OBJECTIVE: To investigate the effect of Bmi-1 expression on the chemosensitivity of THP-1 cells and its relative mechanism. METHODS: The pGenesil-2-Bmi-1 1 siRNA, p-MSCV-Bmi-1 plasmid was transfected into THP-1 cells to reduce or increase the expression of Bmi-1. The expression of Bmi-1 mRNA and protein was verified by PCR and Western blot. The effect of camptothecin (CPT) on the proliferation and chemosensitivity of THP-1 cells affected by Bmi-1 gene were detected by MTT assay. The expression of DNA double-strand breaks marker-γ-H2AX was detected by immunofluorescence assay. Mitochondrial membrane potential and apoptosis were observed by flow cytometry. The expression of Cytochrome C, Caspase 3, Bax and BCL-2 was detected by Western blot. RESULTS: Silencing Bmi-1 could inhibit proliferation and enhance the sensitivity of THP-1 cells to CPT, while overexpressed Bmi-1 could promote the cell proliferation and attenucate sensitivity of THP-1 cells to CPT. Silencing Bmi-1 could enhance CPT-induced DNA double-strand breaks, decrease mitochondrial membrane potential and promote CPT-induced apoptosis. While increasing Bmi-1 gene expression could attenuate CPT-induced DNA double-strand breaks, enhamce mitochondrial membrane potential and significantly reduce CPT-induced apoptosis of cells. CONCLUSION Bmi-1 expression could influence the sensitivity of THP-1 cells to CPT, and its relative mechanism may relate to DNA double-strand breaks and endogenous apoptotic pathways.
Apoptosis ; Camptothecin/pharmacology* ; Cell Line, Tumor ; Cell Proliferation ; THP-1 Cells

OBJECTIVETo explore the effect of Shengjiang Xiexin Decoction (SXD) on the intestinal mucosal and functional cells of rats after irinotecan (CPT-11) chemotherapy.

METHODSTotally 24 healthy Sprague-Dawley (SD) male rats were divided into three groups, the normal control group, the CPT-11 group, the SXD combined CPT-11 group according to random digit table, 8 in each group. CPT-11 was injected at the daily dose of 150 mg/kg to rats in the CPT-11 group and the SXD combined CPT-11 group from the caudal vein on the 4th day, once daily for 2 successive days to duplicate delayed diarrhea model. Equal volume of normal saline was injected to rats in the normal control group from the caudal vein. SXD at 2 g/mL (10 g/kg body weight) was administered to rats in the SXD combined CPT-11 group by gastrogavage for 9 successive days. Deionized water was administered to rats in the CPT-11 group and the normal control group. Diarrhea was observed at 48, 60, 72, 84, 96, and 108 h to calculate the incidence rate of diarrhea. Meanwhile, scoring for diarrhea was performed by referring methods of Akinobu Kurita. Rats were killed on day 10, ileum, cecum, and colon tissues were collected and fixed in 10% formalin solution. HE staining was performed. Intestinal mucosa injuries were graded under light microscope according to the criterion of Chiu's score. The expressions of goblet cells and Paneth cells were observed by PAS stain. Enteroendocrine cells were observed by immunohistochemical CgA staining. Positive cells were counted and cumulative optical density (IOD) analyzed by Image-Pro-Plus 6.0.

RESULTSNo diarrhea occurred in rats of the normal control group at each time point. The incidence rate of diarrhea was 75.0% (6/8) at 48 h, 100.0% (8/8) at 60 h, 100.0% (8/8) at 72 h, 87.5% (7/8) at 84 h, 75.0% (6/8) at 96 h, and 75.0% (6/8) at 108 h in the CPT-11 group. The incidence rate of diarrhea was 25.0% (2/8) at 48 h, 50.0% (4/8) at 60 h, 12.5% (1/8) at 72 h, 0.0% (0/8) at 84 h in the SXD combined CPT-11 group. Compared with the same group at 60 h, scores for diarrhea at 48, 84, 96, and 108 h obviously decreased in the CPT-11 group, and scores for diarrhea at 48, 72, 84, 96, and 108 h obviously decreased in the SXD combined CPT-11 group (P < 0.05, P < 0.01). Compared with the same group at 72 h, scores for diarrhea at 84, 96, and 108 h obviously decreased in the CPT-11 group (P < 0.05, P < 0.01). Compared with the normal control group, scores for diarrhea increased in the CPT-11 group at each time point (P < 0.01); grading of ileum, cecum, and colon mucosal tissues increased (P < 0.05, P < 0.01); expressions of ileum and cecum mucosal epithelial goblet cells obviously decreased (P < 0.05); the number and expressions of ileum and cecum mucosal epithelial Paneth cells increased (P < 0.01). Expressions of ilium endocrine cells increased, while those of cecum and colon endocrine cells decreased in the CPT-11 group (P < 0.01). Compared with the CPT-11 group, scores for diarrhea were obviously lowered (P < 0.05, P < 0.01), grading of ileum, and cecum mucosal tissues decreased (P < 0.05, P < 0.01); expressions of ileum, cecum, and colon mucosal epithelial goblet cells obviously increased (P < 0.05, P < 0.01); the number and expressions of ileum cecum mucosal epithelial Paneth cells increased (P < 0.05); expressions of cecum and colon endocrine cells increased (P < 0.05, P < 0.01) in the SXD combined CPT-11 group.

