Proportion Of Cells In G1 Phase Research Articles

Rujifang inhibits triple-negative breast cancer growth via the PI3K/AKT pathway

Ethnopharmacological relevanceRujifang (RJF) constitutes a traditional Chinese medicinal compound extensively employed in the management of triple-negative breast cancer (TNBC). However, information regarding its potential active ingredients, antitumor effects, safety, and mechanism of action remains unreported. Aim of the studyTo investigate the efficacy and safety of RJF in the context of TNBC. Materials and methodsWe employed the ultra high-performance liquid chromatography-electrospray four-pole time-of-flight mass spectrometry technique (UPLC/Q-TOF-MS/MS) to scrutinize the chemical constituents of RJF. Subcutaneously transplanted tumor models were utilized to assess the impact of RJF on TNBC in vivo. Thirty female BLAB/c mice were randomly divided into five groups: the model group, cyclophosphamide group, and RJF high-dose, medium-dose, and low-dose groups. A total of 1 × 106 4T1 cells were subcutaneously injected into the right shoulder of mice, and they were administered treatments for a span of 28 days. We conducted evaluations on blood parameters, encompassing white blood cell count (WBC), red blood cell count (RBC), hemoglobin (HGB), platelet count (PLT), neutrophils, lymphocytes, and monocytes, as well as hepatorenal indicators including alkaline phosphatase (ALP), glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), albumin, and creatinine (CRE) to gauge the safety of RJF. Ki67 and TUNEL were detected via immunohistochemistry and immunofluorescence, respectively. We prepared RJF drug-containing serum for TNBC cell lines and assessed the in vitro inhibitory effect of RJF on tumor cell growth through the CCK8 assay and cell cycle analysis. RT-PCR was employed to detect the mRNA expression of cyclin-dependent kinase and cyclin-dependent kinase inhibitors in tumor tissues, and Western blot was carried out to ascertain the expression of cyclin and pathway-related proteins. Results100 compounds were identified in RJF, which consisted of 3 flavonoids, 24 glycosides, 18 alkaloids, 3 amino acids, 8 phenylpropanoids, 6 terpenes, 20 organic acids, and 18 other compounds. In animal experiments, both CTX and RJF exhibited substantial antitumor effects. RJF led to an increase in the number of neutrophils in peripheral blood, with no significant impact on other hematological indices. In contrast, CTX reduced red blood cell count, hemoglobin levels, and white blood cell count, while increasing platelet count. RJF exhibited no discernible influence on hepatorenal function, whereas Cyclophosphamide (CTX) decreased ALP, GOT, and GPT levels. Both CTX and RJF reduced the expression of Ki67 and heightened the occurrence of apoptosis in tumor tissue. RJF drug-containing serum hindered the viability of 4T1 and MD-MBA-231 cells in a time and concentration-dependent manner. In cell cycle experiments, RJF diminished the proportion of G2 phase cells and arrested the cell cycle at the S phase. RT-PCR analysis indicated that RJF down-regulated the mRNA expression of CDK2 and CDK4, while up-regulating that of P21 and P27 in tumor tissue. The trends in CDKs and CDKIs protein expression mirrored those of mRNA expression. Moreover, the PI3K/AKT pathway displayed downregulation in the tumor tissue of mice treated with RJF. ConclusionRJF demonstrates effectiveness and safety in the context of TNBC. It exerts anti-tumor effects by arresting the cell cycle at the S phase through the PI3K-AKT pathway.

Total glucosides of Rhizoma Smilacis Glabrae: a therapeutic approach for psoriasis by regulating Th17/Treg balance.

Total glucosides of Rhizoma Smilacis Glabrae (RSG) are selective immunosuppressants that exhibit primary efficacy in the treatment of rheumatoid arthritis through targeted inhibition of activated T cells. In this study, we aimed to investigate the potential application of RSG in the treatment of psoriasis and elucidate its mechanism of action and material basis. Our findings revealed significant improvements upon administration of RSG in an imiquimod (IMQ)-induced psoriasis model. These improvements were characterized by a remarkable increase in the number of tail scales in mice and a substantial amelioration of skin erythema, ulceration, and flaking. By transcriptome sequencing and T-cell flow sorting assay, we identified notable effects of RSG on the modulation of various cellular processes. Specifically, RSG prominently down-regulated the Th17/Treg ratio in damaged skin tissues and reduced the proportion of G2 phase cells. Furthermore, RSG exhibited a stimulatory effect on the proliferation and differentiation of epithelial cells. Of particular interest, we discovered that β-sitosterol, sitostenone, stigmasterol, smiglanin, and cinchonain Ib displayed potent inhibitory effects on the IL-17-mediated inflammatory response in HaCaT cells. In summary, our study highlights the therapeutic potential of RSG in the treatment of psoriasis, attributed to its ability to regulate the Th17/Treg balance. These findings contribute to the development of new indications for RSG and provide a solid theoretical foundation for further exploration in this field.

