Cell Cycle-related Proteins Research Articles

Antitumor Activity of Small Activating RNAs Induced PAWR Gene Activation in Human Bladder Cancer Cells.

Small double-stranded RNAs (dsRNAs) have been proved to effectively up-regulate the expression of particular genes by targeting their promoters. These small dsRNAs were also termed small activating RNAs (saRNAs). We previously reported that several small double-stranded RNAs (dsRNAs) targeting the PRKC apoptosis WT1 regulator (PAWR) promoter can up-regulate PAWR gene expression effectively in human cancer cells. The present study was conducted to evaluate the antitumor potential of PAWR gene induction by these saRNAs in bladder cancer. Promisingly, we found that up-regulation of PAWR by saRNA inhibited the growth of bladder cancer cells by inducing cell apoptosis and cell cycle arrest which was related to inhibition of anti‑apoptotic protein Bcl-2 and inactivation of the NF-κB and Akt pathways. The activation of the caspase cascade and the regulation of cell cycle related proteins also supported the efficacy of the treatment. Moreover, our study also showed that these saRNAs cooperated with cisplatin in the inhibition of bladder cancer cells. Overall, these data suggest that activation of PAWR by saRNA may have a therapeutic benefit for bladder cancer.

β-TrCP1 facilitates cell cycle checkpoint activation, DNA repair, and cell survival through ablation of β-TrCP2 in response to genotoxic stress

F-box proteins β-TrCP1 and β-TrCP2 are paralogs present in the human genome. They control several cellular processes including cell cycle and DNA damage signaling. Moreover, it is reported that they facilitate DNA damage-induced accumulation of p53 by directing proteasomal degradation of MDM2, a protein that promotes p53 degradation. However, the individual roles of β-TrCP1 and β-TrCP2 in the genotoxic stress-induced activation of cell cycle checkpoints and DNA damage repair remain largely unknown. Here, using biochemical, molecular biology, flow cytometric, and immunofluorescence techniques, we show that β-TrCP1 and β-TrCP2 communicate during genotoxic stress. We found that expression levels of β-TrCP1 are significantly increased while levels of β-TrCP2 are markedly decreased upon induction of genotoxic stress. Further, our results revealed that DNA damage-induced activation of ATM kinase plays an important role in maintaining the reciprocal expression levels of β-TrCP1 and β-TrCP2 via the phosphorylation of β-TrCP1 at Ser158. Phosphorylated β-TrCP1 potently promotes the proteasomal degradation of β-TrCP2 and MDM2, resulting in the activation of p53. Additionally, β-TrCP1 impedes MDM2 accumulation via abrogation of its lysine 63-linked polyubiquitination by β-TrCP2. Thus, β-TrCP1 helps to arrest cells at the G2/M phase of the cell cycle and promotes DNA repair upon DNA damage through attenuation of β-TrCP2. Collectively, our findings elucidate an intriguing posttranslational regulatory mechanism of these two paralogs under genotoxic stress and revealed β-TrCP1 as a key player in maintaining the genome integrity through the attenuation of β-TrCP2 levels in response to genotoxic stress.

RBBP6 interactome: RBBP6 isoform 3/DWNN and Nek6 interaction is critical for cell cycle regulation and may play a role in carcinogenesis

