Enhanced Expression of Fibroblast Growth Factor Receptor 3 IIIc Promotes Human Esophageal Carcinoma Cell Proliferation.

Deregulated expression of fibroblast growth factor receptors (FGFRs) and their ligands plays critical roles in tumorigenesis. The gene expression of an alternatively spliced isoforms of FGFR3, FGFR3IIIc, was analyzed by RT-PCR in samples from patients with esophageal carcinoma (EC), including esophageal squamous cell carcinoma (ESCC) and adenocarcinoma (EAC). The incidence of FGFR3IIIc was higher in EC [12/16 (75%); p=0.073] than in non-cancerous mucosa (NCM) [6/16 (38%)]. Indeed, an immunohistochemical analysis of early-stage ESCC showed that carcinoma cells expressing FGFR3IIIc stained positively with SCC-112, a tumor marker, and Ki67, a cell proliferation marker, suggesting that the expression of FGFR3IIIc promotes cell proliferation. We used EC-GI-10 cells endogenously expressing FGFR3IIIc as a model of ESCC to provide mechanistic insight into the role of FGFR3IIIc in ESCC. The knockdown of endogenous FGFR3 using siRNA treatment significantly abrogated cell proliferation and the overexpression of FGFR3IIIc in cells with enhanced cell proliferation. EC-GI-10 cells and ESCC from patients with EC showed endogenous expression of FGF2, a specific ligand for FGFR3IIIc, suggesting that the upregulated expression of FGFR3IIIc may create autocrine FGF signaling in ESCC. Taken together, FGFR3IIIc may have the potential to be an early-stage tumor marker and a molecular target for ESCC therapy.

Effects of rikkunshito, a kampo medicine, on quality of life after proximal gastrectomy.

BACKGROUND: The loss of the gastroesophageal junction after proximal gastrectomy (PG) induces various gastrointestinal symptoms, such as regurgitation, anorexia, and body weight loss, leading to impairment of the postoperative quality of life. In the present study, we investigated the long-term quality of life and the effects of rikkunshito, a traditional Japanese medicine (kampo), on the gastrointestinal symptoms and plasma ghrelin levels in patients with gastric cancer who had undergone PG. METHODS: Nineteen patients who had undergone PG> 6 mo before entry into the present study were enrolled. The plasma ghrelin levels, body weight, appetite, and Gastrointestinal Symptom Rating Scale (GSRS) scores were examined before and after the 4-wk administration of rikkunshito. A subgroup analysis was performed of patients showing a GSRS score of ≥ 2 before treatment, indicating the presence of gastrointestinal symptoms. RESULTS: The patients' body weight increased significantly after the administration of rikkunshito. Neither their appetite nor plasma acylated and deacylated ghrelin levels were significantly affected. In the subgroup analysis, the mean total GSRS score improved significantly from 2.6 ± 0.6 before the administration of rikkunshito to 1.9 ± 0.7 after administration because of the significant improvement in the subscale scores for abdominal pain, acid reflux, diarrhea, and constipation. CONCLUSIONS: The long-term quality of life was well preserved in the patients who had undergone PG at our hospital. In the patients with a baseline GSRS score of ≥2, rikkunshito significantly improved the symptoms of postgastrectomy syndrome, and its effect was possibly independent of the plasma ghrelin levels.

Hypoxia activates the cyclooxygenase-2-prostaglandin E synthase axis.

