The clinical value of rapidly detecting urinary exosomal lncRNA RMRP in bladder cancer with an RT-RAA-CRISPR/Cas12a method.

BACKGROUND AND AIMS: Bladder cancer (BCa) is a highly aggressive malignancy of the urinary system. Timely detection is imperative for enhancing BCa patient prognosis. MATERIALS AND METHODS: This study introduces a novel approach for detecting long non-coding RNA (lncRNA) Mitochondrial RNA Processing Endoribonuclease (RMRP) in urine exosomes from BCa patients using the reverse transcription recombinase-aided amplification (RT-RAA) and clustered regularly interspaced short palindromic repeats and associated Cas12a proteins (CRISPR/Cas12a) technique. Various statistical methods were used to evaluate its diagnostic value for BCa. RESULTS: The specificity of urine exosomal RMRP detection for BCa diagnosis was enhanced by using RT-RAA combined with CRISPR/Cas12a. The testing process duration was reduced to 30 min, which supports rapid detection. Moreover, this approach allows the identification of target signals in real-time using blue light, facilitating immediate detection. In clinical sample analysis, this methodology exhibited a high level of diagnostic efficacy. This was evidenced by larger area under the curve values with receiver operating characteristic curve analysis compared with using traditional RT-qPCR methods, indicating superior diagnostic accuracy and sensitivity. Furthermore, the combined analysis of RMRP expression in urine exosomes detected by RT-RAA-CRISPR/Cas12a and NMP-22 expression may further enhance diagnostic accuracy. CONCLUSIONS: The RT-RAA-CRISPR/Cas12a technology is a swift, sensitive, and uncomplicated method for nucleic acid detection. Because of its convenient and non-invasive sampling approach, user-friendly operation, and reproducibility, this technology is very promising for automated detection and holds favorable application possibilities within clinical environments.

CXCL14 as a Key Regulator of Neuronal Development: Insights from Its Receptor and Multi-Omics Analysis.

CXCL14 is not only involved in the immune process but is also closely related to neurodevelopment according to its molecular evolution. However, what role it plays in neurodevelopment remains unclear. In the present research, we found that, by crossbreeding CXCL14+/- and CXCL14-/- mice, the number of CXCL14-/- mice in their offspring was lower than the Mendelian frequency; CXCL14-/- mice had significantly fewer neurons in the external pyramidal layer of cortex than CXCL14+/- mice; and CXCL14 may be involved in synaptic plasticity, neuron projection, and chemical synaptic transmission based on analysis of human clinical transcriptome data. The expression of CXCL14 was highest at day 14.5 in the embryonic phase and after birth in the mRNA and protein levels. Therefore, we hypothesized that CXCL14 promotes the development of neurons in the somatic layer of the pyramidal cells of mice cortex on embryonic day 14.5. In order to further explore its mechanism, CXCR4 and CXCR7 were suggested as receptors by Membrane-Anchored Ligand and Receptor Yeast Two-Hybrid technology. Through metabolomic techniques, we inferred that CXCL14 promotes the development of neurons by regulating fatty acid anabolism and glycerophospholipid anabolism.

Engineering Neutrophil Immunomodulatory Hydrogels Promoted Angiogenesis.

Timely restoration of blood supply following ischemia is critical to rescue damaged tissue. However, clinical efficacy is hampered by the inflammatory response after ischemia. Whether inflammation fine tunes the angiogenesis and the function of blood vessels via the heterogeneity of neutrophils remain poorly understood. Herein, the objective of this work is to incorporate the growth factors secreted by neutrophils into a porous gelatin methacrylate (GelMA) hydrogel, which subsequently is used as a novel regenerative scaffold with defined architecture for ischemia. We demonstrate that anti-inflammatory neutrophils (N2-polarized neutrophils) play an important role in promoting the migration of human umbilical vein endothelial cells (HUVECs) and formation of capillary-like networks in vitro. More importantly, vascular anastomosis can be achieved by modulating the neutrophils to N2 phenotype. In addition, N2-polarized composite hydrogel scaffolds can regulate inflammation, maintain the survival of exogenous cells, and promote angiogenesis in vivo. Notably, the composite hydrogel scaffolds promote neovascularization during exogenous introduction of endothelial cells by anastomosis. Taken together, this study highlights N2-polarized neutrophils composite hydrogels can achieve vascularization rapidly by regulating inflammation and promoting vascular anastomosis. This work lays the foundation for research into the treatment of ischemia and may inspire further research into novel treatment options.