Abstract RBBP6 is a multidomain protein, with four splice variants translated into four functional isoforms. RBBP6 isoform 1 has been reported to interact with TP53 and pRb as well as with proteins that regulate transcriptional response to tumorigenesis such as HDM2, ZBTB38, YBX1 and NEK6. Experimental validation of isoforms 2 and 4 is yet to be conducted. The third isoform, consisting of only the DWNN domain and a short unordered c terminus, has been shown to be down-regulated in several human cancers and demonstrated as a regulator of G2/M cell cycle arrest. A number of studies have supported the role of DWNN in cell cycle regulation, however, its mechanism in these processes remains obscure. Posttranslational modification of DWNN could be critical for its function and this study was formulated to understand how the DWNN regulates the cell cycle. Our study identified 12 cell cycle-related proteins interacting with DWNN using various bioinformatics tools. We also identified 10 ubiquitin ligases that interact with DWNN. The most relevant interacting partner, the cell cycle regulator Nek6, has been reported to interact with DWNN during the cell cycle. It was therefore critical to interrogate the interaction between Nek6 and DWNN by homology modelling and docking. The DWNN mutants had a reduced affinity for NEK6 with at least one of the mutants having changes that affect at least one phosphorylation site. It is likely that NEK6 promotes cell proliferation by phosphorylating DWNN. This work suggests that DWNN co-regulates RNA splicing, ubiquitination, and cell cycle control. DWNN may therefore, be targeted for novel anticancer therapies through cell cycle regulation.

Ferulic acid-mediated modulation of apoptotic signaling pathways in cancer.

Ferulic acid (4-hydroxy-3-methoxycinnamic acid, FA), a hydroxycinnamic acid derived from various seeds, nuts, leaves, and fruits, exists in a free form as well as is covalently conjugated with polysaccharides, glycoproteins, polyamines, lignin, and hydroxy fatty acids of plant cell walls. It exhibits a variety of pharmacological effects, such as antioxidant, anti-inflammatory, vasodilatory, antithrombotic, antimicrobial, anti-allergic, antiviral, hepatoprotective, and anticancer activities. FA induces the expression of cell cycle-related proteins, such as p53 and p21, and reduces cyclin D1 and cyclin E levels. Moreover, FA triggers apoptosis and autophagic cell death depending on intracellular reactive oxygen species production in various cancer cell lines. The potential apoptotic action of FA is mediated by altered expression of procaspase-3, procaspase-8, procaspase-9, poly (ADP ribose) polymerase, Bcl-2, and Bax. It blocks the activation of both the canonical Smad and noncanonical extracellular-signal-regulated kinase/Akt (protein kinase B) pathways in various cancer cells. However, due to low solubility and permeability, its availability to biological systems is limited. Therefore, encapsulation of FA into chitosan tripolyphosphate nanoparticles may enhance its cytocompatibility, solubility, and anticancer potential. The nanohybrids of FA and double layered hydroxide exhibit cellular delivery properties of intercalated molecules on cancer cell lines. This chapter summarizes the anticancer efficacy of FA with an emphasis on the role of apoptosis, and underlying molecular mechanisms involving various signaling pathways in tumor cells.

Anticancer Activity of Fucoidan via Apoptosis and Cell Cycle Arrest on Cholangiocarcinoma Cell.

Objective:Many previous studies reported that fucoidan has antitumor activities. The objective of the present study was to determine the cytotoxic effects and related mechanisms of cell death induced by fucoidan extracted from Fucus vesiculosus on CL-6 cholangiocarcinoma cell. Methods:CL-6 and OUMS cells were treated with 0, 100, 200, and 300 μg/mL of fucoidan. MTT assay was used to determine cytotoxicity. Flow cytometry-based assay was used to examine the distribution of apoptosis and cell cycle. The changes in nuclear morphology were determined using Hoechst 33,342 staining. Mitochondrial membrane potential (ΔΨm) was evaluated using the JC-1 kit. The apoptotic, anti-apoptotic, and cell cycle-related proteins study were examined by Western blot analysis. Results:The relative viable cell number of treated CL-6 cells was decreased but no effect was observed in OUMS normal cells. Furthermore, treated cells were arrested in the G0/G1 phase with down-regulation of cyclin D1 and CDK4. Annexin V/PI staining with flow cytometry analysis suggested that fucoidan could induce apoptosis in CL-6 cells. Western blot study revealed the up-regulation of apoptotic markers including Bax, cleaved PARP, cleaved caspase-3, but down-regulation of anti-apoptotic markers, cl-2. Moreover, fucoidan could induce nuclear fragmentation and chromatin condensation with alteration of ΔΨm. Conclusion:Fucoidan exerts antitumor properties against CL-6 cholangiocarcinoma cells illustrated by the induction of apoptosis and cell cycle arrest.

