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Abstract: To study the molecular and cellular mechanisms of radiation-induced lung injury (RILI) in a non-human primate model, Rhesus macaques were irradiated with lethal doses of radiation to the whole thorax. A subset of the irradiated animals was treated with AEOL 10150, a potent catalytic scavenger of reactive oxygen and nitrogen species. Lung tissues were collected at necropsy for molecular and immunohistochemical (IHC) studies. Microarray expression profiling in the irradiated lung tissues identified differentially expressed genes (DEGs) and pathways important in innate immunity. The elevated expression of cytokines (CCL2, CCL11, IL-8), complement factors (CFB, C3), apoptosis-related molecules (p53, PTEN, Bax, p21, MDM2, c-Caspase 3), and adhesion molecules (fibronectin, integrin β6, ICAM-1) were further studied using real-time PCR, Western blot, or IHC. Oxidative stress and pulmonary inflammatory cell infiltration were increased in the irradiated lungs. Treatment with AEOL 10150 significantly decreased oxidative stress and monocyte/macrophage infiltration. Cytokine/chemokine-induced excessive innate immune response after thoracic irradiation plays an important role in RILI. To our knowledge, this is the first study to highlight the role of cytokine/chemokine-induced innate immune responses in radiation-induced pulmonary toxicity in a NHP model., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 Health Physics Society.)

Purpose: The current study aimed to investigate the role of long intergenic noncoding 01433 (LINC01433) in the proliferation, migration and invasion of nasopharyngeal carcinoma (NPC)., Methods: Real-time quantitative PCR (RT-qPCR) was performed to determine the expressions of LINC01433 and miR-506-3p in NPC samples and cell lines. The effects of LINC01433 on cell proliferation, migration and invasion were measured by CCK-8, wound healing assay and Transwell, respectively. In addition, Pearson correlation analysis, starBase, RNA immunoprecipitation, luciferase assay, Western blot and functional experiments were conducted to detect and confirm the relationship between LINC01433 and miR-506-3p., Results: LINC01433 level was noticeably elevated in NPC tissues and cell lines. As the expression of LINC01433 in 5-8F cells was the highest in NPC cell lines and the expression of LINC01433 in SUNE1 cells was the lowest, 5-8F and SUNE1 cells were therefore selected as the target cells for following experiments. Furthermore, miR-506-3p was predicted as the target of LINC01433, and the two were negatively correlated with each other. Interestingly, overexpression of LINC01433 promoted proliferation, migration and invasion of NPC cells, while miR-506-3p reversed such effects of LINC01433. Moreover, LINC01433 silencing had the opposite effects to LINC01433 overexpression. Furthermore, miR-506-3p overexpression inhibited the expressions of MMP2, N-cadherin, p-PI3K and p-Akt, and promoted the expressions of E-cadherin and TIMP-2, and partially reversed the role of LINC01433 in promoting cancer development., Conclusion: The current findings reveal that LINC01433 regulates NPC cell biological progress through miR-506-3p., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.)

Chartered by the U.S. Congress in 1961, the Armed Forces Radiobiology Research Institute (AFRRI) is a Joint Department of Defense (DoD) entity with the mission of carrying out the Medical Radiological Defense Research Program in support of our military forces around the globe. In the last 60 years, the investigators at AFRRI have conducted exploratory and developmental research with broad application to the field of radiation sciences. As the only DoD facility dedicated to radiation research, AFRRI's Medical Radiobiology Advisory Team provides deployable medical and radiobiological subject matter expertise, advising commanders in the response to a U.S. nuclear weapon incident and other nuclear or radiological material incidents. AFRRI received the DoD Joint Meritorious Unit Award on February 17, 2004, for its exceptionally meritorious achievements from September 11, 2001 to June 20, 2003, in response to acts of terrorism and nuclear/radiological threats at home and abroad. In August 2009, the American Nuclear Society designated the institute a nuclear historic landmark as the U.S.'s primary source of medical nuclear and radiological research, preparedness and training. Since then, research has continued, and core areas of study include prevention, assessment and treatment of radiological injuries that may occur from exposure to a wide range of doses (low to high). AFRRI collaborates with other government entities, academic institutions, civilian laboratories and other countries to research the biological effects of ionizing radiation. Notable early research contributions were the establishment of dose limits for major acute radiation syndromes in primates, applicable to human exposures, followed by the subsequent evolution of radiobiology concepts, particularly the importance of immune collapse and combined injury. In this century, the program has been essential in the development and validation of prophylactic and therapeutic drugs, such as Amifostine, Neupogen®, Neulasta®, Nplate® and Leukine®, all of which are used to prevent and treat radiation injuries. Moreover, AFRRI has helped develop rapid, high-precision, biodosimetry tools ranging from novel assays to software decision support. New drug candidates and biological dose assessment technologies are currently being developed. Such efforts are supported by unique and unmatched radiation sources and generators that allow for comprehensive analyses across the various types and qualities of radiation. These include but are not limited to both 60Co facilities, a TRIGA® reactor providing variable mixed neutron and γ-ray fields, a clinical linear accelerator, and a small animal radiation research platform with low-energy photons. There are five major research areas at AFRRI that encompass the prevention, assessment and treatment of injuries resulting from the effects of ionizing radiation: 1. biodosimetry; 2. low-level and low-dose-rate radiation; 3. internal contamination and metal toxicity; 4. radiation combined injury; and 5. radiation medical countermeasures. These research areas are bolstered by an educational component to broadcast and increase awareness of the medical effects of ionizing radiation, in the mass-casualty scenario after a nuclear detonation or radiological accidents. This work provides a description of the military medical operations as well as the radiation facilities and capabilities present at AFRRI, followed by a review and discussion of each of the research areas., (©2021 by Radiation Research Society. All rights of reproduction in any form reserved.)

