Human colon cancer tissues are more sensitive than rectal cancer tissues to antitumor drugs in vitro

The chemosensitivities of 62 human colon cancer tissues, 67 rectal cancer tissues and 31 tumor-adjacent normal mucosal tissues were determined using the in vitro succinate dehydrogenase inhibition (SDI) test. These tissues obtained at the time of surgery were exposed to carboquone (CQ), adriamycin (ADM), mitomycin C (MMC), aclacinomycin A (ACR), cisplatin (DDP) and 5-fluorouracil (5-FU). The chemosensitivity was considered as positive when succinate dehydrogenase (SD) activity of the drug-treated cells decreased to below 50% of that of control cells, on day 3 of exposure. Decrease in the SD activity was noted in the colon cancer tissues, compared to the rectal cancer tissues, exposed to six antitumor drugs and in particular, to CQ (p less than 0.05), DDP (p less than 0.01) and ACR (p less than 0.05, one-sided paired t test). Decrease in the SD activity was noted in the tumor tissues, compared to the tumor-adjacent normal tissues, exposed to CQ, MMC and ACR (p less than 0.01). The sensitive rates were higher in the colon cancer tissues than the rectal cancer tissues, against all six antitumor drugs. Our findings show that the rectal cancer tissues are resistant to antitumor drugs, compared to the colon cancer tissues in vitro. When selecting antitumor drugs to treat patients with a rectal cancer, the assessment for chemosensitivity of the related tissues is crucial.     

Succinate dehydrogenase inhibition test for evaluating head and neck tumors

In vitro chemosensitivity was evaluated in human head and neck cancers using the succinate dehydrogenase (SD) test and the results were compared to findings in cases of malignant lymphomas and gastric cancers. Tumor fragments were exposed to several antitumor drugs at ten times the peak plasma concentration and assayed for SD activity. Decrease of SD activity was most prominent in the malignant lymphomas in cases of exposure to ADM, ACR, DDP, MMC and CQ; in which the average of SD activity decreased to below 30%. In the squamous cell carcinomas, SD activity below 40% was also observed with the same drugs, while the SD activity of gastric cancers was about 50%. There was a change of chemosensitivity following chemotherapy. The use of the SDI test will aid in selecting drugs for the prevention of recurrence or metastasis in head and neck cancers.     

Lung adenocarcinoma is more sensitive than gastric adenocarcinoma to anticancer drugs in vitro

The chemosensitivities of 26 lung adenocarcinoma tissues were compared to those of 110 gastric adenocarcinoma tissues, using the in vitro succinate dehydrogenase inhibition (SDI) test. Tumour tissues obtained at surgery were exposed to five different anticancer drugs: carboquone (CQ), adriamycin (ADM), mitomycin C (MMC), cisplatin (DDP) and 5-fluorouracil (5-FU). The lung adenocarcinomas showed a statistically significant reduction in succinate dehydrogenase (SD) activity, compared to the gastric adenocarcinomas, after exposure to each drug. The chemosensitivity was defined as a reduction in SD activity to 50% of control or less. Lesser degrees of reduction in SD activity were defined as drug resistance. The sensitivity rates to ADM, MMC and DDP, respectively, were significantly higher in the lung than in the gastric adenocarcinomas. Tumour cells from 22 (84.6%) of the 26 lung adenocarcinoma tissues showed a sensitivity to more than three drugs, whereas the rate was only 46.4% (51/110) for the gastric adenocarcinomas. The rate of resistance to all the drugs tested was 3.8% (1/26) for the lung adenocarcinomas, in contrast to the 20.9% (23/110) seen with the gastric adenocarcinomas. Thus, while adenocarcinomas of the lung and stomach both show clinical resistance to anticancer agents, the chemosensitivity of the lung tissues is greater. In the light of these observations, attention must be directed to improving specific drug delivery systems.     

Resistance to anticancer drugs of well differentiated gastric adenocarcinoma with venous invasion.

