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Cell cycle checkpoints detect DNA errors, eventually arresting the cell cycle to promote DNA repair. Failure of such cell cycle arrest causes aberrant cell proliferation, promoting the pathogenesis of multiple diseases, including cancer. Endoplasmic reticulum (ER) stress transducers activate the unfolded protein response, which not only deals with unfolded proteins in ER lumen but also orchestrates diverse physiological phenomena such as cell differentiation and lipid metabolism. Among ER stress transducers, cyclic AMP‐responsive element‐binding protein 3‐like protein 1 (CREB3L1) [also known as old astrocyte specifically induced substance (OASIS)] is an ER‐resident transmembrane transcription factor. This molecule is cleaved by regulated intramembrane proteolysis, followed by activation as a transcription factor. OASIS is preferentially expressed in specific cells, including astrocytes and osteoblasts, to regulate their differentiation. In accordance with its name, OASIS was originally identified as being upregulated in long‐term‐cultured astrocytes undergoing cell cycle arrest because of replicative stress. In the context of cell cycle regulation, previously unknown physiological roles of OASIS have been discovered. OASIS is activated as a transcription factor in response to DNA damage to induce p21‐mediated cell cycle arrest. Although p21 is directly induced by the master regulator of the cell cycle, p53, no crosstalk occurs between p21 induction by OASIS or p53. Here, we summarize previously unknown cell cycle regulation by ER‐resident transcription factor OASIS, particularly focusing on commonalities and differences in cell cycle arrest between OASIS and p53. This review also mentions tumorigenesis caused by OASIS dysfunctions, and OASIS's potential as a tumor suppressor and therapeutic target. [ABSTRACT FROM AUTHOR]

Understanding the dynamics of RNA targeting to membraneless organelles is essential to disentangle their functions. Here, we investigate how P-bodies (PBs) evolve during cell-cycle progression in HEK293 cells. PB purification across the cell cycle uncovers widespread changes in their RNA content, partly uncoupled from cell-cycle-dependent changes in RNA expression. Single-molecule fluorescence in situ hybridization (FISH) shows various mRNA localization patterns in PBs peaking in G1, S, or G2, with examples illustrating the timely capture of mRNAs in PBs when their encoded protein becomes dispensable. Rather than directly reflecting absence of translation, cyclic mRNA localization in PBs can be controlled by RBPs, such as HuR in G2, and by RNA features. Indeed, while PB mRNAs are AU rich at all cell-cycle phases, they are specifically longer in G1, possibly related to post-mitotic PB reassembly. Altogether, our study supports a model where PBs are more than a default location for excess untranslated mRNAs. [Display omitted] • Cyclic mRNA accumulation in PBs is partly uncoupled from cytoplasmic abundance • smFISH highlights various patterns of cyclic PB mRNA accumulation, notably in G1 • HuR-mRNA interactions reduce mRNA PB localization in G2 • PB mRNAs are particularly long in G1, while AU rich all along the cell cycle Safieddine et al. purify P-bodies across the cell cycle, revealing that their RNA content is dynamic and partly uncoupled from that of the surrounding cytoplasm. RNA imaging highlights various patterns of cyclic mRNA localization. Extrinsic and intrinsic factors such as HuR and RNA length contribute to cyclic mRNA localization. [ABSTRACT FROM AUTHOR]

Stimulation of pancreatic beta cell regeneration could be a therapeutic lead to treat diabetes. Unlike humans, the zebrafish can efficiently regenerate beta cells, notably from ductal pancreatic progenitors. To gain insight into the molecular pathways involved in this process, we established the transcriptomic profile of the ductal cells after beta cell ablation in the adult zebrafish. These data highlighted the protein phosphatase calcineurin (CaN) as a new potential modulator of beta cell regeneration. We showed that CaN overexpression abolished the regenerative response, leading to glycemia dysregulation. On the opposite, CaN inhibition increased ductal cell proliferation and subsequent beta cell regeneration. Interestingly, the enhanced proliferation of the progenitors was paradoxically coupled with their exhaustion. This suggests that the proliferating progenitors are next entering in differentiation. CaN appears as a guardian which prevents an excessive progenitor proliferation to preserve the pool of progenitors. Altogether, our findings reveal CaN as a key player in the balance between proliferation and differentiation to enable a proper beta cell regeneration. [ABSTRACT FROM AUTHOR]

AbstractSix substituted α-cyano-indolylchalcones have been prepared and their structures were verified by various spectral analysis tools. Compared with the standard drug 5-Fluorouracil) 5-FU(, the anticancer activity against prostate cancer (PC3) and breast cancer cell line (MCF7) was determined using the cytotoxic MTT assay. Also, the cytotoxic effect against normal melanocytes (HFB4) was studied to detect the selectivity of the compounds. Among the series, compound 3e was the most active and selective one toward MCF7 (IC50= 0.18 µmole/mL, SI= 7.6). In silico studies were performed to demonstrate the inhibitory effect of compound 3e on EGFRK, CDK2, and MDM2 domains. Different molecular techniques were performed to know the efficacy of the novel 3e on apoptotic death of breast carcinoma cells. [ABSTRACT FROM AUTHOR]

Simple Summary: Around 50% of all human cancers are treated with radiotherapy. The effectiveness of radiotherapy is driven through causing DNA damage within the cancer cells; however, the cells respond by activating repair mechanisms that can lead to resistance to treatment. A promising strategy is to target one of these defence mechanisms, called the cell cycle checkpoint, using specific drugs/inhibitors that can be used in combination with radiotherapy. Here, we review evidence of investigations into inhibitors of two important proteins (Chk1 and Wee1) and how these can be used to increase the effectiveness of radiotherapy in cancer treatment. Radiotherapy is one of the main cancer treatments being used for ~50% of all cancer patients. Conventional radiotherapy typically utilises X-rays (photons); however, there is increasing use of particle beam therapy (PBT), such as protons and carbon ions. This is because PBT elicits significant benefits through more precise dose delivery to the cancer than X-rays, but also due to the increases in linear energy transfer (LET) that lead to more enhanced biological effectiveness. Despite the radiotherapy type, the introduction of DNA damage ultimately drives the therapeutic response through stimulating cancer cell death. To combat this, cells harbour cell cycle checkpoints that enables time for efficient DNA damage repair. Interestingly, cancer cells frequently have mutations in key genes such as TP53 and ATM that drive the G1/S checkpoint, whereas the G2/M checkpoint driven through ATR, Chk1 and Wee1 remains intact. Therefore, targeting the G2/M checkpoint through specific inhibitors is considered an important strategy for enhancing the efficacy of radiotherapy. In this review, we focus on inhibitors of Chk1 and Wee1 kinases and present the current biological evidence supporting their utility as radiosensitisers with different radiotherapy modalities, as well as clinical trials that have and are investigating their potential for cancer patient benefit. [ABSTRACT FROM AUTHOR]