Hypoxia-inducible factors (HIFs), in particular HIF-1alpha, have been implicated in tumor biology. However, HIF target genes in the esophageal tumor microenvironment remain elusive. Gene expression profiling was performed upon hypoxia-exposed non-transformed immortalized human esophageal epithelial cells, EPC2-hTERT, and comparing with a gene signature of esophageal squamous cell carcinoma (ESCC). In addition to known HIF-1alpha target genes such as carbonic anhydrase 9, insulin-like growth factor binding protein-3 (IGFBP3) and cyclooxygenase (COX)-2, prostaglandin E synthase (PTGES) was identified as a novel target gene among the commonly upregulated genes in ESCC as well as the cells exposed to hypoxia. The PTGES induction was augmented upon stabilization of HIF-1alpha by hypoxia or cobalt chloride under normoxic conditions and suppressed by dominant-negative HIF-1alpha. Whereas PTGES messenger RNA (mRNA) was negatively regulated by normoxia, PTGES protein remained stable upon reoxygenation. Prostaglandin E(2) (PGE(2)) biosynthesis was documented in transformed human esophageal cells by ectopic expression of PTGES as well as RNA interference directed against PTGES. Moreover, hypoxia stimulated PGE(2) production in a HIF-1alpha-dependent manner. In ESCC, PTGES was overexpressed frequently at the mRNA and protein levels. Finally, COX-2 and PTGES were colocalized in primary tumors along with HIF-1alpha and IGFBP3. Activation of the COX-2-PTGES axis in primary tumors was further corroborated by concomitant upregulation of interleukin-1beta and downregulation of hydroxylprostaglandin dehydrogenase. Thus, PTGES is a novel HIF-1alpha target gene, involved in prostaglandin E biosynthesis in the esophageal tumor hypoxic microenvironment, and this has implications in diverse tumors types, especially of squamous origin.

Antibody responses against NY-ESO-1 and HER2 antigens in patients vaccinated with combinations of cholesteryl pullulan (CHP)-NY-ESO-1 and CHP-HER2 with OK-432.

Combination vaccines of the NY-ESO-1 protein complexed with cholesteryl pullulan (CHP), CHP-NY-ESO-1, and the truncated 146HER2 protein with CHP, CHP-HER2, were subcutaneously administered with the immuno-adjuvant OK-432 to eight esophageal cancer patients. Vaccination was well-tolerated. NY-ESO-1- and HER2-specific antibody responses were analyzed using the patients' sera and samples from previous single CHP-NY-ESO-1 or CHP-HER2 vaccine trial. The responses to NY-ESO-1 in the combination vaccine study were comparable to the single vaccine. For responses to HER2, there were fewer antibody responses in the combination vaccines. Although there were marked individual variations in the antibody responses to the NY-ESO-1 and HER2 antigens, the reaction patterns to these antigens were comparable within each patient. Antibodies to OK-432 were not augmented. Protein cancer vaccines targeting multiple antigens are feasible.

[Case report of gastric cancer patient who suffered life-threatening adverse events including severe myelosuppression during neoadjuvant chemotherapy with S-1 and CDDP combination].

Neoadjuvant chemotherapy has been a recent focus in the treatment for advanced gastric cancer. Although the preoperative chemotherapeutic regimen of S-1 and CDDP is regarded as effective, safe and well tolerable according to previous clinical study, we experienced a 74-year-old woman who suffered from life-threatening adverse events including severe myelosuppression during the neoadjuvant chemotherapy. Although the patient did not experience any severe adverse events during the first course of treatment, on day 18 of the second course of chemotherapy, she was hospitalized because of anorexia and severe dehydration, leading to following grade 4 leukopenia/neutropenia, bacteremia, and disseminated intravascular coagulation (DIC). She finally recovered from the life-threatening adverse events with intensive therapy and eventually had a distal gastrectomy. Clinicians need to be alert especially to renal dysfunction that induces severe myelosuppression during chemotherapy with S-1, which contains 5-chloro-2,4-dihydroxypyridine (CDHP), a renal excretory inhibitor of dihydropyrimidine dehydrogenase (DPD).

Intra-arterial infusion chemotherapy with 5-fluorouracil and cisplatin in advanced pancreatic cancer: a feasibility study.

OBJECTIVE: Our aim was to examine the efficacy and tolerability of intra-arterial infusion chemotherapy with 5-fluorouracil (5-FU) and cisplatin in advanced pancreatic cancer. METHODS: Sixteen patients with unresectable locally advanced or metastatic pancreatic cancer (12 Stage IVa and 4 Stage IVb with liver metastasis) were enrolled. The catheter for intra-arterial infusion was placed at the position to distribute chemotherapeutic drugs to both the pancreatic tumor and the liver. Continuous infusion of 5-FU (250 mg/m(2) per day, 7 days) with intermittent bolus injection of cisplatin (5 mg/m(2) per day, 5 days) was repeated twice via the catheter, followed by intermittent injection of 5-FU (375 or 750 mg/m(2)) or cisplatin (7.5 mg/m(2)) once a week. The survival of these patients was compared with that of the matched historical control patients treated with other modalities. RESULTS: In 12 Stage IVa locally advanced patients, the response rate was 58.3% (7 partial response). The median survival time was 22.0 months, and the 1-, 2-, and 3-year survival rates were 83.3%, 41.7%, and 16.7%, respectively. The locally advanced patients treated with intra-arterial infusion chemotherapy showed significantly better survival than the control patients. In contrast, Stage IVb patients with liver metastasis showed no response to the treatment (response rate, 0%). Treatment was discontinued in 2 patients until recovery from hematologic or hepatic toxicity, but fatal adverse events were not observed. CONCLUSION: These results suggest that intra-arterial infusion chemotherapy with 5-FU and cisplatin is tolerable and feasible treatment to improve the prognosis in locally advanced pancreatic cancer patients without distant metastasis.

