Cell Cycle-related Genes Research Articles

Integrated transcriptome and DNA methylome analysis reveal the biological base of increased resistance to gray leaf spot and growth inhibition in interspecific grafted tomato scions.

Grafting is widely used as an important agronomic approach to deal with environmental stresses. However, the molecular mechanism of grafted tomato scions in response to biotic stress and growth regulation has yet to be fully understood. This study investigated the resistance and growth performance of tomato scions grafted onto various rootstocks. A scion from a gray leaf spot-susceptible tomato cultivar was grafted onto tomato, eggplant, and pepper rootstocks, creating three grafting combinations: one self-grafting of tomato/tomato (TT), and two interspecific graftings, namely tomato/eggplant (TE) and tomato/pepper (TP). The study utilized transcriptome and DNA methylome analyses to explore the regulatory mechanisms behind the resistance and growth traits in the interspecific graftings. Results indicated that interspecific grafting significantly enhanced resistance to gray leaf spot and improved fruit quality, though fruit yield was decreased compared to self-grafting. Transcriptome analysis demonstrated that, compared to self-grafting, interspecific graftings triggered stronger wounding response and endogenous immune pathways, while restricting genes related to cell cycle pathways, especially in the TP grafting. Methylome data revealed that the TP grafting had more hypermethylated regions at CHG (H = A, C, or T) and CHH sites than the TT grafting. Furthermore, the TP grafting exhibited increased methylation levels in cell cycle related genes, such as DNA primase and ligase, while several genes related to defense kinases showed decreased methylation levels. Notably, several kinase transcripts were also confirmed among the rootstock-specific mobile transcripts. The study concludes that interspecific grafting alters gene methylation patterns, thereby activating defense responses and inhibiting the cell cycle in tomato scions. This mechanism is crucial in enhancing resistance to gray leaf spot and reducing growth in grafted tomato scions. These findings offer new insights into the genetic and epigenetic contributions to agronomic trait improvements through interspecific grafting.

TRPS1 modulates chromatin accessibility to regulate estrogen receptor alpha (ER) binding and ER target gene expression in luminal breast cancer cells.

Common genetic variants in the repressive GATA-family transcription factor (TF) TRPS1 locus are associated with breast cancer risk, and luminal breast cancer cell lines are particularly sensitive to TRPS1 knockout. We introduced an inducible degron tag into the native TRPS1 locus within a luminal breast cancer cell line to identify the direct targets of TRPS1 and determine how TRPS1 mechanistically regulates gene expression. We acutely deplete over 80 percent of TRPS1 from chromatin within 30 minutes of inducing degradation. We find that TRPS1 regulates transcription of hundreds of genes, including those related to estrogen signaling. TRPS1 directly regulates chromatin structure, which causes estrogen receptor alpha (ER) to redistribute in the genome. ER redistribution leads to both repression and activation of dozens of ER target genes. Downstream from these primary effects, TRPS1 depletion represses cell cycle-related gene sets and reduces cell doubling rate. Finally, we show that high TRPS1 activity, calculated using a gene expression signature defined by primary TRPS1-regulated genes, is associated with worse breast cancer patient prognosis. Taken together, these data suggest a model in which TRPS1 modulates the genomic distribution of ER, both activating and repressing transcription of genes related to cancer cell fitness.

The molecular circadian rhythms regulating the cell cycle.

The circadian clock controls the expression of a large proportion of protein-coding genes in mammals and can modulate a wide range of physiological processes. Recent studies have demonstrated that disruption or dysregulation of the circadian clock is involved in the development and progression of several diseases, including cancer. The cell cycle is considered to be the fundamental process related to cancer. Accumulating evidence suggests that the circadian clock can control the expression of a large number of genes related to the cell cycle. This article reviews the mechanism of cell cycle-related genes whose chromatin regulatory elements are rhythmically occupied by core circadian clock transcription factors, while their RNAs are rhythmically expressed. This article further reviews the identified oscillatory cell cycle-related genes in higher organisms such as baboons and humans. The potential functions of these identified genes in regulating cell cycle progression are also discussed. Understanding how the molecular clock controls the expression of cell cycle genes will be beneficial for combating and treating cancer.

