Intraoperative pathological investigation of recurrent nerve nodal metastasis can guide the decision whether to perform cervical lymph node dissection in thoracic esophageal cancer

Three-field lymph node dissection has been widely used to treat thoracic esophageal cancer, but is very invasive and can cause serious complications. Whether cervical lymph node dissection should be performed in all patients with thoracic esophageal cancer remains controversial. We pathologically examined the recurrent nerve lymph nodes during surgery in patients with thoracic esophageal cancer to determine the presence or absence of lymph node involvement. In patients without recurrent nerve nodal involvement, cervical lymph node dissection was not performed. Treatment outcomes were analyzed to evaluate whether intraoperative pathological investigation was a useful procedure. Among 71 patients with thoracic esophageal cancer who underwent 3-field lymph node dissection, the rate of cervical lymph node metastasis was 40.9% in patients with recurrent nerve nodal metastasis on intraoperative pathological investigation, as compared with 10.2% in patients without recurrent nerve nodal metastasis (p=0.007). Multiple logistic-regression analysis showed that recurrent nerve nodal metastasis was a strong predictor of cervical lymph node metastasis (odds ratio, 2.98; 95% confidence interval, 1.139-7.775; p=0.03). Among 41 patients who underwent intraoperative pathological investigation, 10 had recurrent nerve nodal metastasis and underwent cervical lymph node dissection. Two of these patients had histological evidence of cervical lymph node metastasis. The remaining 31 patients had no recurrent nerve nodal metastasis on intraoperative pathological examination and therefore did not receive cervical lymph node dissection. None of these patients had cervical lymph node recurrence on follow-up. We compared patients who underwent intraoperative pathological investigation with those who underwent conventional 3-field lymph node dissection (without performing intraoperative pathological investigation). The rates of cervical lymph node recurrence were similar among the groups (2.6% vs. 6.7%), but the 3-year survival rate was significantly higher in the patients who underwent intraoperative pathological dissection (83.3%) than in those who underwent 3-field dissection (57.2%; p<0.05). Although this was a retrospective study, our results suggest that outcomes of patients undergoing cervical lymph node dissection according to the results of intraoperative pathological investigation are at least as good as those in patients undergoing 3-field lymph node dissection. We conclude that intraoperative pathological investigation of recurrent nerve nodal metastasis is useful for determining whether cervical lymph node dissection should be performed in patients with thoracic esophageal cancer.

[An antitumor effect of oncolytic adenovirus capable of selectively replicating in CEA-expressing cancer cells and its enhancement by 5-FU]

In recent years, many have focused on the use of oncolytic virus capable of lysing cancer cells by a cancer-selective replication for a new treatment modality of cancer. In the present study, we used oncolytic adenovirus, AdCEAp/Rep, genetically modified to selectively replicate in CEA-expressing cancer cells, and investigated whether AdCEAp/Rep could induce selective cytotoxicity to CEA expressing cancer cells, and where the AdCEAp/Rep induced cytotoxic effect could be enhanced by 5 FU in using human gastric cancer cell lines, MKN45 (CEA-positive) and MKN74 (CEA-negative). The results showed that AdCEAp/Rep showed cytotoxicity against MKN45 in a dose-dependent manner, while it did not against MKN74. Furthermore, 5-FU remarkably enhanced AdCEAp/Rep-induced cytotoxicity against MKN45 by being added 3 days after adenovirus infection. These findings strongly suggest that AdCEAp/Rep may be applicable as a new therapeutic agent for clinical cancers expressing CEA in combination with chemotherapeutic agents such as 5-FU.

