Cell Cycle Regulatory Proteins Research Articles

Dual BCL-XL/2 Protac 753B Not Only Potently Induces Apoptosis in Venetoclax-Resistant Primary AML Cells but Also Effectively Eliminates Chemotherapy-Induced Senescent AML Cells

BCL-XL and BCL-2 (BCL-XL/2 ) are key antiapoptotic proteins and validated cancer targets. 753B is a novel BCL-XL/2 proteolysis targeting chimera (PROTAC) that targets both BCL-XL and BCL-2 to the Von Hippel-Lindau (VHL) E3 ligase, leading to BCL-XL/2 ubiquitination and degradation (Lv et al. Nat. Comm. 2021). It exhibits an improved potency against BCL-XL/2 leukemia cells while reduced toxicity to platelets compared to the dual BCL-XL/2 inhibitor navitoclax or ABT263 in vitro. Here we examined the potential therapeutic efficacy of 753B against venetoclax-resistant primary AML cells and chemotherapy-induced senescent AML cells in vitro and in vivo. We first evaluated the sensitivity of 24 genetically diverse leukemia cell lines (17 AML, 5 T-ALL, and 2 AML secondary to myeloproliferative neoplasms (MPN-AML) cell lines) to ABT263, DT2216 (a BCL-XL selective PROTAC) (Khan et.al Nat. Med, 2019) and 753B. 753B induced time and dose-dependent BCL-XL degradation in all lines with DC50 (the concentrations with 50% protein degradation) ranging from 0.01 μM to 0.54 μM. BCL-2 was degraded in all except Loucy cells, with DC50 ranging from 0.02 μM to >1 μM. 753B caused dose-dependent reduction of viability in AML cell lines by CellTiter-Glo (CTG) assay at 24hr (IC50 range 0.01μM - 27.35 μM). 753B was more potent than ABT-263 in 12/17 AML and 3/5 T-ALL lines, with the mean IC50 values of 0.10 μM and 0.48 μM, respectively. The degradation of BCL-XL/2 by 753B was accompanied with MCL-1 upregulation in 10/17 cell lines tested, which was reversely correlated with the IC50. Recent findings indicate that chemotherapy (Ara-C)-induced senescence is associated with chemoresistance (Duy et al., Cancer Discovery 2021), and BCL-XL was previously reported to be the primary survival factor of senescent cells (Chang et al.,Nat. Med.2016). As previously reported, Ara-C indeed induced cellular senescence (SnCs) in MOLM-14 and Kasumi-1 AML cells, with increased cell size, higher senescence-associated β-galactosidase activity, upregulation of cell cycle regulator proteins (p16, p21, p53), and expression of senescence-associated secretory phenotype (IL-8 and CCR5). 753B cleared chemotherapy-induced SnCs by induction of apoptosis. To explore the senolytic mechanism of 753B, we FACS-sorted senescence-high or -low populations based on C12-FDG positivity (fluorogenic substrate di-β-D-galactopyranoside). C12-FDG high senescent AML population expressed higher levels of BCL-XL/2, priming the cells to 753B-induced apoptosis. We next isolated blasts from 16 primary AML samples and tested their sensitivity to 753B. 753B potently reduced cells viability with median IC50 value of 0.23 mM (range 0.02 - 2.29 mM). Similar to cell lines, 753B was more potent in degrading BCL-XL and inducing apoptosis than DT2216 in primary AML cells. 753B showed potency comparable to ABT-263 in all tested AML samples, including seven venetoclax-resistant samples (median IC50, 753B 0.22 mM; ABT-263 0.13 mM). 753B degraded both BCL-XL and BCL-2 in primary myeloblasts in association with the induction of apoptosis. BCL-2 degradation was observed in 4 of 6 samples tested. To investigate the antileukemia activity of 753B in vivo, we developed a patient-derived xenograft (PDX) model using NSG mice injected with AML PDX #8550 (harboring FLT3-ITD, DNMT3A, IDH1, KIT, and NPM1 mutations). Mice were randomized into 2 groups to receive either vehicle or 753B (5 mg/kg intraperitoneally every 4 days) for 3 weeks after leukemia engraftment was confirmed (day 33). Mice tolerated 753B therapy well with no significant changes in body weight and no significant platelet toxicity ascertained by blood counts. 753B as a single agent reduced the circulating leukemia cell burden, serially measured by flow cytometry, and extended median survival time from 61 days to 71 days (P = 0.0023)(Fig. 1A). In summary, the novel BCL-XL/2 PROTAC 753B potently reduced cell viability in leukemia cell lines with diverse genetic background, in primary AML cells including venetoclax-resistant AML blasts, and extended survival of mice harboring human AML PDX in vivo without hematologic toxicity. Our data indicate that co-targeting of BCL-2 and BCL-XL may eliminate senescent AML cells surviving Ara-C chemotherapy, supporting the utility of future combination studies in leukemia. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Anticancer potential of Marina Crystal Minerals (MCM) against the growth of murine mammary adenocarcinoma cells in vivo

