosis, G2/M phase arrest, and a number of gamma-H2AX foci. However, Wnt signaling activation alleviated these effects. Furthermore, when compared with the radiation alone group, supplementation with HLY78 markedly increased the expression of anti-apoptotic and Wnt-related proteins, and significantly decreased the expression of apoptotic proteins. The present results indicated that activation of the Wnt/beta-catenin signaling pathway by HLY78 reduced C-12(6+) radiation-induced HeLa cell dysfunction, suggesting that the Wnt/beta-catenin signaling pathway plays an important role in regulating C-12(6+) radiation-induced cellular toxicity in HeLa cells.

Cervical cancer is the second most common malignant tumour threatening women’s health. In recent years, heavy-ion beam therapy is becoming a newly emerging therapeutic mean of cancer; however, radio-resistance and radiation-induced damage constitute the main obstacles for curative treatment of cervical cancer. Therefore, to identify the radiosensitizers is essential. Here, we investigated the effects of Wnt signalling pathway on the response of 12C6+ radiation in HeLa cells. XAV939, an inhibitor of Wnt signalling pathway, was added two hours before 12C6+ radiation.12C6+ radiation inhibited the viability of HeLa cells in a time-dependent manner, and inhibiting Wnt signalling using XAV939 significantly intensified this stress. Meanwhile, 12C6+ radiation induced a significant increased cell apoptosis, G2/M phase arrest, and the number of γ-H2AX foci. Supplementation with XAV939 significantly increased the effects induced by 12C6+ radiation alone. Combining XAV939 with 12C6+ irradiation, the expression of apoptotic genes (p53, Bax, Bcl-2) was significantly increased, while the expression of Wnt-related genes (Wnt3a, Wnt5a, β-catenin, cyclin D1 and c-Myc) was significantly decreased. Overall, these findings suggested that blockage of the Wnt/β-catenin pathway effectively sensitizes HeLa cells to 12C6+ irradiation, and it may be a potential therapeutic approach in terms of increasing the clinical efficacy of 12C6+ beams.

Radiotherapy is frequently applied for clinically localized prostate cancer while its efficacy could be significantly hindered by radioresistance. MicroRNAs (miRNAs) are important regulators in mediating cellular responses to ionizing radiation (IR), and strongly associate with radiosensitivity in many cancers. In this study, enhancement of radiosensitivity by miR-29b-3p was demonstrated in prostate cancer cell line LNCaP in vitro. Results showed that miR-29b-3p expression was significantly upregulated in response to IR from both X-rays and carbon ion irradiations. Knockdown of miR-29b-3p resulted in radioresistance while overexpression of miR-29b-3p led to increased radiosensitivity (showing reduced cell viability, suppressed cell proliferation and decreased colony formation). In addition, miR-29b-3p was found to directly target Wnt1-inducible-signaling protein 1 (WISP1). Inhibition of WISP1 facilitated the mitochondrial apoptosis pathway through suppressing Bcl-XL expression while activating caspase-3 and poly (ADP-ribose) polymerase (PARP). The results indicated that miR-29b-3p was a radiosensitizing miRNAs and could enhance radiosensitivity of LNCaP cells by targeting WISP1. These findings suggested a novel treatment to overcome radioresistance in prostate cancer patients, especially those with higher levels of the WISP1 expression.

Pladienolide B is a potent cancer cell growth inhibitor that targets the SF3b1 subunit of the spliceosome. There is considerable interest in the compound as a tool to study SF3b1 function in cancer. However, so far little information is available on the molecular mechanism of SF3b1 eliciting apoptosis in cancer cells. Here, we investigated the molecular mechanism of SF3b1 eliciting apoptosis in human cervical carcinoma cells. We demonstrated that inhibition of SF3b1 by pladienolide B inhibited proliferation of HeLa cells at low nanomolar concentrations in a dose- and time-dependent manner. It also induced G2/M phase arrest and significant rise of apoptotic cells. Moreover, it is indicated that inhibition of SF3b1 by pladienolide B induced Tap73/ΔNp73 expression and consequently down-regulated Bax/Bcl-2 ratio, cytochrome c release and caspase-3 expression. Thus, our results showed that SF3b1 plays a pivotal role in cycle arrest, apoptosis induction, and p73 splicing in human cervical carcinoma cells, suggesting that SF3b1 could be used as a potential candidate for cervical cancer therapy.

