Hamster Cells Research Articles

DNA repair gene (XRCC3) polymorphisms and its association with ovarian carcinoma in Egyptian PATIENTS

The DNA repair gene polymorphisms are supposed to boost the tumorigenesis and prognosis of cancers. The X-ray repair complementing defective repair in Chinese hamster cells 3 (XRCC3) gene has a pivotal role in the DNA repair process which if mutated may be entangled in the tumorigenesis. Although there are many studies examining the DNA repair gene polymorphisms in cancers, the association of the XRCC3 SNPs with ovarian cancer in Egypt remains not fully defined. We aimed to examine the impact of the XRCC3 genetic polymorphisms with the ovarian carcinoma development and prognosis. Moreover, to analyze the relation of the SNPs alleles and haplotypes with the different tumor stages and subtypes. MethodsGenomic DNA was extracted from 50 histopathologically confirmed ovarian cancer patients and 20 cancer-free control subjects using PCR-RFLP assays. ResultsThe mean ages of the subjects were non- significantly differed between the patients and controls with significant increase with advanced tumor stage (F = 5.344, P = .003). The serous carcinoma was the most common type of ovarian tumor among our patients (40%) (X2 = 9.49, P =.023). A non-significant association was noticed between the studied SNPs (rs 861539 C > T, rs 1799794 G > A) genotypes with the ovarian cancer stages and subtypes. The rs 861539 T carriers had a higher frequency in cancer patients when compared to controls, otherwise, it showed a non-significant correlation with the tumor subtypes. The rs 861539 T/rs 1799794 A haplotype occurred at a higher frequency in ovarian cancer patients more than controls (X2 = 10.32, P = .016), with non- significant association with tumor subtypes. ConclusionDNA repair gene XRCC3 polymorphism rs 861539 T allele and the rs 861539 T/rs 1799794 A haplotype may boost the susceptibility to ovarian carcinoma with no correlation with the tumor histological subtypes and stages. They may be salutary as a DNA-based diagnostic biomarker for identifying the high-risk Egyptian females susceptible to ovarian cancer. More studies are needed to clarify the underlying mechanisms that can contribute to ovarian cancer, assess the cancer prognosis, and help to determine adequate therapy regimen.

Identification of mammalian glycoproteins with type-I LacdiNAc structures synthesized by the glycosyltransferase B3GALNT2

The type-I LacdiNAc (LDN; GalNAcβ1-3GlcNAc) has rarely been observed in mammalian cells except in the O-glycan of α-dystroglycan, in contrast to type-II LDN structures (GalNAcβ1-4GlcNAc) in N- and O-glycans that are present in many mammalian glycoproteins, such as pituitary and hypothalamic hormones. Although a β1,3-N-acetylgalactosaminyltransferase 2 (B3GALNT2; type-I LDN synthase) has been cloned, the function of type-I LDN in mammalian cells is still unclear, as its carrier protein(s) has not been identified. In this study, using HeLa cells, we demonstrate that inhibition of Golgi-resident glycosyltransferase increases the abundance of B3GALNT2-synthesized type-I LDN structures, recognized by Wisteria floribunda agglutinin (WFA). Using isotope-coded glycosylation site-specific tagging (IGOT)-LC/MS analysis of Lec8 Chinese hamster cells lacking galactosylation and of cells transfected with the B3GALNT2 gene, we identified the glycoproteins that carry B3GALNT2-generated type-I LDN in their N-glycans. Our results further revealed that LDN presence on low-density lipoprotein receptor-related protein 1 and nicastrin depends on B3GALNT2, indicating the occurrence of type-I LDN in vivo in mammalian cells. Our analysis also uncovered that most of the identified glycoproteins localize to intracellular organelles, particularly to the endoplasmic reticulum. Whereas B4GALNT3 and B4GALNT4 synthesized LDN on extracellular glycoproteins, B3GALNT2 primarily transferred LDN to intracellular glycoproteins, thereby clearly delineating proteins that carry type-I or type-II LDNs. Taken together, our results indicate the presence of mammalian glycoproteins carrying type-I LDN on N-glycans and suggest that type-I and type-II LDNs have different roles in vivo.

Identification of the fungicide epoxiconazole by virtual screening and biological assessment as inhibitor of human 11β-hydroxylase and aldosterone synthase

