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1.
Recent advances in molecular biology have permitted significant progress toward the treatment of malignant brain tumors using gene transduction methods. Adenovirus vectors have recently been shown to transduce genes successfully into brain tumor cells both in vitro and in vivo. We have investigated the feasibility of gene transduction for brain tumors using adenovirus vectors. To evaluate in vitro transduction rate by adenovirus vectors, rat 9L gliosarcoma cells or human glioblastoma cells were infected with recombinant replication-deficient adenovirus vectors containing the E. coli beta-galactosidase gene (Adex-CALacZ) and stained with X-Gal. We observed a multiplicity of infection (MOI)-dependent rate. Approximately 100% transgene expression was achieved at a MOI of 5 after seven days of incubation. To evaluate transgene expression in a rat brain tumor model, AdexCALacZ was stereotactically injected into established rat 9L brain tumors. Intratumoral injection of AdexCALacZ resulted in high transgene expression in tumor cells. Although injection of AdexCALacZ in the normal basal ganglia resulted in broad and diffuse transduction into endogenous neural cells, direct intratumoral injection resulted in transduction that was relatively restricted to the tumor cells as well as some neighboring normal cells. Transduction rates were relatively elevated at the margin of the tumor. Our results suggest that adenovirus vectors might be a feasible method to transfer therapeutic genes into malignant brain tumors.  相似文献   

2.
The effects of gastrectomy on the pharmacokinetics of UFT, a combined oral preparation of 1-(2-tetrahydrofuryl)-5-fluorouracil (tegafur) and uracil at a molar ratio of 1:4, were examined in 26 patients with macroscopic Stage I gastric cancer. In all, 200 mg UFT (in terms of tegafur) was given to 17 patients who underwent partial gastrectomy (9 cases of Billroth I reconstruction, 8 cases of Billroth II reconstruction) and to 9 patients who underwent total gastrectomy with modified Roux-en-Y reconstruction. Before the operation, the area under the curve (AUC) for tegafur, uracil, and 5-fluorouracil (5-FU) was 79.28 +/- 26.88, 4.41 +/- 1.78, and 0.51 +/- 0.20 micrograms h ml-1, respectively. Partial (Billroth I and II) and total gastrectomy did not alter the AUC of tegafur, and partial gastrectomy using the Billroth I and II methods decreased the AUCs of uracil and 5-FU during the first 2 weeks postoperation. However, plasma levels of uracil and 5-FU reverted to preoperative values at 3 months postsurgery. Our findings show that when UFT is prescribed for patients treated in the early postoperative period following partial gastrectomy for cancer, dose increases and the timing of administration should be given close attention.  相似文献   

3.
Amplification or overexpression of HER-2/neu in human lung cancer has been correlated with poor prognosis and chemoresistance. We have previously reported that the adenovirus type 5 early region 1A (E1A) gene product can suppress HER-2/neu-mediated transformation phenotypes through inhibition of HER-2/neu expression. To find an efficient way to treat HER-2/neu-overexpressing lung cancer with E1A, a replication-deficient adenovirus containing the E1A gene, Ad.E1A(+), was used to transduce E1A into HER-2/neu-overexpressing and low expressing human lung cancer cell lines. Tumour cell growth in vitro and colony formation in soft agarose were greatly inhibited by Ad.E1A(+) transduction in HER-2/neu-overexpressing lung cancer cell lines. In HER-2/neu low expressing cell lines, E1A could not inhibit cell growth in vitro but could reduce the colony formation ability in soft agarose, indicating different effects of E1A in these two types of cancer cells. To test the therapeutic efficacy of E1A to lung cancer by systemic delivery in vivo, tumor-bearing mice were established by intratracheal injection of lung cancer cells and treated by i.v. tail injections of Ad.E1A(+). As a result, Ad.E1A(+) suppressed HER-2/neu overexpression and inhibited intratracheal lung cancer growth. However, no significant tumor suppression effect of Ad.E1A(+) was observed in mice bearing HER-2/neu low expressing cell line when the same therapeutic procedure was followed. Thus, we conclude that systemic delivery of Ad.E1A(+) can efficiently achieve therapeutic effect in HER-2/neu-overexpressing lung cancer in vivo.  相似文献   