Abstract Background Chronic myeloid leukemia (CML) is a common hematological malignancy, and tyrosine kinase inhibitors (TKIs) represent the primary therapeutic approach for CML. Activation of metabolism signaling pathway has been connected with BCR::ABL1-independent TKIs resistance in CML cells. However, the specific mechanism by which metabolism signaling mediates this drug resistance remains unclear. Here, we identified one relationship between glutamine synthetase (GS) and BCR::ABL1-independent Imatinib resistance in CML cells. Methods GS and PXN-AS1 in bone marrow samples of CML patients with Imatinib resistance (IR) were screened and detected by whole transcriptome sequencing. GS expression was upregulated using LVs and blocked using shRNAs respectively, then GS expression, Gln content, and cell cycle progression were respectively tested. The CML IR mice model were established by tail vein injection, prognosis of CML IR mice model were evaluated by Kaplan–Meier analysis, the ratio of spleen/body weight, HE staining, and IHC. PXN-AS1 level was blocked using shRNAs, and the effects of PXN-AS1 on CML IR cells in vitro and in vivo were tested the same as GS. Several RNA-RNA tools were used to predict the potential target microRNAs binding to both GS and PXN-AS1. RNA mimics and RNA inhibitors were used to explore the mechanism through which PXN-AS1 regulates miR-635 or miR-635 regulates GS. Results GS was highly expressed in the bone marrow samples of CML patients with Imatinib resistance. In addition, the lncRNA PXN-AS1 was found to mediate GS expression and disorder cell cycle in CML IR cells via mTOR signaling pathway. PXN-AS1 regulated GS expression by binding to miR-635. Additionally, knockdown of PXN-AS1 attenuated BCR::ABL1-independent Imatinib resistance in CML cells via PXN-AS1/miR-635/GS/Gln/mTOR signaling pathway. Conclusions Thus, PXN-AS1 promotes GS-mediated BCR::ABL1-independent Imatinib resistance in CML cells via cell cycle signaling pathway. Graphic Abstract

Abstract Background RNA modifications of transfer RNAs (tRNAs) are critical for tRNA function. Growing evidence has revealed that tRNA modifications are related to various disease processes, including malignant tumors. However, the biological functions of methyltransferase-like 1 (METTL1)-regulated m7G tRNA modifications in breast cancer (BC) remain largely obscure. Methods The biological role of METTL1 in BC progression were examined by cellular loss- and gain-of-function tests and xenograft models both in vitro and in vivo. To investigate the change of m7G tRNA modification and mRNA translation efficiency in BC, m7G-methylated tRNA immunoprecipitation sequencing (m7G tRNA MeRIP-seq), Ribosome profiling sequencing (Ribo-seq), and polysome-associated mRNA sequencing were performed. Rescue assays were conducted to decipher the underlying molecular mechanisms. Results The tRNA m7G methyltransferase complex components METTL1 and WD repeat domain 4 (WDR4) were down-regulated in BC tissues at both the mRNA and protein levels. Functionally, METTL1 inhibited BC cell proliferation, and cell cycle progression, relying on its enzymatic activity. Mechanistically, METTL1 increased m7G levels of 19 tRNAs to modulate the translation of growth arrest and DNA damage 45 alpha (GADD45A) and retinoblastoma protein 1 (RB1) in a codon-dependent manner associated with m7G. Furthermore, in vivo experiments showed that overexpression of METTL1 enhanced the anti-tumor effectiveness of abemaciclib, a cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitor. Conclusion Our study uncovered the crucial tumor-suppressive role of METTL1-mediated tRNA m7G modification in BC by promoting the translation of GADD45A and RB1 mRNAs, selectively blocking the G2/M phase of the cell cycle. These findings also provided a promising strategy for improving the therapeutic benefits of CDK4/6 inhibitors in the treatment of BC patients.

Abstract Artesunate (ART), an effective antimalarial semisynthetic derivative of artemisinin, exhibits antitumour properties, but the mechanism(s) involved remain elusive. In this study, we investigated the antitumour effects of ART on human oesophageal squamous cell carcinoma (ESCC) cell lines. Treatment of ESCC cell lines with ART resulted in the production of excessive reactive oxygen species (ROS) that induced DNA damage, reduced cell proliferation and inhibited clonogenicity via G1-S cell cycle arrest and/or apoptosis in vitro. The administration of ART to nude mice with ESCC cell xenografts inhibited tumour formation in vivo. However, the cytotoxicity of ART strongly differed among the ESCC cell lines tested. Transcriptomic profiling revealed that although the expression of large numbers of genes in ESCC cell lines was affected by ART treatment, these genes could be functionally clustered into pathways involved in regulating cell cycle progression, DNA metabolism and apoptosis. We revealed that p53 and Cdk4/6-p16-Rb cell cycle checkpoint controls were critical determinants required for mediating ART cytotoxicity in ESCC cell lines. Specifically, KYSE30 cells with p53 Mut /p16 Mut were the most sensitive to ART, KYSE150 and KYSE180 cells with p53 Mut /p16 Nor exhibited intermediate responses to ART, and Eca109 cells with p53 Nor /p16 Nor exhibited the most resistance to ATR. Consistently, perturbation of p53 expression using RNA interference (RNAi) and/or Cdk4/6 activity using the inhibitor palbociclib altered ART cytotoxicity in KYSE30 cells. Given that the p53 and Cdk4/6-cyclin D1-p16-Rb genes are commonly mutated in ESCC, our results potentially shed new light on neoadjuvant chemotherapy strategies for ESCC.

