Novel combined endoscopic and laparoscopic surgery for advanced T2 gastric cancer: Two case reports.

BACKGROUND: The standard treatment for advanced T2 gastric cancer (GC) is laparoscopic or surgical gastrectomy (either partial or total) and D2 lymphadenectomy. A novel combined endoscopic and laparoscopic surgery (NCELS) has recently been proposed as a better option for T2 GC. Here we describe two case studies demonstrating the efficacy and safety of NCELS. CASE SUMMARY: Two T2 GC cases were both resected by endoscopic submucosal dissection and full-thickness resection and laparoscopic lymph nodes dissection. This method has the advantage of being more precise and minimally invasive compared to current methods. The treatment of these 2 patients was safe and effective with no complications. These cases were followed up for nearly 4 years without recurrence or metastasis. CONCLUSION: This novel method provides a minimally invasive treatment option for T2 GC, and its potential indications, effectiveness and safety needs to be further evaluated in controlled studies.

Nickel-Catalyzed Arylcarbamoylation of Alkenes of N-(o-Iodoaryl)acrylamides with Nitroarenes via Reductive Aminocarbonylation: Facile Synthesis of Carbamoyl-Substituted Oxindoles.

Nickel-catalyzed arylcarbamoylation reactions of alkenes of N-(o-haloaryl)acrylamides with CO and nitroarenes via reductive aminocarbonylation to produce carbamoyl-substituted oxindoles with an all-carbon quaternary stereogenic center are presented. Starting with N-(o-haloaryl)acrylamides, simple CO, and inexpensive nitroarenes and using a Ni catalyst, a dinitrogen-based ligand, a Zn reductant, a TMSCl additive, and a base system, this protocol enables the synthesis of various carbamoyl-substituted oxindoles and allows the efficient late-stage derivatization of valuable molecules.

2,6-Bis(4-meth-oxy-phen-yl)-1,4-dithiine.

The title mol-ecule, C18H16O2S2, reveals crystallographic twofold rotation symmetry (with both S atoms lying on the axis) and one half-mol-ecule defines an asymmetric unit. The dithiine ring is in a boat conformation. The aromatic ring and the C=C bond are nearly coplanar, with small torsion angles of -171.26 (19) and 8.5 (3)°. The two S-C bond lengths [1.7391 (19) and 1.7795 (18) Å] are shorter than single C-S bonds and longer than analogous C=S double bonds, which indicates a certain degree of conjugation between the lone pair on the S atom and π electrons of the C=C bond. The crystal packing only features van der Waals inter-actions.

In vivo effect of triptolide combined with glycyrrhetinic acid on rat cytochrome P450 enzymes.

Triptolide (TP) is a major active component in Tripterygium root, but its therapeutic window was very narrow due to its severe multi-organ toxicity. In this work, the effect of TP combined with glycyrrhetic acid (GA) on mRNA expression and activity of four cytochrome P450 (CYP) enzymes in rat liver was studied after intragastric administration of TP (0.05, 0.3 and 0.6 mg x kg(-1) x day(-1)) and TP (0.6 mg x kg(-1) x day(-1)) combined with GA (30 mg x kg(-1) x day(-1)) for 7 consecutive days. Compared with the control, the high dose of TP significantly up-regulated the mRNA expression levels of CYP2E1, 1A2, 3A1 and 2C11, the co-administration of TP and GA further up-regulated the mRNA expression levels of CYP3A1, 2C11 and 2E1 as compared with the high dose of TP. Meanwhile, TP at high dose and combined with GA significantly increased CYP3A-associated testosterone 6beta-hydroxylation activity (2.2-fold and 4.1-fold, respectively) as compared with the control. Because TP is mainly metabolized by CYP3A2 in male rats, the present work indicated that TP-induced increase of CYP3A activity might be an important reason for the rapidly metabolic clearance of TP in rat liver, and GA can reduce the hepatotoxicity of TP by promoting its hepatic metabolic clearance. Furthermore, the results also suggest that the drug interactions might be occurred when TP and GA were co-administered with other CYP3A substrate drug.

