Decreased Cell Division Research Articles

Transcriptome sequencing-based analysis of primary vein development in Betula pendula ‘Dalecarlica’

Keymessage The study revealed the major biological processes occurred at three developmental stages and identified candidate genes involved in primary vein development of birch plants.Vascular tissues usually mirror the surrounding leaf shape and its development plays a fundamental role in plant performance. However, the information of vascular development in birch trees, especially primary vein development, remains unclear. Therefore, we conducted the anatomical observation on primary veins from leaves at different development stages in Betula pendula ‘Dalecarlica’. With the development of primary vein, dynamic changes in mechanical tissue thickness and primary vein diameter were consistent with each other, and the sum of phloem, xylem and cambium thickness was significantly varied. Transcriptome analysis indicated that primary vein development could be divided into three stages, namely Stage I, II and III, which were in aggreement with anatomical observation. Expression of marker genes associated with vascular tissues revealed that pro-vasculature development occurred at Stage I and II, and phloem development occurred at Stage III. GO enrichment analysis of differentially expressed genes (DEGs) showed that shared DEGs at Stage II were mainly engaged in cell division and cell cycle, and shared DEGs at Stage III were mainly engaged in phosphorylation. Decreased cell division and cell cycle as well as activation of lignin biosynthesis might contribute to primary vein development. Combining phenotypic traits, we performed weighted gene co-expression network analysis and identified a cytochrome P450 84A (CYP84A) family gene (BpF5H1). Based on analyses of gene families, expression patterns and yeast-two hybrid assay results, we proposed a potential electron transfer pathway involving BpF5H1 and three cytochrome b5 proteins during primary vein development in B. pendula ‘Dalecarlica’. These results could shed some light on which biological processes occurred during primary vein formation and provide some valuable clues for vascular morphogenesis in woody plants.

Ovatodiolide inhibits endometrial cancer stemness via reactive oxygen species-mediated DNA damage and cell cycle arrest

Endometrial cancer (EC) is a common gynecological cancer worldwide, often associated with a poor prognosis after recurrence or metastasis. Ovatodiolide (OVA) is a macrocyclic diterpenoid derived from Anisomeles indica that shows anticancer effects in various malignancies. This study aimed to evaluate the cytotoxic effects of OVA on EC cell proliferation and cancer stem cell (CSC) activity and explore its underlying molecular mechanisms. OVA treatment dose-dependently reduced the viability and colony formation of three EC cell lines (AN3CA, HEC-1A, and EMC6). It induced G2/M phase cell cycle arrest, associated with decreased cell division cycle 25C (CDC25C) expression and reduced activation of cyclin-dependent kinases 1 (CDK1) and 2 (CDK2). OVA also increased reactive oxygen species (ROS) production and DNA damage, activating the DNA damage-sensitive cell cycle checkpoint kinases 1 (CHK1) and 2 (CHK2) and upregulating the DNA damage marker γ-H2A.X variant histone (H2AX). It also suppressed the activation of mechanistic target of rapamycin kinase (mTOR) and nuclear factor kappa B (NF-κB) and downregulated glutathione peroxidase 1 (GPX1), an antioxidant enzyme counteracting oxidative stress. Moreover, OVA reduced the self-renewal capacity of CSCs, reducing the expression of key stemness proteins Nanog homeobox (NANOG) and octamer-binding transcription factor 4 (OCT4). The ROS inhibitor N-acetylcysteine attenuated the anti-proliferative and anti-CSC effects of OVA. Our findings suggest that OVA acts via ROS generation, leading to oxidative stress and DNA damage, culminating in cell cycle arrest and the suppression of CSC activity in EC. Therefore, OVA is a promising therapeutic agent for EC, either as a standalone treatment or an adjunct to existing therapies.

Hydrogen peroxide modulates the expression of the target of rapamycin (TOR) and cell division in Arabidopsis thaliana.

