Nucleobases are important compounds that constitute nucleosides and nucleic acids. Although it has long been suggested that specific transporters are involved in their intestinal absorption and uptake in other tissues, none of their molecular entities have been identified in mammals to date. We here describe identification of rat Slc23a4 as the first sodium-dependent nucleobase transporter (rSNBT1). The mRNA of rSNBT1 was expressed highly and only in the small intestine. When transiently expressed in HEK293 cells, rSNBT1 could transport uracil most efficiently. The transport of uracil mediated by rSNBT1 was sodium-dependent and saturable with a Michaelis constant of 21.2 muM. Thymine, guanine, hypoxanthine and xanthine were also transported, but adenine was not. It was also suggested by studies of the inhibitory effect on rSNBT1-mediated uracil transport that several nucleobase analogs such as 5-fluorouracil are recognized by rSNBT1, but cytosine and nucleosides are not or only poorly. Furthermore, rSNBT1 fused with green fluorescent protein was mainly localized at the apical membrane, when stably expressed in polarized MDCKII cells. These characteristics of rSNBT1 were almost fully in agreement with those of the carrier-mediated transport system involved in intestinal uracil uptake. Therefore, it is likely that rSNBT1 is its molecular entity or at least in part responsible for that. It was also found that the gene orthologous to the rSNBT1 gene is genetically defective in human. This may have a biological and evolutional meaning in the transport and metabolism of nucleobases. The present study provides novel insights into the specific transport and metabolism of nucleobases and their analogs for therapeutic use. less...

OBJECTIVES:: A phase II study was carried out to assess the efficacy and toxicity of combination chemotherapy with irinotecan, 5-fluorouracil (5-FU), and leucovorin (FOLFIRI) for the treatment of patients with metastatic or recurring gastric cancer previously treated with fluoropyrimidine-based chemotherapy. METHODS:: Eligible patients were those who had metastatic gastric cancer previously treated with a fluoropyrimidine-based chemotherapy regimen or had disease recurrence within 6 months of completing adjuvant fluoropyrimidine-containing chemotherapy. Participants received irinotecan (150 mg/m on day 1) and leucovorin (LV; 20 mg/m on days 1-2) followed by continuous infusion of 5-FU (1500 mg/m on days 1-2), every 2 weeks. RESULTS:: Between April 2006 and March 2008, 33 patients were enrolled in the study. FOLFIRI served as a second-line treatment in 27 patients, third-line treatment in 4 patients, and fourth-line treatment in 2 patients. The patients had a median age of 60 years (range, 40-75) and underwent 132 cycles of chemotherapy, with a median of 3 cycles (range, 1-15) per patient. The response rate was 18.2%, and the disease control rate was 36%. Median overall survival was 5.1 months (95% confidence interval, 3.74-6.45), and median time to progression was 2.3 months (95% confidence interval, 1.81-2.78). The major grade 3-4 toxicity was neutropenia (45.4%). CONCLUSION:: Combination chemotherapy with irinotecan, 5-FU, and LV is feasible in gastric cancer patients previously treated with fluoropyrimidine-based chemotherapy. less...

OBJECTIVES:: The aim of this study was to evaluate the efficacy and safety profile of 4 dose-dense cycles of docetaxel followed by 3 cycles of FEC100 neoadjuvant chemotherapy in patients with operable advanced breast cancer. METHODS:: Women were treated by 4 cycles of 100 mg/m docetaxel every 2 weeks, followed by 3 cycles of FEC100 given every 3 weeks. The primary end point was pathologic complete response. RESULTS:: Forty-five patients were treated. Ninety-three percent of the patients completed the planned 7 chemotherapy courses. The median relative dose intensity for docetaxel, 5-fluorouracil, epirubicin, and cyclophosphamide were 0.98, 0.97, 0.96, and 0.97, respectively. There were no therapy-related deaths. Two patients stopped chemotherapy because of cutaneous toxicity. During the docetaxel sequence, the most common grade 3-4 toxicities were (% pts): neutropenia (13.3), grade 3: cutaneous (24.4), myalgia and arthralgia (6.7). No clinical cardiac toxicity was observed. The pathologic complete response rate was 21.4% and 26.2% using Sataloff and Chevallier classifications, respectively. The conservative surgery rate was 62.2%. The median follow-up was 38.5 months. Two and 3-year disease-free survival rates were 79% and 64%, respectively. Two- and 3-year overall survival rate were 93% and 88%, respectively. CONCLUSIONS:: This trial confirms the feasibility and efficacy of this dose dense docetaxel neoadjuvant regimen. less...