Humans are constantly exposed to a multitude of environmental chemicals that may disturb endocrine functions. It is crucial to identify such chemicals and uncover their mode-of-action to avoid adverse health effects. 11β-hydroxylase (CYP11B1) and aldosterone synthase (CYP11B2) catalyze the formation of cortisol and aldosterone, respectively, in the adrenal cortex. Disruption of their synthesis by exogenous chemicals can contribute to cardio-metabolic diseases, chronic kidney disease, osteoporosis, and immune-related disorders. This study applied in silico screening and in vitro evaluation for the discovery of xenobiotics inhibiting CYP11B1 and CYP11B2. Several databases comprising environmentally relevant pollutants, chemicals in body care products, food additives and drugs were virtually screened using CYP11B1 and CYP11B2 pharmacophore models. A first round of biological testing used hamster cells overexpressing human CYP11B1 or CYP11B2 to analyze 25 selected virtual hits. Three compounds inhibited CYP11B1 and CYP11B2 with IC50 values below 3 μM. The most potent inhibitor was epoxiconazole (IC50 value of 623 nM for CYP11B1 and 113 nM for CYP11B2, respectively); flurprimidol and ancymidol were moderate inhibitors. In a second round, these three compounds were tested in human adrenal H295R cells endogenously expressing CYP11B1 and CYP11B2, confirming the potent inhibition by epoxiconazole and the more moderate effects by flurprimidol and ancymidol. Thus, the in silico screening, prioritization of chemicals for initial biological tests and use of H295R cells to provide initial mechanistic information is a promising strategy to identify potential endocrine disruptors inhibiting corticosteroid synthesis. A critical assessment of human exposure levels and in vivo evaluation of potential corticosteroid disrupting effects by epoxiconazole is required.

Factors that May Protect the Native Hibernator Syrian Hamster Renal Tubular Epithelial Cells from Ferroptosis Due to Warm Anoxia-Reoxygenation.

Warm anoxia-reoxygenation induces ferroptotic cell death in mouse proximal renal tubular epithelial cells (RPTECs), whereas RPTECs of the native hibernator Syrian hamster resist cell death. Clarifying how hamster cells escape ferroptosis may reveal new molecular targets for preventing or ameliorating ischemia-reperfusion-induced human diseases or expanding the survival of organ transplants. Mouse or hamster RPTECs were subjected to anoxia and subsequent reoxygenation. Cell death was assessed with the lactated dehydrogenase (LDH) release assay and lipid peroxidation by measuring cellular malondialdehyde (MDA) fluorometrically. The effect of the ferroptosis inhibitor α-tocopherol on cell survival was assessed by the 2,3-bis (2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide (XTT) assay. The expression of the critical ferroptotic elements cystine-glutamate antiporter (xCT), ferritin, and glutathione peroxidase 4 (GPX4) was assessed by Western blot. Contrary to mouse RPTECs, hamster RPTECs resisted anoxia-reoxygenation-induced cell death and lipid peroxidation. In mouse RPTECs, α-tocopherol increased cell survival. Anoxia increased the levels of xCT, ferritin, and GPX4 in both cell types. During reoxygenation, at which reactive oxygen species overproduction occurs, xCT and ferritin decreased, whereas GPX4 increased in mouse RPTECs. In hamster RPTECs, reoxygenation raised xCT and ferritin, but lowered GPX4. Hamster RPTECs resist lipid peroxidation-induced cell death. From the three main evaluated components of the ferroptotic pathway, the increased expression of xCT and ferritin may contribute to the resistance of the hamster RPTECs to warm anoxia-reoxygenation.

Differential Innate Immune Responses Elicited by Nipah Virus and Cedar Virus Correlate with Disparate In Vivo Pathogenesis in Hamsters.

Syrian hamsters (Mesocricetus auratus) are a pathogenesis model for the Nipah virus (NiV), and we sought to determine if they are also susceptible to the Cedar virus (CedPV). Following intranasal inoculation with CedPV, virus replication occurred in the lungs and spleens of infected hamsters, a neutralizing antibody was produced in some hamsters within 8 days post-challenge, and no conspicuous signs of disease occurred. CedPV replicated to a similar magnitude as NiV-Bangladesh in type I IFN-deficient BHK-21 Syrian hamster fibroblasts but replicated 4 logs lower in type I IFN-competent primary Syrian hamster and human pulmonary endothelial cells, a principal target of henipaviruses. The coinfection of these cells with CedPV and NiV failed to rescue CedPV titers and did not diminish NiV titers, suggesting the replication machinery is virus-specific. Type I IFN response transcripts Ifna7, Ddx58, Stat1, Stat2, Ccl5, Cxcl10, Isg20, Irf7, and Iigp1 were all significantly elevated in CedPV-infected hamster endothelial cells, whereas Ifna7 and Iigp1 expression were significantly repressed during NiV infection. These results are consistent with the hypothesis that CedPV’s inability to counter the host type I IFN response may, in part, contribute to its lack of pathogenicity. Because NiV causes a fatal disease in Syrian hamsters with similarities to human disease, this model will provide valuable information about the pathogenic mechanisms of henipaviruses.