Fatty acid feedstocks enable a highly efficient glyoxylate-TCA cycle for high-yield production of ß-alanine.

Metabolic engineering to produce tricarboxylic acid (TCA) cycle-derived chemicals is usually associated with problems of low production yield and impaired cellular metabolism. In this work, we found that fatty acid (FA) feedstocks could enable high-yield production of TCA cycle-derived chemicals, while maintaining an efficient and balanced metabolic flux of the glyoxylate-TCA cycle, which is favorable for both product synthesis and cell growth. Here, we designed a novel synthetic pathway for production of ß-alanine, an important TCA cycle-derived product, from FAs with a high theortecial yield of 1.391 g/g. By introducing panD, improving aspA, and knocking out iclR, glyoxylate shunt was highly activated in FAs and the yield of ß-alanine reached 0.71 g/g from FAs, much higher than from glucose. Blocking the TCA cycle at icd/sucA/fumAC nodes could increase ß-alanine yield in a flask cultivation, but severely reduced cell growth and FA utilization during fed-batch processes. Replenishing oxaloacetate by knocking out aspC and recovering fumAC could restore the growth and lead to a titer of 35.57 g/l. After relieving the oxidative stress caused by FA metabolism, ß-alanine production could reach 72.05 g/l with a maximum yield of 1.24 g/g, about 86% of the theoretical yield. Our study thus provides a promising strategy for the production of TCA cycle-derived chemicals.

Effect of joint mobilization techniques for primary total knee arthroplasty: Study protocol for a randomized controlled trial.

BACKGROUND: Total knee arthroplasty (TKA) has become the most preferred procedure by patients for the relief of pain caused by knee osteoarthritis. TKA patients aim a speedy recovery after the surgery. Joint mobilization techniques for rehabilitation have been widely used to relieve pain and improve joint mobility. However, relevant randomized controlled trials showing the curative effect of these techniques remain lacking to date. Accordingly, this study aims to investigate whether joint mobilization techniques are valid for primary TKA. METHODS/DESIGN: We will manage a single-blind, prospective, randomized, controlled trial of 120 patients with unilateral TKA. Patients will be randomized into an intervention group, a physical modality therapy group, and a usual care group. The intervention group will undergo joint mobilization manipulation treatment once a day and regular training twice a day for a month. The physical modality therapy group will undergo physical therapy once a day and regular training twice a day for a month. The usual care group will perform regular training twice a day for a month. Primary outcome measures will be based on the visual analog scale, the knee joint Hospital for Special Surgery score, range of motion, surrounded degree, and adverse effect. Secondary indicators will include manual muscle testing, 36-Item Short Form Health Survey, Berg Balance Scale function evaluation, Pittsburgh Sleep Quality Index, proprioception, and muscle morphology. We will direct intention-to-treat analysis if a subject withdraws from the trial. DISCUSSION: The important features of this trial for joint mobilization techniques in primary TKA are randomization procedures, single-blind, large sample size, and standardized protocol. This study aims to investigate whether joint mobilization techniques are effective for early TKA patients. The result of this study may serve as a guide for TKA patients, medical personnel, and healthcare decision makers. TRIAL REGISTRATION: It has been registered at http://www.chictr.org.cn/showproj.aspx?proj=15262 (Identifier:ChiCTR-IOR-16009192), Registered 11 September 2016. We also could provide the correct URL of the online registry in the WHO Trial Registration. http://apps.who.int/trialsearch/Trial2.aspx?TrialID=ChiCTR-IOR-16009192.

Energy metabolism regulated by HDAC inhibitor attenuates cardiac injury in hemorrhagic rat model.

