Effect of Nimesulide on proliferation and apoptosis of human hepatoma SMMC-7721 cells

Therapeutic potential of Rosa roxburghii folium extract in insomnia treatment: a comprehensive evaluation of behavioral and neurochemical effects in a PCPA-induced mouse model

BACKGROUND

Insomnia, a prevalent sleep disorder, detrimentally affects quality of life and is often challenging to manage with conventional treatments. This study delved into identifying and quantifying the main compounds by employing ultra-performance liquid chromatography-Q-Exactive-Orbitrap mass spectrometry, and further to evaluate the therapeutic potential of Rosa roxburghii folium (RRF) extract, with multiple pharmacological activities. Previous research had hinted at the efficacy of glycosides in influencing the γ-aminobutyric acid (GABAergic) system, which plays a pivotal role in sleep regulation. Utilizing a p-chlorophenylalanine-induced insomnia model in BALB/C mice, this investigation aimed to unravel the effects of various dosages of RRF extract on sleep quality and elucidated its mechanism of action.

RESULTS

A total of 66 compounds in the RRF extract were analyzed. Behavioral assessments demonstrated notable enhancements in sleep duration and latency. Biochemical analyses further corroborated these findings, revealing modulation in neurotransmitter levels indicative of a potential mechanism through the GABAergic and serotoninergic pathways. Additionally, histological evaluations suggested anti-inflammatory and antioxidant effects of the RRF extract.

CONCLUSION

The findings from this study underscored the therapeutic efficacy of RRF extract in combating insomnia, particularly highlighting its glycoside components' role. The extract's significant improvement in sleep duration and latency, alongside its modulation of neurotransmitter levels, showcases its potential as a natural remedy for insomnia. Through its action on the GABAergic and serotoninergic pathways, as well as its anti-inflammatory and antioxidant effects, RRF extract emerges as a promising candidate for insomnia treatment, offering a holistic approach to sleep disorder management. © 2024 Society of Chemical Industry.

Phase 1 study of the safety, pharmacokinetics, and preliminary efficacy of CA102N as monotherapy and in combination with trifluridine-tipiracil in patients with locally advanced or metastatic solid tumors

CA102N is a covalently bound conjugate of modified nimesulide (Nim) and NaHA, the sodium salt of hyaluronic acid (HA). HA is a natural ligand of cluster of differentiation 44 (CD44), which is over-expressed in colorectal cancer (CRC). CA102N is designed to deliver nimesulide directly to the tumor via the interaction of HA and CD44. A Phase 1, 2-part (dose escalation, dose expansion), non-randomized, open-label, first-in-human study of CA102N, as monotherapy and in combination with trifluridine-tipiracil, was conducted in patients with locally advanced or metastatic solid tumors. The CA102N doses evaluated were 0.36 mg/kg, 0.54 mg/kg, and 0.72 mg/kg Nim equivalent. The primary endpoints were dose-limiting toxicities (DLTs) in Cycle 1 as well as serious adverse events (SAEs) and treatment-emergent adverse events (TEAEs) throughout the study; secondary endpoints were pharmacodynamics parameters, objective tumor response, and urinary pharmacodynamics markers of target inhibition. Between April 2019 and October 2021, 37 patients were enrolled in 3 US centers. No DLTs were observed in Part 1, and 0.72 mg/kg Nim equivalent was the dose selected for Part 2. In total, 52 TEAEs in 18 patients were CA102N-related; 4 (in 3 patients) were ≥ Grade 3. Exploratory analysis in the dose expansion cohort revealed a median progression-free survival of 3.7 (1.0, 6.77) months. Based on this study, CA102N as monotherapy or in combination with trifluridine-tipiracil, was safe and well-tolerated at the recommended Phase 2 dose of 0.72 mg/kg Nim equivalent in patients with locally advanced or metastatic solid tumors. Preliminary evidence of antitumor activity in CRC warrants further clinical development. (ClinicalTrials.gov registration number: NCT03616574. Registration date: August 6, 2018).

Nimesulide analogues: From anti-inflammatory to antitumor agents

Nimesulide is a nonsteroidal anti-inflammatory drug possessing analgesic and antipyretic properties. This drug is considered a selective cyclooxygenase-2 (COX-2) inhibitor and, more recently, has been associated to antitumor activity. Thus, numerous works have been developed to modify the nimesulide skeleton aiming to develop new and more potent and selective COX-2 inhibitors as well as potential anticancer agents. This review intends to provide an overview on analogues of nimesulide, including the general synthetic approaches used for their preparation and structural diversification and their main anti-inflammatory and/or antitumor properties.

From COX-2 inhibitor nimesulide to potent anti-cancer agent: synthesis, in vitro, in vivo and pharmacokinetic evaluation

Cyclooxygenase-2 (COX-2) inhibitor nimesulide inhibits the proliferation of various types of cancer cells mainly via COX-2 independent mechanisms, which makes it a good lead compound for anti-cancer drug development. In the presented study, a series of new nimesulide analogs were synthesized based on the structure-function analysis generated previously. Some of them displayed very potent anti-cancer activity with IC(50)s around 100 nM-200 nM to inhibit SKBR-3 breast cancer cell growth. CSUOH0901 (NSC751382) from the compound library also inhibits the growth of the 60 cancer cell lines used at National Cancer Institute Developmental therapeutics Program (NCIDTP) with IC(50)s around 100 nM-500 nM. Intraperitoneal injection with a dosage of 5  mg/kg/d of CSUOH0901 to nude mice suppresses HT29 colorectal xenograft growth. Pharmacokinetic studies demonstrate the good bioavailability of the compound.

In vitro and in vivo effects of a cyclooxygenase-2 inhibitor nimesulide analog JCC76 in aromatase inhibitors-insensitive breast cancer cells

Third generation aromatase inhibitors (AIs) are more effective than tamoxifen in the treatment of estrogen receptor (ER) positive breast cancer. However, long-term use of AIs commonly results in resistance. We examined whether compound JCC76{Cyclohexanecarboxylic acid [3-(2,5-dimethyl-benzyloxy)-4-(methanesulfonyl-methyl-amino)-phenyl]-amide}, an analog of Cyclooxygenase-2 (COX-2) inhibitor nimesulide, can inhibit the growth of AI-insensitive breast cancer cells and the mechanisms by which the compound affects cell proliferation. LTEDaro (long term estrogen deprived MCF-7aro cell) cells, which are a model for AI resistance, were used in this study. JCC76 effectively inhibited LTEDaro cell proliferation with an IC(50) of 2.75 ± 0.31 μM. Further investigations reveal that the compound significantly induced apoptosis in LTEDaro cells by decreasing pAKT, BCL-2 and pBad protein levels, which were all up regulated in the cells after long term estrogen deprivation. LTEDaro tumor size and weight were decreased in ovariectomized nude mice treated with the compound, and cell apoptosis in the tumor tissue was increased compared to the control. The animal weight remained almost unchanged which indicated the low toxicity of the compound. These results suggest that JCC76 overcame AI resistance by inducing cell apoptosis as illustrated in the in vitro and in vivo models. Collectively, results from this study provide data to support that nimesulide analog JCC76 may be a new drug candidate to treat AI-resistant breast cancers. It could be also used as a lead to design and synthesize more potent derivatives.