A comparison of the chemosensitivity of well-differentiated human gastric cancer tissues was made between histological venous invasion positive (v(+)) and negative (v(-)) tissues, using the succinate dehydrogenase inhibition (SDI) test. These tissues obtained at the time of surgery were exposed to six anticancer drugs: carboquone (CQ), adriamycin (ADM), mitomycin C (MMC), aclacinomycin A (ACR), cisplatin (DDP) and 5-fluorouracil (5-FU). Chemosensitivity was judged to be positive when the succinate dehydrogenase (SD) activity of the drug exposed cells decreased to below 50% of that of control cells. Decrease in the SD activity was more apparent in the v(-) tissues than in the v(+) tissues, exposed to the anticancer drugs and in particular to ADM (P less than 0.01), MMC (P less than 0.02) and DDP (P less than 0.05). The sensitivity rates to all six anticancer drugs were lower in the v(+) tissues. The resistance rates to all drugs tested were 0% in the v(-) tissues, but 21% in the v(+) tissues. In light of these observations, patients with gastric cancer of the well differentiated type and the histological venous invasion, will probably show a less positive response to cancer chemotherapy.     

Chemosensitivity differences between primary and metastatic lesions of clinical gastric cancer

An in vitro chemosensitivity test, the succinate dehydrogenase inhibition (SDI) test, was used to examine 16 pairs of samples obtained simultaneously from primary and metastatic lesions of clinical gastric cancer. Concerning the metastases, 11 were in the lymph nodes and five in the liver. The chemosensitivities of metastatic lesions against six anti-tumour drugs, carboquone (CQ), adriamycin (ADM), mitomycin C (MMC), aclacinomycin A (ACR), and 5-fluorouracil (5-FU), differed from those in the primary lesions, and there were no correlations of chemosensitivities between the primary and the metastatic lesions against these drugs, except for DDP. The lymph nodes were more sensitive to CQ, ADM, MMC, DDP, ACR and 5-FU, while the liver was less sensitive than the primary lesions to CQ, ADM, MMC, DDP, and ACR. Our findings indicate that in patients with lymph node metastasis, there is a sensitivity to anti-tumour drugs, while in cases of liver metastasis, drug treatment may be less effective. We propose that chemosensitivity testing should be done when attempting to design anti-tumour drugs.     

Tumor tissue is more sensitive to mitomycin C, carboquone, and aclacinomycin A than is adjacent normal tissue in vitro

In tissues obtained from patients undergoing gastrectomy or colectomy, sensitivity to mitomycin C (MMC), carboquone (CQ), and aclacinomycin A (ACR) was examined in 20 tumors (15 gastric, 5 colorectal) and in the adjacent normal mucosal tissues, using the in vitro succinate dehydrogenase inhibition test. The succinate dehydrogenase (SD) activity decreased to a greater extent in the tumor tissues than in adjacent normal tissues, at rates of 80% for MMC, 80% for CQ, and 90% for ACR. There were no correlations between SD activities of tumor and adjacent normal tissue, r = 0.157 for MMC, r = 0.435 for CQ, and r = 0.375 for ACR. Normal tissues were sensitive to MMC in 25% of cases sensitive to MMC in the tumor tissues, 46% for CQ, and 38% for ACR. These results show that the antitumor effects of MMC, CQ, and ACR are relatively specific for tumor tissues and that the assay of chemosensitivity of normal tissues is meaningful for predicting the toxic effects of antitumor drugs on these tissues.     

Comparison between succinate dehydrogenase inhibition test and subrenal capsule assay for chemosensitivity testing

The chemosensitivity result of the succinate dehydrogenase inhibition (SDI) test was compared with that of the subrenal capsule (SRC) assay in 23 human tumor tissues exposed to adriamycin (ADM), mitomycin C (MMC), cisplatin (DDP) and 5-fluorouracil (5-FU). The chemosensitivity was considered as positive when the succinate dehydrogenase (SD) activity of the drug-exposed cells was decreased to below 50% of that of control cells on day 3 in the SDI test, and the tumor size on day 6 was decreased to below -10% of that on day 0 in the SRC assay. Correlation rates between the decrease of SD activity in the SDI test and the decrease of tumor size in the SRC assay, using 23 evaluable cases in both assays, were r = 0.717 for ADM, r = 0.699 for MMC, r = 0.796 for DDP and r = 0.735 for 5-FU. The correlations of the chemosensitivity results were 73.9% for ADM, 73.9% for MMC, 82.6% for DDP and 60.9% for 5-FU. A positive correlation was noted between the in vitro and in vivo chemosensitivity results. This SDI test can serve as an effective tool for chemosensitivity testing.     