Gemcitabine (Gem) is a dFdC analogue with activity against several solid tumors. Gem is intracellularly phosphorylated by dCK, leading to the production of the metabolite dFdCDP. dFdCDP exhibits the cytotoxic effect by inactivating ribonucleotide reductase larger subunit 1 (RRM1), which is a rate limiting enzyme for de novo DNA synthesis. To date, RRM1 expression is believed to determine sensitivity to Gem in pancreatic and non-small cell lung cancer. In the present study, we found that an anti-allergic drug, tranilast strongly enhanced the sensitivity of pancreatic cancer cell line KP4 to Gem. In growth inhibition assay, 100 microM of tranilast plus 1 microM of Gem more strongly suppressed the growth of KP4 at 12.7-fold in IC50 than single Gem treatment, while this compound no longer affected the sensitivity to other drugs such as 5-fluorouracil, irinotecan or paclitaxel. FACS and TUNEL analysis demonstrated the increased apoptotic population in KP4 cells under tranilast plus Gem, compared with single Gem treatment. In Western blot analysis, tranilast treatment decreased RRM1 expression at protein level with dose-dependency in KP4 cells. Proteasome inhibitor MG132 disturbed the reduction of RRM1 expression in tranilast treated KP4 cells, indicating protein degradation by the activated proteasome. Transfection using siRNA against RRM1 increased the sensitivity of KP4 to Gem, suggesting that RRM1 suppression is an important step in increasing Gem efficacy. Finally, we demonstrated that tranilast reduced RRM1 protein and increased Gem efficacy in 4 other pancreatic cell lines. In a future, a novel chemotherapeutic strategy by Gem along with tranilast might improve Gem efficacy against pancreatic cancer. less...

Enhancing antitumor activity and minimizing treatment side effects are important issues in cancer therapy. One method to deal with these issues is the utilization of a drug delivery system (DDS). In this study, we developed a novel drug administration pump, a mechanically controlled DDS (M-DDS). The antitumor activity of 5-fluorouracil (5-FU) (15 or 30 mg/kg/day) was evaluated in comparison with systemic intraperitoneal (i.p.) administration for 7 days in a rat model of human pancreatic cancer. The M-DDS was superior to i.p. administration in enhancing antitumor activity and also prolonging median survival from 69 to 85 days at the lower drug dose (15 mg/kg/day). In addition, toxicities in liver, kidney and spleen were found in animals receiving i.p. administration, whereas rats receiving M-DDS treatment did not show these toxicities. The concentration of 5-FU in tumors 1 day after the completion of treatment was considerably higher in rats receiving M-DDS treatment. These results suggest that this novel M-DDS may be a powerful tool for the treatment of pancreatic cancer in combination with conventional chemotherapeutic drugs, offering strong antitumor activity with fewer toxicities. This novel M-DDS, consisting of a control circuit and drug reservoir/pump unit, may be a useful tool for the treatment not only of pancreatic cancer but also of various other accessible cancers for which there is no effective treatment, such as bile-duct and brain tumors. less...

ABSTRACT: The spine is the most common site for bone metastases. Radiation therapy is a common treatment for palliation of pain and for prevention or treatment of spinal cord compression. Helical tomotherapy (HT), a new image-guided intensity modulated radiotherapy (IMRT), delivers highly conformal dose distributions and provides an impressive ability to spare adjacent organs at risk, thus increasing the local control of spinal column metastases and decreasing the potential risk of critical organs under treatment. However, there are a lot of non-target organs at risk (OARs) occupied by low dose with underestimate in this modern rotational IMRT treatment. Herein, we report a case of a pathologic compression fracture of the T9 vertebra in a 55-year-old patient with cholangiocarcinoma. The patient underwent HT at a dose of 30 Gy/10 fractions delivered to T8-T10 for symptom relief. Two weeks after the radiotherapy had been completed, the first course of chemotherapy comprising gemcitabine, fluorouracil, and leucovorin was administered. After two weeks of chemotherapy, however, the patient developed progressive dyspnea. A computed tomography scan of the chest revealed an interstitial pattern with traction bronchiectasis, diffuse ground-glass opacities, and cystic change with fibrosis. Acute radiation pneumonitis was diagnosed. Oncologists should be alert to the potential risk of radiation toxicities caused by low dose off-targets and abscopal effects even with highly conformal radiotherapy. less...

OBJECTIVE: To investigate the effects of antiproliferative drugs (anastrozole, methotrexate, and 5-fluorouracil [5-FU]) on the proliferation of endometriotic cells in vitro and in vivo. DESIGN: Ex vivo study on human endometrial and endometriotic cells in culture; establishment of a murine model using mice implanted with human endometriosis. SETTING: University research center. PATIENT(S): Ten patients with ovarian endometrioma, 10 patients with deep infiltrating endometriosis, and 10 patients without endometriosis. INTERVENTION(S): Stromal and epithelial cells were extracted from endometrial and endometriotic biopsies from patients with endometriosis and from patients without endometriosis. Cells were treated in vitro with anastrozole, methotrexate, progesterone, or 5-FU. Human endometriotic lesions were implanted in nude mice. Mice were treated with 5-FU or phosphate-buffered saline during 4 weeks before sacrifice and extraction of the endometriotic implants. MAIN OUTCOME MEASURE(S): Stromal and epithelial cell proliferation and pathology score of endometriotic implants. RESULT(S): Although anastrozole, methotrexate, and progesterone were ineffective, 5-FU significantly decreased the proliferation of endometriotic cells in vitro and controlled the growth of both cells from ovarian endometrioma and deep infiltrating endometriosis. CONCLUSION(S): Considering common features between endometriotic cells and tumor cells, the use of 5-FU could be an option in the management of severe endometriosis. less...

