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Charles E Welander - One of the best experts on this subject based on the ideXlab platform.

  • an in vitro Thymidine Incorporation Assay for human cancers technical details revisited
    Stem Cells, 1992
    Co-Authors: Koichiro Sugihara, Lee Ann Collins, Howard D Homesley, Charles E Welander
    Abstract:

    : Among the choices of laboratory methods for in vitro testing of human tumor chemosensitivity, a Thymidine Incorporation Assay (TIA) has been described. Advantages of a TIA over a colony-forming Assay include greater probability of tumor growth, requirement for fewer tumor cells, less dependence on an absolute single-cell suspension, shorter time to completion, and the ability to measure up to three logs cell-kill. Specific technical details which are reported in the literature for performing a TIA are incomplete and/or conflicting between one laboratory and another. This paper reports details of methods designed to remove unbound 3[H]-Thymidine from the agarose, standardize background counts, and determine optimal cell-plating densities, labeling time, optimal concentration of 3[H]-Thymidine, and the best day after seeding cultures to add the 3[H]-Thymidine. Care has been taken to compare the end point of drug sensitivity determinations following these methodologic changes, both among serial TIAs as well as with colony-forming Assays.

Ryusuke Muraoka - One of the best experts on this subject based on the ideXlab platform.

  • Improvement of in vitro chemosensitivity Assay for human solid tumors by application of a preculture using collagen matrix.
    Clinical Cancer Research, 1997
    Co-Authors: A Kitaoka, Ryusuke Muraoka, N Tanigawa
    Abstract:

    The use of [3H]Thymidine Incorporation Assay (TIA) to evaluate the drug response of tumor cells has been recognized as a useful chemosensitivity Assay for fresh human tumor specimens. However, its low evaluability has been a disadvantage for clinical application. To overcome this drawback, we have applied a preculture stage prior to the TIA. This preculture requires plating the tumor cell suspension onto a collagen matrix for 24 h. In 29 fresh human tumor specimens, a significant increase in both cell viability (P

  • Potential and limitation of scintillation Assay (TIA) for clinical chemotherapy
    Human Cell, 1995
    Co-Authors: Tanigawa N, A Kitaoka, Takumi Shimomatsuya, Yamakawa M, Ryusuke Muraoka
    Abstract:

    : The clinical significance of the scintillation Assay (Thymidine Incorporation Assay) which we developed was summarized as follows; 1)Thymidine uptake by tumor cells which can be evaluated in each Assay functioned as a significant predictor of prognosis of patients with gastric or colorectal cancer, 2)the tumor cell compartment in this Assay system significantly increased more than did those in other culture systems, 3)evaluable rates were increased to more than 80% by introduction of the preculture system with collagen coated flasks, and 4)it can be considered that chemosensitivity testings may benefit for some types of human tumor, but not for all.

  • clinical significance of p glycoprotein expression and multidrug resistance assessed by in vitro Thymidine Incorporation Assay in patients with gastric carcinoma
    Gan to kagaku ryoho. Cancer & chemotherapy, 1994
    Co-Authors: Hidenori Fujii, Nobuhiko Tanigawa, Ryusuke Muraoka, M Yamakawa, Yasuhiko Masuda, Takumi Shimomatsuya, Yasushi Kato, Toshiharu Aotake, A Kitaoka, Toshiyuki Tanaka
    Abstract:

    : Drug resistance in chemotherapy is a significant problem in the treatment of gastric carcinomas as well as other malignant tumors. Multidrug resistant cells frequently overexpress the 170 kDa P-glycoprotein (P-gp). Twenty-four fresh tumor specimens of gastric carcinoma were assessed by flow cytometric detection of P-gp using monoclonal antibody C219. Eight patients were P-gp positive. Differentiated gastric carcinomas contained significantly higher concentrations of P-gp positive. Incidence of P-gp positive case was high in advanced stage. Sixteen cases received in vitro chemosensitivity test assessed by Thymidine Incorporation Assay (TIA). Seven of 9 multidrug resistant cases by TIA were P-gp positive, and all of 7 non-multidrug resistance were negative. Expression of P-gp and multidrug resistance were closely correlated (p < 0.01). Also, in 89 patients with operable gastric carcinoma, the relationship between multidrug resistance by TIA and their clinicopathologic features as well as their survival lengths were examined. Thirty-one of 89 specimens from gastric carcinoma patients were multidrug resistant by TIA. Patients with multidrug resistant group had a significantly poorer cumulative survival rate than non-multidrug resistant cases (p < 0.01). The multivariated analyses showed that multidrug resistance analyzed is useful indicator for prognosis (p < 0.1). We suggest that multidrug resistance cases or P-gp-positive cases of gastric carcinoma are highly malignant, and these determinations are clinically useful.