Preparation, safety, pharmacokinetics, and pharmacodynamics of liposomes containing Brucea javanica oil

Brucea javanica oil-loaded liposomes (BJOL) were prepared through thin film hydration method and characterized by transmission electron microscope, dynamic light scattering, and differential scanning calorimetry. Acute toxicity of B. javanica oil (BJO) in liposomes was assessed by determining the number of deaths of Kunming mice over intravenous treatment for 2 weeks. The pharmacokinetic behavior of the main active component (oleic acid) was studied in SD rats. The pharmacodynamics of BJOL was investigated using MMC-7721 cell lines and mice with Lewis lung cancer. The commercial emulsion of BJO (BJOE) was used as a reference. The data showed that BJOL had an average diameter of 108.2 nm with a zeta potential of -57.0 mV, drug loading of 3.60%, and entrapment efficiency of 92.40%. The area under curve of BJO in liposomes and emulsions were 2.31 and 1.15 mg min/ml, respectively. Compared with BJOE, mean residence time and elimination half-time (t(1/2)) increased 2.8- and 4.0-fold, respectively, and the clearance (CL) decreased 0.5-fold. In the acute toxicity test, the median lethal dose (LD(50)) of BJOE was 7.35 g/kg. In contrast, all mice treated with liposomes survived even at the highest dosage (12.70 g/kg). The IC(50) value of BJOL group was one third of that of BJOE group (p < 0.01), and a less weight loss was observed in the BJOL-treated animals (p < 0.05). In conclusion, the present study suggests that BJOL significantly decreased toxicity of BJO and enhance the antitumor activity. Therefore, liposomes may be a potential effective delivery vehicle for this lipophilic antitumor drug.

Survivin depletion preferentially reduces the survival of activated K-Ras-transformed cells

To identify cancer-specific targets, we have conducted a synthetic lethal screen using a small interfering RNA (siRNA) library targeting ∼4,000 individual genes for enhanced killing in the DLD-1 colon carcinoma cell line that expresses an activated copy of the K-Ras oncogene. We found that siRNAs targeting baculoviral inhibitor of apoptosis repeat-containing 5 (survivin) significantly reduced the survival of activated K-Ras-transformed cells compared with its normal isogenic counterpart in which the mutant K-Ras gene had been disrupted (DKS-8). In addition, survivin siRNA induced a transient G2-M arrest and marked polyploidy that was associated with increased caspase-3 activation in the activated K-Ras cells. These results indicate that tumors expressing the activated K-Ras oncogene may be particularly sensitive to inhibitors of the survivin protein. [Mol Cancer Ther 2007;6(1):269–76]

Antineoplastic effect of the cyclooxygenase inhibitor meloxicam on canine osteosarcoma cells

A decisive role in cancer development has been attributed to cyclooxygenase-2 (COX-2) activity, but the significance of COX-2 inhibitors in cancer treatment still needs to be thoroughly investigated. We studied the influence of meloxicam, a non-steroidal antiinflammatory drug with preferential inhibitory effects on COX-2 compared to COX-1, on canine osteosarcoma (D-17) cells. We demonstrated that D-17 cells expressed mRNA and COX-2 protein. Treatment with meloxicam induced a time- and dose-dependent inhibition of cellular growth. To determine if apoptosis plays a role in meloxicam-induced cell death, we performed agarose gel electrophoresis and found a DNA-ladder pattern, typically seen in apoptosis, as well as early apoptotic changes by Annexin V tests. Furthermore, electron microscopy revealed ultrastructural alterations typical of apoptosis. Quantification of apoptotic cells by immunohistochemical staining of caspase 3 confirmed the results. However, further studies with meloxicam are necessary to assess its potential use for treatment of osteosarcomas in dogs.

Hepatotoxicity of anti-inflammatory and analgesic drugs: ultrastructural aspects

With the increasing incidence of drug-induced liver disease, attempts are being made to better understand the mechanisms behind these frequently life-endangering reactions. Analgesics and anti-inflammatory drugs are a major group exhibiting hepatotoxicity. We review research relating to these reactions, focusing on ultrastructural findings, which may contribute to the comprehension and possible avoidance of drug-induced liver disease. We also present some original observations on clinical material and cultured cells exposed to acetaminophen alone or in combination with the antioxidant N-acetylcysteine or the P-glycoprotein inhibitor verapamil.

Cyclooxygenase-2 in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third leading cause of cancer related mortality worldwide. The incidence of HCC is rising worldwide, especially in the United States. The overall survival of patients with HCC is grim and currently no efficient secondary prevention or systemic treatments are available. Recent evidence suggests that COX-2 signaling is implicated in hepatocarcinogenesis and COX-2 inhibitors prevent HCC cell growth in vitro and in animal models. However, given the recently reported side effect associated with some of the COX-2 inhibitors, it is imperative to develop chemotherapeutic strategy that simultaneously targets COX-2 and other related key molecules in hepatocarcinogenesis or to utilize agents inhibiting COX-2 signaling in conjunction with other standard chemotherapy or radiation therapy. Such combinational therapeutic approaches are expected to provide synergistic anti-tumor effect with lesser side effect. In this regard, the recently delineated interplay between COX-2-derived PG signaling and other growth-regulatory pathways such as EGFR, Met, iNOS, VEGF and n-3 polyunsaturated fatty acids is expected to provide important therapeutic implications. This review summarizes the recent advances in understanding the mechanisms for COX-2-derived PG signaling in hepatocarcinogenesis and focuses on the newly unveiled interactions between PG cascade and other key signaling pathways that coordinately regulate HCC growth. Understanding these mechanisms and interplays will facilitate the development of more effective chemopreventive and therapeutic strategies.

Effects of COX-2 inhibitor with cisplatin on proliferation and apoptosis of pancreatic cancer cells

AIM: To investigate the effects of proliferation and apoptosis induced by cyclooxygenase-2 (COX-2) inhibitor celecoxib in combination with cisplatin.

METHODS: The human pancreatic cancer cell line BxPC-3 cells were treated with COX-2 inhibitors celecoxib and cisplatin. The cell relative viability was examined using 3 (4, 5-dimethylethiazoly 1-2-) 2, 5-diphonyl tetrazolium bromide (MTT) assays. the expression of COX-2 mRNA was detected by RT-PCR, flow cytometry and Hoechst-33258 were used to demonstrate apoptotic changes in celecoxib and cisplatin treated cells.

RESULTS: After treatment of BxPC-3 cells with celecoxib, as measured by MTT, cell viability was inhibited in a dose-dependent and time-dependent manner with an IC50 of 100 nM at the time of 24h. The expression of COX-2 mRNA could be significantly decreased by celecoxib. Furthermore, we demonstrated that the combination of celecoxib with cisplatin inhibited cell growth and induced cell apoptosis to a greater degree than either compound alone. The apoptotic morphologies were demonstrated by Hoechst-33 258.

CONCLUSION: Combination of celecoxib with cisplatin inhibits cell proliferation and induces cell apoptosis, and the potent effectiveness of celecoxib in combination with gemcitabine may hold a promise in the clinical treatment of pancreatic cancer.

