Development of murine leukemia virus-based retroviral vectors with a minimum possibility of cis-activation

The possibility of insertional mutagenesis in retroviral gene therapy can be reduced by using a vector lacking the enhancer sequence present in the U3 of the long-terminal repeats. However, such vectors suffer from many pitfalls. We attempted to improve a murine leukemia virus-based retroviral vector containing the enhancer-free U3, first by making it easier to construct a producer line and then by introducing the cellular RPL10 promoter as an internal promoter. The reverse orientation of the expression cassette of the transgene was found to give higher transducing titer and higher-level gene expression. The deletion analysis revealed that the 54-bp-long sequence of U3 (34 and 20 bp present at 5' and 3' extreme ends, respectively) was sufficient for the functions of retroviral vectors. The data from the in vitro cell culture assay indicated that the final construct, ROK, containing all these features, had little cis-activation activity, even if it was placed right upstream from the RNA start site of the neighboring gene. Our data suggested that the newly developed vector might provide increased safety, while still producing high viral titer from a stable producer line and high-level gene expression in various target cells including human CD34(+) stem cells.

Solution-processed flexible ZnO transparent thin-film transistors with a polymer gate dielectric fabricated by microwave heating

We report the development of solution-processed zinc oxide (ZnO) transparent thin-film transistors (TFTs) with a poly(2-hydroxyethyl methacrylate) (PHEMA) gate dielectric on a plastic substrate. The ZnO nanorod film active layer, prepared by microwave heating, showed a highly uniform and densely packed array of large crystal size (58 nm) in the [002] direction of ZnO nanorods on the plasma-treated PHEMA. The flexible ZnO TFTs with the plasma-treated PHEMA gate dielectric exhibited an electron mobility of 1.1 cm(2) V(-1) s(-1), which was higher by a factor of approximately 8.5 than that of ZnO TFTs based on the bare PHEMA gate dielectric.

Photopatternable source/drain electrodes using multiwalled carbon nanotube/polymer nanocomposites for organic field-effect transistors

We fabricated photopatternable and conductive polymer/multiwalled carbon nanotube (MWNT) composites by dispersing MWNTs with poly(4-styrenesulfonic acid) (PSS) and poly(acrylic acid) (PAA) in water. PAA enables photo-cross-linking in the composite by adding ammonium dichromate, and PSS assists the dispersion of MWNTs in the composites, leading to higher conductivity. Composite films of PAA/PSS-MWNTs were characterized by conductivities of 1.4-210 S/cm and a work function of 4.46 eV, which could be increased to 4.76 eV during UV photo-cross-linking. By using PAA/PSS-MWNT composites as source/drain electrodes, 6,13-bis(triisopropylsilylethynyl)pentacene field-effect transistors (FET) exhibited a field-effect mobility of 0.101 +/- 0.034 cm(2)/(V s), which is 9 times higher than that of FETs fabricated with gold as source/drain electrodes (0.012 +/- 0.003 cm(2)/(V s)).

Clinical significances of preoperative serum IL-6 and CRP level in operable gastric cancer

e15591

Background: The interleukin (IL)-6 pathway is one of the mechanisms liking inflammation and angiogenesis to malignancy. As the C-reactive protein (CRP) is representative marker of inflammation, recently CRP has been reported to be associated with processing of disease in many cancers. This study aims to determine the preoperative serum levels of IL-6 and CRP in gastric carcinoma, and correlate them with disease status and prognosis. Methods: A total of 115 patients receiving gastrectomy entered this study. Serum level of IL-6 was measured by using Enzyme-Linked Immuno-Sorbent Assay (ELISA) and CRP was measured by using immunoturbidimetry. Histological findings were included depth of tumor invasion, lymph node (LN) metastasis, and TNM stage (AJCC Stage Groupings The staging systems; Primary tumor, regional LN, metastasis). Results: The more cancer invasion and stage are high, the more preoperative serum IL-6 levels are high. IL-6 level was correlated with depth of invasion (P=0.006) and TNM stage (P<0.001). Preoperative CRP level also correlated with depth of invasion (P<0.001), TNM stage (P=0.001), and presence of peritoneal seeding metastasis (positive 0.66 ± 0.69 mg/dL, negative 0.20 ± 0.29 mg/dL; P<0.001). When we put cutoff value of IL-6 level (6.77 pg/dL) by ROC curve, although patients’ survival did not reach the median value, it shows significant difference in time to progression (TTP; P<0.001) and overall survival (OS; P<0.010). But, CRP did not show significance to patients’ TTP and OS. Conclusions: Preoperative serum IL-6 and CRP levels might be markers of tumor invasion and TNM stage. Preoperative high IL- 6 level was a poor prognostic factor of disease recurrence and overall survival in patients with gastric cancers.