Aberrant expression of Cx43 is associated with the peritoneal metastasis of gastric cancer and Cx43-mediated gap junction enhances gastric cancer cell diapedesis from peritoneal mesothelium.

The process of peritoneal metastasis involves the diapedesis of intra-abdominal exfoliated gastric cancer cells through the mesothelial cell monolayers; however, the related molecular mechanisms for this process are still unclear. Heterocellular gap-junctional intercellular communication (GJIC) between gastric cancer cells and mesothelial cells may play an active role during diapedesis. In this study we detected the expression of connexin 43 (Cx43) in primary gastric cancer tissues, intra-abdominal exfoliated cancer cells, and matched metastatic peritoneal tissues. We found that the expression of Cx43 in primary gastric cancer tissues was significantly decreased; the intra-abdominal exfoliated cancer cells and matched metastatic peritoneal tissues exhibited increasing expression compared with primary gastric cancer tissues. BGC-823 and SGC-7901 human gastric cancer cells were engineered to express Cx43 or Cx43T154A (a mutant protein that only couples gap junctions but provides no intercellular communication) and were co-cultured with human peritoneal mesothelial cells (HPMCs). Heterocellular GJIC and diapedesis through HPMC monolayers on matrigel-coated coverslips were investigated. We found that BGC-823 and SGC-7901 gastric cancer cells expressing Cx43 formed functional heterocellular gap junctions with HPMC monolayers within one hour. A significant increase in diapedesis was observed in engineered Cx43-expressing cells compared with Cx43T154A and control group cells, which suggested that the observed upregulation of diapedesis in Cx43-expressing cells required heterocellular GJIC. Further study revealed that the gastric cancer cells transmigrated through the intercellular space between the mesothelial cells via a paracellular route. Our results suggest that the abnormal expression of Cx43 plays an essential role in peritoneal metastasis and that Cx43-mediated heterocellular GJIC between gastric cancer cells and mesothelial cells may be an important regulatory step during metastasis. Finally, we observed that the diapedesis of exfoliated gastric cancer cells through mesothelial barriers is a viable route of paracellular migration.

Identification of in vivo and in vitro metabolites of triptolide by liquid chromatography-tandem mass spectrometry.

Triptolide, a major active constituent of Tripterygium wilfordii Hook F, has multiple pharmacological activities. In this work, a rapid, sensitive and specific liquid chromatography coupled to an ion trap mass spectrometer (MS) with electrospray ionization (ESI) interface has been developed for identification of triptolide and some of its metabolites in rat urine after oral administration of a single dose (0.6 mg/kg) of triptolide to healthy rats, as well as some metabolites in vitro after incubation with rat liver microsome (RLM) and rat intestinal flora, respectively. All samples were separated on a reversed-phase C18 column using a mobile phase of acetonitrile/water (70:30, v/v) and detected by an on-line MS(n) detector. Identification and structural elucidation of the selected metabolites were performed by comparing their full scan MS(n) spectra with those of the parent drug. In this paper we identified ten metabolites in rat urine, four metabolites in RLM incubation solution and one metabolite in rat intestinal flora incubation solution, after drug administration. The metabolic reactions of triptolide that we observed in vivo were hydrolysis reaction, hydroxylation reaction, and the conjugate reaction with sulfate, glucuronide and GSH, respectively. The in vitro metabolic reactions of triptolide observed were hydrolysis and hydroxylation reactions.

In vitro metabolism of glycyrrhetic acid by human cytochrome P450.