Effects of miR-144-3p on Proliferation, Cell Cycle and Apoptosis of K562 Cells

To investigate the effects of miR-144-3p on cell proliferation, cell cycle and apoptosis of blast phase chronic myelogenous leukemia (CML) K562 cells. K562 cells were cultured in vitro and mimics negative control, hsa-miR-144-3p mimics, inhibitor negative control and miR-144-3p inhibitor were respectively transfected into K562 cells with transfection reagents. The cells were divided into five groups including blank control, mimics negative control, miR-144-3p mimics, inhibitor negative control and miR-144-3p inhibitor. After transfection, the cell proliferation activity was detected by CCK-8 assay. The cell cycle distribution and apoptosis were detected by flow cytometry. Compared with the blank control and mimics negative control groups, the proliferation rate of miR-144-3p mimics group was significantly decreased (P<0.05), the proportion of S phase cells was markedly increased (P<0.05), while the proportion of G1 phase cells was obviously decreased (P<0.05), and the apoptosis rate was significantly increased (P<0.05). Compared with the blank control and inhibitor negative control groups, the proliferation rate of miR-144-3p inhibitor group was obviously increased (P<0.05), the proportion of S phase cells was markedly decreased (P<0.05), while the proportion of G1 phase cells was obviously increased (P<0.05), and the apoptosis rate was significantly decreased (P<0.05). miR-144-3p can inhibit the proliferation and promote apoptosis of K562 cells, affect the cell cycle, and block K562 cells in S phase, which indicates that miR-144-3p is involved in the cell cycle activity of CML during blastic phase.

Differentiation Capacity of Bone Marrow-Derived Rat Mesenchymal Stem Cells from DsRed and Cre Transgenic Cre/loxP Models

Cre/loxP recombination is a well-established technique increasingly used for modifying DNA both in vitro and in vivo. Nucleotide alterations can be edited in the genomes of mammalian cells, and genetic switches can be designed to target the expression or excision of a gene in any tissue at any time in animal models. In this study, we propose a system which worked via the Cre/loxP switch gene and DsRed/emGFP dual-color fluorescence imaging. Mesenchymal stem cells (MSCs) can be used to regenerate damaged tissue because of their differentiation capacity. Although previous studies have presented evidence of fusion of transplanted MSCs with recipient cells, the possibility of fusion in such cases remains debated. Moreover, the effects and biological implications of the fusion of MSCs at the tissue and organ level have not yet been elucidated. Thus, the method for determining this issue is significant and the models we proposed can illustrate the question. However, the transgenic rats exhibited growth slower than that of wild-type rats over several weeks. The effects on the stemness, proliferation, cell cycle, and differentiation ability of bone marrow–derived rat MSCs (BM-rMSCs) from the models were examined to ensure our design was appropriate for the in vivo application. We demonstrated that MSC surface markers were maintained in DsRed and Cre transgenic rMSCs (DsRed-rMSCs and Cre-rMSCs, respectively). A WST-8 assay revealed decreased proliferative activity in these DsRed-rMSCs and Cre-rMSCs; this result was validated through cell counting. Furthermore, cell cycle analysis indicated a decrease in the proportion of G1-phase cells and a concomitant increase in the proportion of S-phase cells. The levels of cell cycle–related proteins also decreased in the DsRed-rMSCs and Cre-rMSCs, implying decelerated phase transition. However, the BM-rMSCs collected from the transgenic rats did not exhibit altered adipogenesis, osteogenesis, or chondrogenesis. The specific markers of these types of differentiation were upregulated after induction. Therefore, BM-rMSCs from DsRed and Cre transgenic models can be used to investigate the behavior of MSCs and related mechanisms. Such application may further the development of stem cell therapy for tissue damage and other diseases.

MiR-106b-5p regulates esophageal squamous cell carcinoma progression by binding to HPGD