A disturbance of energy metabolism reduces cardiac function in acute severe hemorrhagic patients. Alternatively, adequate energy supply reduces heart failure and increases survival. However, the approach to regulating energy metabolism conductive to vital organs is limited, and the underlying molecular mechanism remains unknown. This study assesses the ability of histone deacetylase inhibitors (HDACIs) to preserve cardiac energy metabolism during lethal hemorrhagic injury. In the lethally hemorrhagic rat and hypoxic myocardial cells, energy metabolism and heart function were well maintained following HDACI treatment, as evident by continuous ATP production with normal cardiac contraction. Valproic acid (VPA) regulated the energy metabolism of hemorrhagic heart by reducing lactate synthesis and protecting the mitochondrial ultrastructure and respiration, which were attributable to the inhibition of lactate dehydrogenase A activity and the increased myeloid cell leukemia-1 (mcl-1) gene expression, ultimately facilitating ATP production and consumption. MCL-1, the key target of VPA, mediated this cardioprotective effect under acute severe hemorrhage conditions. Our results suggest that HDACIs promote cardioprotection by improving energy metabolism during hemorrhagic injury and could therefore be an effective strategy to counteract this process in the clinical setting.

Chidamide Inhibits Aerobic Metabolism to Induce Pancreatic Cancer Cell Growth Arrest by Promoting Mcl-1 Degradation.

Pancreatic cancer is a fatal malignancy worldwide and urgently requires valid therapies. Previous research showed that the HDAC inhibitor chidamide is a promising anti-cancer agent in pancreatic cancer cell lines. In this study, we elucidate a probable underlying anti-cancer mechanism of chidamide involving the degradation of Mcl-1. Mcl-1 is frequently upregulated in human cancers, which has been demonstrated to participate in oxidative phosphorylation, in addition to its anti-apoptotic actions as a Bcl-2 family member. The pancreatic cancer cell lines BxPC-3 and PANC-1 were treated with chidamide, resulting in Mcl-1 degradation accompanied by induction of Mcl-1 ubiquitination. Treatment with MG132, a proteasome inhibitor reduced Mcl-1 degradation stimulated by chidamide. Chidamide decreased O2 consumption and ATP production to inhibit aerobic metabolism in both pancreatic cancer cell lines and primary cells, similar to knockdown of Mcl-1, while overexpression of Mcl-1 in pancreatic cancer cells could restore the aerobic metabolism inhibited by chidamide. Furthermore, chidamide treatment or Mcl-1 knockdown significantly induced cell growth arrest in pancreatic cancer cell lines and primary cells, and Mcl-1 overexpression could reduce this cell growth inhibition. In conclusion, our results suggest that chidamide promotes Mcl-1 degradation through the ubiquitin-proteasome pathway, suppressing the maintenance of mitochondrial aerobic respiration by Mcl-1, and resulting in inhibition of pancreatic cancer cell proliferation. Our work supports the claim that chidamide has therapeutic potential for pancreatic cancer treatment.

Synergistic antitumor activity of gemcitabine combined with triptolide in pancreatic cancer cells.

Pancreatic cancer is a fatal human malignancy associated with an exceptionally poor prognosis. Novel therapeutic strategies are urgently required to treat this disease. In addition to immunosuppressive activity, triptolide possesses strong antitumor activity and synergistically enhances the antitumor activities of conventional chemotherapeutic drugs in preclinical models of pancreatic cancer. The present study investigated the antitumor effects of triptolide in pancreatic cancer cells, either in combination with gemcitabine, or alone. The pancreatic cancer BxPC-3 and PANC-1 cell lines were treated with triptolide, which resulted in time- and dose-dependent growth arrest. When incorporated into a sequential schedule, triptolide synergistically increased gemcitabine-induced cell growth inhibition and apoptosis, in addition to the cooperative regulation of B-cell lymphoma 2 family proteins and loss of mitochondrial membrane potential. Furthermore, triptolide enhanced gemcitabine-induced S phase arrest and DNA double-strand breaks, possibly through checkpoint kinase 1 suppression. The results of the present study suggest that triptolide has therapeutic potential for the treatment of pancreatic cancer, particularly when administered in combination with gemcitabine.

Valproic acid-mediated myocardial protection of acute hemorrhagic rat via the BCL-2 pathway.