4.
In 1993 eighteen Japanese patients with cancer and herpes zoster, a viral disease, died from interactions of the new oral antiviral drug, sorivudine (SRV: 1-beta-D-arabinofuranosyl-(E)-5-(2-bromovinyl)uracil), with oral anticancer prodrugs of 5-fluorouracil (5-FU) within 40 d after SRV was approved by the Japanese government and began to be used clinically. Before the death, most of these patients had severe symptoms of toxicity, including diarrhea with bloody flux and marked decreases in white blood cell and platelet counts. All of these patients received SRV daily for several days while being administered long-term anticancer chemotherapy with one of the oral 5-FU prodrugs. There was no acute toxic symptom in patients who received SRV alone or SRV and the other types of anticancer drugs. A toxicokinetic study was carried out using rats to investigate the mechanism of the acute death in the patients caused by drug interactions between SRV and 5-FU prodrugs. Rats were orally coadministered SRV with tegafur (FT: 1-(2-tetrahydrofuryl)-5-fluorouracil), a 5-FU prodrug that most of the patients were considered to receive before the death. All the rats receiving SRV and FT once daily showed extremely elevated levels of 5-FU in the plasma and tissues, including bone marrow and small intestines, and died within 10 d, while the animals given the same repeated dose of SRV or FT alone were still alive over 20 d without any appreciable toxic symptom. Before their death, there were a marked damage of bone marrow, a marked atrophy of intestinal membrane mucosa, marked decreases in white blood cells and platelets, diarrhea with bloody flux, and severe anorexia as reported for the patients. Data obtained by in vivo and in vitro studies indicated that (E)-5-(2-bromovinyl)uracil (BVU), generated from SRV by the gut flora and absorbed through the intestinal membrane, was reduced in the presence of NADPH to a reactive form by hepatic dihydropyrimidine dehydrogenase (DPD), a key enzyme regulating the tissue 5-FU levels from FT, bound covalently to DPD as a suicide inhibitor, and markedly retarded the catabolism of 5-FU. An irreversible inactivation by BVU of rat and human DPDs, expressed in E. coli for the latter, was observed in the presence of NADPH with their purified preparations in a manner reciprocal to radiolabelling of the enzyme proteins with [14C]BVU. SRV showed no inhibitory effect on the rat and human DPDs in the presence of NADPH.  相似文献   

5.
Continuous intravenous infusion (c.v.i.) of 5-fluorouracil (5-FU) plus daily low-dose cisplatin (CDDP) was evaluated in 45 patients with advanced and recurrent unresected colorectal, lung, gastric and pancreatic adenocarcinoma. 5-FU was given at a dose of 320 mg/m2/day, c.v.i. for 4 weeks, and CDDP between 3.5 to 7 mg/m2/day, infused for one hour five times a week for 4 weeks. Patients received 1 to 3 cycles of treatment (average 1.5 cycle). Pancreatic cancer cases needed longer treatment periods (2.25 cycles). The response rate of colorectal cancer cases was 57.7% (15/26), pancreas cancer 40%, gastric cancer 62.5%, and lung cancer 66.7%. The overall response rate was 57.8%. No severe side effects occurred in any of these cases. These data indicate that this combination 5-FU + daily low-dose CDDP chemotherapy is effective in the treatment of advanced gastrointestinal and lung adenocarcinoma.  相似文献   

6.
The development of vectors that are capable of efficient gene delivery is crucial to the success of gene therapy. We have developed both recombinant viral and nonviral vectors with the goal of correcting genetic abnormalities in cancer cells that are responsible for malignant transformation. Infection of cancer cells by recombinant adenovirus (Adv) indicates that the level of transduction is variable and dependent on the virus-to-cell ratio. Infection of cells with Adv/p53 resulted in levels of tumor suppressor p53 gene expression that could mediate tumor cell growth suppression and apoptosis, both in vitro and in vivo. The treatment of cancer cells with cisplatin prior to Adv transduction resulted in a higher level of therapeutic gene expression. Epidermal growth factor (EGF)/DNA complexes targeted to cancer cells overexpressing the EGF receptor resulted in efficient transduction of several lung cancer cell lines in vitro. As a result, these vectors provide improved methods with which to treat cancer in the clinical setting with gene therapy.  相似文献   