Radiation combined injury (RCI, radiation exposure coupled with other forms of injury, such as burn, wound, hemorrhage, blast, trauma and/or sepsis) comprises approximately 65% of injuries from a nuclear explosion, and greatly increases the risk of morbidity and mortality when compared to that of radiation injury alone. To date, no U.S. Food and Drug Administration (FDA)-approved countermeasures are available for RCI. Currently, three leukocyte growth factors (Neupogen®, Neulasta® and Leukine®) have been approved by the FDA for mitigating the hematopoietic acute radiation syndrome. However these granulocyte-colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) products have failed to increase 30-day survival of mice after RCI, suggesting a more complicated biological mechanism is in play for RCI than for radiation injury. In the current study, the mitigative efficacy of combination therapy using pegylated (PEG)-G-CSF (Neulasta) and -citrulline was evaluated in an RCI mouse model. L-citrulline is a neutral alpha-amino acid shown to improve vascular endothelial function in cardiovascular diseases. Three doses of PEG-G-CSF at 1 mg/kg, subcutaneously administered on days 1, 8 and 15 postirradiation, were supplemented with oral -citrulline (1 g/kg), once daily from day 1 to day 21 postirradiation. The combination treatment significantly improved the 30-day survival of mice after RCI from 15% (vehicle-treated) to 42%, and extended the median survival time by 4 days, as compared to vehicle controls. In addition, the combination therapy significantly increased body weight and bone marrow stem and progenitor cell clonogenicity in RCI mice, and accelerated recovery from RCI-induced intestinal injury, compared to animals treated with vehicle. Treatment with -citrulline alone also accelerated skin wound healing after RCI. In conclusion, these data indicate that the PEG-G-CSF and -citrulline combination therapy is a potentially effective countermeasure for mitigating RCI, likely by enhancing survival of the hematopoietic stem/progenitor cells and accelerating recovery from the RCI-induced intestinal injury and skin wounds., (©2021 by Radiation Research Society. All rights of reproduction in any form reserved.)