Abstract Breast cancer patients often have a poor prognosis largely due to lack of effective targeted therapy. It is now well established that monosaccharide enhances growth retardation and chemotherapy sensitivity in tumor cells. However, Pectinose whether has capability to restrict the proliferation of tumor cells remain unclear. Here, we report that Pectinose induced cytotoxicity is modulated by autophagy and p38 MAPK signaling pathway in breast cancer cell lines. The proliferation of cells was dramatically inhibited by Pectinose exposure in a dose-dependent manner, which was relevant to cell cycle arrest, as demonstrated by G2/M cell cycle restriction and ectopic expression of Cyclin A, Cyclin B, p21and p27. Mechanistically, we further identified that Pectinose is positively associated with autophagy and the activation of the p38 MAPK signaling in breast cancer. In contrast, 3-Ma or SB203580, the inhibitor of autophagy or p38 MAPK, reversed the efficacy of Pectinose suppressing on breast cancer cell lines proliferation and cell cycle process. Additionally, Pectinose in vivo treatment could significantly inhibit xenograft growth of breast cancer cells. Taken together, our findings were the first to reveal that Pectinose triggered cell cycle arrest by inducing autophagy through the activation of p38 MAPK signaling pathway in breast cancer cells,especially in luminal A and triple-negative breast cancer.

Abstract Background Mutations in isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2), are present in most gliomas. IDH1 mutation is an important prognostic marker in glioma. However, its regulatory mechanism in glioma remains incompletely understood. Results miR-182-5p expression was increased within IDH1-mutant glioma specimens according to TCGA, CGGA, and online dataset GSE119740, as well as collected clinical samples. (R)-2-hydroxyglutarate ((R)-2HG) treatment up-regulated the expression of miR-182-5p, enhanced glioma cell proliferation, and suppressed apoptosis; miR-182-5p inhibition partially eliminated the oncogenic effects of R-2HG upon glioma cells. By direct binding to Cyclin Dependent Kinase Inhibitor 2 C (CDKN2C) 3’UTR, miR-182-5p inhibited CDKN2C expression. Regarding cellular functions, CDKN2C knockdown promoted R-2HG-treated glioma cell viability, suppressed apoptosis, and relieved cell cycle arrest. Furthermore, CDKN2C knockdown partially attenuated the effects of miR-182-5p inhibition on cell phenotypes. Moreover, CDKN2C knockdown exerted opposite effects on cell cycle check point and apoptosis markers to those of miR-182-5p inhibition; also, CDKN2C knockdown partially attenuated the functions of miR-182-5p inhibition in cell cycle check point and apoptosis markers. The engineered CS-NPs (antagomir-182-5p) effectively encapsulated and delivered antagomir-182-5p, enhancing anti-tumor efficacy in vivo, indicating the therapeutic potential of CS-NPs(antagomir-182-5p) in targeting the miR-182-5p/CDKN2C axis against R-2HG-driven oncogenesis in mice models. Conclusions These insights highlight the potential of CS-NPs(antagomir-182-5p) to target the miR-182-5p/CDKN2C axis, offering a promising therapeutic avenue against R-2HG’s oncogenic influence to glioma.

Abstract Breast cancer patients often have a poor prognosis largely due to lack of effective targeted therapy. It is now well established that monosaccharide enhances growth retardation and chemotherapy sensitivity in tumor cells. We investigated whether d-arabinose has capability to restrict the proliferation of tumor cells and its mechanism. Here, we report that d-arabinose induced cytotoxicity is modulated by autophagy and p38 MAPK signaling pathway in breast cancer cell lines. The proliferation of cells was evaluated by CCK-8 and Colony formation assay. The distribution of cells in cell cycle phases was analyzed by flow cytometry. Cell cycle, autophagy and MAPK signaling related proteins were detected by western blotting. Mouse xenograft model was used to evaluate the efficacy of d-arabinose in vivo. The proliferation of cells was dramatically inhibited by d-arabinose exposure in a dose-dependent manner, which was relevant to cell cycle arrest, as demonstrated by G2/M cell cycle restriction and ectopic expression of cell cycle related proteins. Mechanistically, we further identified that d-arabinose is positively associated with autophagy and the activation of the p38 MAPK signaling in breast cancer. In contrast, 3-Ma or SB203580, the inhibitor of autophagy or p38 MAPK, reversed the efficacy of d-arabinose. Additionally, d-arabinose in vivo treatment could significantly inhibit xenograft growth of breast cancer cells. Our findings were the first to reveal that d-arabinose triggered cell cycle arrest by inducing autophagy through the activation of p38 MAPK signaling pathway in breast cancer cells.

Objective To explore the intrinsic relationship between circadian clock and cell cycle in osteoarthritis(OA) chondrocytes, especially the regulation of cell cycle-related genes by the clock gene Bmal1. Methods The chondroid ATDC5 cells induced by insulin-transfering-selenium(ITS) were divided into control group, OA group and LV-Bmal1 group. The cell viability of each group was detected by CCK8 method. The expression of Bmal1, Per1, Wee1, Cdk1, Ccnb1 and Mmp13 mRNA in each group was detected by RT-qPCR. The expression of BMAL1, PER1, WEE1, CDK1, CCNB1 and MMP13 protein in each group was detected by Western blot. The effects of Bmal1 on different stages of cell cycle and apoptosis was analyzed by flow cytometry. The regulation of Bmal1 on Per1, Wee1, Cdk1, Ccnb1 and Mmp13 and their roles in OA were analyzed. Results Compared with the normal group, the cell viability of the OA group was increased, the relative mRNA expression of Bmal1 and Wee1 in the OA group decreased, and the relative mRNA expression of Per1, Cdk1, Ccnb1 and Mmp13 increased significantly. The cell viability of LV-Bmal1 group decreased, the relative expression of Bmal1 and Wee1 mRNA increased, and the relative expression of Per1, Cdk1, Ccnb1 and Mmp13 mRNA decreased(P＜0.05). Correlation analysis showed that Bmal1 was positively correlated with Wee1 and they were negatively correlated with Per1, Cdk1, Ccnb1 or Mmp13. The results of Western blot showed that protein expression in different groups were consistent with the trend of PCR. The results of cell cycle and apoptosis showed that compared with the normal group, the S phase and G2/M phase of the OA group were shortened, the proportion of cells decreased significantly, and the proportion of early and late apoptosis increased. The S phase and G2/M phase of the LV-Bmal1 group were prolonged, the proportion of cells was increased, and the proportion of early and late apoptosis was decreased. Conclusions Circadian clock gene Bmal1 in inflammatory chondrocytes might regulate the expression of cell cycle-related genes.