1173C>T polymorphism in VKORC1 modulates the required warfarin dose

The response to warfarin is highly variable among individuals and such variability is likely to have some genetic basis. We evaluted the effect of VKORC1 polymorphisms on warfarin response among Japanese, taking advantage of its unique population structure in which CYP2C9 *2 and *3 alleles are relatively rare. Thirty-one patients (12-34 years old; median, 22) on warfarin were recruited from a pediatric cardiology clinic. Genotyping of the C>T polymorphism at position 1173 in intron 1 of VKORC1 revealed that 26 patients (84%) were T/T homozygotes at nucleotide 1173, whereas 5 (16%) were C/T heterozygotes. Complete linkage disequilibrium was observed between the 1173C > T polymorphism and another polymorphism, the 3730G > A, in the 3' untranslated region. The C/T heterozyogtes at the 1173C > T polymorphism tended to require more warfarin than the T/T homozygotes, when adjusted for international normalized ratio (p = 0.003). Both the 1173C > T polymorphism and the 3730G > A polymorphism are likely to be inert from a functional standpoint. Rather, based on the complete linkage disequilibrium between 1173C > T and 3730G > A polymorphisms, we suspect that the actual change that defines the relative resistance to warfarin may be present in the proximity of these two polymorphisms.

[An early detection of recurrence using reverse transcriptase-polymerase chain reaction (RT-PCR) and methylation-specific polymerase chain reaction (MSP) from peripheral blood in patients after gastrectomy]

Several molecular approaches, using peripheral blood of patients with cancers, have been assessed recently for ability to detect various primary and recurrent cancers at an early stage. One is the reverse transcriptase polymerase chain reaction (RT-PCR) analysis, which can detect a small number of circulating cancer cells. Another is the methylation-specific polymerase chain reaction (MSP), which detects tumor-specific alterations of cell-free serum DNA released from tumor into the circulation by necrosis and/or apoptosis. In the present study, we set out to assess the diagnostic value of the RT-PCR assay and the MSP assay for an early detection of recurrent diseases in patients after curative gastrectomy. Two of the 25 patients (8%) exhibited a CEA specific signal in their peripheral blood. On the other hand, seven patients (28%) showed aberrant methylation of the promoter region of at least one gene (3 patients for p16, 3 for E-cadherin, 3 for RARbeta genes, and 1 for CDH4 respectively). No abnormal signal was detected in sera from volunteers who served as controls. Of 10 patients who developed recurrences, a CEA-specific signal and aberrant methylation was demonstrated in plasma samples of 1 and 4 patients, respectively. One patient, without definite findings of recurrence at the time of analysis, developed recurrences 6 months later. Both assays can serve as markers that allow selection of those cases requiring more intensive screening and aggressive postoperative treatment.

[Two cases of primary peritoneal cystadenocarcinoma--diagnosis, treatment, and clinical feature]

Primary peritoneal adenocarcinoma is rare, originating in the paramesonephric duct (müllerian duct). We report two cases of primary peritoneal adenocarcinoma. Both patients received a surgical resection. The pathological diagnosis of the resected specimen was papillary adenocarcinoma with clear cell carcinoma. The response after the combination chemotherapy using CDDP and TS-1 was "PR", and these treatments were effective to improve the patients' quality of life in each case.

[A case of immunotherapy using OK-432 in combination with RFA for CRT-resistant recurrent tumors of esophageal cancer that presented itself in the intramediastinal omentum of gastric tube]

The greater omentum contains abundant lymphoid tissues composed of a lot of macrophages and lymphocytes, and plays an important role in a host defense system in the peritoneal cavity. Also, it is well known to be an initial site of peritoneal disseminated metastases. We experienced a rare case of a 60-year-old man with postoperative recurrence of esophageal cancer that presented itself in the greater omentum of the gastric tube reconstructed through a mediastinal route, as well as through mediastinal lymph-nodes. We performed CT-guided radiofrequency ablation (RFA) for recurrent omental tumor that was refractory to chemoradiation therapy and growing rapidly adjacent to the trachea. In combination with local control using RFA, we attempted a systemic immunotherapy using OK-432, by subcutaneous injection around RFA to accelerate host antitumor immune responses induced by antigen stimulation by RFA, based on the immunological property of the omentum. RFA induced a significant therapeutic effect on the omental tumor with massive necrotic change. However, no apparent size reduction was seen in the metastatic mediastinal lymph nodes, although an increase of peripheral blood lymphocytes was observed before and after RFA, and systemic host immune responses were stimulated by OK-432.