In vitro succinate dehydrogenase chemosensitivity of gastric carcinoma—relationship to DNA content

Summary Relationships between in vitro chemosensitivity and cell nuclear DNA content were investigated in malignant cells from 41 patients exhibiting advanced gastric carcinoma. The chemosensitivity was evaluated by measuring the succinate dehydrogenase (SD) activity in drug-exposed cancer cells and the DNA content was microspectrophotometrically determined. Following exposure of malignant tissue to carboquone (CQ) and cisplatin (DDP), the mean SD activity in cells displaying a relatively regular DNA distribution (type II) was significantly higher than that in those exhibiting a widely scattered DNA distribution (type IV;P<0.01 in CQ,P<0.05 in DDP). A similar tendency was recognized in cells that were treated with aclacinomycin A (ACR), Adriamycin (ADM), and mitomycin C (MMC). Such a decrease in SD activity in cells exhibiting a type IV pattern was remarkable, especially in cases undifferentiated adenocarcinoma. Mitotic counting analysis revealed a significantly higher value for DNA pattern type IV as compared with the findings for type II (P<0.01). These results demonstrate that gastric carcinoma displaying a high malignant potentiality shows a better response to antitumor drugs. Adjuvant chemotherapy prescribed following drug-sensitivity testing should be effective against such tumors.     

In vitro chemosensitivity of various human tumors evaluated by the SDI (succinate dehydrogenase inhibition) test

In vitro chemosensitivity was evaluated by SDI test in various human tumors including 1 lymph node metastasis of esophageal cancer, 10 gastric cancers, 4 colo-rectal cancers, 1 hepatoma, 2 lung cancers, 2 breast cancers and 1 gallbladder cancer. Tumor fragments cut with scissors were exposed to twelve kinds of antitumor drugs at five to ten times peak plasma concentration. After 3 days at 37 degrees C, each tumor fragment suspension was washed with phosphate-buffered saline and assayed for succinate dehydrogenase (SD) activity using 3-(4,5- dimethyl-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT) as a hydrogen acceptor. When the SD activity of the drug-treated cells was reduced to below 50% that of control cells, the chemosensitivity to the antitumor drug was considered positive. The chemosensitivity of each tumor varied individually. Mitomycin C or 5-fluorouracil are regularly used to treat gastric cancer patients, but, some specimens of gastric cancer in this study showed a resistance to these drugs and an unexpected sensitivity to other drugs. Our results show that the SDI test is a convenient method for clinical use and gives significant information about drug sensitivity.     

Sarcoma-180 cells and human colorectal tumor cells under in vitro hypoxic conditions are more sensitive to mitomycin C and carboquone

The effects of oxygen concentration on the chemosensitivity of mouse sarcoma-180 (S-180) cells and human colorectal cancer tissues to mitomycin C (MMC) or carboquone (CQ) were determined in vitro, since evidence had been obtained that these drugs are more effective in HeLa cells. The results were as follows: (a) S-180 cells exposed to various concentrations of MMC or CQ for 2 h under conditions of normal aeration (about 20%) or hypoxia (5.0% and 0%) were then maintained under normal conditions of aeration for 3 days. Change of viability was assessed by succinate dehydrogenase (SD) activity. With exposure of the cells to MMC or CQ, under anoxic conditions (O2:0%), SD activity decreased to a greater extent than seen in the control cells. The value for CQ was from 61.5% to about 36.2%. (b) The decrease in the SD activity of 20 colorectal cancer tissues kept under conditions of anoxia was compared with findings under normally aerated conditions, following exposure to 30 microM of MMC or 1.6 microM of CQ. On exposure to MMC or CQ under anoxic conditions, SD activity decreased significantly, compared with normally aerated conditions (P less than 0.001 for MMC; P less than 0.05 for CQ). As colorectal cancer is less sensitive than other tissues to various chemotherapeutic agents, we recommend that MMC and CQ be prescribed to treat patients with these malignant lesions.     