The present study explores the function of FANCA gene, a pivotal member of the Fanconi anaemia (FA) pathway crucial for preserving genomic stability and preventing cancer, particularly in the context of gastric cancer (GC). Using immunohistochemistry, quantitative real-time PCR, and western blot analysis, we evaluate FANCA mRNA and protein expressions in GC cell lines. The relationship between FANCA expression and clinicopathological characteristics is also explored. Various assays, including CCK8, colony formation, wound healing, and Transwell assays, are used to assess functional changes in cells associated with FANCA. Flow cytometry is utilized to evaluate alterations in the cell cycle resulted from FANCA knockdown and overexpression. Our findings show elevated FANCA expression in GC cell lines, with levels correlated with pathologic stage and lymphatic metastasis. FANCA knockdown impedes cell proliferation, migration, and invasion and induces G1/S phase cell cycle arrest. Conversely, FANCA overexpression stimulates cell proliferation, migration, and invasion. In vivo xenograft experiments confirm the promotional role of FANCA in GC tumor progression. Moreover, FANCA overexpression is associated with the activation of cell cycle. Collectively, our results suggest that FANCA drives malignant cell behaviors in GC through the cell cycle pathway, highlighting its potential as a therapeutic target for the treatment of GC.

Abstract The cell cycle is a crucial biological process that is involved in cell growth, development, and reproduction. It can be divided into G1, S, G2, and M phases, and each period is closely regulated to ensure the production of two similar daughter cells with the same genetic material. However, many obstacles influence the cell cycle, including the R-loop that is formed throughout this process. R-loop is a triple-stranded structure, composed of an RNA: DNA hybrid and a single DNA strand, which is ubiquitous in organisms from bacteria to mammals. The existence of the R-loop has important significance for the regulation of various physiological processes. However, aberrant accumulation of R-loop due to its limited resolving ability will be detrimental for cells. For example, DNA damage and genomic instability, caused by the R-loop, can activate checkpoints in the cell cycle, which in turn induce cell cycle arrest and cell death. At present, a growing number of factors have been proven to prevent or eliminate the accumulation of R-loop thereby avoiding DNA damage and mutations. Therefore, we need to gain detailed insight into the R-loop resolution factors at different stages of the cell cycle. In this review, we review the current knowledge of factors that play a role in resolving the R-loop at different stages of the cell cycle, as well as how mutations of these factors lead to the onset and progression of diseases.

Abstract Double-stranded RNA-activated protein kinase R (PKR) is highly expressed in colorectal cancer (CRC). However, the role of PKR in CRC remains unclear. The aim of this study was to clarify whether C16 (a PKR inhibitor) exhibits antitumor effects and to identify its target pathway in CRC. We evaluated the effects of C16 on CRC cell lines using the MTS assay. Enrichment analysis was performed to identify the target pathway of C16. The cell cycle was analyzed using flow cytometry. Finally, we used immunohistochemistry to examine human CRC specimens. C16 suppressed the proliferation of CRC cells. Gene Ontology (GO) analysis revealed that the cell cycle-related GO category was substantially enriched in CRC cells treated with C16. C16 treatment resulted in G1 arrest and increased p21 protein and mRNA expression. Moreover, p21 expression was associated with CRC development as observed using immunohistochemical analysis of human CRC tissues. C16 upregulates p21 expression in CRC cells to regulate cell cycle and suppress tumor growth. Thus, PKR inhibitors may serve as a new treatment option for patients with CRC.

Abstract Background Cancer radiation treatments have seen substantial advancements, yet the biomolecular mechanisms underlying cancer cell radioresistance continue to elude full understanding. The effectiveness of radiation on cancer is hindered by various factors, such as oxygen concentrations within tumors, cells’ ability to repair DNA damage and metabolic changes. Moreover, the initial and radiation-induced cell cycle profiles can significantly influence radiotherapy responses as radiation sensitivity fluctuates across different cell cycle stages. Given this evidence and our prior studies establishing a correlation between cancer radiation resistance and an increased number of cytoplasmic Lipid Droplets (LDs), we investigated if LD accumulation was modulated along the cell cycle and if this correlated with differential radioresistance in lung and bladder cell lines. Results Our findings identified the S phase as the most radioresistant cell cycle phase being characterized by an increase in LDs. Analysis of the expression of perilipin genes (a family of proteins involved in the LD structure and functions) throughout the cell cycle also uncovered a unique gene cell cycle pattern. Conclusions In summary, although these results require further molecular studies about the mechanisms of radioresistance, the findings presented here are the first evidence that LD accumulation could participate in cancer cells’ ability to better survive X-Ray radiation when cells are in the S phase. LDs can represent new players in the radioresistance processes associated with cancer metabolism. This could open new therapeutic avenues in which the use of LD-interfering drugs might enhance cancer sensitivity to radiation.

Abstract Objective This study aimed to assess the functions of cell division cycle protein 45 (CDC45) in Non-small cell lung cancer (NSCLC) cancer and its effects on stemness and metastasis. Methods Firstly, differentially expressed genes related to lung cancer metastasis and stemness were screened by differential analysis and lasso regression. Then, in vitro, experiments such as colony formation assay, scratch assay, and transwell assay were conducted to evaluate the impact of CDC45 knockdown on the proliferation and migration abilities of lung cancer cells. Western blotting was used to measure the expression levels of related proteins and investigate the regulation of CDC45 on the cell cycle. Finally, in vivo model with subcutaneous injection of lung cancer cells was performed to verify the effect of CDC45 on tumor growth. Results This study identified CDC45 as a key gene potentially influencing tumor stemness and lymph node metastasis. Knockdown of CDC45 not only suppressed the proliferation and migration abilities of lung cancer cells but also caused cell cycle arrest at the G2/M phase. Further analysis revealed a negative correlation between CDC45 and cell cycle-related proteins, stemness-related markers, and tumor mutations. Mouse experiments confirmed that CDC45 knockdown inhibited tumor growth. Conclusion As a novel regulator of stemness, CDC45 plays a role in regulating lung cancer cell proliferation, migration, and cell cycle. Therefore, CDC45 may serve as a potential target for lung cancer treatment and provide a reference for further mechanistic research and therapeutic development.