No significant financial relationships to disclose.

Clinical implication of ERCC1 overexpression in advanced biliary tract adenocarcinoma patients treated with platinum-based palliative chemotherapy

e22018

Background: Several clinical studies have shown that Excision repair cross-complementation group1 (ERCC1) overexpression is associated with resistance to platinum-based chemotherapy and poor prognoses in several tumors. However these studies have never been tried for biliary tract cancer. The aim of this study was to evaluate the association between ERCC1 expression and treatment outcomes in advanced biliary tract adenocarcinoma patients treated with platinum-based palliative chemotherapy. Methods: We analyzed 45 patients with histologically confirmed adenocarcinoma of biliary tract at 5 institutions between January 2002 and March 2008. ERCC1 expression was assessed by immunohistochemistry from biopsy specimens. Results: ERCC1 expression was positive in 17 of 45 specimens (37.8%). 26 (57.8%) of 45 patients showed clinical benefits(including complete response, partial response and stable disease). Among 26 patients who obtained clinical benefits, seven (27%) were positive for ERCC1 expression and ninety (73%) were negative (p=0.079). With a median follow-up of 6.6 months (range, 0.9–39.4 months), median Progression free survival (PFS) and Overall survival (OS) were 4.4 months (95% CI, 3.2–5.6 months) and 8.5 months (95% CI, 6.1–10.9 months), respectively, for the total study population. On univariate analysis, PFS was 2.3 months for patients with ERCC1 positive tumor and 5.3 months for those with ERCC1 negative tumor (P = 0.053). However OS was significantly longer in the ERCC1-negative group than in the ERCC1-positive group (10.0 vs 4.4 months, respectively; P = 0.001). Other factors affecting the prolongation of OS were objective response rate (P = 0.016) and clinical benefits (P = 0.001). A Cox proportional hazard model showed that negative ERCC1 expression (hazard ratio 0.405, 95% CI, 0.200–0.820; P = 0.012) and clinical benefit (hazard ratio 0.183, 95% CI 0.080–0.420; P = 0.001) were significant independent prognostic factors for the prolongation of survival. Conclusions: These results suggest that advanced biliary tract adenocarcinoma patients with ERCC1-negative tumors show a survival benefit from palliative chemotherapy with a platinum- containing regimen.

No significant financial relationships to disclose.

Postoperative LV5FU2 combination chemotherapy in patients with curative resected advanced gastric cancer

e15660

Background: To illuminate the effect and toxicity of fortnightly low-dose leucovorin(LV) and fluorouracil(5FU) bolus plus continuous infusion(LV5FU2) postoperative chemotherapy(adjuvant) in patients with curative resected, advanced gastric cancer. Methods: Total 40 patients were enrolled in this study. All patients received LV 20mg/m2(bolus), 5FU 400mg/m2(bolus), 5FU 600mg/m2(24-hour continuous infusion) on day 1, 2, 15, and 16, every 4 weeks(LV5FU2), total 6 cycles. Results: Postoperative chemotherapy was initiated median 19 days after surgery. Total of 238 cycles were administered and median follow-up was 602 days. The median disease-free survival time was 728 days (95% CI, 411∼1045) and 2-year overall survival was 77%. Relapses were reported in 18 (45%) of the patients : Two of 9 patients relapsed in stage IIIA (22.2%), seven of 12 patients relapsed in stage IIIB (58.3%) and nine of 17 patients relapsed in stage IV (52.9%). They were all distant relapsed. Eight patients died. 7 patients died as a result of cancer progression and 1 patient suicided while receiving palliative chemotheraphy for cancer relapse. The grade 3∼4 toxicity of neutropenia 8.4% and anemia 0.4%, neutropenic fever 0.4% were observed. Conclusions: Postoperative LV5FU2 adjuvant chemotherapy is effective and tolerable for the patients with curative resected, advanced gastric cancer.

No significant financial relationships to disclose.