In vitro studies have shown that Marina Crystal Minerals (MCM), a crystallized mixture of minerals and trace elements from sea water, possesses apoptotic and immune modulatory effects in human breast cancer cells MDA-MB-231. The current study aimed to evaluate MCM’s anticancer effect in vivo against murine mammary adenocarcinoma cells and to explore its underlying mechanisms. Mice were inoculated intramuscularly with Ehrlich ascites carcinoma (EAC) cells, a breast adenocarcinoma. Tumors became palpable within 9 days. Tumor-bearing mice were injected with MCM intraperitoneally (IP) or intratumorally (IT) at a dose of 40 mg/kg BW for 6 days/week until day 28 post-inoculation. Tumor growth, cell cycle progression, cell cycle regulatory proteins, apoptosis, apoptotic regulatory markers, mitochondrial membrane potential (MMP), natural killer (NK) cell activity, and histopathological effects were investigated. Treatment with MCM reduced tumor volume by 49.4% for IP and 59.5% for IT injection. MCM induced cancer cell apoptosis, as indicated by a sub-G1 peak and confirmed by Annexin V/PI assay and histopathological examination. This was mediated by increased Bax expression, caspase-3 activation, decreased Bcl-2 expression, and MMP disruption. Furthermore, MCM treatment induced G1 cell cycle arrest, mediated through significantly increased expression of p53, p21, and p27 and decreased expression of cyclin D1 and PCNA in cancer cells. Finally, MCM treatment markedly enhanced NK cell cytotoxicity. MCM possesses chemopreventive potential to reduce tumor growth by suppressing cell proliferation, inducing apoptosis in EAC cells via a mitochondrial dependent pathway, and activating the immune system. Our results suggest MCM’s beneficial potential for treating breast adenocarcinoma.

Ginsenoside Rb2 suppresses cellular senescence of human dermal fibroblasts by inducing autophagy

BackgroundGinsenoside Rb2, a major active component of Panax ginseng, has various physiological activities, including anticancer and anti-inflammatory effects. However, the mechanisms underlying the rejuvenation effect of Rb2 in human skin cells have not been elucidated. MethodsWe performed a senescence-associated β-galactosidase staining assay to confirm cellular senescence in human dermal fibroblasts (HDFs). The regulatory effects of Rb2 on autophagy were evaluated by analyzing the expression of autophagy marker proteins, such as microtubule-associated protein 1A/1B-light chain (LC) 3 and p62, using immunoblotting. Autophagosome and autolysosome formation was monitored using transmission electron microscopy. Autophagic flux was analyzed using tandem-labeled GFP-RFP-LC3, and lysosomal function was assessed with Lysotracker. We performed RNA sequencing to identify potential target genes related to HDF rejuvenation mediated by Rb2. To verify the functions of the target genes, we silenced them using shRNAs. ResultsRb2 decreased β-galactosidase activity and altered the expression of cell cycle regulatory proteins in senescent HDFs. Rb2 markedly induced the conversion of LC3-Ⅰ to LC3-Ⅱ and LC3 puncta. Moreover, Rb2 increased lysosomal function and red puncta in tandem-labeled GFP-RFP-LC3, which indicate that Rb2 promoted autophagic flux. RNA sequencing data showed that the expression of DNA damage-regulated autophagy modulator 2 (DRAM2) was induced by Rb2. In autophagy signaling, Rb2 activated the AMPK-ULK1 pathway and inactivated mTOR. DRAM2 knockdown inhibited autophagy and Rb2-restored cellular senescence. ConclusionRb2 reverses cellular senescence by activating autophagy via the AMPK-mTOR pathway and induction of DRAM2, suggesting that Rb2 might have potential value as an antiaging agent.

Panax ginseng Meyer cv. Silvatica phenolic acids protect DNA from oxidative damage by activating Nrf2 to protect HFF-1 cells from UVA-induced photoaging