Abstract Background Toxoplasma gondii is an apicomplexan intracellular obligate parasite and the etiological agent of toxoplasmosis in humans, domestic animals and wildlife, causing miscarriages and negatively impacting offspring. During its intracellular development, it relies on nutrients from the host cell, controlling several pathways and the cytoskeleton. T. gondii has been proven to control the host cell cycle, mitosis and cytokinesis, depending on the time of infection and the origin of the host cell. However, no data from parallel infection studies have been collected. Given that T. gondii can infect virtually any nucleated cell, including those of humans and animals, understanding the mechanism by which it infects or develops inside the host cell is essential for disease prevention. Therefore, we aimed here to reveal whether this modulation is dependent on a specific cell type or host cell species. Methods We used only primary cells from humans and bovines at a maximum of four passages to ensure that all cells were counted with appropriate cell cycle checkpoint control. The cell cycle progression was analysed using fluorescence-activated cell sorting (FACS)-based DNA quantification, and its regulation was followed by the quantification of cyclin B1 (mitosis checkpoint protein). The results demonstrated that all studied host cells except bovine colonic epithelial cells (BCEC) were arrested in the S-phase, and none of them were affected in cyclin B1 expression. Additionally, we used an immunofluorescence assay to track mitosis and cytokinesis in uninfected and T. gondii-infected cells. Results The results demonstrated that all studied host cell except bovine colonic epithelial cells (BCEC) were arrested in the S-phase, and none of them were affected in cyclin B1 expression. Our findings showed that the analysed cells developed chromosome segregation problems and failed to complete cytokinesis. Also, the number of centrosomes per mitotic pole was increased after infection in all cell types. Therefore, our data suggest that T. gondii modulates the host cell cycle, chromosome segregation and cytokinesis during infection or development regardless of the host cell origin or type. Graphical Abstract

Genetic mutations in BRCA1/2 and hMSH2 genes, as well as viral infections, have been implicated in colon cancer (CC) development and progression. Aim: To evaluate the molecular characteristics of cell cycle proteins (p53,bcl-2, NF1, pRb1) in colon cancer cases burdened by gene mutations (BRCA1/2, hMSH2) and DNA/RNA viruses. Methods: A molecular biological and immunological study was performed: cycle proteins NF1, p53, bcl-2, pRb1, viruses (HSV1/2, HHV6, CMV, VEB, HCV, HBV, HVP), BRCA 1/2 genes, hMSH2 gene. Results: The number of mutations in the BRCA1/2, and hMSH2 genes in blood samples from individuals with CC was 2.04%, while the frequency of changes in the hMSH2 gene was 4.17%, which is lower than the frequency of mutations in the same genes in tumor tissue samples – 7.98% (p=0.003). The occurrence of BRCA1/2 gene mutations among women showed their dependence on CC with exons of the hMSH2 gene. Viruses isolated in tumor tissue: HSV 1/2 – 86.8%, HHV6 – 25.0%, CMV – 10.3%, HCV 4.4%, HBV – 2.94%, HVP – 4, 1%, VEB – 19.1%, mixed inertia – 11.76%. Proteins p53, bcl-2, pRb1, and NF1 in intestinal tissue did not depend on the age and gender of patients. Conclusion: This study provides compelling evidence for the role of cell cycle proteins as diagnostic markers in colon cancer. The levels of p53, bcl 2, pRb1, and NF1 were significantly elevated in the Blood and tumor tissue of colon cancer patients compared to healthy controls.

Dysobinol is a new limonoid from C. macrophyllus seeds reported to have an anticancer activity. This study aimed to determine the cytotoxic activity of Dysobinol against HeLa cancer cell lines and evaluate its mechanism of action by determining the expression level of several carcinogenesis genes related to apoptosis and cell cycle. In this experimental study, the cytotoxic activity was determined using the MTS assay and gene expression by real-time reverse transcriptase PCR. The result shows that Dysobinol has an anticancer activity in a dose and time-dependent manner against HeLa cells and was categorized as toxic with IC50 values of 52.92, 52.70, and 14.96 μg/ml for 24, 48, and 72 hours, respectively. Dysobinol significantly increased the expression of Bax, Cas-8, and Cas-3 and decreased the expression of Cyc D1 at both doses (IC50 and 2x IC50) but only high doses (2x IC50) could affect Cas9 and NF-κB expressions, indicating that Dysobinol can induce apoptosis via the extrinsic pathway and inhibits the cell cycle through the Cyc D1 regulator. Dysobinol has the potential to be developed as a chemotherapy drug or an adjuvant agent for cervical cancer treatment.

Deguelin exhibits antiproliferative activity against various cancer cell types. Previous studies have reported that deguelin exhibits pro-apoptotic activity against human cancer cells. The current study aimed at further elaborating the anticancer effects of deguelin against multiple myeloma cells. Cell growth estimations were made through MTT assay. Phase contrast microscopy was used for the analysis of the viability of multiple myeloma cells. Colony formation from multiple myeloma cells was studied using a clonogenic assay. Antioxidative assays for determining levels of glutathione (GSH) and superoxide dismutase (SOD) were carried out after treating multiple myeloma cells with deguelin. The apoptosis of multiple myeloma cells was studied using AO/EB and Annexin V-FITC/PI staining methods. Multiple myeloma cell cycle analysis was performed through flow cytometry. mRNA expression levels were depicted using qRT-PCR. Migration and invasion of multiple myeloma cells were determined with the wound-healing and transwell assays, respectively. Deguelin specifically inhibited the multiple myeloma cell growth while the normal plasma cells were minimally affected. Multiple myeloma cells when treated with deguelin exhibited remarkably lower viability and colony-forming ability. Multiple myeloma cells treated with deguelin produced more SOD and had higher GSH levels. The multiple myeloma cell growth, migration, and invasion were significantly declined by in vitro administration of deguelin. In conclusion, deguelin treatment, when applied in vitro, induced apoptotic cell death and resulted in mitotic cessation at the G2/M phase through modulation of cell cycle regulatory mRNAs in multiple myeloma cells.