BACKGROUND: Hemorrhage is a major cause of morbidity and mortality among trauma patients. The pathophysiologic changes following acute severe hemorrhage and tissue hypoxia lead to an imbalance of protein acetylation. Histone deacetylase inhibitors (HDACIs) were reported to restore the acetylation imbalance and serve as potential drugs for treating severe hemorrhage. However, the molecular mechanism of HDACI-mediated cytoprotection remains unclear. In this study, we examined the myocardial protective effects and respective mechanism of the HDACI valproic acid (VPA) administered during hemorrhagic and hypoxic stress in vivo and in vitro. METHODS: In vivo, the therapeutic effect of VPA was evaluated in acute severe hemorrhagic rats, and the expressions of BCL-2 signal pathway molecules were observed in rat heart tissues. To explore the molecular mechanism of VPA-mediated myocardial protection, a cobalt chloride (CoCl2)-induced hypoxia model of rat H9c2 cardiomyoblasts was applied to mimic hypoxic injury raised by acute hemorrhage. RESULTS: VPA administration significantly improved the 4-hour survival rate of hemorrhagic animals from 55% to 100% and protected H9c2 cells against CoCl2-induced hypoxic injury at a dose of between 12.5 µM and 100 µM. Increased expression of BCL-2 messenger RNA was observed following VPA treatment in the heart tissues of hemorrhagic rats (approximately 4.9-fold) and in H9c2 cells that survived CoCl2-induced hypoxia (approximately 4.9-fold). Western blot analysis showed a concomitant increase in BCL-2 protein expression and Akt phosphorylation following VPA treatment. The cytoprotective activity of VPA was diminished by triciribine-mediated inhibition of Akt activation and by silencing of BCL-2 gene expression. CONCLUSION: These findings suggest that VPA protects myocardial cells from hemorrhagic and hypoxic stress through the Akt/BCL-2 survival pathway, indicating a potential use of HDACIs for acute severe hemorrhage treatment.

Activating Na+-K+ ATPase: a potential cardioprotective therapy during early hemorrhagic shock.

Cell volume and resting potential are heavily affected by the activity of Na+-K+ ATPase (NKA, Na+-K+ pump), an essential membrane protein that regulates plasma K+ and Na+ levels. It is generally accepted that the ineffective perfusion of body tissues inhibits NKA activity and that NKA activity and heart failure are closely related. Recently, research has proven that the activation of NKA provides significant cardioprotection against ischemic injury. Based on these data, we propose that NKA stimulation could attenuate the development of heart arrhythmia during the early phase of hemorrhagic shock.

Optimization and establishment of RNA interference-mediated knockdown of the progestagen-associated endometrial protein gene in human metastatic melanoma cell lines.

Progestagen­associated endometrial protein (PAEP), also termed glycodelin, is a 28­kDa glycoprotein of the lipocalin superfamily that is expressed in a variety of tumors, including gynecological tumors, lung cancer and melanoma. To determine the biological functions of the PAEP gene in tumor development and progression, the production of transient and stable PAEP knockdown cell models is required. In the present study, RNA interference technology was used to silence PAEP gene expression in melanoma and transfection was screened for and the conditions were optimized using fluorescence microscopy, flow cytometry, qPCR and western blot analysis. The results of the present study showed that the transient transfection of melanoma cells with 100 nmol/l PAEP siRNA or lentiviral PAEP small hairpin RNA (shRNA) [multiplicity of infection (MOI), 100 pfu/cell] efficiently knocked down target gene expression. To establish stable PAEP knockdown cell lines, melanoma cells were infected with a low MOI (10 pfu/cell) of lentiviral particles expressing PAEP shRNA. Following puromycin screening, the PAEP gene knockdown efficiency was demonstrated to be >80% in 624­Mel and 624.38­Mel cell lines, which was validated by western blot analysis. Therefore, melanoma cell lines with stable knockdown of PAEP were successfully established and may be used as effective cell models to study the biological functions of the PAEP gene in melanoma.

Chidamide, a novel histone deacetylase inhibitor, synergistically enhances gemcitabine cytotoxicity in pancreatic cancer cells.