The epigenetic regulation of HsMar1, a human DNA transposon

BackgroundBoth classes of transposable elements (DNA and RNA) are tightly regulated at the transcriptional level leading to the inactivation of transposition via epigenetic mechanisms. Due to the high copies number of these elements, the hypothesis has emerged that their regulation can coordinate a regulatory network of genes. Herein, we investigated whether transposition regulation of HsMar1, a human DNA transposon, differs in presence or absence of endogenous HsMar1 copies. In the case where HsMar1 transposition is regulated, the number of repetitive DNA sequences issued by HsMar1 and distributed in the human genome makes HsMar1 a good candidate to regulate neighboring gene expression by epigenetic mechanisms.ResultsA recombinant active HsMar1 copy was inserted in HeLa (human) and CHO (hamster) cells and its genomic excision monitored. We show that HsMar1 excision is blocked in HeLa cells, whereas CHO cells are competent to promote HsMar1 excision. We demonstrate that de novo HsMar1 insertions in HeLa cells (human) undergo rapid silencing by cytosine methylation and apposition of H3K9me3 marks, whereas de novo HsMar1 insertions in CHO cells (hamster) are not repressed and enriched in H3K4me3 modifications. The overall analysis of HsMar1 endogenous copies in HeLa cells indicates that neither full-length endogenous inactive copies nor their Inverted Terminal Repeats seem to be specifically silenced, and are, in contrast, devoid of epigenetic marks. Finally, the setmar gene, derived from HsMar1, presents H3K4me3 modifications as expected for a human housekeeping gene.ConclusionsOur work highlights that de novo and old HsMar1 are not similarly regulated by epigenetic mechanisms. Old HsMar1 are generally detected as lacking epigenetic marks, irrespective their localisation relative to the genes. Considering the putative existence of a network associating HsMar1 old copies and SETMAR, two non-mutually exclusive hypotheses are proposed: active and inactive HsMar1 copies are not similarly regulated or/and regulations concern only few loci (and few genes) that cannot be detected at the whole genome level.

Rodents Versus Pig Model for Assessing the Performance of Serotype Chimeric Ad5/3 Oncolytic Adenoviruses.

Oncolytic adenoviruses (Ad) are promising tools for cancer therapeutics. Most Ad-based therapies utilize species C serotypes, with Adenovirus type 5 (Ad5) most commonly employed. Prior clinical trials demonstrated low efficiency of oncolytic Ad5 vectors, mainly due to the absence of Ad5 primary receptor (Coxsackie and Adenovirus Receptor, CAR) on cancer cells. Engineering serotype chimeric vectors (Ad5/3) to utilize Adenovirus type 3 (Ad3) receptors has greatly improved their oncolytic potential. Clinical translation of these infectivity-enhanced vectors has been challenging due to a lack of replication permissive animal models. In this study, we explored pigs as a model to study the performance of fiber-modified Ad5/3 chimeric vectors. As a control, the Ad5 fiber-unmodified virus was used. We analyzed binding, gene transfer, replication, and cytolytic ability of Ad5 and Ad5/3 in various non-human cell lines (murine, hamster, canine, porcine). Among all tested cell lines only porcine cells supported active binding and replication of Ad5/3. Syrian hamster cells supported Ad5 replication but showed no evidence of productive viral replication after infection with Ad5/3 vectors. Transduction and replication ability of Ad5/3 in porcine cells outperformed Ad5, a phenomenon often observed in human cancer cell lines. Replication of Ad5 and Ad5/3 was subsequently evaluated in vivo in immunocompetent pigs. Quantitative PCR analyses 7 days post infection revealed Ad5 and Ad5/3 DNA and replication-dependent luciferase activity in the swine lungs and spleen indicating active replication in these tissues. These studies demonstrated the flaws in using Syrian hamsters for testing serotype chimeric Ad5/3 vectors. This is the first report to validate the pig as a valuable model for preclinical testing of oncolytic adenoviruses utilizing Adenovirus type 3 receptors. We hope that these data will help to foster the clinical translation of oncolytic adenoviruses including those with Ad3 retargeted tropism.

Сравнение биологической эффективности ускоренных ионов углерода и тяжёлых ядер отдачи на клетках китайского хомячка

Сравнение биологической эффективности ускоренных ионов углерода и тяжёлых ядер отдачи на клетках китайского хомячка

Renal tubular epithelial cells of the native hibernator Syrian hamster recover more rapidly from endoplasmic reticulum stress compared to those of human or mouse following warm anoxia-reoxygenation, possibly due to increased proteasomal function