Licorice root has been frequently used as antitode in traditional Chinese medicine. As the main active component of Licorice root, glycyrrhetic acid (GA) is mainly metabolized in liver. This study was designed to investigate the in vitro metabolism of GA by human liver microsomes (HLM) and human recombinant cytochrome P450 (CYP) isoforms. The results indicated that GA was metabolized mainly by CYP3A4. The K(m), V(max) and CL(int) of GA in HLM were 18.6 micromol x L(-1), 4.4 nmol x mg(-1) (protein) x min(-1) and 0.237 mL x mg(-1) (protein) x min(-1), respectively. At concentration up to 50 micromol x L(-1), GA inhibited CYP2C19, CYP2C9 and CYP3A4 enzyme activities with the inhibitory potencies up to 50%.

Changes of organic anion transporter MRP4 and related nuclear receptors in human obstructive cholestasis.

BACKGROUND: Hepatic multidrug resistance-associated protein 4 (Mrp4) levels are low, but increase markedly in rodent cholestatic liver. Nuclear receptors (NRs) are essential for regulating Mrp4 expression in cholestasis models. However, information about MRP4 and related NRs, including constitutive androstane receptor (CAR), pregnane X receptor (PXR), and retinoic X receptor-α (RXRα), is relatively lacking in human obstructive cholestasis. We collected liver samples from patients with obstructive cholestasis or without liver disease and investigated the expression of MRP4 and NRs CAR, PXR, and RXRα by semi-quantitative RT-PCR, Western blot and immunostaining assays. RESULTS: MRP4 mRNA/protein levels were markedly increased in obstructive cholestasis. Concentration of serum total bile acids (TBA) was significantly correlated with MRP4 protein in cholestasis samples (P < 0.01). PXR and RXRα mRNA/protein levels were significantly increased in obstructive cholestasis. CAR mRNA levels were unchanged while protein levels were markedly induced in obstructive cholestasis. There was a statistically positive correlation between MRP4 mRNA and CAR protein (P < 0.05), suggesting that CAR may activate transcription of MRP4 genes by its nuclear translocation. CONCLUSION: Hepatic MRP4 levels were dramatically induced in human obstructive cholestasis, which may reduce liver injury by increasing efflux of toxic bile acids from hepatocytes into blood.

Expression and significance of Cx43 and E-cadherin in gastric cancer and metastatic lymph nodes.

Connexin 43(Cx43) and E-cadherin are concurrently expressed in many tumors and were ever classified as tumor suppressors in primary tumors (PT), whereas recent studies showed that these two proteins played specific roles in tumor metastasis. The aim of our study is to determine the expression of Cx43 and E-cadherin in primary gastric tumors (PTs) and matched metastatic lymph nodes (MLNs) and to explore the clinical and pathological implications of expression of these proteins. Immunohistochemical assay was conducted to detect the expression of Cx43 and E-cadherin in PTs and MLNs, and the clinical and pathological implications were analyzed by statistical methods. In PTs, the expression of Cx43 and E-cadherin was significantly reduced, compared to adjacent normal tissues (P < 0.01). The expression of Cx43 and E-cadherin was significantly increased in MLNs compared with PTs (P < 0.01 and P < 0.01, for Cx43 and E-cadherin, respectively), and some Cx43 and E-cadherin-negative PTs developed Cx43 and E-cadherin-positive MLNs. Furthermore, reduced expression of both Cx43 and E-cadherin significantly correlated with poor differentiation, advanced TNM stage, and lymph note metastasis of gastric cancers. Cx43 and E-cadherin expression significantly correlated with each other. We concluded that concurrent reduction in Cx43 and E-cadherin may contribute to the occurrence of gastric cancer. However, concurrent increased expression of Cx43 and E-cadherin may contribute to the efficient metastasis of gastric cancer to the lymph nodes.

[Connexin 43 expression in intraperitoneal free gastric cancer cells in patients with gastric cancer].