Background: Among head and neck squamous cell carcinomas (HNSCCs), hypopharyngeal squamous cell carcinoma (HPSCC) has the worst prognosis. Iron metabolism, which plays a crucial role in tumor progression, is mainly regulated by alterations to genes and post-transcriptional processes. The recent discovery of the N6-methyladenosine (m 6 A) modification has expanded the realm of previously undiscovered post-transcriptional gene regulation mechanisms in eukaryotes. Many studies have demonstrated that m 6 A methylation represents a distinct layer of epigenetic deregulation in carcinogenesis and tumor proliferation. However, the status of m 6 A modification and iron metabolism in HPSCC remains unknown. Methods: Bioinformatics analysis, sample analysis, and transcriptome sequencing were performed to evaluate the correlation between m 6 A modification and iron metabolism. Iron metabolic and cell biological analyses were conducted to evaluate the effect of the m 6 A reader YTHDF1 on HPSCC proliferation and iron metabolism. Transcriptome-wide m 6 A-seq and RIP-seq data were mapped to explore the molecular mechanism of YTHDF1 function in HPSCC. Results: YTHDF1 was found to be closely associated with ferritin levels and intratumoral iron concentrations in HPSCC patients at Sir Run Run Shaw Hospital. YTHDF1 induced-HPSCC tumorigenesis depends on iron metabolism in vivo in vitro . Mechanistically, YTHDF1 methyltransferase domain interacts with the 3'UTR and 5'UTR of TRFC mRNA, then further positively regulates translation of m 6 A-modified TFRC mRNA. Gain-of-function and loss-of-function analyses validated the finding showing that TFRC is a crucial target gene for YTHDF1-mediated increases in iron metabolism. Conclusion: YTHDF1 enhanced TFRC expression in HPSCC through an m 6 A-dependent mechanism. From a therapeutic perspective, targeting YTHDF1 and TFRC-mediated iron metabolism may be a promising strategy for HPSCC., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Background: Compared to radiation injury alone (RI), radiation injury combined wound (CI) further enhances acute radiation syndrome and subsequently mortality. We previously reported that therapy with Ghrelin, the 28-amino-acid-peptide secreted from the stomach, significantly increased 30-day survival and mitigated hematopoietic death by enhancing and sustaining granulocyte-colony stimulating factor (G-CSF) and keratinocyte chemoattractant (KC) in the blood and bone marrow; increasing circulating white blood cell depletion; inhibiting splenocytopenia; and accelerating skin-wound healing on day 30 after CI. Herein, we aimed to study the efficacy of Ghrelin on intestinal injury at early time points after CI., Methods: B6D2F1/J female mice were exposed to 60 Co-γ-photon radiation (9.5 Gy, 0.4 Gy/min, bilateral), followed by 15% total-body-surface-area skin wounds. Several endpoints were measured: at 4-5 h and on days 1, 3, 7, and 15., Results: Ghrelin therapy mitigated CI-induced increases in IL-1β, IL-6, IL-17A, IL-18, KC, and TNF-α in serum but sustained G-CSF, KC and MIP-1α increases in ileum. Histological analysis of ileum on day 15 showed that Ghrelin treatment mitigated ileum injury by increasing villus height, crypt depth and counts, as well as decreasing villus width and mucosal injury score. Ghrelin therapy increased AKT activation and ERK activation; suppressed JNK activation and caspase-3 activation in ileum; and reduced NF-κB, iNOS, BAX and Bcl-2 in ileum. This therapy recovered the tight junction protein and mitigated bacterial translocation and lipopolysaccharides levels. The results suggest that the capacity of Ghrelin therapy to reduce CI-induced ileum injury is mediated by a balanced NF-κB-AKT-MAPK network that leads to homeostasis of pro-inflammatory and anti-inflammatory cytokines., Conclusions: Our novel results are the first to suggest that Ghrelin therapy effectively decreases intestinal injury after CI., Competing Interests: Competing interestsThe authors declare that they have no conflict of interests., (© The Author(s) 2020.)

Cryptococcus neoformans is a basidiomycete fungus that is highly resistant to ionizing radiation and has been identified in highly radioactive environments. Transcription factors (TFs) are master regulators of gene expression by binding to specific DNA sequences within promoters of target genes. A library of 322 signature-tagged gene deletion strains for 155 C. neoformans TF genes has been established. Previous phenome-based functional analysis of the C. neoformans TF mutant library identified key TFs important for various phenotypes, such as growth, differentiation, virulence-factor production, and stress responses. Here, utilizing the established TF mutant library, we identified 5 TFs that are important for radiation sensitivity, including SRE1, BZP2, GAT5, GAT6, and HCM1. Interestingly, BZP2, GAT5 and GAT6 all belong to the GATA-type transcription factors. These factors regulate transcription of nitrogen catabolite repression (NCR) sensitive genes when preferred nitrogen sources are absent or limiting. In addition to radiation, we found that specific GATA factors are important for other stressors such as rapamycin, fluconazole, and hydroxyurea treatment. Using real-time PCR method, we studied the expression of GATA down-stream genes after radiation exposure and identified that AAP4, AAP5 and URO1 were differentially expressed in the GAT5 and GAT6 mutants compared to the wild type cells. In summary, our data suggest that GATA TFs are important for radiation sensitivity in C. neoformans by regulating specific downstream AAP genes.

Head and neck squamous cell carcinoma (HNSCC) is highly variable by tumor site, histologic type, molecular characteristics, and clinical outcome. During recent years, emerging targeted therapies have been focused on driver genes. HNSCC involves several genetic alterations, such as co-occurrence, multiple feedback loops, and cross-talk communications. These different kinds of genetic alterations interact with each other and mediate targeted therapy response. In the current review, it is emphasized that future treatment strategy in HNSCC will not solely be based on "synthetic lethality" approaches directed against overactivated genes. More importantly, biologic, genetic, and epigenetic alterations of HNSCC will be taken into consideration to guide the therapy. The emerging genetic alterations in HNSCC and its effect on targeted therapy response are discussed in detail. Hopefully, novel combination regimens for the treatment of HNSCC can be developed., Competing Interests: Disclosure The authors report no conflicts of interests in this work.