Abstract Background A traditional view is that stem cells (SCs) divide slowly. Meanwhile, both embryonic and pluripotent SCs display a shorter cell cycle duration (CCD) in comparison to more committed progenitors (CPs). Methods We examined the in vitro proliferation and cycling behavior of somatic adult human cells using live cell imaging of passage zero keratinocytes and single-cell RNA sequencing. Results We found two populations of keratinocytes: those with short CCD and protracted near exponential growth, and those with long CCD and terminal differentiation. Applying the ergodic principle, the comparative numbers of cycling cells in S phase in an enriched population of SCs confirmed a shorter CCD than CPs. Further, analysis of single-cell RNA sequencing of cycling adult human keratinocyte SCs and CPs indicated a shortening of both G1 and G2M phases in the SC. Conclusions Contrary to the pervasive paradigm, SCs progress through cell cycle more quickly than more differentiated dividing CPs. Thus, somatic human adult keratinocyte SCs may divide infrequently, but divide rapidly when they divide. Additionally, it was found that SC-like proliferation persisted in vitro.

Fragile X syndrome (FXS), the most prevalent heritable form of intellectual disability, is caused by the transcriptional silencing of the FMR1 gene. While neuronal contribution to FXS has been extensively studied in both animal and human-based models of FXS, the roles of astrocytes, a type of glial cells in the brain, are largely unknown. Here, we generated a human-based FXS model via differentiation of astrocytes from human-induced pluripotent stem cells (hiPSCs) and human embryonic stem cells (hESCs) and characterized their development, function, and proteomic profiles. We identified shortened cell cycle, enhanced Ca2+ signaling, impaired sterol biosynthesis, and pervasive alterations in the proteome of FXS astrocytes. Our work identified astrocytic impairments that could contribute to the pathogenesis of FXS and highlight astrocytes as a novel therapeutic target for FXS treatment.

Cell cycle regulation is largely abnormal in cancers. Molecular understanding and therapeutic targeting of the aberrant cell cycle are essential. Here, we identified that an underappreciated serine/threonine kinase, cyclin-dependent kinase--like 3 (CDKL3), crucially drives rapid cell cycle progression and cell growth in cancers. With regard to mechanism, CDKL3 localizes in the nucleus and associates with specific cyclin to directly phosphorylate retinoblastoma (Rb) for quiescence exit. In parallel, CDKL3 prevents the ubiquitin-proteasomal degradation of cyclin-dependent kinase 4 (CDK4) by direct phosphorylation on T172 to sustain G1 phase advancement. The crucial function of CDKL3 in cancers was demonstrated both in vitro and in vivo. We also designed, synthesized, and characterized a first-in-class CDKL3-specific inhibitor, HZ1. HZ1 exhibits greater potency than CDK4/6 inhibitor in pan-cancer treatment by causing cell cycle arrest and overcomes acquired resistance to CDK4/6 inhibitor. In particular, CDKL3 has significant clinical relevance in colon cancer, and the effectiveness of HZ1 was demonstrated by murine and patient-derived cancer models. Collectively, this work presents an integrated paradigm of cancer cell cycle regulation and suggests CDKL3 targeting as a feasible approach in cancer treatment. [ABSTRACT FROM AUTHOR]

In this study, we screened a chemical library to find potent anticancer compounds that are less cytotoxic to non-cancerous cells. This study revealed that pyrazole PTA-1 is a potent anticancer compound. Additionally, we sought to elucidate its mechanism of action (MOA) in triple-negative breast cancer cells. Cytotoxicity was analyzed with the differential nuclear staining assay (DNS). Additional secondary assays were performed to determine the MOA of the compound. The potential MOA of PTA-1 was assessed using whole RNA sequencing, Connectivity Map (CMap) analysis, in silico docking, confocal microscopy, and biochemical assays. PTA-1 is cytotoxic at a low micromolar range in 17 human cancer cell lines, demonstrating less cytotoxicity to non-cancerous human cells, indicating a favorable selective cytotoxicity index (SCI) for the killing of cancer cells. PTA-1 induced phosphatidylserine externalization, caspase-3/7 activation, and DNA fragmentation in triple-negative breast MDA-MB-231 cells, indicating that it induces apoptosis. Additionally, PTA-1 arrests cells in the S and G2/M phases. Furthermore, gene expression analysis revealed that PTA-1 altered the expression of 730 genes at 24 h (198 upregulated and 532 downregulated). A comparison of these gene signatures with those within CMap indicated a profile similar to that of tubulin inhibitors. Subsequent studies revealed that PTA-1 disrupts microtubule organization and inhibits tubulin polymerization. Our results suggest that PTA-1 is a potent drug with cytotoxicity to various cancer cells, induces apoptosis and cell cycle arrest, and inhibits tubulin polymerization, indicating that PTA-1 is an attractive drug for future clinical cancer treatment. [ABSTRACT FROM AUTHOR]

Understanding mechanisms underlying various physiological and pathological processes often requires accurate and fully automated analysis of dense cell populations that collectively migrate. In such multicellular systems, there is a rising interest in the relations between biophysical and cell cycle progression aspects. A seminal tool that led to a leap in real-time study of cell cycle is the fluorescent ubiquitination-based cell cycle indicator (FUCCI). Here, we introduce ConfluentFUCCI, an open-source graphical user interface-based framework that is designed, unlike previous tools, for fully automated analysis of cell cycle progression, cellular dynamics, and cellular morphology, in highly dense migrating cell collectives. We integrated into ConfluentFUCCI's pipeline state-of-the-art tools such as Cellpose, TrackMate, and Napari, some of which incorporate deep learning, and we wrap the entire tool into an isolated computational environment termed container. This provides an easy installation and workflow that is independent of any specific operation system. ConfluentFUCCI offers accurate nuclear segmentation and tracking using FUCCI tags, enabling comprehensive investigation of cell cycle progression at both the tissue and single-cell levels. We compare ConfluentFUCCI to the most recent relevant tool, showcasing its accuracy and efficiency in handling large datasets. Furthermore, we demonstrate the ability of ConfluentFUCCI to monitor cell cycle transitions, dynamics, and morphology within densely packed epithelial cell populations, enabling insights into mechanotransductive regulation of cell cycle progression. The presented tool provides a robust approach for investigating cell cycle-related phenomena in complex biological systems, offering potential applications in cancer research and other fields. [ABSTRACT FROM AUTHOR]