Ethnopharmacological relevanceLong-wave ultraviolet A (UVA) causes skin aging by damaging the fine structures of the skin, such as elastic fibers and collagen fibers, through oxidation. Currently, the use of plant extracts to protect skin from photoaging is a popular method. Panax ginseng C.A. Meyer exerts commendable anti-photoaging and antioxidant effects. P. ginseng Meyer cv. Silvatica, also known as forest ginseng (FG), is a type of ginseng cultivated by artificially simulating the growth environment of wild ginseng aged >15 years. However, there are only a few reports on its anti-photoaging effect on the skin caused by UVA stimulation.AIM OF THE STUDY: To investigate whether isolated and extracted FG can inhibit skin photoaging as well as to explore its action mechanism. MethodsThe FG extract (FGE) was obtained from the supernatant of FG after water extraction and alcohol precipitation with the D101 resin. The composition and content of phenolic acids in FGE were determined by high-performance liquid chromatography (HPLC). The MTT assay was performed to detect cell viability. The ratio of SA-β-GAL-positive cells, CoL-I level, 8-OHdG concentration, MDA, GSH, GPx, SOD, and CAT activity were measured using relevant kits. Furthermore, cell cycle alterations and ROS accumulation were assessed by flow cytometry. The expressions of p53, p21, p16, and Keap1 protein were detected by Western blotting. The Nrf2 translocation was monitored by immunofluorescence staining. ResultsThe findings revealed that FGE significantly restored UVA injury-induced cell viability, reduced the proportion of SA-β-GAL-positive cells, and increased the level of CoL-I secretion in a dose-dependent manner, where the main ingredients were chlorogenic acid, protocatechuic acid, salicylic acid, p-hydroxybenzoic acid, vanillic acid, ferulic acid, and caffeic acid. Further studies indicated that this phenolic acid mixture (PAM) could alleviate UVA-induced HFF-1 cell cycle arrest and protect the DNA from oxidative damage caused by UVA stimulation. Moreover, the expressions of cell cycle regulatory proteins p53, p21, and p16 and the accumulation of ROS were inhibited, the translocation of Nrf2 into the nucleus was promoted, the expression of Keap1 protein was inhibited, the activity of intracellular antioxidant indicators GSH, GPx, SOD, and CAT was enhanced, and the expression of malondialdehyde (MDA) was inhibited. ConclusionsCollectively, our results demonstrated that FG phenolic acids protect DNA from oxidative damage by activating Nrf2 to safeguard the skin from photoaging induced by UVA stimulation.

Potential role of resveratrol and its nano-formulation as anti-cancer agent.

The uncontrolled and metastatic nature of cancer makes it worse and more unpredictable. Hence, many therapy and medication are used to control and treat cancer. However, apart from this, many medications cause various side effects. In America, nearly 8% of patients admitted to the hospital are due to side effects. Cancer is more seen in people residing in developed countries related of their lifestyle. There are various phytoconstituents molecules in which resveratrol (RSV) is the best-fitted molecule for cancer due to its significantly less adverse effect on the body. RSV inhibits the initiation and progression of cell proliferation due to the modulation of various pathways like the phosphoinositol 3 kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway. RSV downgraded cell cycle-regulated proteins like cyclin E, cyclin D1, and proliferating cell nuclear antigen (PCNA) and induced the release of cytochrome c from the mitochondria, causing apoptosis or programmed cell death (PCD). A great benefit comes with some challenges, hence, RSV does suffer from poor solubility in water i.e. 0.05 mg/mL. It suffers from poor bioavailability due to being highly metabolized by the liver and intestine. Surprisingly, RSV metabolites also induce the metabolism of RSV. Hence, significantly less amount of RSV presented in the urine in the unchanged form. Due to some challenges like poor bioavailability, less aqueous solubility, and retention time in the body, researchers concluded to make the nanocarriers for better delivery. Adopting the technique of nano-formulations, increased topical penetration by up to 21%, improved nano-encapsulation and consequently improved bioavailability and permeability by many folds. Hence, the present review describes the complete profile of RSV and its nano-formulations for improving anti-cancer activity along with a patent survey.

Mesentery AjFGF4-AjFGFR2-ERK pathway modulates intestinal regeneration via targeting cell cycle in echinoderms.

The purpose of the study aims to understand the regeneration process and its cytology mechanism in economic echinoderms. The intestine regeneration process of Apostichopus japonicus was investigated by immunohistochemistry and the cell proliferation was detected by immunofluorescence and flow cytometry. Fibroblast growth factor 4 of A. japonicus (AjFGF4) was screened by RNA-seq analysis and validated to regulate cell proliferation by siAjFGF4 and recombinant-AjFGF4 treatment. The binding and co-localization of AjFGF4 and AjFGFR2 were verified by Co-IP, GST-pull down, and immunofluorescence. Then, the AjFGF4-AjFGFR2-ERK-cell cycle axis was examined by western blot, immunofluorescence, and flow cytometry techniques. The mesentery was served as the epicenter of intestinal regeneration via activating cell proliferation and other cellular events. Mechanically, AjFGF4-mediated cell proliferation was dependent on the binding to its receptor AjFGFR2, and then triggered the conserved ERK-MAPK pathway but not JNK and p38 pathway. The activated ERK-MAPK subsequently mediated the expression of cell cycle regulatory proteins of CDK2, Cyclin A, and Cyclin B to promote cell proliferation. We provide the first functional evidence that AjFGF4-AjFGFR2-ERK-cell cycle axis mediated cell proliferation was the engine for mesentery-derived intestine regeneration in echinoderms.