In this study, we investigated the effects of low-to-moderate doses of radiation in mice, given our limited understanding of the health risks associated with these exposures. Here, we demonstrate the different responses of the CD2F1 mouse hematopoietic system to low-to-moderate (0.5, 1, 3 or 5 Gy) doses of gamma radiation. After 3 and 5 Gy of 60 Co total-body irradiation (TBI), mouse blood cell counts were decreased and maintained below baseline up to 28-42 days. In contrast, after 0.5 Gy TBI, lymphocyte and monocyte counts increased, and peaked from day 3 to day 14. Radiation doses at 0.5 and 1 Gy did not cause cell death or T-cell subpopulation changes in spleen and thymus, whereas the clonogenicity of mouse bone marrow (BM) progenitor cells was significantly suppressed on the first day after 0.5-5 Gy TBI, and these low levels were maintained up to 42 days. Although a transient recovery in total colony forming units (CFUs) was shown in mouse BM at days 14 and 21 after 0.5 Gy TBI, the early-stage multipotential progenitor colonies (CFU-GEMM) remained at a significantly low level compared to those of the sham-irradiated (0 Gy) controls. Consistently, the level of stem cell factor (SCF) in BM cells was decreased after low-to-moderate TBI. Serum from individual mice was collected after irradiation and 23 cytokines/chemokines were measured; massive releases of cytokines and chemokines were observed at day 3 postirradiation in a dose-dependent manner. When human hematopoietic CD34 + cells were cultured with the serum collected from mice irradiated at different doses, a significant decrease of CFU-GEMM colonies in the CD34 + cells was observed. Our data suggest that low-to-moderate doses of radiation induced cellular responses that are cell type-dependent. The early stage multipotential progenitor cells in mouse BM were the most sensitive cells even to low-dose irradiation compared to spleen and thymic cells, and 0.5 Gy TBI induced hematopoietic cell injury from day 1 to the end of our experiment, day 42 postirradiation. Radiation-induced decrease of SCF in mouse BM and increase in circulating pro-inflammatory factors may be responsible for the enhanced sensitivity of hematopoietic progenitor cells to radiation.

Traditional cancer therapy is mainly targeting on enhancing cell apoptosis, however, it is well established that many cancer cells are chemo-resistant and defective in apoptosis induction. Therefore, it may have important therapeutic implications to exploit some novel natural compounds based on non-apoptotic programmed cell death. Currently, accumulating evidence shows that the compounds from nature source can induce non-apoptotic programmed cell death in cancer cells, and therefore these natural compounds have gained a great promise for the future anticancer therapeutics. In this review, we will concentrate our efforts on the latest developments regarding major forms of non-apoptotic programmed cell death--autophagic cell death, necroptosis, ferroptosis, pyroptosis, glutamoptosis and exosome-associated cell death. Our increased understanding of the role of natural compounds in regulating non-apoptotic programmed cell death will hopefully provide prospective strategies for cancer therapy., (Copyright © 2018 Elsevier B.V. All rights reserved.)

We have reported that circulating IL-18 can be used as a radiation biomarker in mice, minipigs and nonhuman primates (NHPs, Macaca mulatta). Here, we report the levels of IL-18 in individual NHP's urine before and at 6 h-7 days after 5.0, 6.5 and 8.5 Gy 60 Co total-body irradiation (TBI) using enzyme linked immunosorbent assay (ELISA). Six animals (3.5-5.5 kg, 3-4 years old) per radiation dose were investigated. Correlation values between urine IL-18 and blood cell counts and serum chemistry parameters including lactate dehydrogenase (LDH), lipase, and serum total protein (TP), as well as between urine IL-18 and 60-day survival, were analyzed. Our data, to the best of our knowledge, for the first time, demonstrate that concentrations of urine IL-18 from irradiated NHPs were increased in a radiation dose-dependent manner compared to pre-TBI levels in samples from these animal (N = 18, 11.02 ± 1.3 pg/ml). A 5.0 Gy low dose of radiation (∼LD 10/60 ) did not increase urine IL-18 levels. In contrast, high-dose TBI significantly increased urine IL-18 at day 1 to day 5 in a bell-shaped time course, reaching a peak of 5- to 10-fold of control levels on day 3 after 6.5 Gy (∼LD 50/60 ) and 8.5 Gy (∼LD 90/60 ), respectively. Statistical analysis using receiver operator characteristic (ROC) and MultiROC analysis indicated that white blood cell and platelet counts, serum LDH, lipase and TP, when combined with urine IL-18, provide discriminatory predictors of total-body radiation injury with a very high ROC area of 0.98. Urine IL-18 measurement, as an early prognostic indicator of survival, may facilitate rapid detection of lethal doses of radiation, based on the currently available data set.