Antioxidant 1 copper chaperone (Atox1) may contribute to preventing DDP cochlear damage by regulating copper transport family and cell cycle proteins. A rat model of cochlear damage was developed by placing gelatin sponges treated with DDP in the cochlea. HEI-OC1 cells were treated with 133 μM DDP as a cell model. DDP-induced ototoxicity in rats was confirmed by immunofluorescence (IF) imaging. The damage of DDP to HEI-OC1 cells was assessed by using CCK-8, TUNEL, and flow cytometry. The relationship between Atox1, a member of the copper transport protein family, and the damage to in vivo / vitro models was explored by qRT-PCR, western blot, CCK-8, TUNEL, and flow cytometry. DDP had toxic and other side effects causing cochlear damage and promoted HEI-OC1 cell apoptosis and cell cycle arrest. The over-expression of Atox1 (oe-Atox1) was accomplished by transfecting lentiviral vectors into in vitro / vivo models. We found that oe-Atox1 increased the levels of Atox1, copper transporter 1 (CTR1), and SOD3 in HEI-OC1 cells and decreased the expression levels of ATPase copper transporting α (ATP7A) and ATPase copper transporting β (ATP7B). In addition, the transfection of oe-Atox1 decreased cell apoptosis rate and the number of G2/M stage cells. Similarly, the expression of myosin VI and phalloidin of cochlea cells in vivo decreased. Atox1 ameliorated DDP-induced damage to HEI-OC1 cells or rats' cochlea by regulating the levels of members of the copper transport family. [ABSTRACT FROM AUTHOR]

Abstract Background A greater emphasis has been placed on the part of cell cycle progression (CCP) in cancer in recent years. Nevertheless, the precise connection between CCP-related genes and bladder cancer (BCa) has remained elusive. This study endeavors to establish and validate a reliable risk model incorporating CCP-related factors, aiming to predict both the prognosis and immune landscape of BCa. Methods Clinical information and RNA sequencing data were collected from the GEO and TCGA databases. Univariate and multivariate Cox regression analyses were conducted to construct a risk model associated with CCP. The performance of the model was assessed using ROC and Kaplan–Meier survival analyses. Functional enrichment analysis was employed to investigate potential cellular functions and signaling pathways. The immune landscape was characterized using CIBERSORT algorithms. Integration of the risk model with various clinical variables led to the development of a nomogram. Results To build the risk model, three CCP-related genes (RAD54B, KPNA2, and TPM1) were carefully chosen. ROC and Kaplan–Meier survival analysis confirm that our model has good performance. About immunological infiltration, the high-risk group showed decreased levels of regulatory T cells and dendritic cells coupled with increased levels of activated CD4 + memory T cells, M2 macrophages, and neutrophils. Furthermore, the nomogram showed impressive predictive power for OS at 1, 3, and 5 years. Conclusion This study provides new insights into the association between the CCP-related risk model and the prognosis of BCa, as well as its impact on the immune landscape.

Abstract Background Regorafenib, a multi-targeted kinase inhibitor, has been used in the treatment of Hepatocellular carcinoma (HCC). The purpose of this study is to investigate the mechanism of Regorafenib in HCC. Methods Regorafenib’s impact on the sensitivity of HCC cells was assessed using CCK8. Differential gene expression analysis was performed by conducting mRNA sequencing after treatment with Regorafenib. The m6A methylation status of CHOP and differential expression of m6A methylation-related proteins were assessed by RIP and Western Blot. To explore the molecular mechanisms involved in the therapeutic effects of Regorafenib in HCC and the impact of METTL14 and CHOP on Regorafenib treatment, we employed shRNA/overexpression approaches to transfect METTL14 and CHOP genes, as well as conducted in vivo experiments. Results Treatment with Regorafenib led to a notable decrease in viability and proliferation of SK-Hep-1 and HCC-LM3 cells. The expression level of CHOP was upregulated after Regorafenib intervention, and CHOP underwent m6A methylation. Among the m6A methylation-related proteins, METTL14 exhibited the most significant downregulation. Mechanistic studies revealed that Regorafenib regulated the cell cycle arrest in HCC through METTL14-mediated modulation of CHOP, and the METTL14/CHOP axis affected the sensitivity of HCC to Regorafenib. In vivo, CHOP enhanced the anticancer effect of Regorafenib. Conclusion The inhibition of HCC development by Regorafenib is attributed to its modulation of m6A expression of CHOP, mediated by METTL14, and the METTL14/CHOP axis enhances the sensitivity of HCC to Regorafenib. These findings provide insights into the treatment of HCC and the issue of drug resistance to Regorafenib.

Abstract Background Research on the fatty acid metabolism related gene SLC27A2 is currently mainly focused on solid tumors, and its mechanism of action in hematological tumors has not been reported. Method This study aims to explore the pathological and immune mechanisms of the fatty acid metabolism related gene SLC27A2 in hematological tumors and verify its functional role in hematological tumors through cell experiments to improve treatment decisions and clinical outcomes of hematological tumors. Result This study identified the fatty acid metabolism related gene SLC27A2 as a common differentially expressed gene between DLBCL and AML. Immune microenvironment analysis showed that SLC27A2 was significantly positively correlated with T cell CD4 + , T cell CD8 + , endothelial cells, macrophages, and NK cells in DLBCL. In AML, there is a significant negative correlation between SLC27A2 and B cells, T cell CD8 + , and macrophages. SLC27A2 participates in the immune process of hematological tumors through T cell CD8 + and macrophages. The GESA results indicate that high expression of SLC27A2 is mainly involved in the fatty acid pathway, immune pathway, and cell cycle pathway of DLBCL. The low expression of SLC27A2 is mainly involved in the immune pathway of AML. Therefore, SLC27A2 is mainly involved in the pathological mechanisms of hematological tumors through immune pathways, and cell experiments have also confirmed that SLC27A2 is involved in the regulation of DLBCL cells. Conclusion In summary, our research results comprehensively report for the first time the mechanism of action of SLC27A2 in the immune microenvironment of DLBCL and AML, and for the first time verify the cycle and apoptotic effects of the fatty acid related gene SLC27A2 in DLBCL cells through cell experiments. Research can help improve the treatment of AML and DLBCL patients.