Effects of indomethacin and/or casplatin on apoptosis of gastric cancer cells

AIM: To investigate the effects of indomethacin (IN) and casplain (CDDP) on apoptosis of gastric cancer cell line MGC803 and to provide the theoretic basis for gastric cancer therapy.

METHODS: Gastric cancer MGC803 cells were treated with IN and /or CDDP. Proliferation of the cells was detected by using MTT assay. Apoptosis of cells was measured by using fluorescence staining, and cell cycle kinetics by flow cytometry.

RESULTS: Both IN and CDDP were able to restrain the proliferation and induce apoptosis of the cells. There was dose-dependent and time-dependent cell proliferation induced by IN. High concentration of CDDP (10 mg/L) had also the time-effect, but a low dose of CDDP (0.1, 1 mg/L) did not. The percentage of apoptotic cells did not changed after 24h incubation with a low dose of CDDP. There also existed good dose-dependent and time-dependent effects when every concentration of CDDP combined with moderate dose IN (200 mmol/L). Low dose CDDP with IN had the similar effect to that of high dose CDDP alone.

CONCLUSION: IN and CDDP have the synergistic action when they work together on gastric cancer cell line MGC-803 and perhaps IN can antagonize the chemo-resistance of gastric cancer to other chemical drugs.

[Role of cyclooxygenase-2 in the pathogenesis of chronic liver diseases]

Cyclooxygenase (COX) is a crucial enzyme in the biosynthesis of prostaglandins. There are two COX isoforms: COX-1 is constitutively expressed in a number of cell types and is involved in the homeostatic functions of prostaglandins, whereas COX-2 is inducible by a variety of proinflammatory stimuli, such as cytokines and lipopolysaccharide. In the liver, COX-2 and prostaglandins production has been implicated in hepatic regeneration, liver matrix remodeling and portal hypertension. In animal models of alcoholic-induced liver disease has been demonstrated its relation with necro-inflammatory activity. In viral hepatitis, hepatocellular COX-2 expression was observed and associated with fibrosis progression. More interestingly it has been the demonstration of COX-2 role in the development of hepatocellular carcinoma and cholangiocarcinoma, such in experimental models as in human samples. It has also been demonstrated that COX-2 was implicated in carcinogenesis through apoptosis inhibition and increased proliferation of human tumor cells. Experimental evidences show that selective pharmacologic inhibition of COX-2 could be useful in chemoprevention of primary liver tumors.

Inhibitory effects of celecoxib on proliferation of human liver and gastric carcinoma cells in vitro

AIM: To study the inhibitory effects of celecoxib on proliferation of human hepatoma SMMC-7721 cells and gastric cancer SGC-7901 cells in vitro.

METHODS: The two carcinoma cells were cultured with celecoxib at various concentrations(0, 20, 40, 80, 160 and 320 mmol/L). Growth suppression was detected with MTT colorimetric assay, cell apoptotic alterations were evaluated by transmission electron microscopy(TEM), and quantity of Cox-2 was evaluated by cytochemical staining.

RESULTS: The inhibition of proliferation on two carcinoma cells was observed(49.1% and 42.9% by 320 mmol/L celecoxib). The inhibitory effect was dose-dependent. Apoptotic cells were observed under transmission electron microscope. The different quantities of Cox-2 protein in cells were observed by cytochemical staining.

CONCLUSION: Celecoxib inhibits proliferation, induces apoptosis of human two carcinoma cells in vitro, and the effects have close relation to the quantities of Cox-2 protein in cells.

Apoptosis induced by mitomycin with sulindac on human gastric cancer cell SGC7901

AIM: To investigate the effects of mitomycin (MMC) with sulindac on the cell viability, apoptotic induction and expression of apoptosis-related gene Bcl-2 and cyclooxygenase-2 (COX-2) in gastric adenocarcinoma cell SGC7901.

METHODS: Human gastric cancer SGC7901 cells were divided into three groups, sulindac, MMC and sulindac with MMC. After treatment with drugs, cell viability was examined by MTT assay. Flow cytometry was used for the cell cycle distribution and apoptotic rates. The morphology of the cells was observed under light microscope and interactive laser cytometer. The expression of COX-2, Bcl-2 was determined by the immunocytochemical method.

RESULTS: After exposure for 12 h to three kinds of drugs, gastric cancer cells SGC7901 presented some morphologic features of apoptosis, including cell shrinkage, nuclear condensation, DNA fragmentation, formation of apoptotic bodies. The effects of growth inhibition were more obvious in cotreatment group with MMC and sulindac than MMC group. The apoptotic rates in cotreated cells and MMC-treated cells at 24 h after treatment were 12.0% and 7.2%, respectively. After exposure for 24 h to MMC, upregulation of COX-2 and Bcl-2 protein expression was noted, meanwhile, in cotreatment group, the levels of COX-2 were downregulated but the expression of Bcl-2 gene was not changed significantly.

CONCLUSION: MMC-induced apoptosis is reduced by upregulating the expression of COX-2 and Bcl-2 genes. MMC combined with sulindac can suppress growth of gastric cancer cells through induction of apoptosis which may be mediated by downregulation of apoptosis-related Bcl-2 gene and COX-2 gene.

Serum from rabbit orally administered cobra venom inhibits growth of implanted hepatocellular carcinoma cells in mice

AIM: To investigate the inhibitory effect of serum preparation from rabbits orally administered cobra venom (SRCV) on implanted hepatocellular carcinoma (HCC) cells in mice.

METHODS: An HCC cell line, HepA, was injected into mice to prepare implanted tumors. The animals (n = 30) were divided randomly into SRCV, 5-fluorouracil (5-FU), and distilled water (control) groups. From the second day after transplantation, 20 mg/kg 5-FU was administered intraperitoneally once a day for 9 d. SRCV (1000 mg/kg) or distilled water (0.2 mL) was given by gastrogavage. Tumor growth inhibition was described by the inhibitory rate (IR). Apoptosis was detected by transmission electron microscopy (TEM), flow cytometry (FCM), and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL). Student’s t-test was performed for statistical analysis.

RESULTS: The tumor growth was inhibited markedly by SRCV treatment compared to that in the control group (P < 0.01). The treatment resulted in a significant increase in the apoptotic rate of cancer cells by the factors of 10.5% ± 2.4% and 20.65% ± 3.2% as demonstrated through TUNEL and FCM assays, respectively (P < 0.01). The apoptotic cells were also identified by characteristic ultrastructural features.

CONCLUSION: SRCV can inhibit the growth of implanted HepA cells in mice, and the apoptosis rate appears to elevate during the process.