NAV3 is a genetic determinant of myocardial recovery in dilated cardiomyopathy and attenuates cardiac fibrosis

Abstract Background A genome-wide association study (GWAS) assessing change in left ventricular ejection fraction (LVEF) in dilated cardiomyopathy (DCM), a surrogate marker of morbidity and mortality in heart failure (HF), had not been performed previously and could provide insight into novel biological pathways that could lead to the development of new drugs that might target myocardial recovery. The presence and extent of cardiac fibrosis in DCM is independently associated with myocardial recovery and cardiovascular mortality. Purpose To identify the biological relevance of genetic targets that are associated with change in LVEF in patients with DCM. Methods A GWAS was performed using DNA from 686 patients with recent onset DCM who were on standard HF therapy using change in LVEF at a median of 6 months after initial diagnosis. Cultured human cardiac fibroblasts (HCFs) were used as an in vitro model to study the functional and biological relevance of the gene target identified in the GWAS. Specifically, HCFs were transfected with siRNA by using the Lipofectamine™ RNAiMAX Transfection Reagent for gene knockdown (KD). RNA-seq was performed using the Illumina TruSeq protocol with expression analysis conducted with the EdgeR package. Ingenuity Pathway Analysis was used. Results A single-nucleotide polymorphism, rs11105445(G>A), mapping to the neuron navigator 3 (NAV3) gene (rs11105445, p=2.37E-07; beta 2.74±0.53) was associated with improvement in LVEF. We performed a phenome-wide association study using data from the UK Biobank and demonstrated that genetic variation in NAV3 was significantly associated with HF mortality (p=3.2E-28), highlighting the potential importance of this gene in HF. Using GTEx data we demonstrated that in LV tissue the minor allele A was associated with ↓NAV3 expression (p=0.03) suggesting that ↓NAV3 expression might be associated with improvement in LVEF. We demonstrated that NAV3 KD significantly ↓TGF-β1 mediated HCF transdifferentiation into myofibroblasts, ↓α-smooth muscle actin (ACTA2) and ↓collagen I (COL1A1), therefore NAV3 KD was anti-fibrotic (see Figure 1), 1a. HCFs treated by vehicle/TGF-β1 after KD of NAV3/ctrl, and ACTA2 and COL1A1 were analyzed by qPCR; 1b. Representative immunofluorescence staining for α-SMA (in green), RNA-seq after NAV3 KD followed by pathway analysis suggested that NAV3 exerted its effect by regulating cell cycle related proteins (Figure 2), 2a. Volcano plot shows significant differentially expressed genes identified by RNA-seq analysis (down-regulated in blue, up-regulated in red); 2b. NAV3 KD significantly increased expression of cell cycle related proteins, which was validated by Western blot. Conclusions Decreased expression of NAV3 is associated with myocardial recovery in DCM, most likely due to its anti-fibrotic effect via direct regulation of cell cycle proteins. The role of NAV3 as a novel therapeutic target in DCM needs to be explored. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): Mayo Clinic Center for Individualized MedicineMayo Clinic Department of Cardiovascular Medicine

Antitumor Potential of Sericite Treatment Mediated by Cell Cycle Arrest in Triple-Negative MDA-MB231 Breast Cancer Cells.

Breast cancer is the most common cancer and the leading cause of cancer-related mortality among females worldwide. Triple-negative breast cancer (TNBC) accounts for about 10–15% of all breast cancers and is usually more aggressive and has a poorer prognosis. Sericite has been known to have antitumor and immune-stimulatory effects. Although the chemopreventive potential of sericite has been demonstrated in other cancers, its molecular pathways in TNBC still require investigation. Thus, in the present study, the antitumor mechanism of sericite against MDA-MB231 breast cancer cells was examined in vitro and in an in vivo xenograft mouse model. Sericite treatment reduced cell proliferation and cell proliferation marker proliferating cell nuclear antigen (PCNA) in MDA-MB231 cells. It also decreased the total cell number and arrested cells in the G0/G1 phase of the cell cycle with an increase in the phosphorylation of P53 and upregulation of cell cycle regulatory proteins P21 and P16. In addition, sericite treatment also induced apoptosis signaling, which was evident by the upregulation of apoptotic protein markers cleaved caspases 3 and 9. A reduction in reactive oxygen species (ROS), NADPH oxidase 4 (NOX4), p22phox, and heat shock proteins (HSPs) was also observed. Similar results were obtained in vivo with significantly reduced tumor volume in sericite-administered mice. Collectively, these findings suggest that sericite has antitumor potential based on its property to induce cell cycle arrest and apoptotic cell death and therefore could serve as a potential therapeutic agent and crucial candidate in anticancer drug development for TNBC.

Allyl-, Butyl- and Phenylethyl-Isothiocyanate Modulate Akt-mTOR and Cyclin-CDK Signaling in Gemcitabine- and Cisplatin-Resistant Bladder Cancer Cell Lines.