CONCLUSIONSXD played roles in preventing and treating CPT-11 induced delayed diarrhea by improving CPT-11 chemotherapy induced apoptosis and necrosis of intestinal mucosal and functional cells.

Animals ; Apoptosis ; Camptothecin ; adverse effects ; analogs & derivatives ; Colon ; Diarrhea ; Drug Therapy ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Ileum ; Intestinal Mucosa ; drug effects ; Male ; Rats ; Rats, Sprague-Dawley ; Wound Healing ; drug effects

OBJECTIVETo investigate the anticancer effect and its mechanism of SN-38 combined with sorafenib on hepatocellular cancer cell lines HepG-2 and BEL-7402.

METHODSSRB colorimetry was employed to measure the viability of HepG-2 and BEL-7402 cells after the treatment of SN-38 with sorafenib. Propidium iodide flow cytometric assay and DAPI staining were used to evaluate the apoptosis of HCC cells. Western blotting was conducted to detect the expression level of apoptosis-related and DNA damage-related proteins.

RESULTSSRB colorimetry showed the synergistic anticancer activities of SN-38 combined with sorafenib, with a combination index of <0.9. The apoptotic rates of HepG-2 cells in control, 60 nmol/L SN-38, 2.5μmol/L sorafenib and combination groups were 4.25%±2.45%, 28.95%±10.75%, 3.49%±2.49% and 53.19%±11.21%, respectively(P<0.05). Western blotting showed that the combination of these two drugs increased the enzymolysis of PARP, Caspase-8 and Caspase-3, and promoted the expression levels of p53, p21 and γ-H2AX significantly.

CONCLUSIONSN-38 and sorafenib have synergistic anticancer activity on hepatocellular carcinoma cells in vitro with the augmentation of apoptosis.

Apoptosis ; Camptothecin ; analogs & derivatives ; pharmacology ; Carcinoma, Hepatocellular ; pathology ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Cell Line, Tumor ; drug effects ; Cell Proliferation ; Cyclin-Dependent Kinase Inhibitor p21 ; metabolism ; Histones ; metabolism ; Humans ; Liver Neoplasms ; pathology ; Niacinamide ; analogs & derivatives ; pharmacology ; Phenylurea Compounds ; pharmacology ; Poly(ADP-ribose) Polymerases ; metabolism ; Tumor Suppressor Protein p53 ; metabolism

This study plans to prepare lipid bilayer-coated mesoporous silica nanoparticles (LMSNs) which are pH sensitive with core-shell structure to improve the tumor cell lethality of antitumor drug. The lipid coated mesoporous silica nanoparticles loaded with irinotecan (CPT-11) (CPT-11-LMSNs) were prepared by hot water-film hydration method, and the characterized its morphology, particle size and release in vitro. Meanwhile, the intracellular uptake and cell toxicity of CPT-11-LMSNs and intracellular accumulation of CPT-11 were evaluated on human breast carcinoma cell line (MCF-7). The results indicated that the mean diameter of the spherical LMSNs was (120.27 +/- 5.91) nm. The slow release in simulated normal physiological conditions and a rapid release under simulated intracellular condition demonstrated the pH sensitivity of CPT-11-MSNs in vitro. Moreover, the CPT-11-LMSN could improve the intracellular CPT-11 cumulant 2.1 times and reduce half maximal inhibitory concentration (IC50) values of CPT-11 1.4 times compared with CPT-11-MSNs, demonstrating a stronger cell lethality.
Antineoplastic Agents, Phytogenic ; administration & dosage ; pharmacology ; Camptothecin ; administration & dosage ; analogs & derivatives ; pharmacology ; Cell Proliferation ; drug effects ; Drug Carriers ; Humans ; Hydrogen-Ion Concentration ; Lipid Bilayers ; administration & dosage ; chemistry ; MCF-7 Cells ; Nanoparticles ; Particle Size ; Porosity ; Silicon Dioxide ; administration & dosage ; chemistry

OBJECTIVETo explore the relationship between SULF2 and WRN promoter methylation and chemosensitivity to irinotecan, and also the clinicopathological features in patients with gastric cancer.