7.
To assess the efficacy of an in vivo adenoviral-mediated cytotoxic gene therapy, human melanomas were established in nude mice and transduced with herpes simplex virus-thymidine kinase (tk) followed by treatment with ganciclovir (GCV). In initial experiments, adenovirus (adv) containing the beta-galactosidase reporter gene was employed to determine melanoma cell infectivity in vitro. In comparison to murine melanoma cell lines B16 and K1735-M2, human A375-SM cells exhibited up to a 10-fold greater susceptibility to adenoviral transduction, similar to the degree of infectivity found for human epidermal HaCaT cells. In addition, human A375-SM melanoma cells exhibited a greater sensitivity in vitro to the cytotoxic effects of transduction with tk-adv and treatment with GCV, which was mediated by a strong bystander effect. In vivo, intratumoral injection of relatively large human melanomas (160 mm3) with 1.2 X 109 pfu of tk-adv, followed by intraperitoneal GCV treatment (60 mg/kg twice daily) over 4 days, typically resulted in a 50% reduction in melanoma growth rate compared to mock or untreated controls. Moreover, histometrical analysis employing a rigorous computerized imaging system revealed that the residual viable tumor area in the tk-adv/GCV-treated group was only one-fifth that of solvent controls. These data show that adv is a highly efficient in vivo gene delivery system to treat experimental human melanomas. In comparison to a previous murine melanoma study, human melanomas appeared to exhibit a greater sensitivity to this cytotoxic treatment in vivo, which may hold significant promise for development of effective gene therapy modalities to treat melanoma in humans.  相似文献   

8.
Two obstacles limiting the efficacy of nearly all cancer gene therapy trials are low gene transduction efficiencies and the lack of tumor specificity. Recently, a replication-competent, E1B-attenuated adenovirus (ONYX-015) was developed that could overcome these limitations, because it was capable of efficiently and selectively destroying tumor cells lacking functional p53. In an attempt to improve both the efficacy and safety of this approach, we constructed a similar adenovirus (FGR) containing a cytosine deaminase (CD)/herpes simplex virus type-1 thymidine kinase (HSV-1 TK) fusion gene, thereby allowing for the utilization of double-suicide gene therapy, which has previously been demonstrated to produce significant antitumor effects and potentiate the therapeutic effects of radiation. The FGR virus exhibited the same tumor cell specificity and replication kinetics as the ONYX-015 virus in vitro. Importantly, both the CD/5-FC and HSV-1 TK/GCV suicide gene systems markedly enhanced the tumor cell-specific cytopathic effect of the virus, and, as expected, sensitized tumor cells to radiation. By contrast, neither the FGR virus nor either suicide gene system showed significant toxicity to normal human cells. Both suicide gene systems could be used to suppress viral replication effectively, thereby providing a means to control viral spread. The results support the thesis that the three-pronged approach of viral therapy, suicide gene therapy, and radiotherapy may represent a powerful and safe means of selectively destroying tumor cells in vivo.  相似文献   

9.
We evaluated the therapeutic efficacy of intraarterial infusion chemotherapy in advanced gastric cancer, its side effect and patient prognosis, in comparison with systemic infusion. Of 125 cases of advanced gastric cancer, 41 cases received intraarterial chemotherapy (A group) and the rest were given systemic infusion (S group). Protocols of chemotherapy were 5-FU + MTX in 49 cases, 5-FU + cisplatin in 62, and 5-FU + MMC in 14. Location of the disease was the peritoneum in 69 cases, nodes in 59, liver in 38, and other sites, 33. The response rate of A group was significantly higher than that of S group, at 31% and 13% respectively. Although 41% of cases showed side effects (> or = grade 2), there was no significant difference between the 2 groups. The median survival period and 1-year survival rate were 8.4 months and 35%, respectively, and there was no significant difference between the 2 groups. In cases with liver metastasis, the prognosis of A group was better than that of S group. The results suggest that intra-arterial infusion chemotherapy is an effective treatment for liver metastasis from gastric cancer.  相似文献   