Pancreatic cancer is a lethal human malignancy with an extremely poor prognosis and urgently requires new therapies. Histone deacetylase inhibitors (HDACIs) represent a new class of anticancer agents and have shown promising antitumor activities in preclinical models of pancreatic cancer. In this study, we sought to determine the antitumor effects of a novel HDACI, chidamide (CS055), in pancreatic cancer cells alone or in combination with gemcitabine. Treatments of BxPC-3 or PANC-1 pancreatic cancer cell lines with chidamide resulted in dose- and time-dependent growth arrest, accompanied by induction of p21 expression. When combined in a sequential schedule, chidamide synergistically enhanced gemcitabine-induced cell growth arrest and apoptosis, accompanied by cooperative downregulation of Mcl-1 and loss of mitochondrial membrane potential (ΔΨm). Chidamide enhanced gemcitabine-induced DNA double-strand breaks and S phase arrest, and abrogated the G2/M cell cycle checkpoint, potentially through suppression of CHK1 expression. Our results suggest that chidamide has a therapeutic potential for treating pancreatic cancer, especially in combination with gemcitabine.

[Effects of conjugated linoleic acid on the expression of critical enzymes of linoleic acid metabolism in tumor cell].

OBJECTIVES: To study the effects of c9,t11-conjugated linoleic acid (c9,t11-CLA) on critical enzymes of linoleic acid metabolism in stomach granular cell (SGC-7901). METHODS: SGC-7901 was treated with c9,t11-CLA by 200, 100, 50 or 25 micromol/L for 24 hours. The effects of c9,t11-CLA on the cell proliferation was measured by monotetrazolium and the expression of Delta6-desaturase, Delta5-desaturase, COX-1, COX-2, 5-LOX mRNA were measured by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: At a concentration of 200, 100, 50, or 25 micromol/L, c9,t11-CLA suppressed the proliferation of SGC-7901 by 54.3%, 20.5%, 10.5% and 2.93%. The c9,t11-CLA might decrease the expression of COX-2 mRNA, and increase the expression of Delta6-desaturase and COX-1 in SGC-7901, but might not affect Delta5-desaturase and 5-LOX. CONCLUSION: The effects of c9,t11-CLA on the COX and Delta6-desaturase might play an important role in mediating the ability of c9,t11-CLA as to inhibiting the proliferation of tumor cells, and the anti-cancer activity by c9,t11-CLA might be associated with the linoleic acid metabolism.

Effects of c9,t11-conjugated linoleic acid on adhesion of human gastric carcinoma cell line SGC-7901.

AIM: To investigate the effect of c9,t11-conjugated linoleic acid (c9,t11-CLA) on the adhesion of human gastric carcinoma cell line (SGC-7901). METHODS: SGC-7901 cells were at first treated with different concentrations (25, 50, 100, 200 micromol/L) of c9,t11-CLA and 1 mL/L ethanol (as a negative control) for 24 h. Using adhesion assay and Western blot, we investigated the ability of SGC-7901 cells to adhere to intracellular matrix and examined the expression of E-cadherin (ECD), alpha-catenin, intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) in these cells. RESULTS: The attachment rate to laminin of SGC-7901 cells treated with different concentrations of c9,t11-CLA (0, 25, 50, 100, and 200 micromol/L) was 100.0+/-3.3, 95.7+/-4.0, 89.2+/-4.6, 87.9+/-6.1, and 65.9+/-5.8, respectively. The attachment rate to fibronectin was 100.0+/-4.7, 96.8+/-3.8, 94.5+/-4.1, 76.5+/-4.3, and 61.8+/-4.8, respectively. The attachment rate to Matrigel was 99.9+/-6.6, 91.4+/-6.8, 85.5+/-7.4, 79.3+/-5.6, and 69.6+/-5.1, respectively. Besides, c9,t11-CLA could increase the level of ECD and alpha-catenin, and decrease the level of ICAM-1 and VCAM-1 in SGC-7901 cells. CONCLUSION: c9,t11-CLA can reduce the adhesion of human gastric carcinoma cells to laminin, fibronectin and Matrigel. c9,t11-CLA can increase the level of ECD and alpha-catenin, and decrease the level of ICAM-1 and VCAM-1 in human gastric carcinoma cells.

[Effect of apoptosis in human mammary cancer (MCF-7) cells induced by cis9, t11-conjugated linoleic acid].