Aspirin inhibits cholangiocarcinoma cell proliferation via cell cycle arrest invitro and invivo.

Cholangiocarcinoma is the most common biliary duct malignancy and the second most common primary liver cancer, accounting for 10-20% of hepatic malignancies. With high mortality and poor prognosis, the 5-year survival rate of cholangiocarcinoma is only 10%. A previous study demonstrated a significant association between aspirin use and a decreased risk of cholangiocarcinoma. However, the effect of aspirin on cholangiocarcinoma remains unknown. Therefore, the aim of the present study was to investigate the effects of aspirin on cholangiocarcinoma in vitro and in vivo. Three cholangiocarcinoma cell lines were used to analyze the effect of aspirin on cell proliferation, cell cycle progression, apoptosis, and the regulation of microRNAs. MicroRNAs are known to regulate the development and progression of various types of cancer. An HuCCT-1 xenograft model was used for the in vivo study. It was determined that aspirin inhibited the proliferation of human cholangiocarcinoma cells (except TKKK cells). Aspirin induced cell cycle arrest in the G0/G1 phase and regulated cell-cycle related proteins in cholangiocarcinoma cells (HuCCT-1 cells) but did not induce apoptosis. The expression of miR-340-5p was significantly upregulated after treatment, and overexpression of miR-340-5p inhibited the proliferation of HuCCT-1 cells and decreased the levels of cyclin D1. TKKK cells had low miR-340-5p expression, which may explain why aspirin had no effect on their proliferation. In vivo, aspirin reduced the growth of xenografted tumors. In conclusion, the present study indicated that aspirin partially inhibited cholangiocarcinoma cell proliferation and tumor growth by inducing G0/G1 phase cell cycle arrest, potentially through the miR-340-5p/cyclin D1 axis.

Garcinol inhibits the proliferation of endometrial cancer cells by inducing cell cycle arrest.

Endometrial cancer (EC) is the most common gynecological cancer, and one of the most important causes of cancer-related deaths in women worldwide. The long-term survival rate is lower in advanced-stage and recurrent EC, therefore it is important to identify new anticancer drugs. Garcinol, a polyisoprenylated benzophenone, is a promising anticancer drug for various cancer types but its effects on EC remain unclear. To investigate the anticancer effects of garcinol on EC, cell proliferation and cell cycle were assessed by real-time cell proliferation, cell counting, and colony formation assays, flow cytometric analysis, and 5-ethynyl-2′-deoxyuridine (EdU) incorporation assay, in EC Ishikawa (ISH) and HEC-1B cell lines. Western blotting was used to evaluate the expression of cell cycle-related protein cyclins, cyclin-dependent kinase and tumor suppression proteins. Garcinol inhibited ISH and HEC-1B cell proliferation in a dose-dependent manner, and induced ISH and HEC-1B cell cycle arrest at the G1 phase and G2/M phase, respectively, and decreased the S phase and DNA synthesis in these two cell lines. Following garcinol treatment the expression levels of p53 and p21 were increased, while the expression levels of CDK2, CDK4, cyclin D1 and cyclin B1 were gradually decreased in a dose-dependent manner in both ISH and HEC-1B cells. In addition, the expression levels of phosphorylated c-JUN N-terminal kinase (JNK) and p-c-JUN were significantly increased in both types of cells. Collectively, garcinol can induce EC cell cycle arrest and may be a promising candidate for EC chemotherapy.

Chaetoglobosin G inhibits proliferation, autophagy and cell cycle of lung cancer cells through EGFR/MEK/ERK signaling pathway.

