Ep-CAM is a significant prognostic factor in pancreatic cancer patients by suppressing cell activity

The identification of molecular markers useful for predicting prognosis in pancreatic cancer patients is crucial for advances in disease management. The epithelial cell adhesion molecule (Ep-CAM) is known to express in most epithelial malignancies and was reported as a tumor marker or a candidate of molecular targeting therapy. However, the clinical significance of Ep-CAM expression in pancreatic cancer is not well-known. We determined the difference of malignant potential between parental and Ep-CAM-transfected pancreatic cancer cell lines by using proliferation, invasion and migration assay. Furthermore, we determined the relationship between tumoral Ep-CAM expression of resected specimens and clinical prognosis in 95 pancreatic cancer patients receiving radical surgery at two different cancer centers. One of the three Ep-CAM-transfected cell lines showed significantly low proliferation rate compared with the parental cell, while there was no difference in the other two cell lines. In invasion and migration assays, Ep-CAM-transfected cells showed significantly lower malignant potential than parental in all of the three cell lines. In 95 pancreatic cancer patients, 47 patients showed high-Ep-CAM expression, while 48 patients showed low, and there was no difference of clinicopathological features between Ep-CAM high and low-expression group. High-Ep-CAM expression group showed significantly good prognosis in overall survival (3-year survival; 56.2 versus 19.2%, P=0.0018) as well as in disease-free survival (3-year survival; 40.3 versus 14.4%, P=0.038) compared with low-expression group. In addition, the impact of Ep-CAM was observed strongly in LN-negative group when the influence of Ep-CAM was examined with dividing patients into LN-positive and negative group. In multivariate analysis, Ep-CAM expression was one of the independent prognostic factors as well as histology and lymph node metastasis. Ep-CAM expression was found to be related to the suppression of pancreatic cancer cell activity and the good prognosis in pancreatic cancer patients receiving the curative resection.

Enhanced inhibitory effects of TBT chloride on the development of F1 rats

Neurotoxicity is one of the major effects of tributyltin (TBT). The effects on the next generation of F(1) rats exposed to TBT via the placenta and their dams' milk may be stronger than those on adults. Pregnant Wister rats were exposed to TBT at 0 and 125 ppm in their food. Half of the female F(1) rats in both groups were exposed to TBT at 125 ppm in their food from 9 to 15 weeks of age. Female F(1) rats were divided into the following groups: the control-control (CC) group, with no exposure; the TBT-control (TC) group, exposed to TBT via the placenta and their dams' milk; the control-TBT (CT) group, exposed to TBT via their food from 9 to 15 weeks of age; and the TBT-TBT (TT) group, exposed to TBT via the placenta, their dams' milk, and their food (n = 10/group). After administration, an open-field test and prepulse inhibition (PPI) test were performed at 15 weeks of age. The mean body weights of the TC and TT groups were significantly lower than that of the CC group from 9 to 15 weeks of age. The mean relative thymus weight of the TC and TT groups was significantly lower than that of the CC group. In the open-field test, a marked decrease in the total locomotion distance was observed in the TT group. The mean values in the TT and TC groups were significantly lower than that in the CC group. For the locomotion distance between 15 and 20 min, the mean values in the CT, TC, and TT groups were significantly lower than that in the CC group. The mean locomotor distance between 25 and 30 min in the TT group was significantly lower than that in the CC and TC groups. The mean values of instances of wall rearing in the TC, CT, and TT groups were significantly lower than that in the CC group. The mean value of face washing or body washing in the TT group was significantly lower than that in the CT group. There were no significant differences in indexes of the PPI test. Exposure to TBT via the placenta and their dams' milk inhibited the development of F(1) rats, which continued after weaning. Inhibition of the rats' activity induced by exposure to TBT via the placenta and their dams' milk and/or via their food was suggested. The effects were most evident in the TT group.

Disparity between serotonin- and acetylcholine-provoked coronary artery spasm

BACKGROUND AND HYPOTHESIS

Intrinsic vasoactive substances, such as serotonin and acetylcholine, are known to provoke coronary artery spasm in patients with vasospastic angina. It remains unclear, however, whether these different agents, which activate different receptors, produce spasms at the same sites in these patients. The present study was designed to clarify the disparity of receptor agonist-induced coronary artery spasms in the same patients.

METHODS

We conducted sequential provocative tests of coronary artery spasm by acetylcholine, serotonin, and ergonovine in 20 patients with rest angina examined with quantitative coronary angiography.