METHODSThe chemosensitivity to irinotecan was tested by MTT assay. The methylation of SULF2 and WRN promoter in the fresh gastric cancer tissues was detected by methylation specific PCR. The differences of chemosensitivity and clinicopathological features of the methylation group were compared with that of the non-methylation group. The tumor growth in nude mice bearing human gastric cancer xenografts treated with CPT-11was also observed.

RESULTSThe methylation rates of SULF2 and WRN were 28.4% (29/102) and 23.5% (24/102), respectively. There were no significant association between promoter methylation and clinicopathological features of patients including age, gender, histologic type, lymphatic invasion, and TNM Stage. In all the 102 cases, there were 30 cases of irrinotecan-sensitive group, and 72 cases of the irrinotecan-resistant group. The SULF2 methylation rate was 46.7% (14/30)in the sensitive group, and 20.8% (15/72) in the resistant group (P = 0.008),The WRN methylation rate was 33.3% (10/30) in the sensitive group, and 19.4% (14/72) in the resistant group (P = 0.214). Gastric cancer tissues were more sensitive to irrinotecan when both the genes were methylated. The nude mice bearing human gastric cancer xenografts with SULF2 methylation were more sensitive to irrinotecan.

CONCLUSIONSThe detection of SULF2 and WRN promoter methylation may provide evidence for screening and targeting the most sensitive gastric cancer subpopulation suitable for personalized irrinotecan chemotherapy.

Antineoplastic Agents, Phytogenic ; pharmacology ; Camptothecin ; analogs & derivatives ; pharmacology ; DNA Methylation ; Exodeoxyribonucleases ; metabolism ; Humans ; Methylation ; Promoter Regions, Genetic ; RecQ Helicases ; metabolism ; Stomach Neoplasms ; metabolism ; Sulfotransferases ; metabolism ; Werner Syndrome Helicase

OBJECTIVETo investigate the efficacy of treatment with siRNA targeting Bcl-2 in combination with HCPT against H₂₂ hepatoma transplanted in mice.

METHODSsiRNA targeting Bcl-2 mRNA was successfully designed and synthesized. Then, the Bcl-2 siRNA was transfected into H₂₂ hepatoma transplanted in mice in combination with HCPT for treatment. The changes of tumor volume, body weight and survival rate were observed. Tumor tissues were processed into paraffin blocks and sections were stained with hematoxylin and eosin (HE) to investigate the morphological changes of the tumor cells. RT-polymerase chain reaction (PT-PCR) was used to assess the expression of Bcl-2 mRNA in tumors and cells. Cell cycle and apoptosis of H₂₂ hepatoma cells transplanted in mice were further determined by flow cytometry.

RESULTSAfter treatment for 21 days, the tumor volume was around (571.47 ± 67.31)mm³ in the group of siRNA in combination with HCPT, which was significant smaller than that of the groups of HCPT [(880.47 ± 107.31) mm³, P < 0.05], siRNA interfere [(1119.55 ± 158.60)mm³, P < 0.01] and saline (1357.64 ± 197.92)mm³, P < 0.01]. The median survival time of the group receiving siRNA in combination with HCPT treatment was 26 days, which was significantly longer than that of the group receiving HCPT (14 day, P < 0.05), siRNA interfere (21 day, P < 0.05) and saline (12 day, P < 0.05). Larger necrotic area, lower expression of Bcl-2 mRNA, less cells at S phase and more apoptotic cells could be obviously seen in tumor tissues in the group of siRNA in combination with HCPT treatment.

CONCLUSIONBcl-2 siRNA in combination with HCPT has good synergetic antitumor efficacy in H₂₂ hepatoma-bearing mice.

