Kaihua Ji

Genomic instability in adult men involved in processing electronic waste in Northern China

BACKGROUNDnManaging and recycling electronic waste (e-waste), while useful and necessary, has resulted in significant contamination of several environments in China. The area around Tianjin, China has become one of the worlds largest e-waste disposal centers, where electronics are processed by manually disassembly or burning, which can result in serious exposure of workers to a multitude of toxicants.nnnOBJECTIVEnThe present study assessed potential genomic damage in workers involved in recycling e-waste.nnnMETHODSnTo detect cytogenetic and DNA damage, chromosomal aberrations (CA), cytokinesis blocking micronucleus (CBMN) and the comet assay were performed. Concentrations of some trace elements, markers of oxidative stress and polychlorinated biphenyls (PCBs) in whole blood or serum were measured, and relationships among the markers described above, age, and duration of exposure were analyzed. The profiles of expression of genes in lymphocytes in peripheral blood were assessed to determine the status of the regulation of genes involved in genome stability.nnnRESULTSnConcentrations of 28 PCB congeners in the whole blood of the exposed group were significantly (P<0.001) greater than those in the control individuals. Frequency of CA (8.01%) and CBMN (26.3‰) in lymphocytes and the level of DNA damage in the lymphocytes and spermatozoa of the exposed men were also significantly (P<0.0001) greater than those of the controls. There were significant relationships between CA, CBMN, DNA damage and duration of exposure. Concentrations of malondialdehyde (MDA) and lead (Pb) in the blood serum were significantly greater, but activities of superoxide dismutase (SOD), glutathione (GSH) and concentrations of calcium (Ca) and magnesium (Mg) were lower in the serum of the exposed men. MDA, Pb, Ca and Mg were associated with the duration of exposure to handling e-waste. In males involved in handling of e-waste, there were 13 genes - ATM, ATR, ABL1, CHEK1, CHEK2, GADD45A, CDK7, GTSE1, OGG1, DDB1, PRKDC, XRCC1 and CCNH - for which expression of mRNA was up-regulated and 7 genes - BRCA1, GTF2H1, SEMA4A, MRE11A, MUTYH, PNKP and RAD50 - for which the expression of mRNA was down-regulated.nnnCONCLUSIONSnA strong correlation between indicators of damage of DNA, which could result in instability of the genome, and duration of processing e-waste was observed. If proper procedures are not followed, there are significant risks to the health of the individuals involved in such activities.

Cytogenetics data in adult men involved in the recycling of electronic wastes

In this data article, 146 villagers (exposed group) were randomly selected from the workers who involved in the e-wastes recycling directly as a daily job in Tianjin. Control group, including 121 villagers, came from another town without e-waste disposal sites. Chromosomal aberrations (CA) and cytokinesis blocking micronucleus (CBMN) were performed to detect the cytogenetic effect for each subject. DNA damage was detected using comet assay; the DNA percentage in the comet tail (TDNA%), tail moment (TM), and Olive tail moment (OTM) were recorded to describe DNA damage to lymphocytes and spermatozoa. Routine semen analysis, spermatozoa motility and morphology were analyzed. The RT2Profiler PCR array was used to measure levels of expression of 84 genes related to quality of DNA. It showed significant relationships between CA, CBMN, DNA damage and exposure time in exposure subjects. The alteration of sperm motility rate, abnormality rate and total sperm counts had association with exposure time and age.

Identification of Circular RNAs Altered in Mouse Jejuna After Radiation.