Hydrogen peroxide (H2O2) is naturally produced by plant cells during normal development and serves as a messenger that regulates cell metabolism. Despite its importance, the relationship between hydrogen peroxide and the target of rapamycin (TOR) pathway, as well as its impact on cell division, has been poorly analyzed. In this study, we explore the interaction of H2O2 with TOR, a serine/threonine protein kinase that plays a central role in controlling cell growth, size, and metabolism in Arabidopsis thaliana. By applying two concentrations of H2O2 exogenously (0.5 and 1mM), we could correlate developmental traits, such as primary root growth, lateral root formation, and fresh weight, with the expression of the cell cycle gene CYCB1;1, as well as TOR expression. When assessing the expression of the ribosome biogenesis-related gene RPS27B, an increase of 94.34% was noted following exposure to 1mM H2O2 treatment. This increase was suppressed by the TOR inhibitor torin 2. The elimination of H2O2 accumulation with ascorbic acid (AA) resulted in decreased cell division as well as TOR expression. The potential molecular mechanisms associated with the effects of H2O2 on the cell cycle and TOR expression in roots are discussed in the context of the results.

Untangling the Impacts of Ethanol on Myoblast Proliferation

Alcohol-mediated myopathy frequently accompanies chronic alcohol misuse. This decreased skeletal muscle mass and function increases risk for frailty and falls, decreases quality of life, and worsens prognosis for other comorbid conditions. After muscle injury or atrophy, satellite cells are activated as myoblasts, which proliferate, differentiate, and fuse with myofibers to aid in repairing and rebuilding skeletal muscle. While decreased myoblast differentiation with ethanol (EtOH) is well-documented, we have also observed fewer myoblasts with in vitro EtOH after the proliferative phase of myogenesis. The extent of this decrease and whether this is due primarily to increased cell death, decreased cell division, or a combination thereof remains unanswered. Therefore, the objective of this study is to quantify effects of EtOH on myoblast cell division and death during the proliferative phase. C2C12 myoblasts were proliferated in the presence or absence of 50 mM EtOH for 24, 48, and 72 hrs. Nuclei were stained with DAPI to quantify differences in cell count at each time point. Lactate dehydrogenase (LDH) activity was measured in cell culture supernatant at 48 and 72 hrs and normalized to cell count to assess overall cytotoxicity. T-tests were used to determine differences between conditions at each time point. There were no significant differences in cell counts between cells grown with 0 and 50 mM EtOH at 24 or 48 hrs. At 72 hrs, EtOH significantly decreased cell count (p=0.03). There were no significant differences for LDH activity at 48 hrs. At 72 hrs, LDH activity was significantly lower in the 50 mM group (p=0.05). These preliminary results suggest that EtOH decreases cell count in a time-dependent manner. Cytotoxicity appeared lower with EtOH, although this is likely due to lower intracellular LDH activity given our previously observed adverse impacts of EtOH on myoblast glycolytic function. Regardless, the present data do not support increased cytotoxicity with 50 mM EtOH. Next steps will be to assess alterations in myoblast apoptosis and cell division with EtOH. Future work based on the results of these experiments will examine possible nutraceutical supplements and exercise-like stimulation as interventions to rescue alcohol-mediated effects on myoblast proliferation, which may improve subsequent differentiation and therefore regenerative capacity. This work was supported by Texas Tech University (TTU) startup funds and a TTU College of Arts & Sciences Undergraduate Research Experiences grant (DL). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Toxicity of two heavy rare earth elements to freshwater mussels Dreissena polymorpha

Rare earth elements (REE) are essential components of many electronic devices that could end-up in solid waste disposal sites and inadvertently released in the environment. The purpose of this study was to examine the toxicity of two heavy REEs, erbium (Er) and lutetium (Lu), in freshwater mussels Dreissena polymorpha. Mussels were exposed to 14 days to increasing concentration (10, 50, 250, and 1250 µg/L) of either Er and Lu at 15 °C and analyzed for gene expression in catalase (CAT), superoxide dismutase (SOD), metallothionein (MT), cytochrome c oxidase (CO1), and cyclin D for cell cycle. In addition, lipid peroxidation (LPO), DNA damage (DNAd), and arachidonate cyclooxygenase were also determined. The data revealed that mussels accumulated Er and Lu similarly and both REEs induced changes in mitochondrial COI activity. Er increased cell division, MT, and LPO, while Lu increased DNAd and decreased cell division. Tissue levels of Er were related to changes in MT (r = 0.7), LPO (r = 0.42), CO1 (r = 0.69), and CycD (r = 0.31). Lu tissue levels were related to changes in CO1 (r = 0.73), CycD (r = − 0.61), CAT (r = 0.31), DNAd (r = 0.43), and SOD (r = 0.34). Although the lethal threshold was similar between Er and Lu, the threshold response for LPO revealed that Er produced toxicity at concentrations 25 times lower than Lu suggesting that Er was more harmful than Lu in mussels. In conclusions, the data supports that the toxicity pattern differed between Er and Lu although they are accumulated in the same fashion.