The Range of Tumor Extension Should Have Precedence over the Location of the Deepest Tumor Center in Determining the Regional Lymph Node Grouping for Widely Extending Esophageal Carcinomas

BACKGROUND

The Japanese Guide Lines for the Clinical and Pathologic Studies on Carcinoma of the Esophagus (9th edn) give precedence to the location of the deepest tumor center rather than the range of tumor extension when determining regional lymph node grouping. We evaluated the validity of this recommendation.

METHODS

The subjects were 49 patients with carcinomas of the distal thoracic esophagus and cardia who had undergone esophagectomy with three-field lymph node dissection. We measured variables defining tumor location, such as the distance from the esophagogastric junction (EGJ) to the proximal margin of the tumor (DJP), the distance from the EGJ to the distal margin of the tumor (DJD), and the distance from the EGJ to the deepest tumor center (DJC). To examine the relation of tumor location to lymph node metastasis in the proximal direction, the patients were divided into two groups according to the presence (14 patients) or absence (35 patients) of middle-upper mediastinal and/or cervical lymph node metastases. These two groups were compared with respect to the above variables. To analyze lymph node metastasis in the distal direction, the patients were also divided into two groups according to the presence (12 patients) or absence (37 patients) of distant abdominal lymph node metastases. These two groups were similarly compared with respect to the above variables.

RESULTS

DJP was significantly longer in the patients with middle-upper mediastinal and/or cervical lymph node metastases than in those without such metastases. Multiple logistic regression analysis showed that the DJP was a better predictor of middle-upper mediastinal and/or cervical lymph node metastases than was the DJC. The DJD was significantly longer in the patients with distant abdominal lymph node metastases. Multiple logistic regression analysis also showed that the DJD was a better predictor of distant abdominal lymph node metastases than was the DJC.

CONCLUSIONS

The range of tumor extension is a more reliable predictor of the risk of distant lymph node metastases than is the location of the deepest tumor center in esophageal carcinoma.

Down-regulation of RUNX1, RUNX3 and CBFbeta in hepatocellular carcinomas in an early stage of hepatocarcinogenesis

BACKGROUND

Our previous studies suggested that deficient function of RUNX3 protein is causally related to development and progression of human gastric cancer. RUNX3 is mapped to 1p36, which is frequently deleted in hepatocellular carcinomas (HCC), therefore, these tumors were investigated for expression and copy number changes of RUNX3 and other Runt-related genes, RUNX1, RUNX2, and their co-factor CBFP. Similarly nearby uninvolved liver showing cirrhosis or normal histology was investigated in conjunction with various clinicopathological factors.

MATERIALS AND METHODS

Copy number change and expression change of RUNX family genes in 35 hepatocellular carcinoma specimens and adjoining liver with cirrhosis (LC) or normal histology were estimated using quantitative reverse transcription polymerase chain reaction (RT-PCR) and in situ hybridization.

Induction of cytotoxic T lymphocytes against human cancer cell lines using dendritic cell-tumor cell hybrids generated by a newly developed electrofusion technique

Recently, dendritic cells (DCs) and DC-tumor cell hybrids (DC-tumor hybrids) have been used for cancer vaccine therapy in a clinical trial. DC-tumor hybrids combine the potent antigen-presenting capacity of DCs with the ability to present all tumor antigens expressed on tumor cells to T cells. We used DC-tumor hybrids as stimulator cells to induce tumor-specific cytotoxic T lymphocytes (CTLs) in vitro. DC-tumor hybrids were generated from human monocyte-derived DCs and human cancer-cell lines (GT3TKB, lung cancer; GCIY, gastric cancer) by our newly developed electrofusion technique, established and refined with the use of mouse cells. To evaluate the capacity of DC-tumor hybrids generated by our method to induce tumor antigen-specific CTLs, we performed a cytotoxic assay and an interferon-gamma release assay using CD8-dominant effector lymphocytes induced by them. DC-tumor hybrids more effectively induced tumor-specific primary T-cell response than did stimulation with DCs co-cultured with irradiated tumor cells overnight, irradiated tumor cells alone, or a mixture of DCs and irradiated tumor cells. DC-tumor hybrids were generated at a high fusion rate by our electrofusion technique. When CTLs were induced by DC-tumor hybrids in vitro, the high fusion rate did not contribute to the induction of CTLs with increased tumor-specific cytotoxicity. The addition of interleukin-12 to the culture medium did not augment the cytotoxicity of CTLs. Overall, our results suggest that DC-tumor hybrids effectively induce human tumor-specific CTLs and may thus be applicable for clinical trials of adoptive immunotherapy.