Morphological Changes of 3T3 Cells under Simulated Microgravity.

Cells are sensitive to changes in gravity, especially the cytoskeletal structures that determine cell morphology. The aim of this study was to assess the effects of simulated microgravity (SMG) on 3T3 cell morphology, as demonstrated by a characterization of the morphology of cells and nuclei, alterations of microfilaments and microtubules, and changes in cycle progression. 3T3 cells underwent induced SMG for 72 h with Gravite®, while the control group was under 1G. Fluorescent staining was applied to estimate the morphology of cells and nuclei and the cytoskeleton distribution of 3T3 cells. Cell cycle progression was assessed by using the cell cycle app of the Cytell microscope, and Western blot was conducted to determine the expression of the major structural proteins and main cell cycle regulators. The results show that SMG led to decreased nuclear intensity, nuclear area, and nuclear shape and increased cell diameter in 3T3 cells. The 3T3 cells in the SMG group appeared to have a flat form and diminished microvillus formation, while cells in the control group displayed an apical shape and abundant microvilli. The 3T3 cells under SMG exhibited microtubule distribution surrounding the nucleus, compared to the perinuclear accumulation in control cells. Irregular forms of the contractile ring and polar spindle were observed in 3T3 cells under SMG. The changes in cytoskeleton structure were caused by alterations in the expression of major cytoskeletal proteins, including β-actin and α-tubulin 3. Moreover, SMG induced 3T3 cells into the arrest phase by reducing main cell cycle related genes, which also affected the formation of cytoskeleton structures such as microfilaments and microtubules. These results reveal that SMG generated morphological changes in 3T3 cells by remodeling the cytoskeleton structure and downregulating major structural proteins and cell cycle regulators.

Deficiency of copper responsive gene stmn4 induces retinal developmental defects.

As part of the central nervous system (CNS), the retina senses light and also conducts and processes visual impulses. The damaged development of the retina not only causes visual damage, but also leads to epilepsy, dementia and other brain diseases. Recently, we have reported that copper (Cu) overload induces retinal developmental defects and down-regulates microtubule (MT) genes during zebrafish embryogenesis, but whether the down-regulation of microtubule genes mediates Cu stress induced retinal developmental defects is still unknown. In this study, we found that microtubule gene stmn4 exhibited obviously reduced expression in the retina of Cu overload embryos. Furthermore, stmn4 deficiency (stmn4-/-) resulted in retinal defects similar to those seen in Cu overload embryos, while overexpression of stmn4 effectively rescued retinal defects and cell apoptosis occurred in the Cu overload embryos and larvae. Meanwhile, stmn4 deficient embryos and larvae exhibited reduced mature retinal cells, the down-regulated expression of microtubules and cell cycle-related genes, and the mitotic cell cycle arrests of the retinal cells, which subsequently tended to apoptosis independent on p53. The results of this study demonstrate that Cu stress might lead to retinal developmental defects via down-regulating expression of microtubule gene stmn4, and stmn4 deficiency leads to impaired cell cycle and the accumulation of retinal progenitor cells (RPCs) and their subsequent apoptosis. The study provides a certain referee for copper overload in regulating the retinal development in fish.

Decreased NSD2 impairs stromal cell proliferation in human endometrium via reprogramming H3K36me2.