Preventive effect of a traditional herbal medicine, Hochu-ekki-to, on immunosuppression induced by surgical stress.

PURPOSE: To examine the effect of preoperative administering of a Japanese traditional herbal medicine, Hochu-ekki-to (TJ-41), on immunosuppression induced by surgical stress in patients with gastrointestinal malignancies. METHODS: To monitor the immune functions, the mitochondrial membrane potential (MMP) and natural killer (NK) cell activity prior to and following operation were measured in peripheral blood lymphocytes (PBL) in patients with (n = 20) or without (n = 27) the preoperative administering of TJ-41 for 7 days. The plasma catecholamine and interleukin (IL)-6 levels were also analyzed prior to and following the operation. RESULTS: The numbers of MMP-high CD56-positive cells (NK cells) and NK cell activities in the TJ-41-treated group were significantly higher than those in the control group (P = 0.026 and P = 0.037, respectively). An elevation of plasma noradrenaline and IL-6 following surgery was also inhibited by the preoperative administering of TJ-41 (P = 0.023 and P = 0.039, respectively). A positive correlation between MMP-high CD56-positive cell numbers and NK cell activity in PBL treated with carbonyl cyanide m-chlorophenyl hydrazone (CCCP) in vitro suggested that MMP measurement in CD56-positive cells can serve as a convenient alternative to evaluate the NK cell activity. CONCLUSION: Our findings suggest that the preoperative administering of TJ-41 prevents surgical stress-induced immunosuppression by maintaining the NK cell activity and inhibiting the elevation of stress mediators.

Uneventful splenectomy and cholecystectomy in a patient treated with anti-interleukin-6 receptor antibody therapy.

INTRODUCTION: Interleukin-6 (IL-6) is a multifunctional cytokine that regulates various aspects of the immune responses, acute phase reactions, and hematopoiesis. In rodent models, IL-6 has been suggested to be one of the essential mediators for optimal acute phase responses to infection and tissue damage. However, in humans, the roles of IL-6 in acute phase responses after surgery remain poorly understood. CASE REPORT: We present the first case report of successful splenectomy and cholecystectomy in a severe autoimmune-associated hemolytic anemia patient during treatment with a humanized anti-IL-6 receptor antibody. DISCUSSION: This unique case suggests that IL-6 is not an essential cytokine to safely perform surgical intervention and to prevent postoperative complications and that surgical intervention may not be contraindicated but can be selected as a therapeutic modality in patients treated with anti-IL-6 receptor antibody therapy.

n-Propyl gallate activates hypoxia-inducible factor 1 by modulating intracellular oxygen-sensing systems.

HIF-1 (hypoxia-inducible factor 1) is a master regulator of cellular adaptive responses to hypoxia. The expression and transcriptional activity of the HIF-1alpha subunit is stringently controlled by intracellular oxygen tension through the action of prolyl and asparaginyl hydroxylases. In the present study we demonstrate that PG (n-propyl gallate) activates HIF-1 and expression of its downstream target genes under normoxic conditions in cultured cells and in mice. The stability and transcriptional activity of HIF-1alpha are increased by PG. PG treatment inhibits the interaction between HIF-1alpha and VHL (von Hippel-Lindau protein) and promotes the interaction between HIF-1alpha and p300, indicating that PG inhibits the activity of both prolyl and asparaginyl HIF-1alpha hydroxylases. We conclude that PG activates HIF-1 and enhances the resultant gene expression by directly affecting the intracellular oxygen sensing system in vitro and in vivo and that PG represents a lead compound for the development of a non-toxic activator of HIF-1.