Animals ; Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; drug effects ; Camptothecin ; analogs & derivatives ; pharmacology ; Cell Cycle ; drug effects ; Drug Synergism ; Liver Neoplasms, Experimental ; metabolism ; pathology ; Male ; Mice ; Mice, Inbred BALB C ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; genetics ; Random Allocation ; Transfection ; Tumor Burden ; drug effects

To investigate the molecular mechanism of hydroxycamptothecin (HCPT)-mediated anti-hepatic fibrosis by evaluting its effects on expression of tumor growth factor-beta 1 (TGFb1), alpha-smooth muscle actin (a-SMA) and collagen I (Col I) in hepatic satellite cells (HSCs). Cultured HSCs were treated with different concentrations of HCPT: low-dose group, 0.25 mg/L; middle-dose group, 0.5 mg/L; high-dose group, 0.75 mg/L; and control group, 0 mg/L. Cell proliferation was assessed by the MTT assay. The mRNA expressions of TGFb1, a-SMA and Col I were determined by reverse transcription-polymerase chain reaction. The protein expressions of TGFb1 and a-SMA were detected by Western blot. The content of Col I in the cultured HSCs' supernatant was measured by enzyme-linked immunosorbent assay. The MTT absorbance values of the low-dose group (0.631+/-0.074), middle-dose group (0.469+/- 0.012) and high-dose group (0.204+/- 0.001) were significantly lower than that of the control group (0.793+/-0.098; F = 82.86, P less than 0.01). Compared with the control group, the HCPT-treated groups showed significantly down-regulated gene expressions of TGFb1 (control: 0.716+/-0.064 vs. low: 0.611+/-0.040, middle: 0.510+/-0.014, high: 0.403+/-0.026), a-SMA (control: 0.696+/-0.075 vs. low: 0.579+/-0.037, middle: 0.470+/-0.024, high: 0.299+/-0.017), and Col I (control: 1.019+/-0.056 vs. low: 0.835+/-0.022, middle: 0.696+/-0.055, high: 0.322+/-0.104) (all, P less than 0.01). Meanwhile, HCPT-treated HSCs showed significantly reduced protein expressions of TGFb1 (control: 0.872+/-0.053 vs. low: 0.654+/-0.047, middle: 0.545+/-0.042, high: 0.436+/-0.039) and a-SMA (control: 0.858+/-0.050 vs. low: 0.620+/-0.045, middle: 0.525+/-0.042, high: 0.434+/-0.052) (all, P less than 0.01). The Col I levels secreted by HSCs were significantly lower in the HCPT-treated groups (low: 168.367+/-16.453 ng/ml; middle: 141.284+/-11.731 ng/ml; high: 132.910+/-10.048 ng/ml) than in the control group (188.733 +/-18.299 ng/ml) (all, P less than 0.01). The mechanism of HCPT-mediated anti-hepatic fibrosis may involve down-regulation of TGFb1 expression to inhibit HSC proliferation and activation, as well as reduction of Col I synthesis and secretion.
Actins ; metabolism ; Animals ; Camptothecin ; analogs & derivatives ; pharmacology ; Cell Proliferation ; Cells, Cultured ; Collagen Type I ; metabolism ; Hepatic Stellate Cells ; cytology ; drug effects ; metabolism ; Rats ; Rats, Sprague-Dawley ; Transforming Growth Factor beta1 ; metabolism

The study is to report the investigation of the effects of isorhamnetin on CYP3A4 and herb-drug interaction. A reporter gene assay is used to test pregnane X receptor transactivation action, qRT-PCR and a luminescence-based assay were applied to determine mRNA induction and enzyme activity of CYP3A4 after isorhamnetin treatment. The interaction of irinotecan and isorhamnetin was assessed by inhibition assay of cell proliferation. Isorhamnetin at 1, 10 and 25 micromol x L(-1) transactivated the CYP3A4 reporter construct and upregulated CYP3A4 mRNA as well in a dose-dependent manner. However, isorhamnetin had no effect on enzyme activity of CYP3A4 and irinotecan HepG2 cytotoxicity. In conclusion, activation of PXR by isorhamnetin played a role in the upregulation of CYP3A4 mRNA. Moreover, joint action of isorhamnetin with other drugs may not be associated with the herb-drug interaction.
Antineoplastic Agents, Phytogenic ; pharmacology ; Camptothecin ; analogs & derivatives ; pharmacology ; Cell Proliferation ; drug effects ; Cytochrome P-450 CYP3A ; genetics ; metabolism ; Dose-Response Relationship, Drug ; Hep G2 Cells ; Herb-Drug Interactions ; Humans ; Quercetin ; administration & dosage ; analogs & derivatives ; pharmacology ; RNA, Messenger ; metabolism ; Receptors, Steroid ; metabolism ; Transcriptional Activation ; drug effects ; Up-Regulation

OBJECTIVETo investigate the effect of hydroxycamptothecin (HCPT) on the proliferation, cell cycle and apoptosis of human lung carcinoma cell line A549.

