H. Osswald

Clinical and genomic influence of sulindac on rectal mucosa in familial adenomatous polyposis

PURPOSE: A study was performed to evaluate the antiproliferative effects of low doses of the nonsteroidal drug, sulindac, on adenomas and rectal mucosa in familial adenomatous polyposis and to analyze the influence on tumor-suppressor genes and on apoptosis. METHODS: This was a prospective, controlled, nonrandomized Phase II dose-finding study for sulindac. The study group (n=28) and control group (n=10) underwent colectomy and ileorectal anastomoses, with repeated proctoscopy with endoluminal ultrasound and biopsies every three months. Dose-reduction of sulindac according to adenoma reversion was predetermined. Proliferation marker, Ki-67 (MIB1 and 5), on frozen or paraffin sections evaluated the antiproliferative effects; mutant p21ras,pantropic p53, mutant p53, and anti -bcl-2 were performed as enzyme-linked immunosorbent assay procedures and/or immunohistochemistry on paraffin sections. RESULTS: All patients responded to sulindac after 24 weeks (at the latest). There was a significant reduction of adenomas and dose reduction to 67 mg/day after three years of therapy (Manns test for trend,P<0.001). Results consisted of 78 percent complete reversions, 22 percent partial reversions of adenomas at latest re-examination, and no influence on upper gastrointestinal tract adenomas. No influence was detected on repeated hemograms, liver, or renal function at high or low doses. There was a permanent antiproliferative effect (Ki-67) of low-dose sulindac, significant blocking ofrasmutation activation, and a significant difference of untreated and treated mucosa in mutant p53 content (Wilcoxons or Kruskal-Wallis each,P<0.05). Reverse correlation of anti-bcl-2 and p53 immunostaining on mucosa sections was an indication of adenoma relapse. CONCLUSIONS: Low-dose antiproliferative sulindac therapy is highly effective in adenoma reversion in familial adenomatous polyposis patients. Sulindac shows influence on tumor-suppressor genes and on apoptosis markers. An immunostaining correlation indicates adenoma relapse in flat microadenomas in advance of macroscopic appearance. Low-dose sulindac treatment may develop into an additive permanent therapy for colectomized familial adenomatous polyposis patients.

ACTIVITY OF VARIOUS AMPHIPHILIC AGENTS IN REVERSING MULTIDRUG RESISTANCE OF L 1210 CELLS

Several compounds (bamipine, chlorphenoxamine, estracyt, hycanthone, quinidine, quinine, tamoxifen, trifluoperazine and verapamil) have a common basic structure with the following features: lipophilic aromatic ring system; linked chain hydrophilic N-alkyl group. They are used medically for varying diseases. Their activity in reversing multidrug-resistance (MDR) with other compounds (diethylstilbestrol, beta-estradiol, methylbiguanide, methylpiperazine, testosterone) lacking one of these chemical features is compared. The in vitro test system we used was the nucleoside incorporation assay using parental L 1210 ascites tumor cells and a doxorubicin resistant subline, which expresses the MDR phenotype. The substances lacking one of these features were not effective in reversing the MDR whereas all other tested substances demonstrated modulating potential in the MDR resistant L 1210 cells.

Decreased HER-2 tyrosine kinase expression in rectal mucosa of FAP patients following low-dose sulindac chemoprevention

As a part of the mechanisms of action in reversing FAP adenomas by the low-dose sulindac maintenance therapy (2 x 25 mg/patient per day), the extent of HER-2 proto-oncogene expression in the rectal mucosa seems to be of interest. Immunocytochemical analyses were performed in plasma and in rectal tissue of sulindac-treated FAP patients during an 18 months follow-up and compared with rectal tissue of patients with FAP, Crohns disease, or rectal cancer or with healthy volunteers. HER-2 was significantly reduced and maintained in tissue under sulindac chemoprevention below base line levels of healthy individuals, but not in plasma. Therefore, a direct or indirect effect of sulindac as a tyrosine kinase inhibitor may be implicated. During NSAID treatment HER-2 protein expression as a prognostic tool seems to be of little clinical relevance.

Potentiation of the chemotherapeutic action of 5-fluorouracil by combination with cytidine or guanosine on HRS-Sarcoma

SummaryThe chemotherapeutic action of 5-fluorouracil monotherapy on HRS-Sarcoma in mice was compared with those of 5-fluorouracil nucleoside combinations (thymidine, cytidine or guanosine). The curative action of 5-fluorouracil was potentiated without increasing its toxicity, when cytidine or guanosine were applied at definite intervals before or after 5-fluorouracil.ZusammenfassungDie chemotherapeutische Wirkung von 5-Fluorouracil wurde am HRS-Sarkom der Maus mit 5-Fluorouracil-Nucleois-Kombinationen (Thymidin, Cytidin, Guanosin) verglichen. Die curative Wirkung von 5-Fluorouracil wurde ohne Zunahme der Toxizität potenziert, wenn die Nucleoside Cytidin oder Guanosin in bestimmtem Zeitintervall vor oder nach der 5-Fluorouracil-Applikation erfolgte.