Illicium verum anticancer activity against MDA-MB-231 cell line.

To evaluate the anticancer activity of methanolic extract of Illicium verum against triple-negative breast cancer MDA-MB-231 cell line. A cell culture experimental study was carried out at Pharmacology department of Bahria University Medical and Dental College (January to June 2021) in collaboration with Aga Khan University, Karachi, Pakistan. Cell viability and proliferation assays were used to quantify dead and alive cells by utilizing a tetrazolium assay and an enzyme immunosorbent plate reader was used to calculate their absorbance. For the apoptosis initiation assay, these cells were dyed with a fluorescent stain and observed for fluorescence and apoptosis. During cell viability testing, various I. verum methanolic extract doses (0.125, 0.25, 0.5, 1, 3, 6, 12, and 25µg/ml) were employed to treat MDA-MB-231 cells, while the IC50 dose of 2.8µg/ml was used for both the cell proliferation and apoptosis initiation assays. In the cell viability assay, all I. verum methanolic extract doses exhibited a substantial decrease in the viability of MDA-MB-231 cells (less than 0.01 p-value). In cell proliferation assay and apoptosis initiation, the IC50 dose of 2.8µg/ml of I. verum methanolic extract also exhibited a substantial decrease in cell division (less than 0.01 p-value) and the initiation of apoptosis in MDA-MB-231 cells. Illicium verum methanolic extract have strong anticancer activity against triple-negative breast cancer MDA-MB-231 cell line through cytotoxicity, proliferation reduction, and apoptosis initiation mechanisms.

Illicium verum anticancer activity against MDA-MB-231 cell line

Objective: To evaluate the anticancer activity of methanolic extract of Illicium verum against triple-negative breast cancer MDA-MB-231 cell line.
 Methods: A cell culture experimental study was carried out at Pharmacology department of Bahria University Medical and Dental College (January to June 2021) in collaboration with Aga Khan University, Karachi, Pakistan. Cell viability and proliferation assays were used to quantify dead and alive cells by utilizing a tetrazolium assay and an enzyme immunosorbent plate reader was used to calculate their absorbance. For the apoptosis initiation assay, these cells were dyed with a fluorescent stain and observed for fluorescence and apoptosis. During cell viability testing, various I. verum methanolic extract doses (0.125, 0.25, 0.5, 1, 3, 6, 12, and 25µg/ml) were employed to treat MDA-MB-231 cells, while the IC50 dose of 2.8µg/ml was used for both the cell proliferation and apoptosis initiation assays.
 Results: In the cell viability assay, all I. verum methanolic extract doses exhibited a substantial decrease in the viability of MDA-MB-231 cells (less than 0.01 p-value). In cell proliferation assay and apoptosis initiation, the IC50 dose of 2.8µg/ml of I. verum methanolic extract also exhibited a substantial decrease in cell division (less than 0.01 p-value) and the initiation of apoptosis in MDA-MB-231 cells.
 Conclusion: Illicium verum methanolic extract have strong anticancer activity against triple-negative breast cancer MDA-MB-231 cell line through cytotoxicity, proliferation reduction, and apoptosis initiation mechanisms.
 doi: https://doi.org/10.12669/pjms.40.1.7860
 How to cite this: Pahore AK, Khan S, Karim N. Illicium verum anticancer activity against MDA-MB-231 cell line. Pak J Med Sci. 2024;40(1):---------. doi: https://doi.org/10.12669/pjms.40.1.7860
 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Phosphate starvation regulates cellulose synthesis to modify root growth.