Combined cisplatin–gemcitabine treatment causes rapid resistance development in patients with advanced urothelial carcinoma. The present study investigated the potential of the natural isothiocyanates (ITCs) allyl-isothiocyanate (AITC), butyl-isothiocyanate (BITC), and phenylethyl-isothiocyanate (PEITC) to suppress growth and proliferation of gemcitabine- and cisplatin-resistant bladder cancer cells lines. Sensitive and gemcitabine- and cisplatin-resistant RT112, T24, and TCCSUP cells were treated with the ITCs, and tumor cell growth, proliferation, and clone formation were evaluated. Apoptosis induction and cell cycle progression were investigated as well. The molecular mode of action was investigated by evaluating cell cycle-regulating proteins (cyclin-dependent kinases (CDKs) and cyclins A and B) and the mechanistic target of the rapamycin (mTOR)-AKT signaling pathway. The ITCs significantly inhibited growth, proliferation and clone formation of all tumor cell lines (sensitive and resistant). Cells were arrested in the G2/M phase, independent of the type of resistance. Alterations of both the CDK–cyclin axis and the Akt–mTOR signaling pathway were observed in AITC-treated T24 cells with minor effects on apoptosis induction. In contrast, AITC de-activated Akt–mTOR signaling and induced apoptosis in RT112 cells, with only minor effects on CDK expression. It is concluded that AITC, BITC, and PEITC exert tumor-suppressive properties on cisplatin- and gemcitabine-resistant bladder cancer cells, whereby the molecular action may differ among the cell lines. The integration of these ITCs into the gemcitabine-/cisplatin-based treatment regimen might optimize bladder cancer therapy.

Proteomic profiling reveals neuronal ion channel dysregulation and cellular responses to DNA damage-induced cell cycle arrest and senescence in human neuroblastoma SH-SY5Y cells exposed to cypermethrin

Cypermethrin (CYP), a synthetic pyrethroid of class II, is widely used as a pesticide worldwide. The primary target of cypermethrin is a voltage-gated sodium channel. The neurotoxicity of CYP has been extensively studied in terms of affecting neuronal development, increasing cellular oxidative stress, and apoptosis. However, little is known about how it affects the expression of channel proteins involved in synaptic transmission, as well as the effects of cypermethrin on DNA damage and cell cycle processes. We found that the ligand and voltage-gated calcium channels and proteins involved in synaptic transmission including NMDA 1 receptor subunit, alpha 1A-voltage-dependent calcium channel, synaptotagmin-17, and synaptojanin-2 were downregulated in CYP-treated cells. After 48 h of CYP exposure, cell viability was reduced with flattened and enlarged morphology. The levels of 23 proteins regulating cell cycle processes were altered in CYP-treated cells, according to a proteomic study. The cell cycle analysis showed elevated G0/G1 cell cycle arrest and DNA fragmentation at the sub-G0 stage after CYP exposure. CYP treatment also increased senescence-associated β-galactosidase positive cells, DNA damage, and apoptotic markers. Taken together, the current study showed that cypermethrin exposure caused DNA damage and hastened cellular senescence and apoptosis via disrupting cell cycle regulation. In addition, despite its primary target sodium channel, CYP might cause synaptic dysfunction via the downregulation of synaptic proteins and dysregulation of synapse-associated ion channels.

Expression of Cell-Cycle Regulatory Proteins pRb, Cyclin D1, and p53 Is Not Associated with Recurrence Rates of Equine Sarcoids.

Simple SummaryExpression of cell-cycle regulatory proteins pRB, Cyclin D1, and p53 is not associated with recurrence rates of equine sarcoids. Sarcoids are common tumors of equids, and since the pathogenesis and Bovine Papillomavirus (BPV) mechanism of tumorigenesis is not fully understood yet, we investigated the expression of cell cycle regulatory proteins pRB, Cyclin D1, and p53 to understand whether BPV and Human Papillomavirus (HPV) share similar mechanisms of action. The expression pattern of these proteins in a series of BPV-positive equine sarcoids is different from HPV-induced tumors. Moreover, their expression is not correlated with the recurrence or occurrence of sarcoids in new body sites.Sarcoids are among the most common tumors diagnosed in equids; their association with bovine papillomaviruses (BPV) infection has been widely reported, but the mechanism of carcinogenesis has not been fully elucidated. To verify whether BPV infection causes dysregulation of the pRb-Cyclin D1-p16CDKN2A-p53 pathway as reported for human papillomavirus (HPV), the study employed immunohistochemistry to test 55 equine sarcoid biopsies for the expression of pRb, Cyclin D1, and p53 cell cycle regulatory proteins and to evaluate the proliferative rate through Ki67. High Cyclin D1 and pRb expression were observed in 51% and 80% of cases, respectively, while low expression was observed in 49% and 20% of cases, respectively. Significantly higher Ki67 proliferation indexes were observed in fibroblastic, nodular, and mixed sarcoids compared to the occult and verrucous. High proliferation was significantly associated with high Cyclin D1 expression. In contrast with previous studies, p53 positivity was not observed in the cases examined in this study. Moreover, follow-up analysis revealed that fibroblastic, mixed sarcoids were associated with significantly higher local recurrence rates while the verrucous subtype was associated with higher rates of new sarcoid development at distant sites.