Chemosensitivity testing of anticancer agents in head and neck tumors. I: Comparison between head and neck squamous cell cancers and thyroid cancers

In vitro chemosensitivity was evaluated in 28 patients with head and neck squamous cell carcinomas (12 pharyngeal cancers, 7 oral cavity cancers, 4 laryngeal cancers, 4 maxillary sinus cancers and 1 esophageal cancer) and 19 patients with thyroid cancer. Tumor fragments obtained at biopsy or surgery were exposed to anticancer drugs and assayed for succinate dehydrogenase (SD) activity. The average of SD activity in squamous cell carcinomas was 63.2% for 5-FU, 24.6% for HCFU, 26.1% for CDDP, 41.0% for ADM, 28.4% for THP-ADM, 27.1% for ACR, 27.4% for CQ and 45.3% for VLB. In thyroid cancers, the average SD activity was 73.9% for 5-FU, 16.7% for HCFU, 32.6% for CDDP, 48.3% for ADM, 38.3% for THP-ADM, 57.3% for ACR, 39.0% for CQ and 75.3% for VLB. The SD activity inhibition rate by anticancer drugs was larger in cases of head and neck squamous cell carcinomas than in cases of thyroid cancers except for HCFU. Higher sensitivity to each antitumor drug detected in cancer tissues from metastatic lymph-nodes than in tissues from primary lesions needs further investigation.     

Evaluation of predictability of in vitro SDI assay in comparison with in vivo nude mouse assay

Twenty lines of human gastro intestinal and breast cancer xenografts, in which chemosensitivity spectra by the in vivo nude mouse assay had been clarified. were subjected to the in vitro SDI (succinate dehydrogenase inhibition) assay using MTT dye to assess the accuracy of this drug sensitivity test against 4 drugs i.e., mitomycin C (MMC), adriamycin (ADM) 5 fluorouracil (5-FU), and cisplatin (CDDP). After 3 days incubation, the suspension of every tumor cells including small fragments showed a marked decrease of SD activity even when no anticancer drug was added to the assay medium. Among these 4 drugs evaluated MMC exhibited a statistically significant correlation between chemosensitivity values of the in vitro SDI assay and those of the nude mouse assay. However, the other 3 drugs demonstrated no correlation between the values of these two methods. Since the primary cultured fibroblasts revealed, in general, lower sensitivity to these drugs, contamination of fibroblast may decrease the SDI values when materials from solid tumors with rich stroma such as a type of stomach cancer were subjected. It is considered that the prediction of chemosensitivity to every drug will be impossible by a in vitro SDI assay.     

Cytotoxicity of mitomycin C and carboquone combined with hyperthermia against hypoxic tumor cells in vitro.

Enhancement of the cytotoxicity of mitomycin C (MMC) and carboquone (CQ) by hypoxia at elevated temperature was examined using the SDI test of mouse Sarcoma 180 and Ehrlich cells and clonogenic assay of HeLa cells. When Sarcoma 180 and Ehrlich cells were incubated at 43 degrees C for 2-10 h, the hyperthermic effect was enhanced by hypoxia. The succinate dehydrogenase activity of the cells was reduced by hyperthermia to a greater extent in the presence of hypoxia (O2:5%) than under conditions of aeration (O2:20%). When the cells were exposed to various concentrations of MMC and CQ, under hypoxia, activity of the drugs was enhanced compared to the findings under conditions of aeration. The enhancement was prominent in case of drugs and hyperthermia combined. Clonogenicity of hypoxic HeLa cells was also reduced to a greater extent with this combination than in case of aerated cells. We tentatively speculate that hyperthermo-chemotherapy using MMC and CQ has a potential to attack selectively hypoxic cells present in a solid tumor.     