BackgroundSeveral studies have documented the key role of microRNAs (miRNAs) in esophageal squamous cell carcinoma (ESCC). Although the expression of the 15-hydroxyprostaglandin dehydrogenase (HPGD) gene and miR-106b-5p are reportedly linked to cancer progression, their underlying mechanisms in ESCC remain unclear.MethodsmRNA and miRNA expression in ESCC tissues and cells were analyzed using RT-qPCR. Luciferase and RNA pull-down assays were used to identify the interaction between miR-106b-5p and HPGD. Xenograft and pulmonary metastasis models were used to assess tumor growth and metastasis. CCK-8, BrdU, colony formation, adhesion, cell wound healing, Transwell, and caspase-3/7 activity assays, and flow cytometry and western blot analyses were used to examine the function of miR-106-5p and HPGD in ESCC cell lines.ResultsThe findings revealed that miR-106b-5p expression was upregulated in ESCC tissues and cell lines. miR-106b-5p augmented cellular proliferation, colony formation, adhesion, migration, invasion, and proportion of cells in the S-phase, but reduced apoptosis and the proportion of cells in G1-phase. Silencing of miR-106-5p inhibited tumor growth in vivo and pulmonary metastasis. Although HPGD overexpression suppressed proliferation, colony formation, adhesion, migration, and invasion of ESCC cells, it promoted apoptosis and caused cell cycle arrest of the ESCC cells. The results also indicated a direct interaction of HPGD with miR-106b-5p in ESCC cells. Furthermore, miR-106b-5p inhibited HPGD expression, thereby suppressing ESCC tumorigenesis.ConclusionOur data suggest that miR-106b-5p enhances proliferation, colony formation, adhesion, migration, and invasion, and induces the cycle progression, but represses apoptosis of ESCC cells by targeting HPGD. This suggests that the miR-106b-5p/HPGD axis may serve as a promising target for the diagnosis and treatment of ESCC.

Downregulation of CPT2 promotes proliferation and inhibits apoptosis through p53 pathway in colorectal cancer

BackgroundDownregulation of Carnitine palmitoyltransferase-2 (CPT2) has been shown to be highly associated with the progression of several cancers, but little known about its expression, biological functions and mechanisms in colorectal cancer (CRC). MethodsBioinformatics analysis of The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) data sets was used to explore the expression of CPT2, the relationship between CPT2 expression and clinicopathologic features, as well as the overall survival of CRC. Cox's proportional hazards regression model was used to analyze independent prognostic factors of CRC. In vitro, CRC tissues were analyzed by RT-qPCR, IHC, IF and western blotting to verify CPT2 expression. Colony formation, CCK-8, cell cycle, apoptosis, transwell and wound healing assays were performed to examine the functions of CPT2 in CRC. In vivo, nude mouse xenograft experiment was used to further examine the effect of CPT2 on tumorigenesis. Furthermore, gene set enrichment analysis (GSEA) was conducted to explore the downstream pathway of CPT2. The regulation of p53 pathway by CPT2 was verified by RT-qPCR and Western blotting. ResultsCPT2 expression was frequently downregulated in CRC and correlated with poor prognosis. Low CPT2 expression was significantly associated with age, lymph node metastasis, distant metastasis and TMN stage. Univariate and multivariate analysis indicated that low CPT2 expression was an independent prognostic factor for poorer overall survival. Functionally, overexpression of CPT2 in CRC cells induced growth suppression, cell cycle arrest at the G1 phase, enhanced apoptosis and reduced cell migration and invasion. Conversely, knockdown of CPT2 contributed to cell proliferation, migration and invasion, increased the proportion of S phase cells, decreased the proportion of G1 phase cells and inhibited apoptosis. Mechanistically, we found that CPT2 overexpression can increase p53 expression by activating p-p53, leading to p21, Bax, cleaved caspase-9, cleaved caspase-3 and cleaved PARP activation and Bcl2, MDM2 deactivation, thereby inhibiting tumor proliferation and promoting apoptosis. CPT2 knockdown yielded opposite results. ConclusionThese findings suggest that CPT2 may be a novel prognostic marker of CRC and downregulation of CPT2 can promote proliferation and inhibit apoptosis through p53 pathway in CRC. Strategies targeting CPT2 may be developed as therapies for CRC.

Effect of miR-384-targeting LINC00491 on proliferation, migration and invasion of tongue squamous cell carcinoma cells

&#x0D; &#x0D; &#x0D; &#x0D; Purpose: To investigate the effect of long-chain non-coding RNA LINC00491 (LncRNA LINC00491) on the proliferation, migration and invasion of tongue squamous cell carcinoma (TSCC) cells, and the underlying mechanism.&#x0D; Methods: Real-time quantitative polymerase chain reaction (qRT-PCR) was applied to determine the expressions of LINC00491 and micro-RNA-384 (miR-384). Furthermore, LINC00491 and miR-384 were transfected into CAL-27 cells, while cell cycle was analyzed using flow cytometry. Cell proliferation was determined by methyl thiazolyl diphenyl-tetrazolium (MTT) assay. Cell migration and invasion were evaluated using Transwell experiments. The relationship between LINC00491 and miR-384 was confirmed using double luciferase reporting assay, while protein expression levels of P21, Ki67, E- cadherin, N-cadherin, and vimentin were assayed with Western blotting.&#x0D; Results: The expression of LINC00491 increased in TSCC tissues (p &lt; 0.05). The proportion of cells in G1-phase increased, while the proportion of cells in S-phase decreased (p &lt; 0.05). There was decrease in cell survival, cell migration and cell invasion (p &lt; 0.05). The protein expression levels of Ki67, N- cadherin, and vimentin were lowered, while those of P21, E-cadherin protein were increased (p &lt; 0.05). Transfection of LINC00491 and miR- 384 reduced the proportion of cells in G1 phase, but increased the proportion of cells in S-phase (p &lt; 0.05). Moreover, cell survival, migration and invasion were increased. The protein expressions of Ki67, N-cadherin, and vimentin rose, while those of P21 and E-cadherin decreased (p &lt; 0.05).&#x0D; Conclusion: LINC00491 promotes the proliferation, migration and invasion of TSCC cells by inhibiting miR-384. This finding provides a potential target for the treatment of TSCC.&#x0D; &#x0D; &#x0D; &#x0D;