Tracking of green fluorescent protein (GFP)-labeled LAK cells in mice carrying B16 melanoma metastases

In adoptive immunotherapy, in vivo trafficking of adoptively transferred cells, including their accumulation at tumor sites, remains to be further investigated. Tracking of these cells by visualization is useful to clarify antitumor mechanisms and develop new modalities to enhance antitumor capacities. In the present study, an in vivo tracking study was performed using an adoptive transfer model of lymphokine-activated killer (LAK) cells induced from green mice into C57/BL6 mice with B16 melanoma metastases. Green mice are green fluorescent protein (GFP) transgenic mice originating from C57/BL6 mice. All of the tissues, except for erythrocytes and hair, express green fluorescence under excitation light. Although LAK cells in combination with IL-2 potently suppressed pulmonary metastases with survival prolongation, very few LAK cells accumulated in tumor tissues compared to those localized in the spleen, as visualized by fluorescent microscopy and quantitated by flow cytometry. The present method using transfer of green mice-derived cells into parental tumor-bearing mice is simple because there is no need for in vitro labeling and is feasible for the in vivo tracking of effector cells in an adoptive immunotherapy model.

Monoclonal antibody conjugated to gadolinium as a contrast agent for magnetic resonance imaging of human rectal carcinoma

BACKGROUND AND OBJECTIVES

Local disease is the most frequent recurrence pattern of rectal carcinoma, and its prognosis is not good. One reason for the poor prognosis is the difficulty of making the diagnosis at an early stage. To detect local recurrence as early as possible, we produced the monoclonal antibody, A7-gadolinium (Mab A7-Gd), conjugate as a contrast agent for magnetic resonance imaging to distinguish between carcinoma and normal tissue.

METHODS

We examined the in vitro immunoreactivity of Mab A7 coupled to Gd by chelate, and stability of Mab A7-EDTA-Gd in human serum. Its in vivo distribution in nude mice with human colorectal carcinoma was also examined.

RESULTS

Mab A7-Gd retained binding activities that were nearly identical to intact Mab A7. Mab A7-Gd was stable in human serum. More radiolabeled Mab A7-Gd accumulated in the tumor than normal mouse IgG-Gd. Both Mab A7-Gd and normal mouse IgG-Gd disappeared from blood linearly over time. Accumulation levels in normal tissues decreased linearly over time but were lower than those in tumors.

CONCLUSIONS

Mab A7 conjugated to gadolinium selectively accumulated in the tumor. Our results suggest that it is potentially suitable as a contrast agent for MR imaging to detect local rectal carcinoma recurrence.

A new strategy using autologous dendritic cells and lymphokine-activated killer cells for cancer immunotherapy: efficient maturation of DCs by co-culture with LAK cells in vitro

