Bacteriophage biopanning in human tumour biopsies to identify cancer-specific targeting ligands.

Intravenous targeting of anticancer agents should improve both efficacy and therapeutic index. However, rational design of targeting constructs requires detailed definition of receptor targets and must take account of polarised tissue architecture that may restrict access to chosen receptors from the bloodstream. Bacteriophage biopanning provides a solution to this problem, identifying targeting sequences by functional selection rather than design, although reiterative panning in polarized human tumours has not previously been attempted. Here, we report an ex vivo, intra-arterial method for biopanning in freshly-resected human tumours, enabling reiterative selection of oligopeptide sequences capable of intravascular targeting to human colorectal tumours. Significant consensus was observed after two rounds of panning in tumours from different patients, and lead sequences demonstrated tumour targeting in samples from unrelated patients. This novel approach may be applicable to a wide range of settings, thus enabling iteration of consensus targeting sequences for tumour imaging and selective delivery of anticancer agents.

In vivo bactericidal activities of Japanese rice-fluid against H. pylori in a Mongolian gerbil model.

PURPOSE: The antibiotic effect of rice-fluid on Helicobacter pylori infection was investigated using a Mongolian gerbil model. METHODS: Gerbils were divided into four groups: H. pylori -infected, rice-fluid-treated animals (group A); H. pylori -infected, untreated animals (group B); uninfected, rice-fluid-treated animals (group C); and uninfected, untreated animals (group D). Group A and B animals were killed 14 weeks after H. pylori infection and group C and D animals were killed at the same age. The stomachs were examined for histology, 5'-bromo-2'-deoxyuridine (BrdU) labeling, and the bacterial burden. Serum anti-H. pylori antibody titers were also tested. RESULTS: The positive incidence of H. pylori -culture was 25 and 84 % in groups A and B, respectively (p<0.01). Both the degree of inflammation and the BrdU labeling index in group A were significantly lower than those in group B. CONCLUSIONS: Rice-fluid showed an antibiotic effect on H. pylori and an anti-inflammatory effect on the H. pylori -associated gastritis.

A clinical study of docetaxel with or without 5'DFUR as a second-line chemotherapy for advanced gastric cancer.

We conducted a clinical pilot study to evaluate the efficacy and safety of the combination of docetaxel and 5'DFUR as a second-line chemotherapy for gastric cancer. Twenty-four patients were divided into two groups by simple randomization: group A (60 mg/m2 of docetaxel, every 3 wk) and group B (regimen A + 600 mg/body of 5'DFUR). The response rate was 17% and 42% in group A and B, respectively (p < 0.05). The MST from the start of the first-line was 17 mo in group B. The major adverse event was leukopenia in both groups.

Suppressive effect of rice extract on Helicobacter pylori infection in a Mongolian gerbil model.

BACKGROUND: Rice extract has been shown to protect gastric mucosa from stress-induced damage. In this study, the antibiotic effect and the anti-inflammatory effect of orally administered aqueous rice extract on Helicobacter pylori infection and H. pylori-induced gastritis, respectively, in Mongolian gerbils were investigated. METHODS: Fifty specific-pathogen-free male Mongolian gerbils, seven weeks old, were divided into four groups: uninfected, untreated animals (group A); uninfected, rice extract-treated animals (group B); H. pylori-infected, untreated animals (group C); and H. pylori-infected, rice extract-treated animals (group D). Group C and D animals were killed 12 weeks after H. pylori infection (i.e., at 19 weeks of age) and group A and B animals were also killed at age 19 weeks. The stomachs were removed for histopathological examination with hematoxylin-and-eosin staining and anti-5'-bromo-2'-deoxyuridine (BrdU) immunostaining, and to determine the bacterial burden. Serum anti-H. pylori antibody titers were also tested. RESULTS: In groups A and B, the gastric mucosa showed no inflammatory cell infiltration and a few BrdU-reactive cells. Group C animals developed marked chronic active gastritis in the gastric mucosa, and BrdU-labeled cells in the gastric mucosa markedly increased in number. In group D animals, a significant reduction occurred in the degree of neutrophilic polymorphonuclear cell infiltration into the gastric mucosa, in the BrdU-labeling indices of gastric epithelial cells, and in anti-H. pylori antibody titers in the serum (P < 0.01), compared with although H. pylori was not completely eradicated. CONCLUSIONS: The rice extract was effective in suppressing inflammation and epithelial cell proliferation in the gastric mucosa in H. pylori-infected Mongolian gerbils. The rice extract has potential to exhibit a protective effect on H. pylori-related gastric mucosal diseases.

Identification of FGF receptor-binding peptides for cancer gene therapy.