Dietary alpha-linolenic acid reduces COX-2 expression and induces apoptosis of hepatoma cells

Fatty acid synthetase (FAS) is overexpressed in various tumor tissues, and its inhibition and/or malonyl-CoA accumulation have been correlated to apoptosis of tumor cells. It is widely recognized that both omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) depress FAS expression in liver, although epidemiological and experimental reports attribute antitumor properties only to omega-3 PUFA. Therefore, we investigated whether lipogenic gene expression in tumor cells is differently regulated by omega-6 and omega-3 PUFAs. Morris hepatoma 3924A cells were implanted subcutaneously in the hind legs of ACI/T rats preconditioned with high-lipid diets enriched with linoleic acid or alpha-linolenic acid. Both-high lipid diets depressed the expression of FAS and acetyl-CoA carboxylase in tumor tissue, this effect correlating with a decrease in the mRNA level of their common sterol regulatory element binding protein-1 transcription factor. Hepatoma cells grown in rats on either diet did not accumulate malonyl-CoA. Apoptosis of hepatoma cells was induced by the alpha-linolenic acid-enriched diet but not by the linoleic acid-enriched diet. Therefore, in this experimental model, apoptosis is apparently independent of the inhibition of fatty acid synthesis and of malonyl-CoA cytotoxicity. Conversely, it was observed that apoptosis induced by the alpha-linolenic acid-enriched diet correlated with a decrease in arachidonate content in hepatoma cells and decreased cyclooxygenase-2 expression.

Differentiation of hepatocellular carcinoma SMMC-7721 cell line induced by Chinese medicine recipe Weichangan

AIM

To observe the differentiation in hepatocellular carcinoma cell line induced by Chinese medicine recipe Weichangan.

METHODS

Weichangan, contrasted by the retinoic acid and distilled water, was made by using serum pharmacological method. The inhibition on the growth of SMMC-7721 cell line by Weichangan was observed through the method of MTT and Alamar Blue. Radioimmunoassay was applied to determine the concentration of a-fetoprotein and albumin secreted by the incubated cells. Western blot method was used to detect the mutant p53, p16 and p21 protein expression in SMMC-7721 cell line.

RESULTS

MTT assay showed both Weichangan and serum retinoic acid had inhibiting effect on the proliferation of human hepatocellular carcinoma SMMC-7721 cell line. Weichangan reached its maximal inhibition effect after 48 hours, while the effect of retinoic acid decreased gradually after 48 hours. Alamar Blue method showed that significant decrease was found in serum Weihangan after 16 hours compared with that in the control. After 32 hours, the decrease induced by Alamar Blue was more significant than that in cells incubated with serum Weichangan compared with those incubated in serum retinoic acid, indicating the gradual and durable action of Weichangan recipe. The decreased amount (11.4±1.4 mg/L vs 17.2±1.1 mg/L, P =0.036) of a-fetoprotein and increased amount (0.40±0.02 mg/L vs 0.29±0.01 mg/L, P =0.043) of albumin were found in the cells incubated in serum Weichangan. Western blot method showed decreased expression of p53 protein and increased expression of p16 and p21 protein in cells incubated in serum Weichangan.

CONCLUSION

The results suggest that Weichangan inhibits the growth of SMMC-7721 cell line and induces the differentiation in this hepatocellular carcinoma cell line. The effect on p53, p16 and p21 may be the mechanisms of Weichangan in inducing the differentiation of this cell lines.

Establishment of apoptotic model induced by hydroxyapatite nanoparticles in human hepatoma cell line BEL-7402

AIM

To establish an apoptotic model induced by hydroxyapatite (HAP) nanoparticles in human hepatoma cell line in vitro in order to explore the mechanism of nanoparticles-induced apoptosis.

METHODS

The selected human hepatoma cell line BEL-7402 was treated with HAP nanoparticles at different concentrations and for various durations of time. Growth suppression was evaluated by MTT method. Apoptosis-related alterations in morphology and biochemistry were ascertained under cytochemical staining (Hoechst 33 258), transmission electron microscopy (TEM), and DNA agarose gel electrophoresis. Flow cytometry (FCM) was used to investigate the apoptotic rate.

RESULTS

HAP nanoparticles inhibited the growth of hepatoma cells in a dose and time-dependent manner. After BEL-7402 cells were treated with 50-200 mg/L HAP nanoparticles for 48 h, apoptosis with nuclear chromatin condensation and fragmentation as well as cell shrinkage were observed using fluorescent staining and TEM. DNA ladder could be demonstrated on DNA electrophoresis. By FCM analysis, the apoptotic rates at concentrations of 0 mg/L, 50 mg/L,75 mg/L, 100 mg/L, 150 mg/L, 200 mg/L were 2.2%, 20.3%, 25.3%, 29.8%, 45.1% and 53.1%, respectively. Cell apoptosis began approximately at 12h after administration of 50 mg/L and peaked at 48 h following treatment. The rates at 12, 24, 36, and 48 h were 2.7%, 3.5%, 6.3%, and 21.4%, respectively.

CONCLUSION

HAP nanoparticles not only inhibit proliferation but also induce apoptosis of human hepatoma cell line BEL-7402 in vitro. The successful establishment of this model will help further explore the molecular mechanism of hepatoma cells apoptosis.

Effects of hydroxyapatite nanoparticles on proliferation and apoptosis of human hepatoma BEL-7402 cells

AIM: To study the effect of hydroxyapatite (HAP) nanoparticles on human hepatoma cell line BEL-7402 in vitro.

METHODS: The human hepatoma cell line BEL-7402 was cultured and treated with HAP nanoparticles at various concentrations. Growth suppression was detected with MTT colorimetric assay, cell apoptotic alterations were evaluated by cytochemical staining (Hoechst 33258), transmission electron microscopy (TEM), and flow cytometry (FCM).

RESULTS: HAP nanoparticles inhibited the growth of hepatoma cells in a dose-dependent manner, with IC₅₀ values of 29.30 mg/L. Treated with 50-200 mg/L HAP nanoparticles for 48 h, BEL-7402 cells apoptosis with nuclear chromatin condensation and fragmentation as well as cell shrinkage and the formation of apoptotic bodies were observed under cytochemical staining and transmission electron microscopy. FCM analysis showed hypodiploid peaks on histogram, the apoptotic rates at the concentrations of 50, 75, 100, 150 and 200 mg/L of HAP nanoparticles were 20.35 ± 2.23%, 25.35 ± 1.92%, 29.34 ± 4.61%, 44.92 ± 3.78% and 53.64 ± 3.49%, respectively, which were all significantly higher than that of control group 2.23 ± 0.14%. There was a significant correlation between HAP nanoparticle concentration and apoptotic rate (r = 0.994, P < 0.01).

CONCLUSION: HAP nanoparticles not only inhibit proliferation but also induce apoptosis of human hepatoma cell line BEL-7402 in vitro.

Peroxisome proliferator-activated receptor gamma ligands inhibit cell growth and induce apoptosis in human liver cancer BEL-7402 cells

AIM: To investigate the characteristics of PPAR gamma ligands induced apoptosis in liver cancer cells.

METHODS: The effects of ligands for each of the PPAR gamma ligands on DNA synthesis and cell viability were examined in BEL-7402 liver cancer cells. Apoptosis was characterized by Hochest33258 staining, DNA fragmentation, TUNEL and ELISA, and cell cycle kinetics by FACS. Modulation of apoptosis related caspases expression by PPAR gamma ligands was examined by Western blot.