Comparative biology may reveal novel therapeutic strategies against human diseases. Ischemia‑reperfusion (IR) injury induces a number of diseases. It is known that hibernating mammals survive IR since during hibernation, prolonged periods of torpor with a marked decrease in blood flow and breathing rate are interrupted by short periods of arousal. In the present study, the differences in the characteristics of endoplasmic reticulum (ER) stress and the subsequent unfolded protein response, which are induced by IR and may cause cell death among humans, mice or the native hibernator Syrian hamster were examined in vitro using renal proximal tubular epithelial cells (RPTECs) derived from these three sources. RPTECs were subjected to anoxia or reoxygenation, both at 37˚C. Cell death was measured by LDH release assay. ER stress was assessed by determining the levels of phosphorylated protein kinase RNA‑like ER kinase, ubiquitinated proteins and Bcl‑2‑associated X protein (Bax) by western blot analysis. For proteasomal activity, a specific assay was used. The results revealed that anoxia induced ER stress in all the evaluated RPTECs, from which only the hamster‑derived RPTECs recovered during reoxygenation. Anoxia and reoxygenation increased protein ubiquitination in the human‑ and mouse‑derived RPTECs, whereas this was decreased in the hamster‑derived RPTECs. Anoxia enhanced proteasomal activity in all the evaluated RPTECs. In the human‑ and mouse‑derived RPTECs, reoxygenation reduced proteasomal activity, which remained high in the hamster‑derived RPTECs. Anoxia and reoxygenation increased Bax expression and induced cell death in the human‑ and mouse‑derived RPTECs, while neither Bax overexpression nor cell death occurred in the hamster‑derived RPTECs. Thus, on the whole, the findings of this study demonstrate that compared to human‑ or mouse‑derived RPTECs, those derived from the hamster recover more rapidly from ER stress following warm anoxia‑reoxygenation, possibly due to increased proteasomal function.

Immunogenicity of Two Plasma-Derived FVIII Products and Simoctocog Alfa in Previously Untreated Patients According to F8 Mutation Type

Background: The SIPPET study investigated inhibitor development in 251 previously untreated patients (PUPs) treated with either plasma-derived FVIII products containing von Willebrand factor (pdFVIII/VWF; n = 125), or recombinant FVIII (rFVIII; n = 126) from hamster cell lines. Amongst PUPs with non-null F8 mutations, none developed inhibitors when treated with pdFVIII/VWF while the cumulative inhibitor incidence was 43% in those treated with hamster-cell-derived rFVIII. In patients with null F8 mutations, the cumulative inhibitor incidences were 31% and 47% in patients treated with pdFVIII/VWF and rFVIII, respectively. In patients with null mutations the cumulative incidences of high-titre inhibitors were 22% and 30% with pdFVIII/VWF and rFVIII, respectively.Aim: To investigate the relationship between inhibitor development and F8 mutation type in PUPs with severe hemophilia A treated with either a rFVIII from a human cell line (Nuwiq®; simoctocog alfa) or either of two pdFVIII/VWF products, one with a VWF/FVIII ratio of 0.4 (octanate®) the other with a VWF/FVIII ratio of 1.0 (wilate®).Materials and Methods: Data from completed multicenter, prospective trials with octanate® and wilate® and interim data from the NuProtect study with Nuwiq® were analyzed. Data on F8 mutation type were available for 50/51, 27/28 and 58/66 patients in each of the studies. All patients in the three studies had no previous treatment with FVIII concentrates or other blood products containing FVIII.Results: In the three studies, 18% (9/50), 7.4% (2/27) and 19%.0% (11/58) of patients had non-null mutations. None of the patients with non-null mutations developed inhibitors with octanate®, wilate® or Nuwiq®. In patients with null mutations, 9.8% (4/41), 12.0% (3/25), and 17.0% (8/47) developed high-titre inhibitors.Conclusions: PUPs with non-null F8 mutations did not develop inhibitors when treated with octanate®, wilate® or Nuwiq®. Whilst the different studies are not directly comparable, the findings with these products, two pdFVIII/VWF and a rFVIII from a human cell line, show similar behavior to the SIPPET trial where no patients with non-null mutations treated with pdFVIII/VWF products developed inhibitors. DisclosuresLiesner:Bayer: Consultancy, Research Funding; Baxalta: Consultancy, Research Funding; Novo Nordisk: Research Funding, Speakers Bureau; Roche: Research Funding; Sobi: Speakers Bureau; Octapharma: Consultancy, Other: Clinical study investigator for NuProtect Study (Octapharma sponsored), Research Funding, Speakers Bureau. Versteden:Octapharma AG: Employment. Lowndes:Octapharma AG: Employment. Belyanskaya:Octapharma AG: Employment. Oldenburg:Grifols: Honoraria, Research Funding; Novo Nordisk: Honoraria, Research Funding; Biotest: Honoraria, Research Funding; Biogen: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Roche: Honoraria, Research Funding; Octapharma: Honoraria, Research Funding; Shire: Honoraria, Research Funding; CSL Behring: Honoraria, Research Funding; Bayer: Consultancy, Honoraria, Research Funding; Chugai: Honoraria, Research Funding; Swedish Orphan Biovitrum: Honoraria, Research Funding. Pavlova:Novo Nordisk: Honoraria; Octapharma: Honoraria.

Cell Death Patterns Due to Warm Ischemia or Reperfusion in Renal Tubular Epithelial Cells Originating from Human, Mouse, or the Native Hibernator Hamster.