We previously reported that microRNA-30 (miR-30) expression was initiated by radiation-induced proinflammatory factor IL-1β and NFkB activation in mouse and human hematopoietic cells. However, the downstream effectors of miR-30 and its specific role in radiation-induced cell death are not well understood. In the present study, we evaluated effects of radiation on miR-30 expression and activation of intrinsic apoptotic pathway Bcl-2 family factors in in vivo mouse and in vitro human hematopoietic cells. CD2F1 mice and human CD34+ cells were exposed to different doses of gamma-radiation. In addition to survival studies, mouse blood, bone marrow (BM) and spleen cells and human CD34+ cells were collected at 4 h, and 1, 3 and 4 days after irradiation to determine apoptotic and stress response signals. Our results showed that mouse serum miR-30, DNA damage marker γ-H2AX in BM, and Bim, Bax and Bak expression, cytochrome c release, and caspase-3 and -7 activation in BM and/or spleen cells were upregulated in a radiation dose-dependent manner. Antiapoptotic factor Mcl-1 was significantly downregulated, whereas Bcl-2 was less changed or unaltered in the irradiated mouse cells and human CD34+ cells. Furthermore, a putative miR-30 binding site was found in the 3' UTR of Mcl-1 mRNA. miR-30 directly inhibits the expression of Mcl-1 through binding to its target sequence, which was demonstrated by a luciferase reporter assay, and the finding that Mcl-1 was uninhibited by irradiation in miR-30 knockdown CD34+ cells. Bcl-2 expression was not affected by miR-30. Our data suggest miR-30 plays a key role in radiation-induced apoptosis through directly targeting Mcl-1in hematopoietic cells.

We have previously reported that circulating interleukin-18 (IL-18) can be used as a radiation biomarker in mice, minipigs and nonhuman primates. In this study, we further determined the serum levels of IL-18 binding protein (IL-18BP), a natural endogenous antagonist of IL-18, in CD2F1 mice 1-13 days after total-body gamma irradiation (TBI) with different doses (5-10 Gy). We compared the changes in blood lymphocyte, neutrophil and platelet counts as well as the activation of the proapoptotic executioner caspase-3 and caspase-7, and the expression of the inflammatory factor cyclooxygenase 2 (COX-2) in spleen cells, with the changes of IL-18BP and IL-18 in mouse serum. We also evaluated the significance, sensitivity and specificity of alterations in radiation-induced IL-18BP. IL-18 increased from day 1-13 after TBI in a dose-dependent manner that was paralleled with an increase in IL-18 receptor alpha (IL-18Rα) in irradiated mouse spleen cells. IL-18BP rapidly increased (25-63 fold) in mouse serum on day 1 after different doses of TBI. However, it returned to baseline within 3 days after 5-7 Gy doses and within 7 days after 8 Gy dose, and was unaltered thereafter. In contrast, high doses of radiation (9 and 10 Gy) significantly sustained a higher level of IL-18BP in mouse serum and later induced a second phase of increase in IL-18BP on day 9-13 after irradiation, which coincided with the onset of animal mortality. Consistent with this observation, highly activated caspase-3 and -7 in 8-10 Gy irradiated mouse spleen cells exhibited reduced or no activity 24 h after 5 Gy, although radiation induced an inflammatory response, as shown by COX-2 expression in all irradiated cells. Our data suggest that the radiation-induced differential elevation of IL-18 and IL-18BP in animal serum is a dynamic and discriminative indicator of the severity of injury after exposure to ionizing radiation. These findings support the inclusion of the dual biomarkers IL-18BP and IL-18 in the development of a multifactorial strategy for radiation dose and injury assessment.

Objective: To explore the feasible monitoring techniques for the buried free flap., Method: Buried free flaps in reconstruction were monitored using combined monitoring techniques in five cases of advanced hypopharyngeal cancer The monitoring effects were analyzed retrospectively., Result: The operations were carried out successfully and all the five patients got primary healing of incision without vascular crisis. Four patients need combined monitoring techniques to confirm the microcirculatory results of the buried free flap., Conclusion: Application of Doppler combined with flap island was feasible on monitoring the blood supply of post-operative buried free flap, it is a good monitoring technique.

We recently demonstrated that natural delta-tocotrienol (DT3) significantly enhanced survival in total-body irradiated (TBI) mice, and protected mouse bone marrow cells from radiation-induced damage through Erk activation-associated mTOR survival pathways. Here, we further evaluated the effects and mechanisms of DT3 on survival of radiation-induced mouse acute gastrointestinal syndrome. DT3 (75-100 mg/kg) or vehicle was administered as a single subcutaneous injection to CD2F1 mice 24 h before 10-12 Gy (60)Co total-body irradiation at a dose rate of 0.6 Gy/min and survival was monitored. In a separate group of mice, jejunum sections were stained with hematoxylin and eosin and the surviving crypts in irradiated mice were counted. Apoptosis in intestinal epithelial cells was measured by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) staining and bacterial translocation from gut to heart, spleen and liver in irradiated mice were evaluated. DT3 (75 mg/kg) significantly enhanced survival in mice that received 10, 10.5, 11 or 12 Gy TBI. Administration of DT3 protected intestinal tissue, decreased apoptotic cells in jejunum and inhibited gut bacterial translocation in irradiated mice. Furthermore, DT3 significantly inhibited radiation-induced production of pro-inflammatory factors interleukin-1β and -6 and suppressed expression of protein tyrosine kinase 6 (PTK6), a stress-induced kinase that promotes apoptosis in mouse intestinal cells. Our data demonstrate that administration of DT3 protected mice from radiation-induced gastrointestinal system damage.