Sacrosine- and prolinedithiocarbamate pretreatment increases the therapeutic efficacy of doxorubicin, methotrexate, teniposide, mitoxantrone or cyclohexylchloroethylnitrosourea in leukemia L1210

SummaryThe influence of different doses of the hydrophilic sarcosine- or prolinedithiocarbamate on the chemotherapeutic efficacy of doxorubicin, teniposide, methotrexate, mitoxantrone or cyclohexylchlorethylnitrosourea was evaluated in female B6D2F1 mice bearing leukemia L1210, implanted intraperitoneally. The simultaneous administration of these dithiocarbamates and the drugs used induced no increase of the therapeutic efficacy of the combinations compared to the corresponding dose of the drug and simultaneously applied saline. The results indicate that the subcutaneous pretreatment with sarcosine- or prolinedithiocarbamate increased the therapeutic efficacy of the drugs used compared to the corresponding monotherapy, in which saline was applied in the same interval as the dithiocarbamate and the antineoplastic agents. Sarcosine- or prolinedithiocarbamate applied alone did not influence leukemia L1210. The increase of the efficacy of the drugs used by sequential combination with sarcosine- or prolinedithiocarbamate seems to be influenced predominantly by diminishing the toxicity as well as by modulating the chemotherapeutic action.

Suramin enhancement of the chemotherapeutic actions of cyclophosphamide or adriamycin of intramuscularly-implanted Ehrlich carcinoma.

The chemotherapeutic action of cyclophosphamide or adriamycin monotherapy on hyperdiploid Ehrlich carcinoma was compared with that of sequential combinations of suramin and cyclophosphamide and suramin and adriamycin. The chemotherapeutic action of the suramin-cyclophosphamide combination or of the adriamycin-surmin combination was significantly enhanced when the combination partners were applied at definite intervals.

The influence of sodium ascorbate, menadione sodium bisulfite or pyridoxal hydrochloride on the toxic and antineoplastic action of N-methylformamide in P 388 leukemia or M 5076 sarcoma in mice☆

The toxicity of daily subcutaneously applied 500 mg/kg N-methylformamide (NMF) during a period of 8 days in female CD-mice was ameliorated when 100 mg/kg sodium ascorbate, 60 mg/kg menadione bisulfite or 80 mg/kg pyridoxal hydrochloride were applied simultaneously. The comparison of the daily s.c. application of 360 mg/kg NMF with the intermittent s.c. injection of 720 mg/kg NMF with an interval of 48 h in P 388 leukemia showed that the daily application of NMF induced an increase of life span of 82% whereas the intermittent schedule effected a 142% increase of life span. The simultaneous combination of 360 mg/kg NMF with 60 mg/kg sodium ascorbate applied daily caused a 133% increase of life span and the simultaneous combination of 360 mg/kg NMF with 30 mg/kg menadione sodium bisulfite lead to a 126% increase of life span. The combined daily s.c. application of 360 mg/kg NMF with 30 mg/kg pyridoxal hydrochloride induced only a minimal difference compared to the daily application of 360 mg/kg NMF alone. The combination of 720 mg/kg NMF with 120 mg/kg sodium ascorbate applied in intervals of 48 h showed a 164% increase of life span. In advanced M 5076 sarcoma the daily s.c. application of 360 mg/kg NMF effected a 82% increase of life span and the combination of 360 mg/kg NMF with 60 mg/kg sodium ascorbate effected a 135% increase of life span.

The effect of methotrexate pretreatment on 5-fluorouracil kinetics in sarcoma 180 in vivo

Synergy of sequential MTX and 5-FU has been shown in several in vitro and in vivo systems. In the present study the influence of time interval between MTX and 5-FU and MTX dose on 5-FU accumulation in tumor cells has been examined in Sarcoma 180 in vivo. There was a clear relationship between MTX dose applied and amount of 5-FU detected in the acid-soluble fraction, the RNA fraction and the thymidylate synthase complex fraction. Also, the MTX-5-FU time interval affected clearly the amount of 5-FU detected in all three fractions, the optimum time interval being 8-12 hr. The results indicate that for sequential application of MTX and 5-FU selection of an adequate MTX dose and a sufficient time interval is crucial to achieve synergistic action.

Folinic acid effect on 5-fluorouracil kinetics in vivo

SummarySynergy of folinic acid and FU has been shown in several experimental systems. In the present study we examined the kinetics of concurrent administration of folinic acid on the kinetics of FU in an in vivo model. Folinic acid significantly increased the amount of FU bound to the TS complex. In the sequential combination of MTX and FU folinic acid had no additional effect. The amount of FU incorporated into RNA was not affected in any of the treatment groups. The results indicate that folinic acid may improve FU cytotoxicity by increased FU binding to TS but has no additional effect on the synergistic sequential MTX-FU combination

Polyamine responses in a solid transplanted tumor (S180) in liver and in urine during endotoxin‐induced tumor injury in the mouse

Polyamine (PA) and ATP concentrations have been measured in the S180 sarcoma damaged by endotoxin (1) 4 hours after administration, coinciding with the onset of hemorrhage, (2) at 8 hours,and (3) at 24 hours, preceding overt necrosis. The putrescine (PU) content increased promptly, the spermidine (SPD) level dropped by 30% between 8 and 24 hours, while the spermine (SPM) concentration remained unchanged. The ATP level fell, reaching 1% of the control value at 24 hours. The parallel between increases in tumor PU content and urinary PU excretion appears to be largely fortuitous; no similar correlations existed in the cases of SPD and SPM. The development of tumor stasis and the alterations seen in PA metabolism of tumor‐free controls suggest that the changes in liver PA concentrations and in urinary excretion primarily reflect responses of nonmalignant cells. Both these findings in animals without tumors and existing data from other experimental systems are consistent with the thesis that PA response patterns to a particular procedure are qualitatively similar regardless of the presence or absence of a malignant growth, and are characteristic of the procedure employed.