In vitro chemosensitivity of various human tumors evaluated by the succinate dehydrogenase inhibition (SDI) test (2)

In vitro chemosensitivity was evaluated by succinate dehydrogenase inhibition (SDI) test in 94 human tumors including 59 gastric cancers, 27 colo-rectal cancers and 8 malignant lymphomas. Tumor fragments were exposed to 12 kinds of antitumor drugs at ten times peak plasma concentration. Evaluable rates were 86/94 (91%) for all cases, 56/59 (95%) for gastric cancers, 22/27 (81%) for colo-rectal cancers and 8/8 (100%) for malignant lymphomas. The mean of SD activity was decreased to 48% of that of control cells with aclacinomycin, 49% with carboquone, 53% with actinomycin D, 54% with mitomycin C and 54% with daunomycin for gastric cancers, 59% with adriamycin for colo-rectal cancers and 33% with cyclophosphamide (40487 S), and 33% with actinomycin D, 37% with vinblastine and 39% with adriamycin for malignant lymphomas. When the SD activity was reduced to below 50% by antitumor drugs, the chemosensitivity was defined as positive. The antitumor drugs which had a higher chemosensitive-positive rate were aclacinomycin, carboquone and mitomycin C for gastric cancers, adriamycin for colo-rectal cancers and 40487 S, daunomycin and vinblastine for malignant lymphomas. Our results suggest that the origin of a tumor is a critical factor in its chemosensitivity.     

Modulation of cytotoxicity of cytostatic drugs by hemodialysis in vitro and in vivo

For most cytotoxic substances there are no established guidelines on how to deal with overdosage. Little is known about the dialysability of cytostatic drugs. To obtain further information, human plasma was incubated with cytostatic drugs and dialysed in vitro, using 'minimodules' with capillaries identical to those in clinical use. Cytotoxicity before and after dialysis was measured in a biological test system using permanent human lymphoblast cultures (LS2). The 20 cytostatic drugs studied were categorized as follows: (1) Dialysability in vitro. Good: methotrexate (MTX), 5-fluorouracil (5-FU/5-FUdR), cytarabine (ARAC), actinomycin D (DACT), mitomycin C (MMC), 4-OH-cyclophosphamide (4-OH-CPM), ifosfamide (IFO), melphalan (L-PAM), dacarbazine (DTIC), cisplatin (DDP). Intermediate: Adriamycin (ADM), 4'-epi-doxorubicin (4'-EA), carmustine (BCNU). Ineffective: daunorubicin (DNR), vincristine (VCR), vinblastine (VBL), vindesine (VDS), etoposide (VP-16), teniposide (VM-26), mitoxantrone (MITOX). These in vitro results cannot be transferred automatically into the in vivo situation because of specific drug distribution and metabolic rates. Considering pharmacokinetic data from the literature, the following recommendations can be made for practical clinical purposes. (2) Detoxification by hemodialysis in vivo. Possibly effective: MTX, 5-FU, MMC, CPM, IFO, L-PAM, BCNU, DTIC. Ineffective: ADM, 4'-EA, DNR, MITOX, DACT, VP-16, VM-26, VCR, VBL, VDS, ARAC, DDP.     

Therapeutic efficacy and pharmacokinetics of vindesine and vindesine-cisplatin in previously treated patients with non-small cell lung carcinoma

Twenty-nine patients with non-small cell lung cancer refractory to prior therapy were treated with either vindesine (VDS) alone (3 mg/m2 every week) or the combination of VDS plus cisplatin (DDP) (100 mg/m2 every 28 days). Serial blood and urine samples were collected to assess the pharmacokinetics of VDS and DDP. All patients were evaluable for toxicity and 27 were evaluable for response. No objective antitumor responses were observed. Peripheral neuropathy manifested by paresthesias, muscle weakness, and constipation were observed in 20 treated patients, and hematologic toxicity consisting of thrombocytopenia and/or leukopenia occurred in 18 patients. The plasma and urinary pharmacokinetics of VDS and DDP measured in this study indicate that VDS and DDP do not interfere with each other and that the pharmacokinetics in previously treated and untreated patients are similar. The antitumor responses and degree of toxicity observed in this trial compare unfavorably with previously reported VDS and VDS-DDP trials in previously untreated patients with this disease and suggest that prior exposure to chemotherapy might both decrease antitumor activity and enhance toxicity of these chemotherapeutic agents.     

