Phase I clinical trial of 99mTc-etarfolatide, an imaging agent for folate receptor in healthy Japanese adults.

OBJECTIVE: Technetium etarfolatide ((99m)Tc-EF) is a radioactive diagnostic imaging agent that was developed to assess the expression of folate receptors in tumors. Administering folic acid prior to the administration of (99m)Tc-EF has been shown to improve SPECT images. Here, we conducted a phase I clinical trial to assess the safety, pharmacokinetics, and radiation dosimetry of (99m)Tc-EF injection following pre-administration of folic acid in healthy Japanese male adults. METHODS: Six healthy Japanese male adults were enrolled in the study. Folic acid was intravenously administered, followed 1-3 min later by an intravenous injection of (99m)Tc-EF (740 MBq ± 20 %). Assessments of subjective symptoms and objective findings, electrocardiograms, physical examination, and laboratory tests were performed before and up to 7 days after the injection to assess the safety of (99m)Tc-EF. Blood and urine collections and whole-body planar imaging were conducted at various time points up to 24 h after the injection to assess the pharmacokinetics of (99m)Tc-EF. The internal radiation dosimetry was calculated based on the pharmacokinetics results using the MIRD method. RESULTS: Five adverse events were observed in three subjects (50 %) after administration of the folic acid and (99m)Tc-EF, while these events were mild and non-serious. Of those five events, three were considered to be related to the administered agents. The radioactivity in blood rapidly decreased and showed a biphasic profile. The activity of (99m)Tc-EF at 5 min post injection was largest in the bone marrow, followed by the liver and kidneys, and had decreased within 24 h in all organs/tissues without appreciable retention. The pharmacokinetics results suggested that (99m)Tc-EF was mainly eliminated by kidney. The results also suggested that when administered at 925 MBq of (99m)Tc-EF, which is the maximum dose generally used for clinical trials in other countries, the corresponding effective dose of (99m)Tc-EF is equal to or less than those determined for the current radioactive diagnostic imaging agents. CONCLUSIONS: The results of this study assessing the safety and radiation dosimetry of (99m)Tc-EF with folic acid pre-administration suggested that folic acid and (99m)Tc-EF should be appropriate for further studies. No pharmacokinetics concerns were noted.

Clinical relevance of the number of interleukin-17-producing CD 8+ T cells in patients with gastric cancer.

PURPOSE: There is accumulating evidence that inflammation is linked to cancer development and progression. Interleukin-17 (IL-17), an inflammatory cytokine, is produced by CD 8+ T cells (Tc17 cells); however, the specific role of Tc17 cells in tumor immunity against gastric cancer remains unclear. METHODS: The prevalence of Tc17 cells in both peripheral blood mononuclear cells and gastric tissue was evaluated by multicolor flow cytometry and the concentration of IL-17 in sera was quantitated by an enzyme-linked immunosorbent assay. RESULTS: Circulating Tc17 cells were significantly more numerous in gastric cancer patients than in controls, and significantly more numerous before surgery than after surgery. IL-17 concentrations in gastric cancer patients and healthy controls were 0.51 ± 0.54 and 0.084 ± 0.084 pg/mL, respectively, with this difference being significant. The percentage of Tc17 cells was significantly related to serum IL-17 concentration. Tc17 cells were significantly more numerous than peripheral blood mononuclear cells in gastric cancer tissue. Furthermore, Tc17 cells were more numerous in cancerous gastric tissue than in normal gastric tissue. CONCLUSIONS: Tc17 cells may be the main source of IL-17 in gastric cancer patients and thus involved in the progression of gastric cancer.

Acquired resistance to gemcitabine and cross-resistance in human pancreatic cancer clones.