Previous studies demonstrated that genistein protects mice from radiation-induced bone marrow failure. To overcome genistein's extremely low water solubility, a nanoparticle suspension of genistein has been formulated for more rapid dissolution. In the current study, we evaluated the radioprotective effects of a nanoparticle formulation of genistein on survival and hematopoietic recovery in mice exposed to total-body gamma irradiation. A single intramuscular injection of a saline-based genistein nanosuspension (150 mg/kg) administered to CD2F1 mice 24 h before 9.25 Gy (60)Co radiation exposure resulted in a 30-day survival rate of 95% compared to 25% in vehicle-treated animals. In mice irradiated at 7 Gy, the genistein nanosuspension increased mouse bone marrow cellularity from approximately 2.9% (vehicle treated) to 28.3% on day 7 postirradiation. Flow cytometry analysis demonstrated decreased radiation-induced hematopoietic stem and progenitor cell (HSPC, Lineage(-)/cKit(+)) death from 77.0% (vehicle) to 43.9% (genistein nanosuspension) with a significant recovery of clonogenicity 7 days after irradiation. The genistein nanosuspension also attenuated the radiation-induced elevation of proinflammatory factors interleukin 1 beta (IL-1β), IL-6 and cyclooxygenase-2 (COX-2) in mouse bone marrow and spleen, which may contribute to protecting HSPCs.

As members of adhesion molecule families, CD44 transmembrane glycoproteins have been originally thought to be essential for the formation of multicellular organisms and soon recognised to be able to initiate metastatic spread of tumour cells. To investigate the association between CD44 polymorphisms and nasopharyngeal carcinoma (NPC), we carried out a two-stage case-control study in 906 patients and 943 healthy controls in Eastern populations. Five single nucleotide polymorphisms of CD44 (rs10836347C>T, rs13347C>T, rs1425802A>G, rs11821102G>A and rs713330T>C) with proper frequency were selected from the HapMap database and genotyped with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Compared with the most common rs13347CC genotype, CT+TT genotypes significantly increased individuals' susceptibility to NPC (odds ratio = 2.58, 95% confidence interval = 2.13-3.13). Furthermore, our transient transfection focusing on reporter gene expression modulated by CD44 3'UTR demonstrated that the presence of an rs13347T allele led to greater transcriptional activity than the C allele. Similarly, more CD44 expression was shown in rs13347T carriers than C carriers in our western blotting results. All these findings suggest that CD44 rs13347C>T polymorphism may affect NPC development by improving CD44 expression.

Objective: Transforming growth factor β1 (TGFβ1) promotes tumor growth and metastasis in the later stage of cancer development. In this study, we explored whether TGFβ1 polymorphisms were associated with increased risk of nasopharyngeal carcinoma (NPC) in a Chinese population., Design: Case-control study., Setting: Hospitals of the Department of Otorhinolaryngology-Head and Neck Surgery., Subjects and Methods: Two single nucleotide polymorphisms of TGFβ1 gene promoter -509C/T (rs1800469) and 869T/C (Leu 10 Pro, rs1800470) at exon 1 were analyzed in 522 NPC patients and 712 age- and sex-matched controls in a Chinese population, using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Functional relevance of the polymorphism was determined by biochemical assays., Results: The -509T allele carriers were associated with a significantly reduced risk of NPC as compared with the noncarriers (odds ratio [OR], 0.67; 95% confidence interval [CI], 0.53-0.89 and OR, 0.50; 95% CI, 0.31-0.67, respectively). Moreover, -509C-containing TGFβ1 promoter drove an ~1.7-fold increase in reporter expression, compared with the -509T-containing counterpart in both CNE-1 and CNE-2 cell lines. The TGFβ1 -509 CC genotype carriers had a higher TGFβ1 mRNA level than the TGFβ1 -509TT genotype carriers did (P < .01). However, no significant association was observed between the 869T/C polymorphism and risk of NPC., Conclusion: These findings indicate that the -509C/T polymorphism in TGFβ1 may play a vital role in mediating individual susceptibility to NPC.

