Cellular uptake, cytotoxicity and DNA-binding studies of the novel imidazoacridinone antineoplastic agent C1311

C1311 is a novel therapeutic agent with potent activity against experimental colorectal cancer that has been selected for entry into clinical trial. The compound has previously been shown to have DNA-binding properties and to inhibit the catalytic activity of topoisomerase II. In this study, cellular uptake and mechanisms by which C1311 interacts with DNA and exerts cytotoxic effects in intact colon carcinoma cells were investigated. The HT29 colon cancer cell line was chosen to follow cellular distribution of C1311 over a time course of 24 h at drug concentrations that just inhibited cell proliferation by 50% or 100%. Nuclear uptake of C1311 and co-localization with lysosomal or mitochondrial dyes was examined by fluorescence microscopy and effects on these cellular compartments were determined by measurement of acid phosphatase levels, rhodamine 123 release or DNA-binding behaviour. The strength and mode of DNA binding was established by thermal melting stabilization, direct titration and viscometric studies of host duplex length. The onset of apoptosis was followed using a TUNEL assay and DNA-fragmentation to determine a causal relationship of cell death. Growth inhibition of HT29 cells by C1311 was concomitant with rapid drug accumulation in nuclei and in this context we showed that the compound binds to duplex DNA by intercalation, with likely A/T sequence-preferential binding. Drug uptake was also seen in lysosomes, leading to lysosomal rupture and a marked increase of acid phosphatase activity 8 h after exposure to C1311 concentrations that effect total growth inhibition. Moreover, at these concentrations lysosomal swelling and breakdown preceded apoptosis, which was not evident up to 24 h after exposure to drug. Thus, the lysosomotropic effect of C1311 appears to be a novel feature of this anticancer agent. As it is unlikely that C1311-induced DNA damage alone would be sufficient for cytotoxic activity, lysosomal rupture may be a critical component for therapeutic efficacy. © 1999 Cancer Research Campaig

Amifostine reduces the seminiferous epithelium damage in doxorubicin-treated prepubertal rats without improving the fertility status

<p>Abstract</p> <p>Background</p> <p>Amifostine is an efficient cytoprotector against toxicity caused by some chemotherapeutic drugs. Doxorubicin, a potent anticancer anthracycline, is known to produce spermatogenic damage even in low doses. Although some studies have suggested that amifostine does not confer protection to doxorubicin-induced testicular damage, schedules and age of treatment have different approach depending on the protocol. Thus, we proposed to investigate the potential cytoprotective action of amifostine against the damage provoked by doxorubicin to prepubertal rat testes (30-day-old) by assessing some macro and microscopic morphometric parameters 15, 30 and 60 days after the treatment; for fertility evaluation, quantitative analyses of sperm parameters and reproductive competence in the adult phase were also carried out.</p> <p>Methods</p> <p>Thirty-day-old male rats were distributed into four groups: Doxorubicin (5 mg/kg), Amifostine (400 mg/kg), Amifostine/Doxorubicin (amifostine 15 minutes before doxorubicin) and Sham Control (0.9% saline solution). "Standard One Way Anova" parametric and "Anova on Ranks" non-parametric tests were applied according to the behavior of the obtained data; significant differences were considered when p < 0.05.</p> <p>Results</p> <p>The rats killed 30 and 60 days after doxorubicin treatment showed diminution of seminiferous epithelium height and reduction on the frequency of tubular sections containing at least one type of differentiated spermatogonia; reduction of sperm concentration and motility and an increase of sperm anomalous forms where observed in doxorubicin-treated animals. All these parameters were improved in the Amifostine/Doxorubicin group only when compared to Doxorubicin group. Such reduction, however, still remained below the values obtained from the Sham Control group. Nevertheless, the reproductive competence of doxorubicin-treated rats was not improved by amifostine pre-administration.</p> <p>Conclusions</p> <p>These results suggest that amifostine promotes a significant reduction of the doxorubicin long-term side effects on the seminiferous epithelium of prepubertal rats, which is reflected in the epidydimal fluid parameters in the adult phase. However, fertility status results suggest that such protection may not be effective against sperm DNA content damage. Further investigation of sperm DNA integrity must be carried out using amifostine and doxorubicin-treated experimental models.</p

Viscum album L. extracts in breast and gynaecological cancers: a systematic review of clinical and preclinical research