Berberine regulates mesangial cell proliferation and cell cycle to attenuate diabetic nephropathy through the PI3K/Akt/AS160/GLUT1 signalling pathway.

High glucose (HG) is one of the basic factors of diabetic nephropathy (DN), which leads to high morbidity and disability. During DN, the expression of glomerular glucose transporter 1 (GLUT1) increases, but the relationship between HG and GLUT1 is unclear. Glomerular mesangial cells (GMCs) have multiple roles in HG‐induced DN. Here, we report prominent glomerular dysfunction, especially GMC abnormalities, in DN mice, which is closely related to GLUT1 alteration. In vivo studies have shown that BBR can alleviate pathological changes and abnormal renal function indicators of DN mice. In vitro, BBR (30, 60 and 90 μmol/L) not only increased the proportion of G1 phase cells but also reduced the proportion of S phase cells under HG conditions at different times. BBR (60 μmol/L) significantly reduced the expression of PI3K‐p85, p‐Akt, p‐AS160, membrane‐bound GLUT1 and cyclin D1, but had almost no effect on total protein. Furthermore, BBR significantly declined the glucose uptake and retarded cyclin D1‐mediated GMC cell cycle arrest in the G1 phase. This study demonstrated that BBR can inhibit the development of DN, which may be due to BBR inhibiting the PI3K/Akt/AS160/GLUT1 signalling pathway to regulate HG‐induced abnormal GMC proliferation and the cell cycle, supporting BBR as a potential therapeutic drug for DN.

Downregulation of long noncoding RNA T1NCR inhibits cell proliferation, invasion, and epithelial-mesenchymal transition of hepatocellular carcinoma

Accumulating reports have identified that long non-coding RNAs (IncRNAs) function as key regulators of tumor initiation and progression. The aim of the current study was to determine the clinical significance and functional role of TINCR in hepatocellular carcinoma (HCC). In the present study, the level of IncRNA TINCR expression was significantly upregulated in HCC tissues compared to adjacent normal tissues. Higher levels of IncRNA TINCR expression were significantly correlated with tumor size and vascular invasion of HCC patients. LncRNA TINCR knockdown inhibited cell proliferation ability, increased the proportion of G1 phase cells, reduced the proportion of S phase cells, and suppressed cell invasion of HCC in vitro. Additionally, IncRNA TINCR knockdown inhibited the HCC cell epithelial-mesenchymal transition (EMT) phenomenon by upregulating E-cadherin and reducing N-cadherin expression. We demonstrated that knockdown of IncRNA reduced tumor growth in vivo. Thus, these results indicated that IncRNA TINCR exhibits a tumor oncogenic role in HCC and inhibition of IncRNA TINCR might serve as a therapeutic target for HCC.

MiR-30a attenuates drug sensitivity to 5-FU by modulating cell proliferation possibly by downregulating cyclin E2 in oral squamous cell carcinoma

We aimed to determine the functional role of the miRNA, which affects drug sensitivity to 5-FU in oral squamous cell carcinoma (OSCC), using two types of 5-FU-resistant and parental OSCC cell lines. MiRNA microarray data showed that miR-30a was significantly upregulated in two resistant cell lines. Therefore, we investigated the effects and molecular mechanism of miR-30a on 5-FU sensitivity. Stable overexpression of miR-30a in parental OSCC cells decreased cell proliferation and attenuated drug sensitivity to 5-FU. Cell cycle analysis indicated that miR-30a overexpression increased the proportion of G1 phase cells and decreased the proportion of S phase cells. MiR-30a knockdown using siRNA reversed the effects of miR-30a overexpression. DNA microarray analysis using miR-30a-overexpressing cell lines and a TargetScan database search showed that cyclin E2 (CCNE2) is a target of miR-30a. A luciferase reporter assay confirmed that a miR-30a mimic interacted with the specific binding site in the 3' UTR of CCNE2. CCNE2 knockdown with siRNA in OSCC cells yielded decreased drug sensitivity to 5-FU, similar to miR-30a overexpressing cells. These findings suggest that miR-30a in OSCC may be a novel biomarker of 5-FU-resistant tumors, as well as a therapeutic target for combating resistance.