The proliferation of the endometrium is regulated by histone methylation. This study shows that decreased NSD2 impairs proliferative-phase endometrial stromal cell proliferation in patients with recurrent implantation failure via epigenetic reprogramming of H3K36me2 methylation on the promoter region of MCM7. Recurrent implantation failure (RIF) is a formidable challenge in assisted reproductive technology because of its unclear molecular mechanism. Impaired human endometrial stromal cell (HESC) proliferation disrupts the rhythm of the menstrual cycle, resulting in devastating disorders between the embryo and the endometrium. The molecular function of histone methylation enzymes in modulating HESC proliferation remains largely uncharacterized. Herein, we found that the levels of histone methyltransferase nuclear receptor binding SET domain protein 2 (NSD2) and the dimethylation of lysine 36 on histone H3 are decreased significantly in the proliferative-phase endometrium of patients with RIF. Knockdown of NSD2 in an HESC cell line markedly impaired cell proliferation and globally reduced H3K36me2 binding to chromatin, leading to altered expression of many genes. Transcriptomic analyses revealed that cell cycle-related gene sets were downregulated in the endometrium of patients with RIF and in NSD2‑knockdown HESCs. Furthermore, RNA-sequencing and CUT&Tag sequencing analysis suggested that NSD2 knockdown reduced the binding of H3K36me2 to the promoter region of cell cycle marker gene MCM7 (encoding minichromosome maintenance complex component 7) and downregulated its expression. The interaction of H3K36me2 with the MCM7 promoter was verified using chromatin immunoprecipitation-quantitative real-time PCR. Our results demonstrated a unifying epigenome-scale mechanism by which decreased NSD2 impairs endometrial stromal cell proliferation in the proliferative-phase endometrium of patients with RIF.

Downregulation of PTPRT elevates the expression of survivin and promotes the proliferation, migration, and invasion of lung adenocarcinoma

BackgroundReceptor-type tyrosine-protein phosphatase T (PTPRT) is a transmembrane protein that is involved in cell adhesion. We previously found that PTPRT was downregulated in multiple cancer types and the mutation of PTPRT was associated with cancer early metastasis. However, the impacts of PTPRT downregulation on tumour proliferation, invasion, and clinical interventions such as immune checkpoint inhibitor (ICI) therapies remained largely unknown.MethodsGene expression data of non-small cell lung cancer (NSCLC) samples from The Cancer Genome Atlas database were downloaded and used to detect the differential expressed genes between PTPRT-high and PTPRT-low subgroups. Knockdown and overexpress of PTPRT in lung cancer cell lines were performed to explore the function of PTPRT in vitro. Western blot and qRT-PCR were used to evaluate the expression of cell cycle-related genes. CCK-8 assays, wound-healing migration assay, transwell assay, and colony formation assay were performed to determine the functional impacts of PTPRT on cell proliferation, migration, and invasion. KM-plotter was used to explore the significance of selected genes on patient prognosis.ResultsPTPRT was found to be downregulated in tumours and lung cancer cell lines compared to normal samples. Cell cycle-related genes (BIRC5, OIP5, and CDCA3, etc.) were specifically upregulated in PTPRT-low lung adenocarcinoma (LUAD). Modulation of PTPRT expression in LUAD cell lines affected the expression of BIRC5 (survivin) significantly, as well as the proliferation, migration, and invasion of tumour cells. In addition, low PTPRT expression level was correlated with worse prognosis of lung cancer and several other cancer types. Furthermore, PTPRT downregulation was associated with elevated tumour mutation burden and tumour neoantigen burden in lung cancer, indicating the potential influence on tumour immunogenicity.ConclusionOur findings uncovered the essential roles of PTPRT in the regulation of proliferation, migration, and invasion of LUAD, and highlighted the clinical significance of PTPRT downregulation in lung cancer.

Establishment and Validation of Novel Prognostic Subtypes in Hepatocellular Carcinoma Based on Bile Acid Metabolism Gene Signatures Using Bulk and Single-Cell RNA-Seq Data.