RESULTS: PPARgamma ligands, 15-deoxy-^{12, 14}-prostaglandin J2 (15d-PGJ2) and troglitazone (TGZ), suppressed DNA synthesis of BEL-7402 cells. Both 15d-PGJ2 and TGZ induced BEL-7402 cell death in a dose dependent manner, which was associated with an increase in fragmented DNA and TUNEL-positive cells. At concentrations of 10 and 30 µM, 15d-PGJ₂ or troglitazone increased the proportion of cells with G₀/G₁ phase DNA content and decreased those with S phase DNA content. There was no significant change in the proportion of cells with G₂/M DNA content. The activities of Caspases-3, -6, -7 and -9 were increased by 15d-PGJ2 and TGZ treatment, while the activity of Caspase 8 had not significantly changed.

CONCLUSION: The present results suggest the potential usefulness of PPAR gamma ligands for chemoprevention and treatment of liver cancers.

Effects of cyclooxygenase-2 antisense vector on proliferation of human cholan-giocarcinoma cells

AIM

To transfect antisense vector of human COX-2 gene into COX-2 highly expressing cholangiocarcinoma cell line QBC939 and to explore its biological activities and role in carcinogenesis.

METHODS

QBC939 cells were transfected with antisense vector of human COX-2 gene using LipoVecTM transfecting technique. Transfected cells were selected with G418; COX-2 mRNA was examined by using reverse transcription polymerase chain reaction (RT-PCR) and COX-2 protein expression was detected by immunocytochemistry using isozyme selective antibodies. The proliferative status of transfected cells was measured by using methabenzthiazuron (MTT) assay; Cell cycle and apoptosis was analyzed by using flow cytometry (FCM).

RESULTS

RT-PCR showed a lower COX-2 mRNA level in transfected cells and immunocytochemistry showed weaker COX-2 protein expression in transfected cells. The proliferative index of the transfected cells decreased significantly(P<0.01), the percentage of S phase decreased remarkably in transfected cells(9.27±1.91%) compared with that in QBC939 cells without transfection (16.35±2.87%)(P<0.05), and the percentage of G0/G1 phase increased remarkably in transfected cells (75.16±4.13%) compared with that in QBC939 cells without transfection (57.31±10.16%)(P<0.05). Transfection with antisense vector of human COX-2 gene had no significant influence on the apoptosis in QBC939 cells (P>0.05).

CONCLUSION

Transfection with antisense vector of human COX-2 gene is able to inhibit the proliferation of human cholangiocarcinoma QBC939 cells.

PPARγ pathway activation results in apoptosis and COX-2 inhibition in HepG2 cells

AIM: To investigate whether troglitazone (TGZ), the peroxisome proliferator-activated receptor (PPAR) gamma ligand, can induce apoptosis and inhibit cell proliferation in human liver cancer cell line HepG2 and to explore the molecular mechanisms.

METHODS: [3-(4, 5)-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide (MTT), [³H] Thymidine incorporation, Hochest33258 staining, DNA ladder, enzyme-linked immunosorbent assay (ELISA), RT-PCR, Northern and Western blotting analyses were employed to investigate the effect of TGZ on HepG2 cells and related molecular mechanisms.

RESULTS: TGZ was found to inhibit the growth of HepG2 cells and to induce apoptosis. During the process, the expression of COX-2 mRNA and protein and Bcl-2 protein was down-regulated, while that of Bax and Bak proteins was up-regulated, and the activity of caspase-3 was elevated. Furthermore, the level of PGE₂ was decreased transiently after 12 h of treatment with 30 μM troglitazone.

CONCLUSION: TGZ inhibits cell proliferation and induces apoptosis in HepG2 cells, which may be associated with the activation of caspase-3-like proteases, down-regulation of the expression of COX-2 mRNA and protein, Bcl-2 protein, the elevation of PGE₂ levels, and up-regulation of the expressions of Bax and Bak proteins.

Celecoxib inhibits proliferation and induces apoptosis via prostaglandin E2 pathway in human cholangiocarcinoma cell lines

AIM: To evaluate the roles and mechanisms of celecoxib in inducing proliferation inhibition and apoptosis of human cholangiocarcinoma cell lines.

METHODS: Cyclooxygenase-2-overexpressing human cholangiocarcinoma cell line QBC939 and cyclooxygenase-2-deficient human cholangiocarcinoma cell line SK-CHA-1 were used in the present study. The anti-proliferative effect was measured by methabenzthiazuron (MTT) assay; apoptosis was determined by transferase-mediated dUTP nick end labeling (TUNEL) detection and transmission electron microscopy (TEM). Cell cycle was analyzed by flow cytometry (FCM). The PGE₂ levels in the supernatant of cultured cholangiocarcinoma cells were quantitated by enzyme-linked immunoabsordent assay (ELISA).

RESULTS: Celecoxib suppressed the production of PGE₂ and inhibited the growth of QBC939 cells. Celecoxib at 10, 20, and 40 μmol/L inhibited PGE₂ production by 26%, 58%, and 74% in QBC939 cells. The PGE₂ level was much lower constitutively in SK-CHA-1 cells (18.6 ± 3.2) compared with that in QBC939 (121.9 ± 5.6) cells (P < 0.01) and celecoxib had no significant influence on PGE₂ level in the SK-CHA-1 cells. The PGE₂ concentration in SK-CHA-1 cells also reduced but not significantly after treatment with celecoxib. The PGE₂ concentration in SK-CHA-1 cells was (16.5 ± 2.9) ng/well, (14.8 ± 3.4) ng/well, (13.2 ± 2.0) ng/well and (12.6 ± 3.1) ng/well respectively, when pre-treated with 1 μmol/L, 10 μmol/L, 20 μmol/L and 40 μmol/L of celecoxib for 48 h (P > 0.05, vs control). The anti-proliferation effect of celecoxib (20 μmol/L) on QBC939 cells was time-dependent, it was noticeable on day 2 (OD490 = 0.23 ± 0.04) and became obvious on day 3 (OD₄₉₀ = 0.31 ± 0.07) to day 4 (OD490 = 0.25 ± 0.06), and the OD₄₉₀ in the control group (day 1) was 0.12 ± 0.03 (P < 0.01, vs control). The anti-proliferation effect of celecoxib could be abolished by the addition of 200 pg/mL PGE₂. The proliferation of SK-CHA-1 cells was inhibited slightly by celecoxib, the cell density OD490 in the presence of celecoxib and in control group was 0.31 ± 0.04 and 0.42 ± 0.03 respectively on day 2 (P > 0.05), 0.58 ± 0.07 and 0.67 ± 0.09 respectively on day 3 (P > 0.05), and 0.71 ± 0.08 and 0.78 ± 0.06 respectively on day 4 (P > 0.05). Celecoxib induced proliferation inhibition and apoptosis by G₁-S cell cycle arrest: the percentage of QBC939 cells in G₀-G₁phase after treatment with 40 μmol/L (74.6 ± 66.21) and 20 μmol/L (68.63 ± 4.36) celecoxib increased significantly compared with control cells (54.41 ± 5.12, P < 0.01). The percentage of SK-CHA-1 cells in G₀-G₁ phase after treatment with various concentrations of celecoxib didn't change significantly compared with control cells. The TUNEL index was much higher in QBC939 cells treated with 20 μmol/L celecoxib for 2 d (0.063 ± 0.018) and for 4 d (0.102 ± 0.037) compared with control cells (0.017 ± 0.004, P < 0.01).

