Cytogenetic effect of some nanostructure polymers prepared via gamma irradiation on Vicia faba plant

Background Nourishment plants during the field time is a must; to have healthy, high productive and self-propagating plants. The trendy nano-fertilizers came to the front in modernized agriculture seeking for minimizing the soil suffocation with other chemical fertilizers in the bulk size. Nano-fertilizers may represent a way out of shot as they are completely absorbed by plant due to their small size, also it magnifies the benefit to the plant due to its high surface area. Nano-fertilizers are introduced via different way of synthesis methods. In this work, three of new nanocomposites are prepared in nano form via Gamma irradiation from Cobalt 60 source at irradiation dose 5 KGy. These composites which can supply plants with P, Zn elements needs to be revised for their safety usage in agriculture. Methodology Three compounds; Zinc oxide, phosphorous and the mixed Zinc–phosphorous elements were prepared in nano-composite forms coated with PVP as a shell and then characterized by HR-TEM, UV and FT-IR to emphasize their new sizes and shapes, then, they were examined for their cytotoxicity in three concentrations (0.5, 1 and 2%) on Vicia faba plants; after 3 h of direct roots treatment. Cytotoxicity test concerned the mitotic index, phase index, abnormal mitosis and the type of the aberrations at each phase. Results The three tested NPs exerted mito-accelerating effect on root meristematic cells. However, concentration‐dependent genotoxicity was also an evident. Conclusion The three examined nano-composites may recommend to be used in the lowest examined concentrations to minimize its harm effect on the plant cell and keep their benefits to the environment. It also recommended to count the Zn/P mix NPs over ZN or P separately as it induces an intermediating cytogenetic effect on mitosis apparatus of Vicia faba plant. Graphical Abstract

PATH-11. PDGFA INITIATES ABERRANT MITOSIS AND MALIGNANT TRANSFORMATION OF NEURAL PROGENITOR CELLS

BACKGROUND Imagining ways to prevent or treat glioblastoma (GBM) have been hindered by a lack of understanding of its pathogenesis. Although platelet derived growth factor-A (PDGFA) overexpression may be an early event, critical details of the biology of GBM, and tools to study its initiation have been lacking. Indeed, many PDGF-driven models replicate its microscopic appearance, but not genomic architecture. Recently, we reported an in vitro model of GBM initiation that overcomes this barrier to authenticity. METHODS We used a method developed to establish neural stem cell cultures to investigate the effects of PDGF-A on cells derived from the subventricular zone (SVZ), a putative region where the cells of origins for GBM are derived. We micro-dissect SVZ tissue from p53-null and wild-type adult mice, culture cells in media supplemented with PDGF-A, and assess cell viability, proliferation, mitotic capacity, and genome stability. RESULTS Paradoxical to its canonical role as a growth factor, we observe abrupt and substantial cell death in PDGF-A. Abnormal mitosis was the first observable alteration and occurred immediately in cells of both p53 wild-type and null genotypes: wild-type cells did not survive in PDGF-A, whereas a fraction of null cells evade apoptosis. Evading cells displayed attenuated proliferation accompanied by early chromosomal gains and losses. After approximately 100 days in PDGF-A, surviving cells suddenly proliferate rapidly, acquire growth factor independence, and become tumorigenic in immune-competent mice. Transformed cells continue to display highly abnormal mitotic phenotypes with complex karyotypes similar to GBM, had a neural progenitor cell (NPC) lineage profile, and were resistant to PDGFR-alpha inhibition. CONCLUSION Abnormal mitosis induced by PDGF-A initiates and perpetuates the genome instability that transforms p53-null neural progenitor cells to yield cancers with the types of recurring chromosomal gains and losses that characterize human GBM.