Chaetoglobosin G (CG) is a fungal secondary metabolite and shows anti-tumor effects. However, the mechanisms behind the anti-tumor effect is still unclear. In this study, we evaluated the anti-proliferation effect of CG on human NSCLC A549 cells and explored the underlying mechanisms. The anti-proliferation effect of CG on A549 cells was evaluated by MTT. The targets of CG were screened through transcriptome sequencing. A flow cytometer was used to detect cell cycle and apoptosis. Western blotting was used to analyze apoptosis, cell cycle and autophagy related protein expression. Our results showed that CG had a dose-dependent inhibitory effect on proliferation of A549 cells. Transcriptome sequencing analysis found that CG obviously induced cell cycle arrest. Flow cytometry analysis and western blot showed that CG induced G2/M arrest with p21 protein upregulation and cyclinB1 protein downregulation. Western blot analysis also indicated that p-EGFR, EGFR, p-MEk and p-ERK protein expressions decreased and autophagy protein LC3II expression increased, indicating that CG can promote autophagy through EGFR/MEK/ERK/LC3 pathway. Moreover, CG can induce apoptosis with bcl-2 protein decrease. In conclusion, this study indicated that CG obviously inhibited A549 cell proliferation, and its mechanism may induce autophagy of A549 cells through EGFR/MEK/ERK/LC3 pathway to upregulate the expression of P21, thus lead to G2/M phase arrest to exert an anti-tumor role.

Knockdown of SALL4 inhibits the proliferation, migration, and invasion of human lung cancer cells in vivo and in vitro.

BackgroundThis study aimed to investigate the SALL4 expression in lung cancer, determine if SALL4 regulates the biological functions of lung cancer cells at the cellular level, and clarify the possible mechanisms involved.MethodsImmunohistochemistry was used to detect the SALL4 expression messenger RNA (mRNA) in 62 cases of lung cancer tissue microarray. The correlation of SALL4 with the clinical pathological parameters and overall life cycle of patients and the impact of disease-free life cycle was analyzed. Reverse transcription-polymerase chain reaction (RT-PCR) and western blotting were used to detect the SALL4 expression in lung cancer cell lines and nude mouse models. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay, colony-forming assay, and flow cytometry were used to detect the effects of interference with SALL4 expression on lung cancer cell proliferation and transplant tumor models; the effect of interference with SALL4 expression on the growth of transplanted tumors in vivo was also examined.ResultsSALL4 was highly expressed in lung cancer tissues and cell lines and was closely related to the patient’s TNM stage and lymph node metastasis. Compared to patients with a high SALL4 expression, those with a lower SALL4 expression had a longer overall and disease-free survival. The expression of SALL4 is an independent risk factor for the prognosis of lung cancer patients. Interference with SALL4 expression can significantly inhibit cell proliferation and clonal formation. Interfering with the expression of SALL4 can arrest the cells in the G0/G1 phase by inhibiting the expression of the cell cycle–related proteins, cyclin B, cyclin E, and cyclin D1. Furthermore, wound-healing and Transwell assays showed that interference with SALL4 expression could significantly inhibit the migration and invasion of lung cancer cells, while experiments in nude mice showed that interference with SALL4 expression could significantly inhibit the size and weight of transplanted tumors.ConclusionsSALL4 was highly expressed in lung cancer cell lines. Interference with the expression of SALL4 can effectively inhibit the proliferation, migration and invasion of lung cancer cells, promote cell cycle arrest, and play the function of tumor suppressor genes. SALL4 may be a new target for the diagnosis and treatment of lung cancer.

Grape Seed Proanthocyanidins Induce Apoptosis and Cell Cycle Arrest of HepG2 Cells Accompanied by Induction of the MAPK Pathway and NAG-1.