A Novel Biochemical Study of Anti-Dermal Fibroblast Replicative Senescence Potential of Panax Notoginseng Oligosaccharides.

Dermal fibroblast replicative senescence that often occurs in aging skin is characterized by loss of cell proliferative capacity, cell cycle arrest, decreased cell elongation, and decreased synthesis of dermal extracellular matrix (ECM) components. Although Panax notoginseng is known for its effectiveness in alleviating many age-related degenerative diseases, few studies have evaluated P. notoginseng components for efficacy or mechanisms of action in delaying cell replicative senescence. In this study, P. notoginseng oligosaccharides (PNO) were isolated using a stepwise purification procedure involving water extraction and alcohol precipitation followed by DEAE Sepharose Fast Flow column chromatography, preparative high performance liquid chromatography, and size-exclusion chromatography. Monosaccharides detected in PNO constituents included mannose, galactose, and sorbitose in relative molar proportions of 14.2:12.3:1, respectively, aligning with PNO absorption spectrum results resembling typical known spectra for sugars. In vitro, PNO treatment of replicative senescent NIH-3T3 fibroblasts significantly promoted cell vitality, inhibited SA-β-galactosidase (SA-β-Gal) activity, and reduced p16 and p21 protein-level expression. Moreover, PNO treatment of senescent fibroblasts led to a lower proportion of G1 phase cells and higher proportion of S phase cells, while also inducing aging NIH-3T3 cells to migrate and synthesize collagen-I (CoL-I). Mechanistically, PNO treatment up-regulated expression of proliferating cell nuclear antigen (PCNA), cyclin E, cyclin D1, and cyclin-dependent kinase 4 (CDK4) proteins and promoted phosphorylation of MEK, p38, and ERK1/2 to trigger cell cycle progression. Additionally, PNO treatment also up-regulated protein-level expression of TGF-β1 and levels of p-Smad2/3, p-FAK, and p-Pax to trigger CoL-I synthesis and cell migration. Taken together, these findings demonstrate that oligosaccharides purified from P. notoginseng could reverse fibroblast replicative senescence by promoting fibroblast cell proliferation, migration, and CoL-I production.

Cediranib Induces Apoptosis, G1 Phase Cell Cycle Arrest, and Autophagy in Non-Small-Cell Lung Cancer Cell A549 In Vitro.

Lung cancer remains the leading cause of cancer death worldwide. Late diagnosis, chemoresistance, and metastasis are the main reasons for the high mortality rate of lung cancer. Therefore, the development of other treatments is urgent. Cediranib (CED), a vascular endothelial growth factor receptor (VEGFR) kinase inhibitor, shows promising antitumour activities in various cancers including lung cancer. Here, we explored the effects and the underlying molecular mechanism of CED on non-small-cell lung cancer (NSCLC) cell line A549 cells in vitro. Our results show that CED could inhibit A549 cell proliferation and cloning formation. Meanwhile, G1 phase cell cycle arrest was also found, as featured by the increased proportion of G1 phase cells as well as the reduction of G1 phase relative proteins CDK4/cyclin D1 and CDK2/cyclin E. Moreover, the ratio of LC3-II/LC3-I was elevated significantly in CED-treated groups compared with the controls. Furthermore, the expression of p-Akt, p-P38, p-Erk1/2, and p-mTOR proteins was decreased obviously in the treatment groups. These results suggest that CED could induce apoptosis and G1 phase cell cycle arrest in A549 cells. Meanwhile, CED may induce autophagy through MAPK/Erk1/2 and Akt/mTOR signal pathway in A549 cells.

CDK4/6 inhibitor palbociclib overcomes acquired resistance to third-generation EGFR inhibitor osimertinib in non-small cell lung cancer (NSCLC).

BackgroundThe third‐generation EGFR‐TKI, represented by osimertinib, has been widely used in clinical practice; however, resistance eventually emerges. At present, it remains unclear whether an abnormal cell cycle is involved in acquired resistance, and whether the combination of palbociclib (CDK4/6 inhibitor) and osimertinib can overcome the third‐generation TKI resistance.MethodsWe established osimertinib‐resistant cells (H1975 OR) derived from EGFR‐mutant NSCLC cells H1975. Drug effects on cells were assessed with Cell Counting Kit‐8 (CCK8). Protein alterations were detected with western blot analysis. RT‐PCR was used to evaluate the differences of gene mRNA. Cell cycle distribution of H1975 S and H1975 OR cells was compared using flow cytometry.ResultsCompared with H1975, the sensitivity of H1975OR to the CDK4/6 inhibitor was increased and the proportion of cells in G1 phase was decreased. The mRNA level of CDK4, CDK 6 and the protein level of CDK4, pRB were increased in H1975OR. In the H1975OR cells, palbociclib significantly increased the proportion of G1 phase cells. The combination of osimertinib and palbociclib synergistically decreased the survival of H1975OR by cell cycle arrest. Combined treatment was found to inhibit the initial phosphorylation of RB by inhibiting the function of CDK4/6, significantly reducing the level of p‐RB, and blocking cell proliferation.ConclusionsAn osimertinib acquired resistance cell line (H1975 OR) was successfully established. The expression of cell cycle related genes was altered in H1975OR. The expression of CDK4 and the phosphorylation of Rb, the downstream molecule of CDK4/6, was increased in H1975OR cells. The combination of CDK4/6 inhibitor palbociclib and osimertinib could overcome the acquired resistance of osimertinib.