RESULTS

Coronary artery spasms were provoked in all patients at 27 spastic sites. In 13 patients, ergonovine provoked spasms and in 10 of 13 patients who were diagnosed with variant angina, both acetylcholine and serotonin provoked spasms at the same sites where ergonovine also did. In 4 of 13 patients, spasms were provoked by serotonin but not by acetylcholine. In the remaining seven patients, whose spasms were induced by ergonovine, spasms were produced by acetylcholine but not by serotonin. On coronary angiography, the spastic sites for both acetylcholine and serotonin, and those for serotonin alone, were located in the proximal segments of coronary arteries, whereas the spastic sites for acetylcholine alone were located in the distal segments.

CONCLUSIONS

This study documented the disparity between serotonin- and acetylcholine-induced spasms. Provocative tests using agents that activate different receptors may produce coronary artery spasms at the same and/or different sites, and this disparity may reflect the clinical heterogeneity of vasospastic ischemic syndrome.

Octaarginine-modified multifunctional envelope-type nanoparticles for gene delivery

This study describes a multifunctional envelope-type nano device (MEND) that mimics an envelope-type virus based on a novel packaging strategy. MEND particles contain a DNA core packaged into a lipid envelope modified with an octaarginine peptide. The peptide mediates internalization via macropinocytosis, which avoids lysosomal degradation. MEND-mediated transfection of a luciferase expression plasmid achieved comparable efficiency to adenovirus-mediated transfection, with lower associated cytotoxicity. Furthermore, topical application of MEND particles containing constitutively active bone morphogenetic protein (BMP) type IA receptor (caBmpr1a) gene had a significant impact on hair growth in vivo. These data demonstrate that MEND is a promising non-viral gene delivery system that may provide superior results to existing non-viral gene delivery technologies.

Development of a novel systemic gene delivery system for cancer therapy with a tumor-specific cleavable PEG-lipid

For successful cancer gene therapy via intravenous (i.v.) administration, it is essential to optimize the stability of carriers in the systemic circulation and the cellular association after the accumulation of the carrier in tumor tissue. However, a dilemma exists regarding the use of poly(ethylene glycol) (PEG), which is useful for conferring stability in the systemic circulation, but is undesirable for the cellular uptake and the following processes. We report the development of a PEG-peptide-lipid ternary conjugate (PEG-Peptide-DOPE conjugate (PPD)). In this strategy, the PEG is removed from the carriers via cleavage by a matrix metalloproteinase (MMP), which is specifically expressed in tumor tissues. An in vitro study revealed that the PPD-modified gene carrier (Multifunctional Envelope-type Nano Device: MEND) exhibited pDNA expression activity that was dependent on the MMP expression level in the host cells. In vivo studies further revealed that the PPD was potent in stabilizing MEND in the systemic circulation and facilitating tumor accumulation. Moreover, the i.v. administration of PPD or PEG/PPD dually-modified MEND resulted in the stimulation of pDNA expression in tumor tissue, as compared with a conventional PEG-modified MEND. Thus, MEND modified with PPD is a promising device, which has the potential to make in vivo cancer gene therapy achievable.

Phase II clinical study of combination therapy with irinotecan and S-1(IRIS) for inoperable recurrent advanced colorectal cancer: Hokkaido Gastrointestinal Cancer Study Group study HGCSG-0302)

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Background: We planned to conduct a phase II clinical study of combination therapy with irinotecan and S-1, a new oral anticancer drug of the fluorinated pyrimidine type. We reported the interium reports of this study in colorectal cancer patients at GI cancer Symposium 2006. Methods: The antitumor effect was the primary endpoint, while the safety, progression-free survival time, and median survival time were the secondary endpoints. The subjects were untreated patients with inoperable advanced colorectal cancer aged 20–75 years. Irinotecan was administered at a dose of 100 mg/m2 (on days 1 and 15) as an intravenous infusion over 90 minutes, and oral S-1 (40 mg/m2) was administered after breakfast and dinner and then withdrawn for 2 weeks. Results: Forty patients were enrolled in the present study. There were 23 men and 17 women. The median age was 62 years (range: 34 to 74 years). Two patient showed grade 4 neutropenia, but the next course could be given safely after dose reduction. Three patients had grade 3 diarrhea, but therapy could be continued with addition of an antidiarrheal drug. No other serious adverse reactions occurred (either hematological or non-hematological), and all patients could receive therapy safely on an outpatient basis. Interim analysis suggested excellent results, with a response rate of 50%. To date, 231 cycles (median 8, range 1–19) have been administered. Median relative dose intensity was 97% for S-1 and 87% for irinotecan. 36 pts are evaluable for efficacy: RR was 47.2% (95% CI, 30.9–63.5%) and Disease Control Rate (PR + SD) was seen in 94.4% of pts. PFS of this regimen is 320 days. MST is not reached. Conclusions: IRIS therapy achieved a high response rate and could be given safely. These findings suggest that the therapy has potential as first-line treatment for inoperable advanced recurrent colorectal cancer. It seems that IRIS is a good treatment equal to FOLFIRI. In addition, this regimen could qualify as a candidate for future combination therapy with a molecular-targeting drug. The latest data will be reported at the meeting.