Prognostic significance of the immediate early response gene X-1 (IEX-1) expression in pancreatic cancer.

BACKGROUND: The immediate early response gene X-1 (IEX-1) is a stress-inducible protein that is involved in the regulation of cell proliferation and apoptosis. The aim of this study was to evaluate the prognostic significance of IEX-1 expression in pancreatic cancer. METHODS: IEX-1 protein expression was examined on paraffin-embedded specimens from 78 patients with pancreatic ductal adenocarcinoma using immunohistochemistry. The relationships between the IEX-1 expression and other clinicopathological parameters and patient survival were evaluated. A similar analysis was conducted in a subgroup of 48 patients, who underwent a macroscopically curative resection with detailed information on the pathological findings. RESULTS: Among 78 pancreatic cancer patients, 41 patients (53%) were positive for IEX-1 staining. In a multivariate analysis, curative operation (P < .001), pathological stage I-III (P = .001), and positive IEX-1 expression (P = .002) were significantly favorable factors for survival. In a subgroup of 48 patients undergoing a macroscopically curative surgery, IEX-1 expression was positive in 28 patients (58%). A significant negative correlation was observed between the IEX-1 expression and serosal (P = .032) or arterial (P = .040) invasion of tumors. A multivariate analysis demonstrated limited local invasion (pT1-3, P = .021), negative lymph node involvement (pN0, P < .001), and positive IEX-1 expression (P = .004) to be significantly favorable factors for survival. CONCLUSIONS: The positive IEX-1 expression in tumor tissues may be associated with a better prognosis in pancreatic cancer. An immunohistochemical assessment of IEX-1 expression may therefore be helpful for predicting patient prognosis in this disease.

Usefulness of 99mTc-sestamibi scintigraphy in suggesting the therapeutic effect of chemotherapy against gastric cancer.

PURPOSE: Imaging with (99m)Tc-sestamibi ((99m)Tc-MIBI) has been used to assess 170-kDa P-glycoprotein (P-gp) expression and predict chemotherapy responses in several types of malignancy, such as breast and lung cancers. The purpose of this study was to evaluate the relationship between (99m)Tc-MIBI accumulation in tumors and sensitivity to chemotherapy in gastric cancer patients. EXPERIMENTAL DESIGN: Thirty-six patients with advanced gastric cancer underwent (99m)Tc-MIBI scintigraphy before chemotherapy. Patients also underwent endoscopic biopsy, and the expression of P-gp or multidrug resistance-associated protein was analyzed by immunohistochemical staining. The relationship between the accumulation of (99m)Tc-MIBI in tumors and responses to chemotherapy with 5-fluorouracil/cis-diamminedichloroplatinum(II) or epirubicin was examined. RESULTS: Higher accumulation of (9m)Tc-MIBI in tumors was observed in 25 and 23 of 36 gastric cancer patients at the early (30 min) and delayed (120 min) images, respectively. Accelerated accumulation of (99m)Tc-MIBI negatively correlates with increased expression of P-gp, but not of multidrug resistance-associated protein, as determined by immunohistochemistry in gastric cancer tissues. The response rate to 5-fluorouracil/cis-diamminedichloroplatinum(II) chemotherapy in patients with high (99m)Tc-MIBI accumulation (15.4%) was much lower than that in patients with low (99m)Tc-MIBI accumulation (54.5%). In contrast, patients with high (99m)Tc-MIBI accumulation show a higher response rate (41.7%) to chemotherapy with epirubicin, which is known to be a substrate of P-gp transporter. CONCLUSIONS: (99m)Tc-MIBI scintigraphy is useful to suggest the responses to chemotherapy of patients with advanced gastric cancer.

CD4+CD25+ regulatory T cells in patients with gastrointestinal malignancies: possible involvement of regulatory T cells in disease progression.