Linear FGF receptor-binding heptapeptides were identified by phage display using sequential rounds of biopanning against cells with displacement of phage by FGF2. The consensus motif MXXP was iterated after four to five rounds and the peptide MQLPLAT was studied in depth. Phage bearing MQLPLAT showed high levels of binding to FGF receptor positive cells, with over 90% of phage bound being eluted competitively by adding free FGF2. MQLPLAT phage showed only limited binding to Cos7 cells deficient in receptors for FGF. MQLPLAT phage bound to SKOV3 cells with a K(d) of 2.51 x 10(-10) M. Although binding could be blocked by preincubation with free FGF2, heparin could not displace the phage. Use of MQLPLAT to target polyelectrolyte gene delivery vectors in vitro in the presence of serum achieved up to 40-fold greater transgene transduction than nontargeted vectors. MQLPLAT phage were administered into gastric carcinomas via the tumor-feeding artery immediately following resection from patients. The phage showed up to 9-fold more accumulation in the tumor than in adjacent regions of normal tissue, whereas control phage showed less than 2-fold. These peptides should provide useful ligands for specific delivery of gene therapy vectors to clinically relevant targets.

Use of a phage display library to identify oligopeptides binding to the lumenal surface of polarized endothelium by ex vivo perfusion of human umbilical veins.

Human endothelial-specific targeting peptides were identified by biopanning within freshly-obtained human umbilical cords. Umbilical veins were cleaned in situ and M13 phage display libraries were passed through the cords. Tightly bound phage were recovered following isolation of endothelial cells by collagenase digestion and homogenisation, allowing production of enriched phage libraries for subsequent rounds of panning. After five rounds of biopanning, five promising sequences were selected and the binding of the corresponding phage clones was compared in perfused umbilical veins. Each of these peptides showed substantial binding, although the clone encoding the heptapeptide KPSGLTY showed the greatest, some 89-times greater than insertless phage. Binding of this phage clone was examined to cells in vitro, where it demonstrated at least five-times greater binding to isolated human umbilical vein endothelial cells than to 911, SKOV3, B16F10 and Cos7 cells. These initial peptides may prove useful targeting agents for endothelial-selective delivery, and this powerful approach should be readily applicable to biopanning in a broad range of human vessels ex vivo.

Distribution of thymidine phosphorylase activity in gastric carcinoma and adjacent normal gastric tissue.

BACKGROUND/AIMS: Thymidine phosphorylase was reported to be identical to the angiogenic factor, platelet-derived endothelial cell growth factor. In this study we investigated the distribution of thymidine phosphorylase activity in human gastric carcinoma or normal gastric tissue using the ELISA system. METHODOLOGY: A longitudinal slice in the center of the gastric carcinoma of resected specimens from 6 patients with gastric carcinoma was used, and thymidine phosphorylase activity was mapped in each case. RESULTS: In all cases, the thymidine phosphorylase activities were significantly higher in tumors than adjacent normal gastric tissues. The amount and distribution of thymidine phosphorylase activity were different between intestinal-type and diffuse-type carcinoma. The thymidine phosphorylase activities in the invasive front of tumor were significantly lower than those in the other part in intestinal-type carcinoma. CONCLUSIONS: The ELISA system used in this study proved useful for the determination of thymidine phosphorylase activities in tissue sections.

COP35, a cholangiocarcinoma-binding oligopeptide, interacts with the clathrin heavy chain accompanied by GRP78.

Cholangiocarcinoma (CCA) is a common carcinoma of the liver, and the majority of patients with CCA have a poor prognosis due to the lack of effective nonsurgical therapies in addition to its rapid progression and inoperability at the time of diagnosis. The development of novel nonsurgical therapeutics that efficiently target CCA could significantly improve the prognosis for patients presenting with CCA. Here, we describe the iterative production and characterization of a novel peptide, designated COP35 (CCA-binding oligopeptide 35), which binds selectively to human CCA, identified by bacteriophage biopanning using the intrahepatic CCA cell line RBE and the normal cholangiocyte cell line MMNK-1. COP35 was found to augment the growth inhibitory effects of 5-fluorouracil (5-FU) against RBE cells. Utilizing pull-down assay and liquid chromatography, we identify the clathrin heavy chain accompanied by GRP78/BiP as a COP35-binding partner. In summary, we identify COP35 as a possible candidate for peptide-targeted therapies for CCA.

Modified Irinotecan/5FU/Leucovorin therapy in advanced colorectal cancer and predicting therapeutic efficacy by expression of tumor-related enzymes.