Background/Aims: Circular RNAs (circRNAs) make up a large class of non-coding RNAs and play important roles in a variety of diseases, including nervous system diseases and cancers. The intestinal epithelium is sensitive to ionizing radiation, radiotherapy of abdominal or pelvic tumors or nuclear accident exposure can lead to high radiation toxicity, which can result in radiation-induced intestinal injury. The goal of this present study was to analyze the potential roles of circRNAs in radiation-induced intestinal injury. Methods: Mice were divided into two groups: control group and irradiated group. Irradiated group was 3.5 days after 14Gy abdominal irradiation (ABI) group. We started with RNA-seq of circRNA changes in mouse jejuna after radiation and validated by RT-PCR in the following experimental. miRNAs targeted mRNAs were predicted using proprietary software based on target scan and Miranda. The network of circRNA-miRNA-mRNA was illustrated by cytoscape software. Results: 2751 circRNAs were detected in the two groups. At day 3.5 post-radiation, 42 and 48 circRNAs were found to be significantly upregulated and downregulated, respectively, compared to the control (p≤0.05, Fold Change ≥2). Further, the altered expression of 10 circRNAs (chr18: 35610871-35613502+, chr15: 95864225-95894541+, chr3: 96041338-96042928-, chr5: 64096979-64108263+, chr19: 16705875-16710941-, chr5: 134491893-134500149-, chr19: 42562552-42564341+, chr5: 32640331-32664400+, chr3: 72958113-72960367- and chr8: 79343654-79372364-) were verified by RT-PCR. Compared the miRNA-targeted mRNAs with our mRNAs sequencing data, we found 14 upregulated circRNA-targeted mRNAs were also unregulated and 22 downregulated circRNAs-targeted mRNAs were also downregulated. Gene ontology and KEGG pathway analyses indicated the predicted genes were mainly involved in the MAPK signaling pathway. Conclusions: This study reveals that expression of circRNAs was altered in the jejuna of mice post-irradiation and provides a resource for the study of circRNAs in radiation-induced intestinal injury and repair.

Analysis of changes to lncRNAs and their target mRNAs in murine jejunum after radiation treatment

LncRNAs have been reported to play an important role in various diseases. However, their role in the radiation‐induced intestinal injury is unknown. The goal of the present study was to analyse the potential mechanistic role of lncRNAs in the radiation‐induced intestinal injury. Mice were divided into two groups: Control (non‐irradiated) and irradiated. Irradiated mice were administered 14 Gy of abdominal irradiation (ABI) and were assessed 3.5 days after irradiation. Changes to the jejuna of ABI mice were analysed using RNA‐Seq for alterations to both lncRNA and mRNA. These results were validated using qRT‐PCR. LncRNAs targets were predicted based on analysis of lncRNAs‐miRNAs‐mRNAs interaction. 29 007 lncRNAs and 17 142 mRNAs were detected in the two groups. At 3.5 days post‐irradiation, 91 lncRNAs and 57 lncRNAs were significantly up‐ and downregulated respectively. Similarly, 752 mRNAs and 400 mRNAs were significantly up‐ and downregulated respectively. qRT‐PCR was used to verify the altered expression of four lncRNAs (ENSMUST00000173070, AK157361, AK083183, AK038898) and four mRNAs (Mboat1, Nek10, Ccl24, Cyp2c55). Gene ontology and KEGG pathway analyses indicated the predicted genes were mainly involved in the VEGF signalling pathway. This study reveals that the expression of lncRNAs was altered in the jejuna of mice post‐irradiation. Moreover, it provides a resource for the study of lncRNAs in the radiation‐induced intestinal injury.

Evaluation on the genetic instability detecting methods for rapid diagnose of Fanconi anemia used in the undeveloped areas of China

Fanconi anemia (FA), as one of the congenital bone marrow failure syndromes, is characterized by severe bone marrow hypocellularity and pancytopenia which is similar with acquired aplastic anemia (AAA). However, patients with FA or AAA need an accurate diagnose, as the two syndromes differ significantly in both treatment and prognosis. FA results from gene mutations of the FA pathway genes specifically required for DNA repair, and the mutation of these genes contributes to the genome instability of FA cells. Based on this feature, chromosome aberration (CA) has been used as a “golden standard” to the auxiliary diagnosis of FA from AAA. However, CA diagnose calls for more technical requirements and a long time for the subsequent statistical analysis.