M2 Muscarinic Receptor Activation Impairs Mitotic Progression and Bipolar Mitotic Spindle Formation in Human Glioblastoma Cell Lines

Background: Glioblastoma multiforme (GBM) is characterized by several genetic abnormalities, leading to cell cycle deregulation and abnormal mitosis caused by a defective checkpoint. We previously demonstrated that arecaidine propargyl ester (APE), an orthosteric agonist of M2 muscarinic acetylcholine receptors (mAChRs), arrests the cell cycle of glioblastoma (GB) cells, reducing their survival. The aim of this work was to better characterize the molecular mechanisms responsible for this cell cycle arrest. Methods: The arrest of cell proliferation was evaluated by flow cytometry analysis. Using immunocytochemistry and time-lapse analysis, the percentage of abnormal mitosis and aberrant mitotic spindles were assessed in both cell lines. Western blot analysis was used to evaluate the modulation of Sirtuin2 and acetylated tubulin—factors involved in the control of cell cycle progression. Results: APE treatment caused arrest in the M phase, as indicated by the increase in p-HH3 (ser10)-positive cells. By immunocytochemistry, we found a significant increase in abnormal mitoses and multipolar mitotic spindle formation after APE treatment. Time-lapse analysis confirmed that the APE-treated GB cells were unable to correctly complete the mitosis. The modulated expression of SIRT2 and acetylated tubulin in APE-treated cells provides new insights into the mechanisms of altered mitotic progression in both GB cell lines. Conclusions: Our data show that the M2 agonist increases aberrant mitosis in GB cell lines. These results strengthen the idea of considering M2 acetylcholine receptors a novel promising therapeutic target for the glioblastoma treatment.

Origins of cancer genome complexity revealed by haplotype-resolved genomic analysis of evolution of Barretts esophagus to esophageal adenocarcinoma

Complex chromosomal alterations are a hallmark of advanced cancers but rarely seen in normal tissue. The progression of precancerous lesions to malignancy is often accompanied by increasing complexity of chromosomal alterations that can drive their transformation through focal oncogenic amplifications. However, the etiology and evolution dynamics of these alterations are poorly understood. Here we study chromosomal copy-number evolution in the progression of Barretts esophagus (BE) to esophageal adenocarcinoma (EAC) by multi-regional whole-genome sequencing analysis of BE samples with dysplasia and microscopic EAC foci. Through haplotype-specific copy-number analysis of BE genome evolution, we identified distinct patterns of episodic copy-number evolution consistent with the outcomes of abnormal mitosis and dicentric chromosome breakage. While abnormal mitosis, including whole-genome duplication, accounts for most chromosome or arm-level copy-number changes, segmental copy-number alterations display signatures of multi-generational evolution of unstable dicentric chromosomes. Continuous evolution of dicentric chromosomes through breakage-fusion-bridge cycles and chromothripsis rapidly increases genomic complexity and diversity among BE cells, culminating in the generation of distinct focal amplifications. These mutational processes enable multiple subclones within small dysplastic areas to undergo parallel transformation to cancer following acquisition of distinct oncogenic amplifications. Our results demonstrate how chromosomal instability drives clonal diversification in precancer evolution and promotes tumorigenesis in primary human samples.

Age and Gender in Relation to Colorectal Cancer in Najef Province: A Histopathological Study

Colorectal cancer (CRC), which is also referred to colorectal adenocarcinoma, occurs when the growth of cells goes out of control in the colon or rectum. A number of histological colorectal carcinoma are listed, such as mucinous, signet ring cell, and moderately differentiated adenocarcinoma. The present study included fifty tissue blocks (16 females and 34 males) of patient groups with CRC and thirty five tissue blocks of colon tissue (ulcerative colitis) which were used as control group. The mean age of patients group was 51.44±16.67 years. The majority of patients with colonic carcinoma were above the age of 40, accounting for 80%, while 20% of cases were below the age of 40 years. A recto-sigmoid location is the most common site for colonic tumors accounting for 60%. Grade of tumor was well differentiated in 56%, and the following features were observed: The tissue appears with multi-layering, back to back arrangement (little intervening stroma), loss of polarity, loss of goblet cells, and invasion of stroma and presence of nuclear criteria of malignancy: hyperchromatism, high N/C ratio visible nucleoli and abnormal mitosis. The present results also showed that in grade I lesion, most of tumor retains glandular pattern, moderately differentiated in 28%, and tumor is nearly equally composed of glandular and solid patterns. However the poorly differentiated was 16% with same cellular criteria of malignancy but almost all the tumor was composed of solid areas. The present findings divided the stage of tumor patients into: 22% stage I; 66% stage II, and 12% stage III.