OBJECTIVE: To evaluate the efficacy and safety of a regimen using Irinotecan, 5FU and Leucovorin for patients with advanced or recurrent colorectal cancer. MATERIAL AND METHODS: Irinotecan (75 mg/m(2)) was administered biweekly, while 5FU (600 mg/m(2)) and Leucovorin (250 mg/m(2)) were administered weekly, for 6 weeks. RESULTS: The 21 consecutive patients subjected to this regimen showed a good response rate (43%) with minimal toxicity (incidence of grade 3/4: leukopenia and neutropenia, 5%, respectively, and vomiting, 10%). The mean survival time of all 21 patients was 15.7 months. This regimen could be a valid option for patients with advanced colorectal cancer, especially those seeking a good QoL (quality of life) for the remainder of their lives. We evaluated the expression of thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), thymidine phosphorylase (TP) and orotate phosphoribosyl transferase (OPRT) mRNAs, and sialyl Lewis X on formalin-fixed, paraffin-embedded colorectal tumor samples. Expression of TS mRNA or sialyl Lewis X was negatively correlated with the response from chemotherapy. Patients with low DPD mRNA expression in the tumor showed a significant longer survival than those with high expression. In patients with high TP mRNA expression, there was a tendency towards a high incidence of leukopenia. CONCLUSIONS: Some predictive factors elucidated in this study could contribute to the progress of the tumor-biology based, individualized chemotherapy for colorectal cancer patients.

Effects of a novel histamine H2-receptor antagonist, lafutidine, on the mucus barrier of human gastric mucosa.

BACKGROUND AND AIM: Lafutidine is a novel histamine H(2)-receptor antagonist used primarily as an antisecretory agent in Japan. Previous human studies have not assessed its gastroprotective effects. The purpose of the present study was to determine the effects of lafutidine on the human gastric mucus layer using both histological and biochemical methods. METHODS: Of the 14 patients scheduled for gastrectomy who consented to participate, seven were given 14 days of lafutidine 20 mg/day (lafutidine group) and the others received no medication (control group). The surface mucus gel layer in Carnoy-fixed tissue sections was examined immunohistochemically. Both the thickness of the mucus layer and its mucin content were measured in gastric corpus mucosa. RESULTS: There was no detectable difference between the groups in the grade of gastritis or the immunohistochemical staining characteristics. The laminated structure of the surface mucus gel layer was retained after administration of lafutidine and it was thicker than the layer in the control group. The surface layer in the lafutidine group had three-fold more mucin than that in the control group. There was no difference between the two groups in the mucin content of the deep mucosa. CONCLUSION: Lafutidine, given at clinical dosages, not only inhibits acid secretion but also strengthens the mucus barrier of the human gastric mucosa.

Trefoil factor 2 in gland mucous cell mucin in the mucous gel covering normal or damaged gastric mucosa using the Mongolian gerbil model.

OBJECTIVE: Trefoil factor 2 (TFF2) is localized in gastric gland mucous cells. The purpose of the study was to determine whether TFF2 and gastric mucin are localized in mucous cells and in the surface mucous gel layer (SMGL) of the normal gastric mucosa or in the mucoid cap adherent to gastric mucosal lesions in Mongolian gerbils. MATERIAL AND METHODS: Gastric mucosal lesions were induced in Mongolian gerbils using oral administration of Helicobacter pylori (H. pylori), subcutaneous administration of indomethacin, or oral administration of 30% ethanol. Tissue samples were fixed in Carnoy's solution for preservation of the SMGL, dehydrated, and embedded in paraffin. Histochemical staining for gastric mucins and immunostaining for TFF2 were performed. RESULTS: It was found that surface mucous cell mucin and gland mucous cell mucin were segregated in the SMGL covering the normal gastric mucosa, and the mucin of the mucoid cap covering the mucosal lesions was primarily gland mucous cell mucin. There was a co-localization of TFF2 in gland mucous cell mucin in gland mucous cells, the SMGL, and the mucoid cap. CONCLUSIONS: The co-localization of TFF2 in gland mucous cells and in the adherent mucus suggests a physical interaction between TFF2 and gland mucous cell mucin, and the participation of TFF2 trapped in the adherent mucus functions in mucosal defense, healing, and repair.

Efficacy of S-1 for patients with peritoneal metastasis of gastric cancer.

BACKGROUND: This study was designed to examine the efficacy and compliance of S-1 for the patients with peritoneal metastasis of gastric cancer. METHODS: Sixteen consecutive patients with peritoneal metastasis of gastric cancer were treated with S-1. Their survival was compared with that of the historical control group (25 patients). Thymidylate synthase, dihydropyrimidine dehydrogenase, thymidine phosphorylase and orotate phosphoribosyl transferase mRNA expression in the tumor were evaluated. RESULTS: The median survival time of S-1-treated patients was 550 days, which was significantly longer than that of the historical control group (215 days). We elucidated some factors to prolong the survival of the patients treated with S-1 for peritoneal metastasis: peritoneal metastasis without other distant metastases, the combination of S-1 treatment and gastrectomy, and low expression of thymidine phosphorylase mRNA in primary tumors. CONCLUSIONS: S-1 showed a surprisingly long-term survival with minimum toxicity in patients with peritoneal metastasis of gastric cancer.