Among a variety of antigen presenting cells (APCs), accumulating results support that the mature dendritic cell (DC) has the potential to induce efficient cytotoxic T lymphocyte (CTL) responses in the context of peptide-based immunotherapy. DCs have been known to assume the mature form by signaling through the CD40-CD40 ligand (CD40L) interaction, which may be provided by activated CD4+ T cells expressing abundant CD40L molecules on their surfaces. Here, we report that DCs generated from peripheral blood monocytes obtained from patients with advanced cancer exhibit a mature phenotype after co-culturing with autologous lymphokine-activated killer (LAK) cells generated by the stimulation of peripheral blood mononuclear cells with anti-CD3 monoclonal antibody (mAb) and interleukin (IL)-2. Part of this process appeared to be dependent on the expression of CD40L on the surface of LAK cells, although it was also suggested that some other humoral factors produced by LAK cells may be involved in this effect as well. DCs derived from the donors, of which LAK cells demonstrated a higher Th1/Th2 ratio upon activation determined by the intracellular detection of interferon-gamma and IL-4, showed more efficient maturation upon co-culture with LAK cells than DCs from donors with a low Th1/Th2 ratio. Importantly, these matured DCs induced a two-times stronger antigen-presenting capacity measured by an allo-reactive mixed lymphocytes reaction assay as compared to immature DCs. These results imply the use of the combination of DCs and LAK cells for immunotherapy against cancer.

A randomized phase III trial of postoperative adjuvant therapy with S-1 alone versus S-1 plus PSK for stage II/IIIA gastric cancer: Hokuriku-Kinki Immunochemo-Therapy Study Group-Gastric Cancer (HKIT-GC)

In this randomized multicenter Phase III study, patients with curatively resected Stage II/IIIA gastric cancer were assigned to postoperative adjuvant therapy with an oral fluoropyrimidine S-1 alone (2 weeks of treatment and 1 week of rest for 6 months, followed by 2 weeks of treatment and 2 weeks of rest for 6 months) or S-1 combined with an oral biological response modifier PSK (the same regimen of S-1 plus daily PSK for 12 months). The main objective was to evaluate the survival benefit and quality of life (QOL) of combined therapy. The primary end points were the time to relapse and the duration of survival after surgery, i.e. the rates of disease-free survival and overall survival at 3 and 5 years. The secondary end points were the relations of survival rates to drug compliance, QOL, adverse events, postoperative complications, relapse status, and the preoperative expression of immune or tumor markers. The sample size was 140 per treatment arm.

Phase II study of a combination of S-1 and weekly paclitaxel in patient with advanced or recurrent gastric cancer

14033

Background: Based on the results of our phase I study on a combination of S-1 (tegafur, oxonic acid, and CDHP) and weekly paclitaxel (PTX) for advanced or recurrent gastric cancer (ARGC) (Ueda et al, ASCO 2004), we conducted a multi-center phase II study to prospectively evaluate efficacy, QOL, and toxicity of S-1 plus weekly PTX in patients with ARGC. Methods: Eligibility included patients with histologically-proven ARGC, 20–80 years old, having a ECOG performance status (PS) of 0–2 and adequate organ functions, and having received no prior chemotherapy except postoperative adjuvant therapies without taxanes. S-1 was given orally at a dose of 80 mg/m2/day for 14 consecutive days (days 1–14) followed by a 2-week rest. PTX was administered weekly as a 1-hour intravenous infusion on days 1, 8, and 15. This treatment was repeated every 4-weeks as one cycle. Results: Fifty-four patients with measurable lesions (RECIST) were enrolled between Feb. 2004 and Nov. 2005. Histologically, a half of the patients had differentiated type and the other patients had undifferentiated type adenocarcinoma. The median age was 61 (range, 38–78). Three-fourths were male patients. The PS was 0/1/2 in 47/6/1 patients respectively. Thirty nine were primary cases and 15 were recurrent cases after gastrectomy. Treatment was terminated in two patients for toxicities and in one patient for refusal during the first cycle; thus compliance of 94.4%. A total of 254 cycles were administered (median 4.7, range 2–14), and 45 patients were assessable efficacy and toxicity until Dec. 2005. In these 45 assessable patients, 2 CRs and 27 PRs were obtained, resulting in an overall response rate of 64.4%. Twelve pts (26.7%) had stable disease, and 4 pts (8.9%) progressed. The tumor control rate was 91.1%. Conclusions: The combination of S-1 and weekly PTX is highly active for ARGC, and can be given safely with good tolerance and convenience profile. It is a candidate for the standard regimen and expected to contribute to better prognosis and QOL in ARGC patients.

No significant financial relationships to disclose.