  • in vitro chemosensitivity Assay using a double layer agar system human tumor cloning Assay and Thymidine Incorporation Assay
    Gan to kagaku ryoho. Cancer & chemotherapy, 1993
    Co-Authors: Nobuhiko Tanigawa, Talcumi Shimomatsuya, Ryusuke Muraoka, Hidenori Fujii, M Yamakawa, H Saitoh
    Abstract:

    : Human tumor cloning Assay (HTCA) and Thymidine Incorporation Assay (TIA) were both performed using a double-layer-agar system with continuous exposure of cells to standard anticancer drugs. The rate of evaluable Assays was 44% (280 of 638 tumor samples) in HTCA and 48% (216 of 452) in TIA. When the tumor samples were restricted to the gastric and colorectal cancers, it was significantly higher in TIA than HTCA (p < 0.01). HTCA was 95% reliable for predicting in vivo resistance and 52% reliable for in vivo sensitivity, whereas TIA was 88% reliable for in vivo resistance and 44% for in vivo sensitivity. These results seem to suggest that it is unnecessary to select just clonogenic tumor cells among whole tumor cell population in assessing chemosensitivity of human tumors. The current study also indicates that chemotherapy with in vitro sensitive drugs assessed by TIA produced longer survival of the patients with stage III or IV gastric cancer. Most of clinical correlation trials including this study, however, have been performed retrospectively. The prospective study is necessary to determine whether drug selection by in vitro Assays is superior to that by an experienced oncologist. In addition, further studies on pharmacokinetics of anticancer drugs are required to solve some other problems inherent to the current chemosensitivity Assays.

  • in vitro growth ability and chemosensitivity of gastric and colorectal cancer cells assessed with the human tumour clonogenic Assay and the Thymidine Incorporation Assay
    European Journal of Cancer, 1992
    Co-Authors: Nobuhiko Tanigawa, Hideki Morimoto, Naochika Dohmae, Talcumi Shimomatsuya, Kohji Takahashi, Ryusuke Muraoka
    Abstract:

    Abstract A human tumour cloning Assay (HTCA) has been performed on 191 samples of gastric and 152 samples of colorectal cancers, and a Thymidine Incorporation Assay (TIA) on 178 samples of gastric and 109 samples of colorectal cancers. The rate of evaluable Assays was significantly higher in the TIA than in the HTCA (P

H Kodama - One of the best experts on this subject based on the ideXlab platform.

  • in vitro dna synthesis in freshly separated human breast cancer cells assessed by tritiated Thymidine Incorporation Assay relationship to the long term outcome of patients
    British Journal of Surgery, 1999
    Co-Authors: K. Tamura, Takashi Inamoto, K Ohgaki, H Kodama
    Abstract:

    Background: Tumour growth rate has a significant effect on the clinical course of various malignancies. The present study was designed to assess whether in vitro DNA synthesis in freshly separated breast cancer cells is a useful marker in evaluating growth rates and in predicting the clinical outcome of patients. Methods: From 1982 to 1992, DNA synthesis was assessed by [3H]Thymidine Incorporation in 97 samples of primary lesions from 94 patients with breast cancer. The patients were followed for 5–15 years and their outcome was surveyed in January 1998. Results: The level of DNA synthesis did not correlate with the patients' age, clinical stage or expression of oestrogen receptor. However, it correlated significantly with the histological grade. In 89 patients, whose outcome was reported, the survival rate in the group with a high rate of DNA synthesis (log10c.p.m. 3·0 or more) was significantly lower than that in the low-level group; the 5- and 10-year survival rates were 84 and 74 per cent for the low synthesis group (n = 46), and 60 and 46 per cent for the high synthesis group (n = 43) respectively. This was also noted in patients with stage 1 or 2 cancers, for whom the 5- and 10-year survival rates were 100 and 90 per cent for the low synthesis group (n = 25), and 75 and 70 per cent for the high synthesis group (n = 35). Multivariate analysis supported this significant correlation for DNA synthesis in the prognosis of patients after mastectomy. Furthermore, the level of DNA synthesis was significantly higher in 18 patients who died from a recurrence within 3 years after operation than in 56 survivors, and the level of DNA synthesis also correlated significantly with the survival period in the 33 patients who died. Conclusion: The level of DNA synthesis in breast cancer was variable, and was independent of the clinical stage or oestrogen receptor status. However, a high level of DNA synthesis was a positive indicator of a high risk of recurrence after operation, especially for stage 1 or 2 breast cancer. In vitro DNA synthesis may account for some of the clinical characteristics of breast cancers. © 1999 British Journal of Surgery Society Ltd

Nobuhiko Tanigawa - One of the best experts on this subject based on the ideXlab platform.

