PURPOSE: This study investigated the role of natriuretic peptide receptor 2 (NPR2) on cell proliferation and testosterone secretion in mouse Leydig cells. MATERIALS AND METHODS: Mouse testis of different postnatal stages was isolated to detect the expression C-type natriuretic peptide (CNP) and its receptor NPR2 by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Leydig cells isolated from mouse testis were cultured and treated with shNPR2 lentiviruses or CNP. And then the cyclic guanosine monophosphate production, testosterone secretion, cell proliferation, cell cycle and cell apoptosis in mouse Leydig cells were analyzed by ELISA, RT-qPCR, Cell Counting Kit-8, and flow cytometry. Moreover, the expression of NPR2, cell cycle, apoptosis proliferation and cell cycle related gene were detected by RT-qPCR and Western blot. RESULTS: Knockdown of NPR2 by RNAi resulted in S phase cell cycle arrest, cell apoptosis, and decreased testosterone secretion in mouse Leydig cells. CONCLUSIONS: Our study provides more evidences to better understand the function of CNP/NPR2 pathway in male reproduction, which may help us to treat male infertility.
Animals ; Apoptosis ; Blotting, Western ; Cell Count ; Cell Cycle ; Cell Cycle Checkpoints ; Cell Proliferation ; Enzyme-Linked Immunosorbent Assay ; Flow Cytometry ; Germ Cells ; Guanosine Monophosphate ; Humans ; Infertility, Male ; Lentivirus ; Leydig Cells ; Male ; Mice ; Natriuretic Peptide, C-Type ; Polymerase Chain Reaction ; Receptors, Peptide ; Reproduction ; Reverse Transcription ; RNA Interference ; S Phase ; Testicular Diseases ; Testis ; Testosterone

Orthodenticlehomeobox 1 (OTX1) overexpression had previously been associated with the progression of several tumors. The present study aimed to determine the expression and role of OTX1 in human hepatocellular carcinoma (HCC). The expression level of OTX1 was examined by quantitative real-time PCR (qRT-PCR) in 10 samples of HCC and paired adjacent non-cancerous tissues, and by immunohistochemistry (IHC) analysis in 128 HCC samples and matched controls. The relationship between OTX1 expression and the clinicopathological features werealso analyzed. Furthermore, the effects of OTX1 knockdown on cell proliferation and migration were determined in HCC cell lines. Axenograft mouse model was also established to investigate the role of OTX1 in HCC tumor growth. TheqRT-PCR and IHC analyses revealed that OTX1 was significantly elevated in HCC tissues compared with the paired non-cancerous controls. Expression of OTX1 was positively correlated with nodal metastasis status (P = 0.009) and TNM staging (P = 0.001) in HCC tissues. In addition, knockdown of OTX1 by shRNA significantly inhibited the proliferation and migration, and induced cell cycle arrest in S phase in vitro. Tumor growth was markedly inhibited by OTX1 silencing in the xenograft. Moreover, OTX1 silencing was causable for the decreased phosphorylation level of ERK/MAPK signaling. In conclusion, OTX1 contributes to HCC progression possibly by regulation of ERK/MAPK pathway. OTX1 may be a novel target for molecular therapy towards HCC.
Aged ; Animals ; Blotting, Western ; Carcinoma, Hepatocellular/metabolism/*pathology ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Disease Progression ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Immunohistochemistry ; Liver/metabolism/pathology ; Liver Neoplasms/metabolism/*pathology ; Lymphatic Metastasis ; MAP Kinase Signaling System ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Middle Aged ; Neoplasm Staging ; Otx Transcription Factors/antagonists & inhibitors/genetics/*metabolism ; Phosphorylation ; RNA Interference ; Real-Time Polymerase Chain Reaction ; S Phase Cell Cycle Checkpoints ; Transplantation, Heterologous

OBJECTIVETo investigate the anti-tumor activity and molecular mechanism of Tonglian Decoction (, TLD) on esophageal carcinoma Eca109 cells.

METHODSEca109 cells were treated with TLD and its separated formulae, including the clearing-heat and detoxification formula (Q), activating-blood and promoting-qi formula (H) and nourishing-yin and blood formula (Z). Cell proliferation was measured using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay, cell morphology was observed using a microscope, the cell cycle was measured using flow cytometry and the activity of the nuclear factor-kappa B (NF-κB) signal pathway was detected by Western blot.