BACKGROUND: Active suppression by CD4+CD25+ regulatory T cells plays an important role in the down-regulation of the response of T cells to foreign and self antigens. Experimental tumor models in mice revealed that regulatory T cells inhibit antitumor immune responses. The purpose of the current study was to demonstrate the possible involvement of CD4+CD25+ regulatory T cells in immune system impairment in patients with gastrointestinal malignancies. METHODS: The phenotypes of lymphocytes, particularly those of CD4+CD25+ T cells, were analyzed in peripheral blood in 149 patients with gastrointestinal malignancies and in ascites in 7 patients with peritoneal dissemination. In addition, cytokine production after in vitro stimulation was examined in CD4+CD25+ and CD4+CD25- T cells isolated from patients with malignant disease. RESULTS: Compared with healthy volunteers, patients with gastrointestinal malignancies had a higher proportion of CD4+CD25+ T cells in peripheral blood, due to the presence of a drastically smaller number of CD4+CD25- T cells. Among patients with gastric carcinoma, those with higher percentages of CD4+CD25+ T cells had a poorer prognosis than did those with lower percentages. CD4+CD25+ T cells also were present in greater proportions in ascites from patients who had advanced-stage disease with peritoneal dissemination. Isolated CD4+CD25+ T cells from patients with malignant disease produced interleukin (IL)-4 and IL-10 but not IL-2 or interferon-gamma; these cells also inhibited cytokine production by CD4+CD25- T cells after in vitro stimulation. CONCLUSIONS: The relative increase in CD4+CD25+ regulatory T cells may be related to immunosuppression and tumor progression in patients with gastrointestinal malignancies. This finding suggests that the use of immunomodulatory therapy to treat patients with gastrointestinal malignancies may be an effective strategy.

Change in mitochondrial membrane potential in peripheral blood lymphocytes, especially in natural killer cells, is a possible marker for surgical stress on the immune system.

There is accumulating evidence that surgical stresses cause impairment of systemic immune responses, which may promote susceptibility to infection as well as growth of remnant cancer cells in cancer patients. Although alterations in numbers, populations, and functions of lymphocytes have been extensively studied to assess modulation of the immune system, the precise mechanisms of immunosuppression caused by surgical stresses have not been identified, nor have methods been developed to estimate the magnitude of surgical stresses on the immune system. In the present study, to evaluate the effects of surgical procedures on the immune system, the mitochondrial membrane potential (Delta Psi(m)) of peripheral blood lymphocytes (PBL) from 25 patients who underwent various types of operation was measured by flow cytometry using 3,3'-dihexiloxacarbocyanine iodide (DiOC(6)(3)) on the day before operation and on postoperative day (POD) 1, POD 3, and POD 7. The Delta Psi(m) in PBL, especially in natural killer (NK) cell population, was reduced after major surgery. In particular, the reduction of Psi Delta(m) in NK cells appeared to be proportional to the severity of the surgical procedures and reflected the impairment of cellular function. Interestingly, the Delta Psi(m) in NK cells was also negatively correlated with the level of plasma noradrenaline after major surgery, suggesting that the reduction of Delta Psi(m) in NK cells induced by surgical stresses may be mediated, at least in part, by the accompanying increase in plasma noradrenaline. Monitoring of Delta Psi(m) in PBL after operation may be one of the useful markers for estimating the magnitude of surgical stresses on the immune system.

Tuberculous lymphadenitis as a cause of obstructive jaundice: report of a case.

We report a rare case of obstructive jaundice caused by enlarged tuberculous lymph nodes compressing the common bile duct in the retropancreatic region, mimicking pancreatic cancer. A 32-year-old man was admitted to our hospital with a 1-month of history of jaundice. An abdominal computed tomography (CT) scan showed a tumor in the pancreatic head, but an endoscopic retrograde cholangiopancreatogram (ERCP) showed a normal pancreatic duct system. Positron emission tomography with 2-[fluorine-18]-fluoro-2-deoxy- d-glucose (FDG-PET) revealed a hot spot only in the pancreatic head. Under a presumptive diagnosis of malignancy, a laparotomy was performed and an intraoperative biopsy specimen revealed epithelioid granuloma with caseous necrosis, which led us to suspect tuberculous lymphadenitis. This diagnosis was confirmed by culture, and antituberculous therapy was commenced postoperatively. The patient has not suffered any further episodes of obstructive jaundice. This case report demonstrates that positive FDG-PET results should be interpreted carefully when diagnosing tumors of the pancreatic head.

[A case of recurrent advanced gastric cancer suggesting the efficacy of TS-1 and CDDP combination chemotherapy].