Mature dendritic cells generated from patient-derived peripheral blood monocytes in one-step culture using streptococcal preparation OK-432 exert an enhanced antigen-presenting capacity

Dendritic cells (DCs) have been shown to be potent in inducing cytotoxic T cell (CTL) response leading to the efficient anti-tumor effect in active immunotherapy. Myeloid DCs are conventionally generated from human peripheral blood monocytes in the presence of interleukin (IL)-4 and granulocyte/macrophage colony-stimulating factor (GM-CSF). Streptococcal preparation OK-432, which is known to be a multiple cytokine inducer, has been extensively studied as to its maturation effects on immature DCs using an in vitro culture system. The purpose of this study was to examine whether it could be possible to generate mature DCs directly from peripheral monocytes using OK-432. We specifically focused on the possibility that recombinant cytokines, which are considered to be essential for in vitro DC generation, could be substituted by OK-432. Human peripheral monocytes, which were obtained from patients with advanced cancer, were cultured with IL-4 and OK-432 for 7 days. Cultured cells were compared with DCs generated in the presence of IL-4 and GM-CSF with or without OK-432 with regard to the surface phenotype as well as the antigen-presenting capacity. As a result, the culture of monocytes in the presence of IL-4 followed by the addition of OK-432 on day 4 (IL-4/OK-DC) induced cells with a fully mature DC phenotype. Functional assays also demonstrated that IL-4/OK-DCs had a strong antigen-presenting capacity determined by their enhanced antigen-specific CTL response and exerted a Th1-type T cell response which is critical for the induction of anti-tumor response. In conclusion, human peripheral blood monocytes cultured in the presence of IL-4 and OK-432 without exogenous GM-CSF demonstrated a fully mature DC phenotype and strong antigen-presenting capacity. This one-step culture protocol allows us to generate fully mature DCs directly from monocytes in 7 days and thus, this protocol can be applicable for DC-based anti-tumor immunotherapy.

Monoclonal antibody A7 coupled to magnetic particles as a contrast enhancing agent for magnetic resonance imaging of human colorectal carcinoma

BACKGROUND

Local recurrence, the most frequent pattern of recurrence of rectal carcinoma, is almost always fatal. The difficulty of diagnosing local recurrence contributes importantly to the poor prognosis.

METHODS

We coupled monoclonal antibody (Mab) A7, which reacts specifically with human colorectal carcinoma, to ferromagnetic lignosite (FML) particles to distinguish rectal carcinoma from other tissues by magnetic resonance (MR) imaging. We examined retention of immunoreactivity by the A7-FML complexes in vitro, and also their distribution in vivo according to radiolabeling and MR imaging when injected into nude mice bearing human colorectal carcinoma xenografts.

RESULTS

A7-FML retained binding activity nearly identical to that of Mab A7. Significantly more (125)I-labeled A7-FML accumulated in engrafted tumors than did (125)I-labeled normal mouse IgG-FML complexes (P < 0.05). A7-FML disappeared rapidly from the blood. Normal tissues accumulated less (125)I-labeled A7-FML than tumors; this accumulation decreased linearly with time. In MR imaging, signal intensity was reduced in the tumor by the injection of A7-FML.

CONCLUSIONS

A7-FML is potentially useful as a MR contrast enhancing agent for human colorectal carcinoma xenografts implanted subcutaneously.

Long-term survival of a case with multiple liver metastases from duodenal gastrointestinal stromal tumor drastically reduced by the treatment with imatinib and hepatectomy

Constitutive activation of KIT receptor tyrosine kinase is a critical factor in the pathogenesis of gastrointestinal stromal tumors (GISTs). But there is little information on whether combination of imatinib mesylate (IM) and surgical treatment can prolong survival in the cases with unresectable multiple liver metastases. We report a case of postoperative recurrence of GIST treated by the tyrosine kinase inhibitor IM and surgical treatment. The initial complete response (CR) to treatment continued for 18 mo, but single liver metastasis showed regrowth in the left hepatic lobe during IM treatment. After partial resection of the recurrent tumor, postoperative course was uneventful and the patient has survived without recurrence for 24 mo. Currently, imatinib is the first-line therapy for non-resectable GISTs, but a single agent therapy often leads to tumor resistance. Even if tolerance to imatinib occurs, a combination of imatinib and surgical treatment can prolong survival in some cases as reported here. However, further studies on a large number of cases of recurrent GIST are necessary to evaluate the effectiveness of IM treatment combined with surgery.