10.
The E. coli cytosine deaminase (CD) provides a negative selection system for suicide gene therapy as CD transfectants are eliminated following 5-fluorocytosine (5FC) treatment. Here we report a positive selection system for the CD gene using 5-fluorouracil (5FU) and cytosine in selection medium to screen for CD-positive transfectants. It is based on the relief of 5FU toxicity by uracil which is converted from cytosine via CD catalysis, as uracil competes with the toxic 5FU in subsequent pyrimidine metabolism. Hence, a retroviral vector containing the CD gene may provide both positive and negative selections after gene transfer. The CD transfectants selected with the positive selection system showed susceptibility to 5FC in subsequent negative selection in vitro and in vivo. Therefore, this dual selection system is useful not only for combination therapy with transgene and CD gene, but can also act to eliminate selectively transduced cells after the transgene has furnished its effects or upon undesired conditions if 5FC is applied for negative selection in vivo.  相似文献   

11.
A human colon cancer cell line, HCT-15, was found to proliferate in human sera. Sera of cancer patients undergoing continuous intravenous administration of 5-fluorouracil (5-FU) were tested for the antitumor effect by counting HCT-15 cells stained with Giemsa solution. 5-FU concentrations in those sera were not correlated with the antitumor effects. After HCT-15 cells were incubated in sera of cancer patients or healthy volunteers for 24 hours followed by removal of those sera, those cells were incubated in a culture medium containing 500 or 1000 ng/ml of 5-FU for 48 hours. It was shown that preincubation of HCT-15 cells with sera of cancer patients but not sera of healthy volunteers decreased the sensitivity of HCT-15 cells to 5-FU. These results suggest that there may be some factors in the serum of a cancer patient, which affect the antitumor effect of 5-FU.  相似文献   

12.
The first-pass intestinal metabolism of 5-fluorouracil (5-FU) was investigated by single-pass perfusion of the rat small intestine. At the low concentration of 0.06 mg/ml, the fraction of 5-FU absorbed into (i.e., appeared in) the mesenteric venous blood (Fa,b) was about 50% smaller than the fraction absorbed (disappeared) from the intestinal lumen (Fa), indicating the first-pass extraction of 5-FU in the intestinal mucosa. By addition of uracil (6 mg/ml), the Fa of 5-FU was reduced presumably by competition for the pyrimidine carrier at the process of intestinal uptake (entry into the mucosa). The Fa,b was also reduced, but to a lesser extent, resulting in insignificant first-pass extraction. These results suggest that the extraction of 5-FU in the absence of uracil is caused by metabolism and that uracil is a competitor for this pathway. When 5-FU concentration was raised from 0.06 to 0.6 mg/ml in the absence of uracil, the Fa was reduced by about 50%, consistent with the suggestion of the involvement of saturable uptake by the pyrimidine carrier, and thereafter remained unchanged at 6 mg/ml. However, since Fa,b was also reduced by a similar extent, the intestinal availability (FI=Fa,b/Fa) was unchanged at about 0.5, indicating that the intestinal first-pass extraction of 5-FU is independent of concentration with the extraction ratio (difference between unity and FI) of about 0.5 over the wide range of concentration from 0.06 to 6 mg/ml. Thus, the present study demonstrates that the significant first-pass metabolic extraction of 5-FU occurs in the mucosa of the small intestine, supporting our previous suggestion that 5-FU undergoes first-pass metabolism not only in the liver but also in the small intestine after oral administration. Considering that the oral bioavailability of 5-FU in the human (28%) is reportedly comparable with that in the rat (28%), it is likely that intestinal first-pass metabolism may be significant also in the human. Intestinal first-pass metabolism should be taken into account to explore more efficient and controlled oral 5-FU therapy.  相似文献   

13.
14.
Adenovirus infection of CD34+ hematopoietic stem/progenitor cells is dependent on the multiplicity of infection (MOI), time of incubation, the volume in which the co-incubation occurs and the presence or absence of growth factors. Studies revealed that a brief co-incubation (1-8 hours), resulted in low levels of transgene expression, suggesting that adenovirus infection of CD34+ cells occurs slowly, and optimal transduction requires a 24 hour exposure to adenovirus. Infection by Ad/beta-gal or Ad/p53 at a MOI of 500:1 provided a high transduction efficiency but inhibited hematopoietic function. However, treatment at a MOI of 50-100 resulted in efficient transduction (10.7-15.7% positive) without detectable toxicity. Secondary proof of adenovirus transgene expression was demonstrated by detection of mRNA for p53 in Ad/p53 infected stem cells. We conclude that a 24 hour exposure to recombinant adenovirus encoding p53 or beta-gal, at a MOI of 50-100 is optimal for in vitro gene transfer to BM cells and has no significant effect on hematopoietic function. Adenovirus-mediated transduction of BM cells can also be modulated by growth factors (IL-3, GM-CSF and G-CSF) with improved gene delivery and maintenance of hematopoietic function. In summary, adenovirus vectors can be used to transiently transduce stem cells, and conditions have been defined to maximize expression and limit inhibitory effects on CD34+ cells. These data support continued investigation of this vector for local cytokine delivery and purging of stem cell products.  相似文献   