Detection of large extracellular silver nanoparticle rings observed during mitosis using darkfield microscopy

During studies on the absorption and interactions between silver nanoparticles and mammalian cells grown in vitro it was observed that large extracellular rings of silver nanoparticles were deposited on the microscope slide, many located near post-mitotic cells. Silver nanoparticles (AgNP, 80nm), coated with citrate, were incubated at concentrations of 0.3 to 30 μg/ml with a human-derived culture of retinal pigment epithelial cells (ARPE-19) and observed using darkfield and fluorescent microscopy, 24 h after treatment. Approximately cell-sized extracellular rings of deposited AgNP were observed on the slides among a field of dispersed individual AgNP. The mean diameter of 45 nanoparticles circles was 62.5 +/-12 microns. Ring structures were frequently observed near what appeared to be post-mitotic daughter cells, giving rise to the possibility that cell membrane fragments were deposited on the slide during mitosis, and those fragments selectively attracted and retained silver nanoparticles from suspension in the cell culture medium. These circular structures were observable for the following technical reasons: 1) darkfield microscope could observe single nanoparticles below 100 nm in size, 2) a large concentration (108 and 109) of nanoparticles was used in these experiments 3) negatively charged nanoparticles were attracted to adhesion membrane proteins remaining on the slide from mitosis. The observation of silver nanoparticles attracted to apparent remnants of cellular mitosis could be a useful tool for the study of normal and abnormal mitosis.

The dietary flavonoid eupatilin attenuates in vitro lipid peroxidation and targets lipid profile in cancer HeLa cells

Eupatilin, a dietary flavonoid, is an antioxidant agent against membrane lipid oxidative damage and induces cytotoxicity, apoptosis and abnormal mitosis, affecting lipid profile and mitochondrial potential in cancer HeLa cells.

Chromosomes function as a barrier to mitotic spindle bipolarity in polyploid cells

Whole genome duplications (WGDs) are found in a variety of tumors and are associated with chromosomal instability (CIN) and poor prognosis [1,2]. When induced experimentally, through cytokinesis failure, polyploid cells generate tumors [3]. Cytokinesis failure results in the accumulation of double DNA content, but also of cytoplasmic organelles, such as centrosomes, which are the major microtubule (MT) organizing centers of animal cells. Importantly, even if there is a correlation between polyploidy and CIN [4], the underlying mechanisms generating error-prone mitosis in cells with extra DNA and extra centrosomes are not known. When considering polyploid mitosis, it is essential to take into account the increase in MT nucleation due to the presence of extra centrosomes and extra DNA. The presence of supernumerary centrosomes in a cell, centrosome amplification [5], is associated with mitotic spindle multipolarity and CIN [6–9]. Importantly, additional MTs can be nucleated from the chromatin (chromatin mediated pathway-CMP) or from pre-existing MTs-through the Augmin pathway. We hypothesized that the increase in DNA and centrosome content in a cell could lead to an increased MT mass, which might account for abnormal mitosis described in polyploid cells [4, 10, 11, 12]. Using genetics, live imaging and modeling approaches, we investigated the mechanisms establishing multipolarity in vivo in polyploid cells. We found that MT nucleation from the centrosomes is the major contributor to multipolarity, while other pathways seem to play minor roles. Unexpectedly, we found that even if Ncd/HSET, plays an essential role in promoting centrosome clustering in early mitosis, the increase in chromosome mass associated with cytokinesis failure functions as a barrier to centrosome clustering into two main poles. Our work provides a mechanistic link between polyploidy and the generation of CIN.