OBJECTIVE: To examine the association of connexin 43 (Cx43) in the intraperitoneal free gastric cancer cells and clinicopathological characteristics. METHODS: Immunohistochemistry and immunofluorescence staining were used to detect connexin 43 in 75 paraffin-embedded gastric cancer tissues, matched paracancerous tissue, and intraperitoneal free gastric cancer cells. RESULTS: The positive rates of Cx43 expression were 33.3% (25/75) in gastric cancer tissue specimens and 100% (75/75) in matched paracancerous tissue (P<0.01). The positive detection rate of free cancer cells in peritoneal lavage was 38.6% (29/75) and the positive rate of Cx43 in peritoneal free gastric cancer cells was 72.4% (21/29), which was significantly higher than that in gastric cancer tissue specimens (P<0.01). Significant association was observed of Cx43 expression of free gastric cancer cells with tumor infiltration and histological type (P<0.05). CONCLUSION: Cx43 gene may be involved in the mechanism of peritoneal metastasis of gastric cancer.

Programmed cell death 4 (PDCD4) enhances the sensitivity of gastric cancer cells to TRAIL-induced apoptosis by inhibiting the PI3K/Akt signaling pathway.

OBJECTIVE: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is thought to be a promising anti-neoplastic agent because of its ability to selectively induce apoptosis in cancer cells. However, some cancer cells are resistant to TRAIL. The mechanisms underlying this resistance are unclear. The aim of this study was to explore the role of programmed cell death 4 (PDCD4) in regulating TRAIL sensitivity in gastric cancer cells. METHODS: PDCD4 complementary DNA and PDCD4-specific short-hairpin RNA (shRNA) fragments were transfected into TRAIL-sensitive and -resistant gastric cancer cells. Expression of PDCD4 and Akt was detected via western blot. Cell survival and apoptosis were measured using 3-(4,5-dimethylthiazolyl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry (FCM) assays. RESULTS: We found that upregulation of PDCD4 enhanced TRAIL sensitivity in gastric cancer cells. Downregulation of PDCD4 decreased TRAIL sensitivity. Inhibition of Akt by the phosphoinositide 3-kinase (PI3K) inhibitor LY294002 induced PDCD4 activity and enhanced TRAIL sensitivity in TRAIL-resistant gastric cancer cells. CONCLUSION: We demonstrated that PDCD4 regulates TRAIL sensitivity in gastric cancer cells by inhibiting the PI3K/Akt signaling pathway.

Systemic and peritoneal inflammatory response after laparoscopic-assisted gastrectomy and the effect of inflammatory cytokines on adhesion of gastric cancer cells to peritoneal mesothelial cells.

INTRODUCTION: There still remain concerns over the potential for peritoneal metastasis after laparoscopic surgery. We designed this trial to investigate the effects of the inflammatory cytokines interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α) on the interaction between gastric cancer cells and mesothelial cells, and to evaluate differences in both the peritoneal and systemic cytokine (IL-1ß and TNF-α) concentrations after laparoscopic and conventional surgical approaches, thus offering another possible advantage of laparoscopic procedures for treatment of gastric cancer. EXPERIMENTAL DESIGN: A reproducible human in vitro assay was developed to study adhesion of SGC-7901 and MKN-45 human gastric cancer cells to monolayers of primary cultured human peritoneal mesothelial cells (HPMCs). Tumor cell adhesion to a mesothelial monolayer was assessed after preincubation of the monolayer with IL-1ß and TNF-α using flow cytometry. Expression of adhesion molecules (ICAM-1, VCAM-1, and CD44) and their counterparts (LFA-1 and VLA-4) was investigated by real-time polymerase chain reaction (PCR) immunocytochemical staining. Furthermore, the proinflammatory cytokines IL-1ß and TNF-α were measured perioperatively in peritoneal drain fluid and in serum by enzyme immunoassay. RESULTS: Preincubation of the mesothelial monolayer with IL-1ß and TNF-α resulted in enhanced tumor cell adhesion of SGC-7901 and MKN-45 cells. Mesothelial cells showed significant enhancement of expression of ICAM-1, VCAM-1, and CD44 after stimulation with IL-1ß and TNF-α. Meanwhile their counterparts (LFA-1, VLA-4, and CD44) were identified in gastric cancer cells. The level of IL-1ß in peritoneal drain fluid and in serum perioperatively in the laparoscopy-assisted gastrectomy group was lower than in the conventional open gastrectomy group, whereas there were no significant differences between the laparoscopic-assisted distal gastrectomy (LADG) and conventional open distal gastrectomy(CODG) groups with respect to TNF-α. CONCLUSIONS: The presented results prove that IL-1ß and TNF-α are significant stimulating factors in gastric cancer cell adhesion in vitro and may therefore partly account for local tumor recurrence and peritoneal metastasis in vivo. Owing to less impact on the postoperative abdominal regional and systemic immune responses, laparoscopic surgery not only shows clinically relevant advantages but also causes less effect of inflammatory factors on local recurrence and peritoneal metastasis of gastric cancer than conventional operations. Thus, we offer another possible advantage of laparoscopic procedures for treatment of gastric cancer.