Background: Exposure to γ-radiation causes rapid hematopoietic cell apoptosis and bone marrow suppression. However, there are no approved radiation countermeasures for the acute radiation syndrome. In this study, we demonstrated that natural δ-tocotrienol, one of the isomers of vitamin E, significantly enhanced survival in total body lethally irradiated mice. We explored the effects and mechanisms of δ-tocotrienol on hematopoietic progenitor cell survival after γ-irradiation in both in vivo and in vitro experiments., Design and Methods: CD2F1 mice and human hematopoietic progenitor CD34(+) cells were treated with δ-tocotrienol or vehicle control 24 h before or 6 h after γ-irradiation. Effects of δ-tocotrienol on hematopoietic progenitor cell survival and regeneration were evaluated by clonogenicity studies, flow cytometry, and bone marrow histochemical staining. δ-tocotrienol and γ-irradiation-induced signal regulatory activities were assessed by immunofluorescence staining, immunoblotting and short-interfering RNA assay., Results: δ-tocotrienol displayed significant radioprotective effects. A single injection of δ-tocotrienol protected 100% of CD2F1 mice from total body irradiation-induced death as measured by 30-day post-irradiation survival. δ-tocotrienol increased cell survival, and regeneration of hematopoietic microfoci and lineage(-)/Sca-1(+)/ckit(+) stem and progenitor cells in irradiated mouse bone marrow, and protected human CD34(+) cells from radiation-induced damage. δ-tocotrienol activated extracellular signal-related kinase 1/2 phosphorylation and significantly inhibited formation of DNA-damage marker γ-H2AX foci. In addition, δ-tocotrienol up-regulated mammalian target of rapamycin and phosphorylation of its downstream effector 4EBP-1. These alterations were associated with activation of mRNA translation regulator eIF4E and ribosomal protein S6, which is responsible for cell survival and growth. Inhibition of extracellular signal-related kinase 1/2 expression by short interfering RNA abrogated δ-tocotrienol-induced mammalian target of rapamycin phosphorylation and clonogenicity, and increased γ-H2AX foci formation in irradiated CD34(+) cells., Conclusions: Our data indicate that δ-tocotrienol protects mouse bone marrow and human CD34(+) cells from radiation-induced damage through extracellular signal-related kinase activation-associated mammalian target of rapamycin survival pathways.

Background: The tumor suppressor TP53 and its negative regulator MDM2 play crucial roles in carcinogenesis. Previous case-control studies also revealed TP53 72Arg>Pro and MDM2 309T>G polymorphisms contribute to the risk of common cancers. However, the relationship between these two functional polymorphisms and nasopharyngeal carcinoma (NPC) susceptibility has not been explored., Methods: In this study, we performed a case-control study between 522 NPC patients and 722 healthy controls in a Chinese population by using PCR-RFLP., Results: We found an increased NPC risk associated with the MDM2 GG (odds ratio [OR] = 2.83, 95% confidence interval [CI] = 2.08-3.96) and TG (OR = 1.49, 95% CI = 1.16-2.06) genotypes. An increased risk was also associated with the TP53 Pro/Pro genotype (OR = 2.22, 95% CI = 1.58-3.10) compared to the Arg/Arg genotype. The gene-gene interaction of MDM2 and TP53 polymorphisms increased adult NPC risk in a more than multiplicative manner (OR for the presence of both MDM2 GG and TP53 Pro/Pro genotypes = 7.75, 95% CI = 3.53-17.58)., Conclusion: The findings suggest that polymorphisms of MDM2 and TP53 genes may be genetic modifier for developing NPC.

Objective: To investigate the role of nasal mucosa fibrosis on radiation induced nasal mucosa injury., Methods: Seventy two male rats were randomly divided into two groups, control group and irradiation injured group (radiation dose were 40 Gy); the rats were killed 1 week, 2 weeks, 4 weeks, 8 weeks, 3 months and 6 months after the finish of radiation. The middle turbinates of the animals were removed. The pathological change of the nasal mucosa were observed with scanning electron microscope, transmission electron microscope, hematoxylin and eosin (HE), alcian blue-periodic acid-Schif (AB-PAS), and Masson Trichrome (MT). The Hyp content in nasal mucosa was measured with chemo-chromatometry., Results: After radiation, the pathological characteristics in early stage (within 4 weeks) was acute inflammatory reaction. The repair of nasal mucosa started 4 weeks after radiation, lasted to 6 months. The deposition of collagen in nasal mucosa could be found 1 week after irradiation and increased gradually., Conclusion: Irradiation could induce a serials of pathological changes on nasal mucosa. The nasal mucosa fibrosis may be one of the reasons of persistent irradiation induced nasal mucosa injury.