The efficacy of gemcitabine (GEM), a standard treatment agent for pancreatic cancer, is insufficient because of primary or acquired resistance to this drug. Patients with tumors intrinsically sensitive to GEM gradually acquire resistance and require a shift to second agents, which are associated with the risk of cross-resistance. However, whether cross-resistance is actually present has long been disputed. Using six GEM-resistant and four highly GEM-resistant clones derived from the pancreatic cancer cell line BxPC-3, we determined the resistance of each clone and parent cell line to GEM and four anticancer agents (5-FU, CDDP, CPT-11, and DTX). The GEM-resistant clones had different resistances to GEM and other agents, and did not develop a specific pattern of cross-resistance. This result shows that tumor cells are heterogeneous. However, all highly GEM-resistant clones presented overexpression of ribonucleotide reductase subunit M1 (RRM1), a target enzyme for metabolized GEM, and showed cross-resistance with 5-FU. The expression level of RRM1 was high; therefore, resistance to GEM was high. We showed that a tumor cell acquired resistance to GEM, and cross-resistance developed in one clone. These results suggest that only cells with certain mechanisms for high-level resistance to GEM survive against selective pressure applied by highly concentrated GEM. RRM1 may be one of the few factors that can induce high resistance to GEM and a suitable therapeutic target for GEM-resistant pancreatic cancer.

Pathogenic mutation of ALK2 inhibits induced pluripotent stem cell reprogramming and maintenance: mechanisms of reprogramming and strategy for drug identification.

Fibrodysplasia ossificans progressiva (FOP) is a rare congenital disorder characterized by progressive ossification of soft tissues. FOP is caused by mutations in activin receptor-like kinase 2 (ALK2) that cause its constitutive activation and result in dysregulation of BMP signaling. Here, we show that generation of induced pluripotent stem cells (iPSCs) from FOP-derived skin fibroblasts is repressed because of incomplete reprogramming and inhibition of iPSC maintenance. This repression was mostly overcome by specific suppression of ALK2 expression and treatment with an ALK2 inhibitor, indicating that the inhibition of iPSC generation and maintenance observed in FOP-derived skin fibroblasts results from constitutive activation of ALK2. Using this system, we identified an ALK2 inhibitor as a potential candidate for future drug development. This study highlights the potential of the inhibited production and maintenance of iPSCs seen in diseases as a useful phenotype not only for studying the molecular mechanisms underlying iPS reprogramming but also for identifying drug candidates for future therapies.

Prevalence and clinical relevance of Th17 cells in patients with gastric cancer.

BACKGROUND: Th17 cells have recently been identified as a distinct T helper (Th) lineage in a cancer animal model and in human cancers. Their specific role in tumor immunity is unclear. We, therefore, sought to evaluate the role of Th17 cells in gastric cancer. METHODS: The prevalence of Th1, Th2, Treg, and Th17 cells in both peripheral blood mononuclear cells (PBMC) and gastric tissue was evaluated by multicolor flow cytometry. The concentration of interleukin (IL)-17 in sera was quantitated by enzyme-linked immunosorbent assay. RESULTS: We observed a clear difference in the prevalence of Th17 cells in PBMC (0.34 ± 0.24%) versus gastric cancer tissues (19.4 ± 12.1) (P = 0.0002). Subset-specific phenotypic analysis of CD4+ T cells in both PBMC and gastric cancer tissue showed that Th1 and Treg cells predominate in PBMC, whereas Th17 cells are the most abundant CD4+ T cell subset in cancerous tissue. The concentrations of IL-17, a hallmark of Th17, in gastric cancer patients and normal controls were 0.6 ± 0.67 and 0.16 ± 0.19 pg/mL (P = 0.0032). Five-year survival rates of patients with high IL-17 and low IL-17 concentration were 47.1% and 83.9% (P = 0.0075). Multivariate analysis indicated that IL-17 concentration was an independent prognostic indicator, as well as lymph node metastasis. CONCLUSIONS: There was a significant skewing toward a Th17 phenotype in gastric cancer tissue. IL-17 seems to play an important role in the progression of gastric cancer.

Effect of a combination of S-1 and gemcitabine on cell cycle regulation in pancreatic cancer cell lines.