Combination chemotherapy with irinotecan and cisplatin in elderly patients (≥65 years) with extensive-disease small-cell lung cancer

18135

Background: Combination chemotherapy with irinotecan and cisplatin is one of the standard treatments for patients with small-cell lung cancer (SCLC). In elderly patients, however, its efficacy and toxicity has not been well documented. In this Phase II study, we assessed the efficacy and toxicity of combination chemotherapy with irinotecan and cisplatin and examined whether advanced age compromises it in elderly patients with previously untreated extensive-disease small-cell lung cancer (ED-SCLC). Methods: In this study, 43 previously untreated elderly patients (65 years or older) with ED-SCLC were given combination chemotherapy consisting of irinotecan 60mg/m2 on days 1, 8 and 15 and cisplatin 60mg/m2 on days 1. The treatment was repeated every four weeks until patients completed the maximum six cycles. Results: Patients consisted of 34 men and 9 women, whose median age was 70 years (range 65 - 81 years). A complete response and a partial response were observed in 23.3% (10/43) and 58.1% (25/43), respectively. The overall response rate was 81.4% (95% C.I; 69.7 - 93.0%). The overall median survival was 10.3 months (range 7.8 - 12.7 months). The 1-year and 2- year survival rates were 31.8% and 3.4%, respectively. The median progression-free survival was 8.32 months (range 6.8 - 9.8 months). Major toxicities included neutropenia (grade 3 to 4, 55.9%), leukopenia (grade 3 to 4, 46.5%), infection (grade 3 to 4, 37.3%) and diarrhea (grade 3 to 4, 30.3%). Incidence of febrile neutropenia was significantly higher in patients with ECOG performance status 2 compared with ECOG performance 1 (70.7% vs. 5.2%; p < 0.001). There were two treatment related deaths in patients ECOG performance status 2. Conclusions: Our results indicate that combination chemotherapy with irinotecan and cisplatin is an effective treatment for elderly patients with ED-SCLC. However, physicians should be aware of the mortality and morbidity due to myelosuppression following this treatment in elderly ED-SCLC patients with ECOG performance status 2.

No significant financial relationships to disclose.

Preoperative level of VEGF and IL-6 are associated with lymph node invasion and stage in gastric cancer

4626

Introduction: Angiogenesis plays an important role in growth, progression, and metastasis of tumors, and various cytokines are associated with the spread of cancer cell. In this study, we evaluate the role of VEGF and IL-6 in predicting the spread of gastric cancer. Methods: Preoperative one hundred twenty seven gastric cancer patients and 88 healthy subjects’ specimens were examined. The association of VEGF and IL-6 level with clinical and pathological findings was evaluated Results: Serum VEGF and IL-6 level in gastric cancer patients were higher than those in control (P<0.001, P=0.006, respectively). VEGF and IL-6 level were associated with presence of LN metastasis (P=0.003, P=0.041, respectively). IL-6 level was correlated with stage (P=0.012) and depth of invasion (P=0.018). VEGF level was correlated with invasion of lympho-vascular structure (P=0.021). VEGF and IL-6 level was not related to differentiation, size or CEA level. Conclusions: Serum VEGF and IL-6 levels in gastric cancer patients are higher than those in control. Preoperative VEGF and IL-6 levels could be a predictive marker of tumor invasion and LN metastasis.

No significant financial relationships to disclose.

Cyberknife stereotactic radiosurgery in patients with primary hepatocellular carcinoma

4645

Background: Conventional radiotherapy has historically played a limited role in the primary treatment of hepatocellular carcinoma (HCC). This study evaluated the effect of Cyberknife stereotactic radiosurgery (SRS) with for both for small primary non-resectable HCC, and for advanced HCC with portal vein tumor thrombosis (PVTT). Methods: From March 2004 to March 2005, thirty one patients with HCC were treated Cyberknife SRS was used for 32 lesions in patients with SRS for primary HCC. There was performed in 22 patients (23 lesions) with targeting to the primary HCC was treated (Group A), and in 9 patients with targeting to the PVTT was treated (Group B). The total SRS doses treated were 30–39 Gy (median, 36 Gy) to the 70–85%, 3 fractions and the target volume was of 3.6–57.3 cc (median, 25.2 cc). Results: The median follow up was 10.5 months. A complete response (CR) was achieved in 10 lesions, a partial response (PR) in 13 lesions, stable disease was noted in 6 lesions, and disease progression in 3 lesions. The response rate (CR+PR) was 71.9% (group A: 82.6%, group B: 44.4%). The level of serum alpha-fetoprotein after the treatment was decreased significantly in 17 patients (54.8%) (group A: 54.5%, group B: 55.5%). Complications were observed in 15 patients, among them, greater than grade 3 complication was observed in two patients of group A (gastric ulcer bleeding (1), liver necrosis (1)). Conclusions: These results suggest that Cyberknife SRS could be considered as an effective and safe treatment for primary HCC. For PVTT, Cyberknife SRS as the only curative tool, and produced acceptable local control in this study.

No significant financial relationships to disclose.