Ischemia–reperfusion injury contributes to the pathogenesis of many diseases, with acute kidney injury included. Hibernating mammals survive prolonged bouts of deep torpor with a dramatic drop in blood pressure, heart, and breathing rates, interspersed with short periods of arousal and, consequently, ischemia–reperfusion injury. Clarifying the differences under warm anoxia or reoxygenation between human cells and cells from a native hibernator may reveal interventions for rendering human cells resistant to ischemia–reperfusion injury. Human and hamster renal proximal tubular epithelial cells (RPTECs) were cultured under warm anoxia or reoxygenation. Mouse RPTECs were used as a phylogenetic control for hamster cells. Cell death was assessed by both cell imaging and lactate dehydrogenase (LDH) release assay, apoptosis by cleaved caspase-3, autophagy by microtubule-associated protein 1-light chain 3 B II (LC3B-II) to LC3B-I ratio, necroptosis by phosphorylated mixed-lineage kinase domain-like pseudokinase, reactive oxygen species (ROS) fluorometrically, and lipid peroxidation, the end-point of ferroptosis, by malondialdehyde. Human cells died after short periods of warm anoxia or reoxygenation, whereas hamster cells were extremely resistant. In human cells, apoptosis contributed to cell death under both anoxia and reoxygenation. Although under reoxygenation, ROS increased in both human and hamster RPTECs, lipid peroxidation-induced cell death was detected only in human cells. Autophagy was observed only in human cells under both conditions. Necroptosis was not detected in any of the evaluated cells. Clarifying the ways that are responsible for hamster RPTECs escaping from apoptosis and lipid peroxidation-induced cell death may reveal interventions for preventing ischemia–reperfusion-induced acute kidney injury in humans.

Energy handling in renal tubular epithelial cells of the hamster, a native hibernator, under warm anoxia or reoxygenation.

Ischemia-reperfusion (I-R) injury causes several diseases, including acute kidney injury. Hibernating mammals survive periods of torpor with a marked drop in tissue perfusion, interspersed with periods of arousal, and consequently I-R injury. In the present study, sensitivity to anoxia and/or reoxygenation and alterations in cellular ATP and homeostasis of the two most energy consuming processes, protein translation and Na+-K+-ATPase function, were evaluated in renal proximal tubular epithelial cells of mouse or native hibernator hamster origin. Compared with the mouse cells, the hamster cells were less sensitive to anoxia and reoxygenation and ATP was preserved under anoxia. Anoxia triggered mechanisms that suppress protein translation in both species. However, under anoxia, the activity of ATPase, which is mostly attributed to Na+-K+-ATPase function, remained stable in the hamster cells but decreased in the mouse cells. In normoxia, ATPase activity in hamster cells was considerably lower than that in mouse cells. As the Na+-K+-ATPase pump preserves the ion gradient against passive leakage through ion channels, the lower energy demand for the function of this pump in hamster cells may indicate less ion leakage due to fewer ion channels. In accordance with this hypothesis, ouabain-treated hamster cells had a higher survival rate than mouse cells, indicating fewer ion channels and consequently slower deregulation of intracellular ion concentration and cell death due to Na+-K+-ATPase inhibition. Therefore, it is likely that the conserved energy from the suppression of protein translation is adequate enough to support the lower energy demand for Na+-K+-ATPase function and cell survival of hamster cells under anoxia. Clarifying how cells of a native hibernator manage energy under warm I-R may reveal novel and possible clinically applicable pathways for preventing I-R injury.

Collaborative study of thresholds for mutagens: proposal of a typical protocol for detection of hormetic responses in cytotoxicity tests

BackgroundAccording to the linear no-threshold model (LNT), even the smallest amount of radiation is hazardous. Although the LNT is not based on solid data, this hypothesis has been applied to mutagens and carcinogens. As a result, it has been postulated that there are no thresholds for these chemicals. To demonstrate negativity by experiments is practically impossible, because negative data may leave behind the possibility that additional data might make the resolution power high enough to change negativity to positivity. Furthermore, additional data collection may be endless and we may be trapped in agnosticism. When hormesis is established, in which biological responses are higher at low-doses and lower at high-doses than the control, thresholds could be established between the low- and high-doses. Before examination of thresholds in chemical mutagenesis, hormetic responses in cytotoxicity were tested using cultured mammalian cells.MethodHuman cells (HeLa S3 and TK6) or Chinese hamster cells (CHL/IU) were cultured in 96-well plates and treated with mitomycin C (MMC) or ethyl methanesulfonate (EMS) at various dose levels and optical density was measured after addition of a reagent to detect cellular activity. In hormetic responses, data might fluctuate to and fro; therefore, experimental conditions were examined from various aspects to eliminate confounding factors including cell numbers, detection time, the edge effect of 96-well plates, and measurement time after addition of the reagent for detection.ResultsThe dose response relationship was never linear. Cellular activities after treatment with MMC or EMS were generally higher at lower doses levels and lower at higher doses than the control, showing hormesis and allowing the establishment of thresholds. Dose response curves sometimes showed two or three peaks, probably reflecting different cellular responses.ConclusionHormetic responses in cytotoxicity tests were observed and thresholds could be established. Based on the results of this investigation, we put forward a tentative protocol to detect chemical hormesis in cytotoxicity tests, i.e., inoculate 2000 cells per well, add various doses of a test chemical 48 h after inoculation, add a detection dye 10 h after treatment, and measure optical density 2 h after addition of the reagent for detection.