Hepatocellular carcinoma (HCC) is one of the common malignancies leading to death. Although radiotherapy and chemotherapy have certain effects, their side effects limit their therapeutic effect. Phytochemicals have recently been given more attention as promising resources for cancer chemoprevention or chemotherapy due to their safety. In this study, the effects of grape seed proanthocyanidins (GSPs) on the apoptosis, cell cycle, and mitogen-activated protein kinase (MAPK) pathway-related proteins and non-steroidal anti-inflammatory drug-activated gene-1 (NAG-1) expression of HepG2 cells were investigated. The results showed that GSPs inhibited the viability of HepG2 cells in a time- and dose-dependent manner, induced apoptosis and G2/M phase cell cycle arrest, and regulated cell cycle-related proteins, cyclin B1, cyclin-dependent kinase 1, and p21. GSPs also increased reactive oxygen species production and caspase-3 activity. In addition, GSPs also increased the expression of p-ERK, p-JNK, p-p38 MAPK and NAG-1, and GSPs-induced NAG-1 expression was related to the MAPK pathway-related proteins. These data suggest that GSPs may be promising phytochemicals for HCC chemoprevention or chemotherapy.

Histone methyltransferase SETD2 inhibits tumor growth via suppressing CXCL1-mediated activation of cell cycle in lung adenocarcinoma.

The histone H3 lysine 36 methyltransferase SET-domain-containing 2 (SETD2) has been reported to be frequently mutated or deleted in many types of human cancer. However, the role of SETD2 in lung adenocarcinoma (LUAD) has not been well documented. In the present study, we found that SETD2 was significantly down-regulated both in LUAD tissues and cell lines. Functionally, the increased expression of SETD2 significantly attenuated the proliferation of cancer cells by affecting the cell cycle, whereas SETD2 deficiency dramatically improved these proliferative abilities of cancer cells. Through conjoint analysis of RNA-seq and ChIP data, we identified a functional target gene of SETD2, CXCL1, and its expression was negatively correlated with that of SETD2. Moreover, SETD2 deletion stimulated cell cycle-related proteins to promote LUAD. Further mechanistic studies demonstrated that histone H3 lysine 36 trimethylation (H3K36me3) catalyzed by SETD2 interacted with the promoter of CXCL1 to regulate its transcription and downstream signaling pathways, contributing to tumorigenesis in vitro and in vivo. Our findings suggested that SETD2 inhibited tumor growth via suppressing CXCL1-mediated activation of cell cycle, indicating that the regulation of H3K36me3 level by targeting SETD2 and/or the administration of downstream CXCL1 might represent a potential therapeutic way for new treatment in LUAD.

Deletion of Golgi protein 73 delayed hepatocyte proliferation of mouse in the early stages of liver regeneration.

Golgi protein 73 (GP73) is a transmembrane protein that can promote the proliferation of cancer cells. However, the roles of GP73 in the proliferation of non-malignant hepatocytes have rarely been investigated. The wild-type (GP73+/+ ) and GP73 gene knockout mice (GP73-/- ) were subject to 70% partial hepatectomy (PHx) to explore the involvement of GP73 in liver regeneration. After PHx, a significant increase of GP73 expression was observed in GP73+/+ mouse liver. Noticeably, promoted recovery of liver mass was observed in GP73-/- mouse at Day 1 after PHx, as showed by the liver/body weight ratio. RNA sequencing revealed that genes relevant to cell cycle and inflammation response in the residual liver tissues were severely suppressed with the deletion of GP73, particularly the inactivation of NF-κB signal pathway in early phase of liver regeneration. In line with this, we do see the downregulation of cell cycle-related protein including cyclin D1, p-cyclin D1, β-catenin, as well as interleukin 6, tumor necrosis factor-α, CCl2, and CXCl10. In contrast, activation of mTOR signaling pathway was documented, accompanied with the histological hypertrophy of hepatocytes in GP73-/- mouse. Golgi protein 73 deletion leads to delayed response of liver regeneration and inflammation in the early stages of liver regeneration after PHx.