In a previous study, we showed that a combination of an oral fluoropyrimidine anticancer agent (S-1) and gemcitabine (GEM) had synergistic effects on cell growth and cell cycle arrest in the pancreatic cancer cell line MIA PaCa-2. Therefore, we conducted further mechanistic studies using the pancreatic cancer cell lines MIA PaCa-2 and SUIT-2. The combined effect of S-1 and GEM in SUIT-2 cells was evaluated using an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and the effects of S-1, GEM and S-1 plus GEM on cell cycle regulation were assessed using flow cytometry. We also examined the expression of several cell cycle regulatory proteins in both MIA PaCa-2 and SUIT-2 cells by western blotting. Classical isobolographic analysis of the MTT assay results showed that the combination of S-1 and GEM had a synergistic effect in SUIT-2 cells, and flow cytometric analysis of the cell cycle showed that the combination of S-1 plus GEM induced S-phase arrest to a greater degree than did either S-1 or GEM alone. Also, the combination of S-1 and GEM resulted in the downregulation of cyclin D1 expression and upregulation of cyclin A, p21 and p27 expression levels. Treatment of MIA PaCa-2 and SUIT-2 cells with a combination of both drugs also led to the increased phosphorylation of checkpoint kinase 1. Combined treatment with S-1 and GEM resulted in more prolonged S-phase arrest than with either treatment alone. This difference is shown to be potentially due to the higher levels of phosphorylated checkpoint kinase 1 in pancreatic cancer cell lines treated with the two agents.

Retrospective analysis of prognostic outcome of gastric cancer in young patients.

BACKGROUND: It has been suggested that gastric cancer in young patients has a worse prognosis than in older patients, but this is controversial. This retrospective investigation was undertaken to understand the clinicopathological features and identify the prognostic factors of gastric cancer in young patients. METHODS: Patients included in this study were those treated and followed up for gastric cancer from 1989 to 2005. Operative records, clinical, pathological, and follow-up data were reviewed. The critical age cut-off value for obtaining distinctive prognoses was 34 years. RESULTS: Of 1730 gastric cancer patients whose records were reviewed, 27 were less than 34 years old (YGC group). The YGC group contained significantly higher percentages of females, stage IV, macroscopic type 4 tumors, poorly differentiated histology, peritoneal dissemination, and epigastric pain symptoms than the gastric cancer group aged 34 years or more (OGC group). Survival in the YGC group was significantly worse than in the OGC group (p = 0.0363). Ten-year survival was 68.5% in the YGC group and 81.8% in the OGC group. Survival in the YGC group was poorer for the stage IV patients, compared with OGC patients, especially for the stage IV patients with peritoneal dissemination and without liver metastases (H0P1 patients) (p = 0.049). CONCLUSIONS: Age in gastric cancer affects the prognosis, which in gastric cancer patients less than 34 years old was significantly poorer than for older patients, because of the high incidence of stage IV cancer with peritoneal dissemination in gastric cancer patients less than 34 years old.

Serum interleukin-6 and -10 levels in patients with gastric cancer.

BACKGROUND: Interleukin-6 (IL-6) is known to be a multifunctional cytokine and IL-10 is an immunosuppressive factor. Both have been reported to be related to the disease prognosis in some human solid tumors. In the present study, we evaluated the clinical significance of preoperative serum IL-6 and IL-10 levels as new tumor markers in patients with gastric cancer (GC). METHODS: Preoperative serum samples from 90 patients with GC and 9 normal healthy volunteers were assayed. Levels of IL-6 and IL-10 were determined by enzyme-linked immunosorbent assay (ELISA). The clinical significance of serum IL-6 and IL-10 levels was evaluated and compared with serum carcinoembryonic antigen (CEA) levels and serum C-reactive protein (CRP) levels in these patients. RESULTS: The serum level of IL-6 was significantly higher in the GC patients than in the healthy subjects. Serum IL-6 levels were strongly correlated with CRP levels, but did not correlate with CEA or carbohydrate antigen (CA) 19-9 levels. Serum IL-10 levels did not correlate with CEA, CA19-9, or CRP. Strong positive correlations between serum IL-6 levels and tumor size and tumor stage were observed. On the other hand, IL-10 did not correlate with such clinicopathological findings of tumors. However, high serum IL-10 levels were associated with a worse prognosis in the GC patients, independently of their tumor stage. CONCLUSION: These findings indicate that serum IL-6 may suggest gastric cancer progression. On the other hand, IL-10 may play an important role in host immunity and the prognosis of GC patients.

Experimental study of combination therapy with S-1 against pancreatic cancer.