Synergistic antitumor activity of combination chemotherapy with mitomycin C and cisplatin against human gastric cancer xenografts in nude mice

A new combined cancer chemotherapy regimen of mitomycin C (MMC) and cisplatin (DDP) showed synergistic antitumor activity against human gastric cancer xenografts St-40 and SC-1-NU in BALB/c nu/nu mice. The drugs were administered intraperitoneally at doses of 2 or 4 mg/kg for MMC and 3 or 6 mg/kg for DDP, respectively. To clarify the schedule-dependent antitumor activity of MMC and DDP against St-40 and SC-1-NU, different sequential therapies were conducted. Simultaneous administration of these agents showed the highest antitumor activity against SC1-NU among the three regimens used, whereas the sequence of MMC followed by DDP showed higher antitumor activity than the reverse sequence against St-40. The intratumoral concentration of platinum was significantly increased in St-40 treated with the sequence MMC to DDP, in comparison with the sequence DDP to MMC. The maximum tolerated dose (MTD) of this combination was 4 mg MMC plus 6 mg DDP per kg in all the combinations, and these MTDs were 2/3 of the corresponding values for their single use. Since this combination increased the antitumor activity of each single agent without any increase in their toxicity, it would appear to be useful clinically. © 1994 Wiley-Liss, Inc.     

Combined effect of HO-221 with various antitumor agents against L 1210 leukemia

Combined effect of N-[4-(5-bromo-2-pyrimidinyloxy)-3-chlorophenyl]-N'-(2-nitrobenzoyl ) urea, HO-221, with various antitumor agents was studied using L 1210 leukemia in vivo and in vitro. Ten anticancer drugs were chosen from alkylating agents, antitumor antibiotics, antimetabolites and plant alkaloids each. The combined effect was assessed by comparing ILS (increase of life span) in the combined group with the sum of ILS of each single agent. Synergistic effect was considered to exist if ILS of the combination-treatment group exceeds the sum of those in 2 single-treatment groups. The two-drug combination of HO-221 with cyclophosphamide (CPA), adriamycin (ADM), mitomycin C (MMC), vindesine (VDS), vincristine (VCR) or etoposide showed remarkable synergistic effects with 60-days survivors. However, the combination chemotherapy with antimetabolites, 5-fluorouracil (5-FU) and methotrexate (MTX) showed competitive effects. Moreover, the synergistic cytocidal effect in vitro by the clonogenic assay was observed in combination of HO-221 with the same drug using in vivo test. The present results indicate that HO-221 seems to be a useful antitumor agent in combination chemotherapy.     

Chemosensitivity test for carcinoma of digestive organs

For the chemosensitivity for carcinoma of digestive organs, gastric, colorectal, and hepatic cancer tissues were examined using in vitro succinate dehydrogenase inhibition (SDI) test and in vivo subrenal capsule (SRC) assay. The chemosensitivity varied in the tissue. The origin of an organ tumor, histological differentiation, and difference of primary or metastatic lesions are critical for determining chemosensitivity. Biochemical analysis shows that antitumor drugs have an increased susceptibility in tissues with high activity of pyrimidine nucleotide synthesis.     

人肺癌细胞体外对抗癌药物敏感性的初探

目的探讨人肺癌细胞体外对１０种抗癌药的敏感性及方法的可靠性。方法收集人肺癌手术切除的标本２０例，用一简单、快速，有一定特异性优点的ＭＴＴ（３－（４，５）－双甲基－２－唑噻－（２，５）－二苯基溴化四氮唑蓝）法作威猛、足叶乙甙、阿霉素、长春新碱、长春地辛、卡铂、平阳霉素、氟脲嘧啶、环磷酰胺和异环磷酰胺抗癌敏感药物试验。结果患者不同个体之间药物敏感性不同（Ｐ＜０．０１）：１０种药物平均抑制率以威猛类药物最高（Ｐ＜０．０１），依次为阿霉素、卡铂、足叶乙甙、长春地辛等。敏感药物顺序与临床治疗结果大致相符。结论用ＭＴＴ法可作肿瘤治疗个案化较为可靠的检测方法。