In spite of carbon ion radiotherapy is a talented modality for malignant tumor patients, the radiation damage of normal tissues adjacent to tumor and the dysfunction of immune system limits therapeutic gain. Protecting immune system against carbon ion radiation-caused damage has the possibility to improve cancer treatment, but it is uncertain whether conventional radioprotective agents play a role in carbon ion radiation. To certify carbon ion caused immune dysfunction and assess the radioprotective effect of melatonin on immune system, animal experiments were performed in radiosensitive BALB/C mice. Here, we observed the bodyweight loss, death and apoptosis, abnormal T-cell distributions in immune system in carbon ion radiated mice. Pretreatment with melatonin could increase the index of thymus and spleen, reduce cell apoptosis in thymus and spleen, and attenuate the carbon ion radiation-caused imbalance of T lymphocytes and disorder of cytokines. These results suggest that melatonin can act as an effective protector against carbon ion radiation-caused immune dysfunction. Furthermore, we also found melatonin restored the activity of the antioxidant enzymes and reduced the level of lipid peroxidation in serum. These data have provided baseline information both for radiation workers and cancer patients to use melatonin as a radioprotector during the carbon ion radiation treatment.

Radiotherapy (RT) is a common treatment for head and neck cancers, but central nervous system function can be impaired by clinical radiation doses. This experimental study evaluated the protective efficacy of the anti-hyperglycaemic/anti-neoplastic agent phenformin against radiation-induced developmental toxicity in zebrafish embryos. Zebrafish embryos pre-treated with 25 μM phenformin 1 h before x-ray irradiation were compared to irradiation-only embryos for mortality, hatching rate, morphology, spontaneous movement, heart beat, larval swimming, activities of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), malondialdehyde content (MDA, a by-product of membrane lipid oxidation), and acetylcholinesterase (AChE) activity. In addition, expression levels of multiple genes related to neural development and apoptosis (sod2, bdnf, ache, p53, bax, and bcl-2) were compared by RT-PCR and associated protein expression levels by western blotting. Pre-treatment with phenformin increased hatching rate, spontaneous movement, heart beat, and larval motor activity, decreased mortality and malformation rate, increased SOD, CAT, and AChE activities, and reduced MDA compared to irradiation-only embryos. The mRNA expression levels of anti-apoptotic sod2, bdnf, ache, and bcl-2 were enhanced while mRNA expression of p53 and pro-apoptotic bax were reduced in the phenformin pre-treatment group. Further, p53, Bax, and γ-H2AX (a biomarker of DNA damage) were downregulated while Bcl-2 and BDNF were upregulated by phenformin pre-treatment. Taken together, this study supports the protective efficacy of phenformin against radiation toxicity in zebrafish embryos by suppressing oxidative stress and ensuing apoptosis.

