Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.3.5.1 (succinate dehydrogenase)
 8,177 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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.
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PMID:Human colon cancer tissues are more sensitive than rectal cancer tissues to antitumor drugs in vitro. 199 40

In vitro thermosensitivity of various human tumors including 90 esophageal, 10 gastric and 40 colo-rectal cancers were evaluated using the succinate dehydrogenase inhibition (SDI) test. Tumor fragments minced with scissors were incubated at 43 degrees C as heat treated cells and at 37 degrees C as controls for 20 hrs, and assayed for the succinate dehydrogenase (SD) activity using 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT) as a hydrogen acceptor. The thermosensitivity was estimated by the percentage of SD activity of heat treated cells compared to that of each control. A variation in the thermosensitivity was noted between patients. The SD activity was 60.1 +/- 20.3% (mean +/- standard deviation) for esophageal cancers, 34.9 +/- 21.7% for gastric cancers, 50.3 +/- 20.6% for colo-rectal cancers. Significant differences were noted between esophageal cancers and gastric cancers, colo-rectal cancers (p less than 0.01 and p less than 0.05, respectively). When the thermosensitivity was arbitrarily defined as reduction in the SD activity to 50% of control or less, the positive rates were 31.1% for esophageal cancer, 70% for gastric cancer and 62.5% for colo-rectal cancer. Our results show that the SDI test is a useful method for determination of the thermosensitivity of clinical samples.
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PMID:[In vitro thermosensitivity of various human tumors evaluated using the SDI (succinate dehydrogenase inhibition) test]. 223 61

The sensitivity to heat and radiation of 22 rectal cancer tissues obtained at biopsy was studied using the in vitro succinate dehydrogenase inhibition test. The succinate dehydrogenase activity of tissue fragments was assayed after exposure at 43 degrees C (hyperthermia) for 20 hours, to radiation of 6 Gy, and to both heat (43 degrees C) and radiation (6 Gy). The sensitivity to each treatment was estimated by the percentage of succinate dehydrogenase activity of the treated cells compared with that of control cells. The mean plus or minus standard deviation of succinate dehydrogenase activity after exposure to radiation, heat, and both heat and radiation, was 84.7 +/- 12.6 percent, 52.9 +/- 20.7 percent, and 46.8 +/- 20.7 percent, respectively. The succinate dehydrogenase activities of heat-treated cells and both heat- and radiation-treated cells were significantly lower than that of the radiation-treated cells (P less than 0.01). The succinate dehydrogenase activities of heat plus radiation treated cells were the lowest in tissues from cancer lesions. Although the number was small, there was a correlation between this test and clinical outcome in seven of nine cases. Thus, preoperative therapy of hyperthermia plus radiotherapy is expected to be effective for treating patients with rectal cancer.
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PMID:Sensitivity to heat and radiation of human rectal malignant tissues in vitro. 236 27