Hepatocellular carcinoma (HCC) is a highly detrimental cancer type and has limited therapeutic options, posing significant threats to human health. The development of HCC has been associated with a disorder in bile acid (BA) metabolism. In this study, we employed an integrative approach, combining various datasets and omics analyses, to comprehensively characterize the tumor microenvironment in HCC based on genes related to BA metabolism. Our analysis resulted in the classification of HCC samples into four subtypes (C1, C2a, C2b, and C3). Notably, subtype C2a, characterized by the highest bile acid metabolism score (BAMS), exhibited the highest survival probability. This subtype also demonstrated increased immune cell infiltration, lower cell cycle scores, reduced AFP levels, and a lower risk of metastasis compared to subtypes C1 and C3. Subtype C1 displayed poorer survival probability and elevated cell cycle scores. Importantly, the identified subtypes based on BAMS showed potential relevance to the gene expression of drug targets in currently approved drugs and those under clinical research. Genes encoding VEGFR (FLT4 and KDR) and MET were elevated in C2, while genes such as TGFBR1, TGFB1, ADORA3, SRC, BRAF, RET, FLT3, KIT, PDGFRA, and PDGFRB were elevated in C1. Additionally, FGFR2 and FGFR3, along with immune target genes including PDCD1 and CTLA4, were higher in C3. This suggests that subtypes C1, C2, and C3 might represent distinct potential candidates for TGFB1 inhibitors, VEGFR inhibitors, and immune checkpoint blockade treatments, respectively. Significantly, both bulk and single-cell transcriptome analyses unveiled a negative correlation between BA metabolism and cell cycle-related pathways. In vitro experiments further confirmed that the treatment of HCC cell lines with BA receptor agonist ursodeoxycholic acid led to the downregulation of the expression of cell cycle-related genes. Our findings suggest a plausible involvement of BA metabolism in liver carcinogenesis, potentially mediated through the regulation of tumor cell cycles and the immune microenvironment. This preliminary understanding lays the groundwork for future investigations to validate and elucidate the specific mechanisms underlying this potential association. Furthermore, this study provides a novel foundation for future precise molecular typing and the design of systemic clinical trials for HCC therapy.

The inhibitory and transcriptional effects of the epigenetic repurposed drugs hydralazine and valproate in lymphoma cells.

Lymphoma is a disease that affects countless lives each year. In order to combat this disease, researchers have been exploring the potential of DNMTi and HDACi drugs. These drugs target the cellular processes that contribute to lymphomagenesis and treatment resistance. Our research evaluated the effectiveness of a combination of two such drugs, hydralazine (DNMTi) and valproate (HDACi), in B-cell and T-cell lymphoma cell lines. Here we show that the combination of hydralazine and valproate decreased the viability of cells over time, leading to the arrest of cell-cycle and apoptosis in both B and T-cells. This combination of drugs proved to be synergistic, with each drug showing significant growth inhibition individually. Microarray analyses of HuT 78 and Raji cells showed that the combination of hydralazine and valproate resulted in the up-regulation of 562 and 850 genes, respectively, while down-regulating 152 and 650 genes. Several proapoptotic and cell cycle-related genes were found to be up-regulated. Notably, three and five of the ten most up-regulated genes in HuT 78 and Raji cells, respectively, were related to immune function. In summary, our study suggests that the combination of hydralazine and valproate is an effective treatment option for both B- and T-lymphomas. These findings are highly encouraging, and we urge further clinical evaluation to validate our research and potentially improve lymphoma treatment.

Emerging role of HDAC11 in skeletal muscle biology.

HDAC11 is an epigenetic repressor of gene transcription, acting through its deacetylase activity to remove functional acetyl groups from the lysine residues of histones at genomic loci. It has been implicated in the regulation of different immune responses, metabolic activities, as well as cell cycle progression. Recent studies have also shed lights on the impact of HDAC11 on myogenic differentiation and muscle development, indicating that HDAC11 is important for histone deacetylation at the promoters to inhibit transcription of cell cycle related genes, thereby permitting myogenic activation at the onset of myoblast differentiation. Interestingly, the upstream networks of HDAC11 target genes are mainly associated with cell cycle regulators and the acetylation of histones at the HDAC11 target promoters appears to be residue specific. As such, selective inhibition, or activation of HDAC11 presents a potential therapeutic approach for targeting distinct epigenetic pathways in clinical applications.

Ginsenoside Rg5 induces NSCLC cell apoptosis and autophagy through PI3K/Akt/mTOR signaling pathway.