Emerging evidence indicates that reprogramming of energy metabolism involving disturbances in energy production from a defect in cellular respiration with a shift to glycolysis is a core hallmark of cancer. Alterations in cancer cell energy metabolism are linked to abnormalities in mitochondrial function. Mitochondrial dysfunction of cancer cells includes increased glycolysis, decreased apoptosis, and resistance to radiotherapy. The study was designed for two main points: firstly, to investigate whether exogenous functional mitochondria can transfer into glioma cells and explore the underlying molecular mechanisms from the perspective of endocytosis; secondly, to further verify whether the mitochondrial transplantation is able to rescue aerobic respiration, attenuate the Warburg effect and enhance the radiosensitivity of gliomas. Methods: Mitochondria were isolated from normal human astrocytes (HA) and immediately co-incubated with starved human glioma cells (U87). Confocal microscopy and gene sequencing were performed to evaluate the ability of isolated mitochondria internalization into U87 cells. The interaction between endocytosis and isolated mitochondria transfer were captured by 3D tomographic microscopy and transmission electron microscopy. NAD+, CD38, cADPR and Ca2+ release were determined by commercial kits, western blot, HLPC-MS and Fluo-3 AM respectively. PCR array expression profiling and Seahorse XF analysis were used to evaluate the effect of mitochondrial transplantation on energy phenotypes of U87 cells. U87 cells and U87 xenografts were both treated with mitochondrial transplantation, radiation, or a combination of mitochondrial transplantation and radiation. Apoptosis in vitro and in vivo were detected by cytochrome C, cleaved caspase 9 and TUNEL staining. Results: We found that mitochondria from HA could be transferred into starved U87 cells by simple co-incubation. Starvation treatment slowed the rate of glycolysis and decreased the transformation of NAD+ to NADH in U87 cells. A large amount of accumulated NAD+ was released into the extracellular space. CD38 is a member of the NAD+ glycohydrolase family that catalyzes the cyclization of extracellular NAD+ to intracellular cADPR. cADPR triggered release of Ca2+ to promote cytoskeleton remodeling and plasma membrane invagination. Thus, endocytosis involving isolated mitochondria internalization was mediated by NAD+-CD38-cADPR-Ca2+ signaling. Mitochondrial transfer enhanced gene and protein expression related to the tricarboxylic acid (TCA) cycle, increased aerobic respiration, attenuated glycolysis, reactivated the mitochondrial apoptotic pathway, inhibited malignant proliferation of U87 cells. Isolated mitochondria injected into U87 xenograft tumors also entered cells, and inhibited glioma growth in nude mice. Mitochondrial transplantation could enhance the radiosensitivity of gliomas in vitro and in vivo. Conclusion: These findings suggested that starvation-induced endocytosis via NAD+-CD38-cADPR-Ca2+ signaling could be a new mechanism of mitochondrial transplantation to rescue aerobic respiration and attenuate the Warburg effect. This mechanism could be a promising approach for radiosensitization.

Irradiation (IR) can be used to treat cancer by inducing complex and irreparable DNA damage in the cancer cells, which may lead to their apoptotic death. However, little is known about the molecular mechanism of this DNA damage. Here, the non-small-cell lung cancer cell line A549 was treated with either X-ray or carbon ion combined with bleomycin (BLM). The cell survival rate, frequency of double-strand breaks (DSBs), dynamic changes in γH2AX, and p53 binding protein 1 (53BP1), and protein expression of Ku70, Rad51, and XRCC1 were determined by the clone formation assay, agarose gel electrophoresis, immunofluorescence, and western blot analysis. The results showed that the most obvious complex DSBs occurred in the carbon IR + BLM group. The number of γH2AX and 53BP1 foci in the 0.5 hr X-ray IR + BLM group was the highest (p < 0.001) among all the groups. γH2AX foci were detected in the nucleus at 0.5, 1, 2, and 4 hr, but were distributed throughout the cell at 6 hr after IR in the carbon ion IR + BLM group. The expression of Ku70 increased and XRCC1 decreased at 2 and 6 hr after IR. Our data indicate that a DNA damage frequency of 13.4/Mbp is caused by clustered DNA damage and further show a correlation between γH2AX, 53BP1, and XRCC1 levels and the extent of DNA damage. The results of this study provide insights into DNA damage recognition and a rationale for the clinical use of radiotherapy.