RESULTSThe half maximal inhibitory concentrations of TLD, Q and H were 386, 771 and 729 mg/L, respectively. TLD, Q and H significantly inhibited cell proliferation, with 69.43%, 60.84% and 61.90% of treated cells in the G phase of the cell cycle. The percentage of cells in S phase increased significantly after treatment with TLD, Q, and H compared with the control group (P<0.05), and TLD showed the strongest effect. Z had no influence on the cell cycle compared with the control group (P>0.05). Western blot detection indicated slight differences in the inhibition of the NF-κB pathway by the different formulae. TLD formula strongly inhibited IKKβ, NF-κB, interleukin-6 and tumor necrosis factor-α expression compared with the control group.

CONCLUSIONSTLD inhibited Eca109 cell proliferation by arresting cells in S phase. The possible mechanism might be related to inhibiting the NF-κB transduction cascade. The combination of the herbs found in the three separate formulae, H, Q and Z, work synergistically in TLD to produce the inhibitory effects of TLD treatment on Eca109 proliferation.

Blotting, Western ; Cell Count ; Cell Cycle Checkpoints ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cell Shape ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Esophageal Neoplasms ; metabolism ; pathology ; Flow Cytometry ; Humans ; Inhibitory Concentration 50 ; NF-kappa B ; metabolism ; S Phase ; drug effects ; Signal Transduction ; drug effects

OBJECTIVETo investigate the effect of solanine on the growth of human prostate cancer cell xenograft in nude mice.

METHODSHuman prostate cancer Du145 cells were injected into the subcutaneous layers on the back of nude mice. After a week, the mice bearing subcutaneous tumor graft were randomly divided into solanine treatment group and saline control group for treatment for 3 weeks. The tumor grafts were then harvested to evaluate the inhibition rate. The mRNA and protein expressions of cell cycle-related genes in the tumors were detected by qRT-PCR and Western blotting, respectively, and tumor cell apoptosis was detected using TUNEL method.

RESULTSThe tumor growth rate in solanine-treated group was significantly slower than that in the control group (P<0.01). The mRNA and protein expressions of C-myc, cyclin D1, cyclin E1, CDK2, CDK4 and CDK6 were significantly inhibited by solanine. Solanine significantly up-regulated p21 mRNA and protein expression in the tumors and induced a higher apoptosis rate of the tumor cells than saline (P<0.01).

CONCLUSIONThe tumor-inhibition effect of solanine is probably mediated by regulating the expressions of genes related with G1/S cell cycle arrest and cell apoptosis.

Animals ; Apoptosis ; Cyclin-Dependent Kinases ; metabolism ; Cyclins ; metabolism ; G1 Phase Cell Cycle Checkpoints ; Humans ; Male ; Mice ; Mice, Nude ; Neoplasm Transplantation ; pathology ; Prostatic Neoplasms ; drug therapy ; pathology ; S Phase ; Solanine ; pharmacology

OBJECTIVETo study the pattern of DNA double-strand break (DSB) formation in S-phase cells after thermal damage and explore the mechanisms behind heat sensitivity of S-phase cells and delayed DSBs.

METHODSFlow cytometry was used to analyze the cell cycle arrest in H1299 cells exposed to thermal damage, and EdU incorporation assay was employed to evaluate the DNA replication capacity of the cells. The cells synchronized in S phase were obtained by serum starvation and DSBs were observed dynamically using neutral comet assay. Trypan blue dye exclusion technique was used to analyze the cell viability after thermal damage. Western blotting (WB) was used to detect the phosphorylation of ATM and DNA binding RAD18.

RESULTSThe percentage of S-phase cells increased significantly after exposure of the cells to 45 degrees celsius; for 1 h (P<0.01). The time-dependent variation pattern of EdU incorporation was similar to that of S-phase cell fraction. The comet tail began to appear only after incubation of the cells at 37 degrees celsius; for some time and the Olive tail moment (OTM) increased with prolonged incubation. Cell death remained low until 7.5 h after heat exposure of the S-phase cells and then increased rapidly. The phosphorylation of ATM first increased but then decreased drastically. In cells with heat exposure, DNA binding RAD18 was attenuated obviously compared that in non-exposed cells.