KAI1 gene suppresses invasion and metastasis of hepatocellular carcinoma MHCC97-H cells in vitro and in animal models.

BACKGROUND: Downregulation of KAI1 gene expression has been found in many types of cancer cells and is closely related to cancer invasion and metastasis. This study was aimed at investigating the effects and possible underlying mechanisms of KAI1 gene on invasion and metastasis of human hepatocellular carcinoma (HCC). METHODS: The invasive ability, visco-elastic properties and cell adhesion forces were analysed in different HCC cells originating from the MHCC97-H cell line transfected with either the sense or the antisense KAI1 expression plasmid. Tumuorigenicity, metastatic abilities, extracellular matrix (ECM) and intercellular adhesion molecule-1 (ICAM-1) expression were also evaluated in the nude mouse models of the xenografted and orthotopic liver cancer cells. RESULTS: Compared with their parental cells, in the HCC cells transfected with the sense KAI1 gene, the invasive ability in vitro was significantly decreased (P<0.01); the cellular elastic coefficients K(1), K(2) and mu were significantly higher (P<0.05); the cells adhesion forces to fibronectin were significantly lower (P<0.01). The sense KAI1 gene transfection into the cancer cells also inhibited their invasion and lung metastasis in the orthotopic liver cancer nude mice. However, the opposite changes were observed in the HCC cells transfected with the antisense KAI1 gene. KAI1 gene transfection also affected ECM and ICAM-1 expression in the transplanted liver cancer. CONCLUSION: The KAI1 gene plays an important role in the invasion and metastasis of human HCC and its upregulation in HCC cells suppresses their invasive and metastatic abilities. KAI1 gene functioned as a metastasis inhibitor by regulating the HCC cell biophysical behaviours including aggregation, adhesion, motility and visco-elastic properties.

[Transcription regulation of 5-Aza-2'-deoxycytidine on maspin gene demethylation in RKO human colorectal cell line].

OBJECTIVE: To detect the methylation status of 5'CpG island in the core promotor of maspin gene in RKO human colorectal cell line,and to explore the transcription regulation of DNA 5'CpG island demethylation on maspin tumor suppressor gene and its effect on the growth of cancer cell. METHODS: The status of 5 'CpG island methylation of maspin gene in RKO human colorectal cell line was analyzed using methylation specific polymerase chain reaction (MSP). After treated with a specific demethylating agent, 5-Aza-2'-deoxycytidine, reverse transcription polymerase chain reaction (RT- PCR) was used to examine maspin gene expression. Cell proliferation was evaluated using MTT assay,distribution of cell cycle and rate of apoptosis were determined using flow cytometry. RESULTS: The 5'CpG island methylation in the core promotor of maspin gene was detected in RKO human colorectal cell line. After treatment with three different concentration of 5-aza-2'-deoxycytidine, the expression of maspin mRNA increased 10.89, 16.91, 23.97 times respectively. MTT array showed the proliferation activity of RKO cell line was obviously reduced after 5-aza-2'-deoxycytidine treatment. The cells were arrested in G(0)/G(1) phase,and the apoptosis rates were 5.17%, 8.71% and 11.23% respectively compared with control group. CONCLUSION: The 5'CpG island methylation is probably responsible for maspin expression silencing in RKO human colorectal cell line, 5-aza-2'-deoxycytidine may effectively cause demethylation and inhibit the growth of tumor cell by reactivating the gene transcription silenced by aberrant hypermethylation.