OBJECTIVE:To investigate the effect of Yishengukang decoction on the expression of the metabolic bone markers, bone-specific alkaline phosphatase (BAP), carboxyterminal propeptide of type Ⅰ procollagen (PICP), and arboxyterminal cross-linked telepeptide of type Ⅰ collagen (ICTP), in cancer patients with bone metastasis. METHODS:Patients (n = 180) were divided into three groups: (a) bone metastasis patients treated with Yishengukang and pamidronate disodium injection (treatment group, n = 60); (b) bone metastasis patients treated with pamidronate disodium injection alone (control group, n = 60); (c) cancer patients without metastatic bone lesion (non-bone metastasis group, n = 60). Serum levels of the metabolic markers BAP, PICP, and ICTP were detected by enzyme-linked immunosorbent assay pre- and post-therapy. RESULTS:A significant decrease in serum BAP level was observed in the treatment group compared with the control group. However there were no significant differences in serum levels of PICP and ICTP before or after treatment compared with the control group. CONCLUSION:Yishengukang decoction combined with pamidronate disodium injection reduced serum BAP level to a greater extent that pamidronate disodium injection alone. Furthermore, the combined therapy was more beneficial in regulating imbalanced bone metabolism after bone metastasis, and may represent the molecular mechanism underpinning the effects of Yishengukang decoction.

Background: Hepatic ischemia/reperfusion (I/R) injury is a disaster common critical event which frequently occurs in a variety of clinical scenarios. To investigate the protective effect of Wy14643 (WY) precondition against hepatic ischemia/ reperfusion (I/R) injury in rats and its potential mechanism. Methods: Thirty Sprague–Dawley male rats weighing 220-250 g were randomly divided into three groups (n=10) including the sham-operated +saline group (Sham), the ischemic-reperfusion+ vehicle (IRI), and the WY14643 preconditioning group (WY). The three groups were pretreated with saline, ethanol and WY, at 1 h before ischemia with a concentration of 10 mg/kg , respectively. Hepatic ischemia-reperfusion (I/R) was induced by clamping blood supply to the left lateral and median lobes of the liver for 90 min. Blood samples and liver tissues were obtained at the end of 4h reperfusion. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) were measured. The histological changes of hepatic tissues were examanied by HE staining. The expression of interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) were detected by ELISA and RT-PCR. Moreover, the expression of TLR-4 , I-, Myd88, p65 and PPAR- were detected by western blotting. Result: After 4 h reperfusion, compared with the IRI group, the liver dysfunction (ALT, AST and LDH), damage score, the expression of TNF-α , IL-6, and IL-1β, the protein expression level of TLR4, Myd88, the phosphorylation level of IκB- and p65 in the WY group was significantly decreased (all P

Background: Tubeimoside I (TBMS1), a triterpenoid saponin, isolated from the tubers of Bolbostemma paniculatum, showed potent antitumor and antitumor-promoting effects. The objective of this study is to investigate the role of mitochondria and mitochondria cytochrome c in TBMS1-mediated apoptosis of human cervical carcinoma HeLa cell line. Methods: Viability of HeLa cells was measured by MTT assay. Apoptotic induction by TBMS1 was determined by fluorescence microscopy, flow cytometry and gel electrophoresis of fragmented DNA. Mitochondrial transmembrane potential (Δψm) was assayed by flow cytometry. Cytochrome c (Cyt c) was detected by Western blotting. Results: The results showed that Cyclosporin A (CsA) partly protected HeLa cells from growth inhibitory effect of TBMS1, and partly countered the ability of TBMS1 to rapidly induce apoptosis in HeLa cells, and that TBMS1 decreased Δψm and induced Cyt c release by a mechanism inhibited by CsA, and that TBMS1 induced apoptosis of HeLa cells dose-dependently in accordance with increase of cytosolic Cyt c. Conclusions: TBMS1 opens the permeability transition (PT) pore, thereby decreasing Δψm, releasing Cyt c from mitochondria, and further causing a series of events consistent with established mechanistic models of apoptosis.