WITHDRAWN: Cytogenetics alteration in adult men involved in the recycling of electronic wastes

Abstract In this data article, 146 villagers (exposed group) were randomly selected from the workers who involved in the e-wastes recycling directly as a daily job in Tianjin. Control group, including 121 villagers, came from another town without e-waste disposal sites. Chromosomal aberrations (CA) and cytokinesis blocking micronucleus (CBMN) were performed to detect the cytogenetic effect for each subject. DNA damage was detected using comet assay; the DNA percentage in the comet tail (TDNA%), tail moment (TM), and Olive tail moment (OTM) were recorded to describe DNA damage to lymphocytes and spermatozoa. Routine semen analysis, spermatozoa motility and morphology were analyzed. The RT 2 Profiler PCR array was used to measure levels of expression of 84 genes related to quality of DNA. It showed significant relationships between CA, CBMN, DNA damage and exposure time in exposure subjects. The alteration of sperm motility rate, abnormality rate and total sperm counts had association with exposure time and age.

Regulation of Apoptosis and Radiation Sensitization in Lung Cancer Cells via the Sirt1/NF-κB/Smac Pathway

Background/Aims: SirT1, a conserved NAD+-dependent deacetylase, has been implicated in modulating cell survival and stress responses, and it appears to play an important role in tumorigenesis and cancer resistance to chemoradiotherapy. The mechanism of SirT1 in cancer chemoradiotherapy remains to be further elucidated, which could provide potential targets for cancer therapy. Methods: We performed colony formation, immunofluorescence microscopy, flow cytometry, RNA interference, and western blotting assays to determine whether SirT1 regulates radiation sensitization and which mechanisms and/or pathways it takes in lung cancer cell lines A549 and H460. Results: Initially, the expression of SirT1 was found to be negatively correlated with radiosensitivity in lung cancer cell lines A549 and H460. RNA interference with siSirT1 against SirT1 specifically reduced SirT1 expression and induced radiosensitivity both in A549 and H460 cell lines. In contrast, the radiosensitivity was significantly reduced once SirT1 was activated by resveratrol. Immunofluorescence assay and apoptosis analysis indicated that the effect of SirT1 on the radiosensitivity observed in the A549 and H460 cell lines was mainly achieved by regulating DNA damage repair and apoptosis processes. Furthermore, the expression of SirT1 negatively modulated the expression of apoptosis-related protein NF-κB and its downstream regulator of Smac. Conclusion: Our results indicate that SirT1 regulates apoptosis and radiation sensitization in lung cancer cell lines A549 and H460 via the SirT1/NF-κB/Smac pathway.

MSCs inhibit tumor progression and enhance radiosensitivity of breast cancer cells by down-regulating Stat3 signaling pathway

The acquisition of radioresistance by breast cancer cells during radiotherapy may lead to cancer recurrence and poor survival. Signal transducer and activator of transcription 3 (Stat3) is activated in breast cancer cells and, therefore, may be an effective target for overcoming therapeutic resistance. Mesenchymal stem cells (MSCs) have been investigated for use in cancer treatment. Here, we investigated the potential of MSC conditioned medium (MSC-CM) in sensitizing breast cancer to radiotherapy. It was found that MSC-CM could inhibit the level of activated Stat3, suppress cancer growth, and exhibit synergetic effects with radiation treatment in vitro and in vivo. Furthermore, MSC-CM reduced the ALDH-positive cancer stem cells (CSCs) population, modulated several potential stem cell markers, and decreased tumor migration, as well as metastasis. These results demonstrate that MSC-CM suppresses breast cancer cells growth and sensitizes cancer cells to radiotherapy through inhibition of the Stat3 signaling pathway, thus, providing a novel strategy for breast cancer therapy by overcoming radioresistance.