Members of SIAMESE-RELATED Class Inhibitor Proteins of Cyclin-Dependent Kinase Retard G2 Progression and Increase Cell Size in Arabidopsis thaliana.

Cell size requires strict and flexible control as it significantly impacts plant growth and development. Unveiling the molecular mechanism underlying cell size control would provide fundamental insights into plants’ nature as sessile organisms. Recently, a GRAS family transcription factor SCARECROW-LIKE28 (SCL28) was identified as a determinant of cell size in plants; specifically, SCL28 directly induces a subset of SIAMESE-RELATED (SMR) family genes encoding plant-specific inhibitors of cyclin-dependent kinases (i.e., SMR1, SMR2, SMR6, SMR8, SMR9, SMR13, and SMR14), thereby slowing down G2 phase progression to provide the time to increase cell volume. Of the SMR genes regulated by SCL28, genetic analysis has demonstrated that SMR1, SMR2, and SMR13 cooperatively regulate the cell size downstream of SCL28 in roots and leaves, whereas other SMR members’ contribution remains unexplored. This study shows that in root meristematic cells, SMR9 redundantly participates in cell size control with SMR1, SMR2, and SMR13. Moreover, our cell cycle analysis provides the first experimental evidence that SMR proteins inhibit the G2 progression of proliferating cells. Overall, these findings illuminate the diverse yet overlapping roles of SMR proteins in cell cycle regulation while reinforcing that SMRs are essential downstream effectors of SCL28 to modulate G2 progression and cell size.

Cell Division Cycle-Associated Protein 3 (CDCA3) Is a Potential Biomarker for Clinical Prognosis and Immunotherapy in Pan-Cancer.

CDCA3 is an essential regulator in cell mitosis and can regulate many physiological and pathological processes in the human body by stimulating certain proteins such as cell cycle regulatory proteins, transcription factors, and signal transduction molecules. Although several studies have shown that dysregulation of CDCA3 is a common phenomenon in human cancers, no systematic pan-cancer analysis has been performed. In this study, we comprehensively investigated the role of CDCA3 in 33 human cancer types by utilizing multiple cancer-related databases and bioinformatics analysis tools, including TCGA, GTEx, GEPIA, TIMER, STRING, Metascape, and Cytoscape. Evidence from bioinformatics databases shows that CDCA3 is overexpressed in almost all human cancer types, and its overexpression is significantly associated with survival in patients with more than ten cancer types. CDCA3 expression positively correlates with immune cell infiltration levels in multiple human cancer types. Furthermore, the results of the GSEA analysis revealed that overexpression of CDCA3 may promote the malignant progression of cancer by activating various oncogenic signaling pathways in human cancers. In conclusion, our pan-cancer analysis provides a comprehensive overview of the oncogenic role of CDCA3 in multiple human cancer types, suggesting that CDCA3 may serve as a potential therapeutic target and prognostic biomarker in multiple human cancer types.

Lentinan-functionalized selenium nanoparticles induce apoptosis and cell cycle arrest in human colon carcinoma HCT-116 cells.

Selenium nanoparticles (SeNPs) have gained extensive attention for their excellent biological activity and low toxicity. However, SeNPs are extremely liable to aggregate into non-bioactive or gray elemental selenium, which limits their application in the biomedicine field. This study aimed to prepare stable SeNPs by using lentinan (LNT) as a template and evaluate its anti-colon cancer activity. The average particle diameter of obtained lentinan-selenium nanoparticles (LNT-SeNPs) was approximately 59 nm and presented zero-valent, amorphous, and spherical structures. The monodisperse SeNPs were stabilized by LNT through hydrogen bonding interactions. LNT-SeNPs solution remained highly stable at 4°C for at least 8 weeks. The stability of LNT-SeNPs solution sharply decreased under high temperature and strong acidic conditions. LNT-SeNPs showed no obvious cytotoxic effect on normal cells (IEC-6) but significantly inhibited the proliferation of five colon cancer cells (HCT-116, HT-29, Caco-2, SW620, and CT26). Among them, LNT-SeNPs exhibited the highest sensitivity toward HCT-116 cells with an IC50 value of 7.65 μM. Also, LNT-SeNPs displayed better cancer cell selectivity than sodium selenite and selenomethionine. Moreover, LNT-SeNPs promoted apoptosis of HCT-116 cells through activating mitochondria-mediated apoptotic pathway. Meanwhile, LNT-SeNPs induced cell cycle arrest at G0/G1 phase in HCT-116 cells via modulation of cell cycle regulatory proteins. The results of this study indicated that LNT-SeNPs possessed strong potential application in the treatment of colorectal cancer (CRC).