Objective: Hematopoietic tissue is very sensitive to ionizing radiation (IR). In adult mammalian bone marrow, hematopoietic stem and progenitor cells (HSPC) reside next to the endosteal bone surface, which is lined primarily by osteoblastic cells. In the present study, we proposed to investigate the mechanisms by which osteoblasts in the hematopoietic niche regulate survival, proliferation, and differentiation of HSPC after radiation injury., Materials and Methods: Human primary CD34+ HSPC were cultured with human fetal osteoblast (hFOB) cell line cells or conditioned medium (CM) from hFOB cells with or without irradiation. Survival, apoptosis, and cell cycle were analyzed using clonogenic and flow cytometric assays. Cytokine and chemokine expression were measured by cytokine array and enzyme-linked immunosorbent assay. Their regulatory activities were assessed by quantitative real-time polymerase chain reaction, small interfering (si)RNA transfection, immunoblotting, and transbinding assays., Results: Survival of gamma-irradiated CD34+ HSPC was significantly enhanced by coculture with hFOB cells or by CM from hFOB cells. There were six factors in hFOB cell lysates and five factors released into hFOB CM enhanced by IR. IR induced phosphorylation of p53, c-Jun, and p38 and downstream p21 expression, as well as cell cycle arrest and apoptosis in hFOB cells. However, IR also induced phosphorylation of nuclear factor (NF)-kappaBp65 (ser536) and NF-kappaB activation in hFOB cells. Inhibition of NF-kappaB expression with siRNA upregulated p21, inhibited release of cytokines and chemokines, and induced hFOB and CD34+ cell apoptosis., Conclusions: NF-kappaB is a radiation-induced prosurvival factor in human osteoblastic cells. NF-kappaB gene knockdown abrogated the hematopoietic niche function of hFOB cells in supporting survival of CD34+ cells after IR.

5-Androstenediol (5-AED) stimulates hematopoiesis and enhances survival in animals exposed to ionizing radiation (IR), suggesting that this steroid may act on hematopoietic progenitor cells. We used gamma-irradiated primary human CD34(+) hematopoietic progenitor cells to show that 5-AED protects hematopoietic cells from IR damage, as shown by enhanced cell survival, clonogenicity, proliferation, and differentiation. Unlike in tumor cells, IR did not induce nuclear factor-kappaB (NFkappaB) activation in primary progenitors. However, IR stimulated IkappaB(beta) release from NFkappaB/IkappaB complexes and caused NFkappaB1 (p50) degradation. 5-AED stabilized NFkappaB1 in irradiated cells and induced NFkappaB gene expression and NFkappaB activation (DNA binding). 5-AED stimulated interleukin-6 and granulocyte colony-stimulating factor (G-CSF) secretion. The survival-enhancing effects of 5-AED on clonogenic cells were abrogated by small interfering RNA inhibition of NFkappaB gene expression and by neutralization of G-CSF with antibody. The effects of 5-AED on survival and G-CSF secretion were blocked by the NFkappaB inhibitor N-benzoyloxycarbonyl (Z)-Leu-Leu-leucinal (MG132). 5-AED had no effect on accumulation of the proapoptotic factor p53 after IR, as determined by Western blot. The results indicate that NFkappaB1 degradation after IR may be responsible for the radiation sensitivity of CD34+ cells compared with tumor cells. 5-AED exerts survival-enhancing effects on irradiated human hematopoietic progenitor cells via induction, stabilization, and activation of NFkappaB, which results in increased secretion of hematopoietic growth factor G-CSF.

There is limited understanding of CD34- hematopoietic cells and the linkage between CD34 antigen expression and cell proliferation. In this study, early CD34- CD38- LIN- (CD34-) cells were purified from mobilized adult peripheral blood and carefully analyzed in vitro for growth and modulation of CD34. Mobilized CD34+CD38- LIN- (CD34+) cells were used for comparison. Expression of CD34, CD38, and LIN antigens was determined, and proliferative responses were assessed with PKH tracking dye, expression of Ki67 antigen, and uptake of pyronin Y. Suspension cultures of adult CD34- cells generated CD34+ cells and progenitors for >8 weeks. Stromal cultures demonstrated the presence of long-term culture-initiating cells within the CD34- fraction. While CD34- cells were slower to initiate growth than the CD34+ cells were, no significant difference in hematopoietic cell output was found. Upon cultivation of CD34- cells, CD34 antigen appeared within 48 hours but was restricted to those cells that had initiated growth. Surprisingly, CD34+ precursors lost CD34 expression in culture if they remained in G0 for more than 2 days. Those cells later regained expression of CD34 antigen upon initiation of growth. Comparison of cells that did or did not rapidly modulate CD34 antigen revealed no differences in long-term growth potential. In conclusion, in vitro expression of CD34 by CD34- and CD34+ populations is tightly linked to cellular proliferation. In this culture system, expression of CD34 antigen by LIN- cells constitutes an early hallmark of growth. Measurement of CD34 expression by LIN- cells in expansion culture underestimates the total content of hematopoietic cells.