In the model plant Arabidopsis (Arabidopsis thaliana), the absence of the essential macro-nutrient phosphate reduces primary root growth through decreased cell division and elongation, requiring alterations to the polysaccharide-rich cell wall surrounding the cells. Despite its importance, the regulation of cell wall synthesis in response to low phosphate levels is not well understood. In this study, we show that plants increase cellulose synthesis in roots under limiting phosphate conditions, which leads to changes in the thickness and structure of the cell wall. These changes contribute to the reduced growth of primary roots in low-phosphate conditions. Furthermore, we found that the cellulose synthase complex (CSC) activity at the plasma membrane increases during phosphate deficiency. Moreover, we show that this increase in the activity of the CSC is likely due to alterations in the phosphorylation status of cellulose synthases in low-phosphate conditions. Specifically, phosphorylation of CELLULOSE SYNTHASE 1 (CESA1) at the S688 site decreases in low-phosphate conditions. Phosphomimic versions of CESA1 with an S688E mutation showed significantly reduced cellulose induction and primary root length changes in low-phosphate conditions. Protein structure modeling suggests that the phosphorylation status of S688 in CESA1 could play a role in stabilizing and activating the CSC. This mechanistic understanding of root growth regulation under limiting phosphate conditions provides potential strategies for changing root responses to soil phosphate content.

Lung Organotypic Slices Enable Rapid Quantification of Acute Radiotherapy Induced Toxicity.

To rapidly assess healthy tissue toxicities induced by new anti-cancer therapies (i.e., radiation alone or in combination with drugs), there is a critical need for relevant and easy-to-use models. Consistent with the ethical desire to reduce the use of animals in medical research, we propose to monitor lung toxicity using an ex vivo model. Briefly, freshly prepared organotypic lung slices from mice were irradiated, with or without being previously exposed to chemotherapy, and treatment toxicity was evaluated by analysis of cell division and viability of the slices. When exposed to different doses of radiation, this ex vivo model showed a dose-dependent decrease in cell division and viability. Interestingly, monitoring cell division was sensitive enough to detect a sparing effect induced by FLASH radiotherapy as well as the effect of combined treatment. Altogether, the organotypic lung slices can be used as a screening platform to rapidly determine in a quantitative manner the level of lung toxicity induced by different treatments alone or in combination with chemotherapy while drastically reducing the number of animals. Translated to human lung samples, this ex vivo assay could serve as an innovative method to investigate patients' sensitivity to radiation and drugs.

Cytokinin Promotes Jasmonic Acid Accumulation in the Control of Maize Leaf Growth.

Plant organ growth results from the combined activity of cell division and cell expansion. The co-ordination of these two processes depends on the interplay between multiple hormones that determine the final organ size. Using the semidominant Hairy Sheath Frayed1 (Hsf1) maize mutant that hypersignals the perception of cytokinin (CK), we show that CK can reduce leaf size and growth rate by decreasing cell division. Linked to CK hypersignaling, the Hsf1 mutant has an increased jasmonic acid (JA) content, a hormone that can inhibit cell division. The treatment of wild-type seedlings with exogenous JA reduces maize leaf size and growth rate, while JA-deficient maize mutants have increased leaf size and growth rate. Expression analysis revealed the increased transcript accumulation of several JA pathway genes in the Hsf1 leaf growth zone. A transient treatment of growing wild-type maize shoots with exogenous CK also induced the expression of JA biosynthetic genes, although this effect was blocked by the co-treatment with cycloheximide. Together, our results suggest that CK can promote JA accumulation, possibly through the increased expression of specific JA pathway genes.

B2 O3 nanoparticles alleviate salt stress in maize leaf growth zones by enhancing photosynthesis and maintaining mineral and redox status.