The patient, a 53-year-old male, underwent radical surgery for advanced gastric cancer (stage IV). On the second day after surgery, adjuvant chemotherapy consisting of 250 mg/day 5-FU (i.v.) for 14 days, followed by 450 mg/day of UFT-E for about 12 months, was initiated. About 21 months after surgery (7 months after cessation of medication), the CA19-9 level had risen (136 U/ml). After 26 months, the patient experienced a backache and his CEA and CA19-9 levels had risen 11.7 ng/ml and 869 U/ml, respectively. The results from an imaging examination were suggestive of multiple bone metastases and para-aortic lymphatic metastasis. Chemotherapy was resumed with only TS-1 (100 mg/day). Because the tumor markers (TM) continued to rise, he was hospitalized and the medication was combined with daily administration of 10 mg of CDDP (TS-1 + CDDP protocol). When the total dose of CDDP reached 160 mg, there was a dramatic drop in the TM (surrogate marker) level. The patient was discharged and medication of TS-1 and 10 mg/day of CDDP twice a week was continued on an outpatient basis. Five months after the initial administration of FP, the CEA and CA19-9 returned to normal levels (4.3 ng/ml and 33 U/ml, respectively). Metastases to the para-aortic lymph nodes had disappeared and the sites of bone metastases were reduced in size. The patient was able to resume his full social activities. Since that time, a second-line therapy has been added. Currently (about two years after the recurrence), he is still undergoing therapy with TS-1 + CDDP.

Usefulness of FDG-positron emission tomography in diagnosing peritoneal recurrence of colorectal cancer.

BACKGROUND: Accurate detection of peritoneal recurrence in colorectal cancer remains a diagnostic challenge. We retrospectively examined sensitivity and accuracy of fluorine-18-2-fluoro-deoxy-D-glucose positron emission tomography (FDG-PET) in the diagnosis of peritoneal recurrence. METHODS: FDG-PET and computed tomography (CT) were performed on 23 patients with colorectal cancer suspected of having a recurrence based on clinical symptoms, a tumor marker (CEA), and so forth. The final diagnosis was compared with the results of FDG-PET and CT. RESULTS: Peritoneal recurrence was suspected in 6 patients with FDG-PET, and 5 of them were finally diagnosed as recurrences. The sensitivity of FDG-PET was 88% and its diagnostic accuracy was 78%, whereas those of CT were 38% and 44%, respectively. A lesion as small as 15 mm in diameter was diagnosed by FDG-PET. CONCLUSIONS: FDG-PET is an effective method for diagnosing peritoneal recurrence of colorectal cancer. FDG-PET is expected to become more important for detecting peritoneal recurrence at an early stage.

Surgical stress during operation for gastrointestinal cancer increases plasma thioredoxin levels and decreases mitochondrial membrane potential in peripheral blood lymphocytes.

Surgical stress is difficult to evaluate quantitatively. It has been reported that mitochondrial membrane potential (delta psi(m)) in the peripheral blood lymphocytes (PBLs) is decreased by surgical stress. Thioredoxin (TRX), a small protein with redox-active dithiol/disulfide in the active site, is induced by a variety of oxidative stresses and secreted from the cells. Accumulating evidence shows that plasma levels of TRX are elevated in oxidative stress-associated disorders. In the present study, we examined plasma levels of TRX in cases undergoing operations for gastrointestinal cancer. Plasma levels of TRX were significantly elevated on the first postoperative day compared with the pre-operative levels. The changes in the plasma TRX levels tended to show an inverse relationship with the changes in delta psi(m) in PBLs, which shows a significant decrease caused by surgical stress. Plasma TRX levels as well as delta psi(m) in PBLs are valuable markers to evaluate surgical stress.

Role of retinoblastoma protein and E2F-1 transcription factor in the acquisition of 5-fluorouracil resistance by colon cancer cells.