OBJECTIVE: To determine the effect of cell apoptosis induced by c9, t11-conjugated linoleic acid was investigated in human mammary cancer cells (MCF-7), which were treated with various c9, t11-CLA concentrations (25, 50, 100 and 200 mumol/L), with a negative control. METHODS: In this study, the methods of the curve of cell growth, cell apoptosis detecting in fluorescent and electronic microscope and flow cytometry, and expression of p53 protein were employed. RESULTS: The cell growth of MCF-7 cells was inhibited by c9, t11-CLA. Eight day after treatment with various concentrations of c9, t11-CLA, as mentioned above, the inhibition rates were -6.0%, 45.2%, 99.0% and 99.4%, respectively. Apoptotic cells of morphology from MCF-7 cells treated by different concentrations of c9, t11-CLA were observed by fluorescent and electronic microscope and the frequency of apoptosis in MCF-7 cells by flow cytometry showed increasingly with concentrations of c9, t11-CLA increased. While the expression of p53 protein in MCF-7 cells was decreased with the doses of c9, t11-CLA increased. CONCLUSION: c9, t11-CLA can induce the effect of apoptosis in MCF-7 cells and its may be one of mechanisms for the inhibitory effect of c9, t11-CLA in human cancer cells.

[The effects of conjugated linoleic acid on the ability of murine macrophage in killing tumor cells].

OBJECTIVE: To study the effects of c9,t11-conjugated linoleic acid on the killing ability of macrophage to B16-MB cells in C57 mice and explore its possible mechanism. METHODS: The five levels of CLA was designed as 0, 25, 50, 75, 100 micro mol/L. After macrophage was treated with CLA for 24 h, the killing ability of macrophage on B16-MB cells was evaluated by MTT, The expression of C57 mice macrophage cytokine IL-6, TNF-alpha and iNOS mRNA was detected by RT-PCR. The expression of Erk protein was examined by Western Blot assay. RESULTS: The inhibitory effect of macrophage on tumor cell depend on the treatment of the increased c9,t11-CLA level, at the same time, the expression of IL-6, TNF-alpha and iNOS mRNA increased, the expression of Erk decreased with the elevating dose of CLA. CONCLUSIONS: c9,t11-CLA could increase the killing ability of macrophage in mice to B16-MB cells, and it was associated with induction of IL-6, TNF-alpha and iNOS mRNA expression. We speculate that antitumor ability of CLA may be associated with taking part in body immune regulation action, and the effects of CLA on the killing ability of murine macrophage to B16-MB cells was not associated with the MAPKErk pathway.

Inhibitory effects of c9, t11-conjugated linoleic acid on invasion of human gastric carcinoma cell line SGC-7901.

AIM: To investigate the effect of c9, t11-conjugated linoleic acid (c9, t11-CLA) on the invasion of human gastric carcinoma cell line and its possible mechanism of preventing metastasis. METHODS: Using reconstituted basement membrane invasion, chemotaxis, adhesion, PAGE substrate zymography and RT-PCR assays, we analyzed the abilities of invasion, direct migration, adhesion of intracellular matrix, as well as the activity of type IV collagenase and expression of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 mRNA in SGC-7901 cells which were treated with gradually increased concentrations (25, 50, 100 and 200 micromol/L) of c9, t11-CLA for 24 h. RESULTS: At the concentrations of 200 micromol/L, 100 micromol/L and 50 micromol/L, c9,t11-CLA suppressed the invasion of SGC-7901 cells into the reconstituted basement membrane by 53.7 %, 40.9 % and 29.3 %, respectively, in comparison with the negative control. Only in the 200 micromol/L c9,t11-CLA group, the chemotaxis of SGC-7901 cells was inhibited by 16.0 % in comparison with the negative control. C9,t11-CLA also could inhibit the adhesion of SGC-7901 cells to laminin, fibronectin and Matrigel, increase the expression of TIMP-1 and TIMP-2 mRNA, and reduce type IV collagenase activities in the serum-free medium supernatant of SGC-7901 cells. CONCLUSION: c9,t11-CLA can inhibit the invasion of SGC-7901 cells at multiple procedures in tumor metastasis cascade, which may be associated with the induction of TIMP-1 and TIMP-2 mRNA expression.