Dynactin 2 acts as an oncogene in hepatocellular carcinoma through promoting cell cycle progression

BackgroundDynactin (DCTN) can activate cytoplasmic dynein and drive intracellular organelle transport containing six family members (DCTN1 to DCTN6). The DCTN family has been studied as cancer-related genes or biomarkers in various cancers. Nevertheless, in hepatocellular carcinoma (HCC), the functions and prognostic roles of the DCTN family have been unexplored. MethodsWe evaluated the diagnostic and survival effects of DCTN subunits in HCC through bioinformatics analysis and validated the results of bioinformatics by our data to address this problem. ResultsThe results of bioinformatics analysis found that DCTN2 was a significant prognostic factor in HCC, and high-level DCTN2 can predict poor patient survival in HCC. Cox regression analysis also suggested that DCTN2 (hazard ratio = 1.748, 95% confidence interval 1.190–2.568, P = 0.004) is an independent prognostic factor for patient survival. Western blot and quantitative reverse transcription-polymerase chain reaction assays confirmed that the protein and mRNA expression levels of DCTN2 were upregulated in HCC cell lines. The proliferation, invasion, and migration were decreased and cell apoptosis was enhanced after DCTN2 was knocked down in Huh7 and Hep3B cells. DCTN2 promoted the cell cycle progression through regulating the expression of cell cycle regulatory proteins cyclin-dependent kinase 4, Cyclin D1, and p21. ConclusionsWe propose that DCTN2 can serve as a prognostic marker for HCC. DCTN2 acts as an oncogene and promotes the cell cycle progression through the G1/S phase-related signaling pathway.

Cyclin-dependent kinase inhibitors in malignant hematopoiesis.

The cell-cycle is a tightly orchestrated process where sequential steps guarantee cellular growth linked to a correct DNA replication. The entire cell division is controlled by cyclin-dependent kinases (CDKs). CDK activation is balanced by the activating cyclins and CDK inhibitors whose correct expression, accumulation and degradation schedule the time-flow through the cell cycle phases. Dysregulation of the cell cycle regulatory proteins causes the loss of a controlled cell division and is inevitably linked to neoplastic transformation. Due to their function as cell-cycle brakes, CDK inhibitors are considered as tumor suppressors. The CDK inhibitors p16INK4a and p15INK4b are among the most frequently altered genes in cancer, including hematopoietic malignancies. Aberrant cell cycle regulation in hematopoietic stem cells (HSCs) bears severe consequences on hematopoiesis and provokes hematological disorders with a broad array of symptoms. In this review, we focus on the importance and prevalence of deregulated CDK inhibitors in hematological malignancies.

The cell cycle of phytoplankton: A review

AbstractPhytoplankton play an enormously important role in ecology and serve as critical food for aquatic organisms. The phytoplankton population rapidly increases in number after continuous cell cycles. Thus, understanding the cell cycle of phytoplankton is fundamental to the aquatic ecosystem research. The eukaryotic cell cycle has been clarified; however, unique characteristics exist in phytoplankton. Their cell cycle progression either differs among species or varies with environmental changes. Here, we review the cell cycle progression of the eukaryotic phytoplankton and its response to environmental factors, introduce the cell cycle research methods, highlight the identified cell cycle regulatory proteins, and discuss prospects for future research directions.

Discovery of N-benzylarylamide derivatives as novel tubulin polymerization inhibitors capable of activating the Hippo pathway

Novel N-benzylarylamide saderivatives were designed and synthesized, and their antiproliferative activities were explored. Some of 51 target compounds exhibited potent inhibitory activities against MGC-803, HCT-116 and KYSE450 cells with IC50 values in two-digit nanomolar. Compound I-33 (MY-875) displayed the most potent antiproliferative activities against MGC-803, HCT-116 and KYSE450 cells (IC50 = 0.027, 0.055 and 0.067 μM, respectively) and possessed IC50 values ranging from 0.025 to 0.094 μM against other 11 cancer cell lines. Further mechanism studies indicated that compound I-33 (MY-875) inhibited tubulin polymerization (IC50 = 0.92 μM) by targeting the colchicine bingding site of tubulin. Compound I-33 (MY-875) disrupted the construction of the microtubule networks and affected the mitosis in MGC-803 and SGC-7901 cells. In addition, although it acted as a colchicine binding site inhibitor, compound I-33 (MY-875) also activated the Hippo pathway to promote the phosphorylation status of MST and LATS, resulting in the YAP degradation in MGC-803 and SGC-7901 cells. Due to the degradation of YAP, the expression levels of TAZ and Axl decreased. Because of the dual actions on colchicine binding site and Hippo pathway, compound I-33 (MY-875) dose-dependently inhibited cell colony formatting ability, arrested cells at the G2/M phase and induced cells apoptosis in MGC-803 and SGC-7901 cells. Moreover, compound I-33 (MY-875) could regulate the levels of cell cycle and apoptosis regulatory proteins in MGC-803 and SGC-7901 cells. Furthermore, molecular docking analysis suggested that the hydrogen bond and hydrophobic interactions made compound I-33 (MY-875) well bind into the colchicine binding site of tubulin. Collectively, compound I-33 (MY-875) is a novel anti-gastric cancer agent and deserves to be further investigated for cancer therapy by targeting the colchicine binding site of tubulin and activating the Hippo pathway.