Influence of chromatin remodeling in the removal of UVC-induced damage in TCR proficient and deficient Chinese hamster cells

In mammalian cells, nucleotide excision repair system is constituted of two sub-pathways, global genomic repair (GGR) and transcription coupled repair (TCR). Deficiency of TCR pathway leads to Cockyane syndrome (CS) which is a rare human autosomal recessive disorder. Owing to the pivotal role of CSB gene in TCR, it’s mutation causes severe repair and transcriptional defects in CSB patients. CSB protein belongs to the ATP chromatin remodeling complex, hence presumably an improper chromatin remodeling in CSB cells could be at the source of inefficient removal of pyrimidine dimers (CPDs) after UVC exposure in these patients. In this study, we evaluated the role of chromatin remodeling process on UVC induced CPDs and the ensuing effect on chromosomal aberrations in UV61 cells (TCR deficient) and its parental cell line, AA8 (TCR proficient). We observed that post 2 h UVC irradiation, both cell lines underwent pronounced chromatin relaxation but was lower in CSB deficient UV61 cells. Since the deficiency in chromatin remodeling in CSB-mutated cells was accompanied by a decrease in the histone acetylation level, the histone deacetylase inhibitor trichostatin A (TSA) was employed to improve the removal of UVC-induced lesions by increasing the histone acetylation level. Contrary to expectations, TSA increased the induction of chromosomal aberrations and apoptotic cells along with amounts of CPDs after UVC-irradiation, indicating that changes in histone acetylation levels might contribute to the failure in the removal of UVC-induced lesions. Also, it has been shown earlier that the expression of genes regulated by CSB is affected by the increase in the acetylation level produced by TSA. Taken all together, we hypothesize that failure in the removal of UVC induced lesions in CSB-deficient cells can be caused by an imbalance in histone acetylation levels leading to chromatin conformation changes and hence interaction defects among repair proteins and DNA lesions.

Spermatogenesis after transplantation of adipose tissue-derived mesenchymal stem cells in busulfan-induced azoospermic hamster.

Objective(s):Adipose tissue-derived mesenchymal stem cells (AT-MSCs) with more potent immunomodulatory effects, greater proliferative potential and secretion of growth factors and cytokines in comparison with bone marrow derived MSCs are more appropriate for cell therapy. The aims of the present study were to evaluate the histomorphometric effect of AT-MSCs allotransplantation on regeneration of germinal layer cells of seminiferous tubules in busulfan-induced azoospermic hamsters.Materials and Methods: In the present experimental case-control study, AT-MSCs were isolated from adipose tissue of two female and six male donor albino hamsters, and testes of the males were simultaneously used as negative control group. Six mature male recipient hamsters received two doses of busulfan with three weeks interval to stop endogenous spermatogenesis. Right testis of hamsters was intratubular injected with AT-MSCs via efferent duct 35 days after induction of azoospermia and was used as cell therapy group. The left testis without cell therapy was served as azoospermia group.Results:After 35 days, testes and epididymis in all groups were removed for histological evaluation. Histomorphometric analyses of AT-MSCs-treated testes and epididymis showed that the epithelial tissue of seminiferous tubules was normally repaired in most cell-treated seminiferous tubules, and spermatozoa were present in epididymis tubes in comparison with intact testes. The untreated seminiferous tubules and epididymis tubes of azoospermia group were empty.Conclusion:Allotransplanted AT-MSCs could successfully induce spermatogenesis in azoospermic seminiferous tubules of hamster. Therefore, AT-MSCs can be suggested as an attractive candidate in cell transplantation of azoospermia.