LncRNA SUMO1P3 regulates the invasion, migration and cell cycle of gastric cancer cells through Wnt/β-catenin signaling pathway

Objective To investigate the regulatory effect of long non-coding RNA (lncRNA) SUMO1P3 on invasion, migration and cell cycle of gastric cancer (GC) cells through Wnt/β-catenin signaling pathway. Methods Tumor tissues and adjacent normal tissues from the GC patients were collected, and human normal gastric epithelial cells GES1 and GC cells SGC-7901, MKN45, HGC-27 and AGS were selected for study. The expression of SUMO1P3 in GC tissues and cells were detected by RT-qPCR. The effects of SUMO1P3 on the proliferation, invasion and migration of SGC-7901 and MKN45 cells were detected by CCK-8, transwell and wound healing assay respectively, and the effects of SUMO1P3 on apoptosis and cycle progression of SGC-7901 and MKN45 cells were detected by flow cytometry. The expressions of Wnt/β-catenin pathway-related and cell cycle-related proteins were detected by Western blot. Results The expression of SUMO1P3 was significantly upregulated in GC tissues and cell lines. Downregulation of SUMO1P3 significantly inhibited the SGC-7901 and MKN45 cell proliferation, invasion, migration, and cycle progression and promoted the cell apoptosis, while overexpression of SUMO1P3 showed the opposite effect. Further study showed that downregulation of SUMO1P3 significantly reduced the expressions of Wnt1, β-catenin, c-myc, and Cyclin D1 in SGC-7901 and MKN45 cells. Conclusion SUMO1P3 may promote invasion, migration, and cycle progression of SGC-7901 and MKN45 cells by enhancing the Wnt/β-catenin pathway.

Regulating DSC2 Expression Affects the Proliferation and Apoptosis of Prostate Cancer Cells.

BackgroundProstate cancer threatens the life and health of men in China. Desmocollin-2 (DSC2) is a member of DSC family, abnormal expression of which can affect the invasion and metastasis of tumor cells. The aim of this study was to investigate the role of DSC2 in prostate cancer.Materials and MethodsRegulating DSC2 expression in prostate cancer cells was conducted with transfection. The expression of DSC2, apoptosis-related proteins, cell cycle-related proteins and E-cadherin (E-cad)/β-catenin pathway was detected by Western blot analysis. The proliferation, clone formation ability, migration, invasion and apoptosis of transfected cells were in turn detected by cell counting kit-8 (CCK-8) assay, clone formation assay, wound healing assay, transwell assay and flow cytometry analysis.ResultsDSC2 expression was increased in prostate cancer cells compared with RWPE-1 cells. Inhibition of DSC2 promoted the proliferation, clone formation ability, migration and invasion while suppressed apoptosis of LNCaP cells and PC-3 cells. Inhibition of DSC2 affected the expression of apoptosis-related proteins and cell cycle-related proteins according to the changes of apoptosis and proliferation. Furthermore, inhibition of DSC2 up-regulated the expression of p-β-catenin and EGFR while down-regulated the expression of E-cad. DSC2 overexpression exerted the opposite effect of inhibition of DSC2 on LNCaP cells and PC-3 cells.ConclusionDSC2 expression was increased in prostate cancer cells. In addition, inhibition of DSC2 promoted the proliferation, clone formation ability, migration and invasion while suppressed apoptosis of LNCaP cells and PC-3 cells, which provided the fundamental basis for treatment of prostate cancer.

Effects of Cedrus atlantica extract on acute myeloid leukemia cell cycle distribution and apoptosis.