Biosynthesized tin oxide-sodium alginate-polyethylene glycol-carvacrol nanocomposite shows anticancer activity on esophagus squamous carcinoma cells

Esophagus cancer is the sixth leading cause of cancer-related mortalities worldwide. In this study, we synthesized a biocompatible nanocomposite with green synthesized tin oxide using carvacrol, sodium allyl, and polyethylene glycol. Carvacrol is a phenolic monoterpenoid extracted from the essential oils of the plants belonging to the Lamiaceae family. Carvacrol possesses immense pharmacological properties such as antioxidant, antiviral, anticancer, etc. In this study, we assessed the efficacy of Tin oxide-Sodium alginate-Polyethylene glycol-Carvacrol (SnO2-SAPG-Carvacrol) nanocomposite. The synthesized nanocomposite was subjected to spectroscopic analysis, FTIR spectroscopic analysis, FESEM & EDAX analysis, TEM, and XRD & DLS analysis. The antimicrobial efficacy of SnO2-SAPG-Carvacrol nanocomposite against various microorganisms was analyzed using the disc diffusion method. MTT assay was performed to detect the cytotoxic effect of SnO2-SAPG-Carvacrol nanocomposite on KYSE-150–7 cells esophagus squamous carcinoma cell line. The apoptotic efficacy of SnO2-SAPG-Carvacrol nanocomposite was assessed with staining techniques such as DCFH-DA, Rhodamine 123 staining, and AO/EtBr staining. Oxidative stress markers were quantified to detect the anticancer property of SnO2-SAPG-Carvacrol nanocomposite. To analyze the anti-migratory effect we have done a transwell chamber assay. To confirm the anticancer potency of SnO2-SAPG-Carvacrol nanocomposite the cell cycle regulatory and apoptotic regulatory proteins were quantified. Characterization analysis of SnO2-SAPG-Carvacrol nanocomposite confirms it has a potent nanocomposite that can be utilized as a drug. MTT assay and staining results of SnO2-SAPG-Carvacrol nanocomposite treated KYSE-150–7 cells prove the apoptotic property of nanocomposite synthesized. SnO2-SAPG-Carvacrol nanocomposite treatment on KYSE-150–7 cells significantly increased oxidative stress thereby inducing apoptosis in KYSE-150–7 cells. The anti-migratory property of synthesized nanocomposite was confirmed with the transwell chamber assay. The ELISA results of cell regulatory and apoptotic regulatory protein confirm the anticancer activity of SnO2-SAPG-Carvacrol nanocomposite. Overall our results confirm that SnO2-SAPG-Carvacrol nanocomposite is a potent anticancer drug.

Targeting cyclin-dependent kinase 1 (CDK1) in cancer: molecular docking and dynamic simulations of potential CDK1 inhibitors.

Cell cycle dysregulation is a characteristic hallmark of malignancies, which results in uncontrolled cell proliferation and eventual tumor formation. Cyclin-dependent kinase 1 (CDK1) is a member of the family of cell cycle regulatory proteins involved in cell cycle maintenance. Given that overexpression of CDK1 has been associated with cancer, CDK1 inhibitors may restore equilibrium to the skewed cell cycle system and operate as an effective therapeutic drug. This study aimed to identify and classify inhibitors having a higher affinity for CDK1 and also evaluate the expression pattern and prognostic relevance of CDK1 in a wide range of cancers. We investigated therapeutic molecules structurally similar to dinaciclib for their ability to inhibit CDK1 selectively. To assess the therapeutic potential of screened Dinaciclib analogs, we used drug likeliness analysis, molecular docking, and simulation analysis. CDK1 was found to be highly upregulated across several malignancies and is associated with poor overall and relapse-free survival. Molecular docking and dynamics evaluation identified two novel dinaciclib analogs as potent CDK1 inhibitors with high binding affinity and stability compared to dinaciclib. The results indicate that increased CDK1 expression is associated with decreased OS and RFS. Additionally, dinaciclib analogs are prospective replacements for dinaciclib since they exhibit increased binding affinity, consistent with MDS findings, and have acceptable ADMET qualities. The discovery of new compounds may pave the road for their future application in cancer prevention through basic, preclinical, and clinical research.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12032-022-01748-2.