METHODSThe growth of A549 cells exposed to HCPT was observed by staining with acridine orange/ethidium bromide dye. Agarose gel electrophoresis was performed to detect DNA fragmentation of the apoptotic cells. The cell cycle distribution of the exposed cells was analyzed using flow cytometry, and cell apoptosis was examined with annexin V-FITC/PI staining. RT-PCR was used to investigate Bcl-2 gene expression changes in the exposed cells.

RESULTSAgarose gel electrophoresis of the DNA from HCPT-treated cells showed a DNA ladder, and typical apoptotic appearance of the exposed cells was observed under fluorescence microscope. Treatment of A549 cells with 1 µmol/L HCPT for 24 h resulted in a cell apoptosis rate of 18.11%, significantly higher than the rate in control cells (0.09%, P<0.05). The treatment also caused a significant reduction of Bcl-2 mRNA expression by 70% (P<0.05).

CONCLUSIONHCPT can significantly inhibit the proliferation, induce apoptosis, and down-regulate Bcl-2 gene expression in human lung carcinoma cell line A549, suggesting the involvement of Bcl-2 gene in the inhibitory effect of HCPT on A549 cells.

Camptothecin ; analogs & derivatives ; pharmacology ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Down-Regulation ; Gene Expression Regulation, Neoplastic ; drug effects ; Genes, bcl-2 ; Humans ; Transfection

Ataxia-telangiectasia (A-T) is an autosomal recessive disorder characterized by cerebellar ataxia and oculocutaneous telangiectasias. The gene mutated in this disease, ATM (A-T, mutated), encodes a 370-kDa Ser/Thr protein kinase. ATM not only mediates cellular response to DNA damage but also acts as an activator of Akt in response to insulin. However, despite intensive studies, the mechanism underlying the neuronal degeneration symptoms of human A-T is still poorly understood. We found that the topoisomerase inhibitors etoposide and camptothecin readily induced apoptosis in undifferentiated proliferating SH-SY5Y cells but could not induce apoptosis in neuronally differentiated SH-SY5Y cells. In addition, etoposide induced p53 phosphorylation and H2AX foci formation in proliferating SH-SY5Y cells but failed to do so in differentiated SH-SY5Y cells. Moreover, while inhibition of ATM in undifferentiated SH-SY5Y cells partially protected them from etoposide-induced apoptosis, the same treatment had no effect on cell viability in differentiated SH-SY5Y cells. These results suggest that DNA damage or defective response to DNA damage is not the cause of neuronal cell death in human A-T. In contrast, we discovered that Akt phosphorylation was inhibited when ATM activity was suppressed in differentiated SH-SY5Y cells. Furthermore, inhibition of ATM induced apoptosis following serum starvation in neuronally differentiated SH-SY5Y cells but could not trigger apoptosis under the same conditions in undifferentiated proliferating SH-SY5Y cells. These results demonstrate that ATM mediates the Akt signaling and promotes cell survival in neuron-like human SH-SY5Y cells, suggesting that impaired activation of Akt is the reason for neuronal degeneration in human A-T.
Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; Ataxia Telangiectasia ; pathology ; Ataxia Telangiectasia Mutated Proteins ; Camptothecin ; pharmacology ; Cell Cycle Proteins ; antagonists & inhibitors ; metabolism ; Cell Differentiation ; Cell Line, Tumor ; DNA Damage ; DNA-Binding Proteins ; antagonists & inhibitors ; metabolism ; Etoposide ; pharmacology ; Histones ; metabolism ; Humans ; Morpholines ; pharmacology ; Neuroblastoma ; pathology ; Neurons ; cytology ; Phosphorylation ; Protein-Serine-Threonine Kinases ; antagonists & inhibitors ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Pyrones ; pharmacology ; Signal Transduction ; Topoisomerase Inhibitors ; pharmacology ; Tumor Suppressor Protein p53 ; metabolism ; Tumor Suppressor Proteins ; antagonists & inhibitors ; metabolism