2-Epi-anthracimycin, a new cytotoxic agent from the marine-derived actinomycete Streptomyces sp. OPMA00631.

A new cytotoxic agent designated as 2-epi-anthracimycin (1) was isolated along with anthracimycin and anthracimycin B (2-demethylanthracimycin) from the culture broth of the marine-derived actinomycete Streptomyces sp. OPMA00631. The structure of 1 was elucidated based on spectroscopic analyses (1D and 2D NMR data and ROESY correlations). Compound 1 exhibited cytotoxicity against Jurkat cells with an IC50 value of 50.5 μM in 20 h. The effect of 1 on the cell cycle distribution of Jurkat cells was investigated. Compound 1 (7.80 μM) increased G1 phase cells from 51.1 to 62.0% and conversely, decreased G2 and M phase cells from 30.7 to 19.3 % in 20 h. At a higher concentration, 1 (250 μM) markedly increased subG1 phase cells (1.9% at 0 h to 16.5% at 20 h), while the proportion of G1 phase cells was maintained (62.3%). These results suggest that 1 exhibits cytotoxicity against Jurkat cells by arresting the cell cycle at the G1 phase.

Overexpression of the immediate early response 5 gene increases the radiosensitivity of HeLa cells.

The effects of the immediate early response 5 (IER5) gene on the sensitivity of HeLa cells to radiation remain unclear. In the present study, stably transfected HeLa cells resulting in the knockdown or overexpression of IER5 were investigated. In addition, xenografts of normal, IER5-silenced and -overexpressed HeLa cells were injected into nude mice and examined. The results demonstrated that the radiosensitivity of the IER5-overexpressed HeLa cells was significantly increased compared with that of the normal and IER5-silenced cells. The upregulation of IER5 effectively decreased cell proliferation and IER5 silencing promoted cell proliferation compared with that in the normal HeLa cells. Following irradiation of the cells with IER5 knockdown, cell cycle was arrested at the G2/M phase and an increase in the proportion of S phase cells was observed. By contrast, the overexpression of IER5 led to an increase in the proportion of G1 phase cells. Furthermore, the upregulation of IER5 inhibited tumor growth in vivo. The present findings demonstrate that the IER5 gene affects the radiosensitivity of HeLa cells and serves an important role in cell proliferation, suggesting that this gene may be a potential radiotherapeutic target in cervical cancer.

Ribosomal Protein S9 Expression in Multiple Myeloma and Its Effect on Cell Biological Function