Abstract 261: Chemopreventive effects of flavonoids on pancreatic carcinogenesis

Abstract Although clinical therapies are being developed for combating pancreatic cancer, its prognosis remains dismal; consequently, chemopreventive strategies may be needed to manage this disease. Luteolin (Lut), a flavone contained in perilla, is one of the most effective antioxidant flavonoids and has demonstrated potential for the treatment of inflammatory and neoplastic disease. Hesperetin (Hes) is a flavone contained in citrus, and the Ohsaki cohort study showed that citrus consumption was correlated with reduced pancreatic cancer (RR=0.62, 95%CI=0.38-1.00) (Int.J.Cancer, 2010: Li.W). However, there are no studies dealing with their antineoplastic effects against pancreatic cancer. In the present study, to assess the chemopreventive effects of Lut and Hes for pancreatic carcinogenesis, 6 week-old syrian golden hamsters were subcutaneously injected with N-nitrsobis(2-oxopropyl)amine four times and then fed Quick Fat Diet (control, n=14) or Quick Fat Diets with Lut 100 ppm (n=13) or Hes 100 ppm, 1000 ppm (n=13,13) for 13 weeks. There were no differences in body weights or liver or kidney weights among the groups. Serum cholesterol was significantly decreased in the Lut group. The incidence and multiplicity of pancreatic cancer was significantly suppressed in the Lut group (Incidence/ Multiplicity: 23%/ 0.23±0.44; P<0.05), but not the Hes groups (100ppm: 54%/ 0.69±0.75, 1000ppm: 62%/ 0.77±0.73), compared to the controls (71%/ 0.93±0.73). The Ki67 labeling index in pancreastic intraepithelial neoplasias (PanINs) was significantly decreased by Lut, but not Hes. Therefore, we focused further investigation on Lut. In vitro, cell proliferation of both hamster (HPD1NR) and human (MiaPaCa, PANC1) pancreatic cancer cell lines was inhibited by Lut in a dose-dependent manner. Multi-blot analysis for phosphorylated proteins related to cell signaling revealed that phosphorylated forms of Stat3 (tyr705) were down-regulated by Lut in MiaPaCa and PANC1 cells. We confirmed them in a dose-dependent manner in the three pancreatic cell lines and also found that Lut down-regulated cyclin D1. In vivo, the nuclear positive proportion of pStat3 (tyr705) in both PanINs and adenocarcinomas was significantly decreased by Lut. Because pStat3 (tyr705) is regulated by cytokines such as Il6, we examined mRNA levels of several cytokines including Il6 in hamster pancreatic tissues. Lut decreased the mRNA expression of Tgfb, Tnfa, Il10, and Il6. Immunohistochemistry of alpha smooth muscle actin revealed that the positive area of activated pancreatic stellate cells, which can produce these cytokines in cancerous tissue, tended to be decreased by Lut. In conclusion, these results indicate that Lut, but not Hes, has potential as a chemopreventive agent for pancreatic cancer and inhibition of pStat3 signaling may be involved in its mechanism of action. Citation Format: Hiroyuki Kato, Aya Naiki, Shugo Suzuki, Yoriko Yamashita, Satoru Takahashi. Chemopreventive effects of flavonoids on pancreatic carcinogenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 261.

Impairment of the Viability of Transformed Chinese Hamster Cells in a Nonsubcultured Culture under the Influence of Exogenous Oxidized Guanoside is Manifested Only in the Stationary Phase of Growth

Despite the fact that oxidation products of nucleotides and nucleosides are markers of oxidative stress, reports of the paradoxical ability of these compounds to protect cells from the harmful effects of reactive oxygen species began to appear more often. Among all nitrogenous bases, guanine is most susceptible to the influence of oxidative stress; therefore, guanosine is oxidized more often than other bases. In the present work, the effect of exogenous 8-oxo-2′-deoxyguanosine on the growth and “stationary phase aging” (accumulation of “age-related” changes in cultured cells during cell proliferation slowing down within a single passage and subsequent “aging” in the stationary growth phase) of nonsubcultured transformed Chinese hamster cells was studied. We showed that the nucleoside is rapidly absorbed by the cells from the medium, but it does not affect the growth of the culture, and impairs the viability of the cells in the late stationary growth phase. Thus, no mitogenic or geroprotective effect of 8-oxo-2′-deoxyguanosine was found.

Abstract 5914: The porcine model for onocolytic adenovirus-based therapy

Abstract Oncolytic adenoviruses (Ad) are promising tools in the development of cancer therapeutics. A majority of Ad-based therapies utilize serotypes of species C, with Adenovirus type 5 (Ad5) being the most commonly employed. Previously, clinical trials have demonstrated the low efficiency of Ad5 vectors, mainly due to absence of the Ad5 primary receptor (Coxsackie Adenovirus Receptor, CAR) in cancer cells. Engineering Ad vectors utilizing the species B (Ad3, Ad35, Ad11) receptors have greatly improved the oncolytic potential of Ad-based therapies. However, the lack of a viable animal model has impeded clinical translation of these tropism-modified vectors. Mouse models are insufficient because Ad does not replicate in murine tissue. Non-human apes are not feasible due to availability and cost. Cotton rats and Syrian hamsters, although permissive of Ad5 replication, are not suitable for Ad3-, Ad35-, and Ad11-retargeted vectors due to the lack of species B primary receptors (CD46 and desmoglein 2) in rodent systems. In this study, we explored pigs as a model to study performance of the group B oncolytic adenoviruses by employing the fiber-modified Ad5/Ad3 chimeric vector. As a control, the Ad5 fiber-unmodified virus was used. First, we demonstrated the ability of swine cell lines to support replication of both Ad5 and Ad5/Ad3. Second, we analyzed binding, gene transfer, cytolytic, and replication ability of Ad5 and Ad5/Ad3 in various non-human cell lines (swine, hamster, murine, rat, bovine, canine). Our data confirmed that while hamster cell lines (HP1 and HapT1) were able to support binding and replication of Ad5-based vectors, they failed to support that with the Ad3-retargeted vectors. Additionally, we showed that among all tested cell lines, only porcine cells (PK15 and PTK75) were supportive of both binding and replication of the Ad3-retargeted virus. Of note, Ad5/Ad3 outperformed Ad5 in its cytolytic effect in porcine cell lines. These in vitro results prompted evaluation of the vectors in vivo. Immunocompetent Yorkshire pigs were systemically injected with a single dose of Ad5- and Ad5/3- expressing luciferase (Luc) from the Ad E3 region. Quantitative PCR analyses of the primary organs collected 7 days post-infection revealed Ad5 and Ad5/3 viral DNA in the lungs and spleen. Replication-dependent Luc expression was also observed in these tissue samples suggesting active viral replication. The quantity of viral DNA in other tissue such as the kidneys, liver, and pancreas was negligible. The results of these in vitro and in vivo studies indicate that pigs are a promising model to assess unmodified and tropism-modified adenoviral vectors. Citation Format: Malavika Chandrashekar, Lisa Koodie, Michele Dunning, George Ruth, Richard Bianco, Masato Yamamoto, Julia Davydova. The porcine model for onocolytic adenovirus-based therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5914.