This study investigated the anti-leukemic effects of Cedrus atlantica extract (CAt extract) on cell cycle distribution and apoptosis in human acute myeloid leukemia (AML) cells. AML often occurs in older adults, accounting for 60% of the cases, and is likely to be resistant to chemotherapy due to multidrug resistance, resulting in early death during cancer treatment. With the increasing focus on prevention medicine, natural plant components are being used as a major source for the development of therapeutic drugs or functional foods to cure or alleviate the disease. Cedrus species are known to have anti-inflammatory, antimicrobial, antiviral, and anticancer effects; however, the anticancer effects of CAt extract have not been elucidated. In this study, CAt extract demonstrated an inhibitory effect on human leukemia cells in a concentration-dependent manner; CAt extract induced G0/G1 phase arrest via restrained protein levels of p-Rb and cell cycle-related proteins. After CAt extract exposure, the extrinsic and intrinsic apoptotic pathways were activated through caspase-8, -9, and -3 cleavage. Additionally, CAt extract suppressed VEGF, MMP-2, and MMP-9 expression. This study demonstrated that CAt extract treatment significantly reduced cell growth, cell cycle arrest in the G0/G1 phase, and induction of apoptosis, leading to leukemia cell death.

FAM188B Expression Is Critical for Cell Growth via FOXM1 Regulation in Lung Cancer

Although family with sequence similarity 188 member B (FAM188B) is known to be a member of a novel putative deubiquitinase family, its biological role has not been fully elucidated. Here, we demonstrate the oncogenic function of FAM188B via regulation of forkhead box M1 (FOXM1), another oncogenic transcription factor, in lung cancer cells. FAM188B knockdown induced the inhibition of cell growth along with the downregulation of mRNA and protein levels of FOXM1. FAM188B knockdown also resulted in downregulation of Survivin and cell cycle-related proteins, which are direct targets of FOXM1. Interestingly, FOXM1 co-immunoprecipitated with FAM188B, and the levels of FOXM1 ubiquitination increased with FAM188B knockdown but decreased with FAM188B overexpression. In addition, in vivo xenograft of FAM188B siRNA (siFAM188B) RNA-treated cells resulted in the retardation of tumor growth compared with that in the control. Furthermore, protein levels of FAM188B and FOXM1 were elevated in the human lung cancer tissues, and FAM188B expression was negatively correlated with the overall survival of lung cancer patients. These results indicate that FAM188B exerts its oncogenic effects by regulating FOXM1 deubiquitination and thus its stability. Therefore, FAM188B might be a potential therapeutic target to control lung cancer progression.

Simulated microgravity reduces proliferation and reorganizes the cytoskeleton of human umbilical cord mesenchymal stem cells.

The cytoskeleton plays a key role in cellular proliferation, cell-shape maintenance and internal cellular organization. Cells are highly sensitive to changes in microgravity, which can induce alterations in the distribution of the cytoskeletal and cell proliferation. This study aimed to assess the effects of simulated microgravity (SMG) on the proliferation and expression of major cell cycle-related regulators and cytoskeletal proteins in human umbilical cord mesenchymal stem cells (hucMSCs). A WST-1 assay showed that the proliferation of SMG-exposed hucMSCs was lower than a control group. Furthermore, flow cytometry analysis demonstrated that the percentage of SMG-exposed hucMSCs in the G0/G1 phase was higher than the control group. A western blot analysis revealed there was a downregulation of cyclin A1 and A2 expression in SMG-exposed hucMSCs as well. The expression of cyclin-dependent kinase 4 (cdk4) and 6 (cdk6) were also observed to be reduced in the SMG-exposed hucMSCs. The total nuclear intensity of SMG-exposed hucMSCs was also lower than the control group. However, there were no differences in the nuclear area or nuclear-shape value of hucMSCs from the SMG and control groups. A western blot and quantitative RT-PCR analysis showed that SMG-exposed hucMSCs experienced a downregulation of bata-actin and alpha-tubulin compared to the control group. SMG generated the reorganization of microtubules and microfilaments in hucMSCs. Our study supports the idea that the downregulation of major cell cycle-related proteins and cytoskeletal proteins results in the remodeling of the cytoskeleton and the proliferation of hucMSCs.