<p>Abstract</p> <p>Background</p> <p><it>Viscum album </it>L. extracts (VAE, European mistletoe) are a widely used medicinal plant extract in gynaecological and breast-cancer treatment.</p> <p>Methods</p> <p>Systematic review to evaluate clinical studies and preclinical research on the therapeutic effectiveness and biological effects of VAE on gynaecological and breast cancer. Search of databases, reference lists and expert consultations. Criteria-based assessment of methodological study quality.</p> <p>Results</p> <p>19 randomized (RCT), 16 non-randomized (non-RCT) controlled studies, and 11 single-arm cohort studies were identified that investigated VAE treatment of breast or gynaecological cancer. They included 2420, 6399 and 1130 patients respectively. 8 RCTs and 8 non-RCTs were embedded in the same large epidemiological cohort study. 9 RCTs and 13 non-RCTs assessed survival; 12 reported a statistically significant benefit, the others either a trend or no difference. 3 RCTs and 6 non-RCTs assessed tumour behaviour (remission or time to relapse); 3 reported statistically significant benefit, the others either a trend, no difference or mixed results. Quality of life (QoL) and tolerability of chemotherapy, radiotherapy or surgery was assessed in 15 RCTs and 9 non-RCTs. 21 reported a statistically significant positive result, the others either a trend, no difference, or mixed results. Methodological quality of the studies differed substantially; some had major limitations, especially RCTs on survival and tumour behaviour had very small sample sizes. Some recent studies, however, especially on QoL were reasonably well conducted. Single-arm cohort studies investigated tumour behaviour, QoL, pharmacokinetics and safety of VAE. Tumour remission was observed after high dosage and local application. VAE application was well tolerated. 34 animal experiments investigated VAE and isolated or recombinant compounds in various breast and gynaecological cancer models in mice and rats. VAE showed increase of survival and tumour remission especially in mice, while application in rats as well as application of VAE compounds had mixed results. <it>In vitro </it>VAE and its compounds have strong cytotoxic effects on cancer cells.</p> <p>Conclusion</p> <p>VAE shows some positive effects in breast and gynaecological cancer. More research into clinical efficacy is warranted.</p

Outcomes According to ALK Status Determined by Central Immunohistochemistry or Fluorescence In Situ Hybridization in Patients With ALK-Positive NSCLC Enrolled in the Phase 3 ALEX Study.

We retrospectively examined progression-free survival (PFS) and response by ALK fluorescence in situ hybridization (FISH) status in patients with advanced ALK immunohistochemistry (IHC)-positive NSCLC in the ALEX study. A total of 303 treatment-naive patients were randomized to receive twice-daily alectinib 600 mg or crizotinib 250 mg. ALK status was assessed centrally using Ventana ALK (D5F3) CDx IHC and Vysis ALK Break Apart FISH Probe Kit. Primary end point is investigator-assessed PFS. Secondary end points of interest are objective response rate and duration. Investigator-assessed PFS was significantly prolonged with alectinib versus crizotinib in ALK IHC-positive and FISH-positive tumors (n = 203, 67%) (hazard ratio [HR] = 0.37, 95% confidence interval [CI]: 0.25-0.56; p &lt; 0.0001) and ALK IHC-positive and FISH-uninformative tumors (n = 61, 20%) (HR = 0.39, 95% CI: 0.20-0.78) but not in ALK IHC-positive and FISH-negative tumors (n = 39, 13%) (HR = 1.33, 95% CI: 0.6-3.2). Objective response rates were higher with alectinib versus crizotinib in ALK IHC-positive and FISH-positive tumors (90.6% versus 81.4%; stratified OR = 2.22, 95% CI: 0.97-5.07) and ALK IHC-positive and FISH-uninformative tumors (96.0% versus 75.0%; OR = 9.29, 95% CI: 1.05-81.88) but not in ALK IHC-positive and FISH-negative tumors (28.6% versus 44.4%; OR = 0.45, 95% CI: 0.12-1.74). Next-generation sequencing was performed in 35 of 39 patients with ALK IHC-positive and FISH-negative tumors; no ALK fusion was identified in 20 of 35 patients (57.1%) by next-generation sequencing, but 10 of 20 (50.0%) had partial response or stable disease. Outcomes of patients with ALK IHC-positive and FISH-positive and ALK IHC-positive and FISH-uninformative NSCLC were similar to those of the overall ALEX population. These results suggest that Ventana ALK IHC is a standard testing method for selecting patients for treatment with alectinib