No significant financial relationships to disclose.

Identification of an actin-binding site in p47phoxan organizer protein of NADPH oxidase

Actin has been reported to enhance the superoxide-generating activity of neutrophil NADPH oxidase in a cell-free system and to interact with p47phox, a regulatory subunit of the oxidase. In the present study, we searched for an actin-binding site in p47phox by far-western blotting and blot-binding assays using truncated forms of p47phox. The amino-acid sequence 319-337 was identified as an actin-binding site, and a synthetic peptide of this sequence bound to actin. The sequence shows no homology to other known actin-binding motifs. It is located in the autoinhibitory region of p47phox and includes Ser-328, a phosphorylation site essential for unmasking. Although a phosphorylation-mimetic p47phox mutant bound to actin with a lower affinity than the wild type, the same mutant interacted with filamentous actin more efficiently than the wild type. A mutant peptide p47phox (319-337, Ser328Glu) bound to filamentous actin more tightly than to monomer actin. These results suggest that p47phox moves to cortical actin when it becomes unmasked in the cells.

Atopic dermatitis-like symptoms in HR-1 hairless mice fed a diet low in magnesium and zinc

We aimed to develop an animal model for atopic dermatitis. HR-1 hairless mice fed a diet with reduced magnesium and zinc levels were compared with mice fed a standard diet. Skin dryness and wrinkle-like changes, scratching behaviour, decreased skin water content, increased transepidermal water loss and raised blood immunoglobulin E levels were seen in the group receiving the reduced magnesium and zinc diet compared with control mice. There were no significant differences in body weight or the weight of the major organs between the two groups. Haematological examination in both groups was normal apart from increased immunoglobulin E levels in mice fed a reduced magnesium and zinc diet. These mice may be useful models of atopic dermatitis; preparation of the animals is not particularly time consuming, the reproducibility is 100%, and atopic dermatitis symptoms occur even in a specific pathogen-free environment.

Quantitative Three-Dimensional Analysis of the Intracellular Trafficking of Plasmid DNA Transfected by a Nonviral Gene Delivery System Using Confocal Laser Scanning Microscopy

Since endosomal escape and the nuclear delivery of plasmid DNA (pDNA) constitute major barriers for transgene expression, a quantitative evaluation of intracellular trafficking of pDNA would be highly desirable in terms of optimizing a nonviral gene delivery system. In the present study, a novel strategy is proposed for the quantification of rhodamine-labeled pDNA in endosomes/lysosomes, cytosol, and nucleus. Endosomes/lysosomes and nucleus were stained with LysoSensor DND-189 and Hoechst 33258, respectively, to distinguish them from the cytosol. The pixel areas of the clusters derived from the rhodamine were used as an index for the amount of pDNA. This approach was applied to the analysis of the intracellular trafficking of pDNA transfected by LipofectAMINE PLUS, stearylated octaarginine (STR-R8), and octaarginine (R8). In the case of R8, most of the pDNA was trapped by endosomes/lysosomes. STR-R8 exhibited endosomal escape followed by nuclear translocation in a time-dependent manner. LipofectAMINE PLUS was the most effective in rapidly delivering pDNA to the nucleus as well as the cytosol. These differences in the intracellular trafficking of pDNA correlated well with the transgene expression. Therefore, this method enables the quantitative analysis of the intracellular pharmacokinetics of pDNA and promises to provide useful information for optimizing nonviral gene delivery systems.