Ginsenoside Rg5 (Rg5) is a minor ginsenoside of ginseng and has a strong anti-tumor potential. This study focused on deciphering the function of Rg5 in non-small cell lung cancer (NSCLC) and investigating its related mechanism. After treating human NSCLC cell lines (H1650 and A549) and bronchial epithelial cells (BEAS-2B) with increasing concentration of Rg5, cell viability was examined using methyl thiazolyl tetrazolium (MTT) assay. NSCLC cell proliferation and apoptosis were evaluated by colony formation assay and flow cytometry, respectively. The levels of proteins associated with cell cycle progression, cell apoptosis, and autophagy as well as the key markers in the PI3K/Akt/mTOR pathway were measured using western blot. A xenograft nude mouse model was established to explore the function of Rg5 in vivo. NSCLC cell viability was dose- and time-dependently suppressed after Rg5 treatment. Rg5 restrained NSCLC cell proliferation by inducing G2/M phase arrest via regulation of cell cycle-related genes including p21, cyclin B1, and Cdc2. Additionally, Rg5 promoted caspase-dependent apoptosis in NSCLC cells by regulating the intrinsic mitochondrial signaling pathway. Rg5 induced autophagy via the regulation of autophagy-related proteins. The in vivo experiments revealed the inhibitory impact of Rg5 on xenograft growth. Rg5 also inactivated the PI3K/Akt/mTOR signaling pathway in NSCLC cells and mouse tumors. Rg5 induced autophagy and caspase-dependent apoptosis in NSCLC cells by inhibiting the PI3K/Akt/mTOR signaling pathway, suggesting that Rg5 might become a promising and novel anti-tumor agent for the clinical treatment of NSCLC patients.

PPIH as a poor prognostic factor increases cell proliferation and m6A RNA methylation in hepatocellular carcinoma.

RNA-binding proteins (RBPs) play a crucial role in the biological processes of liver hepatocellular carcinoma (LIHC). Peptidyl-prolyl cis-trans isomerase H (PPIH), an RBP, possesses prolyl isomerase activity and functions as a protein chaperone. The relationship between PPIH and LIHC has not yet been fully elucidated. This study elucidated potential mechanisms through which PPIH affects the prognosis of LIHC. Bioinformatics analysis and in vitro experiments revealed that PPIH expression was higher in LIHC tissues than in normal tissues. PPIH was identified as an independent prognostic factor, with high PPIH expression being associated with worse prognoses. Moreover, PPIH increased the m6A RNA methylation level and promoted cell proliferation by modulating DNA replication and the expression of cell cycle-related genes in LIHC cells. Bioinformatics analysis also revealed that PPIH expression increased immune cell infiltration and the expression of immune checkpoint proteins. Collectively, these findings indicate that PPIH might promote LIHC progression by enhancing the m6A RNA methylation level, increasing cell proliferation, and altering the tumor immune microenvironment. Our study demonstrates that PPIH, as a poor prognostic factor, may lead to LIHC malignancy through multiple pathways. Further in-depth research on this topic is warranted.

Elevated RACGAP1 Expression Enhances Malignant Potential in Lung Adenocarcinoma and Serves as a Prognostic Factor.

Background: While RACGAP1 is identified as a potential oncogene, its specific role in lung adenocarcinoma (LUAD) remains unclear. Methods: First, we conducted a comprehensive analysis of the role of RACGAP1 across 33 types of cancer. Subsequently, we investigated the expression levels of RACGAP1 and its impact on prognosis using data from The Cancer Genome Atlas (TCGA) database. We utilized single-cell sequencing data to explore the tumor-related processes of RACGAP1 in LUAD and validated our findings through experimental verification. Employing a consensus clustering (CC) approach, we subdivided LUAD patients into two subtypes based on RACGAP1 cell cycle-related genes (RrCCGs). These subtypes exhibited significant differences in tumor characteristics, lymph node metastasis, and recurrence. Furthermore, we evaluated the prognostic influence of RrCCGs using univariate Cox regression and least absolute shrinkage and selection operator regression models (LASSO), successfully establishing a prognostic model. Results: RACGAP1 is frequently overexpressed in various tumors and can impact the prognosis of patients with LUAD. Additionally, experimental evidence has demonstrated that low expression of RACGAP1 favors tumor cell apoptosis and restoration of the cell cycle, while high expression promotes invasion and metastasis. Through CC analysis of RrCCGs, patients were classified into two groups, with survival analysis revealing distinct prognoses and stages between the two groups. Furthermore, Cox and LASSO regression successfully constructed a prognostic model with robust predictive capability.