CONCLUSIONThermal damage causes cell cycle arrest in S phase, and delayed fatal DSBs occur in the arrested cells due to persistent replication and DNA damage repair suppression, which are the possible cause of heat sensitivity of S-phase cells.

Ataxia Telangiectasia Mutated Proteins ; metabolism ; Cell Cycle Checkpoints ; Cell Line ; Cell Survival ; Comet Assay ; DNA Breaks, Double-Stranded ; DNA Repair ; DNA Replication ; DNA-Binding Proteins ; metabolism ; Hot Temperature ; Humans ; Phosphorylation ; S Phase ; Ubiquitin-Protein Ligases

PURPOSE: Several studies have proven that EGCG, the primary green tea catechin, and glucosamine-6-phosphate (PGlc) reduce triglyceride contents in 3T3-L1 adipocytes. The objective of this study is to evaluate the combination effect of EGCG and PGlc on decline of accumulated fat in differentiated 3T3-L1 adipocytes. METHODS: EGCG and PGlc were administered for 6 day for differentiation of 3T3-L1 adipocytes. Cell viability was measured using the CCK assay kit. In addition, TG accumulation in culture 3T3-L1 adipocytes was investigated by Oil Red O staining. We examined the expression level of several genes and proteins associated with adipogenesis and lipolysis using real-time RT-PCR and Western blot analysis. A flow cytometer Calibar was used to assess the effect of EGCG and PGluco on cell-cycle progression of differentiating 3T3-L1 cells. RESULTS: Intracelluar lipid accumulation was significantly decreased by combination treatment with EGCG 60 microM and PGlc 200 microg/m compared with control and EGCG treatment alone. In addition, use of combination treatment resulted in directly decreased expression of PPARgamma, C/EBPalpha, and SREBP1. In addition, it inhibited adipocyte differentiation and adipogenesis through downstream regulation of adipogenic target genes such as FAS, ACSL1, and LPL, and the inhibitory action of EGCG and PGlc was found to inhibit the mitotic clonal expansion (MCE) process as evidenced by impaired cell cycle entry into S phase and the S to G2/M phase transition of confluent cells and levels of cell cycle regulating proteins such as cyclin A and CDK2. CONCLUSION: Combination treatment of EGCG and PGlc inhibit-ed adipocyte differentiation through decreased expression of genes related to adipogenesis and adipogenic and cell cycle arrest in early stage of adipocyte differentiation.
3T3-L1 Cells ; Adipocytes* ; Adipogenesis* ; Blotting, Western ; Catechin ; Cell Cycle Checkpoints* ; Cell Cycle* ; Cell Survival ; Cyclin A ; Lipolysis ; Phase Transition ; PPAR gamma ; S Phase ; Tea ; Triglycerides

In this study, a new parameter, S phase cell percentage (S fraction) normalized BrdU (SFN-BrdU) incorporation rate, was introduced to detect S arrest. The results showed a positive linear correlation between the BrdU incorporation rate and the S fraction in unperturbed 16HBE cells. Theoretical analysis indicated that only S arrest could result in a decrease in the SFN-BrdU incorporation rate. Additionally, the decrease in SFN-BrdU incorporation rate and the activation of DNA damage checkpoints further demonstrated that S arrest was induced by diethyl sulfate treatment of 16HBE cells. In conclusion, SFN-BrdU incorporation rate can be used to detecting S arrest.
Bromodeoxyuridine ; pharmacokinetics ; Cell Proliferation ; DNA Damage ; Epithelial Cells ; cytology ; Humans ; S Phase ; S Phase Cell Cycle Checkpoints