  • clinical significance of p glycoprotein expression and multidrug resistance assessed by in vitro Thymidine Incorporation Assay in patients with gastric carcinoma
    Gan to kagaku ryoho. Cancer & chemotherapy, 1994
    Co-Authors: Hidenori Fujii, Nobuhiko Tanigawa, Ryusuke Muraoka, M Yamakawa, Yasuhiko Masuda, Takumi Shimomatsuya, Yasushi Kato, Toshiharu Aotake, A Kitaoka, Toshiyuki Tanaka
    Abstract:

    : Drug resistance in chemotherapy is a significant problem in the treatment of gastric carcinomas as well as other malignant tumors. Multidrug resistant cells frequently overexpress the 170 kDa P-glycoprotein (P-gp). Twenty-four fresh tumor specimens of gastric carcinoma were assessed by flow cytometric detection of P-gp using monoclonal antibody C219. Eight patients were P-gp positive. Differentiated gastric carcinomas contained significantly higher concentrations of P-gp positive. Incidence of P-gp positive case was high in advanced stage. Sixteen cases received in vitro chemosensitivity test assessed by Thymidine Incorporation Assay (TIA). Seven of 9 multidrug resistant cases by TIA were P-gp positive, and all of 7 non-multidrug resistance were negative. Expression of P-gp and multidrug resistance were closely correlated (p < 0.01). Also, in 89 patients with operable gastric carcinoma, the relationship between multidrug resistance by TIA and their clinicopathologic features as well as their survival lengths were examined. Thirty-one of 89 specimens from gastric carcinoma patients were multidrug resistant by TIA. Patients with multidrug resistant group had a significantly poorer cumulative survival rate than non-multidrug resistant cases (p < 0.01). The multivariated analyses showed that multidrug resistance analyzed is useful indicator for prognosis (p < 0.1). We suggest that multidrug resistance cases or P-gp-positive cases of gastric carcinoma are highly malignant, and these determinations are clinically useful.

  • Detection of P-glycoprotein in solid tumors by flow cytometry.
    Anticancer Research, 1993
    Co-Authors: Hidenori Fujii, Nobuhiko Tanigawa, Takumi Shimomatsuya, R Muraoka, T Tanaka
    Abstract:

    : P-glycoprotein (P-gp) detection by FCM (flow cytometry) was correlated with P-gp detection by immunohistochemical staining or Western blotting in K562 cell lines variably resistant to doxorubicin (DOX). A strong correlation was noted between the flow cytometric data and the degree of resistance assessed by Thymidine Incorporation Assay (TIA). Of the human carcinomas tested, 37.5% were P-gp positive by flow cytometry. The flow cytometry data correlated strongly with the immunohistochemical staining (p < 0.001). Thirteen of the 15 P-gp positive tumors were resistant to DOX and vincristine (VCR) on TIA. Thus, P-gp detection by FCM correlates strongly with tumor sensitivity to DOX and VCR (p < 0.001).

  • in vitro chemosensitivity Assay using a double layer agar system human tumor cloning Assay and Thymidine Incorporation Assay
    Gan to kagaku ryoho. Cancer & chemotherapy, 1993
    Co-Authors: Nobuhiko Tanigawa, Talcumi Shimomatsuya, Ryusuke Muraoka, Hidenori Fujii, M Yamakawa, H Saitoh
    Abstract:

    : Human tumor cloning Assay (HTCA) and Thymidine Incorporation Assay (TIA) were both performed using a double-layer-agar system with continuous exposure of cells to standard anticancer drugs. The rate of evaluable Assays was 44% (280 of 638 tumor samples) in HTCA and 48% (216 of 452) in TIA. When the tumor samples were restricted to the gastric and colorectal cancers, it was significantly higher in TIA than HTCA (p < 0.01). HTCA was 95% reliable for predicting in vivo resistance and 52% reliable for in vivo sensitivity, whereas TIA was 88% reliable for in vivo resistance and 44% for in vivo sensitivity. These results seem to suggest that it is unnecessary to select just clonogenic tumor cells among whole tumor cell population in assessing chemosensitivity of human tumors. The current study also indicates that chemotherapy with in vitro sensitive drugs assessed by TIA produced longer survival of the patients with stage III or IV gastric cancer. Most of clinical correlation trials including this study, however, have been performed retrospectively. The prospective study is necessary to determine whether drug selection by in vitro Assays is superior to that by an experienced oncologist. In addition, further studies on pharmacokinetics of anticancer drugs are required to solve some other problems inherent to the current chemosensitivity Assays.