Nitrate stimulates adventitious rooting by increasing auxin content and regulating auxin- and root development-related genes expression in apple

Adventitious root (AR) formation is critical for cutting survival and nutrient absorption re-establishment. This complex genetic trait involves the interplay of nitrogen, endogenous hormones, and several key genes. In this study, we treated GL-3 apple (Malus domestica) in vitro shoots with nitrate and ammonium to determine their impact on AR formation, hormonal content, and gene expression patterns. Nitrate treatment significantly promotes adventitious rooting by increasing cell division, differentiation, and AR primordia formation compared to ammonium treatment. Elevated indole-3-acetic acid (IAA), reduced abscisic acid, and zeatin riboside concentrations were consistently observed with nitrate, likely crucial for promoting ARs over ammonium. Furthermore, Malus domestica auxin resistance1 (MdAUX1) expression was induced, increasing IAA levels. MdIAA23 was upregulated. Further results indicate that the higher expression levels of Malusdomestica WUSCHEL-relatedHomeobox gene 11 (MdWOX11), Malus domestica lateral organ boundariesdomaingene 16 (MdLBD16), and MdLBD29, and increased cell cycle-related gene expressions, contribute to auxin-stimulated adventitious rooting under nitrate conditions. In conclusion, this study establishes that auxin content and associated genes related to root development and cell cycle contribute to superior ARs in response to nitrate.

Potential effects of parietin on apoptosis and cell cycle related genes in SH-SY5Y neuroblastoma cells

Background: Ingredients obtained from natural products have been used in cancer treatments for years. High diversity and non-toxicity compared to chemotherapeutic agents are the main reasons for their preference. Lichens having potential for treatment of cancer consist of fungus and 1-2 species of algae. Under the name of lichen substances, many of them have also been synthesized as specific substances. The secondary metabolites in lichens are generally insoluble in water, and have many biological activities such as antiviral, antitumor, antibacterial, and antioxidant; they store in the fungal cell or on the surface of the hyphae and can only be extracted with organic solvents.
 Parietin extracted from lichen species such as xanthoria parietina is an anthraquinone pigment and a secondary metabolite. 
 In our study, the effects of parietin on cytotoxicity, gene expression, migration, invasion, and colony formation in neuroblastoma cells treated with parietin were investigated. The SH-SY5Y neuroblastoma (NB), which is not treated with parietin, was administered as a control group.
 Methods: The IC50 value of the parietin was determined using XTT assay. The total RNA extractions were performed from the cells using the Tri-Reagent kit. The expressions of BCL-XL, BCL-2, MMP2, MMP9, P21, CYCLIN D1, CASAPASE-3, CASAPASE-9, BAX, P53, PUMA, and NOXA genes were investigated by Lightcycler 480 (Roche) using SYBR Green dye. Migration analysis of the control and the dose group cells were performed in accordance with the Wound-healing assay protocol. Invasion activities were determined using the “Invasion Chamber” (BD Biosciences) protocol. The colony assay was treated with crystal violet and the cells were observed under the light microscope.
 Results: The IC50 value of the parietin used for 48-hour treatment on the cells was determined as 35 µM. It was found that the expression levels of BCL-XL, BCL-2, MMP2, MMP9, P21, and CYCLIN D1 mRNA were downregulated, and it was also shown the expression levels of CASAPASE-3, CASAPASE-9, BAX, P53, PUMA, and NOXA to be upregulated. It was determined that parietin suppressed both cell invasion and migration, and colony formation in the neuroblastoma cells. 
 Conclusions: Thus, it can be possible parietin to be used as an alternative, complementary, and supportive agent together with the other drugs in the treatment of neuroblastoma. However, more comprehensive studies supporting these significant effects of parietin will increase its potential in the application.

Sphingomyelin Metabolism Modifies Luminal A Breast Cancer Cell Line under a High Dose of Vitamin C.