Objective To identify the expression of ribosomal protein S9(RPS9)in multiple myeloma(MM)and explore its effect on the biological characteristics of myeloma cells and the corresponding mechanisms. Methods Bone marrow mononuclear cells were harvested in 10 healthy volunteers(CON group)and bone marrow CD138 +cells from 30 MM patients(CD138+group).Quantitative polymerase chain reaction(qPCR)was performed to detect RPS9 expression at mRNA level.In three cases from CON group and 11 cases from CD138+group,Western blot was performed to detect RPS9 at protein level.GSE19784 dataset was employed to detect the relationships of RPS9 expression with the overall survival rate,nuclear factor-κB(NF-κB),small ubiquitin-like modifier(SUMO),and ubiquitin pathway.After the RPS9 knock-down vector was constructed,flow cytometry was performed to detect the infection efficiency and qPCR and Western blot to detect the knock-down efficiency.RPMI8226 was divided into CON group and RPS9-short hairpin RNA(shRNA)group,in which annexin V allophycocyanin/propidium iodide(PI)double staining was performed to detect the change of apoptosis,CCK8 to detect the proliferation change,and PI staining to detect cell cycle change.After sentrin-specific protease 1(SENP1)overexpression vector was constructed,Western blot was performed to detect the phosphorylation of P65 and inhibitory subunit-κBα(IκBα)from NF-κB pathway in CON,RPS9-shRNA,and RPS9-shRNA-SENP1 cells;in addition,annexin V/PI double staining was also performed to detect the apoptosis in these three cells. Results The relative expression of RPS9 in CON group and CD138+group was(1.00±0.12)and(5.45±0.71),respectively(t=4.291,P=0.0036).Western blot showed RPS9 expression was high in most myeloma CD138+cells.The high expression of RPS9 was associated with both extramedullary invasion and overall survival in GSE19784 dataset.After RPMI8226 was infected with CON or RPS9-shRNA lentivirus for 48 hours,flow cytometry confirmed that the infection efficiencies were above 90% in both groups.qPCR and Western blot confirmed that RPS9 expression was inhibited at both mRNA and protein levels.After RPMI8226 CON and RPS9-shRNA infected with virus for 48 hours,the proportion of annexin V-positive cells in CON and RPS9-shRNA cells was(3.47±0.37)% and(18.60±64.00)%(t=9.015,P=0.0008).The proliferation index significantly differed between CON group and RPS9-shRNA group at 72 hours(t=6.846,P=0.0024).When CON and RPS9-shRNA were infected with virus for 48 hours,the proportion of G2 phase cells was(29.28±3.42)% and(10.43±1.43)%,respectively(t=9.329,P=0.0007).The RPS9 expression was positively correlated with SENP1 in GSE19784 dataset and negatively correlated with IκBα coding gene NFKBIA.Western blot further confirmed that RPS9 knockdown inhibited the expression of SENP1,inhibited the phosphorylation of NF-κB subunit P65 and inhibitor IκBα,and promoted the expression of IκBα.Overexpression of SENP1 not only impeded this effect but also reduced RPS9-induced apoptosis. Conclusions RPS9 is highly expressed in MM CD138+cells and is associated with overall survival and extramedullary infiltration.Inhibition of RPS9 can promote apoptosis,cell cycle arrest,and proliferation of myeloma cells.RPS9 can affect the activation of NF-κB pathway and cell apoptosis through SENP1,suggesting that SENP1 may be a key factor in the biological effect of RPS9.

Transient Telomerase Inhibition with Imetelstat Impacts DNA Damage Signals and Cell-Cycle Kinetics.

Telomerase is the ribonucleoprotein reverse transcriptase that catalyzes the synthesis of telomeres at the ends of linear chromosomes and contributes to proper telomere-loop (T-loop) formation. Formation of the T-loop, an obligate step before cell division can proceed, requires the generation of a 3'-overhang on the G-rich strand of telomeric DNA via telomerase or C-strand specific nucleases. Here, it is discovered that telomerase activity is critical for efficient cell-cycle progression using transient chemical inhibition by the telomerase inhibitor, imetelstat. Telomerase inhibition changed cell cycle kinetics and increased the proportion of cells in G2-phase, suggesting delayed clearance through this checkpoint. Investigating the possible contribution of unstructured telomere ends to these cell-cycle distribution changes, it was observed that imetelstat treatment induced γH2AX DNA damage foci in a subset of telomerase-positive cells but not telomerase-negative primary human fibroblasts. Chromatin-immunoprecipitation with γH2AX antibodies demonstrated imetelstat treatment-dependent enrichment of this DNA damage marker at telomeres. Notably, the effects of telomerase inhibition on cell cycle profile alterations were abrogated by pharmacological inhibition of the DNA-damage-repair transducer, ATM. Also, imetelstat potentiation of etoposide, a DNA-damaging drug that acts preferentially during S-G2 phases of the cell cycle, depends on functional ATM signaling. Thus, telomerase inhibition delays the removal of ATM-dependent DNA damage signals from telomeres in telomerase-positive cancer cells and interferes with cell cycle progression through G2Implications: This study demonstrates that telomerase activity directly facilitates the progression of the cell cycle through modulation of transient telomere dysfunction signals. Mol Cancer Res; 16(8); 1215-25. ©2018 AACR.

Brain type glycogen phosphorylase small interfering RNA inhibits proliferation of human osteosarcoma cell lines

Objective To observe the effect of brain type glycogen phosphorylase (PYGB) small interfering RNA (siRNA) on proliferation, apoptosis, distribution of cell cycle in human osteosarcoma cell line MG63 with significant expression level of PYGB. Methods Thirty-five samples of osteosarcoma and 15 samples of bone cysts were detected for the PYGB expression level using real-time quantitative polymerase chain reaction(Real-time PCR). Western blotting was used to select osteosarcoma cell lines with high expression level of PYGB. MG63 cells were taken out for the following study. Cell counting kit-8 (CCK-8) assay was preformed to evaluate the cell proliferation. Cell apoptosis and cell cycle of MG63 cells were identified using flow cytometry. Besides, cell invasion and migration were evaluated by Transwell assay. In addition, cell apoptosis and metastasis related proteins B cell lymphoma/leukemia-2 associated X protein (bax), B cell lymphoma/leukemia-2 (bcl-2) were measured by Western blotting. Results Expression of PYGB exhibited a higher level in osteosarcoma samples (0.105±0.945) than that in bone cyst (0.062±0.038, P=0.006). The cell proliferation of MG63 cells were inhibited by PYGB siRNA. PYGB knockdown in MG63 cells increased the proportion of G1 phase cells from (49.74±1.54)% to (69.41±2.35)% (P=0.004), while decreased the proportion of S phase cells from (21.04±2.59)% to (14.15±0.98)% (P=0.028) and decreased the proportion of G2 phase cells from (25.62±0.64)% to (8.19±0.11)% (P=0.002). The expression of bax significantly reduced in PYGB siRNA group while the expression of bcl-2 significantly reduced in PYGB siRNA group. Low expression of PYGB reduced G1 phase of the cell cycle transition. Conclusion PYGB siRNA inhibited proliferation of MG63 cells by targeting cysteinyl aspartate-specific protease/bcl and cyclin-dependent kinase (CDK)1 signaling pathway. Key words: Brain type glycogen phosphorylase; Small interfering RNA; Osteosarcoma; Cell cycle