CONCLUSION: The current in vitro study indicates that inhibition of proliferation and induction of apoptosis in human cholangiocarcinoma cells by cyclooxygenase-2 specific inhibitor celecoxib may involve in COX-dependent mechanisms and PGE₂pathway. Celecoxib as a chemopreventive and chemotherapeutic agent might be effective primarily on COX-2-expressing cholangiocarcinoma.

Biological characteristics of HCC by ultrasound-guided aspiration biopsy and its clinical application

AIM: To probe the pathological biological characteristics of hepatocellular carcinoma (HCC) by the ultrasound-guided aspiration biopsy and assess the clinical application value of this method.

METHODS: The biopsy and DNA analysis by flow cytometry (FCM) were taken in 46 cases with HCC nodules, including 26 cases and 20 cases with nodules ≤ 3 cm and > 3 cm in diameters respectively, and 12 cases with intrahepatic benign hyperplastic nodules. They were taken in 22 cases of 46 cases with HCC before and after the therapy. Fine-needles and automatic histological incised biopsy needles were used. The fresh biopsy tissue was produced into the single cell suspension, which was sent for DNA detection and ratio analysis of cell period. The ratio of each DNA period of cell proliferation of each group was calculated and compared with each other. The DNA aneuploid (AN) and apoptosis cell peak were observed and their percentages were calculated.

RESULTS: The ratios of S and G₂/M periods of DNA, which reflect cell hyperproliferation, in the group with HCC tumors > 3 cm in diameter were markedly higher than those of the group with HCC nodules ≤ 3 cm in diameter and the group with the benign hyperplastic nodules (P < 0.01 except A:B of S period, P < 0.05). The ratios of the middle group were also apparently higher than those of the latter group (P < 0.01). The ratio of DNA AN of 46 cases with HCC nodules was 34.8% (16/46). None of the cases with the intrahepatic hyperplastic nodules appeared AN. The DNA AN appeared more apparently with the growth of the tumors. The AN ratio of the group with tumors > 3 cm in diameter was 55% (11/20), markedly higher than that of the group with tumors ≤ 3 cm in diameter which was 19.2% (5/26) (P < 0.01). The FCM DNA analysis of 22 specimens of hepatic carcinoma tissue before therapy showed that the aneuploid peaks appeared in 5 cases (22.7%). The ratio of G₁ period rose after therapy while the S period and G₂/M ratios fell (P < 0.01). The aneuploid peak disappeared in the 5 cases after the therapy, while the apoptosis peaks in 12 cases (54.5%) appeared.

CONCLUSION: Addition to supply the information of the pathological morphology of the tumor, the ultrasound-guided fine-needle aspiration tissue could be sent for FCM DNA analysis to comprehend its pathological biological characteristics. This can not only provide the clinic the reliable information about the occurrence, development, diagnosis, curative effect and prognosis of tumors but also supply biological information for clinic to choose therapeutic schemes.

Effects of adenovirus-mediated human cox-2 antisense RNA on synthesis of DNA and proteins in esophgeal carcinoma cell line

AIM

To construct the recombinant adenovirus encoding human cox-2 antisense RNA, and to investigate its effect on synthesis of DNA and proteins in esophgeal carcinoma cell line EC9706.

METHODS

The shuttle plasmid encoding antisense cox-2 was constructed by cloning cox-2 cDNA fragment in the reverse direction into the pHCMVSP1A. Then the plasmid pJM17 and the shuttle plasmid were cotransferred into 293 cells with lipofectamine for homologouserecombinantion to acquire recombinant adenovirus confirmed by PCR. The expressions of cox-2 in esophgeal carcinoma cell line EC9706 cells were evaluated, and its effects on cell proliferation were determined by cell growth rate, ³H-TdR and ³H-Leucine incorporation.

RESULTS

The recombinant adenovirus encoding antisense cox-2 fragment ad-AShcox-2 was obtained with the titer of 0.86±10¹² PFU/ml. Ad-AShcox-2 can reduce the expression of cox-2, and inhibit cell growth rate and cause cellular death. Meanwhile, The efficiency of ³H-TdR and ³H-Leucine incorporation was significant lower than that in the control group at 48, 72, 96 hours (q_{48 h} = 16.36 vs 16.36, q_{72 h} = 39.07 vs 19.90 , q_{96 h}= 54.80 vs 30.33; P<0.001).

CONCLUSION

Reducing the expression of cox-2 may inhibit the proliferation of esophageal cancer cells through inhibiting the synthesis of DNA and protein.

Laminin induces the expression of cytokeratin 19 in hepatocellular carcinoma cells growing in culture

AIM: To study the abnormal cytokeratin (CK) expression, emergence of CK19 with or without CK7, in liver parenchymal cells and the role of laminin (LN), a basement membrane protein, in this process.

METHODS: Six hepatocellular carcinoma (HCC) cell lines were examined for different CKs, LN and its receptor by immunocytochemistry and Western blotting. Double immunofluorescent reaction, laser-scanning confocal microscopy and an in vitro induction procedure were used to demonstrate the role of LN in regulating CK19 expression in these cells.

RESULTS: Immunoreactivities for CK8, CK18, CK7 and the receptor for LN were observed in all the six HCC cell lines examined. However, CK19 was merely found in four of the six cell lines, and was in any case associated with LN expression. Laser-scanning confocal microscopy demonstrated the concomitant presence of these two molecules in most of the positive cells. In the two HCC cell lines, originally negative for CK19, addition of LN to the culture medium resulted in an induction of CK19 in a dose-dependent manner. Both the artificially induced and the intrinsic production of CK19 were completely blocked by an antibody to LN.

CONCLUSION: LN can induce expression of CK19 in HCC cells in vitro, providing direct evidence for our hypothesis that the abnormal hepatocytic CK19 expression in situ is due to pathologic LN deposition.

Bile from a patient with anomalous pancreaticobiliary ductal union promotes the proliferation of human cholangiocarcinoma cells via COX-2 pathway

AIM: To explore the effects of COX-2 gene in the proliferative activity induced by bile from anomalous pancreaticobiliary ductal union (APBDU) on human cholangiocarcinoma cell line.

METHODS: Bile sample from APBDU and normal bile sample were used for this study. The proliferative effect of bile was measured by methabenzthiazuron (MTT) assay; COX-2 mRNA was examined by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). Cell cycle was analyzed by flow cytometry (FCM), and the PGE₂ levels in the supernatant of cultured cholangiocarcinoma cells were quantitated by enzyme-linked immunoabsordent assay (ELISA).

RESULTS: Bile from APBDU can significantly promote the proliferation of human cholangiocarcinoma QBC939 cells compared with normal bile (P = 0.005) and up-regulated remarkably their COX-2 mRNA expression (P = 0.004). The proliferative activity of APBDU bile can be abolished by addition of cyclooxygenase-2 specific inhibitor celecoxib.

CONCLUSION: Bile from APBDU can promote the proliferation of human cholangiocarcinoma QBC939 cells via COX-2 pathway.