The role of sphingomyelin metabolism and vitamin C in cancer has been widely described with conflicting results ranging from a total absence of effect to possible preventive and/or protective effects. The aim of this study was to establish the possible involvement of sphingomyelin metabolism in the changes induced by vitamin C in breast cancer cells. The MCF7 cell line reproducing luminal A breast cancer and the MDA-MB-231 cell line reproducing triple-negative breast cancer were used. Cell phenotype was tested by estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2 expression, and proliferation index percentage. Sphingomyelin was localized by an EGFP-NT-Lys fluorescent probe. Sphingomyelin metabolism was analyzed by RT-PCR, Western blotting and UFLC-MS/MS. The results showed that a high dose of vitamin C produced reduced cell viability, modulated cell cycle related genes, and changed the cell phenotype with estrogen receptor downregulation in MCF7 cell. In these cells, the catabolism of sphingomyelin was promoted with a large increase in ceramide content. No changes in viability and molecular expression were observed in MB231 cells. In conclusion, a high dose of vitamin C induces changes in the luminal A cell line involving sphingomyelin metabolism.

Road dust exposure and human corneal damage in a plateau high geological background provincial capital city: Spatial distribution, sources, bioaccessibility, and cytotoxicity of dust heavy metals

Ocular surface diseases are common in the plateau city, Kunming China, the continued daily exposure to heavy metals in dust may be an important inducement. In this study, the 150 road dust samples from five functional areas in Kunming were collected. The concentrations, distribution, possible sources, and bioaccessibility of heavy metals were analyzed. The adverse effects of dust extracts on human corneal epithelial cells and the underlying mechanisms were also assessed. The concentrations (mg·kg−1) of As (19.1), Cd (2.67), Cr (90.5), Cu (123), Pb (78.4), and Zn (389) in road dust were higher than the soil background, with commercial and residential areas showing the highest pollution. Their bioaccessibility in artificial tears was As (6.59 %) > Cu (5.11 %) > Ni (1.47 %) > Cr (1.17 %) > Mn (0.84 %) > Cd (0.76 %) > Zn (0.50 %) > Pb (0.31 %). The two main sources of heavy metals included tire and mechanical abrasion (24.5 %) and traffic exhaust (21.6 %). All dust extracts induced cytotoxicity, evidenced by stronger inhibition of cell viability, higher production of ROS, and altered mRNA expression of antioxidant enzymes and cell cycle-related genes, with commercial- areas-2 (CA2)-dust extract showing the greatest oxidative damage and cell cycle arrest. Our data may provide new evidence that dust exposure in high geological background cities could trigger human cornea damage.

Abstract A025: Cytostatic effects and expression modulations in cell cycle genes by a 3rd generation alkyl-phospholipid (erufosine) in liver and lung cancer cells

Abstract Introduction: Alkyl-phospholipids (ALPs) are a family of compounds that have affinity to cell membranes and have demonstrated antineoplastic potential. Erufosine is a 3rd generation ALP that can be injected intravenously for its long (22-carbon) chain with a cis-13,14 double bond. Erufosine, like other ALPs, causes changes in the lipid rafts of the cell membrane and exerts its anticancer effects through cytotoxic and cytostatic mechanisms. In this study, intentions were to investigate erufosine mediated cytostatic effects in liver and lung cancer cells at functional and molecular levels. Materials and Methods: Liver (HepG2) and lung (H1299) cancer cell lines were exposed to various concentrations of erufosine (1.56-50µM) and resulting anti-proliferative effects were monitored via MTT dye reduction assay. Cytostatic effects of erufosine on the two cancer cell lines were investigated via propidium iodide-based DNA staining and FACS analysis. A real time PCR based panel was used to decipher the impact of erufosine exposure on 84 cell cycle related genes in the two cancer cell lines. Fold changes were identified via the Livak method while untreated cells were used as controls. Results: Erufosine induced the anti-proliferative effects in both cancer cell lines, however, lung cancer cells were more sensitive (IC50: 6.25µM) as compared to liver cancer cells (IC50: 33µM). The compound induced a comparable cell cycle arrest in S phase in the cancer cell lines as reflected by more accumulation of the cells in this particular phase. Exposure with erufosine (IC50/48 hours) de-regulated the cell cycle related genes in both cancer cell lines. Again, the lung cancer cells were more responsive in comparison to liver cancer cells as reflected by a substantial de-regulation (≥2fold) of 35/84 (42%) and 13/84 (15%) genes, respectively. Conclusion: The findings of this study confirmed erufosine mediated anti-proliferative and cytostatic effects in the liver and lung cancer cells. Furthermore, the compound induced substantial alterations in cell cycle related genes in the two cancer cell lines. Present findings foster further research to investigate the antineoplastic effects induced by erufosine in liver and lung cancer cells to support its clinical utilization. Citation Format: Asim Pervaiz, Marriyam Nasim, Nazakat Shafiq, Martin R. Berger. Cytostatic effects and expression modulations in cell cycle genes by a 3rd generation alkyl-phospholipid (erufosine) in liver and lung cancer cells [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr A025.