ZRF1 (Zuotin-related factor 1) is a versatile protein engaged in protein folding, gene regulation, cellular differentiation, DNA damage response, and immune system and cancer development regulation. This study investigates the role of ZRF1 in monocyte-to-macrophage transformation, and its effects on cell proliferation and the cell cycle.

ABSTRACT: This study aimed to probe if xylooligosaccharide (XOS) could act as an antimetabolite to impact the cell cycle and antibiotic tolerance of avian pathogenic Escherichia coli (APEC). We firstly measured the bacteriostasis of XOS against APEC O78 and its effect on the growth of APEC O78 growing on different medium. Afterwards, the effects of XOS on xylose operon activation along with the cell cycle and antibiotic tolerance of APEC O78 were analyzed. The results showed that XOS caused no inhibitory circle against APEC O78 and did not affect (P > 0.05) the growth of APEC O78 growing on LB medium. Besides, APEC O78 was unable to grow on M9 medium (carbon-free) added with XOS. However, XOS exerted a similar role as xylose in increasing (P < 0.05) the expression of certain xylose operon genes including xylose isomerase (XylA)-encoding gene (xylA) and xylose-binding periplasmic protein (XylF)-encoding gene (xylF) in APEC O78. The molecular docking simulation revealed that the major monomer components (xylobiose, xylotriose and xylotetraose) of XOS had stable binding potentials to both XylA and XylF proteins of E. coli, as supported by the low binding free energy and the formation of considerable hydrogen bonds between them. The subsequent analysis showed that XOS altered certain cell cycle-related genes expression, especially elevated (P < 0.05) nrdB expression and decreased ihfB expression to a degree. Moreover, XOS played a similar role as 2-deoxy-glucose (a glucose analogue serving as a typical antimetabolite) in lowering (P < 0.05) the number of ampicillin-tolerant APEC O78. Collectively, XOS had no direct bacteriostasis against APEC and could not be metabolized/utilized by APEC O78. However, it might become an analogue of xylose and then activate xylose transport- and metabolism-related proteins in APEC O78, thus functioning as a potential antimetabolite and exerting antimetabolic actions. This could at least partially interpret the observed roles of XOS in interfering with the cell cycle and diminishing the antibiotic tolerance of APEC O78. The above findings expand the knowledges about the functions of XOS and provide a basis for exploring novel strategies to reduce the antibiotic tolerance of APEC.

Objectives: To advance our knowledge of disease mechanisms and therapeutic options, understanding cell cycle regulation is critical. Recent research has highlighted the importance of reactive oxygen species (ROS) in cell cycle regulation. Although excessive ROS levels can lead to age-related pathologies, ROS also play an essential role in normal cellular functions. Many cell cycle regulatory proteins are affected by their redox status, but the precise mechanisms and conditions under which ROS promote or inhibit cell proliferation are not fully understood.Methods: This review presents data from the scientific literature and publicly available databases on changes in redox state during the cell cycle and their effects on key regulatory proteins.Results: We identified redox-sensitive targets within the cell cycle machinery and analysed different effects of ROS (type, concentration, duration of exposure) on cell cycle phases. For example, moderate levels of ROS can promote cell proliferation by activating signalling pathways involved in cell cycle progression, whereas excessive ROS levels can induce DNA damage and trigger cell cycle arrest or cell death.Discussion: Our findings encourage future research focused on identifying redox-sensitive targets in the cell cycle machinery, potentially leading to new treatments for diseases with dysregulated cell proliferation.

ABSTRACTIn this study, we investigated the effects of an ethanolic extract of Mangifera indica L. kernel on the viability and proliferation of human lung cancer cells. We utilized MTT and BrdU cell proliferation assays, morphological assessments, cell cycle analyses, and apoptosis assays to investigate the extract’s effects on lung cancer (A549 and NCI-H292) and normal lung (MRC-5) cells. The extract demonstrated a toxicity toward cancer cells compared to normal cells with dose-dependent anti-proliferative effect on lung cancer cells. The extract also caused differential effects on the cell cycle, inducing G0/G1 arrest and increasing the Sub-G1 population in both lung cancer and normal lung cells. Notably, the extract induced loss of membrane integrity, shrinkage, membrane blebbing, and apoptosis in lung cancer cells, while normal cells exhibited only early apoptosis. Furthermore, the extract exhibited higher toxicity towards NCI-H292 cells, followed by A549 and normal MRC-5 cells in decreasing order of potency. Our results suggest that the ethanolic extract of M. indica L. kernel has significant potential as a novel therapeutic agent for treating lung cancer cells, given its ability to induce apoptosis in cancer cell lines while causing minimal harm to normal cells.

BackgroundTherapy resistance in cancer is often driven by a subpopulation of cells that are temporarily arrested in a non-proliferative G0 state, which is difficult to capture and whose mutational drivers remain largely unknown.ResultsWe develop methodology to robustly identify this state from transcriptomic signals and characterise its prevalence and genomic constraints in solid primary tumours. We show that G0 arrest preferentially emerges in the context of more stable, less mutated genomes which maintain TP53 integrity and lack the hallmarks of DNA damage repair deficiency, while presenting increased APOBEC mutagenesis. We employ machine learning to uncover novel genomic dependencies of this process and validate the role of the centrosomal gene CEP89 as a modulator of proliferation and G0 arrest capacity. Lastly, we demonstrate that G0 arrest underlies unfavourable responses to various therapies exploiting cell cycle, kinase signalling and epigenetic mechanisms in single-cell data.ConclusionsWe propose a G0 arrest transcriptional signature that is linked with therapeutic resistance and can be used to further study and clinically track this state.