TAZ inhibition promotes IL-2-induced apoptosis of hepatocellular carcinoma cells by activating the JNK/F-actin/mitochondrial fission pathway

BackgroundCytokine-based cancer therapies have attracted a great deal of attention in recent years. Unfortunately, resistance to treatment limits the efficacy of these therapeutics. Therefore, the aim of our study was to explore the mechanism of IL-2-based therapy for hepatocellular carcinoma in an attempt to increase the efficiency of this treatment option.MethodsHepG2 cells were treated with IL-2. Then, siRNA against TZA was used to transfected into HepG2 cells. Cellular apoptosis was measured via MTT assay, TUNEL assay and caspase-3 activity. Cellular proliferation was evaluated via EdU assay and western blotting. Cellular migration was detected via Transwell assay. Mitochondrial function was monitored by mitochondrial potential analysis, ROS staining, immunofluorescence and western blotting. Pathway blocker and activator were used to establish the role of JNK/F-actin/mitochondrial fission signaling pathway in HepG2 cells stress response.ResultsOur study found that IL-2 treatment significantly reduced the viability, mobility and proliferation of HepG2 cells in vitro. We also demonstrated that IL-2 treatment was accompanied by an increase in the expression of transcriptional co-activator with PDZ-binding motif (TAZ). Interestingly, genetic ablation of TAZ in the presence of IL-2 further promoted apoptosis, inhibited mobility, and arrested proliferation in HepG2 cells. At the molecular level, IL-2 administration activated excessive mitochondrial fission via the JNK/F-actin pathway; these effects were further enhanced by TAZ deletion. Mechanistically, TAZ knockdown further increased the expression of mitochondrial fission-related proteins such as Drp1, Mff and Fis. The augmented mitochondrial fission stimulated ROS overproduction, mediated redox imbalance, interrupted mitochondrial energy generation, reduced mitochondrial membrane potential, promoted leakage of the pro-apoptotic molecule cyt-c into the nucleus, and initiated caspase-9-related mitochondrial death. Further, we demonstrated that the anti-proliferative and anti-metastatic effects of IL-2 in HepG2 cells were enhanced by TAZ deletion, suggesting that IL-2 sensitizes HepG2 cells to IL-2-based cytokine therapy. However, JNK/F-actin pathway blockade could abrogate the inhibitory effects of TAZ deletion on HepG2 migration, proliferation and survival.ConclusionsTaken together, our data indicate that the anti-tumor effects of IL-2-based therapies may be enhanced by TAZ deletion in a JNK/F-actin pathway-dependent manner. This finding provides a novel combinatorial therapeutic approach for treating hepatocellular carcinoma that might significantly increase the efficacy of cytokine-based therapies in a clinical setting.

Sirt3-mediated mitochondrial fission regulates the colorectal cancer stress response by modulating the Akt/PTEN signalling pathway

Sirtuin-3 (Sirt3), a sub-family member of the nicotinamide adenine dinucleotide-dependent histone deacetylases, has been reported to be involved in mitochondrial oxidative stress regulation, mitochondrial calcium management, mitophagy activation, and mitochondrial energy metabolism. The aim of our study was to explore the functional role of Sirt3 in colorectal cancer stress, focusing particularly on its effects on mitochondrial fission. Our study demonstrated that Sirt3 was highly upregulated in colorectal cancer cells compared to normal rectal mucosa cells. However, the genetic ablation of Sirt3 reduced colorectal cancer cell viability, mobility and proliferation. At the molecular level, we found that Sirt3 knockdown suppressed the expression of adhesive factors and cyclins. Furthermore, Sirt3 deletion was also associated with mitochondrial membrane potential reduction, ROS overproduction, mPTP opening, mitochondrial pro-apoptotic upregulation, and caspase-9-related death programme activation. Furthermore, we determined that Sirt3 regulated the colorectal cancer stress response by modulating mitochondrial fission. The loss of Sirt3 triggered fatal mitochondrial fission by suppressing the Akt/PTEN pathway. Re-activation of the Akt/PTEN pathway combatted mitochondrial fission and promoted colorectal cancer mobility, survival, and growth. Altogether, these findings provide an additional rationale for the function of Sirt3 in supporting the growth and survival of colorectal cancer.