Flavanol-Rich Lychee Fruit Extract Prevents Diabetes-induced Muscle Loss And Palmitate-induced Myotube Loss

Diabetes-induced muscle loss is associated with stimulated the muscle RING-finger protein 1 (MuRF1), a muscle specific E3 ubiquitin ligase. Elevated lipid metabolites impair myogenesis. Flavanol-rich lychee fruit extract (FRLFE) exhibited anti-diabetic and -obesity properties which would be an alternative approach for maintaining muscle homeostasis. PURPOSE: The underlying mechanisms of FRLFE on maintaining muscle homeostasis was studied in vivo and in vitro. METHODS: Dietary (10 wk) FRLFE supplementation (200 mg/kg diet) on the skeletal muscle size and transcription factors such as NF-κB and Foxo3a involved in regulation of MuRF1 were investigated in diabetic db/db mice (n=10/per group). The roles of FRLFE on cell cycle and senescent phenotype were investigated in palmitate-induced insulin resistance in C2C12 muscle cells. The statistical significance of the differences among the groups (P < 0.05) was determined by one-way ANOVA and following post hoc assessment by Student-Newman-Keuls Method. RESULTS: The average cross-sectional area was significantly increased by 1.6-fold after administration of FRLFE compared with non-treated db/db mice (420μm2). Prevention of muscle loss by FRLFE was associated with down regulation of MuRF1 mRNA expression (410% vs. 100%, p<0.05). Decreased NF-κB expression in the nuclear fraction was observed in FRLFE treated db/db mice compared with untreated mice (260% vs. 60%, p<0.05). At transcriptional level, FRLFE abated ceramide-induced MuRF1 promoter activity (200% vs. 100%, p<0.05). Restoration of SIRT1 expression (30% vs. 150%, p<0.05) prevented Foxo3a nuclear localization in FRLFE treated db/db mice. A strong β-galactosidase staining positive signal was observed in the palmitate-treated myoblasts. For cell cycle analysis, significantly increased proportion of cells in G2-phase by palmitate was observed compared with group without palmitate treatment (28.9% vs. 18.3%). Weak β-galactosidase staining positive signals in accordance with decreased proportion of cells in G2-phase (21.7%) were observed in FRLFE-treated myoblasts. CONCLUSION: The efficacy of FRLFE on preserving skeletal muscle mass and myogenic process indicates that FRLFE acts as an effective supplement for diabetes and/or obesity-induced muscle atrophy.

Effect of triptolide on human oral cancer cell proliferation and PTEN gene mRNA expression in oral cancer

Objective: To investigate the effect of triptolide on human oral cancer cell (HB) proliferation and phosphates and tensin homologue deleted on chromosome ten gene (PTEN) mRNA expression in oral cancer. Methods: The cancer cells were cultured in the medium containing triptolide of different concentrations for 24, 48 and 72 h. Methyl thiazolyl tetrazolium (MTT) method was used to test the rate of growth inhibition of cancer cells, flow cytometer to detect the change of cell cycle and reveres transcription-PCR (RT-PCR) to examine the expression of PTEN mRNA. The expression of PTEN protein was examined by Western blotting. Results: The rate of growth inhibition was (26.92 ± 0.14)%, (38.67 ± 0.11)%, (72.62 ± 0.89)% and (90.42 ± 0.28)%, respectively. The corresponding expression of PTEN mRNA was (3.59±0.21)%, (5.27±0.40)%, (7.18±0.44)% and (9.16±0.50)%, respectively and the corresponding A value of PTEN protein was 0.135±0.007, 0.410±0.020, 0.447±0.017 and 0.884±0.066, respectively. The proportion of G1 phase cells increased from (58.78±0.98)% to (84.13±0.47)%, but the proportion of S phase cells decreased from (25.40±0.43)% to (9.41±0.73)%. Conclusions: The triptolide not only had inhibitory effect on the HB proliferation, but also affected the cell cycle.