  • in vitro growth ability and chemosensitivity of gastric and colorectal cancer cells assessed with the human tumour clonogenic Assay and the Thymidine Incorporation Assay
    European Journal of Cancer, 1992
    Co-Authors: Nobuhiko Tanigawa, Hideki Morimoto, Naochika Dohmae, Talcumi Shimomatsuya, Kohji Takahashi, Ryusuke Muraoka
    Abstract:

    Abstract A human tumour cloning Assay (HTCA) has been performed on 191 samples of gastric and 152 samples of colorectal cancers, and a Thymidine Incorporation Assay (TIA) on 178 samples of gastric and 109 samples of colorectal cancers. The rate of evaluable Assays was significantly higher in the TIA than in the HTCA (P

K. Tamura - One of the best experts on this subject based on the ideXlab platform.

  • in vitro dna synthesis in freshly separated human breast cancer cells assessed by tritiated Thymidine Incorporation Assay relationship to the long term outcome of patients
    British Journal of Surgery, 1999
    Co-Authors: K. Tamura, Takashi Inamoto, K Ohgaki, H Kodama
    Abstract:

    Background: Tumour growth rate has a significant effect on the clinical course of various malignancies. The present study was designed to assess whether in vitro DNA synthesis in freshly separated breast cancer cells is a useful marker in evaluating growth rates and in predicting the clinical outcome of patients. Methods: From 1982 to 1992, DNA synthesis was assessed by [3H]Thymidine Incorporation in 97 samples of primary lesions from 94 patients with breast cancer. The patients were followed for 5–15 years and their outcome was surveyed in January 1998. Results: The level of DNA synthesis did not correlate with the patients' age, clinical stage or expression of oestrogen receptor. However, it correlated significantly with the histological grade. In 89 patients, whose outcome was reported, the survival rate in the group with a high rate of DNA synthesis (log10c.p.m. 3·0 or more) was significantly lower than that in the low-level group; the 5- and 10-year survival rates were 84 and 74 per cent for the low synthesis group (n = 46), and 60 and 46 per cent for the high synthesis group (n = 43) respectively. This was also noted in patients with stage 1 or 2 cancers, for whom the 5- and 10-year survival rates were 100 and 90 per cent for the low synthesis group (n = 25), and 75 and 70 per cent for the high synthesis group (n = 35). Multivariate analysis supported this significant correlation for DNA synthesis in the prognosis of patients after mastectomy. Furthermore, the level of DNA synthesis was significantly higher in 18 patients who died from a recurrence within 3 years after operation than in 56 survivors, and the level of DNA synthesis also correlated significantly with the survival period in the 33 patients who died. Conclusion: The level of DNA synthesis in breast cancer was variable, and was independent of the clinical stage or oestrogen receptor status. However, a high level of DNA synthesis was a positive indicator of a high risk of recurrence after operation, especially for stage 1 or 2 breast cancer. In vitro DNA synthesis may account for some of the clinical characteristics of breast cancers. © 1999 British Journal of Surgery Society Ltd

  • Internalization with high targeting potential of mouse monoclonal antibody ONS-M21 recognizing human malignant glioma antigen.
    Cancer letters, 1998
    Co-Authors: K. Shimizu, H Kawata, Y Sekimori, Yasuyoshi Miyao, Y. Yoshimura, K. C. Park, K. Tamura, Haruhiko Kishima, T. Hayakawa
    Abstract:

    In order to evaluate the targeting potential of mouse monoclonal antibody ONS-M21 recognizing a human astrocytoma- and medulloblastoma-associated antigen, the internalization ability of this antibody and the selective cytotoxicity in the toxin-conjugated form were examined. Internalization Assay with 125I-labeled ONS-M21 showed that about 20% of the total radioactivities was detected in the cellular fraction of human medulloblastoma cell line ONS-76 cells and that the reaction reached a plateau level in 30 min. To examine the selective delivery capacity of a high molecular substance in place of 125I, an immunotoxin was prepared with ricin A chain and ONS-M21 via disulfide bonds. A cytotoxic effect against ONS-76 cells was found with [3H]Thymidine Incorporation Assay using the immunotoxin, but not against antigen-negative HuH-7 and SW480 cells. These results suggest that ONS-M21 could effectively deliver toxins, chemotherapeutic agents or radionuclei to malignant glioma specifically.