Effect of extraction Alkaloids from Zephyranthes candida induces cell death through destruction microtubules in (China hamster cell line)

Background: In eukaryotic cells the cytoskeleton network consists of three major structural elements, microtubules, microfilament,and intermediate filaments. Tubulin is the basic protein of the MTs, molecules of tubulin arranged in dimmers consisting of two forms, α- tubulin and β-tubulin. They are continuously changeable structures.Taxanes and vinca alkaloids are inhibitors MTC that destabilize microtubules, there by suppressing their dynamics which required for proper mitotic function and effectively blocking cell regulation progression resulting in cell death. Objective: To evaluate the capability of alkaloids taken away from leaves of Zephyranthes candidato divert the MTC network of (CHO), which is an aggressive metastasis cell line. Patients and Methods: In our experiments we used the mouse CHO cell line. This cell line was obtained from the Department of Biology,Faculty of Medicine, Wuhan University, China. The cells were grown in Dulbecco’s Minimal Essential Medium (DMEM) (PAA Laboratories GmbH, Linz, Austria), supplemented with 10% fetal bovine serum, 2 mM glutamine, 100 Uml–1 penicillin, and 100 μg ml–1 streptomycin (PAA Laboratories, Austria) in a humidified atmosphere of 95 % air and 5 % CO2 at 37 °C.Zephyranthes candida crude alkaloid extract treated cells were cultivated over microscopic cover slips, washed three Times for 4 min with PBS (pH 6.9) and fixed by 3% paraformaldehydein PBS. The ability of alkaloid extract to inhibit CHO tumor cells growth in vivo was assessed; forty mice were injected subcutaneouslyin the right dorsal with this tumor cells, after the tumor developed to 8-1 mm2, and eliminating the animalsthat did not develop tumors, the animals were divided to three groups each one with ten individuals. Results: The extractor was capable of divert the MTC of the cells below realization after 1hr of in sinuation in a focus as little as possible 20 μg/ml. while DAPI staining used, the cells death was not check in this focus and time. The cell death have been spotted when the focus of the alkaloid reproducer raised up to 80 and 100 μg/ml through the aforesaid exposure time. The cells were able to improving there native MTC contraction after 12 hr of the alkaloid deletion. The excerpt focus of 1mg/Kg/Bw competently prevent CHO cell line cancer development in vivo to 97.14% after 3 weeks therapy contrast to natural control. Conclusion: The invasive species H22 cells offer changesin the preparation of their MTC at a focus of Zephyranthes candida leaf alkaloids excerpt as low as 20 μg/ml focus after 1hr of exposuretime.

Multiple Click-Selective tRNA Synthetases Expand Mammalian Cell-Specific Proteomics.

Bioorthogonal tools enable cell-type-specific proteomics, a prerequisite to understanding biological processes in multicellular organisms. Here we report two engineered aminoacyl-tRNA synthetases for mammalian bioorthogonal labeling: a tyrosyl ( ScTyrY43G) and a phenylalanyl ( MmPheT413G) tRNA synthetase that incorporate azide-bearing noncanonical amino acids specifically into the nascent proteomes of host cells. Azide-labeled proteins are chemoselectively tagged via azide-alkyne cycloadditions with fluorophores for imaging or affinity resins for mass spectrometric characterization. Both mutant synthetases label human, hamster, and mouse cell line proteins and selectively activate their azido-bearing amino acids over 10-fold above the canonical. ScTyrY43G and MmPheT413G label overlapping but distinct proteomes in human cell lines, with broader proteome coverage upon their coexpression. In mice, ScTyrY43G and MmPheT413G label the melanoma tumor proteome and plasma secretome. This work furnishes new tools for mammalian residue-specific bioorthogonal chemistry, and enables more robust and comprehensive cell-type-specific proteomics in live mammals.