Nimesulide inhibits proliferation via induction of apoptosis and cell cycle arrest in human gastric adenocarcinoma cell line

AIM

To evaluate the potential role of Nimesulide, a selective COX-2 inhibitor, in proliferation and apoptosis of gastric adenocarcinoma cells SGC7901.

METHODS

Cell counts and MTT assay were used to quantify the influence of Nimesulide in the proliferation of SGC7901 cells. Transmission electron microscopy and flow cytometry were used to observe the induction of Nimesulide the apoptosis of SGC7901 cells and influence in the distribution of cell cycle. The expression of P27(kip1) protein was observed by immunocytochemical staining.

RESULTS

SGC-7901 Cells treated with Nimesulide at various concentrations exhibited a profound dose- and time-dependent reduction in the proliferation rate over the 72 h test period. The highest survival rate of the cells was 78.7 %, but the lowest being 22.7 %. Nimesulide induced apoptosis of the cells in a dose-dependent and non-linear manner and increased the proportion of cells in the G(0)/G(1) phase and decreased the proportion in the S and G(2)/M phase of the cell cycle. Meanwhile, Nimesulide could up-regulate the expression of P27(kip1) protein.

CONCLUSION

The induction of apoptosis and cell cycle arrest are both anti-proliferative responses that likely contribute to the antineoplastic action of nimesulide on SGC-7901 cells. The up-regulation of P27(kip1) gene may contribute to the accumulation of these cells in the G(0)/G(1) phase following treatment with Nimesulide. Selective COX-2 inhibitor may be a new channel of the chemoprevention and chemotherapy for gastric carcinoma.

Experimental study on ultrasound-guided intratumoral injection of “Star-99” in treatment of hepatocellular carcinoma of nude mice

AIM: To investigate the anti-cancer effect and the immunological mechanism of ultrasound-guided intratumoral injection of Chinese medicine “Star-99” in hepatocellular carcinoma (HCC) of nude mice.

METHODS: Twenty-eight human hepatocellular carcinoma SMMC-7721 transplanted nude mice, 14 of hypodermically implanted and 14 of orthotopic liver transplanted, were randomly divided into three groups of which 14 mice with Star-99, and 7 with ethanol and saline respectively. Ten days after the transplantation the medicines were injected into the tumors of all the nude mice once every 5 d. After 4 injections the nude mice were killed. The diameters of three dimension of the tumors were measured by high frequency ultrasound before and after the treatment and the tumor growth indexes^* (TGI) were calculated. Radioimmunoassay was used to detect the serum levels of interleukin-2 (IL-2) and tumor necrosis factor (TNF)-alpha. The tumor tissues were sent for flow cytometry (FCM) DNA analysis. Apoptotic cells were visualized by TUNEL assay. All the experiments were carried out by double blind method.

RESULTS: The TGI of Star-99 group (0.076 ± 0.024) was markedly lower than that of the saline group (4.654 ± 1.283) (P < 0.01). It also seemed to be lower than that of the ethanol group (0.082 ± 0.028), but not significantly different (P > 0.05). Serum levels of IL-2 and TNF-α were markedly higher than those of ethanol group and saline groups (P < 0.05). The mean apoptotic index (AI: percentage of TUNEL signal positive cells) in Star-99 group (48.98% ± 5.09%) was significantly higher than that of the ethanol group (11.95% ± 2.24%) and the saline group (10.48% ± 3.85%) (P < 0.01). FCM DNA analysis showed that the appearance rate of the apoptosis peak in Srar-99 group was 92.9%, markedly higher than that of the ethanol group (14.3%) and the saline group (0.0%) (P < 0.01). Correlation (r = 0.499, P < 0.05) was found between AI and serum level of TNF-α.

CONCLUSION: Star-99 has an effect on the elevation of the serum levels of IL-2 and TNF-α. It indicates that Star-99 has the function of enhancing the cellular immunity and inducing cancer cell apoptosis. The correlation between AI and serum level of TNF-α indicates that the elevation of the serum of TNF-α induced by Star-99 may be an important factor in the promotion of the hepatic cancer cell apoptosis. Star-99 has strong effects on the inhibition and destruction of cancer cells. Its curative effect is as good as ethanol. Its major mechanisms can be as follows: (1) it increases the serum levels of IL-2 and TNF-α and triggers cellular immunity. (2) It can induce cancer cells apoptosis, the effective mechanism of the Star-99 is different from that of the ethanol. The mechanisms of triggering the immunologic function of the organism and inducing cell apoptosis are, of particular significance. This study will provide a new pathway of drug administration and an experimental basis for the treatment of HCC with Chinese herbal, and the study of Star-99 in the treatment of tumor is of profound significance with good prospects.

Correlation of COX-2 expression and clinicopathological features of colorectal cancer

AIM: To investigate the expression of COX-2 on different stages of colorectal cancer and the correlation between the expression of COX-2 and its clinicopathological features.

METHODS: The expression of COX-2 was determined by immunohistochemical staining in seventy-six surgical specimens of colorectal cancer (late stage 44 and early stage 32), 33 adenomas and 18 normal colonic mucosal tissues were biopsied endocscopically. The correlation of COX-2 with the survival rate was evaluated with Kaplan-Meier survival curves and Cox proportional hazards regression.

RESULTS: The degree of expression of COX-2 was categorized into 4 grades ranged from "-" to "+++", the expression grades in series in normal colonic mucosal tissues was 83.3%, 16.7%, 0%, 0%, respectively; that in adenomas was 12.1%, 42.4%, 36.4%, 9.1%, respectively. The difference of the expression of COX-2 between late stage and early stage of colorectal cancer, and that between the late stage of cancer and adenoma were statistically significant (P < 0.01); however, no significant difference in the expression of COX-2 between early stage of cancer and adenoma was observed. A significant difference in the survival curves between low COX-2 expression group and high COX-2 expression group was showed by Kaplan-Meier survival analysis (P < 0.05). Cox proportional hazards regression indicated that the correlation of the expression of COX-2 with the poor long-term prognosis was existed with a hazard ratio of 2.665 unadjusted for other variables (P < 0.05); the expression of COX-2 was an independent risk factor for poor prognosis.

CONCLUSION: The expression of COX-2 is gradually up-regulated in the evolution of normal epithelium to adenoma or from early stage to advanced stage of colorectal cancer. The expression of COX-2 is an independent risk factor of poor prognosis for postoperative patients with advanced colorectal cancer.

Expression of cyclooxygenase-2 in pancreatic cancer and its correlation with p53

AIM: To investigate the expressions of COX-2 and p53 in human pancreatic cancer and their correlation with biological behaviors of pancreatic cancer.

METHODS: The expressions of COX-2 and p53 in 51 specimens of human pancreatic ductal adenocarcinoma and 11 specimens of normal tissues adjacent human pancreatic ductal adenocarcinoma were detected with immunohistochemistry by Envision.