5-fluorouracil (5-FU) is an important antineoplastic agent that has proven to be effective in the treatment of colorectal cancer. However, one of the main obstacles to the clinical use of 5-FU is the acquisition of resistance to the drug by cancer cells. In vitro studies have demonstrated that the resistance to 5-FU is correlated with increased activity of thymidylate synthase (TS), whose gene has a E2F binding site in its promoter region. To understand the mechanisms through which cancer cells acquire resistance to 5-FU, human colon cancer-derived cell line DLD-1 and its subcloned cell line DLD-1/5-FU, which has acquired resistance to 5-FU, were compared by assessing their phosphorylation of retinoblastoma protein (pRb) and E2F-1 transcriptional activity. The level of pRb phosphorylation in the DLD-1/5-FU cells was higher than in the parental DLD-1cells. In parallel with the increased phosphorylation of pRb, E2F-1 transcriptional activity, which has been shown to be a result of E2F-1 dissociation from hyperphosphorylated pRb, was increased in the DLD-1/5-FU cells. Examination of the effect of E2F-1 decoy oligodeoxynucleotides (ODNs) on the proliferation of DLD-1/5-FU cells in the presence of 5-FU to confirm the importance of E2F-1 in the mechanisms of the acquisition of 5-FU resistance showed that DLD-1/5-FU cells transfected with E2F-1 decoy ODNs recovered their sensitivity to 5-FU. These results suggested that pRb and E2F-1 play important roles in the acquisition of 5-FU resistance by cancer cells and that cancer therapy targeting transcription factor E2F might be effective.

Mitochondrial membrane potential is reduced in peripheral natural killer cells following partial hepatectomy.

The mechanism underlying immunosuppression after partial hepatectomy remains unclear. Hepatectomy induces lymphopenia, which is related to immunomodulation. The aim of this study was to determine whether peripheral blood lymphocytes (PBL) are susceptible to mitochondria-mediated apoptosis after hepatic resection. We compared the changes in mitochondrial membrane potential in lymphocytes from hepatectomized patients with metastatic liver tumor with the corresponding changes in lymphocytes from cholechystectomized patients, because changes in mitochondrial membrane potential have been reported to frequently occur during the early stages of apoptosis. Mitochondrial membrane potential, subpopulation, and apoptosis of lymphocytes were estimated with flow cytometry. Hepatectomy significantly (P<0.001) reduced postoperative mitochondrial membrane potential, while cholecystectomy slightly decreased it. Apoptosis of lymphocytes was increased on post-hepatectomy day, and this increase was correlated with the extent of mitochondrial membrane potential reduction. The major subset of lymphocytes with low mitochondrial membrane potential consisted of CD56(+) natural killer (NK) cells, and NK cell activity and cell counts significantly decreased after hepatectomy. Mitochondrial membrane potential of PBL was reduced after hepatectomy, and some lymphocytes underwent apoptosis through the mitochondrial pathway, which was one of the causes for lymphopenia. NK cells were more responsible for the decrease of mitochondrial membrane potential after hepatectomy than other lymphocytes, and the reduction in mitochondrial membrane potential in NK cells appeared to reflect modulation of the innate immune system.

Aminopeptidase N is involved in cell motility and angiogenesis: its clinical significance in human colon cancer.

BACKGROUND & AIMS: The molecular basis of cell motility is highly complex and is controlled by a number of molecular systems, whereas angiogenesis is an important biological component of tumor progression. The aims of this study were to investigate the possible involvement of proteins at the cell surface in controlling cell motility and angiogenesis, and to identify the cell surface molecules involved in gastrointestinal tumors. METHODS: We addressed these issues using functional monoclonal antibodies, which inhibit cell motility, endothelial cell migration, and tube formation. Furthermore, we investigated the relationship between this antigen and colon cancer, and showed the prognostic significance in human colon cancer. RESULTS: We established a murine monoclonal antibody MH8-11, which inhibits cell motility and in vitro angiogenesis. This epitope was a 165-kilodalton protein, and the sequencing analysis revealed that it was almost identical to aminopeptidase N (APN)/cluster of differentiation (CD) 13. APN/CD13 expression was associated with tumor status (P = 0.025). The disease-free and overall survival rate for patients with positive APN/CD13 expression tumors was significantly lower than that for patients with negative APN/CD13 expression tumors (P = 0.014, 0.033, respectively). Among 47 node-positive patients, the survival rate of patients with negative APN/CD13 expression was better than that of those with positive APN/CD13 expression. CONCLUSIONS: Our data suggest that APN/CD13 is involved in cell motility and angiogenesis, and APN/CD13 expression may be a useful indicator of a poor prognosis for node-positive patients with colon cancer.