AIM: In several commonly used regimens, chemotherapy doses are split across different days of the cycle. We aimed to determine the feasibility of growth factor support with once-per-cycle pegfilgrastim in this setting. METHODS: This phase II study in breast cancer patients assessed the utility of a single 6 mg subcutaneous dose of pegfilgrastim administered on day 9 of an intravenous (IV) "split" CMF (cyclophosphamide 600 mg/m(2), methotrexate 40 mg/m(2) and 5-fluorouracil 600 mg/m(2)) chemotherapy regimen administered on days 1 and 8 and repeated every 28 days for 6 cycles. RESULTS: Fifty-eight patients were enrolled, with 49 completing the study. For the primary endpoint, 48 patients (83%) received >or=85% of the relative dose intensity (RDI) of chemotherapy over all 6 cycles (95% confidence interval [CI], 71-91%). Across all chemotherapy cycles, 41 patients (71%) received all scheduled cycles on time and most patients (n=49, 84%) received >or=85% of the planned dose of all chemotherapy agents in all cycles. In total, 295/319 cycles (92%) were delivered on schedule and >or=85% of the planned dose of all chemotherapy agents were administered in 309/319 cycles (97%). Febrile neutropenia was reported in only 2 patients (3%). There were no grade 4 adverse events related to pegfilgrastim. DISCUSSION: Day 9 pegfilgrastim administration was well tolerated and provided effective protection against neutropenia in patients receiving IV CMF on days 1 and 8, allowing chemotherapy to be delivered on time and at the scheduled dose in most patients. less...

BACKGROUND: Although triweekly administration of paclitaxel is approved for gastric cancer in Japan, currently, the drug is often delivered with a weekly schedule because of the equivalent efficacy and lesser toxicity of this dosing schedule as compared with the triweekly administration schedule. Weekly administration of paclitaxel as second-line or first-line chemotherapy for gastric cancer has been reported to yield a response rate of about 20%. Because there has been no report of the efficacy of weekly paclitaxel in the third-line setting, this retrospective study investigated the efficacy and toxicities of weekly paclitaxel used in the third-line setting for the treatment of gastric cancer refractory to all three key drugs, fluorouracil, irinotecan, and cisplatin, used in clinical practice. METHODS: In 85 patients with advanced or recurrent histologically confirmed gastric adenocarcinoma who had failed to respond to prior chemotherapy regimens containing fluorouracil, irinotecan, and cisplatin, paclitaxel (80 mg/m(2)) was administered weekly, three times, for 3 weeks out of 4. RESULTS: The median number of courses was 3 (range, 1-38). The overall response rate was 23.2% (19/82) in the patients with measurable lesions, and ascites disappeared in 15 of 48 patients (31.3%). Progression-free survival was 105 days and the median survival time was 201 days from the initiation of paclitaxel administration. Grade 3 or 4 leukopenia, neutropenia, anemia, and thrombocytopenia were observed in 25 (29%), 25 (29%), 37 (44%), and 3 (4%) patients. Other, nonhematological, toxicities were nausea, vomiting, anorexia, sensory neuropathy, fatigue, and febrile neutropenia. CONCLUSION: Weekly paclitaxel administration shows activity against advanced gastric cancer also in the third-line setting. less...

PURPOSE: Prior trials have shown that surgery followed by hepatic artery infusion (HAI) of floxuridine (FUDR) alternating with systemic fluorouracil improves survival rates. Oxaliplatin combined with capecitabine has demonstrated activity in advanced colorectal cancer. Based on this observation a trial was conducted to assess the potential benefit of systemic oxaliplatin and capecitabine alternating with HAI of FUDR. The primary end point was 2-year survival. PATIENTS AND METHODS: Patients with liver-only metastases from colorectal cancer amenable to resection or cryoablation were eligible. HAI and systemic therapy was initiated after metastasectomy. Alternating courses of HAI consisted of 0.2 mg/m(2)/d FUDR and dexamethasone, day 1 through 14 weeks 1 and 2. Systemic therapy included oxaliplatin 130 mg/m(2) day 1 with capecitabine at 1,000 mg/m(2) twice daily, days 1 through 14, weeks 4 and 5. Two additional 3-week courses of systemic therapy were given. Capecitabine was reduced to 850 mg/m(2) twice daily after interim review of toxicity. RESULTS: Fifty-five of 76 eligible patients were able to initiate protocol-directed therapy and completed median of six cycles (range, one to six). Three postoperative or treatment-related deaths were reported. Overall, 88% of evaluable patients were alive at 2 years. With a median follow-up of 4.8 years, a total of 30 patients have had disease recurrence, 11 involving the liver. Median disease-free survival was 32.7 months. CONCLUSION: Alternating HAI of FUDR and systemic capecitabine and oxaliplatin met the prespecified end point of higher than 85% survival at 2 years and was clinically tolerable. However, the merits of this approach need to be established with a phase III trial. less...