15.
Tumor cells that express a fusion gene comprised of Escherichia coli cytosine deaminase (CD) and herpes simplex virus type 1 thymidine kinase (TK) sequences exhibit activation of and subsequent killing by the normally innocuous prodrugs 5-fluorocytosine and ganciclovir (Rogulski et al., Hum. Gene Ther., 8: 73-85, 1997). To target localized expression of this therapeutic gene, we have constructed a recombinant adenovirus containing the CD-TK fusion gene under the control of a human inducible heat shock protein 70 promotional sequence. Strong expression of the fusion gene product was induced by heating at 41 degrees C for 1 h. Expression levels obtained were dependent on the multiplicity of infection used and the incubation time after heat shock. Heat-induced expression of the CD-TK protein significantly reduced the survival of PC-3 cells in the presence of both 5-fluorocytosine and ganciclovir. These studies represent a novel form of gene therapy for the transduction and regulation of a double suicide gene in tumor cells and may provide a unique application for hyperthermia in cancer therapy.  相似文献   

16.
The modulation of 5-fluorouracil (5-FU) with folinic acid (leucovorin, LV) is more efficacious than 5-FU alone in the treatment of metastatic colorectal cancer, and the combination of 5-FU with cisplatin is currently one of the most active regimens in advanced gastric cancer. A phase II study was therefore conducted to test the efficacy and toxicity of the combination of 5-FU, LV and cisplatin (FLP) in metastatic gastric cancer. 28 patients entered the study. Metastatic sites were observed in the liver (in 21 patients), the peritoneum (in 8), the lymph nodes (in 7) or the bones (in 1) and a local recurrence was noted in 4 cases. The performance status (using World Health Organisation criteria) was 0 for 13 patients and 1 or 2 for the others. Cycles of treatment were administered every 28 days and consisted of LV 200 mg/m2/day for 5 days followed by 5-FU 400 mg/m2/day for 5 days with cisplatin 100 mg/m2 on day 2. The response rate for the 27 evaluable patients was 51.8% (95% confidence interval (CI), 33-70.6%). There were four complete responses (14.8%) and 10 partial responses (37%). Median survival was 11 months and 4 patients were alive at 2 years. Both response rate and survival were better for patients with a good performance status. The overall toxicity was very low, except for 1 patient who died of dehydration and cardiac failure. In conclusion, the FLP protocol was effective and well tolerated in patients with metastatic gastric cancer.  相似文献   

17.
The hypoxanthine-xanthine-guanine phosphoribosyl transferase (HXGPRT) gene of the protozoan parasite Toxoplasma gondii encodes a safe, practical genetic marker suitable for both positive and negative selection. Taking advantage of the ability to control homologous versus nonhomologous recombination in haploid T. gondii tachyzoites by manipulating the length of homologous DNA sequence, we have explored the possibility of 'hit-and-run' mutagenesis to introduce gene knock-outs (or allelic replacements) at loci for which no known selection or screen is available. Using the uracil phosphoribosyl transferase (UPRT) locus as a target, a genomic clone containing approximately 8 kb encompassing the UPRT gene (but lacking essential coding sequence) was fused to a cDNA-derived HXGPRT 'minigene', which lacks sufficient contiguous genomic sequence for homologous recombination. After transfection of circular plasmid DNA, positive selection for HXGPRT activity identified stable transformants, > 30% of which were found to have integrated at the UPRT locus as 'pseudodiploids' (produced by single-site homologous recombination between the circular plasmid and genomic DNA). Upon removal of mycophenolic acid, resolution of pseudodiploids by spontaneous intrachromosomal homologous recombination was selected using 6-thioxanthine, yielding a 1:1 ratio of UPRT knock-out parasites to wild-type revertants, at frequencies of approximately 10(-6) per parasite doubling. Applications of 'hit-and-run' technology relative to other gene targeting strategies are discussed.  相似文献   