SETD8 promotes stemness characteristics and is a potential prognostic biomarker of gastric adenocarcinoma

SETD8 is a lysine methyltransferase containing an SET domain, which is involved in the carcinogenesis of many cancer types through monomethylation of the histone H4 lysine 20. However, its prognostic value and underlying mechanisms in gastric adenocarcinoma (GA) have not been extensively studied. Here, we assessed SETD8 expression and its relationship with clinicopathological parameters, cancer stemness-related proteins, cell cycle-related proteins, and PI3K/Akt pathway proteins in GA. SETD8 expression in GA tissues was correlated with the primary tumor stage, lymph node metastasis, tumor size, gross type, and clinical stage. SETD8 was an independent predictor of poor overall survival of patients with GA. Cox regression analysis showed that SETD8 is a potential biomarker of unfavorable clinical outcomes in patients with GA. Moreover, SETD8 overexpression was associated with cancer stemness-related genes, cell cycle-related genes, and PI3K/Akt/NF-κB pathway genes in clinical GA tissue samples. SETD8 silencing downregulated the expression of cancer stemness-associated genes (LSD1 and SOX2) and inhibited GA cell proliferation, spheroid formation, invasion, and migration. Additionally, LY294002 significantly reduced the expression of SETD8, pAkt-Ser473, pPI3K-p85, and NFκB-p65 in MKN74 and MKN28 cells. SETD8 may be a novel cancer stemness-associated protein and potential prognostic biomarker in GA.

Synergistic Antiproliferative Effect of Ribociclib (LEE011) and 5-Fluorouracil on Human Colorectal Cancer.

Colorectal cancer (CRC) is one of the most common malignant tumors in the world. This study aimed to investigate the anticancer effect of the combination treatment of Ribociclib (LEE011) and 5-Fluorouracil (5-FU) on CRC cells. HT-29 and SW480 cells were treated with LEE011, 5-FU, or the combination of LEE011 and 5-FU. Cell viability and cycle were investigated through 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay and flow cytometry. The expression of cell cycle-related proteins was determined through western blot. The combined treatment of LEE011 with 5-FU synergistically reduced cell viability in HT-29 and SW480 cells. Specifically, it induced cell cycle arrest at the G1 phase, down-regulated the phosphorylation of retinoblastoma protein and the expression of p53. LEE011 exhibited potential as an effective therapeutic inhibitor for the combination treatment of CRC patients.

The Anti-tumor Effects of p-Coumaric Acid on Melanoma A375 and B16 Cells.

Background: Existing research shows that p-coumaric acid (p-CA) can inhibit the proliferation of a variety of tumor cells in vitro. However, there are no reports on the anti-tumor effects of p-CA on melanoma cells. In this study, the inhibitory effects of p-CA on mouse melanoma B16 and human melanoma A375 cells are reported, and the related mechanisms are investigated.Methods: CCK-8 assay was used to detect the effects of p-CA on cell vitality, colony formation assay was used to observe the effects on cell proliferation, Hoechst 33,258 staining was used to observe the morphology of apoptotic cells, flow cytometry was used to detect the effects on apoptosis and the cell cycle, and western blot was used to measure the levels of cell cycle- and apoptosis-related signaling pathway proteins.Results: p-CA significantly inhibits cell proliferation of A375 and B16 cells in a dose-dependent manner and obviously induced cell morphological changes. p-CA arrested A375 cells in the S phase by downregulating the cell cycle-related proteins Cyclin A and CDK2, and arrested B16 cells in the G0–G1 phase through downregulating the cell cycle-related proteins Cyclin E and CDK2. In addition, p-CA significantly promoted apoptosis of A375 and B16 cells. Furthermore, p-CA significantly upregulated the levels of Apaf1 and Bax and downregulated the levels of Bcl-2, and subsequently increased the levels of cytoplasmic cytochrome c (Cyto-c), cleaved caspase-3, and cleaved caspase-9, leading to apoptosis in A375 and B16 cells.Conclusion: p-CA can significantly inhibit the proliferation of human and mouse melanoma cells in vitro. Our research is a step in the development of anti-melanoma drugs.