Tissue engineering of small intestinal tissue using collagen sponge scaffolds seeded with smooth muscle cells

In a previously reported attempt to regenerate small intestine with autologous tissues, collagen scaffolds were used without cell seeding or with autologous mesenchymal stem cell seeding. However the regenerated intestine lacked a smooth muscle layer. To accomplish regeneration of a smooth muscle layer, this present study used collagen scaffolds seeded with the smooth muscle cells (SMC) in a canine model. Autologous SMC were isolated from stomach wall and cultured. Two types of scaffolds were fabricated: in SMC (+), cultured SMCs were mixed with collagen solution and poured into a collagen sponge; and in SMC (-), SMCs were omitted. Both scaffolds were implanted into defects of isolated ileum as a patch graft. Animals were euthanized at 4, 8, and 12 weeks; for the last time point, the ileal loop had been reanastomosed at 8 weeks. At 12 weeks, the SMC (-) group showed a luminal surface covered by a regenerated epithelial cell layer with very short villi; however only a thin smooth muscle layer was observed, representing the muscularis mucosae. In the SMC (+) group, the luminal surface was covered completely by a relatively well-developed epithelial layer with numerous villi. Implanted SMCs were seen in the lamina propria and formed a smooth muscle layer. Thus, we concluded that collagen sponge scaffolds seeded with autologous SMCs have a potential for small intestine regeneration.

Correlation between serum DNA methylation and prognosis in gastric cancer patients

BACKGROUND

Gastric carcinogenesis is thought to involve multiple genetic and epigenetic changes. The relationships between the promoter methylation status of relevant genes in the serum and outcomes in patients undergoing curative gastrectomy for cancer were investigated.

MATERIALS AND METHODS

Pre-operative serum samples obtained from 97 gastric cancer patients, who underwent radical gastrectomy, were subjected to methylation-specific polymerase chain reaction (MSP) assays for the p16, E-cadherin and retinoic acid receptor beta (RARbeta) genes.

RESULTS

Promoter hypermethylation of p16, E-cadherin and the RARbeta gene was detected in sera from 18 (19%), 24 (25%) and 24 patients (25%), respectively. Altogether, 47 patients (48%) showed hypermethylation of at least one gene analyzed. Survival curves differed significantly between groups defined by the methylation status of E-cadherin (p<0.05), but not those defined by p16 or RARbeta (p =0. 77 and 0. 19, respectively).

CONCLUSION

Serum MSP assays can provide not only diagnostic, but also prognostic information in gastric cancer.

Successful gene transfer into dendritic cells with cationized gelatin and plasmid DNA complexes via a phagocytosis-dependent mechanism

The use of gene-modified dendritic cells (DC) is a powerful tool to enhance antitumor immune responses stimulated by these cells in cancer immunotherapy. Cationized gelatin is preferably incorporated via phagocytosis and is gradually degraded by proteolysis while buffering lysosomal activity. This may be appropriate for gene transfer into phagocytic cells, such as immature DC. In the present study, successful transfection into monocyte-derived immature DC was demonstrated using cationized gelatin and plasmid DNA complexes. A high transfection efficiency, approaching 16%, was obtained upon transfection of the enhanced green fluorescent protein (EGFP) gene as evaluated by flow cytometry. Transgene expression of EGFP and murine interleukin 12 were also detected by RT-PCR. The antigen-presenting capacity of the transfected DC was equal to that of untransfected DC as evaluated by the allogeneic mixed lymphocyte reaction. Cationized gelatin has the potential to be a unique non-viral vector for gene transfer into DC.