[The synergistic inhibitory effect of 5-aza-2-deoxycytidine and Tamoxifen on estrogen receptor alpha negative breast cancer cell lines in vitro].

OBJECTIVE: To observe if ER alpha gene can be induced by 5-aza-CdR in ER alpha negative human breast cancer cell lines (MDA-MB-231 and MDA-MB-435) and the synergistic inhibitory effects of 5-aza-CdR and Tamoxifen on these two cell lines in vitro. METHODS: The status of 5'CpG island methylation of ER alpha gene in ER alpha negative (MDA-MB-231 and MDA-MB-435) human breast cancer cell lines and 20 cases of breast cancer tissue was studied by MSP, the expression of ER alpha mRNA was inspected by using RT-PCR after these two cell lines were treated with 5-aza-CdR. Cell proliferation was evaluated by MTT assay, distribution of cell cycle and rate of apoptosis were determined by flow cytometry after these two cell lines were treated with 5-aza-CdR or TAM alone, or in combination in vitro. RESULTS: The 5'CpG island is methylated in the core promotor of ER alpha gene in ER alpha negative (MDA-MB-231 and MDA-MB-435) human breast cancer cell lines and the methylating rate is 25.0%, 66.7%, 83.3%, 100% in 20 cases of breast cancer tissue of stage I, II, III, IV, respectively. The expression of ER alpha mRNA was induced in these two cell lines after treated with 5-aza-CdR, MTT array showed the proliferation activity of these two cell lines was obviously reduced in 5-aza-CdR group and the inhibitory effect on proliferation was enhanced when 5-aza-CdR combined with TAM compared with control group, the induction of apoptosis was 11.20% and 8.71% respectively by 5-aza-CdR, while the rate of apoptosis is 48.8% and 53.1% when these two cells were treated with 5-aza-CdR combined with TAM. CONCLUSIONS: 5-aza-CdR can re-express ER alpha by demethylating and sensitive ER alpha negative human breast cancer cell lines to TAM, 5-aza-CdR and TAM synergistically inhibit proliferation and induce apoptosis in ER alpha negative human breast cancer cell lines, thus offer a new way for the treatment of ER alpha negative breast cancer.

Effects of KAI1 gene on growth and invasion of human hepatocellular carcinoma MHCC97-H cells.

AIM: To study the effects of sense and antisense KAI1 genes on the growth and invasion of human hepatocellular carcinoma (HCC) cell line MHCC97-H. METHODS: KAI1 sense and antisense eukaryotic expression plasmids were constructed using subclone technique and transfected into MHCC97-H cells respectively by DOTAP liposome. After successful transfection was confirmed, in vitro growth curve, cell cycles, plate clone formation efficiency, invasive ability in Boyden Chamber assay and ultrastructural morphology were studied. RESULTS: KAI1 sense and antisense genes had no significant effects on the cell growth curve and cell cycles. After transfection with sense KAI1 gene, decreased invasive ability in Boyden Chamber assay and decreased amount of mitochondria, but no significant changes of plate clone formation efficiency were observed in MHCC97-H-S cells. The plate clone formation efficiency and invasive ability in Boyden Chamber assay were significantly increased in MHCC97-H-AS cells, after transfection with antisense KAI1 gene. Furthermore, increased amount of mitochondria, rough endoplasmic reticulum, Golgi apparatus and expanded endoplasmic reticulum were also noted in MHCC97-H-AS cells. CONCLUSION: Changes of KAI1 expression in HCC cells may alter their invasive and metastasis ability of the tumor.