PURPOSE: To determine the most effective combination chemotherapy with S-1 against pancreatic cancer and to clarify the mechanism of synergy between S-1 and the partner drug. METHODS: We tested a combination of S-1 with the following antitumor drugs in an in vitro MTT assay against pancreatic cancer cell line MIA PaCa-2: gemcitabine (GEM), cisplatin (CDDP), irinotecan (CPT-11), mitomycin C, adriamycin, and paclitaxel. The efficacy of S-1, GEM, and a combination of S-1 and GEM was also tested in vivo by administering S-1 (10 mg/kg) orally to nude mice five times a week for 3 weeks, and GEM (100 mg/kg) intravenously every 2-3 days for a total of six times. A treated-to-control ratio (T/C) of relative mean tumor weight values less than 50% was determined to be effective. Furthermore, we investigated the mechanism of the synergistic effect of S-1 and GEM on the cell cycle by flow cytometry, because both S-1 and GEM are known as antimetabolic drugs. To verify cell death induced by a change in the distribution of the cell cycle phases, we investigated apoptosis by sub-G1 analysis and a TUNEL assay. RESULTS: From classical isobolography analysis of the in vitro MTT assay, the combination of S-1 plus GEM was found to be the most effective of the combinations tested. In vivo, T/C (percentage) with the combination of S-1 plus GEM was 48.2%, which was lower than that of S-1 or GEM alone, and the combination enhanced antitumor activity. Cell cycle analysis showed greater cell cycle delay with the combination treatment (S-1 plus GEM) than for each single drug treatment, and apoptotic cells were detected only in treatments including GEM. CONCLUSION: The combination chemotherapy of S-1 and GEM appears to be useful for pancreatic cancer. Both cycle delay by S-1 plus GEM and apoptosis induced by GEM are involved in this synergistic mechanism.

Clinicopathologic characteristics of gastric cancer patients who underwent noncurative gastrectomy with long-term survival.

PURPOSE: To demonstrate clinicopathologic characteristics of gastric cancer patients who underwent noncurative gastrectomy with long-term survival. METHODS: We retrospectively reviewed 202 advanced gastric cancer patients who underwent noncurative gastrectomy. RESULTS: The long-term survivors who survived for more than 3 years comprised four of 65 patients with a residual tumor in the peritoneum, one of 50 patients with a residual tumor from lymph node metastasis, three of 41 patients positive for the resected margin (M-factor) and 17 of 153 patients with free intraperitoneal cancer cells (Cy-factor). Multivariate analysis indicated that independent indicators affecting survival were lymph node metastasis and peritoneal metastasis in patients with the Cy-factor and histology in patients with the M-factor. CONCLUSIONS: Long-term survival can only be expected in patients with the Cy-factor who have neither macroscopic peritoneal metastasis nor lymph node metastasis or in patients with the M-factor who have a well-differentiated tumor.

Prognostic significance of the ratio between metastatic and dissected lymph nodes (n ratio) in patients with advanced gastric cancer.

BACKGROUND AND OBJECTIVES: To determine the prognostic significance of the ratio between metastatic and dissected lymph nodes (n ratio) in gastric cancer patients. METHODS: We retrospectively reviewed 777 advanced gastric cancer patients who had undergone curative gastrectomy at our hospital. RESULTS: The n ratio was significantly greater in cases with a large tumor, undifferentiated tumor, lymphatic vessel invasion, or blood vessel invasion. Furthermore, the n ratio was significantly correlated with the depth of invasion, level of lymph node metastasis, and number of lymph node metastases. The prognosis for gastric cancer patients correlated well with the n ratio. Multivariate analysis indicated that the n ratio, but not the number of lymph node metastases, was an independent prognostic indicator. Moreover, the n ratio was an independent prognostic factor in N1, N2, and N3 patients defined by the Japanese Classification of Gastric Cancer (JCGC). CONCLUSIONS: The n ratio is useful for evaluating the status of lymph node metastasis in gastric cancer. Therefore, the addition of the n ratio to the N (nodal) category defined by the JCGC may be a useful strategy in the N-staging classification of gastric cancer.

Pharmacokinetics and postoperative analgesia of epidural tramadol: A prospective, pilot study.