18.
Recombinant adenovirus (Adv)-mediated gene transduction is a powerful technology for cancer gene therapy. In this article, we report the generation of a fiber-mutant Adv vector, using the Adv genomic DNA-terminal protein complex (DNA-TPC) cotransfection method. First, a fiber-mutant construct in a plasmid carrying the right-side two-thirds of the human adenovirus type 5 (Ad5) genome (pTR) was cotransfected with Ad5 DNA-TPC, yielding the recombinant Adv with the desired fiber mutation. The DNA-TPC from the mutant Adv was then utilized to produce a second-step recombinant Adv with an expression cassette in the place of E1. By this procedure, we generated a fiber mutant, F/K20, that has a linker and a stretch of 20 lysine residues added at the C terminus of the fiber. By using Adv carrying a reporter lacZ gene (AxCAZ2) with either F/K20 or wild-type fiber (F/wt), we examined the transduction efficiency of F/K20-Adv. No significant difference in the transduction efficiency between F/K20 and F/wt-Adv was observed for a human fibroblast line, WI-38, or various tumor cell lines, including melanoma, prostate, esophageal, and pancreatic cancer lines. In clear contrast, F/K20-Adv showed a remarkably enhanced efficiency in genetic transduction of human glioma cells. In all four human glioma lines tested, the multiplicities of infection (MOIs) for transduction of 50% of the population (ED50) were decreased with F/K20-Adv compared with F/wt-Adv: 7-fold for T98G, 14-fold for U251, 9-fold for U373, and 42-fold for U87 cells. Therefore, we attempted to apply F/K20-Adv for gene therapy of malignant glioma. Glioma cells infected with F/K20-Adv carrying genes for interleukin 2 or interleukin 12 produced a high level of each cytokine at a much lower MOI than did cells infected with F/wt-Adv. Infection with F/K20-Adv carrying the wild-type p53 tumor suppressor gene resulted in an enhanced level of p53 protein expression and an increased incidence of F/K20-Adv in transduction efficiency for malignant glioma, providing promising tools for gene therapy.  相似文献   

19.
In this report, a replication-defective herpes simplex virus type 1 (HSV-1) vector has been employed to deliver the Escherichia coli LacZ and HSV thymidine kinase (HSVtk) genes to six human ovarian carcinoma cell lines and the efficacy of gene transfer compared to that of adenoviral vectors in vitro. The transduction efficiency of the LacZ-containing virus TOZ.1 was evaluated qualitatively and quantitatively following infection of the different ovarian cancer cell lines. The therapeutic ability of the HSV-T3 vector, which contains the HSVtk gene, was additionally investigated in comparison to the AdCMVHSVTK. Our results show that HSV-1-mediated gene transfer is quantitatively superior to adenoviral vector in five of the six ovarian cancer cell lines at a 100-fold lower dose in vitro. Our preliminary studies suggest that HSV-1 may be a promising alternative vector for ovarian cancer gene therapy.  相似文献   

20.
Clinical usefulness of a new combination FTM therapy consisting of 5-FU, Pirarubicin (THP) and MMC for the treatment of advanced gastric cancers was investigated. 5-FU, THP or MMC was administered at a dose of 600 mg/m2 on day 1, 8, 22 and 29, 30 mg/m2 on days 1 and 22, and 10 mg/m2 on day one only of each course, respectively. Eighteen patients with inoperable advanced gastric cancer were treated with FTM. All drugs were investigated by intravenously by one shot. The tumor response rate was 50% [9 of 18 showed PR]. The survival rate was higher in responders than in nonresponders (18.1% vs 11.1%) (p < 0.05). Side effects in the gastrointestinal tract were minimal. Cardiotoxicity and nephrotoxicity were not detected, but myelosuppression was prominent in most cases. G-CSF was given in sixteen patients (88%), and platelet transfusion was performed in two patients (11%). New combination FTM therapy is an effective treatment regimen even for advanced inoperable gastric cancer.  相似文献   

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