Differential relationship between changes in tumour size and microcirculatory functions induced by therapy with an antivascular drug and with cytotoxic drugs. implications for the evaluation of therapeutic efficacy of AC7700 (AVE8062)

A novel combretastatin A-4 derivative, AC7700, which is now in Phase I clinical trials under a new code, AVE8062, has shown strong antitumour effects against solid tumours in rodents because of its powerful and continued stanching of the tumour blood flow (TBF). Despite the strong tumour-suppressing qualities of AC7700, it does not produce an immediate reduction in tumour size. To elucidate the reason for this effect, we investigated the relationship between the change in tumour size in Sato lung carcinoma (SLC) and circulatory functions after therapy with AC7700, doxorubicin (Adriamycin [ADR]), or mitomycin C (MMC). To measure time-lapse changes in TBF with the hydrogen clearance method at the same site after drug administration, we developed a new apparatus for keeping electrodes within a tumour. AC7700 led to the destruction of both cancer cells and tumour vessels by interrupting the supply of nutrients. Intravenous (i.v.) administration of fluorescent dyes after AC7700 treatment revealed no fluorescence within the tumour vessels, which confirmed that the tumour microcirculation had been completely blocked. In contrast, ADR led to the destruction of SLC tumour cells, but did not have the same effect on tumour vessels. Intravenously administered fluorescent dyes immediately reached the tumour, which indicated that the tumour vasculature remained intact, and the TBF remained at the preadministration level, even 6 days after ADR treatment. In addition, although the size of the tumour increased slightly for 2 days with ADR treatment, possibly because of swelling of the cancer cells, thereafter it continued to decrease. MMC had virtually no effect on SLC tumour cells, tumour size or tumour vessels. We conclude that changes in tumour size brought about by cancer chemotherapy depend not only on the sensitivity of the cancer cells to the drug in question, but also on the nature of changes in the microcirculatory functions of the tumour brought about by the therapy. When both tumour cells and the tumour vasculature are destroyed, the effectiveness of therapy can not be determined from changes in tumour size alone.

KAI1 expression can be a predictor of stage A prostate cancer progression

The disease progression and rate of cancer death were analyzed in 52 patients with stage A prostate cancer who underwent transurethral resection of the prostate (TURP) or retropubic subcapsular prostatectomy (SCP) between 1987 and 1998. We performed immunohistochemistry on 16 patients to determine the correlation between the expression of the tumor metastasis suppressor gene KAI1 and the subsequent progression of stage A prostate cancer. Nineteen and 33 of the patients had cancer at stage A1 and stage A2, respectively, and their subsequent courses were followed for an average of 53.7 months (24-134 months). Progression to clinical cancer was found in six patients (one with stage A1, and five with stage A2). This progression was evident 40.8 months (5-80 months) after TURP or SCP. Four (66.7%) of the patients died of cancer progression (average 31 months) after prostatectomy. All four patients had stage A2, poorly differentiated adenocarcinoma, and had been followed with administration of diethylstilbestrol diphosphate (DES-P). The disease-free patients (n=10) showed overexpression of KAI1 protein, compared to those with disease progression (n=6). These results indicate that progression arose mainly in the patients with stage A2 cancer, and that poorly differentiated, focal and weak expression of KAI1 protein is highly associated with disease progression. It is suggested that patients in this group should be treated with immediate total androgen blockade, radiation, or radical prostatectomy after diagnosis.Prostate Cancer and Prostatic Diseases (2001) 4, 150-153.

Identification of a short highly conserved amino acid sequence as the functional region required for posttranscriptional autoregulation of the cystathionine gamma-synthase gene in Arabidopsis

Cystathionine gamma-synthase (CGS) catalyzes the first committed step of Met biosynthesis in plants. We have previously shown that expression of the gene for CGS is feedback-regulated at the level of mRNA stability, and that the amino acid sequence encoded by the first exon of the CGS gene itself is responsible for the regulation (Chiba, Y., Ishikawa, M., Kijima, F., Tyson, R. H., Kim, J., Yamamoto, A., Nambara, E., Leustek, T., Wallsgrove, R. M., and Naito, S. (1999) Science 286, 1371-1374). To identify the functional region within CGS exon 1, deletion analysis was performed. The results showed that the 41-amino acid region of exon 1 highly conserved among plants is necessary and sufficient for the regulation. Analyses of in vivo and in vitro generated mutations that abolish the regulation identified the functionally important amino acids as 11-13 residues within this conserved region. The importance of these residues was confirmed by deletion analysis within the conserved region. These studies identified the functional region of CGS exon 1 required for the posttranscriptional autoregulation of the CGS gene as (A)RRNCSNIGVAQ(I), with uncertainty of the first and last residues. This sequence is almost perfectly conserved among CGS sequences of higher plants but cannot be found elsewhere in the public databases.