[The effects of conjugated linoleic acid on the expression of invasiveness and metastasis-associated gene of human gastric carcinoma cell line].

OBJECTIVES: To study the effects of c9,t11-conjugated linoleic acid (c9,t11-CLA) on invasive ability of human gastric carcinoma cell line (SGC-7901) and to explore its possible mechanism. METHODS: Reconstituted basement membrane invasion assay was used to evaluate invasive ability of cancer cells. Expression of TIMP-1, TIMP-2 and nm23-H(1) mRNA was measured by reverse transcription polymerase chain reaction (RT-PCR) in SGC-7901 cells. RESULTS: At the concentrations of 200 micromol/L, 100 micromol/L and 50 micromol/L, c9,t11-CLA suppressed their reconstituted basement membrane invasion of SGC-7901 by 53.7%, 40.9% and 29.3%, respectively. c9,t11-CLA could induce the expression of TIMP-1, TIMP-2 and nm23-H(1) mRNA in SGC-7901 cells. CONCLUSIONS: The invasion of SGC-7901 cells could be inhibited by c9,t11-CLA through reconstituted basement membrane. Anti-invasion action of c9,t11-CLA might be associated with induction of expression of TIMP-1, TIMP-2 and nm23-H(1) mRNA in tumor cells.

Inhibition of conjugated linoleic acid on mouse forestomach neoplasia induced by benzo (a) pyrene and chemopreventive mechanisms.

AIM: To explore the inhibition of conjugated linoleic acid isomers in different purity (75 % purity c9,t11-, 98 % purity c9,t11- and 98 % purity t10,c12-CLA) on the formation of forestomach neoplasm and chemopreventive mechanisms. METHODS: Forestomach neoplasm model induced by B(a)P in KunMing mice was established. The numbers of tumor and diameter of each tumor in forestomach were counted; the mice plasma malondialdehyde (MDA) were measured by TBARS assay; TUNEL assay was used to analyze the apoptosis in forestomach neoplasia and the expression of MEK-1, ERK-1, MKP-1 protein in forestomach neoplasm were studied by Western Blotting assay. RESULTS: The incidence of neoplasm in B(a)P group, 75 % purity c9, t11-CLA group, 98 % purity c9,t11-CLA group and 98 % purity t10, c12-CLA group was 100 %, 75.0 %(P>0.05), 69.2 % (P<0.05) and 53.8 % (P<0.05) respectively and the effect of two CLA isomers in 98 % purity on forestomach neoplasia was significant; CLA showed no influence on the average tumor numbers in tumor-bearing mouse, but significantly decreased the tumor size, the tumor average diameter of mice in 75 % purity c9,t11-CLA group, 98 % purity c9,t11-CLA group and 98 % purity t10, c12-CLA group was 0.157+/-0.047 cm, 0.127+/-0.038 cm and 0.128+/-0.077 cm (P<0.05) and 0.216+/-0.088 cm in B(a)P group; CLA could also significantly increase the apoptosis cell numbers by 144.00+/-20.31, 153.75+/-23.25, 157.25+/-15.95(P<0.05) in 75 % purity c9,t11-CLA group, 98 % purity c9,t11-CLA group and 98 % purity t10,c12-CLA group (30.88+/-3.72 in BP group); but there were no significant differences between the effects of 75 % purity c9,t11-CLA and two isomers in 98 % purity on tumor size and apoptotic cell numbers; the plasma levels of MDA in were increased by 75 % purity c9,t11-CLA, 98 % purity c9,t11-CLA and 98 % purity t10,c12-CLA. The 75 % purity c9,t11-CLA showed stronger inhibition; CLA could also inhibit the expression of ERK-1 protein and promote the expression of MKP-1 protein, however no influence of CLA on MEK-1 protein was observed. CONCLUSION: Two isomers in 98 % purity show stronger inhibition on carcinogenesis. However, the inhibitory mechanisms of CLA on carcinogenesis is complicated, which may be due to the increased mice plasma MDA, the inducing apoptosis in tumor tissues. And the effect of CLA on the expression of ERK-1 and MKP-1 may be one of the mechanisms of the inhibition of CLA on the tumor.