#43 : Expression of miRNA-21-3p in Polycystic Ovary Syndrome and its Related Functions

Background and Aims: PCOS is an endocrine-related disease related to abnormal folliculogenesis and is a leading cause of infertility worldwide. Inhibition of GCs proliferation and increased GCs apoptosis have been identified as the major factors in aberrant follicle maturation. Recently, the roles of miRNAs were identified in polycystic ovary syndrome (PCOS). For instance, miR-21-3p was identified as an important miRNA regulating autophagy of BGCs. Besides, studies showed that AMSC-EXOs can rescue the polycystic phenotype and metabolic dysfunction in PCOS ovaries by transferring miR-21-5p to the livers of rats with PCOS, finally improve reproduction. However, there is no research clarified the association between miRNA-21-3p and GCs function to date. Method: In the present study, letrozole was used to establish the PCOS rat model. Separate the ovary and then miRNA-21-3p expression will be analyzed by RT-PCR. Primary rat ovarian GCs were isolated and incubated and transfected with mimic or inhibitor of miRNA-21-3p, CCK8 kit was used to detect cell viability, PR-PCR was used to detect cell proliferation and apoptosis related gene expression. Finally, flowcytometry was used to test apoptosis rate of Gcs. Results: The expression of miR-21-3p in the ovaries of PCOS rats was significantly increased compared with that in control rats. Primary rat ovarian GCs were isolated and incubated successfully, and then CCK-8 experiment showed that GCs viability was significantly decreased when miR-21-3p was overexpressed. Additionally, the miR-21-3p mimic significantly decreased the expression of PCNA, Bcl-2, cell cycle-related genes (CDK2, CCNE1) and increased the expression of Bax and caspase3 in primary rat ovarian GCs. By contrast, transfected primary rat ovarian GCs using the miR-21-3p inhibitor significantly upregulated the expression of PCNA, Bcl-2, cell cycle-regulated genes (CDK2, CCNE1) and reduced the expression of Bax and caspase3. Finally, flow cytometry analysis demonstrated that overexpression of miR-21-3p significantly increased the apoptosis rate of GCs. By contrast, the suppression of miR-21-3p resulted in a significant decrease in the apoptosis rate of GCs. Conclusion: In PCOS rat model, miRNA-21-3p was proved significantly increased compared with that in control rats. Which is participant in the development of PCOS by regulating the function of granular cells.

Transcriptome-based network analysis of cell cycle-related genes in response to blue and red light in maize

Abstract In maize, blue and red light are key environmental factors regulating cell-cycle progression. We used transcriptomics to investigate and compare differential gene expression under the four light conditions: red light, blue light, red converted to blue and blue converted to red. A total of 23 differentially expressed genes were identified. The gene–gene interaction analysis indicated a significant interaction between four unidentified genes, 100191551, pco143873, 100284747 and pco060490, and cell-cycle-related genes. Using multiple sequence alignment analysis and protein structure comparisons, we show here that these four unidentified genes were characterized as ALP1-like, ALP1, cyclin P1-1 and AEBP2, respectively. By constructing a protein–protein interaction network, we inferred that 100191551 and pco143873 are potentially regulated to avoid DNA damage by abiotic stress response factors in the cell cycle. The gene 100284747 regulates the cell cycle in response to phosphate starvation signalling. The gene pco060490 potentially negatively regulates the cell cycle through the mediation of Histone H3 and CYCD6 in response to red light. In conclusion, the cell-cycle-related genes are sensitive to blue and red light, and four novel functional genes may be involved in the cell cycle.