Icaritin, a prenylflavonoid derivative from Epimedium Genus, has been shown to exhibit many pharmacological and biological activities. However, the function and the underlying mechanisms of icaritin in human non-small cell lung cancer have not been fully elucidated. The purpose of this study was to investigate the anticancer effects of icaritin on A549 cells and explore the underlying molecular mechanism. The cell viability after icaritin treatment was tested by MTT assay. The cell cycle distribution, apoptosis and reactive oxygen species (ROS) levels were analyzed by flow cytometry. The mRNA and protein expression levels of the genes involved in proliferation and apoptosis were respectively detected by RT-PCR and Western blotting. The results demonstrated that icaritin induced cell cycle arrest at S phase, and down-regulated the expression levels of S regulatory proteins such as Cyclin A and CDK2. Icaritin also induced cell apoptosis characterized by positive Hoechst 33258 staining, accumulation of the Annexin V-positive cells, increased ROS level and alteration in Bcl-2 family proteins expression. Moreover, icaritin induced sustained phosphorylation of ERK and p38 MAPK. These findings suggested that icaritin might be a new potent inhibitor by inducing S phase arrest and apoptosis in human lung carcinoma A549 cells.
Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; drug effects ; Cell Line, Tumor ; Flavonoids ; pharmacology ; Humans ; Lung Neoplasms ; drug therapy ; metabolism ; pathology ; MAP Kinase Signaling System ; drug effects ; Neoplasm Proteins ; biosynthesis ; Reactive Oxygen Species ; metabolism ; S Phase Cell Cycle Checkpoints ; drug effects

OBJECTIVE: We compared the cell responsiveness of activated lymphocytes to rapamycin, which blocks the G1/S transition, between patients with Alzheimer's disease (AD) and normal controls to assess the early phase control defect in cell cycle. METHODS: Blood samples of 26 patients with AD and 28 normal controls were collected to separate peripheral lymphocytes. We measured the proportion of each cell cycle phase in activated lymphocytes using flow cytometry and evaluated the responsiveness of these lymphocytes to rapamycin. RESULTS: The patients with AD were older than the normal controls (AD 74.03+/-7.90 yr vs. control 68.28+/-6.21 yr, p=0.004). The proportion of G1 phase cells in the AD group was significantly lower than that in the control group (70.29+/-6.32% vs. 76.03+/-9.05%, p=0.01), and the proportion of S phase cells in the AD group was higher than that in control group (12.45+/-6.09% vs. 6.03+/-5.11%, p=0.001). Activated lymphocytes in patients with AD were not arrested in the G1 phase and they progressed to the late phase of the cell cycle despite rapamycin treatment, in contrast to those of normal subjects. CONCLUSION: The patients with AD probably have a control defect of early phase cell cycle in peripheral lymphocytes that may be associated with the underlying pathology of neuronal death.
Alzheimer Disease ; Cell Cycle ; Cell Cycle Checkpoints ; Flow Cytometry ; G1 Phase ; Humans ; Lymphocytes ; Neurons ; S Phase ; Sirolimus

OBJECTIVES: The inactivation of the tumor suppressor gene p16INK4a plays an important role in the development of malignant tumors, including oral squamous cell carcinoma. The p16 gene is involved in the p16/cyclin-dependent kinase/retinoblastoma (Rb) gene pathway of cell cycle control. The p16 protein is considered a negative regulator of this pathway. The p16 gene encodes an inhibitor of cyclin-dependent kinases 4 and 6 which regulate the phosphorylation of the retinoblastoma gene and G1 to S phase transition in the cell cycle. However, the p16 gene can lose its functionality through point mutations, loss of heterozygosity or methylation of its promoter region. MATERIALS AND METHODS: In this study, the authors analyzed the correlation between various clinicopathological findings-patient age, gender and smoking, disease recurrence, tumor size, stage, and differentiation- and p16 protein expression or p16 promoter hypermethylation in 59 cases of head and neck squamous cell carcinoma. RESULTS: The results revealed p16 protein expression and p16 promoter hypermethylation in 28 cases (47.5%) and 21 cases (35.6%), respectively, of head and neck squamous cell carcinoma. However, neither p16 protein expression nor p16 promoter hypermethylation had any statistical influence on clinicopathological findings or survival rate. CONCLUSION: This data, and a review of the literature, suggest that p16 promoter hypermethylation cannot yet be used as an independent prognostic factor influencing carcinogenesis, but must be considered as an important factor along with other genetic alterations affecting the pRb pathway.
Carcinoma, Squamous Cell ; Cell Cycle ; Cell Cycle Checkpoints ; Cyclin-Dependent Kinases ; Epigenomics ; Genes, p16 ; Genes, Retinoblastoma ; Genes, Tumor Suppressor ; Head ; Humans ; Loss of Heterozygosity ; Methylation ; Neck ; Phosphorylation ; Point Mutation ; Prognosis ; Recurrence ; S Phase ; Smoke ; Smoking