RESULTS: The detectable rate of COX-2 and p53 in pancreatic ductal adenocarcinoma were 74.5% and 60.8%, respectively; but none in adjacent normal tissues. The expression of COX-2 was significantly associated with the clinical stages and metastasis status of lymph nodes (P = 0.022, 0.036), but not with histological grade (P = 0.152). The expression of p53 was significantly correlated with the lymph node metastasis status (P = 0.035), but not with their histological grades and clinical stages (P = 0.131, 0.078). There was a significant correlation between the expression of COX-2 and p53 (r = 0.452, P = 0.001). Conditions such as age, sex, tumor size and location had no relation with expression of COX-2 or p53.

CONCLUSION: The cooperation of COX-2 and p53 may play a pivotal role in the carcinogenesis and the progression in pancreatic cancer. They may provide new targets for the therapy of pancreatic cancer.

Expression of cyclooxygenase-2 and clinicopathologic features in human gastric adenocarcinoma

AIM: To study the expression of cyclooxygenase-2 (COX-2) gene in gastric cancer and the relationship between COX-2 expression and clinicopathologic features of gastric cancer.

METHODS: With reference to the expression of β-actin gene, COX-2 mRNA level was examined in cancerous tissues and adjacent noncancerous mucosa from 33 patients by semiquantitative reverse transcription- polymerase chain reaction (RT-PCR). Quantitation of relative band Adj volume counts was performed using molecular Analyst for windows software. The COX-2 index was determined from the band Adj volume counts ratio of COX-2 to constitutively expressed actin.

RESULTS: The COX-2 index in gastric carcinoma was significantly higher than that in normal mucosa (0.5966 ± 0.2659 vs 0.2979 ± 0.171, u = 5.4309, P < 0.01). Significantly higher expression of COX-2 mRNA was also observed in patients with lymph node involvement than that in those without (0.6775 ± 0.2486 vs 0.4105 ± 0.2182, t = 2.9341, P < 0.01). Furthermore, the staging in the UICC TNM classification significantly correlated with COX-2 overexpression (F = 3.656, P < 0.05), the COX-2 index in stage III and IV was significantly higher than those in stage I and II (q = 3.2728 and q = 3.4906, P < 0.05). The COX-2 index showed no correlation with patient抯 age, sex, blood group, tumor location, gross typing, depth of invasion, differentiation, and the greatest tumor dimension (P > 0.05).

CONCLUSION: Expression of COX-2 mRNA in gastric carcinoma was significantly higher, which may enhance lymphatic metastasis in patients with gastric carcinoma. The staging in the UICC TNM classification was significantly correlated with COX-2 over-expression. COX-2 may contribute to progression of tumor in human gastric adenocarcinoma.

Proliferative activity of bile from congenital choledochal cyst patients

AIM: To explore the potential carcinogenicity of bile from congenital choledochal cyst (CCC) patients and the mechanism of the carcinogenesis in congenital choledochal cyst patients.

METHODS: 20 bile samples from congenital choledochal cyst patients and 10 normal control bile samples were used for this study. The proliferative effect of bile was measured by using Methabenzthiazuron (MTT) assay; Cell cycle and apoptosis were analyzed by using flow cytometry (FCM), and the PGE₂ levels in the supernatant of cultured cholangiocarcinoma cells were quantitated by enzyme-linked immunoabsordent assay (ELISA).

RESULTS: CCC bile could significantly promote the proliferation of human cholangiocarcinoma QBC939 cells compared with normal bile (P = 0.001) and negative control group (P = 0.002), and the proliferative effect of CCC bile could be abolished by addition of cyclooxygenase-2 specific inhibitor celecoxib (20 µM). The QBC939 cells proliferative index was increased significantly after treated with 1% bile from CCC patient (P = 0.008) for 24 h, the percentage of S phase (29.48 ± 3.27)% was increased remarkably (P < 0.001) compared with normal bile (11.72 ± 2.70)%, and the percentage of G0/G1 phase (54.19 ± 9.46)% was decreased remarkably (P = 0.042) compared with normal bile (69.16 ± 10.88)%, however, bile from CCC patient had no significant influence on apoptosis of QBC939 cells (P = 0.719).

CONCLUSION: Bile from congenital choledochal cyst patients can promote the proliferation of human cholangiocarcinoma QBC939 cells via COX-2 and PGE₂ pathway.

Apoptosis of hepatoma cells SMMC-7721 induced by Ginkgo biloba seed polysaccharide

AIM: To study the apoptosis of hepatoma cells SMMC-7721 induced by polysaccharide isolated from Ginkgo biloba seed.

METHODS: Ginkgo biloba seed polysaccharide (GBSP) was isolated by ethanol fractionation of Ginkgo biloba seed and purified by Sephadex G-200 chromatography. The purity of GBSP was verified by reaction with iodine-potassium iodide and ninhydrin and confirmed by UV spectrophotometer, cellulose acetate membrane electrophoresis and Sepharose 4B gel filtration chromatography. The Scanning Electron Microscope (SEM) and Flow Cytometry (FCM) were used to examine the SMMC-7721 cells with and without GBSP treatment at 500 mg/mL for 36 h.

RESULTS: GBSP product obtained was of high purity with the average molecular weight of 1.86 × 10⁵. Quantitative analysis of SMMC-7721 cells in vitro with FCM showed that the percentages of G2-M cells without and with GBSP treatment were 17.01% ± 1.28% and 11.77% ± 1.50% (P < 0.05), the debris ratio of the cells were 0.46% ± 0.12% and 0.06% ± 0.06% (P < 0.01), and the apoptosis ratio of cells was 3.84% ± 0.55% and 9.13% ± 1.48% (P < 0.01) respectively. Following GBSP treatment, microvilli of SMMC-7721 cells appeared thinner and the number of spherical cells increased markedly. Most significantly, the apoptosis bodies were formed on and around the spherical cells treated with GBSP.

CONCLUSION: GBSP could potentially induce the apoptosis of SMMC-7721 cells.

The effects of vitamin E succinate on the expression of c-jun gene and protein in human gastric cancer SGC-7901 cells

AIM

To investigate the effects of vitamin E succinate (VES) on the expression of c-jun gene and protein in human gastric cancer SGC-7901 cells.

METHODS

After SGC-7901 cells were treated with VES at different doses (5,10,20 mg x L(-1)) at different time, reverse transcription-PCR technique was used to detect the level of c-jun mRNA; Western Blot was applied to measure the expression of c-jun protein.

RESULTS

After the cells were treated with VES at 20 mg x L(-1) for 3 h, the expression rapidly reached its maximum that was 3.5 times of UT control (P<0.01). The level of c-jun mRNA was also increased following treatment of VES for 6 h. However,the expression after treatment of VES at 5 mg x L(-1) for 24 h was 1.6 times compared with UT control (P<0.01). Western blot analysis showed that the level of c-jun protein was obviously elevated in VES-treated SGC-7901 cells at 20 mg x L(-1) for 3 h. The expression of c-jun protein was gradually increased after treatment of VES at 20 mg x L(-1) for 3, 6, 12 and 24 h, respectively, with an evident time-effect relationship.

CONCLUSION

The levels of c-jun mRNA and protein in VES-treated SGC-7901 cells were increased in a dose- and time-dependent manner; the expression of c-jun was prolonged by VES, indicating that c-jun is involved in VES-induced apoptosis in SGC-7901 cells.