BACKGROUND: Tramadol, a centrally acting analgesic drug, can be administered via multiple routes and is generally well tolerated. OBJECTIVE: This study was designed to assess the pharmacokinetics of epidural tramadol administered preoperatively in Japanese patients undergoing upper abdominal surgery. METHOD: Japanese patients who were scheduled to undergo upper abdominal surgery in The Kitasato Institute Hospital, Tokyo, Japan, were included. Patients received tramadol 2 mg/kg with 5 mL of 1% mepivacaine epidurally 10 minutes before incision. The serum concentration of tramadol was determined by high-performance liquid chromatography for 21 hours after administration. Serum concentration was determined before tramadol administration and 10, 20, 30, and 60 minutes after tramadol administration, first postoperative night, and first postoperative day. Pain score and adverse events (AEs) were assessed at 1, 3, 6, 12, 18, 24, 36, and 48 hours after surgery by patient interview. RESULTS: Eleven patients were assessed for enrollment. Seven patients (6 men, 1 woman; mean [SD] age, 61.3 [12.6] years; mean [SD] weight, 59.9 [8.9] kg) provided consent and completed the study. The mean (SD) serum Cmax of tramadol was 1385.5 (390.8) ng/mL, Tmax was 0.33 (0.22) hour, and terminal elimination half-life (t1/2ß) was 10.5 (2.3) hours. Four patients complained of nausea; however, only 1 patient was administered an antiemetic. No other AEs were reported. CONCLUSION: This pilot study found that epidural tramadol administered before incision induced a Cmax within 30 minutes of administration. The drug was detected in serum at ∼21 hours after surgery.

Laparoscopic resection for malignant lymphoma of the ileum causing ileocecal intussusception.

A 22-year-old man was admitted with right lower abdominal pain. Colonoscopy revealed a ball-like tumor at the ileum. Abdominal sonography and computed tomography showed ileocecal intussusception. Microscopic examination of the biopsy specimen showed malignant lymphoma. Laparoscopic ileocecal resection was performed. Histologic diagnosis of the resected tumor was diffuse large B cell-type malignant lymphoma. Intussusception due to malignant lymphoma is relatively rare in adults. If contraindications of laparoscopy are not present, laparoscopic resection can be performed safely and should be considered for diagnosis and treatment for intussusception in ileocecal lesions in adults.

[Experimental chemotherapy against human esophageal carcinoma xenografts with TS-1, cisplatin and docetaxel].

Three strains of human esophageal carcinoma xenografts established in our institution were tested against combination chemotherapy in vivo and in vitro. TS-1 plus cisplatin (CDDP) was shown to be an effective combination against two carcinoma strains of moderately-differentiated type. Determination of the thymidylate synthase (TS) demonstrated a higher inhibition of the enzyme by adding CDDP to 5-FU, suggesting biochemical modulation. The remaining strain of poorly-differentiated type was resistant to the combination and an attempt was made to add docetaxel (DTX) to show that the three-drug combination was effective against the strain. Combination chemotherapy including TS-1 and CDDP thus appears to be useful treatment choice for esophageal carcinoma.

TZT-1027 elucidates antitumor activity through direct cytotoxicity and selective blockade of blood supply.

BACKGROUND: TZT-1027 is a newly developed antitumor agent derived from dolastatin 10. MATERIALS AND METHODS: The in vitro activity of TZT-1027 on MCF-7 and R-27 cells was evaluated by MTT assay. TZT-1027 1 mg/kg/week was administered i.v. for 4 weeks into nude mice bearing MCF-7 and R-27. Subsequently, primary cultured cells from xenografts were also used for CD-DST. Two mg of TZT-1027 or 40 mg docetaxel per kg were injected i.v. into nude mice bearing R-27. 0.2% Evans blue was injected to assess the blood flow. RESULTS: TZT-1027 suppressed the in vitro growth of MCF-7 cells, while R-27 cells were resistant to TZT-1027, although its in vivo antitumor activity was remarkable. TZT-1027 blockaded R-27 tumor blood flow immediately after injection; blood flow was not affected by docetaxel. CONCLUSION: TZT-1027 exerts its antitumor activity through direct cytotoxicity against MCF-7 cells and through selective blockade of tumor blood flow against R-27 cells.