Salt stress induces significant loss in crop yield worldwide. Although the growth-stimulating effects of micronutrient nanoparticles (NPs) application under salinity have been studied, the molecular and biochemical mechanisms underlying these effects are poorly understood. The large size of maize leaf growth zones provides an ideal model system to sample and investigate the molecular and physiological bases of growth at subzonal resolution. Using kinematic analysis, our study indicated that salinity at 150 mM inhibited maize leaf growth by decreasing cell division and expansion in the meristem and elongation zones. Consistently, salinity downregulated cell cycle gene expression (wee1, mcm4, and cyclin-B2-4). B2 O3 NP (BNP) mitigated the stress-induced growth inhibition by reducing the decrease in cell division and expansion. BNP also enhanced the photosynthesis-related parameters. Simultaneously, chlorophyll, phosphoenolpyruvate carboxylase and ribulose-1,5-bisphosphate carboxylase/oxygenase were stimulated in the mature zone. Concomitant with growth stimulation by BNP, mineral homeostasis, particularly for B and Ca, was monitored. BNP reduced oxidative stress (e.g., lessened H2 O2 generation along the leaf zones and reduced lipid peroxidation in the mature zone) induced by salinity. This resulted from better maintenance of the redox status, that is, increased the glutathione-ascorbate cycle in the meristem and elongation zones, and flavonoids and tocopherol levels in the mature zone. Our study has important implications for assessing the salinity stress impact mitigated by BNP on maize growth, providing a basis to improve the resilience of crop species under salinity stress conditions.

Anti-cancer ability of chitosan nanoparticles loaded plant essential oil evaluated against A549 human lung cancer cells through invitro approaches

Based on the recent research, the natural polysaccharide rich biopolymer of chitosan is an important carrier molecule for drug loading. In addition, the plant essential oils were another important material that frequently used to treat various infectious diseases. In addition, the chitosan loaded essential oils were heightened recent years due to the excellent biomedical properties. In this regard, the current study result was concentrated with encapsulation of plant essential oils into the chitosan nanoparticles for inhibit against A549 human lung cancer cells. In result, the unique and uniform size morphology of chitosan was clearly shown in scanning electron microscope (SEM) and transmission electron microscope (TEM). Further, the IC50 dose of the chitosan loaded essential oils at 1000 µg/mL concentration against A549 lung cancer cells was confirmed using cytotoxicity assay and this concentration was very effective than chitosan and essential oils alone. At 1000 µg/mL concentration, the high proliferation efficiency with unclear morphological evidence of A549 lung cancer cells was shown in phase contrast microscope. In addition, the AO/EB stain result was indicated more death cells with belbing formation of the treated cells were observed. At 1000 µg/mL of IC50 concentration of chitosan loaded essential oils was damaged the A549 lung cancer cells with high necrotic cells, chromatin condensation, and decreased cell division. Therefore, all the invitro experiments results were clearly stated that the chitosan loaded essential oils as more efficient alternative option to inhibit the cancer cells.

Temperature changes in the root ecosystem affect plant functionality

Climate change is increasing the frequency of extreme heat events that aggravate its negative impact on plant development and agricultural yield. Most experiments designed to study plant adaption to heat stress apply homogeneous high temperatures to both shoot and root. However, this treatment does not mimic the conditions in natural fields, where roots grow in a dark environment with a descending temperature gradient. Excessively high temperatures severely decrease cell division in the root meristem, compromising root growth, while increasing the division of quiescent center cells, likely in an attempt to maintain the stem cell niche under such harsh conditions. Here, we engineered the TGRooZ, a device that generates a temperature gradient for in vitro or greenhouse growth assays. The root systems of plants exposed to high shoot temperatures but cultivated in the TGRooZ grow efficiently and maintain their functionality to sustain proper shoot growth and development. Furthermore, gene expression and rhizosphere or root microbiome composition are significantly less affected in TGRooZ-grown roots than in high-temperature-grown roots, correlating with higher root functionality. Our data indicate that use of the TGRooZ in heat-stress studies can improve our knowledge of plant response to high temperatures, demonstrating its applicability from laboratory studies to the field.