Identification of an oligopeptide binding to hepatocellular carcinoma.

OBJECTIVES: We carried out identification of a small peptide binding to human hepatocellular carcinoma (HCC) cells with the aim of applying the peptide for future HCC-targeted therapy or imaging. METHODS: The biopanning technique using phage peptide display libraries was performed on HCC cells in vitro, and a phage clone expressing the HCC-binding peptide motif was selected. The binding activity of the selected phage was evaluated by plaque infection assay and immunofluorescence on cell lines. In addition, the binding activity of the peptide-expressing phage was investigated using HCC specimens derived from patients who had undergone hepatectomy for HCC. RESULTS: A heptapetide, Thr-Thr-Pro-Arg-Asp-Ala-Tyr (TTPRDAY), was identified as a motif binding to HCC. TTPRDAY bound specifically to HCC cells in comparison with other cancer cells, and the binding to HCC cells was also confirmed by immunofluorescence. In addition, the synthesized TTPRDAY peptide showed binding activity and a non-mitogenic effect on HCC cells in vitro. TTPRDAY-presenting phage showed more significant binding to HCC cells derived from specimens obtained from actual patients than to non-cancerous liver tissue. CONCLUSION: The motif TTPRDAY, identified by the biopanning technique, shows significant binding to HCC cells.

Identification of oligopeptides binding to peritoneal tumors of gastric cancer.

This is a report of in vivo intraperitoneal biopanning, and we successfully identified a novel peptide to target the multiple peritoneal tumors of gastric cancer. A phage display library was injected directly into the abdominal cavity of mice bearing peritoneal tumors of human gastric cancer, and phages associated with the tumors were subsequently reclaimed from isolated samples. The tumor-associated phages were amplified and the biopanning cycle was repeated five times to enrich for high affinity tumor-selective binding peptides. Finally, a tri-peptide motif, KLP, which showed homology with laminin 5 (a ligand for alpha3beta1 integrin), was identified as a binding peptide for peritoneal tumors of gastric cancer. Phage clones displaying the sequence KLP showed 64-fold higher binding to peritoneal tumors than control phage and were preferentially distributed in tumors rather than in normal organs after intraperitoneal injection into mice. In addition, the KLP phages were more likely to bind to cancer cells in malignant ascites derived from a patient with recurrent gastric cancer. Synthesized peptide containing the motif KLP (SWKLPPS) also showed a strong binding activity to peritoneal tumors without cancer growth effect. Liposomes conjugated with SWKLPPS peptide appeared significantly more often in tumors than control liposomes after intraperitoneal injection into mice. Furthermore, modification of liposomes with SWKLPPS peptide enhanced the antitumor activity of adriamycin on gastric cancer cells. The peptide motif KLP seems a potential targeting ligand for the treatment of peritoneal metastasis of gastric cancer.

Natural history of gastric mucosal cytokine expression in Helicobacter pylori gastritis in Mongolian gerbils.

Data regarding the chronological changes in gastric mucosal cytokines in the different phases of Helicobacter pylori infection are unavailable. We examined Mongolian gerbils for up to 52 weeks after H. pylori (ATCC 43504) inoculation. Levels of mRNAs of mucosal cytokines (interleukin-1beta [IL-1beta], gamma interferon [IFN-gamma], IL-4, IL-6, and IL-10) were assessed using real-time reverse transcription-PCR. Starting 26 weeks after H. pylori inoculation, two clinicohistologic patterns appeared: gastric ulcers in 32% and hyperplastic polyps in 68% of gerbils. High levels of mucosal IL-1beta mRNA were observed early in the infection, reaching maximum at 4 weeks and then rapidly declining. Mucosal IFN-gamma mRNA also reached maximal levels at 4 weeks but remained high thereafter. Both IL-1beta and IFN-gamma mRNA levels were consistently higher in the pyloric mucosa than in the fundic mucosa. In contrast, IL-4, IL-6, and IL-10 mRNA levels peaked at 8 to 26 weeks and levels were similar in the pyloric mucosa and the fundic mucosa. IFN-gamma mRNA levels were significantly higher in gerbils with ulcers than in those with hyperplastic polyps (median IFN-gamma/glyceraldehyde-3-phosphate dehydrogenase ratio x 100,000 = 650 versus 338, respectively [antrum], and 172 versus 40, respectively [corpus]) (P < 0.05). We propose that the different outcomes (e.g., ulcers or hyperplastic polyps) might relate to imbalances among cytokines.