Elevated pentose phosphate pathway flux supports appendage regeneration

A fundamental step in regeneration is rapid growth to replace lost tissue. Cells must generate sufficient lipids, nucleotides, and proteins to fuel rapid cell division. To define metabolic pathways underlying regenerative growth, we undertake a multimodal investigation of metabolic reprogramming in Xenopus tropicalis appendage regeneration. Regenerating tissues have increased glucose uptake; however, inhibition of glycolysis does not decrease regeneration. Instead, glucose is funneled to the pentose phosphate pathway (PPP), which is essential for full tail regeneration. Liquid chromatography-mass spectrometry (LC-MS) metabolite profiling reveals increased nucleotide and nicotinamide intermediates required for cell division. Using single-cell RNA sequencing (scRNA-seq), we find that highly proliferative cells have increased transcription of PPP enzymes and not glycolytic enzymes. Further, PPP inhibition results in decreased cell division specifically in regenerating tissue. Our results inform a model wherein regenerating tissues direct glucose toward the PPP, yielding nucleotide precursors to drive regenerative cell proliferation.

F-Box Protein 11 Suppresses Cell Proliferation and Aerobic Glycolysis in Glioblastomas by Mediating the Ubiquitin Degradation of Cdc25A.

Glioblastoma is a malignant CNS tumor with an extremely poor prognosis. F-box protein 11 (FBXO11) has E3 ubiquitin ligase activity and participates in the pathogenesis of multiple tumors but the role and mechanism of FBXO11 activity in glioblastoma remain unknown. In this study, FBXO11 was first observed to be downregulated in glioblastoma tissues and cell lines. 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di- phenytetrazoliumromide (MTT) and colony formation assays and enzyme linked immunosorbent assay (ELISA) demonstrated that overexpression of FBXO11 suppressed proliferation and aerobic glycolysis and induced cell cycle arrest in U251-MG and A172 cells. FBXO1 decreased cell division cycle 25 A (Cdc25A) expression through ubiquitin degradation in a coprecipitation assay. A Western blot assay validated FBXO11 suppression of PKM2 dephosphorylation and c-Myc-mediated aerobic glycolysis via reduction of Cdc25A. In addition, a rescue experiment revealed that FBXO11 suppressed proliferation and aerobic glycolysis, both of which were reversed by overexpression of Cdc25A. FBXO11 overexpression also inhibited tumorigenesis via suppressing Cdc25A expression in vivo. These findings indicate that FBXO11 suppresses cell proliferation and aerobic glycolysis in glioblastomas by mediating the ubiquitin degradation of Cdc25A thereby providing insight into mechanisms of glioblastoma tumorigenesis and identifying a new potential therapeutic strategy.

METTL3-mediated m6A RNA methylation regulates dorsal lingual epithelium homeostasis

The dorsal lingual epithelium, which is composed of taste buds and keratinocytes differentiated from K14+ basal cells, discriminates taste compounds and maintains the epithelial barrier. N6-methyladenosine (m6A) is the most abundant mRNA modification in eukaryotic cells. How METTL3-mediated m6A modification regulates K14+ basal cell fate during dorsal lingual epithelium formation and regeneration remains unclear. Here we show knockout of Mettl3 in K14+ cells reduced the taste buds and enhanced keratinocytes. Deletion of Mettl3 led to increased basal cell proliferation and decreased cell division in taste buds. Conditional Mettl3 knock-in mice showed little impact on taste buds or keratinization, but displayed increased proliferation of cells around taste buds in a protective manner during post-irradiation recovery. Mechanically, we revealed that the most frequent m6A modifications were enriched in Hippo and Wnt signaling, and specific peaks were observed near the stop codons of Lats1 and FZD7. Our study elucidates that METTL3 is essential for taste bud formation and could promote the quantity recovery of taste bud after radiation.

Cytokinins is involved in regulation of tomato pericarp thickness and fruit size.

Although cytokinins (CKs) regulate fruit development, no direct genetic evidence supports the role of endogenous CKs in pericarp growth or development or fruit size. Here, we report that the reduction in levels of endogenous active CKs via overexpression of the CK-inactivating enzyme gene AtCKX2 specifically in fruit tissues resulted in reduced pericarp thickness and smaller fruit size compared with wild-type control fruits. Pericarp thickness and single fruit weight in transgenic plants were significantly reduced. Analysis of paraffin sections showed that the reduced pericarp thickness was due largely to a decreased number of cells, and thus decreased cell division. Transcriptome profiling showed that the expression of cell division- and expansion-related genes was reduced in AtCKX2-overexpressing fruits. In addition, the expression of auxin-signaling and gibberellin-biosynthetic genes was repressed, whereas that of gibberellin-inactivating genes was enhanced, in AtCKX2-overexpressing fruits. These results demonstrate that endogenous CKs regulate pericarp cell division and subsequently fruit size. They also suggest that CKs interact with auxin and gibberellins in regulating tomato pericarp thickness and fruit size.

The effect of paclitaxel on apoptosis, autophagy and mitotic catastrophe in AGS cells

Paclitaxel is an anti-microtubule agent that has been shown to induce cell death in gastric cancer. However, the detailed mechanism of action is unclear. In this study, we reveal that the paclitaxel-induced cell death mechanism involves mitotic catastrophe, autophagy and apoptosis in AGS cells. Paclitaxel induced intrinsic apoptosis by activating caspase-3, caspase-9 and PARP. In addition, the significant increase in autophagy marker LC3B-II, together with Atg5, class III PI3K and Beclin-1, and the down-regulation of p62 following paclitaxel treatment verified that paclitaxel induced autophagy. Further experiments showed that paclitaxel caused mitotic catastrophe, cell cycle arrest of the accumulated multinucleated giant cells at the G2/M phase and induction of cell death in 24 h. Within 48 h, the arrested multinucleated cells escaped mitosis by decreasing cell division regulatory proteins and triggered cell death. Cells treated with paclitaxel for 48 h were grown in fresh medium for 24 h and checked for CDC2, CDC25C and lamin B1 protein expressions. These proteins had decreased significantly, indicating that the remaining cells became senescent. In conclusion, it is suggested that paclitaxel-induced mitotic catastrophe is an integral part of the cell death mechanism, in addition to apoptosis and autophagy, in AGS cells.

Effect of buscopan, a compound that alleviates cramps, on the developing nervous system of the chick embryo.

Buscopan is used to treat stomach cramps including those resulting from irritable bowel syndrome, bladder cramps, and pain related to menstruation. Its pregnancy category is determined as C. It has been shown in experimental animal studies that the drug has a negative effect on the embryo, but sufficient and well-controlled studies have not been conducted in humans. The aim of this study is to investigate effects of buscopan on the development of the neural tube (NT) in chick embryos. Sixty specific pathogen-free (SPF) fertilized eggs were used. SPF eggs were placed in an incubator and divided into six groups at 28 hr of incubation. Five different doses (low to high) of buscopan were injected sub-blastodermally.At the end of 48 hr, the embryos were evaluated morphologicallyand histopathologically. The argyrophilic nucleolar-organizing region (AgNOR) method was used in this study to determine the proliferation activity of cells in NT development in chick embryos. AgNOR number and total AgNOR area/nuclear area (TAA/NA) were detected for each embryo. Depending on the dose, the embryo's crown-rump length and somite number decreased (p < .05). Significant differences were detected among all groups for mean AgNOR number (p < .05) and TAA/NA ratio (p < .05). Considering the average count of AgNOR cells and TAA/NA ratio, it was found that there was a decrease in cell division depending on the dose. It was determined that buscopan treatment on chick embryos adversely affected early nervous system and NT development.

Transcriptomic analyze of the less branches of Brassica napus L. suitable for mechanized harvesting

Rapeseed (Brassica napus L.) is one of the main oil crops in the world. Its multi branching characteristics cause great difficulties and losses to mechanical harvesting. Less branched plant type is a favorable feature for promoting mechanical harvesting. In this paper, a natural mutant rape of less branches with NY12 (Ningyou 12) as background was obtained, which was named sfz (shao fen zhi, meaning less branches in Chinese). The mutant showed a significant decrease in branching and a significant increase in the lowest branch height, which are beneficial to harvest. Transcriptomic analysis of shoot tip tissue showed that the expression of gens related to strigolactone is up-regulated, which promotes its inhibitory effect on plant branching, and the expression of genes related to cell division cycle and cytoplasmic division were all down regulated. It is speculated that the decrease of cell division may also result in the decrease of branching. The research provides a basis for the formation of branching and promoted the development of mechanized harvesting.